TPM: STMicroelectronics ST33 I2C KERNEL 3.x

 * STMicroelectronics version 1.2.0, Copyright (C) 2010
 * STMicroelectronics comes with ABSOLUTELY NO WARRANTY.
 * This is free software, and you are welcome to redistribute it
 * under certain conditions.

This is the driver for TPM chip from ST Microelectronics.

If you have a TPM security chip from STMicroelectronics working with
an I2C, in menuconfig or .config choose the tpm driver on
device --> tpm and activate the protocol of your choice before compiling
the kernel.
The driver will be accessible from within Linux.

Tested on linux x86/x64 on kernel 3.x

Signed-off-by: Mathias Leblanc <mathias.leblanc@st.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

2 files changed, 984 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_stm_st33_i2c.c b/drivers/char/tpm/tpm_stm_st33_i2c.c
new file mode 100644
index 000000000000..32cdd5e92141
--- /dev/null
+++ b/drivers/char/tpm/tpm_stm_st33_i2c.c
@@ -0,0 +1,903 @@
+/*
+ * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
+ * Copyright (C) 2009, 2010  STMicroelectronics
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * STMicroelectronics version 1.2.0, Copyright (C) 2010
+ * STMicroelectronics comes with ABSOLUTELY NO WARRANTY.
+ * This is free software, and you are welcome to redistribute it
+ * under certain conditions.
+ *
+ * @Author: Christophe RICARD tpmsupport@st.com
+ *
+ * @File: tpm_stm_st33_i2c.c
+ *
+ * @Synopsis:
+ *      09/15/2010:     First shot driver tpm_tis driver for
+                         lpc is used as model.
+ */
+
+#include <linux/i2c/tpm_stm_st33_i2c.h>
+
+#include "tpm_stm_st33_i2c.h"
+
+enum stm33zp24_access {
+        TPM_ACCESS_VALID = 0x80,
+        TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
+        TPM_ACCESS_REQUEST_PENDING = 0x04,
+        TPM_ACCESS_REQUEST_USE = 0x02,
+};
+
+enum stm33zp24_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 stm33zp24_int_flags {
+        TPM_GLOBAL_INT_ENABLE = 0x80,
+        TPM_INTF_CMD_READY_INT = 0x080,
+        TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
+        TPM_INTF_WAKE_UP_READY_INT = 0x020,
+        TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
+        TPM_INTF_STS_VALID_INT = 0x002,
+        TPM_INTF_DATA_AVAIL_INT = 0x001,
+};
+
+enum tis_defaults {
+        TIS_SHORT_TIMEOUT = 750,
+        TIS_LONG_TIMEOUT = 2000,
+};
+
+/*
+ * write8_reg
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, The length of the data
+ * @return: Returns negative errno, or else the number of bytes written.
+ */
+static int write8_reg(struct i2c_client *client, u8 tpm_register,
+                      u8 *tpm_data, u16 tpm_size)
+{
+        u8 data;
+        int value = 0;
+        struct st33zp24_platform_data *pin_infos;
+
+        pin_infos = client->dev.platform_data;
+
+        data = tpm_register;
+        memcpy(pin_infos->tpm_i2c_buffer[0], &data, sizeof(data));
+        memcpy(pin_infos->tpm_i2c_buffer[0] + 1, tpm_data, tpm_size);
+        value = i2c_master_send(client, pin_infos->tpm_i2c_buffer[0],
+                                tpm_size + 1);
+        return value;
+} /* write8_reg() */
+
+/*
+ * read8_reg
+ * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm_register, the tpm tis register where the data should be read
+ * @param: tpm_data, the TPM response
+ * @param: tpm_size, tpm TPM response size to read.
+ * @return: number of byte read successfully: should be one if success.
