Hi Jean-Luc,
On 1 April 2014 06:05, Jean-Luc BLANC <stmicroelectronics....@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.bl...@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.bl...@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
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