jtag_libusb_bulk_read|write: return error code instead of size
[fw/openocd] / src / jtag / drivers / stlink_usb.c
index 5e0411ff609dc3c2d4949ef1cbacdd9cc21f8823..8e4493ed89560e245fcee61ec504beca77ac0628 100644 (file)
 
 /* project specific includes */
 #include <helper/binarybuffer.h>
+#include <helper/bits.h>
 #include <jtag/interface.h>
 #include <jtag/hla/hla_layout.h>
 #include <jtag/hla/hla_transport.h>
 #include <jtag/hla/hla_interface.h>
 #include <target/target.h>
+#include <transport/transport.h>
 
 #include <target/cortex_m.h>
 
 #include "libusb_common.h"
 
+#ifdef HAVE_LIBUSB1
+#define USE_LIBUSB_ASYNCIO
+#endif
+
 #define ENDPOINT_IN  0x80
 #define ENDPOINT_OUT 0x00
 
 #define STLINK_V2_PID         (0x3748)
 #define STLINK_V2_1_PID       (0x374B)
 #define STLINK_V2_1_NO_MSD_PID  (0x3752)
+#define STLINK_V3_USBLOADER_PID (0x374D)
+#define STLINK_V3E_PID          (0x374E)
+#define STLINK_V3S_PID          (0x374F)
+#define STLINK_V3_2VCP_PID      (0x3753)
 
-/* the current implementation of the stlink limits
- * 8bit read/writes to max 64 bytes. */
+/*
+ * ST-Link/V1, ST-Link/V2 and ST-Link/V2.1 are full-speed USB devices and
+ * this limits the bulk packet size and the 8bit read/writes to max 64 bytes.
+ * STLINK-V3 is a high speed USB 2.0 and the limit is 512 bytes.
+ */
 #define STLINK_MAX_RW8         (64)
+#define STLINKV3_MAX_RW8       (512)
 
 /* "WAIT" responses will be retried (with exponential backoff) at
  * most this many times before failing to caller.
@@ -77,6 +91,7 @@
 enum stlink_jtag_api_version {
        STLINK_JTAG_API_V1 = 1,
        STLINK_JTAG_API_V2,
+       STLINK_JTAG_API_V3,
 };
 
 /** */
@@ -87,8 +102,8 @@ struct stlink_usb_version {
        int jtag;
        /** */
        int swim;
-       /** highest supported jtag api version */
-       enum stlink_jtag_api_version jtag_api_max;
+       /** jtag api version supported */
+       enum stlink_jtag_api_version jtag_api;
        /** one bit for each feature supported. See macros STLINK_F_* */
        uint32_t flags;
 };
@@ -123,8 +138,6 @@ struct stlink_usb_handle_s {
        uint16_t vid;
        /** */
        uint16_t pid;
-       /** this is the currently used jtag api */
-       enum stlink_jtag_api_version jtag_api;
        /** */
        struct {
                /** whether SWO tracing is enabled or not */
@@ -145,6 +158,7 @@ struct stlink_usb_handle_s {
 #define STLINK_SWD_AP_FAULT            0x11
 #define STLINK_SWD_AP_ERROR            0x12
 #define STLINK_SWD_AP_PARITY_ERROR     0x13
+#define STLINK_JTAG_GET_IDCODE_ERROR   0x09
 #define STLINK_JTAG_WRITE_ERROR        0x0c
 #define STLINK_JTAG_WRITE_VERIF_ERROR  0x0d
 #define STLINK_SWD_DP_WAIT             0x14
@@ -156,6 +170,8 @@ struct stlink_usb_handle_s {
 #define STLINK_SWD_AP_STICKY_ERROR     0x19
 #define STLINK_SWD_AP_STICKYORUN_ERROR 0x1a
 
+#define STLINK_BAD_AP_ERROR            0x1d
+
 #define STLINK_CORE_RUNNING            0x80
 #define STLINK_CORE_HALTED             0x81
 #define STLINK_CORE_STAT_UNKNOWN       -1
@@ -207,7 +223,6 @@ struct stlink_usb_handle_s {
 #define STLINK_SWIM_READMEM                0x0b
 #define STLINK_SWIM_READBUF                0x0c
 
-#define STLINK_DEBUG_ENTER_JTAG            0x00
 #define STLINK_DEBUG_GETSTATUS             0x01
 #define STLINK_DEBUG_FORCEDEBUG            0x02
 #define STLINK_DEBUG_APIV1_RESETSYS        0x03
@@ -225,8 +240,9 @@ struct stlink_usb_handle_s {
 #define STLINK_DEBUG_APIV1_WRITEDEBUGREG   0x0f
 #define STLINK_DEBUG_APIV1_SETWATCHPOINT   0x10
 
-#define STLINK_DEBUG_ENTER_JTAG            0x00
-#define STLINK_DEBUG_ENTER_SWD             0xa3
+#define STLINK_DEBUG_ENTER_JTAG_RESET      0x00
+#define STLINK_DEBUG_ENTER_SWD_NO_RESET    0xa3
+#define STLINK_DEBUG_ENTER_JTAG_NO_RESET   0xa4
 
 #define STLINK_DEBUG_APIV1_ENTER           0x20
 #define STLINK_DEBUG_EXIT                  0x21
@@ -244,22 +260,37 @@ struct stlink_usb_handle_s {
 #define STLINK_DEBUG_APIV2_GETLASTRWSTATUS 0x3B
 #define STLINK_DEBUG_APIV2_DRIVE_NRST      0x3C
 
