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

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

Change-Id: Ib4ce35ada24e3959ea1a518c29d431b4ae123809
Ticket: https://ticket.coreboot.org/issues/433
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68991
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 21 insertions, 21 deletions

diff --git a/src/drivers/pc80/tpm/tis.c b/src/drivers/pc80/tpm/tis.c
index ce88ae012d..42ad19298c 100644
--- a/src/drivers/pc80/tpm/tis.c
+++ b/src/drivers/pc80/tpm/tis.c
@@ -373,7 +373,7 @@ static int tis_command_ready(u8 locality)
  * 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.
  */
-static u32 tis_probe(void)
+static u32 pc80_tis_probe(void)
 {
 	const char *device_name = "unknown";
 	const char *vendor_name = device_name;
@@ -608,26 +608,11 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 }
 
 /*
- * tis_init()
- *
- * Initialize the TPM device. Returns 0 on success or TPM_DRIVER_ERR on
- * failure (in case device probing did not succeed).
- */
-int tis_init(void)
-{
-	if (tis_probe())
-		return TPM_DRIVER_ERR;
-	return 0;
-}
-
-/*
- * tis_open()
- *
  * Requests access to locality 0 for the caller.
  *
  * Returns 0 on success, TPM_DRIVER_ERR on failure.
  */
-int tis_open(void)
+static int pc80_tis_open(void)
 {
 	u8 locality = 0; /* we use locality zero for everything */
 
@@ -653,8 +638,6 @@ int tis_open(void)
 }
 
 /*
- * tis_sendrecv()
- *
  * Send the requested data to the TPM and then try to get its response
  *
  * @sendbuf - buffer of the data to send
@@ -665,8 +648,8 @@ int tis_open(void)
  * Returns 0 on success (and places the number of response bytes at recv_len)
  * or TPM_DRIVER_ERR on failure.
  */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
-		 uint8_t *recvbuf, size_t *recv_len)
+static int pc80_tpm_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",
@@ -678,6 +661,23 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
 }
 
 /*
+ * tis_probe()
+ *
+ * Probe for the TPM device and set it up for use within locality 0. Returns
+ * pointer to send-receive function on success or NULL on failure.
+ */
+tis_sendrecv_fn tis_probe(void)
+{
+	if (pc80_tis_probe())
+		return NULL;
+
+	if (pc80_tis_open())
+		return NULL;
+
+	return &pc80_tpm_sendrecv;
+}
+
+/*
  * tis_setup_interrupt()
  *
  * Set up the interrupt vector and polarity for locality 0 and