[U-Boot,4/4] i2c: Add ST33ZP24 I2C TPM support

This driver add support to STMicroelectronics ST33ZP24 I2C TPM.

Signed-off-by: Jean-Luc BLANC <jean-luc.blanc@st.com>
---
 README                         |    7 +
 drivers/tpm/tpm_i2c_stm_st33.c |  659 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 666 insertions(+)
 create mode 100644 drivers/tpm/tpm_i2c_stm_st33.c

Hi Jean-Luc,

On 1 April 2014 06:05, Jean-Luc BLANC <stmicroelectronics.tpm@gmail.com>wrote:

> This driver add support to STMicroelectronics ST33ZP24 I2C TPM.
>

See my comments on the SPI driver, some of which apply here.


>
> Signed-off-by: Jean-Luc BLANC <jean-luc.blanc@st.com>
> ---
>  README                         |    7 +
>  drivers/tpm/tpm_i2c_stm_st33.c |  659
> ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 666 insertions(+)
>  create mode 100644 drivers/tpm/tpm_i2c_stm_st33.c
>
> diff --git a/README b/README
> index 56c398a..a1eae3e 100644
> --- a/README
> +++ b/README
> @@ -1351,6 +1351,13 @@ The following options need to be configured:
>                 Support additional hash in locality 4 command for
>                 STMicroelectronics TPMs (SPI or I2C). Require
> CONFIG_CMD_TPM.
>
> +               CONFIG_TPM_ST_I2C
> +               Support I2C STMicroelectronics TPM. Require I2C support
> +
> +                       CONFIG_TPM_I2C_BUS
> +                       Define the i2c bus number for the TPM device
> +
> +
>  - USB Support:
>                 At the moment only the UHCI host controller is
>                 supported (PIP405, MIP405, MPC5200); define
> diff --git a/drivers/tpm/tpm_i2c_stm_st33.c
> b/drivers/tpm/tpm_i2c_stm_st33.c
> new file mode 100644
> index 0000000..ff257af
> --- /dev/null
> +++ b/drivers/tpm/tpm_i2c_stm_st33.c
> @@ -0,0 +1,659 @@
> +/*
> + * STMicroelectronics TPM I2C UBOOT Linux driver for TPM ST33ZP24
> + * Copyright (C) 2014  STMicroelectronics
> +
> + *
> + * Description: Device driver for ST33ZP24 I2C TPM TCG.
> + *
> + * This device driver implements the TPM interface as defined in
> + * the TCG TPM Interface Spec version 1.21, revision 1.0 and the
> + * STMicroelectronics I2C Protocol Stack Specification version 1.2.0.
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + *
> + * @Author: Jean-Luc BLANC <jean-luc.blanc@st.com>
> + *
> + * @File: tpm_i2c_stm_st33.c
> + */
> +
> +#include <common.h>
> +#include <i2c.h>
> +#include <linux/types.h>
> +#include <tpm.h>
> +#include <errno.h>
> +#include <asm/unaligned.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)
>

Haven't you got duplicate defines here? They should go in a private header
file I think.


