]> git.sur5r.net Git - openocd/blobdiff - src/jtag/core.c
drivers/cmsis-dap: port to common SWD framework
[openocd] / src / jtag / core.c
index d7e1ccec764e50b93f80727185b08be73af44280..1b1106f121ed3741a8af62c9678630e6336246ac 100644 (file)
  *   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.           *
  ***************************************************************************/
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #include "jtag.h"
+#include "swd.h"
 #include "interface.h"
-#include "transport.h"
+#include <transport/transport.h>
 
 #ifdef HAVE_STRINGS_H
 #include <strings.h>
 #include "svf/svf.h"
 #include "xsvf/xsvf.h"
 
-/// The number of JTAG queue flushes (for profiling and debugging purposes).
+/** The number of JTAG queue flushes (for profiling and debugging purposes). */
 static int jtag_flush_queue_count;
 
-// Sleep this # of ms after flushing the queue
-static int jtag_flush_queue_sleep = 0;
+/* Sleep this # of ms after flushing the queue */
+static int jtag_flush_queue_sleep;
 
 static void jtag_add_scan_check(struct jtag_tap *active,
-               void (*jtag_add_scan)(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields, tap_state_t state),
+               void (*jtag_add_scan)(struct jtag_tap *active,
+               int in_num_fields,
+               const struct scan_field *in_fields,
+               tap_state_t state),
                int in_num_fields, struct scan_field *in_fields, tap_state_t state);
 
 /**
@@ -65,8 +70,7 @@ static void jtag_add_scan_check(struct jtag_tap *active,
  */
 static int jtag_error = ERROR_OK;
 
-static const char *jtag_event_strings[] =
-{
+static const char *jtag_event_strings[] = {
        [JTAG_TRST_ASSERTED] = "TAP reset",
        [JTAG_TAP_EVENT_SETUP] = "TAP setup",
        [JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
@@ -85,12 +89,7 @@ static int jtag_srst = -1;
 /**
  * List all TAPs that have been created.
  */
-static struct jtag_tap *__jtag_all_taps = NULL;
-/**
- * The number of TAPs in the __jtag_all_taps list, used to track the
- * assigned chain position to new TAPs
- */
-static unsigned jtag_num_taps = 0;
+static struct jtag_tap *__jtag_all_taps;
 
 static enum reset_types jtag_reset_config = RESET_NONE;
 tap_state_t cmd_queue_cur_state = TAP_RESET;
@@ -98,42 +97,40 @@ tap_state_t cmd_queue_cur_state = TAP_RESET;
 static bool jtag_verify_capture_ir = true;
 static int jtag_verify = 1;
 
-/* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
-static int adapter_nsrst_delay = 0; /* default to no nSRST delay */
-static int jtag_ntrst_delay = 0; /* default to no nTRST delay */
-static int adapter_nsrst_assert_width = 0; /* width of assertion */
-static int jtag_ntrst_assert_width = 0; /* width of assertion */
+/* how long the OpenOCD should wait before attempting JTAG communication after reset lines
+ *deasserted (in ms) */
+static int adapter_nsrst_delay;        /* default to no nSRST delay */
+static int jtag_ntrst_delay;/* default to no nTRST delay */
+static int adapter_nsrst_assert_width; /* width of assertion */
+static int jtag_ntrst_assert_width;    /* width of assertion */
 
 /**
  * Contains a single callback along with a pointer that will be passed
  * when an event occurs.
  */
 struct jtag_event_callback {
-       /// a event callback
+       /** a event callback */
        jtag_event_handler_t callback;
-       /// the private data to pass to the callback
-       voidpriv;
-       /// the next callback
-       struct jtag_event_callbacknext;
+       /** the private data to pass to the callback */
+       void *priv;
+       /** the next callback */
+       struct jtag_event_callback *next;
 };
 
 /* callbacks to inform high-level handlers about JTAG state changes */
 static struct jtag_event_callback *jtag_event_callbacks;
 
 /* speed in kHz*/
-static int speed_khz = 0;
+static int speed_khz;
 /* speed to fallback to when RCLK is requested but not supported */
-static int rclk_fallback_speed_khz = 0;
-static enum {CLOCK_MODE_SPEED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
-static int jtag_speed = 0;
+static int rclk_fallback_speed_khz;
+static enum {CLOCK_MODE_UNSELECTED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
+static int jtag_speed;
 
-static struct jtag_interface *jtag = NULL;
-
-
-const struct swd_driver *swd = NULL;
+static struct jtag_interface *jtag;
 
 /* configuration */
-struct jtag_interface *jtag_interface = NULL;
+struct jtag_interface *jtag_interface;
 
 void jtag_set_flush_queue_sleep(int ms)
 {
@@ -164,6 +161,9 @@ bool is_jtag_poll_safe(void)
         * It is also implicitly disabled while TRST is active and
         * while SRST is gating the JTAG clock.
         */
+       if (!transport_is_jtag())
+               return jtag_poll;
+
        if (!jtag_poll || jtag_trst != 0)
                return false;
        return jtag_srst == 0 || (jtag_reset_config & RESET_SRST_NO_GATING);
@@ -188,15 +188,20 @@ struct jtag_tap *jtag_all_taps(void)
 
 unsigned jtag_tap_count(void)
 {
-       return jtag_num_taps;
+       struct jtag_tap *t = jtag_all_taps();
+       unsigned n = 0;
+       while (t) {
+               n++;
+               t = t->next_tap;
+       }
+       return n;
 }
 
 unsigned jtag_tap_count_enabled(void)
 {
        struct jtag_tap *t = jtag_all_taps();
        unsigned n = 0;
-       while (t)
-       {
+       while (t) {
                if (t->enabled)
                        n++;
                t = t->next_tap;
@@ -204,15 +209,18 @@ unsigned jtag_tap_count_enabled(void)
        return n;
 }
 
-/// Append a new TAP to the chain of all taps.
+/** Append a new TAP to the chain of all taps. */
 void jtag_tap_add(struct jtag_tap *t)
 {
-       t->abs_chain_position = jtag_num_taps++;
+       unsigned jtag_num_taps = 0;
 
        struct jtag_tap **tap = &__jtag_all_taps;
-       while (*tap != NULL)
+       while (*tap != NULL) {
+               jtag_num_taps++;
                tap = &(*tap)->next_tap;
+       }
        *tap = t;
+       t->abs_chain_position = jtag_num_taps;
 }
 
 /* returns a pointer to the n-th device in the scan chain */
@@ -231,8 +239,7 @@ struct jtag_tap *jtag_tap_by_string(const char *s)
        /* try by name first */
        struct jtag_tap *t = jtag_all_taps();
 
-       while (t)
-       {
+       while (t) {
                if (0 == strcmp(t->dotted_name, s))
                        return t;
                t = t->next_tap;
@@ -255,11 +262,10 @@ struct jtag_tap *jtag_tap_by_string(const char *s)
        return t;
 }
 
-struct jtag_tap* jtag_tap_next_enabled(struct jtag_tap* p)
+struct jtag_tap *jtag_tap_next_enabled(struct jtag_tap *p)
 {
        p = p ? p->next_tap : jtag_all_taps();
-       while (p)
-       {
+       while (p) {
                if (p->enabled)
                        return p;
                p = p->next_tap;
@@ -278,12 +284,9 @@ int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
        struct jtag_event_callback **callbacks_p = &jtag_event_callbacks;
 
        if (callback == NULL)
-       {
-               return ERROR_INVALID_ARGUMENTS;
-       }
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
-       if (*callbacks_p)
-       {
+       if (*callbacks_p) {
                while ((*callbacks_p)->next)
                        callbacks_p = &((*callbacks_p)->next);
                callbacks_p = &((*callbacks_p)->next);
@@ -302,14 +305,10 @@ int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
        struct jtag_event_callback **p = &jtag_event_callbacks, *temp;
 
        if (callback == NULL)
-       {
-               return ERROR_INVALID_ARGUMENTS;
-       }
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
-       while (*p)
-       {
-               if (((*p)->priv != priv) || ((*p)->callback != callback))
-               {
+       while (*p) {
+               if (((*p)->priv != priv) || ((*p)->callback != callback)) {
                        p = &(*p)->next;
                        continue;
                }
@@ -328,8 +327,7 @@ int jtag_call_event_callbacks(enum jtag_event event)
 
        LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
 
-       while (callback)
-       {
+       while (callback) {
                struct jtag_event_callback *next;
 
                /* callback may remove itself */
@@ -355,13 +353,8 @@ static void jtag_prelude(tap_state_t state)
        cmd_queue_cur_state = state;
 }
 
-void jtag_alloc_in_value32(struct scan_field *field)
-{
-       interface_jtag_alloc_in_value32(field);
-}
-
 void jtag_add_ir_scan_noverify(struct jtag_tap *active, const struct scan_field *in_fields,
-               tap_state_t state)
+       tap_state_t state)
 {
        jtag_prelude(state);
 
@@ -369,18 +362,20 @@ void jtag_add_ir_scan_noverify(struct jtag_tap *active, const struct scan_field
        jtag_set_error(retval);
 }
 
-static void jtag_add_ir_scan_noverify_callback(struct jtag_tap *active, int dummy, const struct scan_field *in_fields,
-               tap_state_t state)
+static void jtag_add_ir_scan_noverify_callback(struct jtag_tap *active,
+       int dummy,
+       const struct scan_field *in_fields,
+       tap_state_t state)
 {
        jtag_add_ir_scan_noverify(active, in_fields, state);
 }
 
+/* If fields->in_value is filled out, then the captured IR value will be checked */
 void jtag_add_ir_scan(struct jtag_tap *active, struct scan_field *in_fields, tap_state_t state)
 {
        assert(state != TAP_RESET);
 
-       if (jtag_verify && jtag_verify_capture_ir)
-       {
+       if (jtag_verify && jtag_verify_capture_ir) {
                /* 8 x 32 bit id's is enough for all invocations */
 
                /* if we are to run a verification of the ir scan, we need to get the input back.
@@ -388,15 +383,14 @@ void jtag_add_ir_scan(struct jtag_tap *active, struct scan_field *in_fields, tap
                 */
                in_fields->check_value = active->expected;
                in_fields->check_mask = active->expected_mask;
-               jtag_add_scan_check(active, jtag_add_ir_scan_noverify_callback, 1, in_fields, state);
+               jtag_add_scan_check(active, jtag_add_ir_scan_noverify_callback, 1, in_fields,
+                       state);
        } else
-       {
                jtag_add_ir_scan_noverify(active, in_fields, state);
-       }
 }
 
 void jtag_add_plain_ir_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
-               tap_state_t state)
+       tap_state_t state)
 {
        assert(out_bits != NULL);
        assert(state != TAP_RESET);
@@ -409,64 +403,56 @@ void jtag_add_plain_ir_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_b
 }
 
 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
-               uint8_t *in_check_mask, int num_bits);
+                                 uint8_t *in_check_mask, int num_bits);
 
-static int jtag_check_value_mask_callback(jtag_callback_data_t data0, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
+static int jtag_check_value_mask_callback(jtag_callback_data_t data0,
+       jtag_callback_data_t data1,
+       jtag_callback_data_t data2,
+       jtag_callback_data_t data3)
 {
-       return jtag_check_value_inner((uint8_t *)data0, (uint8_t *)data1, (uint8_t *)data2, (int)data3);
+       return jtag_check_value_inner((uint8_t *)data0,
+               (uint8_t *)data1,
+               (uint8_t *)data2,
+               (int)data3);
 }
 
-static void jtag_add_scan_check(struct jtag_tap *active, void (*jtag_add_scan)(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields, tap_state_t state),
-               int in_num_fields, struct scan_field *in_fields, tap_state_t state)
+static void jtag_add_scan_check(struct jtag_tap *active, void (*jtag_add_scan)(
+               struct jtag_tap *active,
+               int in_num_fields,
+               const struct scan_field *in_fields,
+               tap_state_t state),
+       int in_num_fields, struct scan_field *in_fields, tap_state_t state)
 {
-       for (int i = 0; i < in_num_fields; i++)
-       {
-               struct scan_field *field = &in_fields[i];
-               field->allocated = 0;
-               field->modified = 0;
-               if (field->check_value || field->in_value)
-                       continue;
-               interface_jtag_add_scan_check_alloc(field);
-               field->modified = 1;
-       }
-
        jtag_add_scan(active, in_num_fields, in_fields, state);
 
-       for (int i = 0; i < in_num_fields; i++)
-       {
-               if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL))
-               {
+       for (int i = 0; i < in_num_fields; i++) {
+               if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL)) {
                        /* this is synchronous for a minidriver */
-                       jtag_add_callback4(jtag_check_value_mask_callback, (jtag_callback_data_t)in_fields[i].in_value,
+                       jtag_add_callback4(jtag_check_value_mask_callback,
+                               (jtag_callback_data_t)in_fields[i].in_value,
                                (jtag_callback_data_t)in_fields[i].check_value,
                                (jtag_callback_data_t)in_fields[i].check_mask,
                                (jtag_callback_data_t)in_fields[i].num_bits);
                }
-               if (in_fields[i].allocated)
-               {
-                       free(in_fields[i].in_value);
-               }
-               if (in_fields[i].modified)
-               {
-                       in_fields[i].in_value = NULL;
-               }
        }
 }
 
-void jtag_add_dr_scan_check(struct jtag_tap *active, int in_num_fields, struct scan_field *in_fields, tap_state_t state)
+void jtag_add_dr_scan_check(struct jtag_tap *active,
+       int in_num_fields,
+       struct scan_field *in_fields,
+       tap_state_t state)
 {
        if (jtag_verify)
-       {
                jtag_add_scan_check(active, jtag_add_dr_scan, in_num_fields, in_fields, state);
-       } else
-       {
+       else
                jtag_add_dr_scan(active, in_num_fields, in_fields, state);
-       }
 }
 
 
-void jtag_add_dr_scan(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields,
-               tap_state_t state)
+void jtag_add_dr_scan(struct jtag_tap *active,
+       int in_num_fields,
+       const struct scan_field *in_fields,
+       tap_state_t state)
 {
        assert(state != TAP_RESET);
 
