/*
 * 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/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/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 "tpm.h"
#include "tpm_i2c_stm_st33.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)
{
        struct st33zp24_platform_data *pin_infos;

        pin_infos = client->dev.platform_data;

        pin_infos->tpm_i2c_buffer[0][0] = tpm_register;
        memcpy(&pin_infos->tpm_i2c_buffer[0][1], tpm_data, tpm_size);
        return i2c_master_send(client, pin_infos->tpm_i2c_buffer[0],
                                tpm_size + 1);
} /* 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;

        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 *)TPM_VPRIV(chip);
        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() */

static int wait_for_serirq_timeout(struct tpm_chip *chip, bool condition,
                                 unsigned long timeout)
{
        int status = 2;
        struct i2c_client *client;

        client = (struct i2c_client *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);
        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);

        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 *)TPM_VPRIV(chip);
        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 status, burstcnt = 0, i, size;
        int ret;
        u8 data;
        struct i2c_client *client;

        if (chip == NULL)
                return -EBUSY;
        if (len < TPM_HEADER_SIZE)
                return -EBUSY;

        client = (struct i2c_client *)TPM_VPRIV(chip);

        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;

        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 bool tpm_st33_i2c_req_canceled(struct tpm_chip *chip, u8 status)
{
        return (status == TPM_STS_COMMAND_READY);
}

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_st33_i2c_req_canceled,
        .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)
{
        int err;
        u8 intmask;
        struct tpm_chip *chip;
        struct st33zp24_platform_data *platform_data;

        if (client == NULL) {
                pr_info("%s: i2c client is NULL. Device not accessible.\n",
                        __func__);
                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;

        if (!platform_data) {
                dev_info(&client->dev, "chip not available\n");
                err = -ENODEV;
                goto _tpm_clean_answer;
        }

        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_response1;
        }

        TPM_VPRIV(chip) = 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_response2;
                }
                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);

        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 (interrupts)
                gpio_free(platform_data->io_serirq);
_gpio_init1:
        if (power_mgt)
                gpio_free(platform_data->io_lpcpd);
_tpm_clean_response2:
        kzfree(platform_data->tpm_i2c_buffer[1]);
        platform_data->tpm_i2c_buffer[1] = NULL;
_tpm_clean_response1:
        kzfree(platform_data->tpm_i2c_buffer[0]);
        platform_data->tpm_i2c_buffer[0] = NULL;
_tpm_clean_answer:
        tpm_remove_hardware(chip->dev);
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 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 *)TPM_VPRIV(chip))->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);

                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;
}

#ifdef CONFIG_PM_SLEEP
/*
 * 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 device *dev)
{
        struct tpm_chip *chip = dev_get_drvdata(dev);
        struct st33zp24_platform_data *pin_infos = 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(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 device *dev)
{
        struct tpm_chip *chip = dev_get_drvdata(dev);
        struct st33zp24_platform_data *pin_infos = 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(dev);
                if (!ret)
                        tpm_do_selftest(chip);
        }
        return ret;
}                               /* tpm_st33_i2c_pm_resume() */
#endif

static const struct i2c_device_id tpm_st33_i2c_id[] = {
        {TPM_ST33_I2C, 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, tpm_st33_i2c_id);
static SIMPLE_DEV_PM_OPS(tpm_st33_i2c_ops, tpm_st33_i2c_pm_suspend,
        tpm_st33_i2c_pm_resume);
static struct i2c_driver tpm_st33_i2c_driver = {
        .driver = {
                   .owner = THIS_MODULE,
                   .name = TPM_ST33_I2C,
                   .pm = &tpm_st33_i2c_ops,
                   },
        .probe = tpm_st33_i2c_probe,
        .remove = tpm_st33_i2c_remove,
        .id_table = tpm_st33_i2c_id
};

module_i2c_driver(tpm_st33_i2c_driver);

MODULE_AUTHOR("Christophe Ricard (tpmsupport@st.com)");
MODULE_DESCRIPTION("STM TPM I2C ST33 Driver");
MODULE_VERSION("1.2.0");
MODULE_LICENSE("GPL");