> +
> +#define TPM_DUMMY_BYTE                 0xAA
> +#define TPM_WRITE_DIRECTION            0x80
> +#define TPM_HEADER_SIZE                        10
> +#define TPM_BUFSIZE                            2048
> +
> +#define LOCALITY0                              0
> +#define LOCALITY4                              4
> +#define LOCALITY0_I2C_ADDR             0x13
> +#define LOCALITY4_I2C_ADDR             0x1B
> +
> +/* Index of Count field in TPM response buffer */
> +#define TPM_RSP_SIZE_BYTE              2
> +
> +/* Error value returned on various TPM driver errors. */
> +#define TPM_DRIVER_ERR                 (1)
> +
> +/* Maximum command duration */
> +#define TPM_MAX_COMMAND_DURATION       120000
> +
> +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_LOCTPM_BUFSIZE4SOFTRELEASE_INT = 0x008,
> +       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,        /* ms */
> +       TIS_LONG_TIMEOUT = 2000,        /* 2 sec */
> +};
> +
> +struct tpm_chip {
> +       uint addr;
> +       uint i2c_bus;
> +       int is_open;
> +       u8 buf[TPM_BUFSIZE];
> +       int locality;
> +       unsigned long timeout_a, timeout_b, timeout_c, timeout_d;  /* msec
> */
> +       unsigned long duration;  /* msec */
> +};
> +
> +static struct tpm_chip tpm_dev;
> +
> +/*
> + * 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 zero in case of success else the negative error code.
> + */
> +static int write8_reg(u8 addr, u8 tpm_register,
> +                    const u8 *tpm_data, u16 tpm_size)
> +{
> +       u8 data;
> +
> +       data = tpm_register;
> +       memcpy(&(tpm_dev.buf[0]), &data, sizeof(data));
> +       memcpy(&(tpm_dev.buf[0])+1, tpm_data, tpm_size);
> +       return i2c_write(addr, 0, 0, &tpm_dev.buf[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: Returns zero in case of success else the negative error code.
> +*/
> +static int read8_reg(u8 addr, u8 tpm_register,
> +u8 *tpm_data, int tpm_size)
> +{
> +       u8 status = 0;
> +       u8 data;
> +
> +       data = TPM_DUMMY_BYTE;
> +       status = write8_reg(addr, tpm_register, &data, 1);
> +       if (status == 0)
> +               status = i2c_read(addr, 0, 0, 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: Returns zero in case of success else the negative error code.
> + */
> +#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: Returns zero in case of success else the negative error code.
> + */
> +#define I2C_READ_DATA(client, tpm_register, tpm_data, tpm_size)\
> +        (read8_reg(client, tpm_register, tpm_data, tpm_size))
> +
> +/*
> + * release_locality release the active locality
> + * @param: chip, the tpm chip description.
> + * @return: Returns zero in case of success else the negative error code.
> + */
> +static int release_locality(struct tpm_chip *chip)
> +{
> +       u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
> +
> +       return I2C_WRITE_DATA(tpm_dev.addr, TPM_ACCESS, &data, 1);
> +} /* release_locality() */
> +
> +
> +/*
> + * check_locality if the locality is active
> + * @param: chip, the tpm chip description
> + * @return: the active locality or -TPM_DRIVER_ERR.
> + */
> +static int check_locality(struct tpm_chip *chip)
> +{
> +       u8 data;
> +       u8 status;
> +
> +       status = I2C_READ_DATA(chip->addr, TPM_ACCESS, &data, 1);
> +       if ((status == 0) && (data &
> +               (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
> +               (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
> +               return chip->locality;
> +       return -TPM_DRIVER_ERR;
> +} /* check_locality() */
> +
> +/*
> + * request_locality request the TPM locality
> + * @param: chip, the chip description
> + * @return: the active locality or -TPM_DRIVER_ERR.
> + */
> +static int request_locality(struct tpm_chip *chip)
> +{
> +       unsigned long start, stop;
> +       long rc;
> +       u8 data;
> +
> +       if (check_locality(chip) == chip->locality)
> +               return chip->locality;
> +
> +       data = TPM_ACCESS_REQUEST_USE;
> +       rc = I2C_WRITE_DATA(chip->addr, TPM_ACCESS, &data, 1);
> +       if (rc < 0)
> +               goto end;
> +
> +       /* wait for locality activated */
> +       start = get_timer(0);
> +       stop = chip->timeout_a;
> +       do {
> +               if (check_locality(chip) >= 0)
> +                       return chip->locality;
> +       } while  (get_timer(start) < stop);
> +       rc = -TPM_DRIVER_ERR;
> +end:
> +       return rc;
> +} /* request_locality() */
> +
> +/*
> + * tpm_stm_spi_status return the TPM_STS register
> + * @param: chip, the tpm chip descriptionc
> + * @return: the TPM_STS register value.
> + */
> +static u8 tpm_stm_i2c_status(struct tpm_chip *chip)
> +{
> +       u8 data;
> +
> +       I2C_READ_DATA(chip->addr, TPM_STS, &data, 1);
> +       return data;
> +} /* tpm_stm_i2c_status() */
> +
> +/*
> + * get_burstcount return the burstcount address 0x19 0x1A
> + * @param: chip, the chip description
> + * return: the burstcount or -TPM_DRIVER_ERR in case of error.
> + */
> +static int get_burstcount(struct tpm_chip *chip)
> +{
> +       unsigned long start, stop;
> +       int burstcnt, status, ret;
> +       u8 tpm_reg, temp;
> +
> +       /* wait for burstcount */
> +       start = get_timer(0);
> +       stop = chip->timeout_d;
> +       do {
> +               tpm_reg = TPM_STS + 1;
> +               status = I2C_READ_DATA(chip->addr, tpm_reg, &temp, 1);
>

Why do you need tpm_reg here?


