treewide: convert to tpm_result_t

Convert TPM functions to return TPM error codes(referred to as
tpm_result_t) values to match the TCG standard.

BUG=b:296439237
TEST=build and boot to Skyrim
BRANCH=None

Change-Id: Ifdf9ff6c2a1f9b938dbb04d245799391115eb6b1
Signed-off-by: Jon Murphy <jpmurphy@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77666
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

44 files changed, 734 insertions, 653 deletions

diff --git a/src/drivers/crb/tis.c b/src/drivers/crb/tis.c
index 40a3513511..cdb0dbb612 100644
--- a/src/drivers/crb/tis.c
+++ b/src/drivers/crb/tis.c
@@ -35,50 +35,52 @@ static const char *tis_get_dev_name(struct tpm2_info *info)
 	return "Unknown";
 }
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	if (tpm_is_open) {
 		printk(BIOS_ERR, "%s called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if (CONFIG(HAVE_INTEL_PTT)) {
 		if (!ptt_active()) {
 			printk(BIOS_ERR, "%s: Intel PTT is not active.\n", __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 		printk(BIOS_DEBUG, "%s: Intel PTT is active.\n", __func__);
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	struct tpm2_info info;
 
 	// Wake TPM up (if necessary)
-	if (tpm2_init() != 0)
-		return -1;
+	tpm_result_t rc = tpm2_init();
+	if (rc)
+		return rc;
 
 	tpm2_get_info(&info);
 
 	printk(BIOS_INFO, "Initialized TPM device %s revision %d\n", tis_get_dev_name(&info),
 	       info.revision);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size, uint8_t *recvbuf, size_t *rbuf_len)
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+					uint8_t *recvbuf, size_t *rbuf_len)
 {
 	int len = tpm2_process_command(sendbuf, sbuf_size, recvbuf, *rbuf_len);
 
 	if (len == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	*rbuf_len = len;
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void crb_tpm_fill_ssdt(const struct device *dev)
@@ -118,28 +120,28 @@ static const char *crb_tpm_acpi_name(const struct device *dev)
 }
 
 #if CONFIG(GENERATE_SMBIOS_TABLES) && CONFIG(TPM2)
-static int tpm_get_cap(uint32_t property, uint32_t *value)
+static tpm_result_t tpm_get_cap(uint32_t property, uint32_t *value)
 {
 	TPMS_CAPABILITY_DATA cap_data;
 	int i;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	if (!value)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 
 	rc = tlcl_get_capability(TPM_CAP_TPM_PROPERTIES, property, 1, &cap_data);
 
 	if (rc)
-		return -1;
+		return rc;
 
 	for (i = 0 ; i < cap_data.data.tpmProperties.count; i++) {
 		if (cap_data.data.tpmProperties.tpmProperty[i].property == property) {
 			*value = cap_data.data.tpmProperties.tpmProperty[i].value;
-			return 0;
+			return TPM_SUCCESS;
 		}
 	}
 
-	return -1;
+	return TPM_CB_FAIL;
 }
 
 static int smbios_write_type43_tpm(struct device *dev, int *handle, unsigned long *current)
diff --git a/src/drivers/crb/tpm.c b/src/drivers/crb/tpm.c
index e919137ea4..4e9f6f2d2b 100644
--- a/src/drivers/crb/tpm.c
+++ b/src/drivers/crb/tpm.c
@@ -67,7 +67,7 @@ static void crb_readControlArea(void)
 }
 
 /* Wait for Reg to be expected Value  */
-static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mask,
+static tpm_result_t crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mask,
 			      uint32_t expectedValue)
 {
 	uint32_t regValue;
@@ -81,13 +81,13 @@ static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mas
 		regValue = read32(addr);
 
 		if ((regValue & mask) == expectedValue)
-			return 0;
+			return TPM_SUCCESS;
 
 		if (stopwatch_expired(&sw)) {
 			printk(BIOS_ERR,
 			       "CRB_WAIT: Error - Timed out with RegValue: %08x, Mask: %08x, Expected: %08x\n",
 			       regValue, mask, expectedValue);
-			return -1;
+			return TPM_CB_TIMEOUT;
 		}
 	}
 }
@@ -96,27 +96,27 @@ static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mas
  *
  * Checks if the CRB Interface is ready
  */
-static int crb_probe(void)
+static tpm_result_t crb_probe(void)
 {
 	uint64_t tpmStatus = read64(CRB_REG(cur_loc, CRB_REG_INTF_ID));
 	printk(BIOS_SPEW, "Interface ID Reg. %llx\n", tpmStatus);
 
 	if ((tpmStatus & CRB_INTF_REG_CAP_CRB) == 0) {
 		printk(BIOS_DEBUG, "TPM: CRB Interface is not supported.\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if ((tpmStatus & (0xf)) != 1) {
 		printk(BIOS_DEBUG,
 		       "TPM: CRB Interface is not active. System needs reboot in order to active TPM.\n");
 		write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_SEL);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_SEL);
 	write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_LOCK);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -129,7 +129,7 @@ static uint8_t crb_activate_locality(void)
 	uint8_t locality = (read8(CRB_REG(0, CRB_REG_LOC_STATE)) >> 2) & 0x07;
 	printk(BIOS_SPEW, "Active locality: %i\n", locality);
 
-	int rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750,
+	tpm_result_t rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750,
 				    LOC_STATE_LOC_ASSIGN, LOC_STATE_LOC_ASSIGN);
 
 	if (!rc && (locality == 0))
@@ -141,15 +141,15 @@ static uint8_t crb_activate_locality(void)
 	rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750, LOC_STATE_LOC_ASSIGN,
 				LOC_STATE_LOC_ASSIGN);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - No Locality has been assigned TPM-wise.\n");
+		printk(BIOS_ERR, "TPM: Error (%#x) - No Locality has been assigned TPM-wise.\n", rc);
 		return 0;
 	}
 
 	rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 1500,
 				LOC_STATE_REG_VALID_STS, LOC_STATE_REG_VALID_STS);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - LOC_STATE Register %u contains errors.\n",
-		       locality);
+		printk(BIOS_ERR, "TPM: Error (%#x) - LOC_STATE Register %u contains errors.\n",
+		       rc, locality);
 		return 0;
 	}
 
@@ -157,27 +157,27 @@ static uint8_t crb_activate_locality(void)
 }
 
 /* Switch Device into a Ready State */
-static int crb_switch_to_ready(void)
+static tpm_result_t crb_switch_to_ready(void)
 {
 	/* Transition into ready state */
 	write8(CRB_REG(cur_loc, CRB_REG_REQUEST), 0x1);
-	int rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_REQUEST), 200,
+	tpm_result_t rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_REQUEST), 200,
 					CRB_REG_REQUEST_CMD_RDY, 0x0);
 	if (rc) {
 		printk(BIOS_ERR,
-		       "TPM: Error - TPM did not transition into ready state in time.\n");
-		return -1;
+		       "TPM Error (%#x): TPM did not transition into ready state in time.\n", rc);
+		return rc;
 	}
 
 	/* Check TPM_CRB_CTRL_STS[0] to be "0" - no unrecoverable error */
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_STATUS), 500, CRB_REG_STATUS_ERROR,
 				0x0);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Fatal Error - Could not recover.\n");
-		return -1;
+		printk(BIOS_ERR, "TPM Error (%#x): Could not recover.\n", rc);
+		return rc;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -188,11 +188,12 @@ static int crb_switch_to_ready(void)
  * normal bring up mode.
  *
  */
-int tpm2_init(void)
+tpm_result_t tpm2_init(void)
 {
-	if (crb_probe()) {
+	tpm_result_t rc = crb_probe();
+	if (rc) {
 		printk(BIOS_ERR, "TPM: Probe failed.\n");
-		return -1;
+		return rc;
 	}
 
 	/* Read back control area structure */
@@ -211,7 +212,7 @@ int tpm2_init(void)
 	/* Good to go. */
 	printk(BIOS_SPEW, "TPM: CRB TPM initialized successfully\n");
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void set_ptt_cmd_resp_buffers(void)
@@ -231,7 +232,7 @@ static void set_ptt_cmd_resp_buffers(void)
 size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void *tpm2_response,
 			    size_t max_response)
 {
-	int rc;
+	tpm_result_t rc;
 
 	if (command_size > control_area.command_size) {
 		printk(BIOS_ERR, "TPM: Command size is too big.\n");
@@ -248,12 +249,15 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Check if CMD bit is cleared.
 	rc = crb_wait_for_reg32(CRB_REG(0, CRB_REG_START), 250, CRB_REG_START_START, 0x0);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - Cmd Bit not cleared.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Cmd Bit not cleared.\n", rc);
 		return -1;
 	}
 
-	if (crb_switch_to_ready())
+	rc = crb_switch_to_ready();
+	if (rc) {
+		printk(BIOS_DEBUG, "TPM Error (%#x): Can not transition into ready state.\n", rc);
 		return -1;
+	}
 
 	// Write to Command Buffer
 	memcpy(control_area.command_bfr, tpm2_command, command_size);
@@ -272,14 +276,14 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Poll for Response
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_START), 3500, CRB_REG_START_START, 0);
 	if (rc) {
-		printk(BIOS_DEBUG, "TPM: Command Timed out.\n");
+		printk(BIOS_DEBUG, "TPM Error (%#x): Command Timed out.\n", rc);
 		return -1;
 	}
 
 	// Check for errors
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_STATUS), 200, CRB_REG_STATUS_ERROR, 0);
 	if (rc) {
-		printk(BIOS_DEBUG, "TPM: Command errored.\n");
+		printk(BIOS_DEBUG, "TPM Error (%#x): Command errored.\n", rc);
 		return -1;
 	}
 
@@ -293,8 +297,9 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Copy Response
 	memcpy(tpm2_response, control_area.response_bfr, length);
 
-	if (crb_switch_to_ready()) {
-		printk(BIOS_DEBUG, "TPM: Can not transition into ready state again.\n");
+	rc = crb_switch_to_ready();
+	if (rc) {
+		printk(BIOS_DEBUG, "TPM Error (%#x): Can not transition into ready state again.\n", rc);
 		return -1;
 	}
 
diff --git a/src/drivers/crb/tpm.h b/src/drivers/crb/tpm.h
index be26be2d24..7b25e78b3b 100644
--- a/src/drivers/crb/tpm.h
+++ b/src/drivers/crb/tpm.h
@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: BSD-3-Clause */
 /* This is a driver for a Command Response Buffer Interface */
 
+#include <security/tpm/tss_errors.h>
+
 /* CRB driver */
 /* address of locality 0 (CRB) */
 #define TPM_CRB_BASE_ADDRESS        CONFIG_CRB_TPM_BASE_ADDRESS
@@ -58,7 +60,7 @@ struct tpm2_info {
 	uint16_t revision;
 };
 
-int tpm2_init(void);
+tpm_result_t tpm2_init(void);
 void tpm2_get_info(struct tpm2_info *tpm2_info);
 size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
 			    void *tpm2_response, size_t max_response);
diff --git a/src/drivers/i2c/tpm/cr50.c b/src/drivers/i2c/tpm/cr50.c
index 929628407d..d207f2b20b 100644
--- a/src/drivers/i2c/tpm/cr50.c
+++ b/src/drivers/i2c/tpm/cr50.c
@@ -56,12 +56,12 @@ static struct tpm_inf_dev tpm_dev;
  * 2) wait for TPM to indicate it is ready
  * 3) read 'len' bytes of TPM response into the provided 'buffer'
  *
- * Return -1 on error, 0 on success.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
+static tpm_result_t cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
 {
 	if (tpm_dev.addr == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Clear interrupt before starting transaction */
 	cr50_plat_irq_status();
@@ -69,20 +69,20 @@ static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
 	/* Send the register address byte to the TPM */
 	if (i2c_write_raw(tpm_dev.bus, tpm_dev.addr, &addr, 1)) {
 		printk(BIOS_ERR, "%s: Address write failed\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/* Wait for TPM to be ready with response data */
 	if (cr50_wait_tpm_ready() != CB_SUCCESS)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Read response data from the TPM */
 	if (i2c_read_raw(tpm_dev.bus, tpm_dev.addr, buffer, len)) {
 		printk(BIOS_ERR, "%s: Read response failed\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -96,14 +96,14 @@ static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
  * 2) send the address+data to the TPM
  * 3) wait for TPM to indicate it is done writing
  *
- * Returns -1 on error, 0 on success.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
+static tpm_result_t cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
 {
 	if (tpm_dev.addr == 0)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 	if (len > CR50_MAX_BUFSIZE)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 
 	/* Prepend the 'register address' to the buffer */
 	tpm_dev.buf[0] = addr;
@@ -115,11 +115,11 @@ static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
 	/* Send write request buffer with address */
 	if (i2c_write_raw(tpm_dev.bus, tpm_dev.addr, tpm_dev.buf, len + 1)) {
 		printk(BIOS_ERR, "%s: Error writing to TPM\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/* Wait for TPM to be ready */
-	return cr50_wait_tpm_ready() == CB_SUCCESS ? 0 : -1;
+	return cr50_wait_tpm_ready() == CB_SUCCESS ? TPM_SUCCESS : TPM_CB_FAIL;
 }
 
 /*
@@ -128,11 +128,13 @@ static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
  *
  * This function will make sure that the AP does not proceed with boot until
  * TPM finished reset processing.
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int process_reset(void)
+static tpm_result_t process_reset(void)
 {
 	struct stopwatch sw;
-	int rc = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 	uint8_t access;
 
 	/*
@@ -162,59 +164,72 @@ static int process_reset(void)
 		printk(BIOS_INFO, "TPM ready after %lld ms\n",
 		       stopwatch_duration_msecs(&sw));
 
-		return 0;
+		return TPM_SUCCESS;
 	} while (!stopwatch_expired(&sw));
 
-	if (rc)
-		printk(BIOS_ERR, "Failed to read TPM\n");
-	else
+	if (rc) {
+		printk(BIOS_ERR, "Failed to read TPM with error %d\n", rc);
+		return rc;
+	} else
 		printk(BIOS_ERR,
 			"TPM failed to reset after %lld ms, status: %#x\n",
 			stopwatch_duration_msecs(&sw), access);
-
-	return -1;
+	return TPM_CB_FAIL;
 }
 
 /*
  * Locality could be already claimed (if this is a later coreboot stage and
  * the RO did not release it), or not yet claimed, if this is verstage or the
  * older RO did release it.
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int claim_locality(void)
+static tpm_result_t claim_locality(void)
 {
 	uint8_t access;
 	const uint8_t mask = TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY;
+	tpm_result_t rc = TPM_SUCCESS;
 
-	if (cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access));
+	if (rc)
+		return rc;
 
 	if ((access & mask) == mask) {
 		printk(BIOS_INFO, "Locality already claimed\n");
-		return 0;
+		return TPM_SUCCESS;
 	}
 
 	access = TPM_ACCESS_REQUEST_USE;
-	if (cr50_i2c_write(TPM_ACCESS(0),
-			   &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_write(TPM_ACCESS(0),
+			   &access, sizeof(access));
+	if (rc)
+		return rc;
 
-	if (cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access));
+	if (rc)
+		return rc;
 
 	if ((access & mask) != mask) {
 		printk(BIOS_INFO, "Failed to claim locality.\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-/* cr50 requires all 4 bytes of status register to be read */
+/*
+ * cr50 requires all 4 bytes of status register to be read
+ *
+ * Returns lowest 8-bits of the TIS Status register value
+ * see tis_status bit mask enumerated type in tis.h.
+ * Return 0 on error.
+ */
 static uint8_t cr50_i2c_tis_status(void)
 {
 	uint8_t buf[4];
-	if (cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf)) < 0) {
-		printk(BIOS_ERR, "%s: Failed to read status\n", __func__);
+	tpm_result_t rc = cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf));
+	if (rc) {
+		printk(BIOS_ERR, "%s: Failed to read status with error %#x\n", __func__, rc);
 		return 0;
 	}
 	return buf[0];
@@ -229,16 +244,21 @@ static void cr50_i2c_tis_ready(void)
 }
 
 /* cr50 uses bytes 3:2 of status register for burst count and
- * all 4 bytes must be read */
-static int cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
+ * all 4 bytes must be read
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
+ */
+static tpm_result_t cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
 {
 	uint8_t buf[4];
 	struct stopwatch sw;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS);
 
 	while (!stopwatch_expired(&sw)) {
-		if (cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf)) != 0) {
+		rc = cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf));
+		if (rc) {
 			mdelay(CR50_TIMEOUT_SHORT_MS);
 			continue;
 		}
@@ -249,13 +269,14 @@ static int cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
 		/* Check if mask matches and burst is valid */
 		if ((*status & mask) == mask &&
 		    *burst > 0 && *burst <= CR50_MAX_BUFSIZE)
-			return 0;
+			return TPM_SUCCESS;
 
 		mdelay(CR50_TIMEOUT_SHORT_MS);
 	}
-
-	printk(BIOS_ERR, "%s: Timeout reading burst and status\n", __func__);
-	return -1;
+	printk(BIOS_ERR, "%s: Timeout reading burst and status with error %#x\n", __func__, rc);
+	if (rc)
+		return rc;
+	return TPM_CB_TIMEOUT;
 }
 
 static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
@@ -264,18 +285,21 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	uint8_t addr = TPM_DATA_FIFO(tpm_dev.locality);
 	uint8_t mask = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
 	int status;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (buf_len < TPM_HEADER_SIZE)
 		goto out_err;
 
-	if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0) {
-		printk(BIOS_ERR, "%s: First chunk not available\n", __func__);
+	rc = cr50_i2c_wait_burststs(mask, &burstcnt, &status);
+	if (rc) {
+		printk(BIOS_ERR, "%s: First chunk not available with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 
 	/* Read first chunk of burstcnt bytes */
-	if (cr50_i2c_read(addr, buf, burstcnt) != 0) {
-		printk(BIOS_ERR, "%s: Read failed\n", __func__);
+	rc = cr50_i2c_read(addr, buf, burstcnt);
+	if (rc) {
+		printk(BIOS_ERR, "%s: Read failed with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 
@@ -291,12 +315,13 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	current = burstcnt;
 	while (current < expected) {
 		/* Read updated burst count and check status */
-		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0)
+		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status))
 			goto out_err;
 
 		len = MIN(burstcnt, expected - current);
-		if (cr50_i2c_read(addr, buf + current, len) != 0) {
-			printk(BIOS_ERR, "%s: Read failed\n", __func__);
+		rc = cr50_i2c_read(addr, buf + current, len);
+		if (rc) {
+			printk(BIOS_ERR, "%s: Read failed with error %#x\n", __func__, rc);
 			goto out_err;
 		}
 
@@ -304,7 +329,7 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	}
 
 	/* Ensure TPM is done reading data */
-	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status) < 0)
+	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status))
 		goto out_err;
 	if (status & TPM_STS_DATA_AVAIL) {
 		printk(BIOS_ERR, "%s: Data still available\n", __func__);
@@ -326,6 +351,7 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	size_t burstcnt, limit, sent = 0;
 	uint8_t tpm_go[4] = { TPM_STS_GO };
 	struct stopwatch sw;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS);
 
@@ -348,14 +374,15 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 			mask |= TPM_STS_DATA_EXPECT;
 
 		/* Read burst count and check status */
-		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0)
+		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status))
 			goto out_err;
 
