This driver add support to STMicroelectronics ST33ZP24 SPI TPM.
Signed-off-by: Jean-Luc BLANC <jean-luc.bl...@st.com>
---
README | 12 +
drivers/tpm/Makefile | 1 +
drivers/tpm/tpm_spi_stm_st33.c | 671 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 684 insertions(+)
create mode 100644 drivers/tpm/tpm_spi_stm_st33.c
diff --git a/README b/README
index aea82be..e04866d 100644
--- a/README
+++ b/README
@@ -1322,6 +1322,18 @@ The following options need to be configured:
Define this to enable authorized functions in the TPM library.
Requires CONFIG_TPM and CONFIG_SHA1.
+ CONFIG_TPM_ST_SPI
+ Support SPI STMicroelectronics TPM. Require SPI support
+
+ TPM0_SPI_MAX_SPEED
+ Define SPI frequency for TPM, 10000000 Hz max
+
+ TPM0_SPI_BUS_NUM
+ Define SPI Bus ID connected to TPM
+
+ TPM0_SPI_CS
+ Define SPI Chip Select ID connected to TPM
+
- USB Support:
At the moment only the UHCI host controller is
supported (PIP405, MIP405, MPC5200); define
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
index 150570e..1ee707e 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_TPM_TIS_I2C) += tpm.o
obj-$(CONFIG_TPM_TIS_I2C) += tpm_tis_i2c.o
obj-$(CONFIG_TPM_TIS_LPC) += tpm_tis_lpc.o
obj-$(CONFIG_TPM_TIS_SANDBOX) += tpm_tis_sandbox.o
+obj-$(CONFIG_TPM_ST_SPI) += tpm_spi_stm_st33.o
diff --git a/drivers/tpm/tpm_spi_stm_st33.c b/drivers/tpm/tpm_spi_stm_st33.c
new file mode 100644
index 0000000..78a4e54
--- /dev/null
+++ b/drivers/tpm/tpm_spi_stm_st33.c
@@ -0,0 +1,671 @@
+/*
+ * STMicroelectronics TPM SPI UBOOT Linux driver for TPM ST33ZP24
+ * Copyright (C) 2014 STMicroelectronics
+
+ *
+ * Description: Device driver for ST33ZP24 SPI 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 SPI Protocol Stack Specification version 1.2.0.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * @Author: Jean-Luc BLANC <jean-luc.bl...@st.com>
+ *
+ * @File: tpm_spi_stm_st33.c
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <linux/types.h>
+#include <tpm.h>
+#include <errno.h>
+#include <asm/unaligned.h>
+
+#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 0x00
+#define TPM_WRITE_DIRECTION 0x80
+#define TPM_HEADER_SIZE 10
+#define TPM_BUFSIZE 2048
+
+#define LOCALITY0 0
+#define LOCALITY1 1
+#define LOCALITY2 2
+#define LOCALITY3 3
+#define LOCALITY4 4
+
+/* Index of Count field in TPM response buffer */
+#define TPM_RSP_SIZE_BYTE 2
+
+#define MAX_NUMBER_TPM_ONBOARD 2
+
+#define SPI_WRITE_HEADER_SIZE 4
+
+struct tpm_chip {
+ int latency;
+ int is_open;
+ bool bchipf;
+ int locality;
+ u8 buf[TPM_BUFSIZE];
+ unsigned long timeout_a, timeout_b, timeout_c, timeout_d; /* msec */
+ unsigned long duration; /* msec */
+ struct spi_slave *tpm_dev_spi_info;
+};
+
+struct tpm_chip tpm_st33_spi_board_info[1];
+
+struct tpm_chip *active_tpm;
+
+/* Error value returned on various TPM driver errors. */
+#define TPM_DRIVER_ERR (1)
+
+/* Maximum command duration */
+#define TPM_MAX_COMMAND_DURATION 120000
+
+#define min_t(type, x, y) ({ \
+ type __min1 = (x); \
+ type __min2 = (y); \
+ __min1 < __min2 ? __min1 : __min2; })
+
+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 = 0x80,
+ TPM_INTF_FIFO_AVALAIBLE_INT = 0x40,
+ TPM_INTF_WAKE_UP_READY_INT = 0x20,
+ TPM_INTF_LOC4SOFTRELEASE_INT = 0x08,
+ TPM_INTF_LOCALITY_CHANGE_INT = 0x04,
+ TPM_INTF_STS_VALID_INT = 0x02,
+ TPM_INTF_DATA_AVAIL_INT = 0x01,
+};
+
+enum tis_defaults {
+ TIS_SHORT_TIMEOUT = 750, /* ms */
+ TIS_LONG_TIMEOUT = 2000, /* 2 sec */
+};
+
+
+/*
+ * spi_write8_reg
+ * Send byte to the TIS register according to the ST33ZP24 SPI protocol.
