[PATCH v6] tpm: Add new device/vendor ID 0x50666666

[Jett Rink]

Accept another DID:VID for the next generation Google TPM. This TPM
has the same Ti50 firmware and fulfills the same interface.

Suggested-by: Jarkko Sakkinen <jarkko at kernel.org>
Signed-off-by: Jett Rink <jettrink at chromium.org>
---

Changes in v6:
Update comments and string based on internal review.

Changes in v5:
Correct Suggested-by tag form.

Changes in v4:
Add Suggested-by tag. Sorry that I forget.

Changes in v3:
Refactor ternary operators into helper method.

Changes in v2:
Patchset 2 applies cleanly

 drivers/char/tpm/tpm_tis_i2c_cr50.c | 32 +++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
index adf22992138e..fea744234aa0 100644
--- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
+++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
@@ -30,8 +30,9 @@
 #define TPM_CR50_MAX_BUFSIZE		64
 #define TPM_CR50_TIMEOUT_SHORT_MS	2		/* Short timeout during transactions */
 #define TPM_CR50_TIMEOUT_NOIRQ_MS	20		/* Timeout for TPM ready without IRQ */
-#define TPM_CR50_I2C_DID_VID		0x00281ae0L	/* Device and vendor ID reg value */
-#define TPM_TI50_I2C_DID_VID		0x504a6666L	/* Device and vendor ID reg value */
+#define TPM_CR50_I2C_DID_VID		0x00281ae0L	/* Device and vendor ID for Cr50 H1 */
+#define TPM_TI50_DT_I2C_DID_VID		0x504a6666L	/* Device and vendor ID for Ti50 DT */
+#define TPM_TI50_OT_I2C_DID_VID		0x50666666L	/* Device and vendor ID for TI50 OT */
 #define TPM_CR50_I2C_MAX_RETRIES	3		/* Max retries due to I2C errors */
 #define TPM_CR50_I2C_RETRY_DELAY_LO	55		/* Min usecs between retries on I2C */
 #define TPM_CR50_I2C_RETRY_DELAY_HI	65		/* Max usecs between retries on I2C */
@@ -668,6 +669,27 @@ static const struct of_device_id of_cr50_i2c_match[] = {
 MODULE_DEVICE_TABLE(of, of_cr50_i2c_match);
 #endif
 
+/**
+ * tpm_cr50_vid_to_name() - Maps VID to name.
+ * @vendor:	Vendor identifier to map to name
+ *
+ * Return:
+ *	A valid string for the vendor or empty string
+ */
+static const char *tpm_cr50_vid_to_name(u32 vendor)
+{
+	switch (vendor) {
+	case TPM_CR50_I2C_DID_VID:
+		return "cr50";
+	case TPM_TI50_DT_I2C_DID_VID:
+		return "ti50 DT";
+	case TPM_TI50_OT_I2C_DID_VID:
+		return "ti50 OT";
+	default:
+		return "unknown";
+	}
+}
+
 /**
  * tpm_cr50_i2c_probe() - Driver probe function.
  * @client:	I2C client information.
@@ -741,14 +763,16 @@ static int tpm_cr50_i2c_probe(struct i2c_client *client)
 	}
 
 	vendor = le32_to_cpup((__le32 *)buf);
-	if (vendor != TPM_CR50_I2C_DID_VID && vendor != TPM_TI50_I2C_DID_VID) {
+	if (vendor != TPM_CR50_I2C_DID_VID &&
+	    vendor != TPM_TI50_DT_I2C_DID_VID &&
+	    vendor != TPM_TI50_OT_I2C_DID_VID) {
 		dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor);
 		tpm_cr50_release_locality(chip, true);
 		return -ENODEV;
 	}
 
 	dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n",
-		 vendor == TPM_TI50_I2C_DID_VID ? "ti50" : "cr50",
+		 tpm_cr50_vid_to_name(vendor),
 		 client->addr, client->irq, vendor >> 16);
 	return tpm_chip_register(chip);
 }
-- 
2.46.0.662.g92d0881bb0-goog