 		/* Use burstcnt - 1 to account for the address byte
 		 * that is inserted by cr50_i2c_write() */
 		limit = MIN(burstcnt - 1, len);
-		if (cr50_i2c_write(TPM_DATA_FIFO(tpm_dev.locality), &buf[sent], limit) != 0) {
-			printk(BIOS_ERR, "%s: Write failed\n", __func__);
+		rc = cr50_i2c_write(TPM_DATA_FIFO(tpm_dev.locality), &buf[sent], limit);
+		if (rc) {
+			printk(BIOS_ERR, "%s: Write failed with error %#x\n", __func__, rc);
 			goto out_err;
 		}
 
@@ -364,7 +391,7 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	}
 
 	/* Ensure TPM is not expecting more data */
-	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status) < 0)
+	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status))
 		goto out_err;
 	if (status & TPM_STS_DATA_EXPECT) {
 		printk(BIOS_ERR, "%s: Data still expected\n", __func__);
@@ -372,8 +399,9 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	}
 
 	/* Start the TPM command */
-	if (cr50_i2c_write(TPM_STS(tpm_dev.locality), tpm_go, sizeof(tpm_go)) < 0) {
-		printk(BIOS_ERR, "%s: Start command failed\n", __func__);
+	rc = cr50_i2c_write(TPM_STS(tpm_dev.locality), tpm_go, sizeof(tpm_go));
+	if (rc) {
+		printk(BIOS_ERR, "%s: Start command failed with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 	return sent;
@@ -396,14 +424,15 @@ static void cr50_vendor_init(struct tpm_chip *chip)
 	chip->cancel = &cr50_i2c_tis_ready;
 }
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr)
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-static int cr50_i2c_probe(uint32_t *did_vid)
+static tpm_result_t cr50_i2c_probe(uint32_t *did_vid)
 {
 	int retries;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/*
 	 * 1s should be enough to synchronize with the TPM even under the
@@ -414,14 +443,13 @@ static int cr50_i2c_probe(uint32_t *did_vid)
 	printk(BIOS_INFO, "Probing TPM I2C: ");
 
 	for (retries = 100; retries > 0; retries--) {
-		int rc;
 
 		rc = cr50_i2c_read(TPM_DID_VID(0), (uint8_t *)did_vid, 4);
 
 		/* Exit once DID and VID verified */
 		if (!rc && (*did_vid == CR50_DID_VID || *did_vid == TI50_DID_VID)) {
 			printk(BIOS_INFO, "done! DID_VID 0x%08x\n", *did_vid);
-			return 0;
+			return TPM_SUCCESS;
 		}
 
 		/* TPM might be resetting, let's retry in a bit. */
@@ -432,17 +460,21 @@ static int cr50_i2c_probe(uint32_t *did_vid)
 	/*
 	 * I2C reads failed, or the DID and VID didn't match
 	 */
-	printk(BIOS_ERR, "DID_VID 0x%08x not recognized\n", *did_vid);
-	return -1;
+	if (!rc) {
+		printk(BIOS_ERR, "DID_VID 0x%08x not recognized\n", *did_vid);
+		return TPM_CB_FAIL;
+	}
+	return rc;
 }
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 {
 	uint32_t did_vid = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (dev_addr == 0) {
 		printk(BIOS_ERR, "%s: missing device address\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	tpm_dev.bus = bus;
@@ -450,15 +482,19 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 
 	cr50_vendor_init(chip);
 
-	if (cr50_i2c_probe(&did_vid))
-		return -1;
+	rc = cr50_i2c_probe(&did_vid);
+	if (rc)
+		return rc;
 
-	if (ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK)
-		if (process_reset())
-			return -1;
+	if (ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK) {
+		rc = process_reset();
+		if (rc)
+			return rc;
+	}
 
-	if (claim_locality())
-		return -1;
+	rc = claim_locality();
+	if (rc)
+		return rc;
 
 	printk(BIOS_DEBUG, "cr50 TPM 2.0 (i2c %u:0x%02x id %#x)\n",
 	       bus, dev_addr, did_vid >> 16);
@@ -470,7 +506,7 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	}
 
 	chip->is_open = 1;
-	return 0;
+	return TPM_SUCCESS;
 }
 
 enum cb_err tis_vendor_write(unsigned int addr, const void *buffer, size_t bytes)
diff --git a/src/drivers/i2c/tpm/tis.c b/src/drivers/i2c/tpm/tis.c
index 25b7f40801..a5c3b8fdf3 100644
--- a/src/drivers/i2c/tpm/tis.c
+++ b/src/drivers/i2c/tpm/tis.c
@@ -19,27 +19,24 @@ static struct tpm_chip chip;
 #define TPM_CMD_COUNT_BYTE 2
 #define TPM_CMD_ORDINAL_BYTE 6
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
-	int rc;
+	tpm_result_t rc;
 
 	if (chip.is_open) {
 		printk(BIOS_DEBUG, "%s() called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	rc = tpm_vendor_init(&chip, CONFIG_DRIVER_TPM_I2C_BUS,
 			     CONFIG_DRIVER_TPM_I2C_ADDR);
-	if (rc < 0)
+	if (rc != TPM_SUCCESS)
 		chip.is_open = 0;
 
-	if (rc)
-		return -1;
-
-	return 0;
+	return rc;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	return tpm_vendor_probe(CONFIG_DRIVER_TPM_I2C_BUS,
 				CONFIG_DRIVER_TPM_I2C_ADDR);
@@ -48,23 +45,23 @@ int tis_init(void)
 static ssize_t tpm_transmit(const uint8_t *sbuf, size_t sbufsiz, void *rbuf,
 			size_t rbufsiz)
 {
-	int rc;
+	int rc = -1;
 	uint32_t count;
 
 	memcpy(&count, sbuf + TPM_CMD_COUNT_BYTE, sizeof(count));
 	count = be32_to_cpu(count);
 
 	if (!chip.send || !chip.status || !chip.cancel)
-		return -1;
+		goto out;
 
 	if (count == 0) {
 		printk(BIOS_DEBUG, "%s: no data\n", __func__);
-		return -1;
+		goto out;
 	}
 	if (count > sbufsiz) {
 		printk(BIOS_DEBUG, "%s: invalid count value %#x %zx\n", __func__,
 			count, sbufsiz);
-		return -1;
+		goto out;
 	}
 
 	ASSERT(chip.send);
@@ -95,11 +92,10 @@ static ssize_t tpm_transmit(const uint8_t *sbuf, size_t sbufsiz, void *rbuf,
 	ASSERT(chip.cancel);
 	chip.cancel();
 	printk(BIOS_DEBUG, "%s: Operation Timed out\n", __func__);
-	rc = -1; //ETIME;
+	rc = -1;
 	goto out;
 
 out_recv:
-
 	rc = chip.recv((uint8_t *)rbuf, rbufsiz);
 	if (rc < 0)
 		printk(BIOS_DEBUG, "%s: tpm_recv: error %d\n", __func__, rc);
@@ -107,7 +103,7 @@ out:
 	return rc;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		uint8_t *recvbuf, size_t *rbuf_len)
 {
 	ASSERT(sbuf_size >= 10);
@@ -124,12 +120,12 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 
 	if (len < 10) {
 		*rbuf_len = 0;
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if (len > *rbuf_len) {
 		*rbuf_len = len;
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	*rbuf_len = len;
@@ -142,5 +138,5 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		hexdump(recvbuf, *rbuf_len);
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/i2c/tpm/tis_atmel.c b/src/drivers/i2c/tpm/tis_atmel.c
index 669ac68f6c..91ed6a99e3 100644
--- a/src/drivers/i2c/tpm/tis_atmel.c
+++ b/src/drivers/i2c/tpm/tis_atmel.c
@@ -22,17 +22,17 @@ struct tpm_output_header {
 	uint32_t return_code;
 } __packed;
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		uint8_t *recvbuf, size_t *rbuf_len)
 {
 	size_t hdr_bytes;
@@ -60,8 +60,10 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 			sbuf_size);
 		if ((status < 0) && (!stopwatch_expired(&sw)))
 			continue;
-		if (status < 0)
-			return status;
+		if (status < 0) {
+			printk(BIOS_ERR, "I2C write error: %d\n", status);
+			return TPM_CB_COMMUNICATION_ERROR;
+		}
 		break;
 	}
 
@@ -79,7 +81,7 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		udelay(SLEEP_DURATION);
 	} while (!stopwatch_expired(&sw));
 	if (status != sizeof(*header))
-		return -1;
+		return TPM_CB_COMMUNICATION_ERROR;
 
 	/* Determine the number of bytes remaining */
 	recv_bytes = MIN(be32_to_cpu(*(uint32_t *)&header->length),
@@ -94,8 +96,10 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		/* Read the full TPM response */
 		status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
 			CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, recv_bytes);
-		if (status < 0)
-			return status;
+		if (status < 0) {
+			printk(BIOS_ERR, "I2C read error: %d\n", status);
+			return TPM_CB_COMMUNICATION_ERROR;
+		}
 	}
 
 	/* Return the number of bytes received */
@@ -110,5 +114,5 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 	}
 
 	/* Successful transfer */
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/i2c/tpm/tpm.c b/src/drivers/i2c/tpm/tpm.c
index c88dcdd4b9..4dbefb44f3 100644
--- a/src/drivers/i2c/tpm/tpm.c
+++ b/src/drivers/i2c/tpm/tpm.c
@@ -451,7 +451,7 @@ out_err:
 
 /* Initialization of I2C TPM */
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr)
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr)
 {
 	struct stopwatch sw;
 	uint8_t buf = 0;
@@ -487,18 +487,18 @@ int tpm_vendor_probe(unsigned int bus, uint32_t addr)
 	 * Claim failure if the ValidSts (bit 7) is clear.
 	 */
 	if (!(buf & TPM_STS_VALID))
-		return -1;
+		return TPM_CB_FAIL;
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 {
 	uint32_t vendor;
 
 	if (dev_addr == 0) {
 		printk(BIOS_ERR, "%s: missing device address\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	tpm_dev.chip_type = UNKNOWN;
@@ -518,7 +518,7 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	chip->cancel = &tpm_tis_i2c_ready;
 
 	if (request_locality(0) != 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Read four bytes from DID_VID register */
 	if (iic_tpm_read(TPM_DID_VID(0), (uint8_t *)&vendor, 4) < 0)
@@ -543,9 +543,9 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	 * Standard timeout values are used so far
 	 */
 
-	return 0;
+	return TPM_SUCCESS;
 
 out_err:
 	release_locality(0, 1);
-	return -1;
+	return TPM_CB_FAIL;
 }
diff --git a/src/drivers/i2c/tpm/tpm.h b/src/drivers/i2c/tpm/tpm.h
index d4176cc511..fb9837789d 100644
--- a/src/drivers/i2c/tpm/tpm.h
+++ b/src/drivers/i2c/tpm/tpm.h
@@ -12,6 +12,7 @@
 #ifndef __DRIVERS_TPM_SLB9635_I2C_TPM_H__
 #define __DRIVERS_TPM_SLB9635_I2C_TPM_H__
 
+#include <security/tpm/tss_errors.h>
 #include <stdint.h>
 
 enum tpm_timeout {
@@ -51,8 +52,8 @@ struct tpm_chip {
 
 /* ---------- Interface for TPM vendor ------------ */
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr);
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr);
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr);
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr);
 
 #endif /* __DRIVERS_TPM_SLB9635_I2C_TPM_H__ */
diff --git a/src/drivers/pc80/tpm/tis.c b/src/drivers/pc80/tpm/tis.c
index a7a3e9d72d..3f2d6bd7a2 100644
--- a/src/drivers/pc80/tpm/tis.c
+++ b/src/drivers/pc80/tpm/tis.c
@@ -74,17 +74,6 @@
 #define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
 #define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */
 
-/*
- * Error value returned if a tpm register does not enter the expected state
- * after continuous polling. No actual TPM register reading ever returns ~0,
- * so this value is a safe error indication to be mixed with possible status
- * register values.
- */
-#define TPM_TIMEOUT_ERR			(~0)
-
-/* Error value returned on various TPM driver errors */
-#define TPM_DRIVER_ERR		(~0)
-
  /* 1 second is plenty for anything TPM does.*/
 #define MAX_DELAY_US	USECS_PER_SEC
 
@@ -248,9 +237,9 @@ static inline u32 tpm_read_int_polarity(int locality)
  * @mask - bitmask for the bitfield(s) to watch
  * @expected - value the field(s) are supposed to be set to
  *
- * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
+ * Returns TPM_SUCCESS on success or TPM_CB_TIMEOUT on timeout.
  */
-static int tis_wait_sts(int locality, u8 mask, u8 expected)
+static tpm_result_t tis_wait_sts(int locality, u8 mask, u8 expected)
 {
 	struct stopwatch sw;
 
@@ -258,24 +247,24 @@ static int tis_wait_sts(int locality, u8 mask, u8 expected)
 	do {
 		u8 value = tpm_read_status(locality);
 		if ((value & mask) == expected)
-			return 0;
+			return TPM_SUCCESS;
 		udelay(1);
 	} while (!stopwatch_expired(&sw));
-	return TPM_TIMEOUT_ERR;
+	return TPM_CB_TIMEOUT;
 }
 
-static inline int tis_wait_ready(int locality)
+static inline tpm_result_t tis_wait_ready(int locality)
 {
 	return tis_wait_sts(locality, TIS_STS_COMMAND_READY,
 	                    TIS_STS_COMMAND_READY);
 }
 
-static inline int tis_wait_valid(int locality)
+static inline tpm_result_t tis_wait_valid(int locality)
 {
 	return tis_wait_sts(locality, TIS_STS_VALID, TIS_STS_VALID);
 }
 
-static inline int tis_wait_valid_data(int locality)
+static inline tpm_result_t tis_wait_valid_data(int locality)
 {
 	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
 	return tis_wait_sts(locality, has_data, has_data);
@@ -302,9 +291,9 @@ static inline int tis_expect_data(int locality)
  * @mask - bitmask for the bitfield(s) to watch
  * @expected - value the field(s) are supposed to be set to
  *
- * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
+ * Returns TPM_SUCCESS on success or TPM_CB_TIMEOUT on timeout.
  */
-static int tis_wait_access(int locality, u8 mask, u8 expected)
+static tpm_result_t tis_wait_access(int locality, u8 mask, u8 expected)
 {
 	struct stopwatch sw;
 
@@ -312,13 +301,13 @@ static int tis_wait_access(int locality, u8 mask, u8 expected)
 	do {
 		u8 value = tpm_read_access(locality);
 		if ((value & mask) == expected)
-			return 0;
+			return TPM_SUCCESS;
 		udelay(1);
 	} while (!stopwatch_expired(&sw));
-	return TPM_TIMEOUT_ERR;
+	return TPM_CB_TIMEOUT;
 }
 
-static inline int tis_wait_received_access(int locality)
+static inline tpm_result_t tis_wait_received_access(int locality)
 {
 	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY,
 	                       TIS_ACCESS_ACTIVE_LOCALITY);
@@ -345,10 +334,8 @@ static inline void tis_request_access(int locality)
  * In practice not all TPMs behave the same so it is necessary to be
  * flexible when trying to set command ready.
  *
- * Returns 0 on success if the TPM is ready for transactions.
- * Returns TPM_TIMEOUT_ERR if the command ready bit does not get set.
  */
-static int tis_command_ready(u8 locality)
+static tpm_result_t tis_command_ready(u8 locality)
 {
 	u32 status;
 
@@ -360,7 +347,7 @@ static int tis_command_ready(u8 locality)
 
 	/* Check if command ready is set yet */
 	if (status & TIS_STS_COMMAND_READY)
-		return 0;
+		return TPM_SUCCESS;
 
 	/* 2nd attempt to set command ready */
 	tpm_write_status(TIS_STS_COMMAND_READY, locality);
@@ -373,10 +360,10 @@ static int tis_command_ready(u8 locality)
  *
  * Probe the TPM device and try determining its manufacturer/device name.
  *
- * Returns 0 on success (the device is found or was found during an earlier
- * invocation) or TPM_DRIVER_ERR if the device is not found.
+ * Returns TPM_SUCCESS on success (the device is found or was found during
+ * an earlier invocation) or TPM_CB_FAIL if the device is not found.
  */
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	const char *device_name = "unknown";
 	const char *vendor_name = device_name;
@@ -386,12 +373,12 @@ int tis_init(void)
 	int i;
 
 	if (vendor_dev_id)
-		return 0;  /* Already probed. */
+		return TPM_SUCCESS;  /* Already probed. */
 
 	didvid = tpm_read_did_vid(0);
 	if (!didvid || (didvid == 0xffffffff)) {
 		printf("%s: No TPM device found\n", __func__);
-		return TPM_DRIVER_ERR;
+		return TPM_CB_FAIL;
 	}
 
 	vendor_dev_id = didvid;
@@ -419,7 +406,7 @@ int tis_init(void)
 	}
 	/* this will have to be converted into debug printout */
 	printk(BIOS_INFO, "Found TPM %s by %s\n", device_name, vendor_name);
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -430,19 +417,21 @@ int tis_init(void)
  * @data - address of the data to send, byte by byte
  * @len - length of the data to send
  *
- * Returns 0 on success, TPM_DRIVER_ERR on error (in case the device does
+ * Returns TPM_SUCCESS on success, TPM_CB_FAIL on error (in case the device does
  * not accept the entire command).
  */
-static u32 tis_senddata(const u8 *const data, u32 len)
+static tpm_result_t tis_senddata(const u8 *const data, u32 len)
 {
 	u32 offset = 0;
 	u16 burst = 0;
 	u8 locality = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
-	if (tis_wait_ready(locality)) {
-		printf("%s:%d - failed to get 'command_ready' status\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_ready(locality);
+	if (rc) {
+		printf("%s:%d - failed to get 'command_ready' status with error %#x\n",
+		       __FILE__, __LINE__, rc);
+		return rc;
 	}
 	burst = tpm_read_burst_count(locality);
 
@@ -456,7 +445,7 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 			if (stopwatch_expired(&sw)) {
 				printf("%s:%d failed to feed %u bytes of %u\n",
 				       __FILE__, __LINE__, len - offset, len);
-				return TPM_DRIVER_ERR;
+				return TPM_CB_TIMEOUT;
 			}
 			udelay(1);
 			burst = tpm_read_burst_count(locality);
@@ -475,10 +464,11 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 		while (count--)
 			tpm_write_data(data[offset++], locality);
 
-		if (tis_wait_valid(locality) || !tis_expect_data(locality)) {
-			printf("%s:%d TPM command feed overflow\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_valid(locality);
+		if (rc || !tis_expect_data(locality)) {
+			printf("%s:%d TPM command feed overflow with error %#x\n",
+			       __FILE__, __LINE__, rc);
+			return rc ? rc : TPM_CB_FAIL;
 		}
 
 		burst = tpm_read_burst_count(locality);
@@ -498,16 +488,17 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 	 * Verify that TPM does not expect any more data as part of this
 	 * command.
 	 */
-	if (tis_wait_valid(locality) || tis_expect_data(locality)) {
-		printf("%s:%d unexpected TPM status %#x\n",
-		       __FILE__, __LINE__, tpm_read_status(locality));
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_valid(locality);
+	if (rc || tis_expect_data(locality)) {
+		printf("%s:%d unexpected TPM error %#x with status %#x\n",
+		       __FILE__, __LINE__, rc, tpm_read_status(locality));
+		return rc ? rc : TPM_CB_FAIL;
 	}
 