@@ -478,7 +464,7 @@ void jtag_add_dr_scan(struct jtag_tap *active, int in_num_fields, const struct s
 }
 
 void jtag_add_plain_dr_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
-               tap_state_t state)
+       tap_state_t state)
 {
        assert(out_bits != NULL);
        assert(state != TAP_RESET);
@@ -534,27 +520,23 @@ void jtag_add_pathmove(int num_states, const tap_state_t *path)
        tap_state_t cur_state = cmd_queue_cur_state;
 
        /* the last state has to be a stable state */
-       if (!tap_is_state_stable(path[num_states - 1]))
-       {
+       if (!tap_is_state_stable(path[num_states - 1])) {
                LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
                jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
                return;
        }
 
-       for (int i = 0; i < num_states; i++)
-       {
-               if (path[i] == TAP_RESET)
-               {
+       for (int i = 0; i < num_states; i++) {
+               if (path[i] == TAP_RESET) {
                        LOG_ERROR("BUG: TAP_RESET is not a valid state for pathmove sequences");
                        jtag_set_error(ERROR_JTAG_STATE_INVALID);
                        return;
                }
 
-               if (tap_state_transition(cur_state, true)  != path[i]
-                 && tap_state_transition(cur_state, false) != path[i])
-               {
+               if (tap_state_transition(cur_state, true) != path[i] &&
+                               tap_state_transition(cur_state, false) != path[i]) {
                        LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
-                                       tap_state_name(cur_state), tap_state_name(path[i]));
+                               tap_state_name(cur_state), tap_state_name(path[i]));
                        jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
                        return;
                }
@@ -571,8 +553,7 @@ int jtag_add_statemove(tap_state_t goal_state)
 {
        tap_state_t cur_state = cmd_queue_cur_state;
 
-       if (goal_state != cur_state)
-       {
+       if (goal_state != cur_state) {
                LOG_DEBUG("cur_state=%s goal_state=%s",
                        tap_state_name(cur_state),
                        tap_state_name(goal_state));
@@ -584,17 +565,15 @@ int jtag_add_statemove(tap_state_t goal_state)
        if (goal_state == TAP_RESET)
                jtag_add_tlr();
        else if (goal_state == cur_state)
-               /* nothing to do */ ;
+               /* nothing to do */;
 
-       else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state))
-       {
+       else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state)) {
                unsigned tms_bits  = tap_get_tms_path(cur_state, goal_state);
                unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
                tap_state_t moves[8];
                assert(tms_count < ARRAY_SIZE(moves));
 
-               for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
-               {
+               for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1) {
                        bool bit = tms_bits & 1;
 
                        cur_state = tap_state_transition(cur_state, bit);
@@ -602,13 +581,9 @@ int jtag_add_statemove(tap_state_t goal_state)
                }
 
                jtag_add_pathmove(tms_count, moves);
-       }
-       else if (tap_state_transition(cur_state, true)  == goal_state
-               ||   tap_state_transition(cur_state, false) == goal_state)
-       {
+       } else if (tap_state_transition(cur_state, true)  == goal_state
+                       || tap_state_transition(cur_state, false) == goal_state)
                jtag_add_pathmove(1, &goal_state);
-       }
-
        else
                return ERROR_FAIL;
 
@@ -624,21 +599,59 @@ void jtag_add_runtest(int num_cycles, tap_state_t state)
 
 void jtag_add_clocks(int num_cycles)
 {
-       if (!tap_is_state_stable(cmd_queue_cur_state))
-       {
-                LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
-                                tap_state_name(cmd_queue_cur_state));
-                jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
-                return;
+       if (!tap_is_state_stable(cmd_queue_cur_state)) {
+               LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
+                       tap_state_name(cmd_queue_cur_state));
+               jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
+               return;
        }
 
-       if (num_cycles > 0)
-       {
+       if (num_cycles > 0) {
                jtag_checks();
                jtag_set_error(interface_jtag_add_clocks(num_cycles));
        }
 }
 
+void swd_add_reset(int req_srst)
+{
+       if (req_srst) {
+               if (!(jtag_reset_config & RESET_HAS_SRST)) {
+                       LOG_ERROR("BUG: can't assert SRST");
+                       jtag_set_error(ERROR_FAIL);
+                       return;
+               }
+               req_srst = 1;
+       }
+
+       /* Maybe change SRST signal state */
+       if (jtag_srst != req_srst) {
+               int retval;
+
+               retval = interface_jtag_add_reset(0, req_srst);
+               if (retval != ERROR_OK)
+                       jtag_set_error(retval);
+               else
+                       retval = jtag_execute_queue();
+
+               if (retval != ERROR_OK) {
+                       LOG_ERROR("TRST/SRST error");
+                       return;
+               }
+
+               /* SRST resets everything hooked up to that signal */
+               jtag_srst = req_srst;
+               if (jtag_srst) {
+                       LOG_DEBUG("SRST line asserted");
+                       if (adapter_nsrst_assert_width)
+                               jtag_add_sleep(adapter_nsrst_assert_width * 1000);
+               } else {
+                       LOG_DEBUG("SRST line released");
+                       if (adapter_nsrst_delay)
+                               jtag_add_sleep(adapter_nsrst_delay * 1000);
+               }
+       }
+}
+
 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 {
        int trst_with_tlr = 0;
@@ -678,7 +691,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
                if (!(jtag_reset_config & RESET_HAS_TRST))
                        trst_with_tlr = 1;
                else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
-                               && !req_srst)
+                        && !req_srst)
                        trst_with_tlr = 1;
                else
                        new_trst = 1;
@@ -703,13 +716,11 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        /* SRST resets everything hooked up to that signal */
        if (jtag_srst != new_srst) {
                jtag_srst = new_srst;
-               if (jtag_srst)
-               {
+               if (jtag_srst) {
                        LOG_DEBUG("SRST line asserted");
                        if (adapter_nsrst_assert_width)
                                jtag_add_sleep(adapter_nsrst_assert_width * 1000);
-               }
-               else {
+               } else {
                        LOG_DEBUG("SRST line released");
                        if (adapter_nsrst_delay)
                                jtag_add_sleep(adapter_nsrst_delay * 1000);
@@ -751,13 +762,13 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 
 void jtag_add_sleep(uint32_t us)
 {
-       /// @todo Here, keep_alive() appears to be a layering violation!!!
+       /** @todo Here, keep_alive() appears to be a layering violation!!! */
        keep_alive();
        jtag_set_error(interface_jtag_add_sleep(us));
 }
 
 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
-               uint8_t *in_check_mask, int num_bits)
+       uint8_t *in_check_mask, int num_bits)
 {
        int retval = ERROR_OK;
        int compare_failed;
@@ -769,9 +780,7 @@ static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 
        if (compare_failed) {
                char *captured_str, *in_check_value_str;
-               int bits = (num_bits > DEBUG_JTAG_IOZ)
-                               ? DEBUG_JTAG_IOZ
-                               : num_bits;
+               int bits = (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits;
 
