[PATCH 1/2] char/tpm: Add new driver for Infineon I2C TIS TPM

* [PATCH 1/2] char/tpm: Add new driver for Infineon I2C TIS TPM
@ 2012-06-12 12:43 Peter Huewe
  2012-06-12 12:43 ` [PATCH 2/2] CHROMIUM: tpm: tpm_i2c_infineon: Lock the I2C adapter for a sequence of requests Peter Huewe
                   ` (3 more replies)
  0 siblings, 4 replies; 12+ messages in thread
From: Peter Huewe @ 2012-06-12 12:43 UTC (permalink / raw)
  To: srajiv
  Cc: tpmdd, tpmdd-devel, linux-kernel, Olof Johansson,
	Luigi Semenzato, andi.shyti, Peter Huewe

This patch adds a driver to support Infineon's SLB 9635 TT 1.2 Soft I2C TPMs
which follow the TGC TIS 1.2 TPM specification[1] and Infineon's I2C Protocol
Stack Specification 0.20.
The I2C Protocol Stack Specification is a simple adaption of the LPC TIS
Protocol to the I2C Bus.
The I2C TPMs can be used when LPC Bus is not available (i.e. non x86
architectures like ARM).

The driver is based on the tpm_tis.c driver by Leendert van Dorn and Kyleen
Hall and has quite similar functionality.

Tested on Nvidia ARM Tegra2 Development Platform and Beagleboard (ARM OMAP)
Tested with the Trousers[2] TSS API Testsuite v 0.3 [3]
Compile-tested on x86 (32/64-bit)

Updates since version 2.1.3:
- use proper probing mechanism
* either add the tpm using I2C_BOARD_INFO to your board file or probe it
* during runtime e.g on BeagleBoard using :
* "echo tpm_i2c_infineon 0x20 > /sys/bus/i2c/devices/i2c-2/new_device"
- fix possible endless loop if hardware misbehaves
- improved return codes
- consistent spelling i2c/tpm -> I2C/TPM
- remove hardcoded sleep values and msleep usage
- removed debug statements
- added check for I2C functionality
- renaming to tpm_i2c_infineon

Updates since version 2.1.2:
- added sysfs entries for duration and timeouts
- updated to new tpm_do_selftest

Updates since version 2.1.0:
- improved error handling
- implemented workarounds needed by the tpm
- fixed typos

References:
[1]
http://www.trustedcomputinggroup.org/resources/pc_client_work_group_pc_client_
specific_tpm_interface_specification_tis_version_12/
[2] http://trousers.sourceforge.net/
[3]
http://sourceforge.net/projects/trousers/files/TSS%20API%20test%20suite/0.3/

Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
---
 drivers/char/tpm/Kconfig            |   11 +
 drivers/char/tpm/Makefile           |    1 +
 drivers/char/tpm/tpm_i2c_infineon.c |  711 +++++++++++++++++++++++++++++++++++
 3 files changed, 723 insertions(+), 0 deletions(-)
 create mode 100644 drivers/char/tpm/tpm_i2c_infineon.c

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index a048199..c4aac48 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -33,6 +33,17 @@ config TCG_TIS
 	  from within Linux.  To compile this driver as a module, choose
 	  M here; the module will be called tpm_tis.
 