 	/* OK, sitting pretty, let's start the command execution. */
 	tpm_write_status(TIS_STS_TPM_GO, locality);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -518,22 +509,25 @@ static u32 tis_senddata(const u8 *const data, u32 len)
  * @buffer - address where to read the response, byte by byte.
  * @len - pointer to the size of buffer
  *
- * On success stores the number of received bytes to len and returns 0. On
- * errors (misformatted TPM data or synchronization problems) returns
- * TPM_DRIVER_ERR.
+ * On success stores the number of received bytes to len and returns
+ * TPM_SUCCESS. On errors (misformatted TPM data or synchronization
+ * problems) returns TPM_CB_FAIL.
  */
-static u32 tis_readresponse(u8 *buffer, size_t *len)
+static tpm_result_t tis_readresponse(u8 *buffer, size_t *len)
 {
 	u16 burst_count;
 	u32 offset = 0;
 	u8 locality = 0;
 	u32 expected_count = *len;
 	int max_cycles = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Wait for the TPM to process the command */
-	if (tis_wait_valid_data(locality)) {
-		printf("%s:%d failed processing command\n", __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_valid_data(locality);
+	if (rc) {
+		printf("%s:%d failed processing command with error %#x\n",
+			   __FILE__, __LINE__, rc);
+		return rc;
 	}
 
 	do {
@@ -541,7 +535,7 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 			if (max_cycles++ == MAX_DELAY_US) {
 				printf("%s:%d TPM stuck on read\n",
 				       __FILE__, __LINE__);
-				return TPM_DRIVER_ERR;
+				return TPM_CB_FAIL;
 			}
 			udelay(1);
 		}
@@ -569,16 +563,17 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 					printf("%s:%d bad response size %u\n",
 					       __FILE__, __LINE__,
 					       expected_count);
-					return TPM_DRIVER_ERR;
+					return TPM_CB_FAIL;
 				}
 			}
 		}
 
 		/* Wait for the next portion */
-		if (tis_wait_valid(locality)) {
-			printf("%s:%d failed to read response\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_valid(locality);
+		if (rc) {
+			printf("%s:%d failed to read response with error %#x\n",
+			       __FILE__, __LINE__, rc);
+			return rc;
 		}
 
 		if (offset == expected_count)
@@ -599,15 +594,16 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 		printf("%s:%d wrong receive status: %#x %u bytes left\n",
 		       __FILE__, __LINE__, tpm_read_status(locality),
 	               tpm_read_burst_count(locality));
-		return TPM_DRIVER_ERR;
+		return TPM_CB_FAIL;
 	}
 
 	/* Tell the TPM that we are done. */
-	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
-		return TPM_DRIVER_ERR;
+	rc = tis_command_ready(locality);
+	if (rc)
+		return rc;
 
 	*len = offset;
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -615,31 +611,30 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
  *
  * Requests access to locality 0 for the caller.
  *
- * Returns 0 on success, TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success, TSS Error on failure.
  */
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	u8 locality = 0; /* we use locality zero for everything */
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (!tis_has_access(locality)) {
 		/* request access to locality */
 		tis_request_access(locality);
 
 		/* did we get a lock? */
-		if (tis_wait_received_access(locality)) {
-			printf("%s:%d - failed to lock locality %u\n",
-			__FILE__, __LINE__, locality);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_received_access(locality);
+		if (rc) {
+			printf("%s:%d - failed to lock locality %u with error %#x\n",
+			__FILE__, __LINE__, locality, rc);
+			return rc;
 		}
 
 		/* Certain TPMs seem to need some delay here or they hang... */
 		udelay(10);
 	}
 
-	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
-		return TPM_DRIVER_ERR;
-
-	return 0;
+	return tis_command_ready(locality);
 }
 
 /*
@@ -652,16 +647,17 @@ int tis_open(void)
  * @recvbuf - memory to save the response to
  * @recv_len - pointer to the size of the response buffer
  *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success (and places the number of response bytes
+ * at recv_len) or TPM_CB_FAIL on failure.
  */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
 		 uint8_t *recvbuf, size_t *recv_len)
 {
-	if (tis_senddata(sendbuf, send_size)) {
-		printf("%s:%d failed sending data to TPM\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	tpm_result_t rc = tis_senddata(sendbuf, send_size);
+	if (rc) {
+		printf("%s:%d failed sending data to TPM with error %#x\n",
+		       __FILE__, __LINE__, rc);
+		return rc;
 	}
 
 	return tis_readresponse(recvbuf, recv_len);
@@ -680,14 +676,15 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
  * @vector - TPM interrupt vector
  * @polarity - TPM interrupt polarity
  *
- * Returns 0 on success, TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success, TPM_CB_FAIL on failure.
  */
-static int tis_setup_interrupt(int vector, int polarity)
+static tpm_result_t tis_setup_interrupt(int vector, int polarity)
 {
 	u8 locality = 0;
+	tpm_result_t rc = tlcl_lib_init();
 
-	if (tlcl_lib_init())
-		return TPM_DRIVER_ERR;
+	if (rc)
+		return rc;
 
 	/* Set TPM interrupt vector */
 	tpm_write_int_vector(vector, locality);
@@ -695,7 +692,7 @@ static int tis_setup_interrupt(int vector, int polarity)
 	/* Set TPM interrupt polarity and disable interrupts */
 	tpm_write_int_polarity(polarity, locality);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void lpc_tpm_read_resources(struct device *dev)
diff --git a/src/drivers/spi/tpm/tis.c b/src/drivers/spi/tpm/tis.c
index b9b2a4a5cb..6fa6c82848 100644
--- a/src/drivers/spi/tpm/tis.c
+++ b/src/drivers/spi/tpm/tis.c
@@ -29,29 +29,31 @@ static const char *tis_get_dev_name(struct tpm2_info *info)
 	return "Unknown";
 }
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	if (tpm_is_open) {
 		printk(BIOS_ERR, "%s() called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	struct spi_slave spi;
 	struct tpm2_info info;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (spi_setup_slave(CONFIG_DRIVER_TPM_SPI_BUS,
 			    CONFIG_DRIVER_TPM_SPI_CHIP, &spi)) {
 		printk(BIOS_ERR, "Failed to setup TPM SPI slave\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	if (tpm2_init(&spi)) {
+	rc = tpm2_init(&spi);
+	if (rc) {
 		printk(BIOS_ERR, "Failed to initialize TPM SPI interface\n");
-		return -1;
+		return rc;
 	}
 
 	tpm2_get_info(&info);
@@ -59,18 +61,18 @@ int tis_init(void)
 	printk(BIOS_INFO, "Initialized TPM device %s revision %d\n",
 	       tis_get_dev_name(&info), info.revision);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		 uint8_t *recvbuf, size_t *rbuf_len)
 {
 	int len = tpm2_process_command(sendbuf, sbuf_size, recvbuf, *rbuf_len);
 
 	if (len == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	*rbuf_len = len;
 
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c
index 01f04f4a36..13f44f9448 100644
--- a/src/drivers/spi/tpm/tpm.c
+++ b/src/drivers/spi/tpm/tpm.c
@@ -394,7 +394,7 @@ static const uint32_t supported_did_vids[] = {
 	0x0000104a   /* ST33HTPH2E32 */
 };
 
-int tpm2_init(struct spi_slave *spi_if)
+tpm_result_t tpm2_init(struct spi_slave *spi_if)
 {
 	uint32_t did_vid, status, intf_id;
 	uint8_t cmd;
@@ -433,7 +433,7 @@ int tpm2_init(struct spi_slave *spi_if)
 	if (!retries) {
 		printk(BIOS_ERR, "\n%s: Failed to connect to the TPM\n",
 		       __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	printk(BIOS_INFO, " done!\n");
@@ -444,11 +444,11 @@ int tpm2_init(struct spi_slave *spi_if)
 		if (tpm2_read_reg(TPM_INTF_ID_REG, &intf_id, sizeof(intf_id)) != CB_SUCCESS) {
 			printk(BIOS_ERR, "\n%s: Failed to read interface ID register\n",
 			       __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 		if ((be32toh(intf_id) & 0xF) == 0xF) {
 			printk(BIOS_DEBUG, "\n%s: Not a TPM2 device\n", __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 	}
 
@@ -459,16 +459,16 @@ int tpm2_init(struct spi_slave *spi_if)
 		 * initialization after reset.
 		 */
 		if (tpm2_claim_locality() != CB_SUCCESS)
-			return -1;
+			return TPM_CB_FAIL;
 
 	if (read_tpm_sts(&status) != CB_SUCCESS) {
 		printk(BIOS_ERR, "Reading status reg failed\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 	if ((status & TPM_STS_FAMILY_MASK) != TPM_STS_FAMILY_TPM_2_0) {
 		printk(BIOS_ERR, "unexpected TPM family value, status: %#x\n",
 		       status);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/*
@@ -492,7 +492,7 @@ int tpm2_init(struct spi_slave *spi_if)
                         cr50_set_board_cfg();
 		}
 	}
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
diff --git a/src/drivers/spi/tpm/tpm.h b/src/drivers/spi/tpm/tpm.h
index cb09148b1f..da15a73bd8 100644
--- a/src/drivers/spi/tpm/tpm.h
+++ b/src/drivers/spi/tpm/tpm.h
@@ -4,6 +4,7 @@
 #define __COREBOOT_SRC_DRIVERS_SPI_TPM_TPM_H
 
 #include <drivers/tpm/cr50.h>
+#include <security/tpm/tss_errors.h>
 #include <stddef.h>
 #include <spi-generic.h>
 
@@ -26,7 +27,7 @@ struct tpm2_info {
  *
  * Return 0 on success, non-zero on failure.
  */
-int tpm2_init(struct spi_slave *spi_if);
+tpm_result_t tpm2_init(struct spi_slave *spi_if);
 
 /*
  * Each command processing consists of sending the command to the TPM, by
diff --git a/src/mainboard/facebook/fbg1701/romstage.c b/src/mainboard/facebook/fbg1701/romstage.c
index 41ae099d88..a7405e9b53 100644
--- a/src/mainboard/facebook/fbg1701/romstage.c
+++ b/src/mainboard/facebook/fbg1701/romstage.c
@@ -7,6 +7,7 @@
 #if CONFIG(VENDORCODE_ELTAN_MBOOT)
 #include <mboot.h>
 #endif
+#include <security/tpm/tss_errors.h>
 #include <soc/lpc.h>
 #include <soc/pci_devs.h>
 #include <soc/romstage.h>
@@ -71,9 +72,9 @@ static const uint8_t crtm_version[] =
 	CONFIG_VENDORCODE_ELTAN_CRTM_VERSION_STRING COREBOOT_VERSION COREBOOT_EXTRA_VERSION
 	" " COREBOOT_BUILD;
 
-int mb_crtm(void)
+tpm_result_t mb_crtm(void)
 {
-	int rc = TPM_IOERROR;
+	tpm_result_t rc = TPM_IOERROR;
 	TCG_PCR_EVENT2_HDR tcgEventHdr;
 
 	/* Use FirmwareVersion string to represent CRTM version. */
diff --git a/src/mainboard/google/brya/mainboard.c b/src/mainboard/google/brya/mainboard.c
index 638d40254f..aa332cd806 100644
--- a/src/mainboard/google/brya/mainboard.c
+++ b/src/mainboard/google/brya/mainboard.c
@@ -34,10 +34,10 @@ static void mainboard_smbios_strings(struct device *dev, struct smbios_type11 *t
 
 void mainboard_update_soc_chip_config(struct soc_intel_alderlake_config *config)
 {
-	int rc;
+	tpm_result_t rc;
 
 	rc = tlcl_lib_init();
-	if (rc != VB2_SUCCESS) {
+	if (rc != TPM_SUCCESS) {
 		printk(BIOS_ERR, "tlcl_lib_init() failed: %#x\n", rc);
 		return;
 	}
diff --git a/src/mainboard/google/dedede/mainboard.c b/src/mainboard/google/dedede/mainboard.c
index 3abee01caa..a0a537c4cb 100644
--- a/src/mainboard/google/dedede/mainboard.c
+++ b/src/mainboard/google/dedede/mainboard.c
@@ -14,10 +14,10 @@
 static void mainboard_update_soc_chip_config(void)
 {
 	struct soc_intel_jasperlake_config *cfg = config_of_soc();
-	int rc;
+	tpm_result_t rc;
 
 	rc = tlcl_lib_init();
-	if (rc != VB2_SUCCESS) {
+	if (rc != TPM_SUCCESS) {
 		printk(BIOS_ERR, "tlcl_lib_init() failed: %#x\n", rc);
 		return;
 	}
diff --git a/src/mainboard/google/volteer/mainboard.c b/src/mainboard/google/volteer/mainboard.c
index 4dc97c3637..fba96644e5 100644
--- a/src/mainboard/google/volteer/mainboard.c
+++ b/src/mainboard/google/volteer/mainboard.c
@@ -82,7 +82,7 @@ static void mainboard_enable(struct device *dev)
 
 void mainboard_update_soc_chip_config(struct soc_intel_tigerlake_config *cfg)
 {
-	int rc;
+	tpm_result_t rc;
 	if (!CONFIG(TPM_GOOGLE_CR50) || !CONFIG(SPI_TPM)) {
 		/*
 		 * Negotiation of long interrupt pulses is only supported via SPI.  I2C is only
@@ -94,7 +94,7 @@ void mainboard_update_soc_chip_config(struct soc_intel_tigerlake_config *cfg)
 	}
 
 	rc = tlcl_lib_init();
-	if (rc != VB2_SUCCESS) {
+	if (rc != TPM_SUCCESS) {
 		printk(BIOS_ERR, "tlcl_lib_init() failed: %#x\n", rc);
 		return;
 	}
diff --git a/src/security/intel/txt/txt_register.h b/src/security/intel/txt/txt_register.h
index 95f2a680d9..a00084511f 100644
--- a/src/security/intel/txt/txt_register.h
+++ b/src/security/intel/txt/txt_register.h
@@ -109,9 +109,9 @@
  * Note: Only locality 0 registers are publicly accessible.
  */
 
-#define TPM_BASE	0xfed40000UL
+#define TPM_BASE_ADDR	0xfed40000UL
 
-#define TPM_ACCESS_REG	(TPM_BASE + 0x00)
+#define TPM_ACCESS_REG	(TPM_BASE_ADDR + 0x00)
 
 /*
  * TXT Memory regions
diff --git a/src/security/tpm/tis.h b/src/security/tpm/tis.h
index fae049efff..34dc8e8bd7 100644
--- a/src/security/tpm/tis.h
+++ b/src/security/tpm/tis.h
@@ -3,6 +3,7 @@
 #ifndef TIS_H_
 #define TIS_H_
 
+#include <security/tpm/tss_errors.h>
 #include <types.h>
 
 enum tis_access {
@@ -34,19 +35,19 @@ enum tis_status {
 /*
  * tis_init()
  *
- * Initialize the TPM device. Returns 0 on success or -1 on
- * failure (in case device probing did not succeed).
+ * Initialize the TPM device.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-int tis_init(void);
+tpm_result_t tis_init(void);
 
 /*
  * tis_open()
  *
  * Requests access to locality 0 for the caller.
  *
- * Returns 0 on success, -1 on failure.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-int tis_open(void);
+tpm_result_t tis_open(void);
 
 /*
  * tis_sendrecv()
@@ -58,10 +59,9 @@ int tis_open(void);
  * @recvbuf - memory to save the response to
  * @recv_len - pointer to the size of the response buffer
  *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or -1 on failure.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-int tis_sendrecv(const u8 *sendbuf, size_t send_size, u8 *recvbuf,
+tpm_result_t tis_sendrecv(const u8 *sendbuf, size_t send_size, u8 *recvbuf,
 			size_t *recv_len);
 
 /*
diff --git a/src/security/tpm/tspi.h b/src/security/tpm/tspi.h
index 33f363cab6..3e7e5f10f5 100644
--- a/src/security/tpm/tspi.h
+++ b/src/security/tpm/tspi.h
@@ -137,22 +137,22 @@ static inline void tpm_log_dump(void *unused)
  * @param name sets additional info where the digest comes from
  * @return TPM_SUCCESS on success. If not a tpm error is returned
  */
-uint32_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
-			const uint8_t *digest, size_t digest_len,
-			const char *name);
+tpm_result_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
+			    const uint8_t *digest, size_t digest_len,
+			    const char *name);
 
 /**
  * Issue a TPM_Clear and re-enable/reactivate the TPM.
  * @return TPM_SUCCESS on success. If not a tpm error is returned
  */
-uint32_t tpm_clear_and_reenable(void);
+tpm_result_t tpm_clear_and_reenable(void);
 
 /**
  * Start the TPM and establish the root of trust.
  * @param s3flag tells the tpm setup if we wake up from a s3 state on x86
  * @return TPM_SUCCESS on success. If not a tpm error is returned
  */
-uint32_t tpm_setup(int s3flag);
+tpm_result_t tpm_setup(int s3flag);
 
 /**
  * Measure a given region device and extend given PCR with the result.
@@ -161,7 +161,7 @@ uint32_t tpm_setup(int s3flag);
  * @param *rname Name of the region that is measured
  * @return TPM error code in case of error otherwise TPM_SUCCESS
  */
-uint32_t tpm_measure_region(const struct region_device *rdev, uint8_t pcr,
-			    const char *rname);
+tpm_result_t tpm_measure_region(const struct region_device *rdev, uint8_t pcr,
+				const char *rname);
 
 #endif /* TSPI_H_ */
diff --git a/src/security/tpm/tspi/crtm.c b/src/security/tpm/tspi/crtm.c
index 4f29ad134b..4a89d7f262 100644
--- a/src/security/tpm/tspi/crtm.c
+++ b/src/security/tpm/tspi/crtm.c
@@ -31,25 +31,27 @@ static inline int tpm_log_available(void)
  *    stage.
  *
  * Takes the current vboot context as parameter for s3 checks.
- * returns on success VB2_SUCCESS, else a vboot error.
+ * returns on success TPM_SUCCESS, else a TPM error.
  */
-static uint32_t tspi_init_crtm(void)
+static tpm_result_t tspi_init_crtm(void)
 {
+	tpm_result_t rc = TPM_SUCCESS;
 	/* Initialize TPM PRERAM log. */
 	if (!tpm_log_available()) {
 		tpm_preram_log_clear();
 		tpm_log_initialized = 1;
 	} else {
 		printk(BIOS_WARNING, "TSPI: CRTM already initialized!\n");
-		return VB2_SUCCESS;
+		return TPM_SUCCESS;
 	}
 
 	struct region_device fmap;
 	if (fmap_locate_area_as_rdev("FMAP", &fmap) == 0) {
-		if (tpm_measure_region(&fmap, CONFIG_PCR_SRTM, "FMAP: FMAP")) {
+		rc = tpm_measure_region(&fmap, CONFIG_PCR_SRTM, "FMAP: FMAP");
+		if (rc) {
 			printk(BIOS_ERR,
-			       "TSPI: Couldn't measure FMAP into CRTM!\n");
-			return VB2_ERROR_UNKNOWN;
+			       "TSPI: Couldn't measure FMAP into CRTM! rc %#x\n", rc);
+			return rc;
 		}
 	} else {
 		printk(BIOS_ERR, "TSPI: Could not find FMAP!\n");
@@ -59,10 +61,11 @@ static uint32_t tspi_init_crtm(void)
 	if (!CONFIG(ARCH_X86)) {
 		struct region_device bootblock_fmap;
 		if (fmap_locate_area_as_rdev("BOOTBLOCK", &bootblock_fmap) == 0) {
-			if (tpm_measure_region(&bootblock_fmap,
+			rc = tpm_measure_region(&bootblock_fmap,
 					CONFIG_PCR_SRTM,
-					"FMAP: BOOTBLOCK"))
-				return VB2_ERROR_UNKNOWN;
+					"FMAP: BOOTBLOCK");
+			if (rc)
+				return rc;
 		}
 	} else if (CONFIG(BOOTBLOCK_IN_CBFS)){
 		/* Mapping measures the file. We know we can safely map here because
@@ -72,7 +75,7 @@ static uint32_t tspi_init_crtm(void)
 		if (!mapping) {
 			printk(BIOS_INFO,
 			       "TSPI: Couldn't measure bootblock into CRTM!\n");
-			return VB2_ERROR_UNKNOWN;
+			return TPM_CB_FAIL;
 		}
 		cbfs_unmap(mapping);
 	} else {
@@ -82,11 +85,11 @@ static uint32_t tspi_init_crtm(void)
 		if (tspi_soc_measure_bootblock(CONFIG_PCR_SRTM)) {
 			printk(BIOS_INFO,
 			       "TSPI: Couldn't measure bootblock into CRTM on SoC level!\n");
-			return VB2_ERROR_UNKNOWN;
+			return TPM_CB_FAIL;
 		}
 	}
 
