* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
***************************************************************************/
+
+/* 2014-12: Addition of the SWD protocol support is based on the initial work
+ * on bcm2835gpio.c by Paul Fertser and modifications by Jean-Christian de Rivaz. */
+
/**
* @file
* This driver implements a bitbang jtag interface using gpio lines via
}
snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/value", gpio);
- if (is_output)
- ret = open(buf, O_WRONLY | O_NONBLOCK | O_SYNC);
- else
- ret = open(buf, O_RDONLY | O_NONBLOCK | O_SYNC);
-
- if (ret < 0)
+ ret = open(buf, O_RDWR | O_NONBLOCK | O_SYNC);
+ if (ret < 0) {
+ LOG_ERROR("Couldn't open value for gpio %d", gpio);
+ perror("sysfsgpio: ");
unexport_sysfs_gpio(gpio);
+ }
return ret;
}
+/* gpio numbers for each gpio. Negative values are invalid */
+static int tck_gpio = -1;
+static int tms_gpio = -1;
+static int tdi_gpio = -1;
+static int tdo_gpio = -1;
+static int trst_gpio = -1;
+static int srst_gpio = -1;
+static int swclk_gpio = -1;
+static int swdio_gpio = -1;
+
/*
* file descriptors for /sys/class/gpio/gpioXX/value
* Set up during init.
static int tdo_fd = -1;
static int trst_fd = -1;
static int srst_fd = -1;
+static int swclk_fd = -1;
+static int swdio_fd = -1;
+
+static int last_swclk;
+static int last_swdio;
+static bool last_stored;
+static bool swdio_input;
+
+static void sysfsgpio_swdio_drive(bool is_output)
+{
+ char buf[40];
+ int ret;
+
+ snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/direction", swdio_gpio);
+ ret = open_write_close(buf, is_output ? "high" : "in");
+ if (ret < 0) {
+ LOG_ERROR("Couldn't set direction for gpio %d", swdio_gpio);
+ perror("sysfsgpio: ");
+ }
+
+ last_stored = false;
+ swdio_input = !is_output;
+}
+
+static int sysfsgpio_swdio_read(void)
+{
+ char buf[1];
+
+ /* important to seek to signal sysfs of new read */
+ lseek(swdio_fd, 0, SEEK_SET);
+ int ret = read(swdio_fd, &buf, sizeof(buf));
+
+ if (ret < 0) {
+ LOG_WARNING("reading swdio failed");
+ return 0;
+ }
+
+ return buf[0] == '1';
+}
+
+static void sysfsgpio_swdio_write(int swclk, int swdio)
+{
+ const char one[] = "1";
+ const char zero[] = "0";
+
+ size_t bytes_written;
+
+ if (!swdio_input) {
+ if (!last_stored || (swdio != last_swdio)) {
+ bytes_written = write(swdio_fd, swdio ? &one : &zero, 1);
+ if (bytes_written != 1)
+ LOG_WARNING("writing swdio failed");
+ }
+ }
+
+ /* write swclk last */
+ if (!last_stored || (swclk != last_swclk)) {
+ bytes_written = write(swclk_fd, swclk ? &one : &zero, 1);
+ if (bytes_written != 1)
+ LOG_WARNING("writing swclk failed");
+ }
+
+ last_swdio = swdio;
+ last_swclk = swclk;
+ last_stored = true;
+}
/*
* Bitbang interface read of TDO
*/
static void sysfsgpio_write(int tck, int tms, int tdi)
{
+ if (swd_mode) {
+ sysfsgpio_swdio_write(tck, tdi);
+ return;
+ }
+
const char one[] = "1";
const char zero[] = "0";
*/
static void sysfsgpio_reset(int trst, int srst)
{
+ LOG_DEBUG("sysfsgpio_reset");
const char one[] = "1";
const char zero[] = "0";
