Add SWD protocol support to sysfsgpio

Based on the initial work on bcm2835gpio.c by Paul Fertser with many
additions. Modifications to the GPIO handling was minimal in this
patch. A more big modification is required before cleanup the
interface between bitbang and sysfsgpio.

Change-Id: I54bf2a2aa2ca059368b0e0e105dff6084b73d624
Signed-off-by: Jean-Christian de Rivaz <jc@eclis.ch>
Reviewed-on: http://openocd.zylin.com/2438
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
This commit is contained in:
Jean-Christian de Rivaz 2014-12-11 17:50:33 +01:00 committed by Paul Fertser
parent e971c7f423
commit e290cb76c8
1 changed files with 228 additions and 48 deletions

View File

@ -16,6 +16,10 @@
* 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
@ -139,17 +143,26 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
}
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.
@ -160,6 +173,72 @@ static int tdi_fd = -1;
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
@ -191,6 +270,11 @@ static int sysfsgpio_read(void)
*/
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";
@ -239,6 +323,7 @@ static void sysfsgpio_write(int tck, int tms, int tdi)
*/
static void sysfsgpio_reset(int trst, int srst)
{
LOG_DEBUG("sysfsgpio_reset");
const char one[] = "1";
const char zero[] = "0";
size_t bytes_written;
@ -258,14 +343,6 @@ static void sysfsgpio_reset(int trst, int srst)
}
}
/* 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) {
@ -338,6 +415,40 @@ COMMAND_HANDLER(sysfsgpio_handle_jtag_gpionum_trst)
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",
@ -382,17 +493,39 @@ static const struct command_registration sysfsgpio_command_handlers[] = {
.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,
@ -402,6 +535,8 @@ static struct bitbang_interface sysfsgpio_bitbang = {
.read = sysfsgpio_read,
.write = sysfsgpio_write,
.reset = sysfsgpio_reset,
.swdio_read = sysfsgpio_swdio_read,
.swdio_drive = sysfsgpio_swdio_drive,
.blink = 0
};
@ -426,68 +561,113 @@ static void cleanup_all_fds(void)
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");
LOG_INFO("SysfsGPIO JTAG/SWD 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");
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;
}
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;
}
/*
* 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: