* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
- * along with this program; if not, write to the *
- * Free Software Foundation, Inc., *
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
+ * along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
+
+/* 2014-12: Addition of the SWD protocol support is based on the initial work
+ * by Paul Fertser and modifications by Jean-Christian de Rivaz. */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
* this function checks the current stable state to decide on the value of TMS
* to use.
*/
-static void bitbang_stableclocks(int num_cycles);
+static int bitbang_stableclocks(int num_cycles);
+static void bitbang_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk);
struct bitbang_interface *bitbang_interface;
*/
#define CLOCK_IDLE() 0
-
/* The bitbang driver leaves the TCK 0 when in idle */
static void bitbang_end_state(tap_state_t state)
{
- if (tap_is_state_stable(state))
- tap_set_end_state(state);
- else
- {
- LOG_ERROR("BUG: %i is not a valid end state", state);
- exit(-1);
- }
+ assert(tap_is_state_stable(state));
+ tap_set_end_state(state);
}
-static void bitbang_state_move(int skip)
+static int bitbang_state_move(int skip)
{
int i = 0, tms = 0;
uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
- for (i = skip; i < tms_count; i++)
- {
+ for (i = skip; i < tms_count; i++) {
tms = (tms_scan >> i) & 1;
- bitbang_interface->write(0, tms, 0);
- bitbang_interface->write(1, tms, 0);
+ if (bitbang_interface->write(0, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
+ if (bitbang_interface->write(1, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
}
- bitbang_interface->write(CLOCK_IDLE(), tms, 0);
+ if (bitbang_interface->write(CLOCK_IDLE(), tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
tap_set_state(tap_get_end_state());
+ return ERROR_OK;
}
-
/**
* Clock a bunch of TMS (or SWDIO) transitions, to change the JTAG
* (or SWD) state machine.
*/
static int bitbang_execute_tms(struct jtag_command *cmd)
{
- unsigned num_bits = cmd->cmd.tms->num_bits;
- const uint8_t *bits = cmd->cmd.tms->bits;
+ unsigned num_bits = cmd->cmd.tms->num_bits;
+ const uint8_t *bits = cmd->cmd.tms->bits;
- DEBUG_JTAG_IO("TMS: %d bits", num_bits);
+ LOG_DEBUG_IO("TMS: %d bits", num_bits);
int tms = 0;
- for (unsigned i = 0; i < num_bits; i++)
- {
+ for (unsigned i = 0; i < num_bits; i++) {
tms = ((bits[i/8] >> (i % 8)) & 1);
- bitbang_interface->write(0, tms, 0);
- bitbang_interface->write(1, tms, 0);
+ if (bitbang_interface->write(0, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
+ if (bitbang_interface->write(1, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
}
- bitbang_interface->write(CLOCK_IDLE(), tms, 0);
+ if (bitbang_interface->write(CLOCK_IDLE(), tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
return ERROR_OK;
}
-
-static void bitbang_path_move(struct pathmove_command *cmd)
+static int bitbang_path_move(struct pathmove_command *cmd)
{
int num_states = cmd->num_states;
int state_count;
int tms = 0;
state_count = 0;
- while (num_states)
- {
+ while (num_states) {
if (tap_state_transition(tap_get_state(), false) == cmd->path[state_count])
- {
tms = 0;
- }
else if (tap_state_transition(tap_get_state(), true) == cmd->path[state_count])
- {
tms = 1;
- }
- else
- {
- LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(cmd->path[state_count]));
+ else {
+ LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
+ tap_state_name(tap_get_state()),
+ tap_state_name(cmd->path[state_count]));
exit(-1);
}
- bitbang_interface->write(0, tms, 0);
- bitbang_interface->write(1, tms, 0);
+ if (bitbang_interface->write(0, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
+ if (bitbang_interface->write(1, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
tap_set_state(cmd->path[state_count]);
state_count++;
num_states--;
}
- bitbang_interface->write(CLOCK_IDLE(), tms, 0);
+ if (bitbang_interface->write(CLOCK_IDLE(), tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
tap_set_end_state(tap_get_state());