+#define STLINK_DEBUG_APIV2_GETLASTRWSTATUS2 0x3E
+
 #define STLINK_DEBUG_APIV2_START_TRACE_RX  0x40
 #define STLINK_DEBUG_APIV2_STOP_TRACE_RX   0x41
 #define STLINK_DEBUG_APIV2_GET_TRACE_NB    0x42
 #define STLINK_DEBUG_APIV2_SWD_SET_FREQ    0x43
 #define STLINK_DEBUG_APIV2_JTAG_SET_FREQ   0x44
-
+#define STLINK_DEBUG_APIV2_READ_DAP_REG    0x45
+#define STLINK_DEBUG_APIV2_WRITE_DAP_REG   0x46
 #define STLINK_DEBUG_APIV2_READMEM_16BIT   0x47
 #define STLINK_DEBUG_APIV2_WRITEMEM_16BIT  0x48
 
+#define STLINK_DEBUG_APIV2_INIT_AP         0x4B
+#define STLINK_DEBUG_APIV2_CLOSE_AP_DBG    0x4C
+
+#define STLINK_APIV3_SET_COM_FREQ           0x61
+#define STLINK_APIV3_GET_COM_FREQ           0x62
+
+#define STLINK_APIV3_GET_VERSION_EX         0xFB
+
 #define STLINK_DEBUG_APIV2_DRIVE_NRST_LOW   0x00
 #define STLINK_DEBUG_APIV2_DRIVE_NRST_HIGH  0x01
 #define STLINK_DEBUG_APIV2_DRIVE_NRST_PULSE 0x02
 
+#define STLINK_DEBUG_PORT_ACCESS            0xffff
+
 #define STLINK_TRACE_SIZE               4096
 #define STLINK_TRACE_MAX_HZ             2000000
 
+#define STLINK_V3_MAX_FREQ_NB               10
+
 /** */
 enum stlink_mode {
        STLINK_MODE_UNKNOWN = 0,
@@ -277,10 +308,15 @@ enum stlink_mode {
  * Map the relevant features, quirks and workaround for specific firmware
  * version of stlink
  */
-#define STLINK_F_HAS_TRACE              (1UL << 0)
-#define STLINK_F_HAS_SWD_SET_FREQ       (1UL << 1)
-#define STLINK_F_HAS_JTAG_SET_FREQ      (1UL << 2)
-#define STLINK_F_HAS_MEM_16BIT          (1UL << 3)
+#define STLINK_F_HAS_TRACE              BIT(0)
+#define STLINK_F_HAS_SWD_SET_FREQ       BIT(1)
+#define STLINK_F_HAS_JTAG_SET_FREQ      BIT(2)
+#define STLINK_F_HAS_MEM_16BIT          BIT(3)
+#define STLINK_F_HAS_GETLASTRWSTATUS2   BIT(4)
+#define STLINK_F_HAS_DAP_REG            BIT(5)
+#define STLINK_F_QUIRK_JTAG_DP_READ     BIT(6)
+#define STLINK_F_HAS_AP_INIT            BIT(7)
+#define STLINK_F_HAS_DPBANKSEL          BIT(8)
 
 /* aliases */
 #define STLINK_F_HAS_TARGET_VOLT        STLINK_F_HAS_TRACE
@@ -320,19 +356,191 @@ static const struct speed_map stlink_khz_to_speed_map_jtag[] = {
 
 static void stlink_usb_init_buffer(void *handle, uint8_t direction, uint32_t size);
 static int stlink_swim_status(void *handle);
+void stlink_dump_speed_map(const struct speed_map *map, unsigned int map_size);
+static int stlink_get_com_freq(void *handle, bool is_jtag, struct speed_map *map);
+static int stlink_speed(void *handle, int khz, bool query);
+
+/** */
+static unsigned int stlink_usb_block(void *handle)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (h->version.stlink == 3)
+               return STLINKV3_MAX_RW8;
+       else
+               return STLINK_MAX_RW8;
+}
+
+
+
+#ifdef USE_LIBUSB_ASYNCIO
+
+static LIBUSB_CALL void sync_transfer_cb(struct libusb_transfer *transfer)
+{
+       int *completed = transfer->user_data;
+       *completed = 1;
+       /* caller interprets result and frees transfer */
+}
+
+
+static void sync_transfer_wait_for_completion(struct libusb_transfer *transfer)
+{
+       int r, *completed = transfer->user_data;
+
+       /* Assuming a single libusb context exists.  There no existing interface into this
+        * module to pass a libusb context.
+        */
+       struct libusb_context *ctx = NULL;
+
+       while (!*completed) {
+               r = libusb_handle_events_completed(ctx, completed);
+               if (r < 0) {
+                       if (r == LIBUSB_ERROR_INTERRUPTED)
+                               continue;
+                       libusb_cancel_transfer(transfer);
+                       continue;
+               }
+       }
+}
+
+
+static int transfer_error_status(const struct libusb_transfer *transfer)
+{
+       int r = 0;
+
+       switch (transfer->status) {
+               case LIBUSB_TRANSFER_COMPLETED:
+                       r = 0;
+                       break;
+               case LIBUSB_TRANSFER_TIMED_OUT:
+                       r = LIBUSB_ERROR_TIMEOUT;
+                       break;
+               case LIBUSB_TRANSFER_STALL:
+                       r = LIBUSB_ERROR_PIPE;
+                       break;
+               case LIBUSB_TRANSFER_OVERFLOW:
+                       r = LIBUSB_ERROR_OVERFLOW;
+                       break;
+               case LIBUSB_TRANSFER_NO_DEVICE:
+                       r = LIBUSB_ERROR_NO_DEVICE;
+                       break;
+               case LIBUSB_TRANSFER_ERROR:
+               case LIBUSB_TRANSFER_CANCELLED:
+                       r = LIBUSB_ERROR_IO;
+                       break;
+               default:
+                       r = LIBUSB_ERROR_OTHER;
+                       break;
+       }
+
+       return r;
+}
+
+struct jtag_xfer {
+       int ep;
+       uint8_t *buf;
+       size_t size;
+       /* Internal */
+       int retval;
+       int completed;
+       size_t transfer_size;
+       struct libusb_transfer *transfer;
+};
+
+static int jtag_libusb_bulk_transfer_n(
+               jtag_libusb_device_handle * dev_handle,
+               struct jtag_xfer *transfers,
+               size_t n_transfers,
+               int timeout)
+{
+       int retval = 0;
+       int returnval = ERROR_OK;
+
+
+       for (size_t i = 0; i < n_transfers; ++i) {
+               transfers[i].retval = 0;
+               transfers[i].completed = 0;
+               transfers[i].transfer_size = 0;
+               transfers[i].transfer = libusb_alloc_transfer(0);
+
+               if (transfers[i].transfer == NULL) {
+                       for (size_t j = 0; j < i; ++j)
+                               libusb_free_transfer(transfers[j].transfer);
+
+                       LOG_DEBUG("ERROR, failed to alloc usb transfers");
+                       for (size_t k = 0; k < n_transfers; ++k)
+                               transfers[k].retval = LIBUSB_ERROR_NO_MEM;
+                       return ERROR_FAIL;
+               }
+       }
+
+       for (size_t i = 0; i < n_transfers; ++i) {
+               libusb_fill_bulk_transfer(
+                               transfers[i].transfer,
+                               dev_handle,
+                               transfers[i].ep, transfers[i].buf, transfers[i].size,
+                               sync_transfer_cb, &transfers[i].completed, timeout);
+               transfers[i].transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
+
+               retval = libusb_submit_transfer(transfers[i].transfer);
+               if (retval < 0) {
+                       LOG_DEBUG("ERROR, failed to submit transfer %zu, error %d", i, retval);
+
+                       /* Probably no point continuing to submit transfers once a submission fails.
+                        * As a result, tag all remaining transfers as errors.
+                        */
+                       for (size_t j = i; j < n_transfers; ++j)
+                               transfers[j].retval = retval;
+
+                       returnval = ERROR_FAIL;
+                       break;
+               }
+       }
+
+       /* Wait for every submitted USB transfer to complete.
+       */
+       for (size_t i = 0; i < n_transfers; ++i) {
+               if (transfers[i].retval == 0) {
+                       sync_transfer_wait_for_completion(transfers[i].transfer);
+
+                       retval = transfer_error_status(transfers[i].transfer);
+                       if (retval) {
+                               returnval = ERROR_FAIL;
+                               transfers[i].retval = retval;
+                               LOG_DEBUG("ERROR, transfer %zu failed, error %d", i, retval);
+                       } else {
+                               /* Assuming actual_length is only valid if there is no transfer error.
+                                */
+                               transfers[i].transfer_size = transfers[i].transfer->actual_length;
+                       }
+               }
+
+               libusb_free_transfer(transfers[i].transfer);
+               transfers[i].transfer = NULL;
+       }
+
+       return returnval;
+}
+
+#endif
+
 
 /** */
 static int stlink_usb_xfer_v1_get_status(void *handle)
 {
        struct stlink_usb_handle_s *h = handle;
+       int tr, ret;
 
        assert(handle != NULL);
 
        /* read status */
        memset(h->cmdbuf, 0, STLINK_SG_SIZE);
 
-       if (jtag_libusb_bulk_read(h->fd, h->rx_ep, (char *)h->cmdbuf,
-                       13, STLINK_READ_TIMEOUT) != 13)
+       ret = jtag_libusb_bulk_read(h->fd, h->rx_ep, (char *)h->cmdbuf, 13,
+                                   STLINK_READ_TIMEOUT, &tr);
+       if (ret || tr != 13)
                return ERROR_FAIL;
 
        uint32_t t1;
@@ -354,27 +562,68 @@ static int stlink_usb_xfer_v1_get_status(void *handle)
        return ERROR_OK;
 }
 
-/** */
+#ifdef USE_LIBUSB_ASYNCIO
 static int stlink_usb_xfer_rw(void *handle, int cmdsize, const uint8_t *buf, int size)
 {
        struct stlink_usb_handle_s *h = handle;
 
        assert(handle != NULL);
 
-       if (jtag_libusb_bulk_write(h->fd, h->tx_ep, (char *)h->cmdbuf, cmdsize,
-                       STLINK_WRITE_TIMEOUT) != cmdsize) {
-               return ERROR_FAIL;
+       size_t n_transfers = 0;
+       struct jtag_xfer transfers[2];
+
+       memset(transfers, 0, sizeof(transfers));
+
+       transfers[0].ep = h->tx_ep;
+       transfers[0].buf = h->cmdbuf;
+       transfers[0].size = cmdsize;
+
+       ++n_transfers;
+
+       if (h->direction == h->tx_ep && size) {
+               transfers[1].ep = h->tx_ep;
+               transfers[1].buf = (uint8_t *)buf;
+               transfers[1].size = size;
+
+               ++n_transfers;
+       } else if (h->direction == h->rx_ep && size) {
+               transfers[1].ep = h->rx_ep;
+               transfers[1].buf = (uint8_t *)buf;
+               transfers[1].size = size;
+
+               ++n_transfers;
        }
 
+       return jtag_libusb_bulk_transfer_n(
+                       h->fd,
+                       transfers,
+                       n_transfers,
+                       STLINK_WRITE_TIMEOUT);
+}
+#else
+static int stlink_usb_xfer_rw(void *handle, int cmdsize, const uint8_t *buf, int size)
+{
+       struct stlink_usb_handle_s *h = handle;
+       int tr, ret;
+
+       assert(handle != NULL);
+
+       ret = jtag_libusb_bulk_write(h->fd, h->tx_ep, (char *)h->cmdbuf,
+                                    cmdsize, STLINK_WRITE_TIMEOUT, &tr);
+       if (ret || tr != cmdsize)
+               return ERROR_FAIL;
+
        if (h->direction == h->tx_ep && size) {
-               if (jtag_libusb_bulk_write(h->fd, h->tx_ep, (char *)buf,
-                               size, STLINK_WRITE_TIMEOUT) != size) {
+               ret = jtag_libusb_bulk_write(h->fd, h->tx_ep, (char *)buf,
+                                            size, STLINK_WRITE_TIMEOUT, &tr);
+               if (ret || tr != size) {
                        LOG_DEBUG("bulk write failed");
                        return ERROR_FAIL;
                }
        } else if (h->direction == h->rx_ep && size) {
-               if (jtag_libusb_bulk_read(h->fd, h->rx_ep, (char *)buf,
-                               size, STLINK_READ_TIMEOUT) != size) {
+               ret = jtag_libusb_bulk_read(h->fd, h->rx_ep, (char *)buf,
+                                           size, STLINK_READ_TIMEOUT, &tr);
+               if (ret || tr != size) {
                        LOG_DEBUG("bulk read failed");
                        return ERROR_FAIL;
                }
@@ -382,6 +631,7 @@ static int stlink_usb_xfer_rw(void *handle, int cmdsize, const uint8_t *buf, int
 