+ */
+static int read8_reg(struct i2c_client *client, u8 tpm_register,
+                    u8 *tpm_data, int tpm_size)
+{
+        u8 status = 0;
+        u8 data;
+        struct st33zp24_platform_data *pin_infos;
+
+        pin_infos = client->dev.platform_data;
+
+        data = TPM_DUMMY_BYTE;
+        status = write8_reg(client, tpm_register, &data, 1);
+        if (status == 2)
+                status = i2c_master_recv(client, tpm_data, tpm_size);
+        return status;
+} /* read8_reg() */
+
+/*
+ * I2C_WRITE_DATA
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: client, the chip description
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, The length of the data
+ * @return: number of byte written successfully: should be one if success.
+ */
+#define I2C_WRITE_DATA(client, tpm_register, tpm_data, tpm_size) \
+        (write8_reg(client, tpm_register | \
+        TPM_WRITE_DIRECTION, tpm_data, tpm_size))
+
+/*
+ * I2C_READ_DATA
+ * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm, the chip description
+ * @param: tpm_register, the tpm tis register where the data should be read
+ * @param: tpm_data, the TPM response
+ * @param: tpm_size, tpm TPM response size to read.
+ * @return: number of byte read successfully: should be one if success.
+ */
+#define I2C_READ_DATA(client, tpm_register, tpm_data, tpm_size) \
+        (read8_reg(client, tpm_register, tpm_data, tpm_size))
+
+/*
+ * clear_interruption
+ * clear the TPM interrupt register.
+ * @param: tpm, the chip description
+ */
+static void clear_interruption(struct i2c_client *client)
+{
+        u8 interrupt;
+        I2C_READ_DATA(client, TPM_INT_STATUS, &interrupt, 1);
+        I2C_WRITE_DATA(client, TPM_INT_STATUS, &interrupt, 1);
+        I2C_READ_DATA(client, TPM_INT_STATUS, &interrupt, 1);
+} /* clear_interruption() */
+
+/*
+ * _wait_for_interrupt_serirq_timeout
+ * @param: tpm, the chip description
+ * @param: timeout, the timeout of the interrupt
+ * @return: the status of the interruption.
+ */
+static long _wait_for_interrupt_serirq_timeout(struct tpm_chip *chip,
+                                                unsigned long timeout)
+{
+        long status;
+        struct i2c_client *client;
+        struct st33zp24_platform_data *pin_infos;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+        pin_infos = client->dev.platform_data;
+
+        status = wait_for_completion_interruptible_timeout(
+                                        &pin_infos->irq_detection,
+                                                timeout);
+        if (status > 0)
+                enable_irq(gpio_to_irq(pin_infos->io_serirq));
+        gpio_direction_input(pin_infos->io_serirq);
+
+        return status;
+} /* wait_for_interrupt_serirq_timeout() */
+
+int wait_for_serirq_timeout(struct tpm_chip *chip, bool condition,
+                                 unsigned long timeout)
+{
+        int status = 2;
+        struct i2c_client *client;
+        struct st33zp24_platform_data *pin_infos;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+        pin_infos = client->dev.platform_data;
+
+        status = _wait_for_interrupt_serirq_timeout(chip, timeout);
+        if (!status) {
+                status = -EBUSY;
+        } else{
+                clear_interruption(client);
+                if (condition)
+                        status = 1;
+        }
+        return status;
+}
+
+/*
+ * tpm_stm_i2c_cancel, cancel is not implemented.
+ * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
+ */
+static void tpm_stm_i2c_cancel(struct tpm_chip *chip)
+{
+        struct i2c_client *client;
+        u8 data;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+
+        data = TPM_STS_COMMAND_READY;
+        I2C_WRITE_DATA(client, TPM_STS, &data, 1);
+        if (chip->vendor.irq)
+                wait_for_serirq_timeout(chip, 1, chip->vendor.timeout_a);
+}       /* tpm_stm_i2c_cancel() */
+
+/*
+ * tpm_stm_spi_status return the TPM_STS register
+ * @param: chip, the tpm chip description
+ * @return: the TPM_STS register value.