+ return ERROR_OK;
}
-static void bitbang_runtest(int num_cycles)
+static int bitbang_runtest(int num_cycles)
{
int i;
tap_state_t saved_end_state = tap_get_end_state();
/* only do a state_move when we're not already in IDLE */
- if (tap_get_state() != TAP_IDLE)
- {
+ if (tap_get_state() != TAP_IDLE) {
bitbang_end_state(TAP_IDLE);
- bitbang_state_move(0);
+ if (bitbang_state_move(0) != ERROR_OK)
+ return ERROR_FAIL;
}
/* execute num_cycles */
- for (i = 0; i < num_cycles; i++)
- {
- bitbang_interface->write(0, 0, 0);
- bitbang_interface->write(1, 0, 0);
+ for (i = 0; i < num_cycles; i++) {
+ if (bitbang_interface->write(0, 0, 0) != ERROR_OK)
+ return ERROR_FAIL;
+ if (bitbang_interface->write(1, 0, 0) != ERROR_OK)
+ return ERROR_FAIL;
}
- bitbang_interface->write(CLOCK_IDLE(), 0, 0);
+ if (bitbang_interface->write(CLOCK_IDLE(), 0, 0) != ERROR_OK)
+ return ERROR_FAIL;
/* finish in end_state */
bitbang_end_state(saved_end_state);
if (tap_get_state() != tap_get_end_state())
- bitbang_state_move(0);
-}
+ if (bitbang_state_move(0) != ERROR_OK)
+ return ERROR_FAIL;
+ return ERROR_OK;
+}
-static void bitbang_stableclocks(int num_cycles)
+static int bitbang_stableclocks(int num_cycles)
{
int tms = (tap_get_state() == TAP_RESET ? 1 : 0);
int i;
/* send num_cycles clocks onto the cable */
- for (i = 0; i < num_cycles; i++)
- {
- bitbang_interface->write(1, tms, 0);
- bitbang_interface->write(0, tms, 0);
+ for (i = 0; i < num_cycles; i++) {
+ if (bitbang_interface->write(1, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
+ if (bitbang_interface->write(0, tms, 0) != ERROR_OK)
+ return ERROR_FAIL;
}
-}
-
+ return ERROR_OK;
+}
-static void bitbang_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size)
+static int bitbang_scan(bool ir_scan, enum scan_type type, uint8_t *buffer,
+ unsigned scan_size)
{
tap_state_t saved_end_state = tap_get_end_state();
- int bit_cnt;
+ unsigned bit_cnt;
- if (!((!ir_scan && (tap_get_state() == TAP_DRSHIFT)) || (ir_scan && (tap_get_state() == TAP_IRSHIFT))))
- {
+ if (!((!ir_scan &&
+ (tap_get_state() == TAP_DRSHIFT)) ||
+ (ir_scan && (tap_get_state() == TAP_IRSHIFT)))) {
if (ir_scan)
bitbang_end_state(TAP_IRSHIFT);
else
bitbang_end_state(TAP_DRSHIFT);
- bitbang_state_move(0);
+ if (bitbang_state_move(0) != ERROR_OK)
+ return ERROR_FAIL;
bitbang_end_state(saved_end_state);
}
- for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
- {
- int val = 0;
+ size_t buffered = 0;
+ for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++) {
int tms = (bit_cnt == scan_size-1) ? 1 : 0;
int tdi;
int bytec = bit_cnt/8;
if ((type != SCAN_IN) && (buffer[bytec] & bcval))
tdi = 1;
- bitbang_interface->write(0, tms, tdi);
-
- if (type != SCAN_OUT)
- val = bitbang_interface->read();
-
- bitbang_interface->write(1, tms, tdi);
+ if (bitbang_interface->write(0, tms, tdi) != ERROR_OK)
+ return ERROR_FAIL;
+
+ if (type != SCAN_OUT) {
+ if (bitbang_interface->buf_size) {
+ if (bitbang_interface->sample() != ERROR_OK)
+ return ERROR_FAIL;
+ buffered++;
+ } else {
+ switch (bitbang_interface->read()) {
+ case BB_LOW:
+ buffer[bytec] &= ~bcval;
+ break;
+ case BB_HIGH:
+ buffer[bytec] |= bcval;
+ break;
+ default:
+ return ERROR_FAIL;
+ }
+ }
+ }
- if (type != SCAN_OUT)
- {
- if (val)
- buffer[bytec] |= bcval;
- else
- buffer[bytec] &= ~bcval;
+ if (bitbang_interface->write(1, tms, tdi) != ERROR_OK)
+ return ERROR_FAIL;
+
+ if (type != SCAN_OUT && bitbang_interface->buf_size &&
+ (buffered == bitbang_interface->buf_size ||
+ bit_cnt == scan_size - 1)) {
+ for (unsigned i = bit_cnt + 1 - buffered; i <= bit_cnt; i++) {
+ switch (bitbang_interface->read_sample()) {
+ case BB_LOW:
+ buffer[i/8] &= ~(1 << (i % 8));
+ break;
+ case BB_HIGH:
+ buffer[i/8] |= 1 << (i % 8);
+ break;
+ default:
+ return ERROR_FAIL;
+ }
+ }
+ buffered = 0;
}
}
- if (tap_get_state() != tap_get_end_state())
- {
+ if (tap_get_state() != tap_get_end_state()) {
/* we *KNOW* the above loop transitioned out of
* the shift state, so we skip the first state
* and move directly to the end state.
