security/tpm/: turn tis_{init,open} into tis_probe

init() was always followed by open() and after successful initialization
we only need send-receive function which is now returned by tis_probe()
on success, thus further reducing number of functions to export from
drivers.

This also removes check for opening TIS twice that seems to have no
value.

Change-Id: I52ad8d69d50d449f031c36b15bf70ef07986946c
Ticket: https://ticket.coreboot.org/issues/433
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76954
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

5 files changed, 20 insertions, 41 deletions

diff --git a/src/drivers/i2c/tpm/cr50.c b/src/drivers/i2c/tpm/cr50.c
index 3351ca2700..8462198410 100644
--- a/src/drivers/i2c/tpm/cr50.c
+++ b/src/drivers/i2c/tpm/cr50.c
@@ -505,7 +505,6 @@ tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t d
                 cr50_set_board_cfg();
 	}
 
-	chip->is_open = 1;
 	return TPM_SUCCESS;
 }
 
diff --git a/src/drivers/i2c/tpm/tis.c b/src/drivers/i2c/tpm/tis.c
index a5c3b8fdf3..6cb05f0dd7 100644
--- a/src/drivers/i2c/tpm/tis.c
+++ b/src/drivers/i2c/tpm/tis.c
@@ -19,29 +19,6 @@ static struct tpm_chip chip;
 #define TPM_CMD_COUNT_BYTE 2
 #define TPM_CMD_ORDINAL_BYTE 6
 
-tpm_result_t tis_open(void)
-{
-	tpm_result_t rc;
-
-	if (chip.is_open) {
-		printk(BIOS_DEBUG, "%s() called twice.\n", __func__);
-		return TPM_CB_FAIL;
-	}
-
-	rc = tpm_vendor_init(&chip, CONFIG_DRIVER_TPM_I2C_BUS,
-			     CONFIG_DRIVER_TPM_I2C_ADDR);
-	if (rc != TPM_SUCCESS)
-		chip.is_open = 0;
-
-	return rc;
-}
-
-tpm_result_t tis_init(void)
-{
-	return tpm_vendor_probe(CONFIG_DRIVER_TPM_I2C_BUS,
-				CONFIG_DRIVER_TPM_I2C_ADDR);
-}
-
 static ssize_t tpm_transmit(const uint8_t *sbuf, size_t sbufsiz, void *rbuf,
 			size_t rbufsiz)
 {
@@ -103,8 +80,8 @@ out:
 	return rc;
 }
 
-tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
-		uint8_t *recvbuf, size_t *rbuf_len)
+static tpm_result_t i2c_tpm_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+				     uint8_t *recvbuf, size_t *rbuf_len)
 {
 	ASSERT(sbuf_size >= 10);
 
@@ -140,3 +117,14 @@ tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 
 	return TPM_SUCCESS;
 }
+
+tis_sendrecv_fn tis_probe(void)
+{
+	if (tpm_vendor_probe(CONFIG_DRIVER_TPM_I2C_BUS, CONFIG_DRIVER_TPM_I2C_ADDR))
+		return NULL;
+
+	if (tpm_vendor_init(&chip, CONFIG_DRIVER_TPM_I2C_BUS, CONFIG_DRIVER_TPM_I2C_ADDR))
+		return NULL;
+
+	return &i2c_tpm_sendrecv;
+}
diff --git a/src/drivers/i2c/tpm/tis_atmel.c b/src/drivers/i2c/tpm/tis_atmel.c
index 91ed6a99e3..0a29049d95 100644
--- a/src/drivers/i2c/tpm/tis_atmel.c
+++ b/src/drivers/i2c/tpm/tis_atmel.c
@@ -22,18 +22,8 @@ struct tpm_output_header {
 	uint32_t return_code;
 } __packed;
 
-tpm_result_t tis_open(void)
-{
-	return TPM_SUCCESS;
-}
-
-tpm_result_t tis_init(void)
-{
-	return TPM_SUCCESS;
-}
-
-tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
-		uint8_t *recvbuf, size_t *rbuf_len)
+static tpm_result_t i2c_tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+				     uint8_t *recvbuf, size_t *rbuf_len)
 {
 	size_t hdr_bytes;
 	struct tpm_output_header *header;
@@ -116,3 +106,8 @@ tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 	/* Successful transfer */
 	return TPM_SUCCESS;
 }
+
+tis_sendrecv_fn tis_probe(void)
+{
+	return &i2c_tis_sendrecv;
+}
diff --git a/src/drivers/i2c/tpm/tpm.c b/src/drivers/i2c/tpm/tpm.c
index 91c310b8f3..541eb3aaa0 100644
--- a/src/drivers/i2c/tpm/tpm.c
+++ b/src/drivers/i2c/tpm/tpm.c
@@ -507,8 +507,6 @@ tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t d
 	tpm_dev.sleep_short = SLEEP_DURATION;
 	tpm_dev.sleep_long = SLEEP_DURATION_LONG;
 
-	chip->is_open = 1;
-
 	chip->req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
 	chip->req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
 	chip->req_canceled = TPM_STS_COMMAND_READY;
diff --git a/src/drivers/i2c/tpm/tpm.h b/src/drivers/i2c/tpm/tpm.h
index fb9837789d..628ad4dc69 100644
--- a/src/drivers/i2c/tpm/tpm.h
+++ b/src/drivers/i2c/tpm/tpm.h
@@ -39,7 +39,6 @@ enum tpm_timeout {
 #define	TPM_DID_VID(l)			(0x0006 | ((l) << 4))
 
 struct tpm_chip {
-	int is_open;
 	uint8_t req_complete_mask;
 	uint8_t req_complete_val;
 	uint8_t req_canceled;