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>

1 files changed, 13 insertions, 19 deletions

diff --git a/src/security/tpm/tis.h b/src/security/tpm/tis.h
index 34dc8e8bd786..ac07bfb5c619 100644
--- a/src/security/tpm/tis.h
+++ b/src/security/tpm/tis.h
@@ -33,23 +33,6 @@ enum tis_status {
 };
 
 /*
- * tis_init()
- *
- * Initialize the TPM device.
- * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
- */
-tpm_result_t tis_init(void);
-
-/*
- * tis_open()
- *
- * Requests access to locality 0 for the caller.
- *
- * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
- */
-tpm_result_t tis_open(void);
-
-/*
  * tis_sendrecv()
  *
  * Send the requested data to the TPM and then try to get its response
@@ -61,8 +44,19 @@ tpm_result_t tis_open(void);
  *
  * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-tpm_result_t tis_sendrecv(const u8 *sendbuf, size_t send_size, u8 *recvbuf,
-			size_t *recv_len);
+typedef tpm_result_t (*tis_sendrecv_fn)(const u8 *sendbuf, size_t send_size, u8 *recvbuf,
+					size_t *recv_len);
+
+/*
+ * 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.
+ *
+ * Do not call this explicitly, it's meant to be used exclusively by TSS
+ * implementation (tlcl_lib_init() function to be specific).
+ */
+tis_sendrecv_fn tis_probe(void);
 
 /*
  * tis_vendor_write()