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
 static bool is_runtime_data(const char *name)
@@ -108,16 +111,18 @@ static bool is_runtime_data(const char *name)
 	return !strcmp(allowlist, name);
 }
 
-uint32_t tspi_cbfs_measurement(const char *name, uint32_t type, const struct vb2_hash *hash)
+tpm_result_t tspi_cbfs_measurement(const char *name, uint32_t type, const struct vb2_hash *hash)
 {
 	uint32_t pcr_index;
+	tpm_result_t rc = TPM_SUCCESS;
 	char tpm_log_metadata[TPM_CB_LOG_PCR_HASH_NAME];
 
 	if (!tpm_log_available()) {
-		if (tspi_init_crtm() != VB2_SUCCESS) {
+		rc = tspi_init_crtm();
+		if (rc) {
 			printk(BIOS_WARNING,
 			       "Initializing CRTM failed!\n");
-			return 0;
+			return rc;
 		}
 		printk(BIOS_DEBUG, "CRTM initialized.\n");
 	}
@@ -171,7 +176,7 @@ void *tpm_log_init(void)
 	return tclt;
 }
 
-int tspi_measure_cache_to_pcr(void)
+tpm_result_t tspi_measure_cache_to_pcr(void)
 {
 	int i;
 	int pcr;
@@ -181,27 +186,27 @@ int tspi_measure_cache_to_pcr(void)
 
 	/* This means the table is empty. */
 	if (!tpm_log_available())
-		return VB2_SUCCESS;
+		return TPM_SUCCESS;
 
 	if (tpm_log_init() == NULL) {
 		printk(BIOS_WARNING, "TPM LOG: log non-existent!\n");
-		return VB2_ERROR_UNKNOWN;
+		return TPM_CB_FAIL;
 	}
 
 	printk(BIOS_DEBUG, "TPM: Write digests cached in TPM log to PCR\n");
 	i = 0;
 	while (!tpm_log_get(i++, &pcr, &digest_data, &digest_algo, &event_name)) {
 		printk(BIOS_DEBUG, "TPM: Write digest for %s into PCR %d\n", event_name, pcr);
-		int rc = tlcl_extend(pcr, digest_data, digest_algo);
+		tpm_result_t rc = tlcl_extend(pcr, digest_data, digest_algo);
 		if (rc != TPM_SUCCESS) {
 			printk(BIOS_ERR,
 			       "TPM: Writing digest of %s into PCR failed with error %d\n",
 				event_name, rc);
-			return VB2_ERROR_UNKNOWN;
+			return rc;
 		}
 	}
 
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
 #if !CONFIG(VBOOT_RETURN_FROM_VERSTAGE)
diff --git a/src/security/tpm/tspi/crtm.h b/src/security/tpm/tspi/crtm.h
index 2bc1d1fad9..6f5eb2e716 100644
--- a/src/security/tpm/tspi/crtm.h
+++ b/src/security/tpm/tspi/crtm.h
@@ -5,6 +5,7 @@
 
 #include <program_loading.h>
 #include <security/tpm/tspi.h>
+#include <security/tpm/tss_errors.h>
 #include <types.h>
 #include <vb2_sha.h>
 
@@ -40,12 +41,12 @@
 /**
  * Measure digests cached in TPM log entries into PCRs
  */
-int tspi_measure_cache_to_pcr(void);
+tpm_result_t tspi_measure_cache_to_pcr(void);
 
 /**
  * Extend a measurement hash taken for a CBFS file into the appropriate PCR.
  */
-uint32_t tspi_cbfs_measurement(const char *name, uint32_t type, const struct vb2_hash *hash);
+tpm_result_t tspi_cbfs_measurement(const char *name, uint32_t type, const struct vb2_hash *hash);
 
 /*
  * Provide a function on SoC level to measure the bootblock for cases where bootblock is
diff --git a/src/security/tpm/tspi/tspi.c b/src/security/tpm/tspi/tspi.c
index aee1cf4709..80f33d59c6 100644
--- a/src/security/tpm/tspi/tspi.c
+++ b/src/security/tpm/tspi/tspi.c
@@ -11,16 +11,16 @@
 #include <vb2_sha.h>
 
 #if CONFIG(TPM1)
-static uint32_t tpm1_invoke_state_machine(void)
+static tpm_result_t tpm1_invoke_state_machine(void)
 {
 	uint8_t disabled;
 	uint8_t deactivated;
-	uint32_t rc = TPM_SUCCESS;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Check that the TPM is enabled and activated. */
 	rc = tlcl_get_flags(&disabled, &deactivated, NULL);
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't read capabilities.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't read capabilities.\n", rc);
 		return rc;
 	}
 
@@ -29,7 +29,7 @@ static uint32_t tpm1_invoke_state_machine(void)
 
 		rc = tlcl_set_enable();
 		if (rc != TPM_SUCCESS) {
-			printk(BIOS_ERR, "TPM: Can't set enabled state.\n");
+			printk(BIOS_ERR, "TPM Error (%#x): Can't set enabled state.\n", rc);
 			return rc;
 		}
 	}
@@ -40,7 +40,7 @@ static uint32_t tpm1_invoke_state_machine(void)
 		rc = tlcl_set_deactivated(!deactivated);
 		if (rc != TPM_SUCCESS) {
 			printk(BIOS_ERR,
-			       "TPM: Can't toggle deactivated state.\n");
+			       "TPM Error (%#x): Can't toggle deactivated state.\n", rc);
 			return rc;
 		}
 
@@ -52,11 +52,9 @@ static uint32_t tpm1_invoke_state_machine(void)
 }
 #endif
 
-static uint32_t tpm_setup_s3_helper(void)
+static tpm_result_t tpm_setup_s3_helper(void)
 {
-	uint32_t rc;
-
-	rc = tlcl_resume();
+	tpm_result_t rc = tlcl_resume();
 	switch (rc) {
 	case TPM_SUCCESS:
 		break;
@@ -78,7 +76,7 @@ static uint32_t tpm_setup_s3_helper(void)
 	return rc;
 }
 
-static uint32_t tpm_setup_epilogue(uint32_t rc)
+static tpm_result_t tpm_setup_epilogue(tpm_result_t rc)
 {
 	if (rc != TPM_SUCCESS)
 		post_code(POSTCODE_TPM_FAILURE);
@@ -133,13 +131,13 @@ static inline int tspi_tpm_is_setup(void)
  * to the TPM flashram at every reboot or wake-up, because of concerns about
  * the durability of the NVRAM.
  */
-uint32_t tpm_setup(int s3flag)
+tpm_result_t tpm_setup(int s3flag)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = tlcl_lib_init();
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't initialize.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't initialize.\n", rc);
 		return tpm_setup_epilogue(rc);
 	}
 
@@ -152,11 +150,11 @@ uint32_t tpm_setup(int s3flag)
 	rc = tlcl_startup();
 	if (CONFIG(TPM_STARTUP_IGNORE_POSTINIT)
 	    && rc == TPM_INVALID_POSTINIT) {
-		printk(BIOS_DEBUG, "TPM: ignoring invalid POSTINIT\n");
+		printk(BIOS_DEBUG, "TPM Warn(%#x): ignoring invalid POSTINIT\n", rc);
 		rc = TPM_SUCCESS;
 	}
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't run startup command.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't run startup command.\n", rc);
 		return tpm_setup_epilogue(rc);
 	}
 
@@ -169,13 +167,13 @@ uint32_t tpm_setup(int s3flag)
 		 */
 		rc = tlcl_physical_presence_cmd_enable();
 		if (rc != TPM_SUCCESS) {
-			printk(BIOS_ERR, "TPM: Can't enable physical presence command.\n");
+			printk(BIOS_ERR, "TPM Error (%#x): Can't enable physical presence command.\n", rc);
 			return tpm_setup_epilogue(rc);
 		}
 
 		rc = tlcl_assert_physical_presence();
 		if (rc != TPM_SUCCESS) {
-			printk(BIOS_ERR, "TPM: Can't assert physical presence.\n");
+			printk(BIOS_ERR, "TPM Error (%#x): Can't assert physical presence.\n", rc);
 			return tpm_setup_epilogue(rc);
 		}
 	}
@@ -190,27 +188,27 @@ uint32_t tpm_setup(int s3flag)
 	return tpm_setup_epilogue(rc);
 }
 
-uint32_t tpm_clear_and_reenable(void)
+tpm_result_t tpm_clear_and_reenable(void)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	printk(BIOS_INFO, "TPM: Clear and re-enable\n");
 	rc = tlcl_force_clear();
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't initiate a force clear.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't initiate a force clear.\n", rc);
 		return rc;
 	}
 
 #if CONFIG(TPM1)
 	rc = tlcl_set_enable();
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't set enabled state.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't set enabled state.\n", rc);
 		return rc;
 	}
 
 	rc = tlcl_set_deactivated(0);
 	if (rc != TPM_SUCCESS) {
-		printk(BIOS_ERR, "TPM: Can't set deactivated state.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Can't set deactivated state.\n", rc);
 		return rc;
 	}
 #endif
@@ -218,10 +216,10 @@ uint32_t tpm_clear_and_reenable(void)
 	return TPM_SUCCESS;
 }
 
-uint32_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
+tpm_result_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
 			const uint8_t *digest, size_t digest_len, const char *name)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	if (!digest)
 		return TPM_IOERROR;
@@ -229,15 +227,15 @@ uint32_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
 	if (tspi_tpm_is_setup()) {
 		rc = tlcl_lib_init();
 		if (rc != TPM_SUCCESS) {
-			printk(BIOS_ERR, "TPM: Can't initialize library.\n");
+			printk(BIOS_ERR, "TPM Error (%#x): Can't initialize library.\n", rc);
 			return rc;
 		}
 
 		printk(BIOS_DEBUG, "TPM: Extending digest for `%s` into PCR %d\n", name, pcr);
 		rc = tlcl_extend(pcr, digest, digest_algo);
 		if (rc != TPM_SUCCESS) {
-			printk(BIOS_ERR, "TPM: Extending hash for `%s` into PCR %d failed.\n",
-			       name, pcr);
+			printk(BIOS_ERR, "TPM Error (%#x): Extending hash for `%s` into PCR %d failed.\n",
+			       rc, name, pcr);
 			return rc;
 		}
 	}
@@ -252,7 +250,7 @@ uint32_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
 }
 
 #if CONFIG(VBOOT_LIB)
-uint32_t tpm_measure_region(const struct region_device *rdev, uint8_t pcr,
+tpm_result_t tpm_measure_region(const struct region_device *rdev, uint8_t pcr,
 			    const char *rname)
 {
 	uint8_t digest[TPM_PCR_MAX_LEN], digest_len;
diff --git a/src/security/tpm/tss.h b/src/security/tpm/tss.h
index fa8cf52cff..9a5521f086 100644
--- a/src/security/tpm/tss.h
+++ b/src/security/tpm/tss.h
@@ -23,29 +23,29 @@
  * Define a space with permission [perm]. [index] is the index for the space,
  * [size] the usable data size. The TPM error code is returned.
  */
-uint32_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size);
+tpm_result_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size);
 
 /**
  * Issue a PhysicalEnable. The TPM error code is returned.
  */
-uint32_t tlcl_set_enable(void);
+tpm_result_t tlcl_set_enable(void);
 
 /**
  * Issue a SetDeactivated. Pass 0 to activate. Returns result code.
  */
-uint32_t tlcl_set_deactivated(uint8_t flag);
+tpm_result_t tlcl_set_deactivated(uint8_t flag);
 
 /**
  * Get flags of interest. Pointers for flags you aren't interested in may
  * be NULL. The TPM error code is returned.
  */
-uint32_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated,
-			uint8_t *nvlocked);
+tpm_result_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated,
+			    uint8_t *nvlocked);
 
 /**
  * Get the entire set of permanent flags.
  */
-uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags);
+tpm_result_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags);
 
 #endif
 
@@ -57,19 +57,19 @@ uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags);
  * Define a TPM2 space. The define space command TPM command used by the tlcl
  * layer offers the ability to use custom nv attributes and policies.
  */
-uint32_t tlcl_define_space(uint32_t space_index, size_t space_size,
+tpm_result_t tlcl_define_space(uint32_t space_index, size_t space_size,
 			   const TPMA_NV nv_attributes,
 			   const uint8_t *nv_policy, size_t nv_policy_size);
 
 /*
  * Issue TPM2_GetCapability command
  */
-uint32_t tlcl_get_capability(TPM_CAP capability, uint32_t property,
+tpm_result_t tlcl_get_capability(TPM_CAP capability, uint32_t property,
 			     uint32_t property_count,
 			     TPMS_CAPABILITY_DATA *capability_data);
 
 /* Issue TPM2_NV_SetBits command */
-uint32_t tlcl_set_bits(uint32_t index, uint64_t bits);
+tpm_result_t tlcl_set_bits(uint32_t index, uint64_t bits);
 
 /*
  * Makes tpm_process_command available for on top implementations of
@@ -88,12 +88,12 @@ uint16_t tlcl_get_hash_size_from_algo(TPMI_ALG_HASH hash_algo);
 /**
  * Call this first.  Returns 0 if success, nonzero if error.
  */
-uint32_t tlcl_lib_init(void);
+tpm_result_t tlcl_lib_init(void);
 
 /**
  * Perform a raw TPM request/response transaction.
  */
-uint32_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
+tpm_result_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
 			   int max_length);
 
 /* Commands */
@@ -102,20 +102,20 @@ uint32_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
  * Send a TPM_Startup(ST_CLEAR).  The TPM error code is returned (0 for
  * success).
  */
-uint32_t tlcl_startup(void);
+tpm_result_t tlcl_startup(void);
 
 /**
  * Resume by sending a TPM_Startup(ST_STATE).  The TPM error code is returned
  * (0 for success).
  */
-uint32_t tlcl_resume(void);
+tpm_result_t tlcl_resume(void);
 
 /**
  * Save TPM state by sending either TPM_SaveState() (TPM1.2) or
  * TPM_Shutdown(ST_STATE) (TPM2.0).  The TPM error code is returned (0 for
  * success).
  */
-uint32_t tlcl_save_state(void);
+tpm_result_t tlcl_save_state(void);
 
 /**
  * Run the self test.
@@ -123,81 +123,81 @@ uint32_t tlcl_save_state(void);
  * Note---this is synchronous.  To run this in parallel with other firmware,
  * use ContinueSelfTest().  The TPM error code is returned.
  */
-uint32_t tlcl_self_test_full(void);
+tpm_result_t tlcl_self_test_full(void);
 
 /**
  * Run the self test in the background.
  */
-uint32_t tlcl_continue_self_test(void);
+tpm_result_t tlcl_continue_self_test(void);
 
 /**
  * Write [length] bytes of [data] to space at [index].  The TPM error code is
  * returned.
  */
-uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length);
+tpm_result_t tlcl_write(uint32_t index, const void *data, uint32_t length);
 
 /**
  * Read [length] bytes from space at [index] into [data].  The TPM error code
  * is returned.
  */
-uint32_t tlcl_read(uint32_t index, void *data, uint32_t length);
+tpm_result_t tlcl_read(uint32_t index, void *data, uint32_t length);
 
 /**
  * Assert physical presence in software.  The TPM error code is returned.
  */
-uint32_t tlcl_assert_physical_presence(void);
+tpm_result_t tlcl_assert_physical_presence(void);
 
 /**
  * Enable the physical presence command.  The TPM error code is returned.
  */
-uint32_t tlcl_physical_presence_cmd_enable(void);
+tpm_result_t tlcl_physical_presence_cmd_enable(void);
 
 /**
  * Finalize the physical presence settings: software PP is enabled, hardware PP
  * is disabled, and the lifetime lock is set.  The TPM error code is returned.
  */
-uint32_t tlcl_finalize_physical_presence(void);
+tpm_result_t tlcl_finalize_physical_presence(void);
 
 /**
  * Set the nvLocked bit.  The TPM error code is returned.
  */
-uint32_t tlcl_set_nv_locked(void);
+tpm_result_t tlcl_set_nv_locked(void);
 
 /**
  * Issue a ForceClear.  The TPM error code is returned.
  */
-uint32_t tlcl_force_clear(void);
+tpm_result_t tlcl_force_clear(void);
 
 /**
  * Set Clear Control. The TPM error code is returned.
  */
-uint32_t tlcl_clear_control(bool disable);
+tpm_result_t tlcl_clear_control(bool disable);
 
 /**
  * Set the bGlobalLock flag, which only a reboot can clear.  The TPM error
  * code is returned.
  */
-uint32_t tlcl_set_global_lock(void);
+tpm_result_t tlcl_set_global_lock(void);
 
 /**
  * Make an NV Ram location read_only.  The TPM error code is returned.
  */
-uint32_t tlcl_lock_nv_write(uint32_t index);
+tpm_result_t tlcl_lock_nv_write(uint32_t index);
 
 /**
  * Perform a TPM_Extend.
  */
-uint32_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
+tpm_result_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
 		     enum vb2_hash_algorithm digest_algo);
 
 /**
  * Disable platform hierarchy. Specific to TPM2. The TPM error code is returned.
  */
-uint32_t tlcl_disable_platform_hierarchy(void);
+tpm_result_t tlcl_disable_platform_hierarchy(void);
 
 /**
  * Get the permission bits for the NVRAM space with |index|.
  */
-uint32_t tlcl_get_permissions(uint32_t index, uint32_t *permissions);
+tpm_result_t tlcl_get_permissions(uint32_t index, uint32_t *permissions);
 
 #endif /* TSS_H_ */
diff --git a/src/security/tpm/tss/tcg-1.2/tss.c b/src/security/tpm/tss/tcg-1.2/tss.c
index 076b8a7562..e73db388e8 100644
--- a/src/security/tpm/tss/tcg-1.2/tss.c
+++ b/src/security/tpm/tss/tcg-1.2/tss.c
@@ -24,19 +24,21 @@
 #include <console/console.h>
 #define VBDEBUG(format, args...) printk(BIOS_DEBUG, format, ## args)
 
