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.hu...@infineon.com>
---
Patch against Kent's tpmdd-02-05-13 branch

You might get an out-of-office reply, but I'm monitoring this email address 
nevertheless.
Thanks, Peter

 .../devicetree/bindings/i2c/trivial-devices.txt    |   2 +
 drivers/char/tpm/tpm_i2c_infineon.c                | 157 +++++++++++++++------
 2 files changed, 115 insertions(+), 44 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt 
b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 446859f..ad6a738 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
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c 
b/drivers/char/tpm/tpm_i2c_infineon.c
index 8fe7ac3..c4b3b9a 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Infineon Technologies
+ * Copyright (C) 2012,2013 Infineon Technologies
  *
  * Authors:
  * Peter Huewe <peter.hu...@infineon.com>
@@ -56,13 +56,21 @@
 #define TPM_TIMEOUT_US_HI  (TPM_TIMEOUT_US_LOW + 2000)
 
 /* expected value for DIDVID register */
-#define TPM_TIS_I2C_DID_VID 0x000b15d1L
+#define TPM_TIS_I2C_DID_VID_9635 0xd1150b00L
+#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
+
+enum i2c_chip_type {
+       SLB9635,
+       SLB9645,
+       UNKNOWN,
+};
 
 /* Structure to store I2C TPM specific stuff */
 struct tpm_inf_dev {
        struct i2c_client *client;
        u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */
        struct tpm_chip *chip;
+       enum i2c_chip_type chip_type;
 };
 
 static struct tpm_inf_dev tpm_dev;
@@ -89,11 +97,20 @@ static struct i2c_driver tpm_tis_i2c_driver;
  */
 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
 {
+       struct i2c_msg msg1 = {
+               .addr = tpm_dev.client->addr,
+               .len = 1,
+               .buf = &addr,
+       };
+       struct i2c_msg msg2 = {
+               .addr = tpm_dev.client->addr,
+               .flags = I2C_M_RD,
+               .len = len,
+               .buf = buffer,
+       };
+       struct i2c_msg msgs[] = {msg1, msg2};
 
-       struct i2c_msg msg1 = { tpm_dev.client->addr, 0, 1, &addr };
-       struct i2c_msg msg2 = { tpm_dev.client->addr, I2C_M_RD, len, buffer };
-
-       int rc;
+       int rc = 0;
        int count;
 
        /* Lock the adapter for the duration of the whole sequence. */
@@ -101,30 +118,49 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
                return -EOPNOTSUPP;
        i2c_lock_adapter(tpm_dev.client->adapter);
 
-       for (count = 0; count < MAX_COUNT; count++) {
-               rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
-               if (rc > 0)
-                       break;  /* break here to skip sleep */
-
-               usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
-       }
-
-       if (rc <= 0)
-               goto out;
-
-       /* After the TPM has successfully received the register address it needs
-        * some time, thus we're sleeping here again, before retrieving the data
-        */
-       for (count = 0; count < MAX_COUNT; count++) {
-               usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
-               rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
-               if (rc > 0)
-                       break;
+       if (tpm_dev.chip_type == SLB9645) {
+               /* use a combined read for newer chips
+                * unfortunately the smbus functions are not suitable due to
+                * the 32 byte limit of the smbus.
+                * retries should usually not be needed, but are kept just to
+                * be on the safe side.
+               */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       rc = __i2c_transfer(tpm_dev.client->adapter, msgs, 2);
+                       if (rc > 0)
+                               break;  /* break here to skip sleep */
+                       usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+               }
+       } else {
+               /* slb9635 protocol should work in all cases */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
+                       if (rc > 0)
+                               break;  /* break here to skip sleep */
+
+                       usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+               }
 
+               if (rc <= 0)
+                       goto out;
+
+               /* After the TPM has successfully received the register address
+                * it needs some time, thus we're sleeping here again, before
+                * retrieving the data
+                */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+                       rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
+                       if (rc > 0)
+                               break;
+               }
        }
 
 out:
        i2c_unlock_adapter(tpm_dev.client->adapter);
+       /* take care of 'guard time' */
+       usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+
        if (rc <= 0)
                return -EIO;
 
@@ -138,7 +174,11 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, 
size_t len,
        int rc = -EIO;
        int count;
 
-       struct i2c_msg msg1 = { tpm_dev.client->addr, 0, len + 1, tpm_dev.buf };
+       struct i2c_msg msg1 = {
+               .addr = tpm_dev.client->addr,
+               .len = len + 1,
+               .buf = tpm_dev.buf,
+        };
 
        if (len > TPM_BUFSIZE)
                return -EINVAL;
@@ -154,16 +194,19 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, 
size_t len,
        /*
         * NOTE: We have to use these special mechanisms here and unfortunately
         * cannot rely on the standard behavior of i2c_transfer.
+        * Even for newer chips the smbus functions are not
+        * suitable due to the 32 byte limit of the smbus.
         */
        for (count = 0; count < max_count; count++) {
                rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
                if (rc > 0)
                        break;
-
                usleep_range(sleep_low, sleep_hi);
        }
 
        i2c_unlock_adapter(tpm_dev.client->adapter);
+       /* take care of 'guard time' */
+       usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
        if (rc <= 0)
                return -EIO;
 
