tpm: Allow separate handling of Google Ti50 TPM
A new iteration of Google's TPM implementation will advertize a new
DID:VID, but otherwise follow the same protocol as the earlier design.
This change makes use of Kconfigs TPM_GOOGLE_CR50 and TPM_GOOGLE_TI50
to be able to take slightly different code paths, when e.g. evaluating
whether TPM firmware is new enough to support certain features.
Change-Id: I1e1f8eb9b94fc2d5689656335dc1135b47880986
Signed-off-by: Jes B. Klinke <jbk@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63158
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
diff --git a/src/drivers/i2c/tpm/Kconfig b/src/drivers/i2c/tpm/Kconfig
index 8efcbaf..0e7856d 100644
--- a/src/drivers/i2c/tpm/Kconfig
+++ b/src/drivers/i2c/tpm/Kconfig
@@ -3,15 +3,6 @@
help
I2C TPM driver is enabled!
-config MAINBOARD_NEEDS_I2C_TI50_WORKAROUND
- bool
- default n
- help
- Ti50 FW versions below 0.15 don't support the firmware_version or board_cfg registers,
- and trying to access them causes I2C errors. This config will skip accesses to these
- registers, and should be selected for boards using Ti50 chips with FW < 0.15. The config
- will be removed once all Ti50 stocks are updated to 0.15 or higher.
-
config DRIVER_TIS_DEFAULT
bool
depends on I2C_TPM
diff --git a/src/drivers/i2c/tpm/cr50.c b/src/drivers/i2c/tpm/cr50.c
index 7eb066d..0130b93 100644
--- a/src/drivers/i2c/tpm/cr50.c
+++ b/src/drivers/i2c/tpm/cr50.c
@@ -36,6 +36,7 @@
#define CR50_TIMEOUT_NOIRQ_MS 20 /* Timeout for TPM ready without IRQ */
#define CR50_TIMEOUT_IRQ_MS 100 /* Timeout for TPM ready with IRQ */
#define CR50_DID_VID 0x00281ae0L
+#define TI50_DID_VID 0x504a6666L
struct tpm_inf_dev {
int bus;
@@ -455,7 +456,7 @@
rc = cr50_i2c_read(TPM_DID_VID(0), (uint8_t *)did_vid, 4);
/* Exit once DID and VID verified */
- if (!rc && (*did_vid == CR50_DID_VID)) {
+ if (!rc && (*did_vid == CR50_DID_VID || *did_vid == TI50_DID_VID)) {
printk(BIOS_INFO, "done! DID_VID 0x%08x\n", *did_vid);
return 0;
}
@@ -474,7 +475,6 @@
int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
{
- struct cr50_firmware_version ver;
uint32_t did_vid = 0;
if (dev_addr == 0) {
@@ -500,12 +500,10 @@
printk(BIOS_DEBUG, "cr50 TPM 2.0 (i2c %u:0x%02x id 0x%x)\n",
bus, dev_addr, did_vid >> 16);
- /* Ti50 FW version under 0.15 doesn't support board cfg command
- TODO: remove this flag after all stocks Ti50 uprev to 0.15 or above */
- if (!CONFIG(MAINBOARD_NEEDS_I2C_TI50_WORKAROUND) && tpm_first_access_this_boot()) {
+ if (tpm_first_access_this_boot()) {
/* This is called for the side-effect of printing the version string. */
- cr50_get_firmware_version(&ver);
- cr50_set_board_cfg();
+ cr50_get_firmware_version(NULL);
+ cr50_set_board_cfg();
}
chip->is_open = 1;
diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c
index 1462dd9..8625a79 100644
--- a/src/drivers/spi/tpm/tpm.c
+++ b/src/drivers/spi/tpm/tpm.c
@@ -419,6 +419,7 @@
/* Device/vendor ID values of the TPM devices this driver supports. */
static const uint32_t supported_did_vids[] = {
0x00281ae0, /* H1 based Cr50 security chip. */
+ 0x504a6666, /* H1D3C based Ti50 security chip. */
0x0000104a /* ST33HTPH2E32 */
};
@@ -496,15 +497,13 @@
printk(BIOS_INFO, "Connected to device vid:did:rid of %4.4x:%4.4x:%2.2x\n",
tpm_info.vendor_id, tpm_info.device_id, tpm_info.revision);
- /* Do some cr50-specific things here. */