+ */
+static u8 tpm_stm_i2c_status(struct tpm_chip *chip)
+{
+        struct i2c_client *client;
+        u8 data;
+        client = (struct i2c_client *) chip->vendor.iobase;
+
+        I2C_READ_DATA(client, TPM_STS, &data, 1);
+        return data;
+}                               /* tpm_stm_i2c_status() */
+
+
+/*
+ * check_locality if the locality is active
+ * @param: chip, the tpm chip description
+ * @return: the active locality or -EACCESS.
+ */
+static int check_locality(struct tpm_chip *chip)
+{
+        struct i2c_client *client;
+        u8 data;
+        u8 status;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+
+        status = I2C_READ_DATA(client, TPM_ACCESS, &data, 1);
+        if (status && (data &
+                (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+                (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
+                return chip->vendor.locality;
+
+        return -EACCES;
+
+} /* check_locality() */
+
+/*
+ * request_locality request the TPM locality
+ * @param: chip, the chip description
+ * @return: the active locality or EACCESS.
+ */
+static int request_locality(struct tpm_chip *chip)
+{
+        unsigned long stop;
+        long rc;
+        struct i2c_client *client;
+        u8 data;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+
+        if (check_locality(chip) == chip->vendor.locality)
+                return chip->vendor.locality;
+
+        data = TPM_ACCESS_REQUEST_USE;
+        rc = I2C_WRITE_DATA(client, TPM_ACCESS, &data, 1);
+        if (rc < 0)
+                goto end;
+
+        if (chip->vendor.irq) {
+                rc = wait_for_serirq_timeout(chip, (check_locality
+                                                       (chip) >= 0),
+                                                      chip->vendor.timeout_a);
+                if (rc > 0)
+                        return chip->vendor.locality;
+        } else{
+                stop = jiffies + chip->vendor.timeout_a;
+                do {
+                        if (check_locality(chip) >= 0)
+                                return chip->vendor.locality;
+                        msleep(TPM_TIMEOUT);
+                } while (time_before(jiffies, stop));
+        }
+        rc = -EACCES;
+end:
+        return rc;
+} /* request_locality() */
+
+/*
+ * release_locality release the active locality
+ * @param: chip, the tpm chip description.
+ */
+static void release_locality(struct tpm_chip *chip)
+{
+        struct i2c_client *client;
+        u8 data;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+        data = TPM_ACCESS_ACTIVE_LOCALITY;
+
+        I2C_WRITE_DATA(client, TPM_ACCESS, &data, 1);
+}
+
+/*
+ * get_burstcount return the burstcount address 0x19 0x1A
+ * @param: chip, the chip description
+ * return: the burstcount.
+ */
+static int get_burstcount(struct tpm_chip *chip)
+{
+        unsigned long stop;
+        int burstcnt, status;
+        u8 tpm_reg, temp;
+
+        struct i2c_client *client = (struct i2c_client *) chip->vendor.iobase;
+
+        stop = jiffies + chip->vendor.timeout_d;
+        do {
+                tpm_reg = TPM_STS + 1;
+                status = I2C_READ_DATA(client, tpm_reg, &temp, 1);
+                if (status < 0)
+                        goto end;
+
+                tpm_reg = tpm_reg + 1;
+                burstcnt = temp;
+                status = I2C_READ_DATA(client, tpm_reg, &temp, 1);
+                if (status < 0)
+                        goto end;
+
+                burstcnt |= temp << 8;
+                if (burstcnt)
+                        return burstcnt;
+                msleep(TPM_TIMEOUT);
+        } while (time_before(jiffies, stop));
+
+end:
+        return -EBUSY;
+} /* get_burstcount() */
+
+/*
+ * wait_for_stat wait for a TPM_STS value
+ * @param: chip, the tpm chip description
+ * @param: mask, the value mask to wait
+ * @param: timeout, the timeout
+ * @param: queue, the wait queue.
+ * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
+ */
+static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+                         wait_queue_head_t *queue)
+{
+        unsigned long stop;
+        long rc;
+        u8 status;
+
+         if (chip->vendor.irq) {
+                rc = wait_for_serirq_timeout(chip, ((tpm_stm_i2c_status
+                                                        (chip) & mask) ==
+                                                       mask), timeout);
+                if (rc > 0)
+                        return 0;
+        } else{
+                stop = jiffies + timeout;
+                do {
+                        msleep(TPM_TIMEOUT);
+                        status = tpm_stm_i2c_status(chip);
+                        if ((status & mask) == mask)
+                                return 0;
+                } while (time_before(jiffies, stop));
+        }
+        return -ETIME;
+} /* wait_for_stat() */
+
+/*
+ * recv_data receive data
+ * @param: chip, the tpm chip description
+ * @param: buf, the buffer where the data are received
+ * @param: count, the number of data to receive
+ * @return: the number of bytes read from TPM FIFO.
+ */
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+        int size = 0, burstcnt, len;
+        struct i2c_client *client;
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+
+        while (size < count &&
+               wait_for_stat(chip,
+                             TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+                             chip->vendor.timeout_c,
+                             &chip->vendor.read_queue)
+               == 0) {
+                burstcnt = get_burstcount(chip);
+                len = min_t(int, burstcnt, count - size);
+                I2C_READ_DATA(client, TPM_DATA_FIFO, buf + size, len);
+                size += len;
+        }
+        return size;
+}
+
+/*
+ * tpm_ioserirq_handler the serirq irq handler
+ * @param: irq, the tpm chip description
+ * @param: dev_id, the description of the chip
+ * @return: the status of the handler.
+ */
+static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
+{
+        struct tpm_chip *chip = dev_id;
+        struct i2c_client *client;
+        struct st33zp24_platform_data *pin_infos;
+
+        disable_irq_nosync(irq);
+
+        client = (struct i2c_client *) chip->vendor.iobase;
+        pin_infos = client->dev.platform_data;
+
+        complete(&pin_infos->irq_detection);
+        return IRQ_HANDLED;
+} /* tpm_ioserirq_handler() */
+
+
+/*
+ * tpm_stm_i2c_send send TPM commands through the I2C bus.
+ *
+ * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
+ * @param: buf, the buffer to send.
+ * @param: count, the number of bytes to send.
+ * @return: In case of success the number of bytes sent.
+ *                      In other case, a < 0 value describing the issue.
+ */
+static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf,
+                            size_t len)
+{
+        u32 ret = 0, ordinal,
+            status,
+            burstcnt = 0, i, size;
+        u8 data;
+        struct i2c_client *client;
+        struct st33zp24_platform_data *pin_infos;
+
+        if (chip == NULL)
+                return -EBUSY;
+        if (len < TPM_HEADER_SIZE)
+                return -EBUSY;
+
+        client = (struct i2c_client *)chip->vendor.iobase;
+        pin_infos = client->dev.platform_data;
+
+        ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+
+        client->flags = 0;
+
+        ret = request_locality(chip);
+        if (ret < 0)
+                return ret;
+
+        status = tpm_stm_i2c_status(chip);
+        if ((status & TPM_STS_COMMAND_READY) == 0) {
+                tpm_stm_i2c_cancel(chip);
+                if (wait_for_stat
+                    (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
+                     &chip->vendor.int_queue) < 0) {
+                        ret = -ETIME;
+                        goto out_err;
+                }
+        }
+
+        for (i = 0 ; i < len - 1 ;) {
+                burstcnt = get_burstcount(chip);
+                size = min_t(int, len - i - 1, burstcnt);
+                ret = I2C_WRITE_DATA(client, TPM_DATA_FIFO, buf, size);
+                if (ret < 0)
+                        goto out_err;
+
+                i += size;
+        }
+
+        status = tpm_stm_i2c_status(chip);
+        if ((status & TPM_STS_DATA_EXPECT) == 0) {
+                ret = -EIO;
+                goto out_err;
+        }
+
+        ret = I2C_WRITE_DATA(client, TPM_DATA_FIFO, buf + len - 1, 1);
+        if (ret < 0)
+                goto out_err;
+
+        status = tpm_stm_i2c_status(chip);
+        if ((status & TPM_STS_DATA_EXPECT) != 0) {
+                ret = -EIO;
+                goto out_err;
+        }
+
+        data = TPM_STS_GO;
+        I2C_WRITE_DATA(client, TPM_STS, &data, 1);
+
+        return len;
+out_err:
+        tpm_stm_i2c_cancel(chip);
+        release_locality(chip);
+        return ret;
+}
+
+/*
+ * tpm_stm_i2c_recv received TPM response through the I2C bus.
+ * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
+ * @param: buf, the buffer to store datas.
+ * @param: count, the number of bytes to send.
+ * @return: In case of success the number of bytes received.
+ *              In other case, a < 0 value describing the issue.
+ */
+static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
+                            size_t count)
+{
+        int size = 0;
+        int expected;
+
+        struct i2c_client *client;
+        struct st33zp24_platform_data *pin_infos;
+
+        client = (struct i2c_client *)chip->vendor.iobase;
+        pin_infos = client->dev.platform_data;
+
+
+        if (chip == NULL)
+                return -EBUSY;
+
+        if (count < TPM_HEADER_SIZE) {
+                size = -EIO;
+                goto out;
+        }
+
+        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 (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;
+        }
+
+out:
+        chip->vendor.cancel(chip);
+        release_locality(chip);
+        return size;
+}
+
+static const struct file_operations tpm_st33_i2c_fops = {
+        .owner = THIS_MODULE,
+        .llseek = no_llseek,
+        .read = tpm_read,
+        .write = tpm_write,
+        .open = tpm_open,
+        .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 struct attribute *stm_tpm_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, NULL,
+};
+
+static struct attribute_group stm_tpm_attr_grp = {
+        .attrs = stm_tpm_attrs
+};
+
+static struct tpm_vendor_specific st_i2c_tpm = {
+        .send = tpm_stm_i2c_send,
+        .recv = tpm_stm_i2c_recv,
+        .cancel = tpm_stm_i2c_cancel,
+        .status = tpm_stm_i2c_status,
+        .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 = &stm_tpm_attr_grp,
+        .miscdev = {.fops = &tpm_st33_i2c_fops,},
+};
+
+static int interrupts ;
+module_param(interrupts, int, 0444);
+MODULE_PARM_DESC(interrupts, "Enable interrupts");
+
+static int power_mgt = 1;
+module_param(power_mgt, int, 0444);
+MODULE_PARM_DESC(power_mgt, "Power Management");
+
+/*
+ * tpm_st33_i2c_probe initialize the TPM device
+ * @param: client, the i2c_client drescription (TPM I2C description).
+ * @param: id, the i2c_device_id struct.
+ * @return: 0 in case of success.
+ *       -1 in other case.