        return ERROR_OK;
 }
+#endif
 
 /** */
 static int stlink_usb_xfer_v1_get_sense(void *handle)
@@ -414,8 +664,9 @@ static int stlink_usb_xfer_v1_get_sense(void *handle)
        transfers block in cmdbuf
        <size> indicates number of bytes in the following
        data phase.
+       Ignore the (eventual) error code in the received packet.
 */
-static int stlink_usb_xfer(void *handle, const uint8_t *buf, int size)
+static int stlink_usb_xfer_noerrcheck(void *handle, const uint8_t *buf, int size)
 {
        int err, cmdsize = STLINK_CMD_SIZE_V2;
        struct stlink_usb_handle_s *h = handle;
@@ -471,7 +722,7 @@ static int stlink_usb_error_check(void *handle)
        }
 
        /* TODO: no error checking yet on api V1 */
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                h->databuf[0] = STLINK_DEBUG_ERR_OK;
 
        switch (h->databuf[0]) {
@@ -486,6 +737,9 @@ static int stlink_usb_error_check(void *handle)
                case STLINK_SWD_DP_WAIT:
                        LOG_DEBUG("wait status SWD_DP_WAIT (0x%x)", STLINK_SWD_DP_WAIT);
                        return ERROR_WAIT;
+               case STLINK_JTAG_GET_IDCODE_ERROR:
+                       LOG_DEBUG("STLINK_JTAG_GET_IDCODE_ERROR");
+                       return ERROR_FAIL;
                case STLINK_JTAG_WRITE_ERROR:
                        LOG_DEBUG("Write error");
                        return ERROR_FAIL;
@@ -524,12 +778,31 @@ static int stlink_usb_error_check(void *handle)
                case STLINK_SWD_AP_STICKYORUN_ERROR:
                        LOG_DEBUG("STLINK_SWD_AP_STICKYORUN_ERROR");
                        return ERROR_FAIL;
+               case STLINK_BAD_AP_ERROR:
+                       LOG_DEBUG("STLINK_BAD_AP_ERROR");
+                       return ERROR_FAIL;
                default:
                        LOG_DEBUG("unknown/unexpected STLINK status code 0x%x", h->databuf[0]);
                        return ERROR_FAIL;
        }
 }
 
+/*
+ * Wrapper around stlink_usb_xfer_noerrcheck()
+ * to check the error code in the received packet
+ */
+static int stlink_usb_xfer_errcheck(void *handle, const uint8_t *buf, int size)
+{
+       int retval;
+
+       assert(size > 0);
+
+       retval = stlink_usb_xfer_noerrcheck(handle, buf, size);
+       if (retval != ERROR_OK)
+               return retval;
+
+       return stlink_usb_error_check(handle);
+}
 
 /** Issue an STLINK command via USB transfer, with retries on any wait status responses.
 
@@ -546,7 +819,7 @@ static int stlink_cmd_allow_retry(void *handle, const uint8_t *buf, int size)
 
        while (1) {
                if ((h->transport != HL_TRANSPORT_SWIM) || !retries) {
-                       res = stlink_usb_xfer(handle, buf, size);
+                       res = stlink_usb_xfer_noerrcheck(handle, buf, size);
                        if (res != ERROR_OK)
                                return res;
                }
@@ -559,7 +832,9 @@ static int stlink_cmd_allow_retry(void *handle, const uint8_t *buf, int size)
 
                res = stlink_usb_error_check(handle);
                if (res == ERROR_WAIT && retries < MAX_WAIT_RETRIES) {
-                       usleep((1<<retries++) * 1000);
+                       useconds_t delay_us = (1<<retries++) * 1000;
+                       LOG_DEBUG("stlink_cmd_allow_retry ERROR_WAIT, retry %d, delaying %u microseconds", retries, delay_us);
+                       usleep(delay_us);
                        continue;
                }
                return res;
@@ -570,13 +845,15 @@ static int stlink_cmd_allow_retry(void *handle, const uint8_t *buf, int size)
 static int stlink_usb_read_trace(void *handle, const uint8_t *buf, int size)
 {
        struct stlink_usb_handle_s *h = handle;
+       int tr, ret;
 
        assert(handle != NULL);
 
        assert(h->version.flags & STLINK_F_HAS_TRACE);
 
-       if (jtag_libusb_bulk_read(h->fd, h->trace_ep, (char *)buf,
-                       size, STLINK_READ_TIMEOUT) != size) {
+       ret = jtag_libusb_bulk_read(h->fd, h->trace_ep, (char *)buf, size,
+                                   STLINK_READ_TIMEOUT, &tr);
+       if (ret || tr != size) {
                LOG_ERROR("bulk trace read failed");
                return ERROR_FAIL;
        }
@@ -636,7 +913,10 @@ static int stlink_usb_version(void *handle)
 {
        int res;
        uint32_t flags;
-       uint16_t v;
+       uint16_t version;
+       uint8_t v, x, y, jtag, swim, msd, bridge = 0;
+       char v_str[5 * (1 + 3) + 1]; /* VvJjMmBbSs */
+       char *p;
        struct stlink_usb_handle_s *h = handle;
 
        assert(handle != NULL);
@@ -645,61 +925,161 @@ static int stlink_usb_version(void *handle)
 
        h->cmdbuf[h->cmdidx++] = STLINK_GET_VERSION;
 
