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-rw-r--r--hal_io_i2c.c339
1 files changed, 339 insertions, 0 deletions
diff --git a/hal_io_i2c.c b/hal_io_i2c.c
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+/*
+ * 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);
+}