size_t bytes_written;
}
}
-/* gpio numbers for each gpio. Negative values are invalid */
-static int tck_gpio = -1;
-static int tms_gpio = -1;
-static int tdi_gpio = -1;
-static int tdo_gpio = -1;
-static int trst_gpio = -1;
-static int srst_gpio = -1;
-
COMMAND_HANDLER(sysfsgpio_handle_jtag_gpionums)
{
if (CMD_ARGC == 4) {
return ERROR_OK;
}
+COMMAND_HANDLER(sysfsgpio_handle_swd_gpionums)
+{
+ if (CMD_ARGC == 2) {
+ COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
+ COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
+ } else if (CMD_ARGC != 0) {
+ return ERROR_COMMAND_SYNTAX_ERROR;
+ }
+
+ command_print(CMD_CTX,
+ "SysfsGPIO nums: swclk = %d, swdio = %d",
+ swclk_gpio, swdio_gpio);
+
+ return ERROR_OK;
+}
+
+COMMAND_HANDLER(sysfsgpio_handle_swd_gpionum_swclk)
+{
+ if (CMD_ARGC == 1)
+ COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
+
+ command_print(CMD_CTX, "SysfsGPIO num: swclk = %d", swclk_gpio);
+ return ERROR_OK;
+}
+
+COMMAND_HANDLER(sysfsgpio_handle_swd_gpionum_swdio)
+{
+ if (CMD_ARGC == 1)
+ COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
+
+ command_print(CMD_CTX, "SysfsGPIO num: swdio = %d", swdio_gpio);
+ return ERROR_OK;
+}
+
static const struct command_registration sysfsgpio_command_handlers[] = {
{
.name = "sysfsgpio_jtag_nums",
.mode = COMMAND_CONFIG,
.help = "gpio number for trst.",
},
+ {
+ .name = "sysfsgpio_swd_nums",
+ .handler = &sysfsgpio_handle_swd_gpionums,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio numbers for swclk, swdio. (in that order)",
+ .usage = "(swclk swdio)* ",
+ },
+ {
+ .name = "sysfsgpio_swclk_num",
+ .handler = &sysfsgpio_handle_swd_gpionum_swclk,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio number for swclk.",
+ },
+ {
+ .name = "sysfsgpio_swdio_num",
+ .handler = &sysfsgpio_handle_swd_gpionum_swdio,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio number for swdio.",
+ },
COMMAND_REGISTRATION_DONE
};
static int sysfsgpio_init(void);
static int sysfsgpio_quit(void);
+static const char * const sysfsgpio_transports[] = { "jtag", "swd", NULL };
+
struct jtag_interface sysfsgpio_interface = {
.name = "sysfsgpio",
.supported = DEBUG_CAP_TMS_SEQ,
.execute_queue = bitbang_execute_queue,
- .transports = jtag_only,
+ .transports = sysfsgpio_transports,
+ .swd = &bitbang_swd,
.commands = sysfsgpio_command_handlers,
.init = sysfsgpio_init,
.quit = sysfsgpio_quit,
.read = sysfsgpio_read,
.write = sysfsgpio_write,
.reset = sysfsgpio_reset,
+ .swdio_read = sysfsgpio_swdio_read,
+ .swdio_drive = sysfsgpio_swdio_drive,
.blink = 0
};
cleanup_fd(srst_fd, srst_gpio);
}
+static bool sysfsgpio_jtag_mode_possible(void)
+{
+ if (!is_gpio_valid(tck_gpio))
+ return 0;
+ if (!is_gpio_valid(tms_gpio))
+ return 0;
+ if (!is_gpio_valid(tdi_gpio))
+ return 0;
+ if (!is_gpio_valid(tdo_gpio))
+ return 0;
+ return 1;
+}
+
+static bool sysfsgpio_swd_mode_possible(void)
+{
+ if (!is_gpio_valid(swclk_gpio))
+ return 0;
+ if (!is_gpio_valid(swdio_gpio))
+ return 0;
+ return 1;
+}
+
static int sysfsgpio_init(void)
{
bitbang_interface = &sysfsgpio_bitbang;