+config TCG_TIS_I2C_INFINEON
+	tristate "TPM Interface Specification 1.2 Interface (I2C - Infineon)"
+	depends on I2C
+	---help---
+	  If you have a TPM security chip that is compliant with the
+	  TCG TIS 1.2 TPM specification and Infineon's I2C Protocol Stack
+	  Specification 0.20 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_tis_i2c_infineon.
+
 config TCG_NSC
 	tristate "National Semiconductor TPM Interface"
 	depends on X86
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index ea3a1e0..a9c3afc 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -6,6 +6,7 @@ ifdef CONFIG_ACPI
 	obj-$(CONFIG_TCG_TPM) += tpm_bios.o
 endif
 obj-$(CONFIG_TCG_TIS) += tpm_tis.o
+obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
 obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
 obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
 obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
new file mode 100644
index 0000000..54b9a5e
--- /dev/null
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -0,0 +1,711 @@
+/*
+ * Copyright (C) 2012 Infineon Technologies
+ *
+ * Authors:
+ * Peter Huewe <peter.huewe@infineon.com>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
+ * Infineon I2C Protocol Stack Specification v0.20.
+ *
+ * It is based on the original tpm_tis device driver from Leendert van
+ * Dorn and Kyleen Hall.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ *
+ */
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/wait.h>
+#include "tpm.h"
+
+/* max. buffer size supported by our TPM */
+#define TPM_BUFSIZE 1260
+
+/* max. number of iterations after I2C NAK */
+#define MAX_COUNT 3
+
+#define SLEEP_DURATION_LOW 55
+#define SLEEP_DURATION_HI 65
+
+/* max. number of iterations after I2C NAK for 'long' commands
+ * we need this especially for sending TPM_READY, since the cleanup after the
+ * transtion to the ready state may take some time, but it is unpredictable
+ * how long it will take.
+ */
+#define MAX_COUNT_LONG 50
+
+#define SLEEP_DURATION_LONG_LOW 200
+#define SLEEP_DURATION_LONG_HI 220
+
+/* After sending TPM_READY to 'reset' the TPM we have to sleep even longer */
+#define SLEEP_DURATION_RESET_LOW 2400
+#define SLEEP_DURATION_RESET_HI 2600
+
+/* we want to use usleep_range instead of msleep for the 5ms TPM_TIMEOUT */
+#define TPM_TIMEOUT_US_LOW (TPM_TIMEOUT * 1000)
+#define TPM_TIMEOUT_US_HI  (TPM_TIMEOUT_US_LOW + 2000)
+
+/* expected value for DIDVID register */
+#define TPM_TIS_I2C_DID_VID 0x000b15d1L
+
+/* 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;
+};
+
+static struct tpm_inf_dev tpm_dev;
+static struct i2c_driver tpm_tis_i2c_driver;
+
+/*
+ * iic_tpm_read() - read from TPM register
+ * @addr: register address to read from
+ * @buffer: provided by caller
+ * @len: number of bytes to read
+ *
+ * Read len bytes from TPM register and put them into
+ * buffer (little-endian format, i.e. first byte is put into buffer[0]).
+ *
+ * NOTE: TPM is big-endian for multi-byte values. Multi-byte
+ * values have to be swapped.
+ *
+ * NOTE: We can't unfortunately use the combined read/write functions
+ * provided by the i2c core as the TPM currently does not support the
+ * repeated start condition and due to it's special requirements.
+ * The i2c_smbus* functions do not work for this chip.
+ *
+ * Return -EIO on error, 0 on success.
+ */
+static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
+{
+
+	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 count;
+
+	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)
+		return -EIO;
+
+	/* 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 (rc <= 0)
+		return -EIO;
+
+	return 0;
+}
+
+static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
+				 unsigned int sleep_low,
+				 unsigned int sleep_hi, u8 max_count)
+{
+	int rc = -EIO;
+	int count;
+
+	struct i2c_msg msg1 = { tpm_dev.client->addr, 0, len + 1, tpm_dev.buf };
+
+	if (len > TPM_BUFSIZE)
+		return -EINVAL;
+
+	/* prepend the 'register address' to the buffer */
+	tpm_dev.buf[0] = addr;
+	memcpy(&(tpm_dev.buf[1]), buffer, len);
+
+	/*
+	 * NOTE: We have to use these special mechanisms here and unfortunately
+	 * cannot rely on the standard behavior of i2c_transfer.
+	 */
+	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);
+	}
+
+	if (rc <= 0)
+		return -EIO;
+
+	return 0;
+}
+
+/*
+ * iic_tpm_write() - write to TPM register