-static int tpm_send_receive(const uint8_t *request,
+static tpm_result_t tpm_send_receive(const uint8_t *request,
 				uint32_t request_length,
 				uint8_t *response,
 				uint32_t *response_length)
 {
 	size_t len = *response_length;
-	if (tis_sendrecv(request, request_length, response, &len))
-		return VB2_ERROR_UNKNOWN;
+	tpm_result_t rc = tis_sendrecv(request, request_length, response, &len);
+	if (rc)
+		return rc;
 	/* check 64->32bit overflow and (re)check response buffer overflow */
 	if (len > *response_length)
-		return VB2_ERROR_UNKNOWN;
-	*response_length = len;
-	return VB2_SUCCESS;
+		rc = TPM_CB_FAIL;
+	else
+		*response_length = len;
+	return rc;
 }
 
 /* Sets the size field of a TPM command. */
@@ -55,15 +57,15 @@ static inline int tpm_command_size(const uint8_t *buffer)
 }
 
 /* Gets the code field of a TPM command. */
-static inline int tpm_command_code(const uint8_t *buffer)
+static inline tpm_result_t tpm_command_code(const uint8_t *buffer)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 	from_tpm_uint32(buffer + sizeof(uint16_t) + sizeof(uint32_t), &rc);
 	return rc;
 }
 
 /* Gets the return code field of a TPM result. */
-static inline int tpm_return_code(const uint8_t *buffer)
+static inline tpm_result_t tpm_return_code(const uint8_t *buffer)
 {
 	return tpm_command_code(buffer);
 }
@@ -72,15 +74,15 @@ static inline int tpm_return_code(const uint8_t *buffer)
  * Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or
  * DOING_SELFTEST errors are returned.
  */
-static uint32_t tlcl_send_receive_no_retry(const uint8_t *request,
+static tpm_result_t tlcl_send_receive_no_retry(const uint8_t *request,
 					   uint8_t *response, int max_length)
 {
 	uint32_t response_length = max_length;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = tpm_send_receive(request, tpm_command_size(request),
 					response, &response_length);
-	if (rc != 0) {
+	if (rc != TPM_SUCCESS) {
 		/* Communication with TPM failed, so response is garbage */
 		VBDEBUG("TPM: command %#x send/receive failed: %#x\n",
 			tpm_command_code(request), rc);
@@ -96,15 +98,15 @@ static uint32_t tlcl_send_receive_no_retry(const uint8_t *request,
 	VBDEBUG("TPM: command %#x returned %#x\n",
 		tpm_command_code(request), rc);
 
-return rc;
+	return rc;
 }
 
 /* Sends a TPM command and gets a response.  Returns 0 if success or the TPM
  * error code if error. Waits for the self test to complete if needed. */
-uint32_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
+tpm_result_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
 			   int max_length)
 {
-	uint32_t rc = tlcl_send_receive_no_retry(request, response,
+	tpm_result_t rc = tlcl_send_receive_no_retry(request, response,
 						     max_length);
 	/* If the command fails because the self test has not completed, try it
 	 * again after attempting to ensure that the self test has completed. */
@@ -132,7 +134,7 @@ uint32_t tlcl_send_receive(const uint8_t *request, uint8_t *response,
 }
 
 /* Sends a command and returns the error code. */
-static uint32_t send(const uint8_t *command)
+static tpm_result_t send(const uint8_t *command)
 {
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 	return tlcl_send_receive(command, response, sizeof(response));
@@ -142,46 +144,48 @@ static uint32_t send(const uint8_t *command)
 
 static uint8_t tlcl_init_done;
 
-uint32_t tlcl_lib_init(void)
+tpm_result_t tlcl_lib_init(void)
 {
+	tpm_result_t rc = TPM_SUCCESS;
 	if (tlcl_init_done)
-		return VB2_SUCCESS;
-
-	if (tis_init())
-		return VB2_ERROR_UNKNOWN;
-	if (tis_open())
-		return VB2_ERROR_UNKNOWN;
+		return rc;
+	rc = tis_init();
+	if (rc)
+		return rc;
+	rc = tis_open();
+	if (rc)
+		return rc;
 
 	tlcl_init_done = 1;
 
-	return VB2_SUCCESS;
+	return rc;
 }
 
-uint32_t tlcl_startup(void)
+tpm_result_t tlcl_startup(void)
 {
 	VBDEBUG("TPM: Startup\n");
 	return send(tpm_startup_cmd.buffer);
 }
 
-uint32_t tlcl_resume(void)
+tpm_result_t tlcl_resume(void)
 {
 	VBDEBUG("TPM: Resume\n");
 	return send(tpm_resume_cmd.buffer);
 }
 
-uint32_t tlcl_save_state(void)
+tpm_result_t tlcl_save_state(void)
 {
 	VBDEBUG("TPM: Save state\n");
 	return send(tpm_savestate_cmd.buffer);
 }
 
-uint32_t tlcl_self_test_full(void)
+tpm_result_t tlcl_self_test_full(void)
 {
 	VBDEBUG("TPM: Self test full\n");
 	return send(tpm_selftestfull_cmd.buffer);
 }
 
-uint32_t tlcl_continue_self_test(void)
+tpm_result_t tlcl_continue_self_test(void)
 {
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 	VBDEBUG("TPM: Continue self test\n");
@@ -190,7 +194,7 @@ uint32_t tlcl_continue_self_test(void)
 					  response, sizeof(response));
 }
 
-uint32_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size)
+tpm_result_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size)
 {
 	struct s_tpm_nv_definespace_cmd cmd;
 	VBDEBUG("TPM: TlclDefineSpace(%#x, %#x, %d)\n", index, perm, size);
@@ -201,7 +205,7 @@ uint32_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size)
 	return send(cmd.buffer);
 }
 
-uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length)
+tpm_result_t tlcl_write(uint32_t index, const void *data, uint32_t length)
 {
 	struct s_tpm_nv_write_cmd cmd;
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
@@ -221,12 +225,12 @@ uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length)
 	return tlcl_send_receive(cmd.buffer, response, sizeof(response));
 }
 
-uint32_t tlcl_read(uint32_t index, void *data, uint32_t length)
+tpm_result_t tlcl_read(uint32_t index, void *data, uint32_t length)
 {
 	struct s_tpm_nv_read_cmd cmd;
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 	uint32_t result_length;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	VBDEBUG("TPM: %s(%#x, %d)\n", __func__, index, length);
 	memcpy(&cmd, &tpm_nv_read_cmd, sizeof(cmd));
@@ -246,43 +250,43 @@ uint32_t tlcl_read(uint32_t index, void *data, uint32_t length)
 	return rc;
 }
 
-uint32_t tlcl_assert_physical_presence(void)
+tpm_result_t tlcl_assert_physical_presence(void)
 {
 	VBDEBUG("TPM: Asserting physical presence\n");
 	return send(tpm_ppassert_cmd.buffer);
 }
 
-uint32_t tlcl_physical_presence_cmd_enable(void)
+tpm_result_t tlcl_physical_presence_cmd_enable(void)
 {
 	VBDEBUG("TPM: Enable the physical presence command\n");
 	return send(tpm_ppenable_cmd.buffer);
 }
 
-uint32_t tlcl_finalize_physical_presence(void)
+tpm_result_t tlcl_finalize_physical_presence(void)
 {
 	VBDEBUG("TPM: Enable PP cmd, disable HW pp, and set lifetime lock\n");
 	return send(tpm_finalizepp_cmd.buffer);
 }
 
-uint32_t tlcl_set_nv_locked(void)
+tpm_result_t tlcl_set_nv_locked(void)
 {
 	VBDEBUG("TPM: Set NV locked\n");
 	return tlcl_define_space(TPM_NV_INDEX_LOCK, 0, 0);
 }
 
-uint32_t tlcl_force_clear(void)
+tpm_result_t tlcl_force_clear(void)
 {
 	VBDEBUG("TPM: Force clear\n");
 	return send(tpm_forceclear_cmd.buffer);
 }
 
-uint32_t tlcl_set_enable(void)
+tpm_result_t tlcl_set_enable(void)
 {
 	VBDEBUG("TPM: Enabling TPM\n");
 	return send(tpm_physicalenable_cmd.buffer);
 }
 
-uint32_t tlcl_set_deactivated(uint8_t flag)
+tpm_result_t tlcl_set_deactivated(uint8_t flag)
 {
 	struct s_tpm_physicalsetdeactivated_cmd cmd;
 	VBDEBUG("TPM: SetDeactivated(%d)\n", flag);
@@ -291,11 +295,11 @@ uint32_t tlcl_set_deactivated(uint8_t flag)
 	return send(cmd.buffer);
 }
 
-uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags)
+tpm_result_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags)
 {
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 	uint32_t size;
-	uint32_t rc = tlcl_send_receive(tpm_getflags_cmd.buffer, response,
+	tpm_result_t rc = tlcl_send_receive(tpm_getflags_cmd.buffer, response,
 					    sizeof(response));
 	if (rc != TPM_SUCCESS)
 		return rc;
@@ -307,11 +311,11 @@ uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags)
 	return rc;
 }
 
-uint32_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated,
+tpm_result_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated,
 			uint8_t *nvlocked)
 {
 	TPM_PERMANENT_FLAGS pflags;
-	uint32_t rc = tlcl_get_permanent_flags(&pflags);
+	tpm_result_t rc = tlcl_get_permanent_flags(&pflags);
 	if (rc == TPM_SUCCESS) {
 		if (disable)
 			*disable = pflags.disable;
@@ -325,13 +329,13 @@ uint32_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated,
 	return rc;
 }
 
-uint32_t tlcl_set_global_lock(void)
+tpm_result_t tlcl_set_global_lock(void)
 {
 	VBDEBUG("TPM: Set global lock\n");
 	return tlcl_write(TPM_NV_INDEX0, NULL, 0);
 }
 
-uint32_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
+tpm_result_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
 		     enum vb2_hash_algorithm digest_algo)
 {
 	struct s_tpm_extend_cmd cmd;
@@ -347,12 +351,12 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
 	return tlcl_send_receive(cmd.buffer, response, sizeof(response));
 }
 
-uint32_t tlcl_get_permissions(uint32_t index, uint32_t *permissions)
+tpm_result_t tlcl_get_permissions(uint32_t index, uint32_t *permissions)
 {
 	struct s_tpm_getpermissions_cmd cmd;
 	uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 	uint8_t *nvdata;
-	uint32_t rc;
+	tpm_result_t rc;
 	uint32_t size;
 
 	memcpy(&cmd, &tpm_getpermissions_cmd, sizeof(cmd));
diff --git a/src/security/tpm/tss/tcg-2.0/tss.c b/src/security/tpm/tss/tcg-2.0/tss.c
index e780bd24d3..e23a0d280d 100644
--- a/src/security/tpm/tss/tcg-2.0/tss.c
+++ b/src/security/tpm/tss/tcg-2.0/tss.c
@@ -46,7 +46,7 @@ void *tpm_process_command(TPM_CC command, void *command_body)
 	return tpm_unmarshal_response(command, &ib);
 }
 
-static uint32_t tlcl_send_startup(TPM_SU type)
+static tpm_result_t tlcl_send_startup(TPM_SU type)
 {
 	struct tpm2_startup startup;
 	struct tpm2_response *response;
@@ -75,12 +75,12 @@ static uint32_t tlcl_send_startup(TPM_SU type)
 	return TPM_IOERROR;
 }
 
-uint32_t tlcl_resume(void)
+tpm_result_t tlcl_resume(void)
 {
 	return tlcl_send_startup(TPM_SU_STATE);
 }
 
-static uint32_t tlcl_send_shutdown(TPM_SU type)
+static tpm_result_t tlcl_send_shutdown(TPM_SU type)
 {
 	struct tpm2_shutdown shutdown;
 	struct tpm2_response *response;
@@ -104,12 +104,12 @@ static uint32_t tlcl_send_shutdown(TPM_SU type)
 	return TPM_IOERROR;
 }
 
-uint32_t tlcl_save_state(void)
+tpm_result_t tlcl_save_state(void)
 {
 	return tlcl_send_shutdown(TPM_SU_STATE);
 }
 
-uint32_t tlcl_assert_physical_presence(void)
+tpm_result_t tlcl_assert_physical_presence(void)
 {
 	/*
 	 * Nothing to do on TPM2 for this, use platform hierarchy availability
@@ -135,7 +135,7 @@ static TPM_ALG_ID tpmalg_from_vb2_hash(enum vb2_hash_algorithm hash_type)
 	}
 }
 
-uint32_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
+tpm_result_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
 		     enum vb2_hash_algorithm digest_type)
 {
 	struct tpm2_pcr_extend_cmd pcr_ext_cmd;
@@ -163,14 +163,14 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t *digest_data,
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_finalize_physical_presence(void)
+tpm_result_t tlcl_finalize_physical_presence(void)
 {
 	/* Nothing needs to be done with tpm2. */
 	printk(BIOS_INFO, "%s:%s:%d\n", __FILE__, __func__, __LINE__);
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_force_clear(void)
+tpm_result_t tlcl_force_clear(void)
 {
 	struct tpm2_response *response;
 
@@ -184,7 +184,7 @@ uint32_t tlcl_force_clear(void)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_clear_control(bool disable)
+tpm_result_t tlcl_clear_control(bool disable)
 {
 	struct tpm2_response *response;
 	struct tpm2_clear_control_cmd cc = {
@@ -204,33 +204,36 @@ uint32_t tlcl_clear_control(bool disable)
 static uint8_t tlcl_init_done;
 
 /* This function is called directly by vboot, uses vboot return types. */
-uint32_t tlcl_lib_init(void)
+tpm_result_t tlcl_lib_init(void)
 {
+	tpm_result_t rc = TPM_SUCCESS;
 	if (tlcl_init_done)
-		return VB2_SUCCESS;
+		return rc;
 
-	if (tis_init()) {
-		printk(BIOS_ERR, "%s: tis_init returned error\n", __func__);
-		return VB2_ERROR_UNKNOWN;
+	rc = tis_init();
+	if (rc) {
+		printk(BIOS_ERR, "%s: tis_init returned error %d\n", __func__, rc);
+		return rc;
 	}
-
-	if (tis_open()) {
-		printk(BIOS_ERR, "%s: tis_open returned error\n", __func__);
-		return VB2_ERROR_UNKNOWN;
+	rc = tis_open();
+	if (rc) {
+		printk(BIOS_ERR, "%s: tis_open returned error %d\n"
+			, __func__, rc);
+		return rc;
 	}
 
 	tlcl_init_done = 1;
 
-	return VB2_SUCCESS;
+	return rc;
 }
 
-uint32_t tlcl_physical_presence_cmd_enable(void)
+tpm_result_t tlcl_physical_presence_cmd_enable(void)
 {
 	printk(BIOS_INFO, "%s:%s:%d\n", __FILE__, __func__, __LINE__);
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_read(uint32_t index, void *data, uint32_t length)
+tpm_result_t tlcl_read(uint32_t index, void *data, uint32_t length)
 {
 	struct tpm2_nv_read_cmd nv_readc;
 	struct tpm2_response *response;
@@ -279,7 +282,7 @@ uint32_t tlcl_read(uint32_t index, void *data, uint32_t length)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_self_test_full(void)
+tpm_result_t tlcl_self_test_full(void)
 {
 	struct tpm2_self_test st;
 	struct tpm2_response *response;
@@ -292,7 +295,7 @@ uint32_t tlcl_self_test_full(void)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_lock_nv_write(uint32_t index)
+tpm_result_t tlcl_lock_nv_write(uint32_t index)
 {
 	struct tpm2_response *response;
 	/* TPM Will reject attempts to write at non-defined index. */
@@ -311,12 +314,12 @@ uint32_t tlcl_lock_nv_write(uint32_t index)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_startup(void)
+tpm_result_t tlcl_startup(void)
 {
 	return tlcl_send_startup(TPM_SU_CLEAR);
 }
 
-uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length)
+tpm_result_t tlcl_write(uint32_t index, const void *data, uint32_t length)
 {
 	struct tpm2_nv_write_cmd nv_writec;
 	struct tpm2_response *response;
@@ -339,7 +342,7 @@ uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_set_bits(uint32_t index, uint64_t bits)
+tpm_result_t tlcl_set_bits(uint32_t index, uint64_t bits)
 {
 	struct tpm2_nv_setbits_cmd nvsb_cmd;
 	struct tpm2_response *response;
@@ -362,7 +365,7 @@ uint32_t tlcl_set_bits(uint32_t index, uint64_t bits)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_define_space(uint32_t space_index, size_t space_size,
+tpm_result_t tlcl_define_space(uint32_t space_index, size_t space_size,
 			   const TPMA_NV nv_attributes,
 			   const uint8_t *nv_policy, size_t nv_policy_size)
 {
@@ -437,7 +440,7 @@ uint16_t tlcl_get_hash_size_from_algo(TPMI_ALG_HASH hash_algo)
 	return value;
 }
 
-uint32_t tlcl_disable_platform_hierarchy(void)
+tpm_result_t tlcl_disable_platform_hierarchy(void)
 {
 	struct tpm2_response *response;
 	struct tpm2_hierarchy_control_cmd hc = {
@@ -453,7 +456,7 @@ uint32_t tlcl_disable_platform_hierarchy(void)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_get_capability(TPM_CAP capability, uint32_t property,
+tpm_result_t tlcl_get_capability(TPM_CAP capability, uint32_t property,
 		uint32_t property_count,
 		TPMS_CAPABILITY_DATA *capability_data)
 {
diff --git a/src/security/tpm/tss/vendor/cr50/cr50.c b/src/security/tpm/tss/vendor/cr50/cr50.c
index 1711501323..87889d128b 100644
--- a/src/security/tpm/tss/vendor/cr50/cr50.c
+++ b/src/security/tpm/tss/vendor/cr50/cr50.c
@@ -9,7 +9,7 @@
 
 #include "../../tcg-2.0/tss_marshaling.h"
 
-uint32_t tlcl_cr50_enable_nvcommits(void)
+tpm_result_t tlcl_cr50_enable_nvcommits(void)
 {
 	uint16_t sub_command = TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS;
 	struct tpm2_response *response;
@@ -29,8 +29,8 @@ uint32_t tlcl_cr50_enable_nvcommits(void)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms,
-				 uint8_t *num_restored_headers)
+tpm_result_t tlcl_cr50_enable_update(uint16_t timeout_ms,
+				     uint8_t *num_restored_headers)
 {
 	struct tpm2_response *response;
 	uint16_t command_body[] = {
@@ -48,7 +48,7 @@ uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms,
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state)
+tpm_result_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state)
 {
 	struct tpm2_response *response;
 	uint16_t sub_command = TPM2_CR50_SUB_CMD_GET_REC_BTN;
@@ -64,7 +64,7 @@ uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode)
+tpm_result_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode)
 {
 	struct tpm2_response *response;
 	uint16_t mode_command = TPM2_CR50_SUB_CMD_TPM_MODE;
@@ -105,7 +105,7 @@ uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode)
+tpm_result_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode)
 {
 	struct tpm2_response *response;
 	uint16_t mode_command = TPM2_CR50_SUB_CMD_GET_BOOT_MODE;
@@ -131,7 +131,7 @@ uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_immediate_reset(uint16_t timeout_ms)
+tpm_result_t tlcl_cr50_immediate_reset(uint16_t timeout_ms)
 {
 	struct tpm2_response *response;
 	uint16_t reset_command_body[] = {
@@ -150,7 +150,7 @@ uint32_t tlcl_cr50_immediate_reset(uint16_t timeout_ms)
 	return TPM_SUCCESS;
 }
 