- LOG_INFO("SysfsGPIO JTAG bitbang driver");
-
- if (!(is_gpio_valid(tck_gpio)
- && is_gpio_valid(tms_gpio)
- && is_gpio_valid(tdi_gpio)
- && is_gpio_valid(tdo_gpio))) {
- if (!is_gpio_valid(tck_gpio))
- LOG_ERROR("gpio num for tck is invalid");
- if (!is_gpio_valid(tms_gpio))
- LOG_ERROR("gpio num for tms is invalid");
- if (!is_gpio_valid(tdo_gpio))
- LOG_ERROR("gpio num for tdo is invalid");
- if (!is_gpio_valid(tdi_gpio))
- LOG_ERROR("gpio num for tdi is invalid");
-
- LOG_ERROR("Require tck, tms, tdi and tdo gpios to all be specified");
- return ERROR_JTAG_INIT_FAILED;
- }
+ LOG_INFO("SysfsGPIO JTAG/SWD bitbang driver");
- if (!is_gpio_valid(trst_gpio) && !is_gpio_valid(srst_gpio)) {
- LOG_ERROR("Require at least one of trst or srst gpios to be specified");
+ if (sysfsgpio_jtag_mode_possible()) {
+ if (sysfsgpio_swd_mode_possible())
+ LOG_INFO("JTAG and SWD modes enabled");
+ else
+ LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
+ if (!is_gpio_valid(trst_gpio) && !is_gpio_valid(srst_gpio)) {
+ LOG_ERROR("Require at least one of trst or srst gpios to be specified");
+ return ERROR_JTAG_INIT_FAILED;
+ }
+ } else if (sysfsgpio_swd_mode_possible()) {
+ LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
+ } else {
+ LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
return ERROR_JTAG_INIT_FAILED;
}
+
/*
* Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
* as outputs. Drive TDI and TCK low, and TMS/TRST/SRST high.
+ * For SWD, SWCLK and SWDIO are configures as output high.
*/
- tck_fd = setup_sysfs_gpio(tck_gpio, 1, 0);
- if (tck_fd < 0)
- goto out_error;
+ if (tck_gpio >= 0) {
+ tck_fd = setup_sysfs_gpio(tck_gpio, 1, 0);
+ if (tck_fd < 0)
+ goto out_error;
+ }
- tms_fd = setup_sysfs_gpio(tms_gpio, 1, 1);
- if (tms_fd < 0)
- goto out_error;
+ if (tms_gpio >= 0) {
+ tms_fd = setup_sysfs_gpio(tms_gpio, 1, 1);
+ if (tms_fd < 0)
+ goto out_error;
+ }
- tdi_fd = setup_sysfs_gpio(tdi_gpio, 1, 0);
- if (tdi_fd < 0)
- goto out_error;
+ if (tdi_gpio >= 0) {
+ tdi_fd = setup_sysfs_gpio(tdi_gpio, 1, 0);
+ if (tdi_fd < 0)
+ goto out_error;
+ }
- tdo_fd = setup_sysfs_gpio(tdo_gpio, 0, 0);
- if (tdo_fd < 0)
- goto out_error;
+ if (tdo_gpio >= 0) {
+ tdo_fd = setup_sysfs_gpio(tdo_gpio, 0, 0);
+ if (tdo_fd < 0)
+ goto out_error;
+ }
/* assume active low*/
- if (trst_gpio > 0) {
+ if (trst_gpio >= 0) {
trst_fd = setup_sysfs_gpio(trst_gpio, 1, 1);
if (trst_fd < 0)
goto out_error;
}
/* assume active low*/
- if (srst_gpio > 0) {
+ if (srst_gpio >= 0) {
srst_fd = setup_sysfs_gpio(srst_gpio, 1, 1);
if (srst_fd < 0)
goto out_error;
}
+ if (swclk_gpio >= 0) {
+ swclk_fd = setup_sysfs_gpio(swclk_gpio, 1, 0);
+ if (swclk_fd < 0)
+ goto out_error;
+ }
+
+ if (swdio_gpio >= 0) {
+ swdio_fd = setup_sysfs_gpio(swdio_gpio, 1, 0);
+ if (swdio_fd < 0)
+ goto out_error;
+ }
+
+ if (sysfsgpio_swd_mode_possible()) {
+ if (swd_mode)
+ bitbang_swd_switch_seq(NULL, JTAG_TO_SWD);
+ else
+ bitbang_swd_switch_seq(NULL, SWD_TO_JTAG);
+ }
+
return ERROR_OK;
out_error:
projects / openocd / commitdiff