commit 493077b68cf46b08f0d1ddfe57bf6064d714d537
author Daisuke Nojiri <dnojiri@chromium.org> Wed Oct 29 11:14:53 2014 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> Wed Oct 29 22:24:07 2014 +0000
tree 80c12696ccdd183855ed1ac9eca648107be27db4
parent bd0921b283c7ef23c0528618239619e394c5176a

tpm: allow 0 as valid i2c bus number

tpm driver uses bus=0 as indication of uninitialized tpm device. this
change allows 0 as a valid i2c bus number.

BUG=None
BRANCH=ToT
TEST=Built cosmos.

Change-Id: Iac55e88db4ef757a292270e7201d8fdd37a90b50
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/226294
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/drivers/i2c/tpm/tpm.c

diff --git a/src/drivers/i2c/tpm/tpm.c b/src/drivers/i2c/tpm/tpm.c
index bc36e35..dc4ab78 100644
--- a/src/drivers/i2c/tpm/tpm.c
+++ b/src/drivers/i2c/tpm/tpm.c
@@ -86,13 +86,14 @@
 
 /* Structure to store I2C TPM specific stuff */
 struct tpm_inf_dev {
-	unsigned bus;
+	int bus;
 	unsigned int addr;
 	uint8_t buf[TPM_BUFSIZE + sizeof(uint8_t)]; // max. buffer size + addr
 	enum i2c_chip_type chip_type;
 };
 
 static struct tpm_inf_dev tpm_dev = {
+	.bus = -1,
 	.addr = TPM_I2C_ADDR
 };
 
@@ -115,7 +116,7 @@
 	int rc;
 	int count;
 
-	if (!tpm_dev.bus)
+	if (tpm_dev.bus < 0)
 		return -1;
 	if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
 		/* slb9635 protocol should work in both cases */
@@ -186,7 +187,7 @@
 	tpm_dev.buf[0] = addr;
 	memcpy(&(tpm_dev.buf[1]), buffer, len);
 
-	if (!tpm_dev.bus)
+	if (tpm_dev.bus < 0)
 		return -1;
 	for (count = 0; count < max_count; count++) {
 		rc = i2c_write_raw(tpm_dev.bus, tpm_dev.addr,