+ */
+static int
+tpm_st33_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+        u32 err;
+        u8 intmask;
+        struct tpm_chip *chip;
+        struct st33zp24_platform_data *platform_data;
+
+        err = 0;
+
+        if (client == NULL) {
+                dev_info(&client->dev, "client is NULL. exiting.\n");
+                err = -ENODEV;
+                goto end;
+        }
+
+        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+                dev_info(&client->dev, "client not i2c capable\n");
+                err = -ENODEV;
+                goto end;
+        }
+
+        chip = tpm_register_hardware(&client->dev, &st_i2c_tpm);
+        if (!chip) {
+                dev_info(&client->dev, "fail chip\n");
+                err = -ENODEV;
+                goto end;
+        }
+
+        platform_data = client->dev.platform_data;
+        platform_data->tpm_i2c_buffer[0] =
+            kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
+        if (platform_data->tpm_i2c_buffer[0] == NULL) {
+                err = -ENOMEM;
+                goto _tpm_clean_answer;
+        }
+        platform_data->tpm_i2c_buffer[1] =
+            kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
+        if (platform_data->tpm_i2c_buffer[1] == NULL) {
+                err = -ENOMEM;
+                goto _tpm_clean_response;
+        }
+
+        chip->vendor.iobase = client;
+
+        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);
+
+        chip->vendor.locality = LOCALITY0;
+
+        if (power_mgt) {
+                err = gpio_request(platform_data->io_lpcpd, "TPM IO_LPCPD");
+                if (err)
+                        goto _gpio_init1;
+                gpio_set_value(platform_data->io_lpcpd, 1);
+        }
+
+        if (interrupts) {
+                init_completion(&platform_data->irq_detection);
+                if (request_locality(chip) != LOCALITY0) {
+                        err = -ENODEV;
+                        goto _tpm_clean_response;
+                }
+                err = gpio_request(platform_data->io_serirq, "TPM IO_SERIRQ");
+                if (err)
+                        goto _gpio_init2;
+
+                clear_interruption(client);
+                err = request_irq(gpio_to_irq(platform_data->io_serirq),
+                                &tpm_ioserirq_handler,
+                                IRQF_TRIGGER_HIGH,
+                                "TPM SERIRQ management", chip);
+                if (err < 0) {
+                        dev_err(chip->dev , "TPM SERIRQ signals %d not available\n",
+                        gpio_to_irq(platform_data->io_serirq));
+                        goto _irq_set;
+                }
+
+                err = I2C_READ_DATA(client, TPM_INT_ENABLE, &intmask, 1);
+                if (err < 0)
+                        goto _irq_set;
+
+                intmask |= TPM_INTF_CMD_READY_INT
+                        |  TPM_INTF_FIFO_AVALAIBLE_INT
+                        |  TPM_INTF_WAKE_UP_READY_INT
+                        |  TPM_INTF_LOCALITY_CHANGE_INT
+                        |  TPM_INTF_STS_VALID_INT
+                        |  TPM_INTF_DATA_AVAIL_INT;
+
+                err = I2C_WRITE_DATA(client, TPM_INT_ENABLE, &intmask, 1);
+                if (err < 0)
+                        goto _irq_set;
+
+                intmask = TPM_GLOBAL_INT_ENABLE;
+                err = I2C_WRITE_DATA(client, (TPM_INT_ENABLE + 3), &intmask, 1);
+                if (err < 0)
+                        goto _irq_set;
+
+                err = I2C_READ_DATA(client, TPM_INT_STATUS, &intmask, 1);
+                if (err < 0)
+                        goto _irq_set;
+
+                chip->vendor.irq = interrupts;
+
+                tpm_gen_interrupt(chip);
+        }
+
+        tpm_get_timeouts(chip);
+
+        i2c_set_clientdata(client, chip);
+        platform_data->bChipF = false;
+
+        dev_info(chip->dev, "TPM I2C Initialized\n");
+        return 0;
+_irq_set:
+        free_irq(gpio_to_irq(platform_data->io_serirq), (void *) chip);
+_gpio_init2:
+        if (platform_data && interrupts)
+                gpio_free(platform_data->io_serirq);
+_gpio_init1:
+        if (platform_data && power_mgt)
+                gpio_free(platform_data->io_lpcpd);
+_tpm_clean_response:
+        tpm_remove_hardware(chip->dev);
+        if (platform_data->tpm_i2c_buffer[1] != NULL) {
+                kzfree(platform_data->tpm_i2c_buffer[1]);
+                platform_data->tpm_i2c_buffer[1] = NULL;
+        }
+_tpm_clean_answer:
+        if (platform_data->tpm_i2c_buffer[0] != NULL) {
+                kzfree(platform_data->tpm_i2c_buffer[0]);
+                platform_data->tpm_i2c_buffer[0] = NULL;
+        }
+
+        platform_data->bChipF = true;
+end:
+        pr_info("TPM I2C initialisation fail\n");
+        return err;
+}
+
+/*
+ * tpm_st33_i2c_remove remove the TPM device
+ * @param: client, the i2c_client drescription (TPM I2C description).