                /* NOTE:  we've lost diagnostic context here -- 'which tap' */
 
@@ -779,7 +788,7 @@ static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
                in_check_value_str = buf_to_str(in_check_value, bits, 16);
 
                LOG_WARNING("Bad value '%s' captured during DR or IR scan:",
-                               captured_str);
+                       captured_str);
                LOG_WARNING(" check_value: 0x%s", in_check_value_str);
 
                free(captured_str);
@@ -802,8 +811,7 @@ void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *ma
 {
        assert(field->in_value != NULL);
 
-       if (value == NULL)
-       {
+       if (value == NULL) {
                /* no checking to do */
                return;
        }
@@ -814,12 +822,9 @@ void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *ma
        jtag_set_error(retval);
 }
 
-
-
 int default_interface_jtag_execute_queue(void)
 {
-       if (NULL == jtag)
-       {
+       if (NULL == jtag) {
                LOG_ERROR("No JTAG interface configured yet.  "
                        "Issue 'init' command in startup scripts "
                        "before communicating with targets.");
@@ -834,8 +839,7 @@ void jtag_execute_queue_noclear(void)
        jtag_flush_queue_count++;
        jtag_set_error(interface_jtag_execute_queue());
 
-       if (jtag_flush_queue_sleep > 0)
-       {
+       if (jtag_flush_queue_sleep > 0) {
                /* For debug purposes it can be useful to test performance
                 * or behavior when delaying after flushing the queue,
                 * e.g. to simulate long roundtrip times.
@@ -859,8 +863,7 @@ static int jtag_reset_callback(enum jtag_event event, void *priv)
 {
        struct jtag_tap *tap = priv;
 
-       if (event == JTAG_TRST_ASSERTED)
-       {
+       if (event == JTAG_TRST_ASSERTED) {
                tap->enabled = !tap->disabled_after_reset;
 
                /* current instruction is either BYPASS or IDCODE */
@@ -871,16 +874,19 @@ static int jtag_reset_callback(enum jtag_event event, void *priv)
        return ERROR_OK;
 }
 
+/* sleep at least us microseconds. When we sleep more than 1000ms we
+ * do an alive sleep, i.e. keep GDB alive. Note that we could starve
+ * GDB if we slept for <1000ms many times.
+ */
 void jtag_sleep(uint32_t us)
 {
-       alive_sleep(us/1000);
+       if (us < 1000)
+               usleep(us);
+       else
+               alive_sleep((us+999)/1000);
 }
 
-/* Maximum number of enabled JTAG devices we expect in the scan chain,
- * plus one (to detect garbage at the end).  Devices that don't support
- * IDCODE take up fewer bits, possibly allowing a few more devices.
- */
-#define JTAG_MAX_CHAIN_SIZE 20
+#define JTAG_MAX_AUTO_TAPS 20
 
 #define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
 #define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
@@ -889,21 +895,21 @@ void jtag_sleep(uint32_t us)
 /* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
  * know that no valid TAP will have it as an IDCODE value.
  */
-#define END_OF_CHAIN_FLAG      0x000000ff
+#define END_OF_CHAIN_FLAG       0xffffffff
 
 /* a larger IR length than we ever expect to autoprobe */
-#define JTAG_IRLEN_MAX         60
+#define JTAG_IRLEN_MAX          60
 
 static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
 {
        struct scan_field field = {
-                       .num_bits = num_idcode * 32,
-                       .out_value = idcode_buffer,
-                       .in_value = idcode_buffer,
-               };
+               .num_bits = num_idcode * 32,
+               .out_value = idcode_buffer,
+               .in_value = idcode_buffer,
+       };
 
-       // initialize to the end of chain ID value
-       for (unsigned i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
+       /* initialize to the end of chain ID value */
+       for (unsigned i = 0; i < num_idcode; i++)
                buf_set_u32(idcode_buffer, i * 32, 32, END_OF_CHAIN_FLAG);
 
        jtag_add_plain_dr_scan(field.num_bits, field.out_value, field.in_value, TAP_DRPAUSE);
@@ -916,8 +922,7 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
        uint8_t zero_check = 0x0;
        uint8_t one_check = 0xff;
 
-       for (unsigned i = 0; i < count * 4; i++)
-       {
+       for (unsigned i = 0; i < count * 4; i++) {
                zero_check |= idcodes[i];
                one_check &= idcodes[i];
        }
@@ -932,10 +937,9 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
         *     + there are several hundreds of TAPs in bypass, or
         *     + at least a few dozen TAPs all have an all-ones IDCODE
         */
-       if (zero_check == 0x00 || one_check == 0xff)
-       {
+       if (zero_check == 0x00 || one_check == 0xff) {
                LOG_ERROR("JTAG scan chain interrogation failed: all %s",
-                               (zero_check == 0x00) ? "zeroes" : "ones");
+                       (zero_check == 0x00) ? "zeroes" : "ones");
                LOG_ERROR("Check JTAG interface, timings, target power, etc.");
                return false;
        }
@@ -943,26 +947,26 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
 }
 
 static void jtag_examine_chain_display(enum log_levels level, const char *msg,
-               const char *name, uint32_t idcode)
+       const char *name, uint32_t idcode)
 {
-       log_printf_lf(level, __FILE__, __LINE__, __FUNCTION__,
-                                 "JTAG tap: %s %16.16s: 0x%08x "
-                                 "(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
-                                 name, msg,
-                                 (unsigned int)idcode,
-                                 (unsigned int)EXTRACT_MFG(idcode),
-                                 (unsigned int)EXTRACT_PART(idcode),
-                                 (unsigned int)EXTRACT_VER(idcode));
+       log_printf_lf(level, __FILE__, __LINE__, __func__,
+               "JTAG tap: %s %16.16s: 0x%08x "
+               "(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
+               name, msg,
+               (unsigned int)idcode,
+               (unsigned int)EXTRACT_MFG(idcode),
+               (unsigned int)EXTRACT_PART(idcode),
+               (unsigned int)EXTRACT_VER(idcode));
 }
 
 static bool jtag_idcode_is_final(uint32_t idcode)
 {
        /*
         * Some devices, such as AVR8, will output all 1's instead
-        * of TDI input value at end of chain.  Allow those values
+        * of TDI input value at end of chain. Allow those values
         * instead of failing.
         */
-       return idcode == END_OF_CHAIN_FLAG || idcode == 0xFFFFFFFF;
+       return idcode == END_OF_CHAIN_FLAG;
 }
 
 /**
@@ -975,15 +979,14 @@ static bool jtag_idcode_is_final(uint32_t idcode)
 static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned max)
 {
        bool triggered = false;
-       for (; count < max - 31; count += 32)
-       {
+       for (; count < max - 31; count += 32) {
                uint32_t idcode = buf_get_u32(idcodes, count, 32);
 
                /* do not trigger the warning if the data looks good */
                if (jtag_idcode_is_final(idcode))
                        continue;
                LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
-                                       count, (unsigned int)idcode);
+                       count, (unsigned int)idcode);
                triggered = true;
        }
        return triggered;
@@ -991,22 +994,16 @@ static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned ma
 
 static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
 {
-       uint32_t idcode = tap->idcode;
 