-uint32_t tlcl_cr50_reset_ec(void)
+tpm_result_t tlcl_cr50_reset_ec(void)
 {
 	struct tpm2_response *response;
 	uint16_t reset_cmd = TPM2_CR50_SUB_CMD_RESET_EC;
diff --git a/src/security/tpm/tss/vendor/cr50/cr50.h b/src/security/tpm/tss/vendor/cr50/cr50.h
index ee6b30f6d5..edd5083d17 100644
--- a/src/security/tpm/tss/vendor/cr50/cr50.h
+++ b/src/security/tpm/tss/vendor/cr50/cr50.h
@@ -3,6 +3,7 @@
 #define CR50_TSS_STRUCTURES_H_
 
 #include <stdint.h>
+#include <security/tpm/tss_errors.h>
 
 /* FIXME: below is not enough to differentiate between vendors commands
    of numerous devices. However, the current tpm2 APIs aren't very amenable
@@ -45,7 +46,7 @@ enum cr50_tpm_mode {
  * CR50 specific tpm command to enable nvmem commits before internal timeout
  * expires.
  */
-uint32_t tlcl_cr50_enable_nvcommits(void);
+tpm_result_t tlcl_cr50_enable_nvcommits(void);
 
 /**
  * CR50 specific tpm command to restore header(s) of the dormant RO/RW
@@ -56,8 +57,8 @@ uint32_t tlcl_cr50_enable_nvcommits(void);
  * Return value indicates success or failure of accessing the TPM; in case of
  * success the number of restored headers is saved in num_restored_headers.
  */
-uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms,
-				 uint8_t *num_restored_headers);
+tpm_result_t tlcl_cr50_enable_update(uint16_t timeout_ms,
+				     uint8_t *num_restored_headers);
 
 /**
  * CR50 specific tpm command to get the latched state of the recovery button.
@@ -65,7 +66,7 @@ uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms,
  * Return value indicates success or failure of accessing the TPM; in case of
  * success the recovery button state is saved in recovery_button_state.
  */
-uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state);
+tpm_result_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state);
 
 /**
  * CR50 specific TPM command sequence to query the current TPM mode.
@@ -77,7 +78,7 @@ uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state);
  * Returns TPM_CB_NO_SUCH_COMMAND if the Cr50 does not support the command.
  * Other returns value indicate a failure accessing the TPM.
  */
-uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode);
+tpm_result_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode);
 
 /**
  * CR50 specific TPM command sequence to query the current boot mode.
@@ -85,7 +86,7 @@ uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode);
  * Returns TPM_SUCCESS if boot mode is successfully retrieved.
  * Returns TPM_* for errors.
  */
-uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode);
+tpm_result_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode);
 
 /**
  * CR50 specific TPM command sequence to trigger an immediate reset to the Cr50
@@ -94,7 +95,7 @@ uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode);
  *
  * Return value indicates success or failure of accessing the TPM.
  */
-uint32_t tlcl_cr50_immediate_reset(uint16_t timeout_ms);
+tpm_result_t tlcl_cr50_immediate_reset(uint16_t timeout_ms);
 
 /**
  * CR50 specific TPM command sequence to issue an EC reset.
@@ -102,6 +103,6 @@ uint32_t tlcl_cr50_immediate_reset(uint16_t timeout_ms);
  * Returns TPM_* for errors.
  * On Success, this function invokes halt() and does not return.
  */
-uint32_t tlcl_cr50_reset_ec(void);
+tpm_result_t tlcl_cr50_reset_ec(void);
 
 #endif /* CR50_TSS_STRUCTURES_H_ */
diff --git a/src/security/tpm/tss_errors.h b/src/security/tpm/tss_errors.h
index 3545f04110..8198ca1940 100644
--- a/src/security/tpm/tss_errors.h
+++ b/src/security/tpm/tss_errors.h
@@ -4,7 +4,7 @@
  * TPM error codes.
  *
  * Copy-pasted and lightly edited from TCG TPM Main Part 2 TPM Structures
- * Version 1.2 Level 2 Revision 103 26 October 2006 Draft.
+ * Version 1.2 Level 2 Revision 116 1 March 2011.
  */
 
 #ifndef TSS_ERRORS_H_
@@ -17,11 +17,13 @@ typedef uint32_t tpm_result_t;
 
 #define TPM_BASE 0x0
 
-#define TPM_NON_FATAL 0x800
+#define TPM_NON_FATAL (0x800 + TPM_BASE)
 #define TPM_CB_ERROR TPM_Vendor_Specific32
 
 #define TPM_SUCCESS               ((tpm_result_t) (TPM_BASE + 0x00))
 #define TPM_BADINDEX              ((tpm_result_t) (TPM_BASE + 0x02))
+#define TPM_BAD_PARAMETER         ((tpm_result_t) (TPM_BASE + 0x03))
+#define TPM_FAIL                  ((tpm_result_t) (TPM_BASE + 0x09))
 #define TPM_OWNER_SET             ((tpm_result_t) (TPM_BASE + 0x14))
 #define TPM_IOERROR               ((tpm_result_t) (TPM_BASE + 0x1F))
 #define TPM_INVALID_POSTINIT      ((tpm_result_t) (TPM_BASE + 0x26))
@@ -29,6 +31,7 @@ typedef uint32_t tpm_result_t;
 #define TPM_AREA_LOCKED           ((tpm_result_t) (TPM_BASE + 0x3C))
 #define TPM_MAXNVWRITES           ((tpm_result_t) (TPM_BASE + 0x48))
 
+#define TPM_RETRY          ((tpm_result_t) (TPM_NON_FATAL + 0x00))
 #define TPM_NEEDS_SELFTEST ((tpm_result_t) (TPM_NON_FATAL + 0x01))
 #define TPM_DOING_SELFTEST ((tpm_result_t) (TPM_NON_FATAL + 0x02))
 
@@ -56,5 +59,7 @@ typedef uint32_t tpm_result_t;
 #define TPM_CB_HASH_ERROR             ((tpm_result_t) (TPM_CB_ERROR + 0x8D))
 #define TPM_CB_NO_SUCH_COMMAND        ((tpm_result_t) (TPM_CB_ERROR + 0x8E))
 #define TPM_CB_RANGE                  ((tpm_result_t) (TPM_CB_ERROR + 0x8F))
+#define TPM_CB_FAIL                   ((tpm_result_t) (TPM_CB_ERROR + 0x90))
+#define TPM_CB_TIMEOUT                ((tpm_result_t) (TPM_CB_ERROR + 0x91))
 
 #endif /* TSS_ERRORS_H_ */
diff --git a/src/security/vboot/antirollback.h b/src/security/vboot/antirollback.h
index ab7c43aac9..c0f77c9fa7 100644
--- a/src/security/vboot/antirollback.h
+++ b/src/security/vboot/antirollback.h
@@ -10,6 +10,7 @@
 
 #include <types.h>
 #include <security/tpm/tspi.h>
+#include <security/tpm/tss_errors.h>
 #include <vb2_sha.h>
 
 struct vb2_context;
@@ -52,23 +53,23 @@ enum vb2_pcr_digest;
 
 /* All functions return TPM_SUCCESS (zero) if successful, non-zero if error */
 
-uint32_t antirollback_read_space_firmware(struct vb2_context *ctx);
+tpm_result_t antirollback_read_space_firmware(struct vb2_context *ctx);
 
 /**
  * Write may be called if the versions change.
  */
-uint32_t antirollback_write_space_firmware(struct vb2_context *ctx);
+tpm_result_t antirollback_write_space_firmware(struct vb2_context *ctx);
 
 /**
  * Read and write kernel space in TPM.
  */
-uint32_t antirollback_read_space_kernel(struct vb2_context *ctx);
-uint32_t antirollback_write_space_kernel(struct vb2_context *ctx);
+tpm_result_t antirollback_read_space_kernel(struct vb2_context *ctx);
+tpm_result_t antirollback_write_space_kernel(struct vb2_context *ctx);
 
 /**
  * Lock must be called.
  */
-uint32_t antirollback_lock_space_firmware(void);
+tpm_result_t antirollback_lock_space_firmware(void);
 
 /*
  * Read MRC hash data from TPM.
@@ -79,7 +80,7 @@ uint32_t antirollback_lock_space_firmware(void);
  * @param data  pointer to buffer where hash from TPM read into
  * @param size  size of buffer
  */
-uint32_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size);
+tpm_result_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size);
 /*
  * Write new hash data to MRC space in TPM.\
  * @param index index into TPM NVRAM where hash is stored The index
@@ -89,7 +90,7 @@ uint32_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_
  * @param data  pointer to buffer of hash value to be written
  * @param size  size of buffer
 */
-uint32_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
+tpm_result_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
 					   uint32_t size);
 /*
  * Lock down MRC hash space in TPM.
@@ -98,19 +99,19 @@ uint32_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
  *              MRC_RW_HASH_NV_INDEX depending upon whether we are
  *              booting in recovery or normal mode.
 */
-uint32_t antirollback_lock_space_mrc_hash(uint32_t index);
+tpm_result_t antirollback_lock_space_mrc_hash(uint32_t index);
 
 /*
  * Read VBIOS hash data from TPM.
  * @param data  pointer to buffer where hash from TPM read into
  * @param size  size of buffer
  */
-uint32_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size);
+tpm_result_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size);
 /*
  * Write new hash data to VBIOS space in TPM.
  * @param data  pointer to buffer of hash value to be written
  * @param size  size of buffer
 */
-uint32_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size);
+tpm_result_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size);
 
 #endif  /* ANTIROLLBACK_H_ */
diff --git a/src/security/vboot/mrc_cache_hash_tpm.c b/src/security/vboot/mrc_cache_hash_tpm.c
index 07baed7eba..d7712a9c5e 100644
--- a/src/security/vboot/mrc_cache_hash_tpm.c
+++ b/src/security/vboot/mrc_cache_hash_tpm.c
@@ -12,10 +12,12 @@
 void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 {
 	struct vb2_hash hash;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Initialize TPM driver. */
-	if (tlcl_lib_init() != VB2_SUCCESS) {
-		printk(BIOS_ERR, "MRC: TPM driver initialization failed.\n");
+	rc = tlcl_lib_init();
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "MRC: TPM driver initialization failed with error %#x.\n", rc);
 		return;
 	}
 
@@ -35,9 +37,9 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 	}
 
 	/* Write hash of data to TPM space. */
-	if (antirollback_write_space_mrc_hash(index, hash.sha256, sizeof(hash.sha256))
-	    != TPM_SUCCESS) {
-		printk(BIOS_ERR, "MRC: Could not save hash to TPM.\n");
+	rc = antirollback_write_space_mrc_hash(index, hash.sha256, sizeof(hash.sha256));
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "MRC: Could not save hash to TPM with error %#x.\n", rc);
 		return;
 	}
 
@@ -47,17 +49,19 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 int mrc_cache_verify_hash(uint32_t index, const uint8_t *data, size_t size)
 {
 	struct vb2_hash tpm_hash = { .algo = VB2_HASH_SHA256 };
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Initialize TPM driver. */
-	if (tlcl_lib_init() != VB2_SUCCESS) {
-		printk(BIOS_ERR, "MRC: TPM driver initialization failed.\n");
+	rc = tlcl_lib_init();
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "MRC: TPM driver initialization failed with error %#x.\n", rc);
 		return 0;
 	}
 
 	/* Read hash of MRC data saved in TPM. */
-	if (antirollback_read_space_mrc_hash(index, tpm_hash.sha256, sizeof(tpm_hash.sha256))
-	    != TPM_SUCCESS) {
-		printk(BIOS_ERR, "MRC: Could not read hash from TPM.\n");
+	rc = antirollback_read_space_mrc_hash(index, tpm_hash.sha256, sizeof(tpm_hash.sha256));
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "MRC: Could not read hash from TPM with error %#x.\n", rc);
 		return 0;
 	}
 
diff --git a/src/security/vboot/secdata_mock.c b/src/security/vboot/secdata_mock.c
index 9d8c13d2ef..83c437da2a 100644
--- a/src/security/vboot/secdata_mock.c
+++ b/src/security/vboot/secdata_mock.c
@@ -6,6 +6,7 @@
  */
 
 #include <security/tpm/tspi.h>
+#include <security/tpm/tss_errors.h>
 #include <vb2_api.h>
 
 #include "antirollback.h"
@@ -15,18 +16,18 @@ vb2_error_t vb2ex_tpm_clear_owner(struct vb2_context *ctx)
 	return VB2_SUCCESS;
 }
 
-vb2_error_t antirollback_read_space_firmware(struct vb2_context *ctx)
+tpm_result_t antirollback_read_space_firmware(struct vb2_context *ctx)
 {
 	vb2api_secdata_firmware_create(ctx);
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_write_space_firmware(struct vb2_context *ctx)
+tpm_result_t antirollback_write_space_firmware(struct vb2_context *ctx)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_read_space_kernel(struct vb2_context *ctx)
+tpm_result_t antirollback_read_space_kernel(struct vb2_context *ctx)
 {
 	/*
 	 * The new kernel secdata v1 stores the last read EC hash, and reboots the
@@ -41,41 +42,41 @@ vb2_error_t antirollback_read_space_kernel(struct vb2_context *ctx)
 	 * v0 device when using MOCK_SECDATA.
 	 */
 	vb2api_secdata_kernel_create_v0(ctx);
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_write_space_kernel(struct vb2_context *ctx)
+tpm_result_t antirollback_write_space_kernel(struct vb2_context *ctx)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_lock_space_firmware(void)
+tpm_result_t antirollback_lock_space_firmware(void)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_lock_space_mrc_hash(uint32_t index)
+tpm_result_t antirollback_lock_space_mrc_hash(uint32_t index)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size)
+tpm_result_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
+tpm_result_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
 					      uint32_t size)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size)
+tpm_result_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
 
-vb2_error_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size)
+tpm_result_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size)
 {
-	return VB2_SUCCESS;
+	return TPM_SUCCESS;
 }
diff --git a/src/security/vboot/secdata_tpm.c b/src/security/vboot/secdata_tpm.c
index d19b47e609..1204be8787 100644
--- a/src/security/vboot/secdata_tpm.c
+++ b/src/security/vboot/secdata_tpm.c
@@ -18,17 +18,17 @@
 	printk(BIOS_INFO, "%s():%d: " format, __func__, __LINE__, ## args)
 
 #define RETURN_ON_FAILURE(tpm_cmd) do {				\
-		uint32_t rc_;					\
+		tpm_result_t rc_;					\
 		if ((rc_ = (tpm_cmd)) != TPM_SUCCESS) {		\
 			VBDEBUG("Antirollback: %08x returned by " #tpm_cmd \
-				 "\n", (int)rc_);			\
+				 "\n", (tpm_result_t)rc_);			\
 			return rc_;					\
 		}							\
 	} while (0)
 
-static uint32_t safe_write(uint32_t index, const void *data, uint32_t length);
+static tpm_result_t safe_write(uint32_t index, const void *data, uint32_t length);
 
-uint32_t antirollback_read_space_kernel(struct vb2_context *ctx)
+tpm_result_t antirollback_read_space_kernel(struct vb2_context *ctx)
 {
 	if (!CONFIG(TPM2)) {
 		/*
@@ -51,7 +51,7 @@ uint32_t antirollback_read_space_kernel(struct vb2_context *ctx)
 	}
 
 	uint8_t size = VB2_SECDATA_KERNEL_SIZE;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	/* Start with the version 1.0 size used by all modern Cr50/Ti50 boards. */
 	rc = tlcl_read(KERNEL_NV_INDEX, ctx->secdata_kernel, size);
@@ -72,7 +72,7 @@ uint32_t antirollback_read_space_kernel(struct vb2_context *ctx)
 
 #if CONFIG(TPM2)
 
-static uint32_t read_space_mrc_hash(uint32_t index, uint8_t *data)
+static tpm_result_t read_space_mrc_hash(uint32_t index, uint8_t *data)
 {
 	RETURN_ON_FAILURE(tlcl_read(index, data,
 				    HASH_NV_SIZE));
@@ -206,7 +206,7 @@ static uint32_t define_space(const char *name, uint32_t index, uint32_t length,
 			     const TPMA_NV nv_attributes,
 			     const uint8_t *nv_policy, size_t nv_policy_size)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = tlcl_define_space(index, length, nv_attributes, nv_policy,
 			       nv_policy_size);
@@ -227,16 +227,16 @@ static uint32_t define_space(const char *name, uint32_t index, uint32_t length,
 }
 
 /* Nothing special in the TPM2 path yet. */
-static uint32_t safe_write(uint32_t index, const void *data, uint32_t length)
+static tpm_result_t safe_write(uint32_t index, const void *data, uint32_t length)
 {
 	return tlcl_write(index, data, length);
 }
 
-static uint32_t setup_space(const char *name, uint32_t index, const void *data,
-			    uint32_t length, const TPMA_NV nv_attributes,
-			    const uint8_t *nv_policy, size_t nv_policy_size)
+static tpm_result_t setup_space(const char *name, uint32_t index, const void *data,
+				uint32_t length, const TPMA_NV nv_attributes,
+				const uint8_t *nv_policy, size_t nv_policy_size)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = define_space(name, index, length, nv_attributes, nv_policy,
 			  nv_policy_size);
@@ -246,7 +246,7 @@ static uint32_t setup_space(const char *name, uint32_t index, const void *data,
 	return safe_write(index, data, length);
 }
 
-static uint32_t setup_firmware_space(struct vb2_context *ctx)
+static tpm_result_t setup_firmware_space(struct vb2_context *ctx)
 {
 	uint32_t firmware_space_size = vb2api_secdata_firmware_create(ctx);
 
@@ -256,7 +256,7 @@ static uint32_t setup_firmware_space(struct vb2_context *ctx)
 			   sizeof(pcr0_allowed_policy));
 }
 
-static uint32_t setup_fwmp_space(struct vb2_context *ctx)
+static tpm_result_t setup_fwmp_space(struct vb2_context *ctx)
 {
 	uint32_t fwmp_space_size = vb2api_secdata_fwmp_create(ctx);
 
@@ -264,7 +264,7 @@ static uint32_t setup_fwmp_space(struct vb2_context *ctx)
 			   fwmp_attr, NULL, 0);
 }
 
-static uint32_t setup_kernel_space(struct vb2_context *ctx)
+static tpm_result_t setup_kernel_space(struct vb2_context *ctx)
 {
 	uint32_t kernel_space_size = vb2api_secdata_kernel_create(ctx);
 
@@ -272,7 +272,7 @@ static uint32_t setup_kernel_space(struct vb2_context *ctx)
 			    kernel_space_size, rw_space_attributes, NULL, 0);
 }
 
-static uint32_t set_mrc_hash_space(uint32_t index, const uint8_t *data)
+static tpm_result_t set_mrc_hash_space(uint32_t index, const uint8_t *data)
 {
 	if (index == MRC_REC_HASH_NV_INDEX) {
 		return setup_space("RO MRC Hash", index, data, HASH_NV_SIZE,
@@ -289,9 +289,9 @@ static uint32_t set_mrc_hash_space(uint32_t index, const uint8_t *data)
  *
  * These spaces are not used by firmware, but we do need to initialize them.
  */
-static uint32_t setup_zte_spaces(void)
+static tpm_result_t setup_zte_spaces(void)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 	uint64_t rma_bytes_counter_default = 0;
 	uint8_t rma_sn_bits_default[16];
 	uint8_t board_id_default[12];
@@ -307,7 +307,7 @@ static uint32_t setup_zte_spaces(void)
 			 zte_attr,
 			 unsatisfiable_policy, sizeof(unsatisfiable_policy));
 	if (rc != TPM_SUCCESS) {
-		VBDEBUG("%s: Failed to set up RMA + SN Bits space\n", __func__);
+		VBDEBUG("%s: Failed to set up RMA + SN Bits space with error %#x\n", __func__, rc);
 		return rc;
 	}
 
