tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)

The command flow is exactly the same, the core simply needs to be
told to enable TPM2 mode when the compatible string indicates a
TPM2.

Signed-off-by: Andrew Azmansky <andrew.zamansky@nuvoton.com>
Tested-by: Andrew Zamansky <andrew.zamansky@nuvoton.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Documentation/devicetree/bindings/i2c/trivial-devices.txt

@@ -62,6 +62,7 @@ national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware M
 national,lm85		Temperature sensor with integrated fan control
 national,lm92		±0.33°C Accurate, 12-Bit + Sign Temperature Sensor and Thermal Window Comparator with Two-Wire Interface
 nuvoton,npct501		i2c trusted platform module (TPM)
+nuvoton,npct601		i2c trusted platform module (TPM2)
 nxp,pca9556		Octal SMBus and I2C registered interface
 nxp,pca9557		8-bit I2C-bus and SMBus I/O port with reset
 nxp,pcf8563		Real-time clock/calendar

drivers/char/tpm/tpm_i2c_nuvoton.c

@@ -1,5 +1,5 @@
-/******************************************************************************
- * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501,
+ /******************************************************************************
+ * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501/NPCT6XX,
  * based on the TCG TPM Interface Spec version 1.2.
  * Specifications at www.trustedcomputinggroup.org
  *
@@ -31,6 +31,7 @@
 #include <linux/interrupt.h>
 #include <linux/wait.h>
 #include <linux/i2c.h>
+#include <linux/of_device.h>
 #include "tpm.h"
 
 /* I2C interface offsets */
@@ -52,7 +53,8 @@
 #define TPM_I2C_RETRY_DELAY_SHORT      2       /* msec */
 #define TPM_I2C_RETRY_DELAY_LONG       10      /* msec */
 
-#define I2C_DRIVER_NAME "tpm_i2c_nuvoton"
+#define OF_IS_TPM2 ((void *)1)
+#define I2C_IS_TPM2 1
 
 struct priv_data {
 	int irq;
@@ -165,7 +167,7 @@ static int i2c_nuvoton_get_burstcount(struct i2c_client *client,
 }
 
 /*
- * WPCT301/NPCT501 SINT# supports only dataAvail
+ * WPCT301/NPCT501/NPCT6XX SINT# supports only dataAvail
  * any call to this function which is not waiting for dataAvail will
  * set queue to NULL to avoid waiting for interrupt
  */
@@ -545,6 +547,16 @@ static int i2c_nuvoton_probe(struct i2c_client *client,
 	if (!priv)
 		return -ENOMEM;
 
+	if (dev->of_node) {
+		const struct of_device_id *of_id;
+
+		of_id = of_match_device(dev->driver->of_match_table, dev);
+		if (of_id && of_id->data == OF_IS_TPM2)
+			chip->flags |= TPM_CHIP_FLAG_TPM2;
+	} else
+		if (id->driver_data == I2C_IS_TPM2)
+			chip->flags |= TPM_CHIP_FLAG_TPM2;
+
 	init_waitqueue_head(&priv->read_queue);
 
 	/* Default timeouts */
@@ -620,7 +632,8 @@ static int i2c_nuvoton_remove(struct i2c_client *client)
 }
 
 static const struct i2c_device_id i2c_nuvoton_id[] = {
-	{I2C_DRIVER_NAME, 0},
+	{"tpm_i2c_nuvoton"},
+	{"tpm2_i2c_nuvoton", .driver_data = I2C_IS_TPM2},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
@@ -629,6 +642,7 @@ MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
 static const struct of_device_id i2c_nuvoton_of_match[] = {
 	{.compatible = "nuvoton,npct501"},
 	{.compatible = "winbond,wpct301"},
+	{.compatible = "nuvoton,npct601", .data = OF_IS_TPM2},
 	{},
 };
 MODULE_DEVICE_TABLE(of, i2c_nuvoton_of_match);
@@ -641,7 +655,7 @@ static struct i2c_driver i2c_nuvoton_driver = {
 	.probe = i2c_nuvoton_probe,
 	.remove = i2c_nuvoton_remove,
 	.driver = {
-		.name = I2C_DRIVER_NAME,
+		.name = "tpm_i2c_nuvoton",
 		.pm = &i2c_nuvoton_pm_ops,
 		.of_match_table = of_match_ptr(i2c_nuvoton_of_match),
 	},