-       /* ignore expected BYPASS codes; warn otherwise */
-       if (0 == tap->expected_ids_cnt && !idcode)
+       if (tap->expected_ids_cnt == 0 || !tap->hasidcode)
                return true;
 
-       /* optionally ignore the JTAG version field */
-       uint32_t mask = tap->ignore_version ? ~(0xff << 24) : ~0;
-
-       idcode &= mask;
+       /* optionally ignore the JTAG version field - bits 28-31 of IDCODE */
+       uint32_t mask = tap->ignore_version ? ~(0xf << 28) : ~0;
+       uint32_t idcode = tap->idcode & mask;
 
        /* Loop over the expected identification codes and test for a match */
-       unsigned ii, limit = tap->expected_ids_cnt;
-
-       for (ii = 0; ii < limit; ii++)
-       {
+       for (unsigned ii = 0; ii < tap->expected_ids_cnt; ii++) {
                uint32_t expected = tap->expected_ids[ii] & mask;
 
                if (idcode == expected)
@@ -1019,14 +1016,13 @@ static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
 
        /* If none of the expected ids matched, warn */
        jtag_examine_chain_display(LOG_LVL_WARNING, "UNEXPECTED",
-                       tap->dotted_name, tap->idcode);
-       for (ii = 0; ii < limit; ii++)
-       {
+               tap->dotted_name, tap->idcode);
+       for (unsigned ii = 0; ii < tap->expected_ids_cnt; ii++) {
                char msg[32];
 
-               snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, limit);
+               snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, tap->expected_ids_cnt);
                jtag_examine_chain_display(LOG_LVL_ERROR, msg,
-                               tap->dotted_name, tap->expected_ids[ii]);
+                       tap->dotted_name, tap->expected_ids[ii]);
        }
        return false;
 }
@@ -1036,134 +1032,108 @@ static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
  */
 static int jtag_examine_chain(void)
 {
-       uint8_t idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
-       unsigned bit_count;
        int retval;
-       int tapcount = 0;
-       bool autoprobe = false;
+       unsigned max_taps = jtag_tap_count();
+
+       /* Autoprobe up to this many. */
+       if (max_taps < JTAG_MAX_AUTO_TAPS)
+               max_taps = JTAG_MAX_AUTO_TAPS;
+
+       /* Add room for end-of-chain marker. */
+       max_taps++;
+
+       uint8_t *idcode_buffer = malloc(max_taps * 4);
+       if (idcode_buffer == NULL)
+               return ERROR_JTAG_INIT_FAILED;
 
        /* DR scan to collect BYPASS or IDCODE register contents.
         * Then make sure the scan data has both ones and zeroes.
         */
        LOG_DEBUG("DR scan interrogation for IDCODE/BYPASS");
-       retval = jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
+       retval = jtag_examine_chain_execute(idcode_buffer, max_taps);
        if (retval != ERROR_OK)
-               return retval;
-       if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
-               return ERROR_JTAG_INIT_FAILED;
+               goto out;
+       if (!jtag_examine_chain_check(idcode_buffer, max_taps)) {
+               retval = ERROR_JTAG_INIT_FAILED;
+               goto out;
+       }
 
-       /* point at the 1st tap */
+       /* Point at the 1st predefined tap, if any */
        struct jtag_tap *tap = jtag_tap_next_enabled(NULL);
 
-       if (!tap)
-               autoprobe = true;
-
-       for (bit_count = 0;
-                       tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
-                       tap = jtag_tap_next_enabled(tap))
-       {
+       unsigned bit_count = 0;
+       unsigned autocount = 0;
+       for (unsigned i = 0; i < max_taps; i++) {
+               assert(bit_count < max_taps * 32);
                uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
 
-               if ((idcode & 1) == 0)
-               {
-                       /* Zero for LSB indicates a device in bypass */
-                       LOG_INFO("TAP %s does not have IDCODE",
-                                       tap->dotted_name);
-                       idcode = 0;
-                       tap->hasidcode = false;
-
-                       bit_count += 1;
-               }
-               else
-               {
-                       /* Friendly devices support IDCODE */
-                       tap->hasidcode = true;
-                       jtag_examine_chain_display(LOG_LVL_INFO,
-                                       "tap/device found",
-                                       tap->dotted_name, idcode);
-
-                       bit_count += 32;
-               }
-               tap->idcode = idcode;
-
-               /* ensure the TAP ID matches what was expected */
-               if (!jtag_examine_chain_match_tap(tap))
-                       retval = ERROR_JTAG_INIT_SOFT_FAIL;
-       }
-
-       /* Fail if too many TAPs were enabled for us to verify them all. */
-       if (tap) {
-               LOG_ERROR("Too many TAPs enabled; '%s' ignored.",
-                               tap->dotted_name);
-               return ERROR_JTAG_INIT_FAILED;
-       }
-
-       /* if autoprobing, the tap list is still empty ... populate it! */
-       while (autoprobe && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31) {
-               uint32_t idcode;
-               char buf[12];
-
-               /* Is there another TAP? */
-               idcode = buf_get_u32(idcode_buffer, bit_count, 32);
-               if (jtag_idcode_is_final(idcode))
-                       break;
-
-               /* Default everything in this TAP except IR length.
-                *
-                * REVISIT create a jtag_alloc(chip, tap) routine, and
-                * share it with jim_newtap_cmd().
-                */
-               tap = calloc(1, sizeof *tap);
-               if (!tap)
-                       return ERROR_FAIL;
+               /* No predefined TAP? Auto-probe. */
+               if (tap == NULL) {
+                       /* Is there another TAP? */
+                       if (jtag_idcode_is_final(idcode))
+                               break;
+
+                       /* Default everything in this TAP except IR length.
+                        *
+                        * REVISIT create a jtag_alloc(chip, tap) routine, and
+                        * share it with jim_newtap_cmd().
+                        */
+                       tap = calloc(1, sizeof *tap);
+                       if (!tap) {
+                               retval = ERROR_FAIL;
+                               goto out;
+                       }
 
-               sprintf(buf, "auto%d", tapcount++);
-               tap->chip = strdup(buf);
-               tap->tapname = strdup("tap");
+                       tap->chip = alloc_printf("auto%u", autocount++);
+                       tap->tapname = strdup("tap");
+                       tap->dotted_name = alloc_printf("%s.%s", tap->chip, tap->tapname);
 
-               sprintf(buf, "%s.%s", tap->chip, tap->tapname);
-               tap->dotted_name = strdup(buf);
+                       tap->ir_length = 0; /* ... signifying irlen autoprobe */
+                       tap->ir_capture_mask = 0x03;
+                       tap->ir_capture_value = 0x01;
 
-               /* tap->ir_length == 0 ... signifying irlen autoprobe */
-               tap->ir_capture_mask = 0x03;
-               tap->ir_capture_value = 0x01;
+                       tap->enabled = true;
 