-       res = stlink_usb_xfer(handle, h->databuf, 6);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 6);
 
        if (res != ERROR_OK)
                return res;
 
-       v = (h->databuf[0] << 8) | h->databuf[1];
+       version = be_to_h_u16(h->databuf);
+       v = (version >> 12) & 0x0f;
+       x = (version >> 6) & 0x3f;
+       y = version & 0x3f;
+
+       h->vid = le_to_h_u16(h->databuf + 2);
+       h->pid = le_to_h_u16(h->databuf + 4);
+
+       switch (h->pid) {
+       case STLINK_V2_1_PID:
+       case STLINK_V2_1_NO_MSD_PID:
+               if ((x <= 22 && y == 7) || (x >= 25 && y >= 7 && y <= 12)) {
+                       /* MxSy : STM8 V2.1 - SWIM only */
+                       msd = x;
+                       swim = y;
+                       jtag = 0;
+               } else {
+                       /* JxMy : STM32 V2.1 - JTAG/SWD only */
+                       jtag = x;
+                       msd = y;
+                       swim = 0;
+               }
+               break;
+       default:
+               jtag = x;
+               swim = y;
+               msd = 0;
+               break;
+       }
+
+       /* STLINK-V3 requires a specific command */
+       if (v == 3 && x == 0 && y == 0) {
+               stlink_usb_init_buffer(handle, h->rx_ep, 16);
+
+               h->cmdbuf[h->cmdidx++] = STLINK_APIV3_GET_VERSION_EX;
+
+               res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 12);
+               if (res != ERROR_OK)
+                       return res;
+
+               v = h->databuf[0];
+               swim = h->databuf[1];
+               jtag = h->databuf[2];
+               msd  = h->databuf[3];
+               bridge = h->databuf[4];
+               h->vid = le_to_h_u16(h->databuf + 8);
+               h->pid = le_to_h_u16(h->databuf + 10);
+       }
 
-       h->version.stlink = (v >> 12) & 0x0f;
-       h->version.jtag = (v >> 6) & 0x3f;
-       h->version.swim = v & 0x3f;
-       h->vid = buf_get_u32(h->databuf, 16, 16);
-       h->pid = buf_get_u32(h->databuf, 32, 16);
+       h->version.stlink = v;
+       h->version.jtag = jtag;
+       h->version.swim = swim;
 
        flags = 0;
        switch (h->version.stlink) {
        case 1:
                /* ST-LINK/V1 from J11 switch to api-v2 (and support SWD) */
                if (h->version.jtag >= 11)
-                       h->version.jtag_api_max = STLINK_JTAG_API_V2;
+                       h->version.jtag_api = STLINK_JTAG_API_V2;
                else
-                       h->version.jtag_api_max = STLINK_JTAG_API_V1;
+                       h->version.jtag_api = STLINK_JTAG_API_V1;
 
                break;
        case 2:
                /* all ST-LINK/V2 and ST-Link/V2.1 use api-v2 */
-               h->version.jtag_api_max = STLINK_JTAG_API_V2;
+               h->version.jtag_api = STLINK_JTAG_API_V2;
 
                /* API for trace from J13 */
                /* API for target voltage from J13 */
                if (h->version.jtag >= 13)
                        flags |= STLINK_F_HAS_TRACE;
 
+               /* preferred API to get last R/W status from J15 */
+               if (h->version.jtag >= 15)
+                       flags |= STLINK_F_HAS_GETLASTRWSTATUS2;
+
                /* API to set SWD frequency from J22 */
                if (h->version.jtag >= 22)
                        flags |= STLINK_F_HAS_SWD_SET_FREQ;
 
                /* API to set JTAG frequency from J24 */
-               if (h->version.jtag >= 24)
+               /* API to access DAP registers from J24 */
+               if (h->version.jtag >= 24) {
                        flags |= STLINK_F_HAS_JTAG_SET_FREQ;
+                       flags |= STLINK_F_HAS_DAP_REG;
+               }
+
+               /* Quirk for read DP in JTAG mode (V2 only) from J24, fixed in J32 */
+               if (h->version.jtag >= 24 && h->version.jtag < 32)
+                       flags |= STLINK_F_QUIRK_JTAG_DP_READ;
 
                /* API to read/write memory at 16 bit from J26 */
                if (h->version.jtag >= 26)
                        flags |= STLINK_F_HAS_MEM_16BIT;
 
+               /* API required to init AP before any AP access from J28 */
+               if (h->version.jtag >= 28)
+                       flags |= STLINK_F_HAS_AP_INIT;
+
+               /* Banked regs (DPv1 & DPv2) support from V2J32 */
+               if (h->version.jtag >= 32)
+                       flags |= STLINK_F_HAS_DPBANKSEL;
+
+               break;
+       case 3:
+               /* all STLINK-V3 use api-v3 */
+               h->version.jtag_api = STLINK_JTAG_API_V3;
+
+               /* STLINK-V3 is a superset of ST-LINK/V2 */
+
+               /* API for trace */
+               /* API for target voltage */
+               flags |= STLINK_F_HAS_TRACE;
+
+               /* preferred API to get last R/W status */
+               flags |= STLINK_F_HAS_GETLASTRWSTATUS2;
+
+               /* API to access DAP registers */
+               flags |= STLINK_F_HAS_DAP_REG;
+
+               /* API to read/write memory at 16 bit */
+               flags |= STLINK_F_HAS_MEM_16BIT;
+
+               /* API required to init AP before any AP access */
+               flags |= STLINK_F_HAS_AP_INIT;
+
+               /* Banked regs (DPv1 & DPv2) support from V3J2 */
+               if (h->version.jtag >= 2)
+                       flags |= STLINK_F_HAS_DPBANKSEL;
+
                break;
        default:
                break;
        }
        h->version.flags = flags;
 