@@ -316,7 +316,7 @@ static uint32_t setup_zte_spaces(void)
 			 zte_attr,
 			 unsatisfiable_policy, sizeof(unsatisfiable_policy));
 	if (rc != TPM_SUCCESS) {
-		VBDEBUG("%s: Failed to set up Board ID space\n", __func__);
+		VBDEBUG("%s: Failed to set up Board ID space with error %#x\n", __func__, rc);
 		return rc;
 	}
 
@@ -326,7 +326,7 @@ static uint32_t setup_zte_spaces(void)
 			  zte_rma_bytes_attr,
 			  unsatisfiable_policy, sizeof(unsatisfiable_policy));
 	if (rc != TPM_SUCCESS) {
-		VBDEBUG("%s: Failed to define RMA Bytes space\n", __func__);
+		VBDEBUG("%s: Failed to define RMA Bytes space with error %#x\n", __func__, rc);
 		return rc;
 	}
 
@@ -337,8 +337,8 @@ static uint32_t setup_zte_spaces(void)
 	rc = tlcl_set_bits(ZTE_RMA_BYTES_COUNTER_INDEX,
 			   rma_bytes_counter_default);
 	if (rc != TPM_SUCCESS) {
-		VBDEBUG("%s: Failed to init RMA Bytes counter space\n",
-			__func__);
+		VBDEBUG("%s: Failed to init RMA Bytes counter space wit error %#x\n",
+			__func__, rc);
 		return rc;
 	}
 
@@ -351,7 +351,7 @@ static uint32_t setup_zte_spaces(void)
  * This space is not used by firmware but needs to survive owner clear. Thus, it
  * needs to be created here.
  */
-static uint32_t enterprise_rollback_create_space(void)
+static tpm_result_t enterprise_rollback_create_space(void)
 {
 	uint8_t rollback_space_default[32] = {0};
 
@@ -361,9 +361,10 @@ static uint32_t enterprise_rollback_create_space(void)
 			   unsatisfiable_policy, sizeof(unsatisfiable_policy));
 }
 
-static uint32_t setup_widevine_counter_spaces(void)
+static tpm_result_t setup_widevine_counter_spaces(void)
 {
-	uint32_t index, rc;
+	uint32_t index;
+	tpm_result_t rc;
 
 	for (index = 0; index < NUM_WIDEVINE_COUNTERS; index++) {
 		rc = define_space(WIDEVINE_COUNTER_NAME,
@@ -375,10 +376,10 @@ static uint32_t setup_widevine_counter_spaces(void)
 		if (rc != TPM_SUCCESS)
 			return rc;
 	}
-	return TPM_SUCCESS;
+	return rc;
 }
 
-static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
+static tpm_result_t _factory_initialize_tpm(struct vb2_context *ctx)
 {
 	RETURN_ON_FAILURE(tlcl_force_clear());
 
@@ -428,12 +429,12 @@ static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
 	return TPM_SUCCESS;
 }
 
-uint32_t antirollback_lock_space_firmware(void)
+tpm_result_t antirollback_lock_space_firmware(void)
 {
 	return tlcl_lock_nv_write(FIRMWARE_NV_INDEX);
 }
 
-uint32_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size)
+tpm_result_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size)
 {
 	if (size != HASH_NV_SIZE) {
 		VBDEBUG("TPM: Incorrect buffer size for hash idx %#x. "
@@ -444,10 +445,10 @@ uint32_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_
 	return read_space_mrc_hash(index, data);
 }
 
-uint32_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data, uint32_t size)
+tpm_result_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data, uint32_t size)
 {
 	uint8_t spc_data[HASH_NV_SIZE];
-	uint32_t rc;
+	tpm_result_t rc;
 
 	if (size != HASH_NV_SIZE) {
 		VBDEBUG("TPM: Incorrect buffer size for hash idx %#x. "
@@ -472,18 +473,18 @@ uint32_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
 	return safe_write(index, data, size);
 }
 
-uint32_t antirollback_lock_space_mrc_hash(uint32_t index)
+tpm_result_t antirollback_lock_space_mrc_hash(uint32_t index)
 {
 	return tlcl_lock_nv_write(index);
 }
 
-static uint32_t read_space_vbios_hash(uint8_t *data)
+static tpm_result_t read_space_vbios_hash(uint8_t *data)
 {
 	RETURN_ON_FAILURE(tlcl_read(VBIOS_CACHE_NV_INDEX, data, HASH_NV_SIZE));
 	return TPM_SUCCESS;
 }
 
-uint32_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size)
+tpm_result_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size)
 {
 	if (size != HASH_NV_SIZE) {
 		VBDEBUG("TPM: Incorrect buffer size for hash idx %#x. "
@@ -494,10 +495,10 @@ uint32_t antirollback_read_space_vbios_hash(uint8_t *data, uint32_t size)
 	return read_space_vbios_hash(data);
 }
 
-uint32_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size)
+tpm_result_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size)
 {
 	uint8_t spc_data[HASH_NV_SIZE];
-	uint32_t rc;
+	tpm_result_t rc;
 
 	if (size != HASH_NV_SIZE) {
 		VBDEBUG("TPM: Incorrect buffer size for hash idx %#x. "
@@ -532,9 +533,9 @@ uint32_t antirollback_write_space_vbios_hash(const uint8_t *data, uint32_t size)
  * This is not expected to happen frequently, but it could happen.
  */
 
-static uint32_t safe_write(uint32_t index, const void *data, uint32_t length)
+static tpm_result_t safe_write(uint32_t index, const void *data, uint32_t length)
 {
-	uint32_t rc = tlcl_write(index, data, length);
+	tpm_result_t rc = tlcl_write(index, data, length);
 	if (rc == TPM_MAXNVWRITES) {
 		RETURN_ON_FAILURE(tpm_clear_and_reenable());
 		return tlcl_write(index, data, length);
@@ -549,9 +550,9 @@ static uint32_t safe_write(uint32_t index, const void *data, uint32_t length)
  * writes because we only define spaces once at initialization, but we'd
  * rather be paranoid about this.
  */
-static uint32_t safe_define_space(uint32_t index, uint32_t perm, uint32_t size)
+static tpm_result_t safe_define_space(uint32_t index, uint32_t perm, uint32_t size)
 {
-	uint32_t rc = tlcl_define_space(index, perm, size);
+	tpm_result_t rc = tlcl_define_space(index, perm, size);
 	if (rc == TPM_MAXNVWRITES) {
 		RETURN_ON_FAILURE(tpm_clear_and_reenable());
 		return tlcl_define_space(index, perm, size);
@@ -560,10 +561,10 @@ static uint32_t safe_define_space(uint32_t index, uint32_t perm, uint32_t size)
 	}
 }
 
-static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
+static tpm_result_t _factory_initialize_tpm(struct vb2_context *ctx)
 {
 	TPM_PERMANENT_FLAGS pflags;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	vb2api_secdata_firmware_create(ctx);
 	vb2api_secdata_kernel_create_v0(ctx);
@@ -618,7 +619,7 @@ static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
 	return TPM_SUCCESS;
 }
 
-uint32_t antirollback_lock_space_firmware(void)
+tpm_result_t antirollback_lock_space_firmware(void)
 {
 	return tlcl_set_global_lock();
 }
@@ -632,9 +633,9 @@ uint32_t antirollback_lock_space_firmware(void)
  * nvLocked bit and ensures the physical presence command is enabled and
  * locked.
  */
-static uint32_t factory_initialize_tpm(struct vb2_context *ctx)
+static tpm_result_t factory_initialize_tpm(struct vb2_context *ctx)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	VBDEBUG("TPM: factory initialization\n");
 
@@ -664,9 +665,9 @@ static uint32_t factory_initialize_tpm(struct vb2_context *ctx)
 	return TPM_SUCCESS;
 }
 
-uint32_t antirollback_read_space_firmware(struct vb2_context *ctx)
+tpm_result_t antirollback_read_space_firmware(struct vb2_context *ctx)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = tlcl_read(FIRMWARE_NV_INDEX, ctx->secdata_firmware, VB2_SECDATA_FIRMWARE_SIZE);
 	if (rc == TPM_BADINDEX) {
@@ -678,10 +679,10 @@ uint32_t antirollback_read_space_firmware(struct vb2_context *ctx)
 		return TPM_CB_CORRUPTED_STATE;
 	}
 
-	return TPM_SUCCESS;
+	return rc;
 }
 
-uint32_t antirollback_write_space_firmware(struct vb2_context *ctx)
+tpm_result_t antirollback_write_space_firmware(struct vb2_context *ctx)
 {
 	if (CONFIG(TPM_GOOGLE_IMMEDIATELY_COMMIT_FW_SECDATA))
 		tlcl_cr50_enable_nvcommits();
@@ -689,7 +690,7 @@ uint32_t antirollback_write_space_firmware(struct vb2_context *ctx)
 			  VB2_SECDATA_FIRMWARE_SIZE);
 }
 
-uint32_t antirollback_write_space_kernel(struct vb2_context *ctx)
+tpm_result_t antirollback_write_space_kernel(struct vb2_context *ctx)
 {
 	/* Learn the expected size. */
 	uint8_t size = VB2_SECDATA_KERNEL_MIN_SIZE;
@@ -710,10 +711,6 @@ uint32_t antirollback_write_space_kernel(struct vb2_context *ctx)
 
 vb2_error_t vb2ex_tpm_clear_owner(struct vb2_context *ctx)
 {
-	uint32_t rc;
 	printk(BIOS_INFO, "Clearing TPM owner\n");
-	rc = tpm_clear_and_reenable();
-	if (rc)
-		return VB2_ERROR_EX_TPM_CLEAR_OWNER;
-	return VB2_SUCCESS;
+	return tpm_clear_and_reenable() == TPM_SUCCESS ? VB2_SUCCESS : VB2_ERROR_EX_TPM_CLEAR_OWNER;
 }
diff --git a/src/security/vboot/tpm_common.c b/src/security/vboot/tpm_common.c
index a2e9bb45cd..c330cc2dcd 100644
--- a/src/security/vboot/tpm_common.c
+++ b/src/security/vboot/tpm_common.c
@@ -2,6 +2,7 @@
 
 #include <security/tpm/tspi.h>
 #include <security/vboot/tpm_common.h>
+#include <security/tpm/tss_errors.h>
 #include <vb2_api.h>
 #include <vb2_sha.h>
 
@@ -9,9 +10,9 @@
 #define TPM_PCR_GBB_HWID_NAME "VBOOT: GBB HWID"
 #define TPM_PCR_MINIMUM_DIGEST_SIZE 20
 
-uint32_t vboot_setup_tpm(struct vb2_context *ctx)
+tpm_result_t vboot_setup_tpm(struct vb2_context *ctx)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = tpm_setup(ctx->flags & VB2_CONTEXT_S3_RESUME);
 	if (rc == TPM_CB_MUST_REBOOT)
@@ -20,16 +21,14 @@ uint32_t vboot_setup_tpm(struct vb2_context *ctx)
 	return rc;
 }
 
-vb2_error_t vboot_extend_pcr(struct vb2_context *ctx, int pcr,
+tpm_result_t vboot_extend_pcr(struct vb2_context *ctx, int pcr,
 			     enum vb2_pcr_digest which_digest)
 {
 	uint8_t buffer[VB2_PCR_DIGEST_RECOMMENDED_SIZE];
 	uint32_t size = sizeof(buffer);
-	vb2_error_t rv;
 
-	rv = vb2api_get_pcr_digest(ctx, which_digest, buffer, &size);
-	if (rv != VB2_SUCCESS)
-		return rv;
+	if (vb2api_get_pcr_digest(ctx, which_digest, buffer, &size) != VB2_SUCCESS)
+		return TPM_CB_FAIL;
 
 	/*
 	 * On TPM 1.2, all PCRs are intended for use with SHA1. We truncate our
@@ -56,6 +55,6 @@ vb2_error_t vboot_extend_pcr(struct vb2_context *ctx, int pcr,
 		return tpm_extend_pcr(pcr, algo, buffer, vb2_digest_size(algo),
 				      TPM_PCR_GBB_HWID_NAME);
 	default:
-		return VB2_ERROR_UNKNOWN;
+		return TPM_CB_FAIL;
 	}
 }
diff --git a/src/security/vboot/tpm_common.h b/src/security/vboot/tpm_common.h
index 7c440f52d2..22ece8927b 100644
--- a/src/security/vboot/tpm_common.h
+++ b/src/security/vboot/tpm_common.h
@@ -3,16 +3,16 @@
 #if CONFIG(TPM)
 
 /* Start of the root of trust */
-uint32_t vboot_setup_tpm(struct vb2_context *ctx);
+tpm_result_t vboot_setup_tpm(struct vb2_context *ctx);
 
 /* vboot_extend_pcr function for vb2 context */
-vb2_error_t vboot_extend_pcr(struct vb2_context *ctx, int pcr,
+tpm_result_t vboot_extend_pcr(struct vb2_context *ctx, int pcr,
 			     enum vb2_pcr_digest which_digest);
 
 #else
 
-#define vboot_setup_tpm(ctx) 0
+#define vboot_setup_tpm(ctx) TPM_SUCCESS
 
-#define vboot_extend_pcr(ctx, pcr, which_digest) 0
+#define vboot_extend_pcr(ctx, pcr, which_digest) TPM_SUCCESS
 
 #endif
diff --git a/src/security/vboot/vbios_cache_hash_tpm.c b/src/security/vboot/vbios_cache_hash_tpm.c
index 6ad09ace8e..49971350f1 100644
--- a/src/security/vboot/vbios_cache_hash_tpm.c
+++ b/src/security/vboot/vbios_cache_hash_tpm.c
@@ -12,10 +12,12 @@
 void vbios_cache_update_hash(const uint8_t *data, size_t size)
 {
 	struct vb2_hash hash;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Initialize TPM driver. */
-	if (tlcl_lib_init() != VB2_SUCCESS) {
-		printk(BIOS_ERR, "VBIOS_CACHE: TPM driver initialization failed.\n");
+	rc = tlcl_lib_init();
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "VBIOS_CACHE: TPM driver initialization failed with error %#x.\n", rc);
 		return;
 	}
 
@@ -35,9 +37,9 @@ void vbios_cache_update_hash(const uint8_t *data, size_t size)
 	}
 
 	/* Write hash of data to TPM space. */
-	if (antirollback_write_space_vbios_hash(hash.sha256, sizeof(hash.sha256))
-			!= TPM_SUCCESS) {
-		printk(BIOS_ERR, "VBIOS_CACHE: Could not save hash to TPM.\n");
+	rc = antirollback_write_space_vbios_hash(hash.sha256, sizeof(hash.sha256));
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "VBIOS_CACHE: Could not save hash to TPM with error %#x.\n", rc);
 		return;
 	}
 
@@ -48,17 +50,19 @@ void vbios_cache_update_hash(const uint8_t *data, size_t size)
 enum cb_err vbios_cache_verify_hash(const uint8_t *data, size_t size)
 {
 	struct vb2_hash tpm_hash = { .algo = VB2_HASH_SHA256 };
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Initialize TPM driver. */
-	if (tlcl_lib_init() != VB2_SUCCESS) {
-		printk(BIOS_ERR, "VBIOS_CACHE: TPM driver initialization failed.\n");
+	rc = tlcl_lib_init();
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "VBIOS_CACHE: TPM driver initialization failed with error %#x.\n", rc);
 		return CB_ERR;
 	}
 
 	/* Read hash of VBIOS data saved in TPM. */
-	if (antirollback_read_space_vbios_hash(tpm_hash.sha256,	sizeof(tpm_hash.sha256))
-			!= TPM_SUCCESS) {
-		printk(BIOS_ERR, "VBIOS_CACHE: Could not read hash from TPM.\n");
+	rc = antirollback_read_space_vbios_hash(tpm_hash.sha256,	sizeof(tpm_hash.sha256));
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "VBIOS_CACHE: Could not read hash from TPM with error %#x.\n", rc);
 		return CB_ERR;
 	}
 
diff --git a/src/security/vboot/vboot_common.c b/src/security/vboot/vboot_common.c
index 3c4957a7ed..f9080c585a 100644
--- a/src/security/vboot/vboot_common.c
+++ b/src/security/vboot/vboot_common.c
@@ -2,6 +2,7 @@
 
 #include <console/cbmem_console.h>
 #include <reset.h>
+#include <security/tpm/tss_errors.h>
 #include <security/vboot/misc.h>
 #include <security/vboot/vboot_common.h>
 #include <security/vboot/vbnv.h>
@@ -12,14 +13,14 @@
 static void save_secdata(struct vb2_context *ctx)
 {
 	if (ctx->flags & VB2_CONTEXT_SECDATA_FIRMWARE_CHANGED
-	    && (CONFIG(VBOOT_MOCK_SECDATA) || tlcl_lib_init() == VB2_SUCCESS)) {
+	    && (CONFIG(VBOOT_MOCK_SECDATA) || tlcl_lib_init() == TPM_SUCCESS)) {
 		printk(BIOS_INFO, "Saving secdata firmware\n");
 		antirollback_write_space_firmware(ctx);
 		ctx->flags &= ~VB2_CONTEXT_SECDATA_FIRMWARE_CHANGED;
 	}
 
 	if (ctx->flags & VB2_CONTEXT_SECDATA_KERNEL_CHANGED
-	    && (CONFIG(VBOOT_MOCK_SECDATA) || tlcl_lib_init() == VB2_SUCCESS)) {
+	    && (CONFIG(VBOOT_MOCK_SECDATA) || tlcl_lib_init() == TPM_SUCCESS)) {
 		printk(BIOS_INFO, "Saving secdata kernel\n");
 		antirollback_write_space_kernel(ctx);
 		ctx->flags &= ~VB2_CONTEXT_SECDATA_KERNEL_CHANGED;
diff --git a/src/security/vboot/vboot_logic.c b/src/security/vboot/vboot_logic.c
index f6d8bad2e3..ab38085f48 100644
--- a/src/security/vboot/vboot_logic.c
+++ b/src/security/vboot/vboot_logic.c
@@ -7,6 +7,7 @@
 #include <fmap.h>
 #include <security/tpm/tspi/crtm.h>
 #include <security/tpm/tss/vendor/cr50/cr50.h>
+#include <security/tpm/tss_errors.h>
 #include <security/vboot/misc.h>
 #include <security/vboot/vbnv.h>
 #include <security/vboot/tpm_common.h>
@@ -182,12 +183,12 @@ static vb2_error_t hash_body(struct vb2_context *ctx,
 	return handle_digest_result(hash_digest, hash_digest_sz);
 }
 