+ * @addr: register address to write to
+ * @buffer: containing data to be written
+ * @len: number of bytes to write
+ *
+ * Write len bytes from provided buffer to TPM register (little
+ * endian format, i.e. buffer[0] is written as first byte).
+ *
+ * NOTE: TPM is big-endian for multi-byte values. Multi-byte
+ * values have to be swapped.
+ *
+ * NOTE: use this function instead of the iic_tpm_write_generic function.
+ *
+ * Return -EIO on error, 0 on success
+ */
+static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
+{
+	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LOW,
+				     SLEEP_DURATION_HI, MAX_COUNT);
+}
+
+/*
+ * This function is needed especially for the cleanup situation after
+ * sending TPM_READY
+ * */
+static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
+{
+	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG_LOW,
+				     SLEEP_DURATION_LONG_HI, MAX_COUNT_LONG);
+}
+
+enum tis_access {
+	TPM_ACCESS_VALID = 0x80,
+	TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
+	TPM_ACCESS_REQUEST_PENDING = 0x04,
+	TPM_ACCESS_REQUEST_USE = 0x02,
+};
+
+enum tis_status {
+	TPM_STS_VALID = 0x80,
+	TPM_STS_COMMAND_READY = 0x40,
+	TPM_STS_GO = 0x20,
+	TPM_STS_DATA_AVAIL = 0x10,
+	TPM_STS_DATA_EXPECT = 0x08,
+};
+
+enum tis_defaults {
+	TIS_SHORT_TIMEOUT = 750,	/* ms */
+	TIS_LONG_TIMEOUT = 2000,	/* 2 sec */
+};
+
+#define	TPM_ACCESS(l)			(0x0000 | ((l) << 4))
+#define	TPM_STS(l)			(0x0001 | ((l) << 4))
+#define	TPM_DATA_FIFO(l)		(0x0005 | ((l) << 4))
+#define	TPM_DID_VID(l)			(0x0006 | ((l) << 4))
+
+static int check_locality(struct tpm_chip *chip, int loc)
+{
+	u8 buf;
+	int rc;
+
+	rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
+	if (rc < 0)
+		return rc;
+
+	if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
+		chip->vendor.locality = loc;
+		return loc;
+	}
+
+	return -EIO;
+}
+
+/* implementation similar to tpm_tis */
+static void release_locality(struct tpm_chip *chip, int loc, int force)
+{
+	u8 buf;
+	if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
+		return;
+
+	if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
+	    (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) {
+		buf = TPM_ACCESS_ACTIVE_LOCALITY;
+		iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
+	}
+}
+
+static int request_locality(struct tpm_chip *chip, int loc)
+{
+	unsigned long stop;
+	u8 buf = TPM_ACCESS_REQUEST_USE;
+
+	if (check_locality(chip, loc) >= 0)
+		return loc;
+
+	iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
+
+	/* wait for burstcount */
+	stop = jiffies + chip->vendor.timeout_a;
+	do {
+		if (check_locality(chip, loc) >= 0)
+			return loc;
+		usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
+	} while (time_before(jiffies, stop));
+
+	return -ETIME;
+}
+
+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;
+}
+
+static void tpm_tis_i2c_ready(struct tpm_chip *chip)
+{
+	/* this causes the current command to be aborted */
+	u8 buf = TPM_STS_COMMAND_READY;
+	iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
+}
+
+static ssize_t get_burstcount(struct tpm_chip *chip)
+{
+	unsigned long stop;
+	ssize_t burstcnt;
+	u8 buf[3];
+
+	/* wait for burstcount */
+	/* which timeout value, spec has 2 answers (c & d) */
+	stop = jiffies + chip->vendor.timeout_d;
+	do {
+		/* Note: STS is little endian */
+		if (iic_tpm_read(TPM_STS(chip->vendor.locality)+1, buf, 3) < 0)
+			burstcnt = 0;
+		else
+			burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
+
+		if (burstcnt)
+			return burstcnt;
+
+		usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
+	} while (time_before(jiffies, stop));
+	return -EBUSY;
+}
+
+static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+			 int *status)
+{
+	unsigned long stop;
+
+	/* check current status */
+	*status = tpm_tis_i2c_status(chip);
+	if ((*status & mask) == mask)
+		return 0;
+
+	stop = jiffies + timeout;
+	do {
+		/* since we just checked the status, give the TPM some time */
+		usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
+		*status = tpm_tis_i2c_status(chip);
+		if ((*status & mask) == mask)
+			return 0;
+
+	} while (time_before(jiffies, stop));
+
+	return -ETIME;
+}
+
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	size_t size = 0;
+	ssize_t burstcnt;
+	u8 retries = 0;
+	int rc;
+
+	while (size < count) {
+		burstcnt = get_burstcount(chip);
+
+		/* burstcnt < 0 = TPM is busy */