+                clear_bit(0, &chip->is_open);
+ * @return: 0 in case of success.
+ */
+static __devexit int tpm_st33_i2c_remove(struct i2c_client *client)
+{
+        struct tpm_chip *chip = (struct tpm_chip *)i2c_get_clientdata(client);
+        struct st33zp24_platform_data *pin_infos =
+                ((struct i2c_client *) chip->vendor.iobase)->dev.platform_data;
+
+        if (pin_infos != NULL) {
+                free_irq(pin_infos->io_serirq, chip);
+
+                gpio_free(pin_infos->io_serirq);
+                gpio_free(pin_infos->io_lpcpd);
+
+                if (pin_infos->bChipF != true)
+                        tpm_remove_hardware(chip->dev);
+                if (pin_infos->tpm_i2c_buffer[1] != NULL) {
+                        kzfree(pin_infos->tpm_i2c_buffer[1]);
+                        pin_infos->tpm_i2c_buffer[1] = NULL;
+                }
+                if (pin_infos->tpm_i2c_buffer[0] != NULL) {
+                        kzfree(pin_infos->tpm_i2c_buffer[0]);
+                        pin_infos->tpm_i2c_buffer[0] = NULL;
+                }
+        }
+
+        return 0;
+}
+
+/*
+ * tpm_st33_i2c_pm_suspend suspend the TPM device
+ * Added: Work around when suspend and no tpm application is running, suspend
+ * may fail because chip->data_buffer is not set (only set in tpm_open in Linux
+ * TPM core)
+ * @param: client, the i2c_client drescription (TPM I2C description).
+ * @param: mesg, the power management message.
+ * @return: 0 in case of success.
+ */
+static int tpm_st33_i2c_pm_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+        struct tpm_chip *chip =
+            (struct tpm_chip *)i2c_get_clientdata(client);
+        struct st33zp24_platform_data *pin_infos =
+                ((struct i2c_client *)chip->vendor.iobase)->dev.platform_data;
+        int ret = 0;
+
+        if (power_mgt)
+                gpio_set_value(pin_infos->io_lpcpd, 0);
+        else{
+                if (chip->data_buffer == NULL)
+                        chip->data_buffer = pin_infos->tpm_i2c_buffer[0];
+                ret = tpm_pm_suspend(&client->dev);
+        }
+        return ret;
+}                               /* tpm_st33_i2c_suspend() */
+
+/*
+ * tpm_st33_i2c_pm_resume resume the TPM device
+ * @param: client, the i2c_client drescription (TPM I2C description).
+ * @return: 0 in case of success.