-static vb2_error_t extend_pcrs(struct vb2_context *ctx)
+static tpm_result_t extend_pcrs(struct vb2_context *ctx)
 {
-	vb2_error_t rv;
-	rv = vboot_extend_pcr(ctx, CONFIG_PCR_BOOT_MODE, BOOT_MODE_PCR);
-	if (rv)
-		return rv;
+	tpm_result_t rc;
+	rc = vboot_extend_pcr(ctx, CONFIG_PCR_BOOT_MODE, BOOT_MODE_PCR);
+	if (rc)
+		return rc;
 	return vboot_extend_pcr(ctx, CONFIG_PCR_HWID, HWID_DIGEST_PCR);
 }
 
@@ -210,7 +211,7 @@ static const char *get_boot_mode_string(uint8_t boot_mode)
 static void check_boot_mode(struct vb2_context *ctx)
 {
 	uint8_t boot_mode;
-	int rc;
+	tpm_result_t rc;
 
 	rc = tlcl_cr50_get_boot_mode(&boot_mode);
 	switch (rc) {
@@ -222,7 +223,7 @@ static void check_boot_mode(struct vb2_context *ctx)
 		break;
 	default:
 		printk(BIOS_ERR,
-		       "Communication error in getting GSC boot mode.\n");
+		       "Communication error(%#x) in getting GSC boot mode.\n", rc);
 		vb2api_fail(ctx, VB2_RECOVERY_GSC_BOOT_MODE, rc);
 		return;
 	}
@@ -240,6 +241,7 @@ static void check_boot_mode(struct vb2_context *ctx)
 void verstage_main(void)
 {
 	struct vb2_context *ctx;
+	tpm_result_t tpm_rc;
 	vb2_error_t rv;
 
 	timestamp_add_now(TS_VBOOT_START);
@@ -363,10 +365,13 @@ void verstage_main(void)
 	/* Only extend PCRs once on boot. */
 	if (!(ctx->flags & VB2_CONTEXT_S3_RESUME)) {
 		timestamp_add_now(TS_TPMPCR_START);
-		rv = extend_pcrs(ctx);
-		if (rv) {
-			printk(BIOS_WARNING, "Failed to extend TPM PCRs (%#x)\n", rv);
-			vboot_fail_and_reboot(ctx, VB2_RECOVERY_RO_TPM_U_ERROR, rv);
+		tpm_rc = extend_pcrs(ctx);
+		if (tpm_rc) {
+			printk(BIOS_WARNING, "Failed to extend TPM PCRs (%#x)\n",
+				tpm_rc);
+			vboot_fail_and_reboot(ctx,
+				VB2_RECOVERY_RO_TPM_U_ERROR,
+				tpm_rc);
 		}
 		timestamp_add_now(TS_TPMPCR_END);
 	}
@@ -374,19 +379,21 @@ void verstage_main(void)
 	/* Lock TPM */
 
 	timestamp_add_now(TS_TPMLOCK_START);
-	rv = antirollback_lock_space_firmware();
-	if (rv) {
-		printk(BIOS_INFO, "Failed to lock TPM (%#x)\n", rv);
+	tpm_rc = antirollback_lock_space_firmware();
+	if (tpm_rc) {
+		printk(BIOS_INFO, "Failed to lock TPM (%#x)\n", tpm_rc);
 		vboot_fail_and_reboot(ctx, VB2_RECOVERY_RO_TPM_L_ERROR, 0);
 	}
 	timestamp_add_now(TS_TPMLOCK_END);
 
 	/* Lock rec hash space if available. */
 	if (CONFIG(VBOOT_HAS_REC_HASH_SPACE)) {
-		rv = antirollback_lock_space_mrc_hash(MRC_REC_HASH_NV_INDEX);
-		if (rv) {
-			printk(BIOS_INFO, "Failed to lock rec hash space(%#x)\n", rv);
-			vboot_fail_and_reboot(ctx, VB2_RECOVERY_RO_TPM_REC_HASH_L_ERROR, rv);
+		tpm_rc = antirollback_lock_space_mrc_hash(
+				MRC_REC_HASH_NV_INDEX);
+		if (tpm_rc) {
+			printk(BIOS_INFO, "Failed to lock rec hash space(%#x)\n",
+				tpm_rc);
+			vboot_fail_and_reboot(ctx, VB2_RECOVERY_RO_TPM_REC_HASH_L_ERROR, tpm_rc);
 		}
 	}
 
diff --git a/src/soc/amd/common/psp_verstage/psp_verstage.c b/src/soc/amd/common/psp_verstage/psp_verstage.c
index c9058192d3..87d126f228 100644
--- a/src/soc/amd/common/psp_verstage/psp_verstage.c
+++ b/src/soc/amd/common/psp_verstage/psp_verstage.c
@@ -208,7 +208,7 @@ static uint32_t save_buffers(void)
  */
 static void psp_verstage_s0i3_resume(void)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	post_code(POSTCODE_VERSTAGE_S0I3_RESUME);
 
diff --git a/src/vendorcode/eltan/security/mboot/mboot.c b/src/vendorcode/eltan/security/mboot/mboot.c
index 783f587323..b456d2633b 100644
--- a/src/vendorcode/eltan/security/mboot/mboot.c
+++ b/src/vendorcode/eltan/security/mboot/mboot.c
@@ -13,7 +13,7 @@
  */
 EFI_TCG2_EVENT_ALGORITHM_BITMAP tpm2_get_active_pcrs(void)
 {
-	int rc;
+	tpm_result_t rc;
 	TPML_PCR_SELECTION Pcrs;
 	EFI_TCG2_EVENT_ALGORITHM_BITMAP tpmHashAlgorithmBitmap = 0;
 	uint32_t activePcrBanks = 0;
@@ -75,10 +75,10 @@ EFI_TCG2_EVENT_ALGORITHM_BITMAP tpm2_get_active_pcrs(void)
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		The command was unsuccessful.
  */
-int tpm2_get_capability_pcrs(TPML_PCR_SELECTION *Pcrs)
+tpm_result_t tpm2_get_capability_pcrs(TPML_PCR_SELECTION *Pcrs)
 {
 	TPMS_CAPABILITY_DATA TpmCap;
-	int rc;
+	tpm_result_t rc;
 	int index;
 
 	rc = tlcl_get_capability(TPM_CAP_PCRS, 0, 1, &TpmCap);
@@ -115,7 +115,7 @@ int tpm2_get_capability_pcrs(TPML_PCR_SELECTION *Pcrs)
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		Unexpected device behavior.
  */
-int mboot_hash_extend_log(uint64_t flags, uint8_t *hashData, uint32_t hashDataLen,
+tpm_result_t mboot_hash_extend_log(uint64_t flags, uint8_t *hashData, uint32_t hashDataLen,
 	TCG_PCR_EVENT2_HDR *newEventHdr, uint8_t *eventLog)
 {
 	TPMT_HA *digest = NULL;
@@ -149,7 +149,7 @@ int mboot_hash_extend_log(uint64_t flags, uint8_t *hashData, uint32_t hashDataLe
 void invalidate_pcrs(void)
 {
 	int pcr;
-	int rc;
+	tpm_result_t rc;
 
 	TCG_PCR_EVENT2_HDR tcgEventHdr;
 	uint8_t invalidate = 1;
@@ -227,10 +227,9 @@ void mboot_print_buffer(uint8_t *buffer, uint32_t bufferSize)
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		Unexpected device behavior.
  */
-int mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
+tpm_result_t mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
 			  TCG_EVENTTYPE eventType, const char *event_msg)
 {
-	int rc;
 	TCG_PCR_EVENT2_HDR tcgEventHdr;
 	uint8_t *base;
 	size_t size;
@@ -240,7 +239,7 @@ int mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
 
 	if (base == NULL) {
 		printk(BIOS_DEBUG, "%s: CBFS locate fail: %s\n", __func__, name);
-		return VB2_ERROR_READ_FILE_OPEN;
+		return TPM_IOERROR;
 	}
 
 	printk(BIOS_DEBUG, "%s: CBFS locate success: %s\n", __func__, name);
@@ -250,8 +249,7 @@ int mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
 	if (event_msg)
 		tcgEventHdr.eventSize = (uint32_t) strlen(event_msg);
 
-	rc = mboot_hash_extend_log(0, base, size, &tcgEventHdr, (uint8_t *)event_msg);
-	return rc;
+	return mboot_hash_extend_log(0, base, size, &tcgEventHdr, (uint8_t *)event_msg);
 }
 
 /*
@@ -271,15 +269,17 @@ int mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
  * @retval TPM_IOERROR		Unexpected device behavior.
 **/
 
-__weak int mb_entry(int wake_from_s3)
+__weak tpm_result_t mb_entry(int wake_from_s3)
 {
-	int rc;
+	tpm_result_t rc;
 
 	/* Initialize TPM driver. */
 	printk(BIOS_DEBUG, "%s: tlcl_lib_init\n", __func__);
-	if (tlcl_lib_init() != VB2_SUCCESS) {
-		printk(BIOS_ERR, "%s: TPM driver initialization failed.\n", __func__);
-		return TPM_IOERROR;
+	rc = tlcl_lib_init();
+	if (rc != TPM_SUCCESS) {
+		printk(BIOS_ERR, "%s: TPM driver initialization failed with error %#x.\n",
+			__func__, rc);
+		return rc;
 	}
 
 	if (wake_from_s3) {
@@ -315,9 +315,9 @@ __weak int mb_entry(int wake_from_s3)
  * @retval TPM_IOERROR		Unexpected device behavior.
  */
 
-__weak int mb_measure(int wake_from_s3)
+__weak tpm_result_t mb_measure(int wake_from_s3)
 {
-	uint32_t rc;
+	tpm_result_t rc;
 
 	rc = mb_entry(wake_from_s3);
 	if (rc == TPM_SUCCESS) {
@@ -357,9 +357,9 @@ __weak int mb_measure(int wake_from_s3)
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		Unexpected device behavior.
  */
-__weak int mb_measure_log_start(void)
+__weak tpm_result_t mb_measure_log_start(void)
 {
-	int rc;
+	tpm_result_t rc;
 	uint32_t i;
 
 	if ((tpm2_get_active_pcrs() & EFI_TCG2_BOOT_HASH_ALG_SHA256) == 0x0) {
@@ -369,9 +369,9 @@ __weak int mb_measure_log_start(void)
 	}
 
 	rc = mb_crtm();
-	if (rc != TPM_SUCCESS) {
+	if (rc) {
 		printk(BIOS_DEBUG, "%s: Fail! CRTM Version can't be measured."
-			" ABORTING!!!\n", __func__);
+			" Received error %#x, ABORTING!!!\n", __func__, rc);
 		return rc;
 	}
 	printk(BIOS_DEBUG, "%s: Success! CRTM Version measured.\n", __func__);
@@ -414,9 +414,9 @@ static const uint8_t crtm_version[] =
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		Unexpected device behavior.
 **/
-__weak int mb_crtm(void)
+__weak tpm_result_t mb_crtm(void)
 {
-	int rc;
+	tpm_result_t rc;
 	TCG_PCR_EVENT2_HDR tcgEventHdr;
 	uint8_t hash[VB2_SHA256_DIGEST_SIZE];
 	uint8_t *msgPtr;
diff --git a/src/vendorcode/eltan/security/mboot/mboot.h b/src/vendorcode/eltan/security/mboot/mboot.h
index 9d906abf47..20333fc1b1 100644
--- a/src/vendorcode/eltan/security/mboot/mboot.h
+++ b/src/vendorcode/eltan/security/mboot/mboot.h
@@ -76,12 +76,12 @@ typedef uint32_t EFI_TCG2_EVENT_ALGORITHM_BITMAP;
 
 int is_zero_buffer(void *buffer, unsigned int size);
 
-int mboot_hash_extend_log(uint64_t flags, uint8_t *hashData, uint32_t hashDataLen,
+tpm_result_t mboot_hash_extend_log(uint64_t flags, uint8_t *hashData, uint32_t hashDataLen,
 			  TCG_PCR_EVENT2_HDR *newEventHdr, uint8_t *eventLog);
 
 void mboot_print_buffer(uint8_t *buffer, uint32_t bufferSize);
 
-int mb_crtm(void);
+tpm_result_t mb_crtm(void);
 
 typedef struct {
 	const char *cbfs_name;
@@ -91,18 +91,18 @@ typedef struct {
 	const char *event_msg;
 } mboot_measure_item_t;
 
-int mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
+tpm_result_t mb_measure_log_worker(const char *name, uint32_t type, uint32_t pcr,
 			  TCG_EVENTTYPE eventType, const char *event_msg);
 
-int mb_measure_log_start(void);
+tpm_result_t mb_measure_log_start(void);
 void invalidate_pcrs(void);
 
 EFI_TCG2_EVENT_ALGORITHM_BITMAP tpm2_get_active_pcrs(void);
 
-int tpm2_get_capability_pcrs(TPML_PCR_SELECTION *Pcrs);
+tpm_result_t tpm2_get_capability_pcrs(TPML_PCR_SELECTION *Pcrs);
 
-int mb_measure(int wake_from_s3);
-int mb_entry(int wake_from_s3);
+tpm_result_t mb_measure(int wake_from_s3);
+tpm_result_t mb_entry(int wake_from_s3);
 
 int log_efi_specid_event(void);
 int log_event_tcg_20_format(TCG_PCR_EVENT2_HDR *EventHdr, uint8_t *EventLog);
diff --git a/src/vendorcode/eltan/security/verified_boot/vboot_check.c b/src/vendorcode/eltan/security/verified_boot/vboot_check.c
index 9ea31b877c..9d610064c4 100644
--- a/src/vendorcode/eltan/security/verified_boot/vboot_check.c
+++ b/src/vendorcode/eltan/security/verified_boot/vboot_check.c
@@ -5,6 +5,7 @@
 #include <bootmode.h>
 #include <cbfs.h>
 #include <fmap_config.h>
+#include <security/tpm/tss_errors.h>
 #include <vboot_check.h>
 #include <vboot_common.h>
 #include <vb2_internals_please_do_not_use.h>
@@ -115,24 +116,24 @@ fail:
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_IOERROR		Unexpected device behavior.
  */
-static int measure_item(uint32_t pcr, uint8_t *hashData, uint32_t hashDataLen,
+static tpm_result_t measure_item(uint32_t pcr, uint8_t *hashData, uint32_t hashDataLen,
 		int8_t *event_msg, TCG_EVENTTYPE eventType)
 {
-	int status = TPM_SUCCESS;
+	tpm_result_t rc = TPM_SUCCESS;
 	TCG_PCR_EVENT2_HDR tcgEventHdr;
 
 	memset(&tcgEventHdr, 0, sizeof(tcgEventHdr));
 	tcgEventHdr.pcrIndex = pcr;
 	tcgEventHdr.eventType = eventType;
 	if (event_msg) {
-		status = mboot_hash_extend_log(MBOOT_HASH_PROVIDED, hashData,
+		rc = mboot_hash_extend_log(MBOOT_HASH_PROVIDED, hashData,
 					       hashDataLen, &tcgEventHdr,
 					       (uint8_t *)event_msg);
-		if (status == TPM_SUCCESS)
+		if (rc == TPM_SUCCESS)
 			printk(BIOS_INFO, "%s: Success! %s measured to pcr %d.\n", __func__,
 			       event_msg, pcr);
 	}
-	return status;
+	return rc;
 }
 
 static void verified_boot_check_buffer(const char *name, void *start, size_t size,
@@ -140,6 +141,7 @@ static void verified_boot_check_buffer(const char *name, void *start, size_t siz
 {
 	uint8_t  digest[DIGEST_SIZE];
 	vb2_error_t status;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	printk(BIOS_DEBUG, "%s: %s HASH verification buffer %p size %d\n", __func__, name,
 	       start, (int)size);
@@ -166,10 +168,11 @@ static void verified_boot_check_buffer(const char *name, void *start, size_t siz
 				if (pcr != -1) {
 					printk(BIOS_DEBUG, "%s: measuring %s\n", __func__,
 					       name);
-					if (measure_item(pcr, digest, sizeof(digest),
-							 (int8_t *)name, 0))
-						printk(BIOS_DEBUG, "%s: measuring failed!\n",
-						       __func__);
+					rc = measure_item(pcr, digest, sizeof(digest),
+							 (int8_t *)name, 0);
+					if (rc)
+						printk(BIOS_DEBUG, "%s: measuring failed with error %#x!\n",
+						       __func__, rc);
 				}
 			}
 			if (CONFIG(VENDORCODE_ELTAN_VBOOT))
diff --git a/src/vendorcode/google/chromeos/cr50_enable_update.c b/src/vendorcode/google/chromeos/cr50_enable_update.c
index abc132dd6e..3202564303 100644
--- a/src/vendorcode/google/chromeos/cr50_enable_update.c
+++ b/src/vendorcode/google/chromeos/cr50_enable_update.c
@@ -25,7 +25,7 @@ void __weak mainboard_prepare_cr50_reset(void) {}
  */
 static int cr50_is_reset_needed(void)
 {
-	int rc;
+	tpm_result_t rc;
 	uint8_t tpm_mode;
 
 	rc = tlcl_cr50_get_tpm_mode(&tpm_mode);
@@ -70,7 +70,7 @@ static int cr50_is_reset_needed(void)
 
 static void enable_update(void *unused)
 {
-	int rc;
+	tpm_result_t rc;
 	int cr50_reset_reqd = 0;
 	uint8_t num_restored_headers;
 
@@ -84,7 +84,7 @@ static void enable_update(void *unused)
 
 	rc = tlcl_lib_init();
 
-	if (rc != VB2_SUCCESS) {
+	if (rc != TPM_SUCCESS) {
 		printk(BIOS_ERR, "tlcl_lib_init() failed for CR50 update: %#x\n",
 		       rc);
 		return;
diff --git a/src/vendorcode/google/chromeos/cse_board_reset.c b/src/vendorcode/google/chromeos/cse_board_reset.c
index 87c49164c0..e7cb878b68 100644
--- a/src/vendorcode/google/chromeos/cse_board_reset.c
+++ b/src/vendorcode/google/chromeos/cse_board_reset.c
@@ -13,7 +13,7 @@
 
 void cse_board_reset(void)
 {
-	int rc;
+	tpm_result_t rc;
 	struct cr50_firmware_version version;
 
 	if (CONFIG(CSE_RESET_CLEAR_EC_AP_IDLE_FLAG))
@@ -22,7 +22,7 @@ void cse_board_reset(void)
 	if (CONFIG(TPM2) && CONFIG(TPM_GOOGLE_CR50)) {
 		/* Initialize TPM and get the cr50 firmware version. */
 		rc = tlcl_lib_init();
-		if (rc != VB2_SUCCESS) {
+		if (rc != TPM_SUCCESS) {
 			printk(BIOS_ERR, "tlcl_lib_init() failed: %#x\n", rc);
 			return;
 		}
diff --git a/src/vendorcode/google/chromeos/tpm2.c b/src/vendorcode/google/chromeos/tpm2.c
index 8e3a4ebb51..9a99f7d285 100644
--- a/src/vendorcode/google/chromeos/tpm2.c
+++ b/src/vendorcode/google/chromeos/tpm2.c
@@ -7,7 +7,7 @@
 
 static void disable_platform_hierarchy(void *unused)
 {
-	int rc;
+	tpm_result_t rc;
 
 	if (!CONFIG(TPM2))
 		return;
@@ -17,7 +17,7 @@ static void disable_platform_hierarchy(void *unused)
 
 	rc = tlcl_lib_init();
 
-	if (rc != VB2_SUCCESS) {
+	if (rc != TPM_SUCCESS) {
 		printk(BIOS_ERR, "tlcl_lib_init() failed: %#x\n", rc);
 		return;
 	}