-               tap->enabled = true;
+                       jtag_tap_init(tap);
+               }
 
                if ((idcode & 1) == 0) {
-                       bit_count += 1;
+                       /* Zero for LSB indicates a device in bypass */
+                       LOG_INFO("TAP %s does not have IDCODE", tap->dotted_name);
                        tap->hasidcode = false;
+                       tap->idcode = 0;
+
+                       bit_count += 1;
                } else {
-                       bit_count += 32;
+                       /* Friendly devices support IDCODE */
                        tap->hasidcode = true;
                        tap->idcode = idcode;
+                       jtag_examine_chain_display(LOG_LVL_INFO, "tap/device found", tap->dotted_name, idcode);
 
-                       tap->expected_ids_cnt = 1;
-                       tap->expected_ids = malloc(sizeof(uint32_t));
-                       tap->expected_ids[0] = idcode;
+                       bit_count += 32;
                }
 
-               LOG_WARNING("AUTO %s - use \"jtag newtap "
-                               "%s %s -expected-id 0x%8.8" PRIx32 " ...\"",
-                               tap->dotted_name, tap->chip, tap->tapname,
-                               tap->idcode);
+               /* ensure the TAP ID matches what was expected */
+               if (!jtag_examine_chain_match_tap(tap))
+                       retval = ERROR_JTAG_INIT_SOFT_FAIL;
 
-               jtag_tap_init(tap);
+               tap = jtag_tap_next_enabled(tap);
        }
 
        /* After those IDCODE or BYPASS register values should be
         * only the data we fed into the scan chain.
         */
-       if (jtag_examine_chain_end(idcode_buffer, bit_count,
-                       8 * sizeof(idcode_buffer))) {
-               LOG_ERROR("double-check your JTAG setup (interface, "
-                               "speed, missing TAPs, ...)");
-               return ERROR_JTAG_INIT_FAILED;
+       if (jtag_examine_chain_end(idcode_buffer, bit_count, max_taps * 32)) {
+               LOG_ERROR("double-check your JTAG setup (interface, speed, ...)");
+               retval = ERROR_JTAG_INIT_FAILED;
+               goto out;
        }
 
        /* Return success or, for backwards compatibility if only
         * some IDCODE values mismatched, a soft/continuable fault.
         */
+out:
+       free(idcode_buffer);
        return retval;
 }
 
@@ -1181,7 +1151,7 @@ static int jtag_validate_ircapture(void)
        int total_ir_length = 0;
        uint8_t *ir_test = NULL;
        struct scan_field field;
-       int val;
+       uint64_t val;
        int chain_pos = 0;
        int retval;
 
@@ -1217,17 +1187,16 @@ static int jtag_validate_ircapture(void)
        tap = NULL;
        chain_pos = 0;
 
-       for (;;) {
+       for (;; ) {
                tap = jtag_tap_next_enabled(tap);
-               if (tap == NULL) {
+               if (tap == NULL)
                        break;
-               }
 
                /* If we're autoprobing, guess IR lengths.  They must be at
                 * least two bits.  Guessing will fail if (a) any TAP does
                 * not conform to the JTAG spec; or (b) when the upper bits
                 * captured from some conforming TAP are nonzero.  Or if
-                * (c) an IR length is longer than 32 bits -- which is only
+                * (c) an IR length is longer than JTAG_IRLEN_MAX bits,
                 * an implementation limit, which could someday be raised.
                 *
                 * REVISIT optimization:  if there's a *single* TAP we can
@@ -1241,13 +1210,13 @@ static int jtag_validate_ircapture(void)
                 */
                if (tap->ir_length == 0) {
                        tap->ir_length = 2;
-                       while ((val = buf_get_u32(ir_test, chain_pos,
-                                               tap->ir_length + 1)) == 1
-                                       && tap->ir_length <= 32) {
+                       while ((val = buf_get_u64(ir_test, chain_pos, tap->ir_length + 1)) == 1
+                                       && tap->ir_length < JTAG_IRLEN_MAX) {
                                tap->ir_length++;
                        }
-                       LOG_WARNING("AUTO %s - use \"... -irlen %d\"",
-                                       jtag_tap_name(tap), tap->ir_length);
+                       LOG_WARNING("AUTO %s - use \"jtag newtap " "%s %s -irlen %d "
+                                       "-expected-id 0x%08" PRIx32 "\"",
+                                       tap->dotted_name, tap->chip, tap->tapname, tap->ir_length, tap->idcode);
                }
 
                /* Validate the two LSBs, which must be 01 per JTAG spec.
@@ -1257,31 +1226,28 @@ static int jtag_validate_ircapture(void)
                 * this part of the JTAG spec, so their capture mask/value
                 * attributes might disable this test.
                 */
-               val = buf_get_u32(ir_test, chain_pos, tap->ir_length);
+               val = buf_get_u64(ir_test, chain_pos, tap->ir_length);
                if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
-                       LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x%0*x",
-                                       jtag_tap_name(tap),
-                                       (tap->ir_length + 7) / tap->ir_length,
-                                       val,
-                                       (tap->ir_length + 7) / tap->ir_length,
-                                       (unsigned) tap->ir_capture_value);
+                       LOG_ERROR("%s: IR capture error; saw 0x%0*" PRIx64 " not 0x%0*" PRIx32,
+                               jtag_tap_name(tap),
+                               (tap->ir_length + 7) / tap->ir_length, val,
+                               (tap->ir_length + 7) / tap->ir_length, tap->ir_capture_value);
 
                        retval = ERROR_JTAG_INIT_FAILED;
                        goto done;
                }
-               LOG_DEBUG("%s: IR capture 0x%0*x", jtag_tap_name(tap),
-                               (tap->ir_length + 7) / tap->ir_length, val);
+               LOG_DEBUG("%s: IR capture 0x%0*" PRIx64, jtag_tap_name(tap),
+                       (tap->ir_length + 7) / tap->ir_length, val);
                chain_pos += tap->ir_length;
        }
 
        /* verify the '11' sentinel we wrote is returned at the end */
-       val = buf_get_u32(ir_test, chain_pos, 2);
-       if (val != 0x3)
-       {
+       val = buf_get_u64(ir_test, chain_pos, 2);
+       if (val != 0x3) {
                char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
 
                LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
-                               chain_pos, cbuf);
+                       chain_pos, cbuf);
                free(cbuf);
                retval = ERROR_JTAG_INIT_FAILED;
        }
@@ -1295,7 +1261,6 @@ done:
        return retval;
 }
 
-
 void jtag_tap_init(struct jtag_tap *tap)
 {
        unsigned ir_len_bits;
@@ -1309,38 +1274,39 @@ void jtag_tap_init(struct jtag_tap *tap)
        tap->expected_mask = calloc(1, ir_len_bytes);
        tap->cur_instr = malloc(ir_len_bytes);
 
-       /// @todo cope better with ir_length bigger than 32 bits
+       /** @todo cope better with ir_length bigger than 32 bits */
        if (ir_len_bits > 32)
                ir_len_bits = 32;
 
        buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
        buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
 
-       // TAP will be in bypass mode after jtag_validate_ircapture()
+       /* TAP will be in bypass mode after jtag_validate_ircapture() */
        tap->bypass = 1;
        buf_set_ones(tap->cur_instr, tap->ir_length);
 