+ */
+static int tpm_st33_i2c_pm_resume(struct i2c_client *client)
+{
+        struct tpm_chip *chip =
+            (struct tpm_chip *)i2c_get_clientdata(client);
+        struct st33zp24_platform_data *pin_infos =
+                ((struct i2c_client *)chip->vendor.iobase)->dev.platform_data;
+
+        int ret = 0;
+
+        if (power_mgt) {
+                gpio_set_value(pin_infos->io_lpcpd, 1);
+                ret = wait_for_serirq_timeout(chip,
+                                          (chip->vendor.status(chip) &&
+                                          TPM_STS_VALID) == TPM_STS_VALID,
+                                          chip->vendor.timeout_b);
+        } else{
+        if (chip->data_buffer == NULL)
+                chip->data_buffer = pin_infos->tpm_i2c_buffer[0];
+        ret = tpm_pm_resume(&client->dev);
+        if (!ret)
+                tpm_do_selftest(chip);
+        }
+        return ret;
+}                               /* tpm_st33_i2c_pm_resume() */
+
+static const struct i2c_device_id tpm_st33_i2c_id[] = {
+        {TPM_ST33_I2C, 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(i2c, tpm_st33_i2c_id);
+
+static struct i2c_driver tpm_st33_i2c_driver = {
+        .driver = {
+                   .owner = THIS_MODULE,
+                   .name = TPM_ST33_I2C,
+                   },
+        .probe = tpm_st33_i2c_probe,
+        .remove = tpm_st33_i2c_remove,
+        .resume = tpm_st33_i2c_pm_resume,
+        .suspend = tpm_st33_i2c_pm_suspend,
+        .id_table = tpm_st33_i2c_id
+};
+
+/*
+ * tpm_st33_i2c_init initialize driver
+ * @return: 0 if successful, else non zero value.
+ */
+static int __init tpm_st33_i2c_init(void)
+{
+        return i2c_add_driver(&tpm_st33_i2c_driver);
+}
+
+/*
+ * tpm_st33_i2c_exit The kernel calls this function during unloading the
+ * module or during shut down process
+ */
+static void __exit tpm_st33_i2c_exit(void)
+{
+        i2c_del_driver(&tpm_st33_i2c_driver);
+}
+
+module_init(tpm_st33_i2c_init);
+module_exit(tpm_st33_i2c_exit);
+
+MODULE_AUTHOR("Christophe Ricard (tpmsupport@st.com)");
+MODULE_DESCRIPTION("STM TPM I2C ST33 Driver");
+MODULE_VERSION("1.2.0");
diff --git a/drivers/char/tpm/tpm_stm_st33_i2c.h b/drivers/char/tpm/tpm_stm_st33_i2c.h
new file mode 100644
index 000000000000..d390542db869
--- /dev/null
+++ b/drivers/char/tpm/tpm_stm_st33_i2c.h
@@ -0,0 +1,81 @@
+/*
+ * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
+ * Copyright (C) 2009, 2010  STMicroelectronics
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * STMicroelectronics version 1.2.0, Copyright (C) 2010
+ * STMicroelectronics comes with ABSOLUTELY NO WARRANTY.
+ * This is free software, and you are welcome to redistribute it
+ * under certain conditions.
+ *
+ * @Author: Christophe RICARD tpmsupport@st.com
+ *
+ * @File: stm_st33_tpm_i2c.h
+ *
+ * @Date: 09/15/2010
+ */
+#ifndef __STM_ST33_TPM_I2C_MAIN_H__
+#define __STM_ST33_TPM_I2C_MAIN_H__
+
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+#include <linux/gpio.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+
+#include "tpm.h"
+
+#define MINOR_NUM_I2C           224
+
+#define TPM_ACCESS                      (0x0)
+#define TPM_STS                         (0x18)
+#define TPM_HASH_END                    (0x20)
+#define TPM_DATA_FIFO                   (0x24)
+#define TPM_HASH_DATA                   (0x24)
+#define TPM_HASH_START                  (0x28)
+#define TPM_INTF_CAPABILITY             (0x14)
+#define TPM_INT_STATUS                  (0x10)
+#define TPM_INT_ENABLE                  (0x08)
+
+#define TPM_DUMMY_BYTE                  0xAA
+#define TPM_WRITE_DIRECTION             0x80
+#define TPM_HEADER_SIZE                 10
+#define TPM_BUFSIZE                     2048
+
+#define LOCALITY0               0
+
+struct st_tpm_hash {
+        int size;
+        u8 *data;
+};
+
+#endif /* __STM_ST33_TPM_I2C_MAIN_H__ */