> +               if (status < 0)
> +                       break;
> +
> +               tpm_reg = tpm_reg + 1;
> +               burstcnt = temp;
> +               status = I2C_READ_DATA(chip->addr, tpm_reg, &temp, 1);
> +               if (status < 0)
> +                       break;
> +
> +               burstcnt |= temp << 8;
> +               if (burstcnt) {
> +                       ret = burstcnt;
> +                       goto end;
> +               }
> +               udelay(TIS_SHORT_TIMEOUT*1000);
> +       } while (get_timer(start) < stop);
> +       ret = -TPM_DRIVER_ERR;
> +end:
> +       return ret;
> +} /* get_burstcount() */
> +
> +/*
> + * tpm_stm_i2c_command_ready, move TPM state to Command Ready state.
> + * @param: chip, tpm_chip description.
> + * return: 0 on success or -TPM_DRIVER_ERR in case of error.
> + */
> +static int tpm_stm_i2c_command_ready(struct tpm_chip *chip)
> +{
> +       unsigned long start, stop;
> +       int ret;
> +       u8 status;
> +       u8 data;
> +
> +       data = TPM_STS_COMMAND_READY;
> +       I2C_WRITE_DATA(chip->addr, TPM_STS, &data, 1);
> +       start = get_timer(0);
> +       stop = tpm_dev.timeout_b;
> +       do {
> +               status = tpm_stm_i2c_status(chip);
> +               printf("status = %d\n", status);
> +               if ((status & data) == data)
> +                       return 0;
> +       } while  (get_timer(start) < stop);
> +       ret = -TPM_DRIVER_ERR;
> +return ret;
> +}      /* tpm_stm_i2c_command_ready() */
> +
> +/*
> + * 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;
> +
> +       while (size < count) {
> +               burstcnt = get_burstcount(chip);
> +               len = count - size;
> +               if ((len) > burstcnt)
> +                       len = burstcnt;
> +       if (
> +       I2C_READ_DATA(chip->addr, TPM_DATA_FIFO, buf + size, len) == 0)
> +                       size += len;
> +               else
> +                       break;
> +       }
> +       return size;
> +} /* recv_data() */
> +
> +/*
> + * tpm_stm_i2c_pool_command_completion pool the TPM_STS register until
> + * command execution complete
> + * @param: chip, the chip description
> + * @return: O when TPM complete command execution or -TPM_DRIVER_ERR.
> + */
> +static int tpm_stm_i2c_pool_command_completion(struct tpm_chip *chip)
> +{
> +       unsigned long start, stop;
> +       long rc;
> +       u8 status;
> +
> +       start = get_timer(0);
> +       stop = tpm_dev.duration;
> +       do {
> +                       status = tpm_stm_i2c_status(chip);
> +                       if ((status & TPM_STS_DATA_AVAIL) ==
> TPM_STS_DATA_AVAIL)
> +                               return 0;
> +               } while  (get_timer(start) < stop);
> +
> +       rc = -TPM_DRIVER_ERR;
> +       return rc;
> +} /* tpm_stm_i2c_pool_command_completion() */
> +
> +/*
> + * tpm_stm_i2c_recv received TPM response through the I2C bus.
> + * @param: chip, tpm_chip description.
> + * @param: buf,        the buffer to store data.
> + * @param: count, the number of bytes that can received (sizeof buf).
> + * @return: Returns zero in case of success else -EIO.
> + */
> +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 -ENODEV;
> +
> +       if (count < TPM_HEADER_SIZE) {
> +               size = -EIO;
> +               goto out;
> +       }
> +       size = recv_data(chip, buf, TPM_HEADER_SIZE);
> +       if (size < TPM_HEADER_SIZE) {
> +               printf("TPM error, unable to read header\n");
> +               goto out;
> +       }
> +       expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
> +       if (expected > count) {
> +               size = -EIO;
> +               goto out;
> +       }
> +       size += recv_data(chip, &buf[TPM_HEADER_SIZE],
> +                                       expected - TPM_HEADER_SIZE);
> +       if (size < expected) {
> +               printf("TPM error, unable to read remaining bytes of
> result\n");
> +               size = -EIO;