- if (CONFIG(TPM_GOOGLE) && tpm_info.vendor_id == 0x1ae0) {
- struct cr50_firmware_version ver;
-
+ /* Do some GSC-specific things here. */
+ if (CONFIG(TPM_GOOGLE)) {
if (tpm_first_access_this_boot()) {
/* This is called for the side-effect of printing the firmware version
string */
- cr50_get_firmware_version(&ver);
- cr50_set_board_cfg();
+ cr50_get_firmware_version(NULL);
+ cr50_set_board_cfg();
}
}
return 0;
diff --git a/src/drivers/tpm/cr50.c b/src/drivers/tpm/cr50.c
index 4ab01fb..22ca3dd 100644
--- a/src/drivers/tpm/cr50.c
+++ b/src/drivers/tpm/cr50.c
@@ -5,6 +5,9 @@
#include <string.h>
#include <types.h>
+#define CR50_DID_VID 0x00281ae0L
+#define TI50_DID_VID 0x504a6666L
+
#define CR50_BOARD_CFG_LOCKBIT_MASK 0x80000000U
#define CR50_BOARD_CFG_FEATUREBITS_MASK 0x3FFFFFFFU
@@ -84,7 +87,7 @@
const enum cb_err ret = tis_vendor_read(get_reg_addr(CR50_BOARD_CFG_REG), &value,
sizeof(value));
if (ret != CB_SUCCESS) {
- printk(BIOS_INFO, "Error reading from cr50\n");
+ printk(BIOS_ERR, "Error reading from Cr50\n");
return 0;
}
@@ -96,6 +99,11 @@
*/
enum cb_err cr50_set_board_cfg(void)
{
+ /* If we get here and we aren't cr50, then we must be ti50 which does
+ * not currently need to support a board_cfg register. */
+ if (!CONFIG(TPM_GOOGLE_CR50))
+ return CB_SUCCESS;
+
struct cr50_firmware_version ver;
enum cb_err ret;
uint32_t value;
@@ -109,7 +117,7 @@
/* Set the CR50_BOARD_CFG register, for e.g. asking cr50 to use longer ready pulses. */
ret = tis_vendor_read(get_reg_addr(CR50_BOARD_CFG_REG), &value, sizeof(value));
if (ret != CB_SUCCESS) {
- printk(BIOS_INFO, "Error reading from cr50\n");
+ printk(BIOS_ERR, "Error reading from Cr50\n");
return CB_ERR;
}
@@ -142,19 +150,15 @@
bool cr50_is_long_interrupt_pulse_enabled(void)
{
- /*
- * Ti50 FW versions under 0.15 don't support the board cfg register,
- * and all Ti50 versions only support long IRQ pulses.
- * TODO: Remove this after all Ti50 stocks uprev to 0.15 or above.
- */
- if (CONFIG(MAINBOARD_NEEDS_I2C_TI50_WORKAROUND))
- return true;
+ if (CONFIG(TPM_GOOGLE_CR50))
+ return !!(cr50_get_board_cfg() & CR50_BOARD_CFG_100US_READY_PULSE);
- return !!(cr50_get_board_cfg() & CR50_BOARD_CFG_100US_READY_PULSE);
+ /* Ti50 and future GSCs will support only long interrupt pulses. */
+ return true;
}
static enum cb_err cr50_parse_fw_version(const char *version_str,
- struct cr50_firmware_version *ver)
+ struct cr50_firmware_version *ver)
{
int epoch, major, minor;
@@ -219,6 +223,7 @@
}
success:
- *version = cr50_firmware_version;
+ if (version)
+ *version = cr50_firmware_version;
return CB_SUCCESS;
}
diff --git a/src/drivers/tpm/cr50.h b/src/drivers/tpm/cr50.h
index f754e13..b39d744 100644
--- a/src/drivers/tpm/cr50.h
+++ b/src/drivers/tpm/cr50.h
@@ -5,7 +5,7 @@
#include <types.h>
-/* Structure describing the elements of Cr50 firmware version. */
+/* Structure describing the elements of GSC firmware version. */
struct cr50_firmware_version {
int epoch;
int major;
@@ -15,7 +15,7 @@
/* Indicates whether Cr50 ready pulses are guaranteed to be at least 100us. */
bool cr50_is_long_interrupt_pulse_enabled(void);
-/* Get the Cr50 firmware version information. */
+/* Get the GSC firmware version information. */
enum cb_err cr50_get_firmware_version(struct cr50_firmware_version *version);
/* Set the BOARD_CFG register depending on Cr50 Kconfigs */