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Diffstat (limited to 'hal_io_i2c.c')
| -rw-r--r-- | hal_io_i2c.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/hal_io_i2c.c b/hal_io_i2c.c new file mode 100644 index 0000000..f521e73 --- /dev/null +++ b/hal_io_i2c.c @@ -0,0 +1,339 @@ +/* + * hal_io_i2c.c + * ------------ + * This module contains common code to talk to the FPGA over the I2C bus. + * + * Author: Paul Selkirk + * Copyright (c) 2014-2015, NORDUnet A/S All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * - Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * - Neither the name of the NORDUnet nor the names of its contributors may + * be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/ioctl.h> +#include <stdint.h> + +#include "cryptech.h" + +#define I2C_dev "/dev/i2c-2" +#define I2C_addr 0x0f +#define I2C_SLAVE 0x0703 + +static int debug = 0; +static int i2cfd = -1; + +/* ---------------- I2C low-level code ---------------- */ + +void hal_io_set_debug(int onoff) +{ + debug = onoff; +} + +static void dump(char *label, const uint8_t *buf, size_t len) +{ + if (debug) { + int i; + printf("%s [", label); + for (i = 0; i < len; ++i) + printf(" %02x", buf[i]); + printf(" ]\n"); + } +} + +static void i2c_close(void) +{ + close(i2cfd); +} + +static int i2c_open(void) +{ + if (i2cfd >= 0) + return 0; + + i2cfd = open(I2C_dev, O_RDWR); + if (i2cfd < 0) { + fprintf(stderr, "Unable to open %s: ", I2C_dev); + perror(""); + i2cfd = 0; + return 1; + } + + if (ioctl(i2cfd, I2C_SLAVE, I2C_addr) < 0) { + fprintf(stderr, "Unable to set I2C slave device 0x%02x: ", I2C_addr); + perror(""); + return 1; + } + + if (atexit(i2c_close) != 0) { + fprintf(stderr, "Unable to set I2C atexit handler."); + return 1; + } + + return 0; +} + +static int i2c_write(const uint8_t *buf, size_t len) +{ + if (i2c_open() != 0) + return 1; + + dump("write ", buf, len); + + if (write(i2cfd, buf, len) != len) { + perror("i2c write failed"); + return 1; + } + + return 0; +} + +static int i2c_read(uint8_t *b) +{ + if (i2c_open() != 0) + return 1; + + /* read() on the i2c device only returns one byte at a time, + * and hal_io_get_resp() needs to parse the response one byte at a time + */ + if (read(i2cfd, b, 1) != 1) { + perror("i2c read failed"); + return 1; + } + + return 0; +} + +/* ---------------- test-case low-level code ---------------- */ + +/* coretest command codes */ +#define SOC 0x55 +#define EOC 0xaa +#define READ_CMD 0x10 +#define WRITE_CMD 0x11 +#define RESET_CMD 0x01 + +/* coretest response codes */ +#define SOR 0xaa +#define EOR 0x55 +#define READ_OK 0x7f +#define WRITE_OK 0x7e +#define RESET_OK 0x7d +#define UNKNOWN 0xfe +#define ERROR 0xfd + +static int hal_io_send_write_cmd(off_t offset, const uint8_t *data) +{ + uint8_t buf[9] = { SOC, WRITE_CMD, (offset >> 8) & 0xff, offset & 0xff, + data[0], data[1], data[2], data[3], EOC }; + + return i2c_write(buf, sizeof(buf)); +} + +static int hal_io_send_read_cmd(off_t offset) +{ + uint8_t buf[5] = { SOC, READ_CMD, (offset >> 8) & 0xff, offset & 0xff, EOC }; + + return i2c_write(buf, sizeof(buf)); +} + +static int hal_io_get_resp(uint8_t *buf, size_t len) +{ + int i; + + for (i = 0; i < len; ++i) { + if (i2c_read(&buf[i]) != 0) + return 1; + if ((i == 0) && (buf[i] != SOR)) { + /* we've gotten out of sync, and there's probably nothing we can do */ + fprintf(stderr, "response