-       LOG_INFO("STLINK v%d JTAG v%d API v%d SWIM v%d VID 0x%04X PID 0x%04X",
-               h->version.stlink,
-               h->version.jtag,
-               (h->version.jtag_api_max == STLINK_JTAG_API_V1) ? 1 : 2,
-               h->version.swim,
+       p = v_str;
+       p += sprintf(p, "V%d", v);
+       if (jtag || !msd)
+               p += sprintf(p, "J%d", jtag);
+       if (msd)
+               p += sprintf(p, "M%d", msd);
+       if (bridge)
+               p += sprintf(p, "B%d", bridge);
+       if (swim || !msd)
+               sprintf(p, "S%d", swim);
+
+       LOG_INFO("STLINK %s (API v%d) VID:PID %04X:%04X",
+               v_str,
+               h->version.jtag_api,
                h->vid,
                h->pid);
 
@@ -719,7 +1099,7 @@ static int stlink_usb_check_voltage(void *handle, float *target_voltage)
 
        h->cmdbuf[h->cmdidx++] = STLINK_GET_TARGET_VOLTAGE;
 
-       int result = stlink_usb_xfer(handle, h->databuf, 8);
+       int result = stlink_usb_xfer_noerrcheck(handle, h->databuf, 8);
 
        if (result != ERROR_OK)
                return result;
@@ -798,7 +1178,7 @@ static int stlink_usb_current_mode(void *handle, uint8_t *mode)
 
        h->cmdbuf[h->cmdidx++] = STLINK_GET_CURRENT_MODE;
 
-       res = stlink_usb_xfer(handle, h->databuf, 2);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
@@ -820,7 +1200,7 @@ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type)
         * status
         * TODO: we need the test on api V1 too
         */
-       if (h->jtag_api == STLINK_JTAG_API_V2)
+       if (h->version.jtag_api != STLINK_JTAG_API_V1)
                rx_size = 2;
 
        stlink_usb_init_buffer(handle, h->rx_ep, rx_size);
@@ -828,19 +1208,19 @@ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type)
        switch (type) {
                case STLINK_MODE_DEBUG_JTAG:
                        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-                       if (h->jtag_api == STLINK_JTAG_API_V1)
+                       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_ENTER;
                        else
                                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_ENTER;
-                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_JTAG;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_JTAG_NO_RESET;
                        break;
                case STLINK_MODE_DEBUG_SWD:
                        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-                       if (h->jtag_api == STLINK_JTAG_API_V1)
+                       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_ENTER;
                        else
                                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_ENTER;
-                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_SWD;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_SWD_NO_RESET;
                        break;
                case STLINK_MODE_DEBUG_SWIM:
                        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
@@ -886,7 +1266,7 @@ static int stlink_usb_mode_leave(void *handle, enum stlink_mode type)
                        return ERROR_FAIL;
        }
 
-       res = stlink_usb_xfer(handle, 0, 0);
+       res = stlink_usb_xfer_noerrcheck(handle, 0, 0);
 
        if (res != ERROR_OK)
                return res;
@@ -911,7 +1291,7 @@ static enum stlink_mode stlink_get_mode(enum hl_transports t)
 }
 
 /** */
-static int stlink_usb_init_mode(void *handle, bool connect_under_reset)
+static int stlink_usb_init_mode(void *handle, bool connect_under_reset, int initial_interface_speed)
 {
        int res;
        uint8_t mode;
@@ -990,6 +1370,27 @@ static int stlink_usb_init_mode(void *handle, bool connect_under_reset)
                return ERROR_FAIL;
        }
 
+       /* set the speed before entering the mode, as the chip discovery phase should be done at this speed too */
+       if (h->transport == HL_TRANSPORT_JTAG) {
+               if (h->version.flags & STLINK_F_HAS_JTAG_SET_FREQ) {
+                       stlink_dump_speed_map(stlink_khz_to_speed_map_jtag, ARRAY_SIZE(stlink_khz_to_speed_map_jtag));
+                       stlink_speed(h, initial_interface_speed, false);
+               }
+       } else if (h->transport == HL_TRANSPORT_SWD) {
+               if (h->version.flags & STLINK_F_HAS_SWD_SET_FREQ) {
+                       stlink_dump_speed_map(stlink_khz_to_speed_map_swd, ARRAY_SIZE(stlink_khz_to_speed_map_swd));
+                       stlink_speed(h, initial_interface_speed, false);
+               }
+       }
+
+       if (h->version.jtag_api == STLINK_JTAG_API_V3) {
+               struct speed_map map[STLINK_V3_MAX_FREQ_NB];
+
+               stlink_get_com_freq(h, (h->transport == HL_TRANSPORT_JTAG), map);
+               stlink_dump_speed_map(map, ARRAY_SIZE(map));
+               stlink_speed(h, initial_interface_speed, false);
+       }
+
        /* preliminary SRST assert:
         * We want SRST is asserted before activating debug signals (mode_enter).
         * As the required mode has not been set, the adapter may not know what pin to use.
@@ -1032,7 +1433,8 @@ static int stlink_swim_status(void *handle)
        stlink_usb_init_buffer(handle, h->rx_ep, 4);
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_READSTATUS;
-       res = stlink_usb_xfer(handle, h->databuf, 4);
+       /* error is checked by the caller */
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 4);
        if (res != ERROR_OK)
                return res;
        return ERROR_OK;
@@ -1052,7 +1454,7 @@ static int stlink_swim_cap(void *handle, uint8_t *cap)
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_READ_CAP;
        h->cmdbuf[h->cmdidx++] = 0x01;
-       res = stlink_usb_xfer(handle, h->databuf, 8);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 8);
        if (res != ERROR_OK)
                return res;
        memcpy(cap, h->databuf, 8);
@@ -1209,7 +1611,7 @@ static int stlink_swim_readbytes(void *handle, uint32_t addr, uint32_t len, uint
        stlink_usb_init_buffer(handle, h->rx_ep, len);
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
        h->cmdbuf[h->cmdidx++] = STLINK_SWIM_READBUF;
-       res = stlink_usb_xfer(handle, data, len);
+       res = stlink_usb_xfer_noerrcheck(handle, data, len);
        if (res != ERROR_OK)
                return res;
 