> +               goto out;
> +       }
> +
> +out:
> +       tpm_stm_i2c_command_ready(chip);
> +       release_locality(chip);
> +       return size;
> +} /* tpm_stm_i2c_recv() */
> +
> +/*
> + * tpm_stm_i2c_send send TPM commands through the I2C bus.
> + *
> + * @param: chip, tpm_chip description.
> + * @param: buf,        the buffer to send.
> + * @param: len, the number of bytes to send.
> + * @return: Returns zero in case of success else the negative error code.
> + */
> +static int tpm_stm_i2c_send(struct tpm_chip *chip, u8 *buf,
> +                           size_t len)
> +{
> +       u32 ret = 0,
> +       status,
> +       burstcnt = 0, i, size;
> +       u8 data;
> +
> +       if (chip == NULL)
> +               return -ENODEV;
> +       if (len < TPM_HEADER_SIZE)
> +               return -EIO;
> +
> +       ret = request_locality(chip);
> +       if (ret < 0)
> +               return ret;
> +
> +       status = tpm_stm_i2c_status(chip);
> +       if ((status & TPM_STS_COMMAND_READY) == 0)
> +               ret = tpm_stm_i2c_command_ready(chip);
> +       if (ret < 0)
> +               goto out_err;
> +       for (i = 0; i < len - 1;) {
> +               burstcnt = get_burstcount(chip);
> +               size = len - i - 1;
> +               if ((size) > burstcnt)
> +                       size = burstcnt;
> +               ret = I2C_WRITE_DATA(chip->addr, 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(chip->addr, 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;
> +       ret = I2C_WRITE_DATA(chip->addr, TPM_STS, &data, 1);
> +       if (ret < 0)
> +               goto out_err;
> +       return len;
> +
> +out_err:
> +       ret = tpm_stm_i2c_command_ready(chip);
> +       release_locality(chip);
> +       return ret;
> +} /* tpm_stm_i2c_send() */
> +
> +/*
> + * tpm_stm_i2c_send_hash send TPM locality 4 hash datas through the I2C
> bus
> + * to update the PCR[17].
> + * @param: chip, the tpm_chip description.
> + * @param: buf,        the data buffer to send.
> + * @param: len, the number of bytes to send.
> + * @return: Returns zero in case of success else the negative error code.
> + */
> +static int tpm_stm_i2c_send_hash(struct tpm_chip *chip, const uint8_t
> *buf,
> +                           size_t len)
> +{
> +       int ret = 0;
> +       u8 data;
> +
> +       if (chip == NULL)
> +               return -EBUSY;
> +
> +       release_locality(chip);
> +       chip->addr = LOCALITY4_I2C_ADDR;
> +       chip->locality = LOCALITY4;
> +       data = TPM_DUMMY_BYTE;
> +       ret = I2C_WRITE_DATA(chip->addr, TPM_HASH_START, &data, 1);
> +       if (ret != 0)
> +               goto end;
> +       ret = I2C_WRITE_DATA(chip->addr, TPM_DATA_FIFO, buf, len);
> +       if (ret != 0)
> +               goto end;
> +       ret = I2C_WRITE_DATA(chip->addr, TPM_HASH_END, &data, 1);
> +       if (ret != 0)
> +               goto end;
> +
> +end:
> +       release_locality(chip);
> +       chip->locality = LOCALITY0;
> +       chip->addr = LOCALITY0_I2C_ADDR;
> +       ret |= request_locality(chip);
> +       return ret;
> +} /* tpm_stm_i2c_send_hash */
> +
> +/*
> + * tpm_vendor_init initialize the TPM device
> + * @param: dev_addr, the i2c address of the tpm.
> + * @return: 0 in case of success, -ENODEV or TPM_DRIVER_ERR in case of
> error
> + */
> +int tpm_vendor_init(uint32_t dev_addr, uint32_t dev_bus)
> +{
> +       int rc = 0;
> +
> +       tpm_dev.addr = dev_addr;
> +       tpm_dev.i2c_bus = dev_bus;
> +       if (i2c_set_bus_num(tpm_dev.i2c_bus) != 0) {
> +               rc = -ENODEV;
> +               goto out_err;
> +       }
> +
> +       /* Default timeouts */
> +       tpm_dev.timeout_a = TIS_SHORT_TIMEOUT;
> +       tpm_dev.timeout_b = TIS_LONG_TIMEOUT;
> +       tpm_dev.timeout_c = TIS_SHORT_TIMEOUT;
> +       tpm_dev.timeout_d = TIS_SHORT_TIMEOUT;
> +
> +       tpm_dev.locality = LOCALITY0;
> +
> +       tpm_dev.duration = TPM_MAX_COMMAND_DURATION;
> +
> +       if (request_locality(&tpm_dev) != 0) {