-       // register the reset callback for the TAP
+       /* register the reset callback for the TAP */
        jtag_register_event_callback(&jtag_reset_callback, tap);
+       jtag_tap_add(tap);
 
        LOG_DEBUG("Created Tap: %s @ abs position %d, "
                        "irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
-                               tap->abs_chain_position, tap->ir_length,
-                               (unsigned) tap->ir_capture_value,
-                               (unsigned) tap->ir_capture_mask);
-       jtag_tap_add(tap);
+                       tap->abs_chain_position, tap->ir_length,
+                       (unsigned) tap->ir_capture_value,
+                       (unsigned) tap->ir_capture_mask);
 }
 
 void jtag_tap_free(struct jtag_tap *tap)
 {
        jtag_unregister_event_callback(&jtag_reset_callback, tap);
 
-       /// @todo is anything missing? no memory leaks please
-       free((void *)tap->expected);
-       free((void *)tap->expected_ids);
-       free((void *)tap->chip);
-       free((void *)tap->tapname);
-       free((void *)tap->dotted_name);
+       free(tap->expected);
+       free(tap->expected_mask);
+       free(tap->expected_ids);
+       free(tap->cur_instr);
+       free(tap->chip);
+       free(tap->tapname);
+       free(tap->dotted_name);
        free(tap);
 }
 
@@ -1353,20 +1319,18 @@ int adapter_init(struct command_context *cmd_ctx)
        if (jtag)
                return ERROR_OK;
 
-       if (!jtag_interface)
-       {
+       if (!jtag_interface) {
                /* nothing was previously specified by "interface" command */
                LOG_ERROR("Debug Adapter has to be specified, "
                        "see \"interface\" command");
                return ERROR_JTAG_INVALID_INTERFACE;
        }
 
+       int retval;
+       retval = jtag_interface->init();
+       if (retval != ERROR_OK)
+               return retval;
        jtag = jtag_interface;
-       if (jtag_interface->init() != ERROR_OK)
-       {
-               jtag = NULL;
-               return ERROR_JTAG_INIT_FAILED;
-       }
 
        /* LEGACY SUPPORT ... adapter drivers  must declare what
         * transports they allow.  Until they all do so, assume
@@ -1376,33 +1340,43 @@ int adapter_init(struct command_context *cmd_ctx)
                LOG_ERROR("Adapter driver '%s' did not declare "
                        "which transports it allows; assuming "
                        "JTAG-only", jtag->name);
-               int retval = allow_transports(cmd_ctx, jtag_only);
+               retval = allow_transports(cmd_ctx, jtag_only);
                if (retval != ERROR_OK)
                        return retval;
        }
 
+       if (jtag->speed == NULL) {
+               LOG_INFO("This adapter doesn't support configurable speed");
+               return ERROR_OK;
+       }
+
+       if (CLOCK_MODE_UNSELECTED == clock_mode) {
+               LOG_ERROR("An adapter speed is not selected in the init script."
+                       " Insert a call to adapter_khz or jtag_rclk to proceed.");
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
        int requested_khz = jtag_get_speed_khz();
        int actual_khz = requested_khz;
-       int jtag_speed_var;
-       int retval = jtag_get_speed(&jtag_speed_var);
+       int jtag_speed_var = 0;
+       retval = jtag_get_speed(&jtag_speed_var);
+       if (retval != ERROR_OK)
+               return retval;
+       retval = jtag->speed(jtag_speed_var);
        if (retval != ERROR_OK)
                return retval;
        retval = jtag_get_speed_readable(&actual_khz);
        if (ERROR_OK != retval)
                LOG_INFO("adapter-specific clock speed value %d", jtag_speed_var);
-       else if (actual_khz)
-       {
+       else if (actual_khz) {
                /* Adaptive clocking -- JTAG-specific */
                if ((CLOCK_MODE_RCLK == clock_mode)
-                       || ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz))
-               {
+                               || ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz)) {
                        LOG_INFO("RCLK (adaptive clock speed) not supported - fallback to %d kHz"
-                               , actual_khz);
-               }
-               else
+                       , actual_khz);
+               } else
                        LOG_INFO("clock speed %d kHz", actual_khz);
-       }
-       else
+       } else
                LOG_INFO("RCLK (adaptive clock speed)");
 
        return ERROR_OK;
@@ -1430,13 +1404,14 @@ int jtag_init_inner(struct command_context *cmd_ctx)
                 * the TAP's IDCODE values.
                 */
                LOG_WARNING("There are no enabled taps.  "
-                               "AUTO PROBING MIGHT NOT WORK!!");
+                       "AUTO PROBING MIGHT NOT WORK!!");
 
                /* REVISIT default clock will often be too fast ... */
        }
 
        jtag_add_tlr();
-       if ((retval = jtag_execute_queue()) != ERROR_OK)
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
                return retval;
 
        /* Examine DR values first.  This discovers problems which will
@@ -1445,22 +1420,22 @@ int jtag_init_inner(struct command_context *cmd_ctx)
         */
        retval = jtag_examine_chain();
        switch (retval) {
-       case ERROR_OK:
-               /* complete success */
-               break;
-       default:
-               /* For backward compatibility reasons, try coping with
-                * configuration errors involving only ID mismatches.
-                * We might be able to talk to the devices.
-                *
-                * Also the device might be powered down during startup.
-                *
-                * After OpenOCD starts, we can try to power on the device
-                * and run a reset.
-                */
-               LOG_ERROR("Trying to use configured scan chain anyway...");
-               issue_setup = false;
-               break;
+               case ERROR_OK:
+                       /* complete success */
+                       break;
+               default:
+                       /* For backward compatibility reasons, try coping with
+                        * configuration errors involving only ID mismatches.
+                        * We might be able to talk to the devices.
+                        *
+                        * Also the device might be powered down during startup.
+                        *
+                        * After OpenOCD starts, we can try to power on the device
+                        * and run a reset.
+                        */
+                       LOG_ERROR("Trying to use configured scan chain anyway...");
+                       issue_setup = false;
+                       break;
        }
 
        /* Now look at IR values.  Problems here will prevent real
@@ -1470,8 +1445,7 @@ int jtag_init_inner(struct command_context *cmd_ctx)
         * ircapture/irmask values during TAP setup.)
         */
        retval = jtag_validate_ircapture();
-       if (retval != ERROR_OK)
-       {
+       if (retval != ERROR_OK) {
                /* The target might be powered down. The user
                 * can power it up and reset it after firing
                 * up OpenOCD.
@@ -1493,7 +1467,7 @@ int adapter_quit(void)
        if (!jtag || !jtag->quit)
                return ERROR_OK;
 
-       // close the JTAG interface
+       /* close the JTAG interface */
        int result = jtag->quit();
        if (ERROR_OK != result)
                LOG_ERROR("failed: %d", result);
@@ -1501,12 +1475,25 @@ int adapter_quit(void)
        return ERROR_OK;
 }
 
