drivers/i2c/tpm: Fix early TPM probe

The early TPM probe was done directly in tis.c ignoring the lower
layer that provides appropriate access to the chip.  Move this into
a tpm_vendor_probe() function so it can use iic_tpm_read() with all
of the built-in delays and semantics instead of calling i2c_readb()
directly from the wrong layer.

This fixes early init failures that were seen with the cr50 i2c tpm
on the reef mainboard.

Change-Id: I9bb3b820d10f6e2ea24c57b90cf0edc813cdc7e0
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/16527
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/drivers/i2c/tpm/tpm.h b/src/drivers/i2c/tpm/tpm.h
index 7dfd59481d..ddf12a9e98 100644
--- a/src/drivers/i2c/tpm/tpm.h
+++ b/src/drivers/i2c/tpm/tpm.h
@@ -121,6 +121,8 @@ struct tpm_cmd_t {
 
 /* ---------- Interface for TPM vendor ------------ */
 
+int tpm_vendor_probe(unsigned bus, uint32_t addr);
+
 int tpm_vendor_init(struct tpm_chip *chip, unsigned bus, uint32_t dev_addr);
 
 void tpm_vendor_cleanup(struct tpm_chip *chip);