byte 0: expected 0x%02x (SOR), got 0x%02x\n", + SOR, buf[0]); + return 1; + } + else if (i == 1) { /* response code */ + switch (buf[i]) { + case READ_OK: + len = 9; + break; + case WRITE_OK: + len = 5; + break; + case RESET_OK: + len = 3; + break; + case ERROR: + case UNKNOWN: + len = 4; + break; + default: + /* we've gotten out of sync, and there's probably nothing we can do */ + fprintf(stderr, "unknown response code 0x%02x\n", buf[i]); + return 1; + } + } + } + + dump("read ", buf, len); + + return 0; +} + +static int hal_io_compare(uint8_t *buf, const uint8_t *expected, size_t len) +{ + int i; + + /* start at byte 1 because SOR has already been tested */ + for (i = 1; i < len; ++i) { + if (buf[i] != expected[i]) { + fprintf(stderr, "response byte %d: expected 0x%02x, got 0x%02x\n", + i, expected[i], buf[i]); + return 1; + } + } + + return 0; +} + +static int hal_io_get_write_resp(off_t offset) +{ + uint8_t buf[5]; + uint8_t expected[5] = { SOR, WRITE_OK, (offset >> 8) & 0xff, offset & 0xff, EOR }; + + return + hal_io_get_resp(buf, sizeof(buf)) || + hal_io_compare(buf, expected, sizeof(expected)); +} + +static int hal_io_get_read_resp(off_t offset, uint8_t *data) +{ + uint8_t buf[9]; + uint8_t expected[4] = { SOR, READ_OK, (offset >> 8) & 0xff, offset & 0xff }; + + if ((hal_io_get_resp(buf, sizeof(buf)) != 0) || + (hal_io_compare(buf, expected, 4) != 0) || buf[8] != EOR) + return 1; + + data[0] = buf[4]; + data[1] = buf[5]; + data[2] = buf[6]; + data[3] = buf[7]; + + return 0; +} + +static int hal_io_get_read_resp_expected(off_t offset, const uint8_t *data) +{ + uint8_t buf[9]; + uint8_t expected[9] = { SOR, READ_OK, (offset >> 8) & 0xff, offset & 0xff, + data[0], data[1], data[2], data[3], EOR }; + + dump("expect", expected, 9); + + return (hal_io_get_resp(buf, sizeof(buf)) || + hal_io_compare(buf, expected, sizeof(buf))); +} + +int hal_io_write(off_t offset, const uint8_t *buf, size_t len) +{ + for (; len > 0; offset++, buf += 4, len -= 4) { + if (hal_io_send_write_cmd(offset, buf) || + hal_io_get_write_resp(offset)) + return 1; + } + + return 0; +} + +int hal_io_read(off_t offset, uint8_t *buf, size_t len) +{ + for (; len > 0; offset++, buf += 4, len -= 4) { + if (hal_io_send_read_cmd(offset) || + hal_io_get_read_resp(offset, buf)) + return 1; + } + + return 0; +} + +int hal_io_expected(off_t offset, const uint8_t *buf, size_t len) +{ + for (; len > 0; offset++, buf += 4, len -= 4) { + if (hal_io_send_read_cmd(offset) || + hal_io_get_read_resp_expected(offset, buf)) + return 1; + } + + return 0; +} + +int hal_io_init(off_t offset) +{ + uint8_t buf[4] = { 0, 0, 0, CTRL_INIT }; + + return hal_io_write(offset, buf, 4); +} + +int hal_io_next(off_t offset) +{ + uint8_t buf[4] = { 0, 0, 0, CTRL_NEXT }; + + return hal_io_write(offset, buf, 4); +} + +int hal_io_wait(off_t offset, uint8_t status, int *count) +{ + uint8_t buf[4]; + int i; + + for (i = 1; ; ++i) { + if (count && (*count > 0) && (i >= *count)) { + fprintf(stderr, "hal_io_wait timed out\n"); + return 1; + } + if (hal_io_read(offset, buf, 4) != 0) + return -1; + if (buf[3] & status) { + if (count) + *count = i; + return 0; + } + } +} + +int hal_io_wait_ready(off_t offset) +{ + int limit = 10; + return hal_io_wait(offset, STATUS_READY, &limit); +} + +int hal_io_wait_valid(off_t offset) +{ + int limit = 10; + return hal_io_wait(offset, STATUS_VALID, &limit); +} |