+int swd_init_reset(struct command_context *cmd_ctx)
+{
+       int retval = adapter_init(cmd_ctx);
+       if (retval != ERROR_OK)
+               return retval;
+
+       LOG_DEBUG("Initializing with hard SRST reset");
+
+       if (jtag_reset_config & RESET_HAS_SRST)
+               swd_add_reset(1);
+       swd_add_reset(0);
+       retval = jtag_execute_queue();
+       return retval;
+}
 
 int jtag_init_reset(struct command_context *cmd_ctx)
 {
-       int retval;
-
-       if ((retval = adapter_init(cmd_ctx)) != ERROR_OK)
+       int retval = adapter_init(cmd_ctx);
+       if (retval != ERROR_OK)
                return retval;
 
        LOG_DEBUG("Initializing with hard TRST+SRST reset");
@@ -1535,15 +1522,26 @@ int jtag_init_reset(struct command_context *cmd_ctx)
         * REVISIT once Tcl code can read the reset_config modes, this won't
         * need to be a C routine at all...
         */
-       jtag_add_reset(1, 0); /* TAP_RESET, using TMS+TCK or TRST */
-       if (jtag_reset_config & RESET_HAS_SRST)
-       {
+       if (jtag_reset_config & RESET_HAS_SRST) {
                jtag_add_reset(1, 1);
                if ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0)
                        jtag_add_reset(0, 1);
+       } else {
+               jtag_add_reset(1, 0);   /* TAP_RESET, using TMS+TCK or TRST */
        }
-       jtag_add_reset(0, 0);
-       if ((retval = jtag_execute_queue()) != ERROR_OK)
+
+       /* some targets enable us to connect with srst asserted */
+       if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+               if (jtag_reset_config & RESET_SRST_NO_GATING)
+                       jtag_add_reset(0, 1);
+               else {
+                       LOG_WARNING("\'srst_nogate\' reset_config option is required");
+                       jtag_add_reset(0, 0);
+               }
+       } else
+               jtag_add_reset(0, 0);
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
                return retval;
 
        /* Check that we can communication on the JTAG chain + eventually we want to
@@ -1558,14 +1556,22 @@ int jtag_init_reset(struct command_context *cmd_ctx)
 
 int jtag_init(struct command_context *cmd_ctx)
 {
-       int retval;
-
-       if ((retval = adapter_init(cmd_ctx)) != ERROR_OK)
+       int retval = adapter_init(cmd_ctx);
+       if (retval != ERROR_OK)
                return retval;
 
        /* guard against oddball hardware: force resets to be inactive */
        jtag_add_reset(0, 0);
-       if ((retval = jtag_execute_queue()) != ERROR_OK)
+
+       /* some targets enable us to connect with srst asserted */
+       if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+               if (jtag_reset_config & RESET_SRST_NO_GATING)
+                       jtag_add_reset(0, 1);
+               else
+                       LOG_WARNING("\'srst_nogate\' reset_config option is required");
+       }
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
                return retval;
 
        if (Jim_Eval_Named(cmd_ctx->interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
@@ -1579,29 +1585,25 @@ unsigned jtag_get_speed_khz(void)
        return speed_khz;
 }
 
-static int adapter_khz_to_speed(unsigned khz, intspeed)
+static int adapter_khz_to_speed(unsigned khz, int *speed)
 {
        LOG_DEBUG("convert khz to interface specific speed value");
        speed_khz = khz;
-       if (jtag != NULL)
-       {
+       if (jtag != NULL) {
                LOG_DEBUG("have interface set up");
                int speed_div1;
                int retval = jtag->khz(jtag_get_speed_khz(), &speed_div1);
                if (ERROR_OK != retval)
-               {
                        return retval;
-               }
                *speed = speed_div1;
        }
        return ERROR_OK;
 }
 
-static int jtag_rclk_to_speed(unsigned fallback_speed_khz, intspeed)
+static int jtag_rclk_to_speed(unsigned fallback_speed_khz, int *speed)
 {
        int retval = adapter_khz_to_speed(0, speed);
-       if ((ERROR_OK != retval) && fallback_speed_khz)
-       {
+       if ((ERROR_OK != retval) && fallback_speed_khz) {
                LOG_DEBUG("trying fallback speed...");
                retval = adapter_khz_to_speed(fallback_speed_khz, speed);
        }
@@ -1637,11 +1639,7 @@ int jtag_config_rclk(unsigned fallback_speed_khz)
 
 int jtag_get_speed(int *speed)
 {
-       switch(clock_mode)
-       {
-               case CLOCK_MODE_SPEED:
-                       *speed = jtag_speed;
-                       break;
+       switch (clock_mode) {
                case CLOCK_MODE_KHZ:
                        adapter_khz_to_speed(jtag_get_speed_khz(), speed);
                        break;
@@ -1657,7 +1655,7 @@ int jtag_get_speed(int *speed)
 
 int jtag_get_speed_readable(int *khz)
 {
-       int jtag_speed_var;
+       int jtag_speed_var = 0;
        int retval = jtag_get_speed(&jtag_speed_var);
        if (retval != ERROR_OK)
                return retval;
@@ -1686,8 +1684,7 @@ bool jtag_will_verify_capture_ir()
 
 int jtag_power_dropout(int *dropout)
 {
-       if (jtag == NULL)
-       {
+       if (jtag == NULL) {
                /* TODO: as the jtag interface is not valid all
                 * we can do at the moment is exit OpenOCD */
                LOG_ERROR("No Valid JTAG Interface Configured.");
@@ -1794,3 +1791,54 @@ bool transport_is_jtag(void)
 {
        return get_current_transport() == &jtag_transport;
 }
+
+void adapter_assert_reset(void)
+{
+       if (transport_is_jtag()) {
+               if (jtag_reset_config & RESET_SRST_PULLS_TRST)
+                       jtag_add_reset(1, 1);
+               else
+                       jtag_add_reset(0, 1);
+       } else if (transport_is_swd())
+               swd_add_reset(1);
+       else if (get_current_transport() != NULL)
+               LOG_ERROR("reset is not supported on %s",
+                       get_current_transport()->name);
+       else
+               LOG_ERROR("transport is not selected");
+}
+
+void adapter_deassert_reset(void)
+{
+       if (transport_is_jtag())
+               jtag_add_reset(0, 0);
+       else if (transport_is_swd())
+               swd_add_reset(0);
+       else if (get_current_transport() != NULL)
+               LOG_ERROR("reset is not supported on %s",
+                       get_current_transport()->name);
+       else
+               LOG_ERROR("transport is not selected");
+}
+
+int adapter_config_trace(bool enabled, enum tpio_pin_protocol pin_protocol,
+                        uint32_t port_size, unsigned int *trace_freq)
+{
+       if (jtag->config_trace)
+               return jtag->config_trace(enabled, pin_protocol, port_size,
+                                         trace_freq);
+       else if (enabled) {
+               LOG_ERROR("The selected interface does not support tracing");
+               return ERROR_FAIL;
+       }
+
+       return ERROR_OK;
+}
+
+int adapter_poll_trace(uint8_t *buf, size_t *size)
+{
+       if (jtag->poll_trace)
+               return jtag->poll_trace(buf, size);
+
+       return ERROR_FAIL;
+}