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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>
This commit is contained in:
Duncan Laurie 2016-09-07 10:52:12 -07:00
parent 7fbdad80fd
commit 1ca196841a
3 changed files with 46 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
src/drivers/i2c/tpm/tis.c
View File

@ -31,7 +31,6 @@ static struct tpm_chip g_chip CAR_GLOBAL;
#define TPM_CMD_COUNT_BYTE 2
#define TPM_CMD_ORDINAL_BYTE 6
#define TPM_VALID_STATUS (1 << 7)
int tis_open(void)
{
@ -69,38 +68,8 @@ int tis_close(void)
int tis_init(void)
{
int bus = CONFIG_DRIVER_TPM_I2C_BUS;
int chip = CONFIG_DRIVER_TPM_I2C_ADDR;
struct stopwatch sw;
uint8_t buf = 0;
int ret;
long sw_run_duration = 750;
/*
* Probe TPM. Check if the TPM_ACCESS register's ValidSts bit is set(1)
* If the bit remains clear(0) then claim that init has failed.
*/
stopwatch_init_msecs_expire(&sw, sw_run_duration);
do {
ret = i2c_readb(bus, chip, 0, &buf);
if (!ret && (buf & TPM_VALID_STATUS)) {
sw_run_duration = stopwatch_duration_msecs(&sw);
break;
}
} while (!stopwatch_expired(&sw));
printk(BIOS_INFO,
"%s: ValidSts bit %s(%d) in TPM_ACCESS register after %ld ms\n",
__func__, (buf & TPM_VALID_STATUS) ? "set" : "clear",
(buf & TPM_VALID_STATUS) >> 7, sw_run_duration);
/*
* Claim failure if the ValidSts (bit 7) is clear.
*/
if (!(buf & TPM_VALID_STATUS))
return -1;
return 0;
return tpm_vendor_probe(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR);
}
static ssize_t tpm_transmit(const uint8_t *buf, size_t bufsiz)

42
src/drivers/i2c/tpm/tpm.c
View File

@ -46,6 +46,7 @@
#define SLEEP_DURATION 60 /* in usec */
#define SLEEP_DURATION_LONG 210 /* in usec */
#define SLEEP_DURATION_SAFE 750 /* in usec */
#define SLEEP_DURATION_PROBE_MS 1000 /* in msec */
/* max. number of iterations after I2C NAK for 'long' commands
* we need this especially for sending TPM_READY, since the cleanup after the
@ -695,6 +696,47 @@ out:
/* Initialization of I2C TPM */
int tpm_vendor_probe(unsigned bus, uint32_t addr)
{
struct tpm_inf_dev *tpm_dev = car_get_var_ptr(&g_tpm_dev);
struct stopwatch sw;
uint8_t buf = 0;
int ret;
long sw_run_duration = SLEEP_DURATION_PROBE_MS;
tpm_dev->chip_type = UNKNOWN;
tpm_dev->bus = bus;
tpm_dev->addr = addr;
tpm_dev->sleep_short = SLEEP_DURATION_SAFE;
tpm_dev->sleep_long = SLEEP_DURATION_SAFE * 2;
/*
* Probe TPM. Check if the TPM_ACCESS register's ValidSts bit is set(1)
* If the bit remains clear(0) then claim that init has failed.
*/
stopwatch_init_msecs_expire(&sw, sw_run_duration);
do {
ret = iic_tpm_read(TPM_ACCESS(0), &buf, 1);
if (!ret && (buf & TPM_STS_VALID)) {
sw_run_duration = stopwatch_duration_msecs(&sw);
break;
}
} while (!stopwatch_expired(&sw));
printk(BIOS_INFO,
"%s: ValidSts bit %s(%d) in TPM_ACCESS register after %ld ms\n",
__func__, (buf & TPM_STS_VALID) ? "set" : "clear",
(buf & TPM_STS_VALID) >> 7, sw_run_duration);
/*
* Claim failure if the ValidSts (bit 7) is clear.
*/
if (!(buf & TPM_STS_VALID))
return -1;
return 0;
}
int tpm_vendor_init(struct tpm_chip *chip, unsigned bus, uint32_t dev_addr)
{
struct tpm_inf_dev *tpm_dev = car_get_var_ptr(&g_tpm_dev);

2
src/drivers/i2c/tpm/tpm.h
View File

@ -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);