*/
- bitbang_state_move(1);
+ if (bitbang_state_move(1) != ERROR_OK)
+ return ERROR_FAIL;
}
+ return ERROR_OK;
}
int bitbang_execute_queue(void)
{
- struct jtag_command *cmd = jtag_command_queue; /* currently processed command */
+ struct jtag_command *cmd = jtag_command_queue; /* currently processed command */
int scan_size;
enum scan_type type;
uint8_t *buffer;
int retval;
- if (!bitbang_interface)
- {
+ if (!bitbang_interface) {
LOG_ERROR("BUG: Bitbang interface called, but not yet initialized");
exit(-1);
}
*/
retval = ERROR_OK;
- if (bitbang_interface->blink)
- bitbang_interface->blink(1);
+ if (bitbang_interface->blink) {
+ if (bitbang_interface->blink(1) != ERROR_OK)
+ return ERROR_FAIL;
+ }
- while (cmd)
- {
- switch (cmd->type)
- {
- case JTAG_RESET:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
-#endif
- if ((cmd->cmd.reset->trst == 1) || (cmd->cmd.reset->srst && (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
- {
- tap_set_state(TAP_RESET);
- }
- bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
- break;
+ while (cmd) {
+ switch (cmd->type) {
case JTAG_RUNTEST:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("runtest %i cycles, end in %s", cmd->cmd.runtest->num_cycles, tap_state_name(cmd->cmd.runtest->end_state));
-#endif
+ LOG_DEBUG_IO("runtest %i cycles, end in %s",
+ cmd->cmd.runtest->num_cycles,
+ tap_state_name(cmd->cmd.runtest->end_state));
bitbang_end_state(cmd->cmd.runtest->end_state);
- bitbang_runtest(cmd->cmd.runtest->num_cycles);
+ if (bitbang_runtest(cmd->cmd.runtest->num_cycles) != ERROR_OK)
+ return ERROR_FAIL;
break;
case JTAG_STABLECLOCKS:
/* this is only allowed while in a stable state. A check for a stable
* state was done in jtag_add_clocks()
*/
- bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles);
+ if (bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles) != ERROR_OK)
+ return ERROR_FAIL;
break;
- case JTAG_STATEMOVE:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("statemove end in %s", tap_state_name(cmd->cmd.statemove->end_state));
-#endif
+ case JTAG_TLR_RESET:
+ LOG_DEBUG_IO("statemove end in %s",
+ tap_state_name(cmd->cmd.statemove->end_state));
bitbang_end_state(cmd->cmd.statemove->end_state);
- bitbang_state_move(0);
+ if (bitbang_state_move(0) != ERROR_OK)
+ return ERROR_FAIL;
break;
case JTAG_PATHMOVE:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("pathmove: %i states, end in %s", cmd->cmd.pathmove->num_states,
- tap_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
-#endif
- bitbang_path_move(cmd->cmd.pathmove);
+ LOG_DEBUG_IO("pathmove: %i states, end in %s",
+ cmd->cmd.pathmove->num_states,
+ tap_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
+ if (bitbang_path_move(cmd->cmd.pathmove) != ERROR_OK)
+ return ERROR_FAIL;
break;
case JTAG_SCAN:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("%s scan end in %s", (cmd->cmd.scan->ir_scan) ? "IR" : "DR", tap_state_name(cmd->cmd.scan->end_state));
-#endif
bitbang_end_state(cmd->cmd.scan->end_state);
scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
+ LOG_DEBUG_IO("%s scan %d bits; end in %s",
+ (cmd->cmd.scan->ir_scan) ? "IR" : "DR",
+ scan_size,
+ tap_state_name(cmd->cmd.scan->end_state));
type = jtag_scan_type(cmd->cmd.scan);
- bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
+ if (bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer,
+ scan_size) != ERROR_OK)
+ return ERROR_FAIL;
if (jtag_read_buffer(buffer, cmd->cmd.scan) != ERROR_OK)
retval = ERROR_JTAG_QUEUE_FAILED;
- if (buffer)
- free(buffer);
+ free(buffer);
break;
case JTAG_SLEEP:
-#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("sleep %" PRIi32, cmd->cmd.sleep->us);
-#endif
+ LOG_DEBUG_IO("sleep %" PRIu32, cmd->cmd.sleep->us);
jtag_sleep(cmd->cmd.sleep->us);
break;
case JTAG_TMS:
}
cmd = cmd->next;
}
- if (bitbang_interface->blink)
+ if (bitbang_interface->blink) {
+ if (bitbang_interface->blink(0) != ERROR_OK)
+ return ERROR_FAIL;
+ }
+
+ return retval;
+}
+
+static int queued_retval;
+
+static int bitbang_swd_init(void)
+{
+ LOG_DEBUG("bitbang_swd_init");
+ return ERROR_OK;
+}
+
+static void bitbang_swd_exchange(bool rnw, uint8_t buf[], unsigned int offset, unsigned int bit_cnt)
+{
+ LOG_DEBUG("bitbang_swd_exchange");
+
+ if (bitbang_interface->blink) {
+ /* FIXME: we should manage errors */
+ bitbang_interface->blink(1);
+ }
+
+ for (unsigned int i = offset; i < bit_cnt + offset; i++) {
+ int bytec = i/8;
+ int bcval = 1 << (i % 8);
+ int swdio = !rnw && (buf[bytec] & bcval);
+
+ bitbang_interface->swd_write(0, swdio);
+
+ if (rnw && buf) {
+ if (bitbang_interface->swdio_read())
+ buf[bytec] |= bcval;
+ else
+ buf[bytec] &= ~bcval;
+ }
+
+ bitbang_interface->swd_write(1, swdio);
+ }
+
+ if (bitbang_interface->blink) {
+ /* FIXME: we should manage errors */
bitbang_interface->blink(0);
+ }
+}
+
+static int bitbang_swd_switch_seq(enum swd_special_seq seq)
+{
+ LOG_DEBUG("bitbang_swd_switch_seq");
+
+ switch (seq) {
+ case LINE_RESET:
+ LOG_DEBUG("SWD line reset");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_line_reset, 0, swd_seq_line_reset_len);
+ break;
+ case JTAG_TO_SWD:
+ LOG_DEBUG("JTAG-to-SWD");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_jtag_to_swd, 0, swd_seq_jtag_to_swd_len);
+ break;
+ case JTAG_TO_DORMANT:
+ LOG_DEBUG("JTAG-to-DORMANT");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_jtag_to_dormant, 0, swd_seq_jtag_to_dormant_len);
+ break;
+ case SWD_TO_JTAG:
+ LOG_DEBUG("SWD-to-JTAG");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_swd_to_jtag, 0, swd_seq_swd_to_jtag_len);
+ break;
+ case SWD_TO_DORMANT:
+ LOG_DEBUG("SWD-to-DORMANT");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_swd_to_dormant, 0, swd_seq_swd_to_dormant_len);
+ break;
+ case DORMANT_TO_SWD:
+ LOG_DEBUG("DORMANT-to-SWD");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_dormant_to_swd, 0, swd_seq_dormant_to_swd_len);
+ break;
+ case DORMANT_TO_JTAG:
+ LOG_DEBUG("DORMANT-to-JTAG");
+ bitbang_swd_exchange(false, (uint8_t *)swd_seq_dormant_to_jtag, 0, swd_seq_dormant_to_jtag_len);
+ break;
+ default:
+ LOG_ERROR("Sequence %d not supported", seq);
+ return ERROR_FAIL;
+ }
+
+ return ERROR_OK;
+}
+
+static void swd_clear_sticky_errors(void)
+{
+ bitbang_swd_write_reg(swd_cmd(false, false, DP_ABORT),
+ STKCMPCLR | STKERRCLR | WDERRCLR | ORUNERRCLR, 0);
+}
+
+static void bitbang_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay_clk)
+{
+ LOG_DEBUG("bitbang_swd_read_reg");
+ assert(cmd & SWD_CMD_RNW);
+ if (queued_retval != ERROR_OK) {
+ LOG_DEBUG("Skip bitbang_swd_read_reg because queued_retval=%d", queued_retval);
+ return;
+ }
+
+ for (;;) {
+ uint8_t trn_ack_data_parity_trn[DIV_ROUND_UP(4 + 3 + 32 + 1 + 4, 8)];
+
+ cmd |= SWD_CMD_START | SWD_CMD_PARK;
+ bitbang_swd_exchange(false, &cmd, 0, 8);
+
+ bitbang_interface->swdio_drive(false);
+ bitbang_swd_exchange(true, trn_ack_data_parity_trn, 0, 1 + 3 + 32 + 1 + 1);
+ bitbang_interface->swdio_drive(true);
+
+ int ack = buf_get_u32(trn_ack_data_parity_trn, 1, 3);
+ uint32_t data = buf_get_u32(trn_ack_data_parity_trn, 1 + 3, 32);
+ int parity = buf_get_u32(trn_ack_data_parity_trn, 1 + 3 + 32, 1);
+
+ LOG_DEBUG("%s %s read reg %X = %08"PRIx32,
+ ack == SWD_ACK_OK ? "OK" : ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK",
+ cmd & SWD_CMD_APNDP ? "AP" : "DP",
+ (cmd & SWD_CMD_A32) >> 1,
+ data);
+
+ if (ack == SWD_ACK_WAIT) {
+ swd_clear_sticky_errors();
+ continue;
+ } else if (ack != SWD_ACK_OK) {
+ queued_retval = swd_ack_to_error_code(ack);
+ return;
+ }
+
+ if (parity != parity_u32(data)) {
+ LOG_ERROR("Wrong parity detected");
+ queued_retval = ERROR_FAIL;
+ return;
+ }
+ if (value)
+ *value = data;
+ if (cmd & SWD_CMD_APNDP)
+ bitbang_swd_exchange(true, NULL, 0, ap_delay_clk);
+ return;
+ }
+}
+
+static void bitbang_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk)
+{
+ LOG_DEBUG("bitbang_swd_write_reg");
+ assert(!(cmd & SWD_CMD_RNW));
+
+ if (queued_retval != ERROR_OK) {
+ LOG_DEBUG("Skip bitbang_swd_write_reg because queued_retval=%d", queued_retval);
+ return;
+ }
+
+ /* Devices do not reply to DP_TARGETSEL write cmd, ignore received ack */
+ bool check_ack = swd_cmd_returns_ack(cmd);
+
+ for (;;) {
+ uint8_t trn_ack_data_parity_trn[DIV_ROUND_UP(4 + 3 + 32 + 1 + 4, 8)];
+ buf_set_u32(trn_ack_data_parity_trn, 1 + 3 + 1, 32, value);
+ buf_set_u32(trn_ack_data_parity_trn, 1 + 3 + 1 + 32, 1, parity_u32(value));
+
+ cmd |= SWD_CMD_START | SWD_CMD_PARK;
+ bitbang_swd_exchange(false, &cmd, 0, 8);
+
+ bitbang_interface->swdio_drive(false);
+ bitbang_swd_exchange(true, trn_ack_data_parity_trn, 0, 1 + 3 + 1);
+ bitbang_interface->swdio_drive(true);
+ bitbang_swd_exchange(false, trn_ack_data_parity_trn, 1 + 3 + 1, 32 + 1);
+
+ int ack = buf_get_u32(trn_ack_data_parity_trn, 1, 3);
+
+ LOG_DEBUG("%s%s %s write reg %X = %08"PRIx32,
+ check_ack ? "" : "ack ignored ",
+ ack == SWD_ACK_OK ? "OK" : ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK",
+ cmd & SWD_CMD_APNDP ? "AP" : "DP",
+ (cmd & SWD_CMD_A32) >> 1,
+ buf_get_u32(trn_ack_data_parity_trn, 1 + 3 + 1, 32));
+
+ if (check_ack) {
+ if (ack == SWD_ACK_WAIT) {
+ swd_clear_sticky_errors();
+ continue;
+ } else if (ack != SWD_ACK_OK) {
+ queued_retval = swd_ack_to_error_code(ack);
+ return;
+ }
+ }
+
+ if (cmd & SWD_CMD_APNDP)
+ bitbang_swd_exchange(true, NULL, 0, ap_delay_clk);
+ return;
+ }
+}
+
+static int bitbang_swd_run_queue(void)
+{
+ LOG_DEBUG("bitbang_swd_run_queue");
+ /* A transaction must be followed by another transaction or at least 8 idle cycles to
+ * ensure that data is clocked through the AP. */
+ bitbang_swd_exchange(true, NULL, 0, 8);
+
+ int retval = queued_retval;
+ queued_retval = ERROR_OK;
+ LOG_DEBUG("SWD queue return value: %02x", retval);
return retval;
}
+
+const struct swd_driver bitbang_swd = {
+ .init = bitbang_swd_init,
+ .switch_seq = bitbang_swd_switch_seq,
+ .read_reg = bitbang_swd_read_reg,
+ .write_reg = bitbang_swd_write_reg,
+ .run = bitbang_swd_run_queue,
+};