> +               rc = -TPM_DRIVER_ERR;
> +               goto out_err;
> +       }
> +
> +       tpm_dev.is_open = 1;
> +       printf("ST33ZP24 I2C TPM from STMicroelectronics found\n");
> +       return 0;
> +
> +out_err:
> +       tpm_dev.is_open = 0;
> +       return rc;
> +} /* tpm_vendor_init() */
> +
> +
> +/*
> + * tis_init() verify presence of ST33ZP24 I2C TPM device and configure
> driver
> + * for it.
> + * @return: 0 on success (the device is found or was found during an
> earlier
> + * invocation) or -ENODEV if the device is not found.
> + */
> +int tis_init(void)
> +{
> +       int rc;
> +       uint32_t dev_addr, dev_bus;
> +
> +       dev_addr = LOCALITY0_I2C_ADDR;
> +       dev_bus = CONFIG_TPM_I2C_BUS;
> +
> +       rc = tpm_vendor_init(dev_addr, dev_bus);
> +       return rc;
> +}      /* tis_init() */
> +
> +/*
> + * tis_sendrecv() send the requested data to the TPM and then try to get
> + * its response
> + * @param: sendbuf - buffer of the data to send
> + * @param: send_size size of the data to send
> + * @param: recvbuf - memory to save the response to
> + * @param: recv_len - pointer to the size of the response buffer
> + *
> + * @return: 0 on success (and places the number of response bytes at
> recv_len)
> + * or -TPM_DRIVER_ERR on failure.
> + */
> +int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
> +               uint8_t *recvbuf, size_t *rbuf_len)
> +{
> +       int len, i;
> +       uint8_t buf[TPM_BUFSIZE];
> +
> +       if (tpm_dev.is_open == 0)
> +               return -TPM_DRIVER_ERR;
> +
> +       if (sizeof(buf) < sbuf_size)
> +               return -TPM_DRIVER_ERR;
> +
> +       memcpy(buf, sendbuf, sbuf_size);
> +       len = tpm_stm_i2c_send(&tpm_dev, buf, sbuf_size);
> +       if (len != sbuf_size) {
> +               printf(" TPM  error, command not fully transmitted\n");
> +               return -TPM_DRIVER_ERR;
> +       }
> +
> +       if (tpm_stm_i2c_pool_command_completion(&tpm_dev) != 0)
> +               return -TPM_DRIVER_ERR;
> +
> +       len = tpm_stm_i2c_recv(&tpm_dev, buf, sizeof(buf));
> +       if (len < 10) {
> +               *rbuf_len = 0;
> +               return -TPM_DRIVER_ERR;
> +       }
> +
> +       memcpy(recvbuf, buf, len);
> +       *rbuf_len = len;
> +       return 0;
> +}      /* tis_sendrecv() */
> +
> +/*
> + * tis_sendhashloc4() perform a hash in locality 4 in order to extend
> PCR17
> + * @param: sendbuf - buffer of the data to send
> + * @param: send_size size of the data to send
> + *
> + * @return: 0 on success or -TPM_DRIVER_ERR on failure.
> + */
> +int tis_sendhashloc4(const uint8_t *sendbuf, size_t sbuf_size)
> +{
> +       int ret;
> +
> +       if (tpm_dev.is_open == 0) {
> +               printf("TPM not yet initialized, perform \"tpm init\"
> first\n");
> +               return -TPM_DRIVER_ERR;
> +       }
> +       ret = tpm_stm_i2c_send_hash(&tpm_dev, sendbuf, sbuf_size);
> +       return ret;
> +}      /* tis_sendhashloc4() */
> +
> +/*
> + * tis_open() requests access to locality 0 for the caller. After all
> + * commands have beencompleted the caller is supposed to call tis_close().
> + *
> + * @return: 0 on success, -TPM_DRIVER_ERR on failure.
> + */
> +int tis_open(void)
> +{
> +       if (tis_close())
> +               return -TPM_DRIVER_ERR;
> +
> +       /* now request access to locality. */
> +       if (request_locality(&tpm_dev) != 0) {
> +               printf("%s:%d - failed to lock locality 0\n",
> +                      __FILE__, __LINE__);
> +               return -TPM_DRIVER_ERR;
> +       }
> +       return 0;
> +}              /* tis_open() */
> +
> +/*
> + * tis_close() terminate the current session with the TPM by releasing
> + * the locked locality. Returns 0 on success or TPM_DRIVER_ERR on failure
> + * (in case lock removal did not succeed).
> + */
> +int tis_close(void)
> +{
> +       int ret;
> +
> +       ret = release_locality(&tpm_dev);
> +       return ret;
> +}      /* tis_close() */
> --
> 1.7.9.5
>
>
Regards,
Simon