[coreboot-gerrit] [S] Change in coreboot[master]: drivers/spi/tpm: verify device supports TPM2

[Sergii Dmytruk (Code Review)]

Attention is currently required from: Michał Żygowski, Julius Werner, Krystian Hebel.

Hello Michał Żygowski, Julius Werner, Krystian Hebel,

I'd like you to do a code review.
Please visit

https://review.coreboot.org/c/coreboot/+/69022

to review the following change.

Change subject: drivers/spi/tpm: verify device supports TPM2
......................................................................

drivers/spi/tpm: verify device supports TPM2

This is to handle the situation when device ID is the same for TPM1 and
TPM2 versions of a device.

Change-Id: Ib2840a21b3be8928d39570281f86a0e26b38b5f9
Ticket: https://ticket.coreboot.org/issues/433
Signed-off-by: Sergii Dmytruk 
---
M src/drivers/spi/tpm/tpm.c
1 file changed, 25 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/22/69022/1

diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c
index 68f9588..8b390f0 100644
--- a/src/drivers/spi/tpm/tpm.c
+++ b/src/drivers/spi/tpm/tpm.c
@@ -28,6 +28,7 @@
 #define TPM_ACCESS_REG    (TPM_LOCALITY_0_SPI_BASE + 0)
 #define TPM_STS_REG       (TPM_LOCALITY_0_SPI_BASE + 0x18)
 #define TPM_DATA_FIFO_REG (TPM_LOCALITY_0_SPI_BASE + 0x24)
+#define TPM_INTF_ID_REG   (TPM_LOCALITY_0_SPI_BASE + 0x30)
 #define TPM_DID_VID_REG   (TPM_LOCALITY_0_SPI_BASE + 0xf00)
 #define TPM_RID_REG       (TPM_LOCALITY_0_SPI_BASE + 0xf04)
 #define TPM_FW_VER	  (TPM_LOCALITY_0_SPI_BASE + 0xf90)
@@ -412,7 +413,7 @@

int tpm2_init(struct spi_slave *spi_if)
 {
-	uint32_t did_vid, status;
+	uint32_t did_vid, status, intf_id;
    uint8_t cmd;
    int retries;

@@ -454,6 +455,15 @@

printk(BIOS_INFO, " done!\n");

+	if (tpm2_read_reg(TPM_INTF_ID_REG, &intf_id, sizeof(intf_id)) != CB_SUCCESS) {
+		printk(BIOS_ERR, "\n%s: Failed to read interface ID register\n", __func__);
+		return -1;
+	}
+	if ((be32toh(intf_id) & 0xF) == 0xF) {
+		printk(BIOS_DEBUG, "\n%s: Not a TPM2 device\n", __func__);
+		return -1;
+	}
+
    // FIXME: Move this to tpm_setup()
    if (tpm_first_access_this_boot())
    	/*