@@ -283,11 +326,18 @@ static int request_locality(struct tpm_chip *chip, int 
loc)
 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
 {
        /* NOTE: since I2C read may fail, return 0 in this case --> time-out */
-       u8 buf;
-       if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
-               return 0;
-       else
-               return buf;
+       u8 buf = 0xFF;
+       u8 i = 0;
+
+       do {
+               if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
+                       return 0;
+
+               i++;
+       /* if locallity is set STS should not be 0xFF */
+       } while ((buf == 0xFF) && i < 10);
+
+       return buf;
 }
 
 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
@@ -328,7 +378,7 @@ static int wait_for_stat(struct tpm_chip *chip, u8 mask, 
unsigned long timeout,
 
        /* check current status */
        *status = tpm_tis_i2c_status(chip);
-       if ((*status & mask) == mask)
+       if ((*status != 0xFF) && (*status & mask) == mask)
                return 0;
 
        stop = jiffies + timeout;
@@ -372,7 +422,6 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t 
count)
                /* avoid endless loop in case of broken HW */
                if (retries > MAX_COUNT_LONG)
                        return -EIO;
-
        }
        return size;
 }
@@ -480,7 +529,6 @@ static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, 
size_t len)
                        rc = -EIO;
                        goto out_err;
                }
-
        }
 
        /* write last byte */
@@ -568,6 +616,7 @@ static int tpm_tis_i2c_init(struct device *dev)
 
        chip = tpm_register_hardware(dev, &tpm_tis_i2c);
        if (!chip) {
+               dev_err(dev, "could not register hardware\n");
                rc = -ENODEV;
                goto out_err;
        }
@@ -582,20 +631,24 @@ static int tpm_tis_i2c_init(struct device *dev)
        chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 
        if (request_locality(chip, 0) != 0) {
+               dev_err(dev, "could not request locality\n");
                rc = -ENODEV;
                goto out_vendor;
        }
 
        /* read four bytes from DID_VID register */
        if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
+               dev_err(dev, "could not read vendor id\n");
                rc = -EIO;
                goto out_release;
        }
 
-       /* create DID_VID register value, after swapping to little-endian */
-       vendor = be32_to_cpu((__be32) vendor);
-
-       if (vendor != TPM_TIS_I2C_DID_VID) {
+       if (vendor == TPM_TIS_I2C_DID_VID_9645) {
+               tpm_dev.chip_type = SLB9645;
+       } else if (vendor == TPM_TIS_I2C_DID_VID_9635) {
+               tpm_dev.chip_type = SLB9635;
+       } else {
+               dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
                rc = -ENODEV;
                goto out_release;
        }
@@ -631,22 +684,38 @@ out_err:
 
 static const struct i2c_device_id tpm_tis_i2c_table[] = {
        {"tpm_i2c_infineon", 0},
+       {"slb9635tt", 0},
+       {"slb9645tt", 1},
        {},
 };
 
 MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
+
+#ifdef CONFIG_OF
+static const struct of_device_id tpm_tis_i2c_of_match[] = {
+       { .compatible = "infineon,tpm_i2c_infineon", .data = (void *)0 },
+       { .compatible = "infineon,slb9635tt", .data = (void *)0 },
+       { .compatible = "infineon,slb9645tt", .data = (void *)1 },
+       {},
+};
+MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
+#endif
+
 static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
 
 static int tpm_tis_i2c_probe(struct i2c_client *client,
                             const struct i2c_device_id *id)
 {
        int rc;
-       if (tpm_dev.client != NULL)
+       struct device *dev = &(client->dev);
+
+       if (tpm_dev.client != NULL) {
+               dev_err(dev, "This driver only supports one client at a 
time\n");
                return -EBUSY;  /* We only support one client */
+       }
 
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
-               dev_err(&client->dev,
-                       "no algorithms associated to the i2c bus\n");
+               dev_err(dev, "no algorithms associated to the i2c bus\n");
                return -ENODEV;
        }
 
@@ -682,7 +751,6 @@ static int tpm_tis_i2c_remove(struct i2c_client *client)
 }
 
 static struct i2c_driver tpm_tis_i2c_driver = {
-
        .id_table = tpm_tis_i2c_table,
        .probe = tpm_tis_i2c_probe,
        .remove = tpm_tis_i2c_remove,
@@ -690,11 +758,12 @@ static struct i2c_driver tpm_tis_i2c_driver = {
                   .name = "tpm_i2c_infineon",
                   .owner = THIS_MODULE,
                   .pm = &tpm_tis_i2c_ops,
+                  .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
                   },
 };
 
 module_i2c_driver(tpm_tis_i2c_driver);
 MODULE_AUTHOR("Peter Huewe <peter.hu...@infineon.com>");
 MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
-MODULE_VERSION("2.1.5");
+MODULE_VERSION("2.2.0");
 MODULE_LICENSE("GPL");
-- 
1.7.11.msysgit.0

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