+ * @param: tpm, 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: should be zero if success else a negative error code.
+ */
+static int spi_write8_reg(struct tpm_chip *tpm, u8 tpm_register,
+ const u8 *tpm_data, u16 tpm_size)
+{
+ u8 data = 0;
+ int total_length = 0, nbr_dummy_bytes = 0;
+ int value = 0;
+ u8 tx_buffer[TPM_BUFSIZE + SPI_WRITE_HEADER_SIZE];
+
+ data = TPM_WRITE_DIRECTION | tpm->locality;
+ memcpy(tx_buffer + total_length, &data, sizeof(data));
+ total_length++;
+ data = tpm_register;
+ memcpy(tx_buffer + total_length, &data, sizeof(data));
+ total_length++;
+
+ if (tpm_size > 0 && ((tpm_register == TPM_DATA_FIFO)
+ || (tpm_register == TPM_HASH_DATA))) {
+ tx_buffer[total_length++] = tpm_size >> 8;
+ tx_buffer[total_length++] = tpm_size;
+ }
+ memcpy(tx_buffer + total_length, tpm_data, tpm_size);
+ total_length += tpm_size;
+ nbr_dummy_bytes = tpm->latency + 1;
+ memset(tx_buffer + total_length, TPM_DUMMY_BYTE, nbr_dummy_bytes);
+
+ spi_claim_bus(tpm->tpm_dev_spi_info);
+ value = spi_xfer(tpm->tpm_dev_spi_info,
+ (total_length + nbr_dummy_bytes)*8, tx_buffer,
+ tx_buffer, SPI_XFER_BEGIN | SPI_XFER_END);
+ spi_release_bus(tpm->tpm_dev_spi_info);
+
+ return value;
+} /* spi_write8_reg() */
+
+/*
+ * spi_read8_reg
+ * Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
+ * @param: tpm, the chip description
+ * @param: tpm_loc, the locality to read register from
+ * @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: should be zero if success else a negative error code.
+ */
+static u8 spi_read8_reg(struct tpm_chip *tpm, u8 tpm_loc, u8 tpm_register,
+ u8 *tpm_data, u16 tpm_size)
+{
+ u8 data = 0;
+ int total_length = 0, nbr_dummy_bytes;
+ int value = 0;
+ u8 *data_buffer;
+
+ data_buffer = tpm_data;
+ /* SPI read message is : locality & direction */
+ data = tpm_loc;
+ memcpy(data_buffer + total_length, &data, sizeof(data));
+ total_length++;
+ /* + TPM target register */
+ data = tpm_register;
+ memcpy(data_buffer + total_length, &data, sizeof(data));
+ total_length++;
+ /* + TPM latency (2B) + Status byte (1B) + Nb to read (tpm_size) */
+ nbr_dummy_bytes = tpm->latency + 1 + tpm_size;
+ memset(&data_buffer[total_length], TPM_DUMMY_BYTE, nbr_dummy_bytes);
+
+ spi_claim_bus(tpm->tpm_dev_spi_info);
+ value = spi_xfer(tpm->tpm_dev_spi_info,
+ (total_length + nbr_dummy_bytes)*8,
+ data_buffer, tpm_data, SPI_XFER_BEGIN | SPI_XFER_END);
+ spi_release_bus(tpm->tpm_dev_spi_info);
+
+ if (tpm_size > 0 && value == 0) {
+ if (tpm_data[tpm->latency + 2] == 0x5A)
+ memcpy(tpm_data,
+ tpm_data + total_length + nbr_dummy_bytes - tpm_size,
+ tpm_size);
+ else {
+ printf("Error in the TPM command, TPM status byte = ");
+ printf("%x\n", tpm_data[tpm->latency + tpm_size + 1]);
+ value = -TPM_DRIVER_ERR;
+ }
+ }
+ return value;
+} /* spi_read8_reg() */
+
+/*
+ * tpm_stm_spi_cancel_or_command_ready, cancel command or move TPM in
+ * Command Ready state
+ * @param: chip, the tpm chip description as specified in
+ * driver/char/tpm/tpm.h.