+		if (burstcnt < 0)
+			return burstcnt;
+
+		/* limit received data to max. left */
+		if (burstcnt > (count - size))
+			burstcnt = count - size;
+
+		rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
+				  &(buf[size]), burstcnt);
+		if (rc == 0)
+			size += burstcnt;
+		else if (rc < 0)
+			retries++;
+
+		/* avoid endless loop in case of broken HW */
+		if (retries > MAX_COUNT_LONG)
+			return -EIO;
+
+	}
+	return size;
+}
+
+static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	int size = 0;
+	int expected, status;
+
+	if (count < TPM_HEADER_SIZE) {
+		size = -EIO;
+		goto out;
+	}
+
+	/* read first 10 bytes, including tag, paramsize, and result */
+	size = recv_data(chip, buf, TPM_HEADER_SIZE);
+	if (size < TPM_HEADER_SIZE) {
+		dev_err(chip->dev, "Unable to read header\n");
+		goto out;
+	}
+
+	expected = be32_to_cpu(*(__be32 *)(buf + 2));
+	if ((size_t) expected > count) {
+		size = -EIO;
+		goto out;
+	}
+
+	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
+			  expected - TPM_HEADER_SIZE);
+	if (size < expected) {
+		dev_err(chip->dev, "Unable to read remainder of result\n");
+		size = -ETIME;
+		goto out;
+	}
+
+	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
+	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
+		dev_err(chip->dev, "Error left over data\n");
+		size = -EIO;
+		goto out;
+	}
+
+out:
+	tpm_tis_i2c_ready(chip);
+	/* The TPM needs some time to clean up here,
+	 * so we sleep rather than keeping the bus busy
+	 */
+	usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
+	release_locality(chip, chip->vendor.locality, 0);
+	return size;
+}
+
+static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	int rc, status;
+	ssize_t burstcnt;
+	size_t count = 0;
+	u8 retries = 0;
+	u8 sts = TPM_STS_GO;
+
+	if (len > TPM_BUFSIZE)
+		return -E2BIG;	/* command is too long for our tpm, sorry */
+
+	if (request_locality(chip, 0) < 0)
+		return -EBUSY;
+
+	status = tpm_tis_i2c_status(chip);
+	if ((status & TPM_STS_COMMAND_READY) == 0) {
+		tpm_tis_i2c_ready(chip);
+		if (wait_for_stat
+		    (chip, TPM_STS_COMMAND_READY,
+		     chip->vendor.timeout_b, &status) < 0) {
+			rc = -ETIME;
+			goto out_err;
+		}
+	}
+
+	while (count < len - 1) {
+		burstcnt = get_burstcount(chip);
+
+		/* burstcnt < 0 = TPM is busy */
+		if (burstcnt < 0)
+			return burstcnt;
+
+		if (burstcnt > (len - 1 - count))
+			burstcnt = len - 1 - count;
+
+		rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
+				   &(buf[count]), burstcnt);
+		if (rc == 0)
+			count += burstcnt;
+		else if (rc < 0)
+			retries++;
+
+		/* avoid endless loop in case of broken HW */
+		if (retries > MAX_COUNT_LONG) {
+			rc = -EIO;
+			goto out_err;
+		}
+
+		wait_for_stat(chip, TPM_STS_VALID,
+			      chip->vendor.timeout_c, &status);
+
+		if ((status & TPM_STS_DATA_EXPECT) == 0) {
+			rc = -EIO;
+			goto out_err;
+		}
+
+	}
+
+	/* write last byte */
+	iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
+	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
+	if ((status & TPM_STS_DATA_EXPECT) != 0) {
+		rc = -EIO;
+		goto out_err;
+	}
+
+	/* go and do it */
+	iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
+
+	return len;
+out_err:
+	tpm_tis_i2c_ready(chip);
+	/* The TPM needs some time to clean up here,
+	 * so we sleep rather than keeping the bus busy
+	 */
+	usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
+	release_locality(chip, chip->vendor.locality, 0);
+	return rc;
+}
+
+static const struct file_operations tis_ops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.open = tpm_open,
+	.read = tpm_read,
+	.write = tpm_write,
+	.release = tpm_release,
+};
+
+static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
+static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
+static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL);
+static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL);
+static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL);
+static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated, NULL);
+static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps_1_2, NULL);
+static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
+static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
+static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
+
+static struct attribute *tis_attrs[] = {
+	&dev_attr_pubek.attr,
