tpm: Add support for the Nuvoton NPCT501 I2C TPM

This chip is/was also branded as a Winbond WPCT301.

Originally written by Dan Morav <dmorav@nuvoton.com> and posted to LKML:
https://lkml.org/lkml/2011/9/7/206

The original posting was not merged, I have taken it as a
starting point, forward ported, tested and revised the driver:
 - Rework interrupt handling to work properly with level triggered
   interrupts. The old version just locked up.
 - Synchronize various items with Peter Huewe's Infineon driver:
    * Add durations/timeouts sysfs calls
    * Remove I2C device auto-detection
    * Don't fiddle with chip->release
    * Call tpm_dev_vendor_release in the probe error path
    * Use MODULE_DEVICE_TABLE for the I2C ids
    * Provide OF compatible strings for DT support
    * Use SIMPLE_DEV_PM_OPS
    * Use module_i2c_driver
 - checkpatch cleanups
 - Testing on ARM Kirkwood with GPIO interrupts, with this device tree:
	tpm@57 {
                compatible = "nuvoton,npct501";
                reg = <0x57>;
                interrupt-parent = <&gpio1>;
                interrupts = <6 IRQ_TYPE_LEVEL_LOW>;
        };
Signed-off-by: Dan Morav <dmorav@nuvoton.com>
[jgg: revised and tested]
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
[phuewe: minor whitespace changes, fixed module name in kconfig]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

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

@@ -44,6 +44,7 @@ mc,rv3029c2		Real Time Clock Module with I2C-Bus
 national,lm75		I2C TEMP SENSOR
 national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
 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)
 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
@@ -61,3 +62,4 @@ taos,tsl2550		Ambient Light Sensor with SMBUS/Two Wire Serial Interface
 ti,tsc2003		I2C Touch-Screen Controller
 ti,tmp102		Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface
 ti,tmp275		Digital Temperature Sensor
+winbond,wpct301		i2c trusted platform module (TPM)

drivers/char/tpm/Kconfig

@@ -44,6 +44,16 @@ config TCG_TIS_I2C_INFINEON
 	  To compile this driver as a module, choose M here; the module
 	  will be called tpm_tis_i2c_infineon.
 
+config TCG_TIS_I2C_NUVOTON
+	tristate "TPM Interface Specification 1.2 Interface (I2C - Nuvoton)"
+	depends on I2C
+	---help---
+	  If you have a TPM security chip with an I2C interface from
+	  Nuvoton Technology Corp. say Yes and it will be accessible
+	  from within Linux.
+	  To compile this driver as a module, choose M here; the module
+	  will be called tpm_i2c_nuvoton.
+
 config TCG_NSC
 	tristate "National Semiconductor TPM Interface"
 	depends on X86

drivers/char/tpm/Makefile

@@ -14,6 +14,7 @@ endif
 endif
 obj-$(CONFIG_TCG_TIS) += tpm_tis.o
 obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
+obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o
 obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
 obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
 obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o