+ */
+static void tpm_stm_spi_cancel_or_command_ready(struct tpm_chip *chip)
+{
+ u8 data = TPM_STS_COMMAND_READY;
+
+ spi_write8_reg(chip, TPM_STS, &data, 1);
+} /* tpm_stm_spi_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_spi_status(struct tpm_chip *chip)
+{
+ spi_read8_reg(chip, active_tpm->locality, TPM_STS, active_tpm->buf, 1);
+ return active_tpm->buf[0];
+} /* tpm_stm_spi_status() */
+
+/*
+ * check_locality if the locality is active
+ * @param: chip, the tpm chip description
+ * @return: the active locality or -1 if no locality active.
+ */
+static int check_locality(struct tpm_chip *chip)
+{
+ u8 status;
+ int ret, loc_to_check = 0;
+
+ do {
+ status = spi_read8_reg(chip, loc_to_check, TPM_ACCESS,
+ active_tpm->buf, 1);
+ if ((status == 0) && (active_tpm->buf[0] &
+ (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+ (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
+ break;
+ loc_to_check++;
+ } while (loc_to_check < 5);
+ if (loc_to_check == 5)
+ ret = -TPM_DRIVER_ERR;
+ else
+ ret = loc_to_check;
+ return ret;
+} /* 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;
+ int rc;
+ u8 data = 0;
+
+ /* Check locality */
+ if (check_locality(chip) == chip->locality)
+ return chip->locality;
+
+ /* Request locality */
+ data = TPM_ACCESS_REQUEST_USE;
+ rc = spi_write8_reg(chip, 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) == chip->locality)
+ return chip->locality;
+ } while (get_timer(start) < stop);
+ rc = -TPM_DRIVER_ERR;
+end:
+ return rc;
+} /* request_locality() */
+
+/*
+ * release_locality release the active locality
+ * @param: chip, the tpm chip description.
+ * @return: should be zero if success else a negative error code.
+ */
+static int release_locality(struct tpm_chip *chip)
+{
+ u8 data = 0;
+
+ data = TPM_ACCESS_ACTIVE_LOCALITY;
+ return spi_write8_reg(chip, TPM_ACCESS, &data, 1);
+} /* release_locality()*/
+
+/*
+ * 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 start, stop;
+ u32 burstcnt;
+ u8 tpm_reg;
+ long status = 0;
+ int ret;
+
+ /* wait for burstcount */
+ start = get_timer(0);
+ stop = chip->timeout_d;
+ do {
+ tpm_reg = TPM_STS + 1;
+ status = spi_read8_reg(chip, active_tpm->locality, tpm_reg,
+ active_tpm->buf, 1);
+ if (status < 0)
+ return -EBUSY;
+
+ burstcnt = active_tpm->buf[0];
+ status = spi_read8_reg(chip, active_tpm->locality, ++tpm_reg,
+ active_tpm->buf, 1);
+ if (status < 0)
+ return -EBUSY;
+
+ burstcnt |= active_tpm->buf[0] << 8;
+ if (burstcnt) {
+ ret = burstcnt;
+ goto end;
+ }
+ } while (get_timer(start) < stop);
+ ret = -TPM_DRIVER_ERR;
+end:
+ return ret;
+} /* 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: 0 if success, -ETIME if timeout is reached.
+ */
+static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout)
+{
+ unsigned long start, stop;
+ u8 status;
+
+ /* check current status */
+ status = tpm_stm_spi_status(chip);
+ if ((status & mask) == mask)
+ return 0;
+
+ start = get_timer(0);
+ stop = chip->timeout_d;
+ do {
+ status = tpm_stm_spi_status(chip);
+ if ((status & mask) == mask)
+ return 0;
+ } while (get_timer(start) < 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: number of byte read on success, minus error code otherwise.
+ */
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+ int size = 0, burstcnt, len;
+ long status = 0;
+
+ while (size < count &&
+ wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ chip->timeout_c) == 0) {
+ burstcnt = get_burstcount(chip);
+ len = min_t(int, burstcnt, count - size);
+ status = spi_read8_reg(chip, active_tpm->locality,
+ TPM_DATA_FIFO, buf + size, len);
+ if (status < 0)
+ return status;
+ size += len;
+ }
+return size;
+} /* recv_data() */
+
+
+/*
+ * tpm_stm_spi_send send TPM commands through the SPI bus.
+ * @param: chip, the tpm chip description
+ * @param: buf, the tpm command buffer
+ * @param: len, the tpm command size
+ * @return: 0 if success else the negative error code.
+ */
+static int tpm_stm_spi_send(struct tpm_chip *chip, const unsigned char *buf,
+ size_t len)
+{
+ u32 burstcnt = 0, i, size = 0;
+ u8 data = 0;
+ long status = 0, ret = 0;
+
+ if (chip == NULL)
+ return -EINVAL;
+ if (len < TPM_HEADER_SIZE)
+ return -EINVAL;
+
+ ret = request_locality(chip);
+ if (ret < 0)
+ return ret;
+
+ status = tpm_stm_spi_status(chip);
+ if ((status & TPM_STS_COMMAND_READY) == 0) {
+ tpm_stm_spi_cancel_or_command_ready(chip);
+ if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
+ chip->timeout_b) < 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 = spi_write8_reg(chip, TPM_DATA_FIFO, buf, size);
+ if (ret < 0)
+ goto out_err;
+ i += size;
+ }
+
+ status = tpm_stm_spi_status(chip);
+ if ((status & TPM_STS_DATA_EXPECT) == 0) {
+ ret = -EIO;
+ goto out_err;
+ }
+
+ /* write last byte */
+ spi_write8_reg(chip, TPM_DATA_FIFO, buf + len - 1, 1);
+
+ status = tpm_stm_spi_status(chip);
+ if ((status & TPM_STS_DATA_EXPECT) != 0) {
+ ret = -EIO;
+ goto out_err;
+ }
+
+ /* go and do it */
+ data = TPM_STS_GO;
+ ret = spi_write8_reg(chip, TPM_STS, &data, 1);
+ if (ret < 0)
+ goto out_err;
+
+ return len;
+out_err:
+ tpm_stm_spi_cancel_or_command_ready(chip);
+ release_locality(chip);
+ return ret;
+}
+
+/*
+ * tpm_stm_spi_send_hash send TPM locality 4 hash datas through the SPI 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: 0 in case of success else the negative error code.
+ */
+static int tpm_stm_spi_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->locality = LOCALITY4;
+ if (request_locality(chip) != LOCALITY4) {
+ printf("Failed to select locality 4, hash abort\n");
+ return -TPM_DRIVER_ERR;
+ }
+
+ data = TPM_DUMMY_BYTE;
+ ret = spi_write8_reg(chip, TPM_HASH_START, &data, 1);
+ if (ret != 0)
+ goto end;
+ ret = spi_write8_reg(chip, TPM_DATA_FIFO, buf, len);
+ if (ret != 0)
+ goto end;
+ ret = spi_write8_reg(chip, TPM_HASH_END, &data, 1);
+ if (ret != 0)
+ goto end;
+
+end:
+ release_locality(chip);
+ chip->locality = LOCALITY0;
+ ret |= request_locality(chip);
+ return ret;
+} /* tpm_stm_spi_send_hash */
+
+
+/*
+ * tpm_stm_spi_recv received TPM response through the SPI bus.
+ * @param: chip, the tpm chip description
+ * @param: buf, the tpm command buffer
+ * @param: len, the tpm command size
+* @return: 0 if success else the negative error code.
+ */
+static int tpm_stm_spi_recv(struct tpm_chip *chip, unsigned char *buf,
+ size_t count)
+{
+ int size = 0;
+ int expected;
+ u8 rx_buffer[TPM_BUFSIZE];
+
+ if (chip == NULL)
+ return -EINVAL;
+ if (count < TPM_HEADER_SIZE) {
+ size = -EIO;
+ goto out;
+ }
+
+ size = recv_data(chip, buf, TPM_HEADER_SIZE);
+
+ /* read first 10 bytes, including tag, paramsize, and result */
+ if (size < TPM_HEADER_SIZE) {
+ printf("TPM error, unable to read header\n");
+ goto out;
+ }
+ memcpy(rx_buffer, buf, TPM_HEADER_SIZE);
+ expected = get_unaligned_be32(rx_buffer + TPM_RSP_SIZE_BYTE);
+ if (expected > count) {
+ size = -EIO;
+ goto out;
+ }
+
+ size += recv_data(chip, buf, expected - TPM_HEADER_SIZE);
+ if (size < expected) {
+ printf("TPM error, unable to read remaining bytes of result\n");
+ size = -ETIME;
+ goto out;
+ }
+ memcpy(rx_buffer+TPM_HEADER_SIZE, buf, expected - TPM_HEADER_SIZE);
+ memcpy(buf, rx_buffer, expected);
+out:
+ tpm_stm_spi_cancel_or_command_ready(chip);
+ release_locality(chip);
+ return size;
+}
+
+/*
+ * tis_init() setup the SPI bus and check TPM(s) presence on it
+ * @return: 0 on success (the device is found or was found during an earlier
+ * invocation) or -ENODEV if the device is not found.
+ * Upon exit, TPM0 is the one active if present.
+ */
+int tis_init(void)
+{
+ int rc = 0;
+ struct spi_slave *slave;
+
+ slave = spi_setup_slave(TPM0_SPI_BUS_NUM, TPM0_SPI_CS,
+ TPM0_SPI_MAX_SPEED, SPI_MODE_0);
+ if (slave != NULL) {
+ active_tpm = &tpm_st33_spi_board_info[0];
+ active_tpm->timeout_a = TIS_SHORT_TIMEOUT;
+ active_tpm->timeout_b = TIS_LONG_TIMEOUT;
+ active_tpm->timeout_c = TIS_SHORT_TIMEOUT;
+ active_tpm->timeout_d = TIS_SHORT_TIMEOUT;
+ active_tpm->locality = LOCALITY0;
+ active_tpm->duration = TPM_MAX_COMMAND_DURATION;
+ active_tpm->tpm_dev_spi_info = slave;
+ active_tpm->latency = 2;
+ if (spi_read8_reg(active_tpm, active_tpm->locality,
+ TPM_ACCESS, active_tpm->buf, 1) != 0) {
+ rc = -TPM_DRIVER_ERR;
+ active_tpm->is_open = 0;
+ goto out_err;
+ }
+ active_tpm->is_open = 1;
+ printf("ST33ZP24 SPI TPM from STMicroelectronics found\n");
+ }
+out_err:
+ return rc;
+} /* tis_init() */
+
+/*
+ * tis_sendrecv() send the requested data to the TPM and then try read 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;
+
+ if (active_tpm->is_open == 0)
+ return -TPM_DRIVER_ERR;
+
+ if (sizeof(active_tpm->buf) < sbuf_size)
+ return -TPM_DRIVER_ERR;
+ len = tpm_stm_spi_send(active_tpm, sendbuf, sbuf_size);
+
+ if (len < sbuf_size) {
+ printf("TPM error, command not fully transmitted");
+ printf(", only %d sent where expect %d\n", len, sbuf_size);
+ return -TPM_DRIVER_ERR;
+ }
+ if (wait_for_stat(active_tpm, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ active_tpm->timeout_c) != 0)
+ return -TPM_DRIVER_ERR;
+
+ len = tpm_stm_spi_recv(active_tpm, active_tpm->buf,
+ sizeof(active_tpm->buf));
+ if (len < 10) {
+ *rbuf_len = 0;
+ return -TPM_DRIVER_ERR;
+ }
+ if (recvbuf != NULL) {
+ memcpy(recvbuf, active_tpm->buf, len);
+ *rbuf_len = len;
+ } else {
+ printf("recvbuf is NULL, drop the TPM answer\n");
+ }
+
+ return 0;
+} /* tis_sendrecv() */
+
+/*
+ * tis_open() requests access to locality 0. After all commands have been
+ * completed the caller is supposed to call tis_close().
+ * @param: chip_number, the tpm chip to activate (0 or 1)
+ * @return: 0 on success, -TPM_DRIVER_ERR if an error occur
+ */
+int tis_open(void)
+{
+ if (tis_close())
+ return -TPM_DRIVER_ERR;
+ /* now request access to locality. */
+ if (request_locality(active_tpm) != 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.
+ * @return: Returns 0 on success or TPM_DRIVER_ERR on failure (in case lock
+ * removal did not succeed).
+ */
+int tis_close(void)
+{
+ return release_locality(active_tpm);
+} /* tis_close() */
+
--
1.7.9.5
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