Hi Jean-Luc, On 1 April 2014 05:48, Jean-Luc BLANC <stmicroelectronics....@gmail.com>wrote:
> 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 > + > Missing * > + * > + * 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) > We shouldn't need brackets around these constants here, and below. > + > +#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 { > Extra space. > + 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; > Can we have comments on these fields? You can do something like this above the struct: /** * @latency: Some description ... +}; > + > +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) > I think it would be better to use -EIO or something like that from errno.h, rather than creating your own error. > + > +/* Maximum command duration */ > +#define TPM_MAX_COMMAND_DURATION 120000 > Perhaps an _MS suffix to indicate the units are ms? > + > +#define min_t(type, x, y) ({ \ > + type __min1 = (x); \ > + type __min2 = (y); \ > + __min1 < __min2 ? __min1 : __min2; }) > Can we use min()? > + > +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 */ > Again _MS suffix might be nice. > +}; > + > + > +/* > + * spi_write8_reg > + * Send byte to the TIS register according to the ST33ZP24 SPI protocol. > I think it is supposed to be: /** * spi_write8_reg() - Send byte to the TIS register according to the ST33ZP24 SPI protocol. * * Some extra description if you want it. * * @tpm: description * @tpm_register: etc... ... */ Granted, I myself used your style for quite a while, but I believe the new standard for U-Boot is Docbook rather than doxygen. Marek is the expert on this. > + * @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)); > sizeof(data) is 1, so why not just: tx_buffer[total_length++] = tpm_register; in these cases? > + 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); > Error check > + 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; > I think ret would be a better name than value, but it's up to you. > +} /* spi_write8_reg() */ > Don't need this comment. > + > +/* > + * 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); > Should line up with tpm->latency above, not with the memcpy(). Did you use 'patman' to prepare the patches? It should warn about this sort of thing. > + 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); > I think 5 should be an enum / define. > + 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; > -ETIMEDOUT ? > +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 timeoutH > This parameter doesn't seem to be used. > + * @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); > What is happening here with ret? It looks like it can be an error (in which case |= seems dodgy)? > + 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) { > Perhaps: if (!slave) return -ENOENT; > + 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; > Is this assignment needed? Maybe just do return -EIO? > + 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"); > Not nice to printf() in drivers - should you return -EINVAL in this case? or debug()? > + } > + > + 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__); > debug() > + 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 > > Regards, Simon
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