+	&dev_attr_pcrs.attr,
+	&dev_attr_enabled.attr,
+	&dev_attr_active.attr,
+	&dev_attr_owned.attr,
+	&dev_attr_temp_deactivated.attr,
+	&dev_attr_caps.attr,
+	&dev_attr_cancel.attr,
+	&dev_attr_durations.attr,
+	&dev_attr_timeouts.attr,
+	NULL,
+};
+
+static struct attribute_group tis_attr_grp = {
+	.attrs = tis_attrs
+};
+
+static struct tpm_vendor_specific tpm_tis_i2c = {
+	.status = tpm_tis_i2c_status,
+	.recv = tpm_tis_i2c_recv,
+	.send = tpm_tis_i2c_send,
+	.cancel = tpm_tis_i2c_ready,
+	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_canceled = TPM_STS_COMMAND_READY,
+	.attr_group = &tis_attr_grp,
+	.miscdev.fops = &tis_ops,
+};
+
+static int __devinit tpm_tis_i2c_init(struct device *dev)
+{
+	u32 vendor;
+	int rc = 0;
+	struct tpm_chip *chip;
+
+	chip = tpm_register_hardware(dev, &tpm_tis_i2c);
+	if (!chip) {
+		rc = -ENODEV;
+		goto out_err;
+	}
+
+	/* Disable interrupts */
+	chip->vendor.irq = 0;
+
+	/* Default timeouts */
+	chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+	chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
+	chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+	chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+
+	if (request_locality(chip, 0) != 0) {
+		rc = -ENODEV;
+		goto out_vendor;
+	}
+
+	/* read four bytes from DID_VID register */
+	if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
+		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) {
+		rc = -ENODEV;
+		goto out_release;
+	}
+
+	dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
+
+	INIT_LIST_HEAD(&chip->vendor.list);
+	tpm_dev.chip = chip;
+
+	tpm_get_timeouts(chip);
+	tpm_do_selftest(chip);
+
+	return 0;
+
+out_release:
+	release_locality(chip, chip->vendor.locality, 1);
+
+out_vendor:
+	/* close file handles */
+	tpm_dev_vendor_release(chip);
+
+	/* remove hardware */
+	tpm_remove_hardware(chip->dev);
+
+	/* reset these pointers, otherwise we oops */
+	chip->dev->release = NULL;
+	chip->release = NULL;
+	tpm_dev.client = NULL;
+	dev_set_drvdata(chip->dev, chip);
+out_err:
+	return rc;
+}
+
+static const struct i2c_device_id tpm_tis_i2c_table[] = {
+	{"tpm_i2c_infineon", 0},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
+
+#ifdef CONFIG_PM
+/* NOTE:
+ * Suspend does currently not work Nvidias Tegra2 Platform
+ * but works fine on Beagleboard (arm omap).
+ *
+ * This function will block System Suspend if TPM is not initialized,
+ * however the TPM is usually initialized by BIOS/u-boot or by sending
+ * a TPM_Startup command.
+ */
+static int tpm_tis_i2c_suspend(struct device *dev)
+{
+	return tpm_pm_suspend(dev, dev->power.power_state);
+}
+
+static int tpm_tis_i2c_resume(struct device *dev)
+{
+	return tpm_pm_resume(dev);
+}
+
+static const struct dev_pm_ops tpm_tis_i2c_ops = {
+	.suspend = tpm_tis_i2c_suspend,
+	.resume = tpm_tis_i2c_resume,
+};
+#else
+#define tpm_tis_i2c_suspend NULL
+#define tpm_tis_i2c_resume NULL
+#define tpm_tis_i2c_ops NULL
+#endif
+
+static int __devinit tpm_tis_i2c_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	int rc;
+	if (tpm_dev.client != NULL)
+		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");
+		return -ENODEV;
+	}
+
+	client->driver = &tpm_tis_i2c_driver;
+	tpm_dev.client = client;
+	rc = tpm_tis_i2c_init(&client->dev);
+	if (rc != 0) {
+		client->driver = NULL;
+		tpm_dev.client = NULL;
+		rc = -ENODEV;
+	}
+	return rc;
+}
+
+static int __devexit tpm_tis_i2c_remove(struct i2c_client *client)
+{
+	struct tpm_chip *chip = tpm_dev.chip;
+	release_locality(chip, chip->vendor.locality, 1);
+
+	/* close file handles */
+	tpm_dev_vendor_release(chip);
+
+	/* remove hardware */
+	tpm_remove_hardware(chip->dev);
+
+	/* reset these pointers, otherwise we oops */
+	chip->dev->release = NULL;
+	chip->release = NULL;
+	tpm_dev.client = NULL;
+	dev_set_drvdata(chip->dev, chip);
+
+	return 0;
+}
+
+static struct i2c_driver tpm_tis_i2c_driver = {
+
+	.id_table = tpm_tis_i2c_table,
+	.probe = tpm_tis_i2c_probe,
+	.remove = tpm_tis_i2c_remove,
+	.driver = {
+		   .name = "tpm_i2c_infineon",
+		   .owner = THIS_MODULE,
+		   .pm = &tpm_tis_i2c_ops,
+		   },
+};
+
+module_i2c_driver(tpm_tis_i2c_driver);
+MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
+MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
+MODULE_VERSION("2.1.4");
+MODULE_LICENSE("GPL");
-- 
1.7.6.msysgit.0


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