tpm: Add support for new Infineon I2C TPM (SLB 9645 TT 1.2 I2C)

This driver adds support for Infineon's new SLB 9645 TT 1.2 I2C TPMs,
which supports clockstretching, combined reads and a bus speed of
up to 400khz. The device also has a new device id.

The driver works now also fine with device trees, so you can
instantiate your device by adding:
 +       tpm {
 +               compatible = "infineon,slb9645tt";
 +               reg = <0x20>;
 +       };
 for SLB 9645 devices or

 +       tpm {
 +               compatible = "infineon,slb9635tt";
 +               reg = <0x20>;
 +       };
 for SLB 9635 devices

to your device tree.
tpm_i2c_infineon is also retained as a compatible id as a fallback to
slb9635 protocol.

The driver was tested on Beaglebone.

Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 446859fcdca4..ad6a73852f08 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -35,6 +35,8 @@ fsl,mc13892		MC13892: Power Management Integrated Circuit (PMIC) for i.MX35/51
 fsl,mma8450             MMA8450Q: Xtrinsic Low-power, 3-axis Xtrinsic Accelerometer
 fsl,mpr121              MPR121: Proximity Capacitive Touch Sensor Controller
 fsl,sgtl5000            SGTL5000: Ultra Low-Power Audio Codec
+infineon,slb9635tt      Infineon SLB9635 (Soft-) I2C TPM (old protocol, max 100khz)
+infineon,slb9645tt      Infineon SLB9645 I2C TPM (new protocol, max 400khz)
 maxim,ds1050            5 Bit Programmable, Pulse-Width Modulator
 maxim,max1237           Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
 maxim,max6625           9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface