* 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. *
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
***************************************************************************/
+
+/* 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
#include "bitbang.h"
-#include "interface.h"
+#include <jtag/interface.h>
#include <jtag/commands.h>
+/* YUK! - but this is currently a global.... */
+extern struct jtag_interface *jtag_interface;
+
/**
* Function bitbang_stableclocks
* issues a number of clock cycles while staying in a stable state.
*/
static void 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
- {
+ else {
LOG_ERROR("BUG: %i is not a valid end state", state);
exit(-1);
}
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);
tap_set_state(tap_get_end_state());
}
+/**
+ * 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;
+
+ DEBUG_JTAG_IO("TMS: %d bits", num_bits);
+
+ int tms = 0;
+ 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);
+ }
+ bitbang_interface->write(CLOCK_IDLE(), tms, 0);
+
+ return ERROR_OK;
+}
+
static void bitbang_path_move(struct pathmove_command *cmd)
{
int num_states = cmd->num_states;
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);
}
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);
}
/* execute num_cycles */
- for (i = 0; i < num_cycles; i++)
- {
+ for (i = 0; i < num_cycles; i++) {
bitbang_interface->write(0, 0, 0);
bitbang_interface->write(1, 0, 0);
}
bitbang_state_move(0);
}
-
static void 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++)
- {
+ for (i = 0; i < num_cycles; i++) {
bitbang_interface->write(1, tms, 0);
bitbang_interface->write(0, tms, 0);
}
}
-
-
static void bitbang_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size)
{
tap_state_t saved_end_state = tap_get_end_state();
int 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(saved_end_state);
}
- for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
- {
+ for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++) {
int val = 0;
int tms = (bit_cnt == scan_size-1) ? 1 : 0;
int tdi;
bitbang_interface->write(1, tms, tdi);
- if (type != SCAN_OUT)
- {
+ if (type != SCAN_OUT) {
if (val)
buffer[bytec] |= bcval;
else
}
}
- 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.
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);
}
if (bitbang_interface->blink)
bitbang_interface->blink(1);
- while (cmd)
- {
- switch (cmd->type)
- {
+ 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);
+ 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)))
- {
+ 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;
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));
+ LOG_DEBUG("runtest %i cycles, end in %s",
+ cmd->cmd.runtest->num_cycles,
+ tap_state_name(cmd->cmd.runtest->end_state));
#endif
bitbang_end_state(cmd->cmd.runtest->end_state);
bitbang_runtest(cmd->cmd.runtest->num_cycles);
bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles);
break;
- case JTAG_STATEMOVE:
+ case JTAG_TLR_RESET:
#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("statemove end in %s", tap_state_name(cmd->cmd.statemove->end_state));
+ LOG_DEBUG("statemove end in %s",
+ tap_state_name(cmd->cmd.statemove->end_state));
#endif
bitbang_end_state(cmd->cmd.statemove->end_state);
bitbang_state_move(0);
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]));
+ 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);
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));
+ 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);
#endif
jtag_sleep(cmd->cmd.sleep->us);
break;
+ case JTAG_TMS:
+ retval = bitbang_execute_tms(cmd);
+ break;
default:
LOG_ERROR("BUG: unknown JTAG command type encountered");
exit(-1);
return retval;
}
+
+
+bool swd_mode;
+static int queued_retval;
+
+static int bitbang_swd_init(void)
+{
+ LOG_DEBUG("bitbang_swd_init");
+ swd_mode = true;
+ return ERROR_OK;
+}
+
+static void bitbang_exchange(bool rnw, uint8_t buf[], unsigned int offset, unsigned int bit_cnt)
+{
+ LOG_DEBUG("bitbang_exchange");
+ int tdi;
+
+ for (unsigned int i = offset; i < bit_cnt + offset; i++) {
+ int bytec = i/8;
+ int bcval = 1 << (i % 8);
+ tdi = !rnw && (buf[bytec] & bcval);
+
+ bitbang_interface->write(0, 0, tdi);
+
+ if (rnw && buf) {
+ if (bitbang_interface->swdio_read())
+ buf[bytec] |= bcval;
+ else
+ buf[bytec] &= ~bcval;
+ }
+
+ bitbang_interface->write(1, 0, tdi);
+ }
+}
+
+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_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_exchange(false, (uint8_t *)swd_seq_jtag_to_swd, 0, swd_seq_jtag_to_swd_len);
+ break;
+ case SWD_TO_JTAG:
+ LOG_DEBUG("SWD-to-JTAG");
+ bitbang_exchange(false, (uint8_t *)swd_seq_swd_to_jtag, 0, swd_seq_swd_to_jtag_len);
+ break;
+ default:
+ LOG_ERROR("Sequence %d not supported", seq);
+ return ERROR_FAIL;
+ }
+
+ return ERROR_OK;
+}
+
+void bitbang_switch_to_swd(void)
+{
+ LOG_DEBUG("bitbang_switch_to_swd");
+ bitbang_exchange(false, (uint8_t *)swd_seq_jtag_to_swd, 0, swd_seq_jtag_to_swd_len);
+}
+
+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 | (1 << 7);
+ bitbang_exchange(false, &cmd, 0, 8);
+
+ bitbang_interface->swdio_drive(false);
+ bitbang_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 %s 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_RnW ? "read" : "write",
+ (cmd & SWD_CMD_A32) >> 1,
+ data);
+
+ switch (ack) {
+ case SWD_ACK_OK:
+ if (parity != parity_u32(data)) {
+ LOG_DEBUG("Wrong parity detected");
+ queued_retval = ERROR_FAIL;
+ return;
+ }
+ if (value)
+ *value = data;
+ if (cmd & SWD_CMD_APnDP)
+ bitbang_exchange(true, NULL, 0, ap_delay_clk);
+ return;
+ case SWD_ACK_WAIT:
+ LOG_DEBUG("SWD_ACK_WAIT");
+ swd_clear_sticky_errors();
+ break;
+ case SWD_ACK_FAULT:
+ LOG_DEBUG("SWD_ACK_FAULT");
+ queued_retval = ack;
+ return;
+ default:
+ LOG_DEBUG("No valid acknowledge: ack=%d", ack);
+ queued_retval = ack;
+ 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;
+ }
+
+ 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 | (1 << 7);
+ bitbang_exchange(false, &cmd, 0, 8);
+
+ bitbang_interface->swdio_drive(false);
+ bitbang_exchange(true, trn_ack_data_parity_trn, 0, 1 + 3 + 1);
+ bitbang_interface->swdio_drive(true);
+ bitbang_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 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_RnW ? "read" : "write",
+ (cmd & SWD_CMD_A32) >> 1,
+ buf_get_u32(trn_ack_data_parity_trn, 1 + 3 + 1, 32));
+
+ switch (ack) {
+ case SWD_ACK_OK:
+ if (cmd & SWD_CMD_APnDP)
+ bitbang_exchange(true, NULL, 0, ap_delay_clk);
+ return;
+ case SWD_ACK_WAIT:
+ LOG_DEBUG("SWD_ACK_WAIT");
+ swd_clear_sticky_errors();
+ break;
+ case SWD_ACK_FAULT:
+ LOG_DEBUG("SWD_ACK_FAULT");
+ queued_retval = ack;
+ return;
+ default:
+ LOG_DEBUG("No valid acknowledge: ack=%d", ack);
+ queued_retval = ack;
+ 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_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,
+};