@@ -1219,7 +1621,7 @@ static int stlink_swim_readbytes(void *handle, uint32_t addr, uint32_t len, uint
 /** */
 static int stlink_usb_idcode(void *handle, uint32_t *idcode)
 {
-       int res;
+       int res, offset;
        struct stlink_usb_handle_s *h = handle;
 
        assert(handle != NULL);
@@ -1230,17 +1632,25 @@ static int stlink_usb_idcode(void *handle, uint32_t *idcode)
                return ERROR_OK;
        }
 
-       stlink_usb_init_buffer(handle, h->rx_ep, 4);
+       stlink_usb_init_buffer(handle, h->rx_ep, 12);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_READCOREID;
+       if (h->version.jtag_api == STLINK_JTAG_API_V1) {
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_READCOREID;
+
+               res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 4);
+               offset = 0;
+       } else {
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READ_IDCODES;
 
-       res = stlink_usb_xfer(handle, h->databuf, 4);
+               res = stlink_usb_xfer_errcheck(handle, h->databuf, 12);
+               offset = 4;
+       }
 
        if (res != ERROR_OK)
                return res;
 
-       *idcode = le_to_h_u32(h->databuf);
+       *idcode = le_to_h_u32(h->databuf + offset);
 
        LOG_DEBUG("IDCODE: 0x%08" PRIX32, *idcode);
 
@@ -1278,7 +1688,7 @@ static int stlink_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
        stlink_usb_init_buffer(handle, h->rx_ep, 2);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_WRITEDEBUGREG;
        else
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITEDEBUGREG;
@@ -1305,7 +1715,7 @@ static int stlink_usb_trace_read(void *handle, uint8_t *buf, size_t *size)
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GET_TRACE_NB;
 
-               res = stlink_usb_xfer(handle, h->databuf, 2);
+               res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 2);
                if (res != ERROR_OK)
                        return res;
 
@@ -1370,7 +1780,7 @@ static enum target_state stlink_usb_state(void *handle)
                h->reconnect_pending = false;
        }
 
-       if (h->jtag_api == STLINK_JTAG_API_V2) {
+       if (h->version.jtag_api != STLINK_JTAG_API_V1) {
                res = stlink_usb_v2_get_status(handle);
                if (res == TARGET_UNKNOWN)
                        h->reconnect_pending = true;
@@ -1382,7 +1792,7 @@ static enum target_state stlink_usb_state(void *handle)
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_GETSTATUS;
 
-       res = stlink_usb_xfer(handle, h->databuf, 2);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return TARGET_UNKNOWN;
@@ -1433,7 +1843,7 @@ static void stlink_usb_trace_disable(void *handle)
        stlink_usb_init_buffer(handle, h->rx_ep, 2);
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_STOP_TRACE_RX;
-       res = stlink_usb_xfer(handle, h->databuf, 2);
+       res = stlink_usb_xfer_errcheck(handle, h->databuf, 2);
 
        if (res == ERROR_OK)
                h->trace.enabled = false;
@@ -1458,7 +1868,7 @@ static int stlink_usb_trace_enable(void *handle)
                h_u32_to_le(h->cmdbuf+h->cmdidx, h->trace.source_hz);
                h->cmdidx += 4;
 
-               res = stlink_usb_xfer(handle, h->databuf, 2);
+               res = stlink_usb_xfer_errcheck(handle, h->databuf, 2);
 
                if (res == ERROR_OK)  {
                        h->trace.enabled = true;
@@ -1487,7 +1897,7 @@ static int stlink_usb_reset(void *handle)
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
 
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_RESETSYS;
        else
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_RESETSYS;
@@ -1512,7 +1922,7 @@ static int stlink_usb_run(void *handle)
 
        assert(handle != NULL);
 
-       if (h->jtag_api == STLINK_JTAG_API_V2) {
+       if (h->version.jtag_api != STLINK_JTAG_API_V1) {
                res = stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_DEBUGEN);
 
                return res;
@@ -1534,7 +1944,7 @@ static int stlink_usb_halt(void *handle)
 
        assert(handle != NULL);
 
-       if (h->jtag_api == STLINK_JTAG_API_V2) {
+       if (h->version.jtag_api != STLINK_JTAG_API_V1) {
                res = stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_DEBUGEN);
 
                return res;
@@ -1555,7 +1965,7 @@ static int stlink_usb_step(void *handle)
 
        assert(handle != NULL);
 
-       if (h->jtag_api == STLINK_JTAG_API_V2) {
+       if (h->version.jtag_api != STLINK_JTAG_API_V1) {
                /* TODO: this emulates the v1 api, it should really use a similar auto mask isr
                 * that the Cortex-M3 currently does. */
                stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_MASKINTS|C_DEBUGEN);
@@ -1579,20 +1989,21 @@ static int stlink_usb_read_regs(void *handle)
 
        assert(handle != NULL);
 
-       stlink_usb_init_buffer(handle, h->rx_ep, 84);
+       stlink_usb_init_buffer(handle, h->rx_ep, 88);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1) {
+
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_READALLREGS;
-       else
+               res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 84);
+               /* regs data from offset 0 */
+       } else {
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READALLREGS;
+               res = stlink_usb_xfer_errcheck(handle, h->databuf, 88);
+               /* status at offset 0, regs data from offset 4 */
+       }
 
-       res = stlink_usb_xfer(handle, h->databuf, 84);
-
-       if (res != ERROR_OK)
-               return res;
-
-       return ERROR_OK;
+       return res;
 }
 
 /** */
@@ -1603,17 +2014,17 @@ static int stlink_usb_read_reg(void *handle, int num, uint32_t *val)
 
        assert(handle != NULL);
 
-       stlink_usb_init_buffer(handle, h->rx_ep, h->jtag_api == STLINK_JTAG_API_V1 ? 4 : 8);
+       stlink_usb_init_buffer(handle, h->rx_ep, h->version.jtag_api == STLINK_JTAG_API_V1 ? 4 : 8);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_READREG;
        else
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READREG;
        h->cmdbuf[h->cmdidx++] = num;
 
-       if (h->jtag_api == STLINK_JTAG_API_V1) {
-               res = stlink_usb_xfer(handle, h->databuf, 4);
+       if (h->version.jtag_api == STLINK_JTAG_API_V1) {
+               res = stlink_usb_xfer_noerrcheck(handle, h->databuf, 4);
                if (res != ERROR_OK)
                        return res;
                *val = le_to_h_u32(h->databuf);
@@ -1637,7 +2048,7 @@ static int stlink_usb_write_reg(void *handle, int num, uint32_t val)
        stlink_usb_init_buffer(handle, h->rx_ep, 2);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_WRITEREG;
        else
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITEREG;
@@ -1650,25 +2061,23 @@ static int stlink_usb_write_reg(void *handle, int num, uint32_t val)
 
 static int stlink_usb_get_rw_status(void *handle)
 {
-       int res;
        struct stlink_usb_handle_s *h = handle;
 
        assert(handle != NULL);
 
-       if (h->jtag_api == STLINK_JTAG_API_V1)
+       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                return ERROR_OK;
 
        stlink_usb_init_buffer(handle, h->rx_ep, 2);
 
        h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
-       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GETLASTRWSTATUS;
-
-       res = stlink_usb_xfer(handle, h->databuf, 2);
-
-       if (res != ERROR_OK)
-               return res;
-
-       return stlink_usb_error_check(h);
+       if (h->version.flags & STLINK_F_HAS_GETLASTRWSTATUS2) {
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GETLASTRWSTATUS2;
+               return stlink_usb_xfer_errcheck(handle, h->databuf, 12);
+       } else {
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GETLASTRWSTATUS;
+               return stlink_usb_xfer_errcheck(handle, h->databuf, 2);
+       }
 }
 
 /** */
@@ -1681,9 +2090,9 @@ static int stlink_usb_read_mem8(void *handle, uint32_t addr, uint16_t len,
 
        assert(handle != NULL);
 
-       /* max 8bit read/write is 64bytes */
-       if (len > STLINK_MAX_RW8) {
-               LOG_DEBUG("max buffer length exceeded");
+       /* max 8 bit read/write is 64 bytes or 512 bytes for v3 */
+       if (len > stlink_usb_block(h)) {
+               LOG_DEBUG("max buffer (%d) length exceeded", stlink_usb_block(h));
                return ERROR_FAIL;
        }
 
@@ -1700,7 +2109,7 @@ static int stlink_usb_read_mem8(void *handle, uint32_t addr, uint16_t len,
        if (read_len == 1)
                read_len++;
 
-       res = stlink_usb_xfer(handle, h->databuf, read_len);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, read_len);
 
        if (res != ERROR_OK)
                return res;
@@ -1719,9 +2128,9 @@ static int stlink_usb_write_mem8(void *handle, uint32_t addr, uint16_t len,
 
        assert(handle != NULL);
 
-       /* max 8bit read/write is 64bytes */
-       if (len > STLINK_MAX_RW8) {
-               LOG_DEBUG("max buffer length exceeded");
+       /* max 8 bit read/write is 64 bytes or 512 bytes for v3 */
+       if (len > stlink_usb_block(h)) {
+               LOG_DEBUG("max buffer length (%d) exceeded", stlink_usb_block(h));
                return ERROR_FAIL;
        }
 
@@ -1734,7 +2143,7 @@ static int stlink_usb_write_mem8(void *handle, uint32_t addr, uint16_t len,
        h_u16_to_le(h->cmdbuf+h->cmdidx, len);
        h->cmdidx += 2;
 
-       res = stlink_usb_xfer(handle, buffer, len);
+       res = stlink_usb_xfer_noerrcheck(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1769,7 +2178,7 @@ static int stlink_usb_read_mem16(void *handle, uint32_t addr, uint16_t len,
        h_u16_to_le(h->cmdbuf+h->cmdidx, len);
        h->cmdidx += 2;
 
-       res = stlink_usb_xfer(handle, h->databuf, len);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1806,7 +2215,7 @@ static int stlink_usb_write_mem16(void *handle, uint32_t addr, uint16_t len,
        h_u16_to_le(h->cmdbuf+h->cmdidx, len);
        h->cmdidx += 2;
 
-       res = stlink_usb_xfer(handle, buffer, len);
+       res = stlink_usb_xfer_noerrcheck(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1838,7 +2247,7 @@ static int stlink_usb_read_mem32(void *handle, uint32_t addr, uint16_t len,
        h_u16_to_le(h->cmdbuf+h->cmdidx, len);
        h->cmdidx += 2;
 
-       res = stlink_usb_xfer(handle, h->databuf, len);
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1872,7 +2281,7 @@ static int stlink_usb_write_mem32(void *handle, uint32_t addr, uint16_t len,
        h_u16_to_le(h->cmdbuf+h->cmdidx, len);
        h->cmdidx += 2;
 
-       res = stlink_usb_xfer(handle, buffer, len);
+       res = stlink_usb_xfer_noerrcheck(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1906,7 +2315,7 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
        while (count) {
 
                bytes_remaining = (size != 1) ? \
-                               stlink_max_block_size(h->max_mem_packet, addr) : STLINK_MAX_RW8;
+                               stlink_max_block_size(h->max_mem_packet, addr) : stlink_usb_block(h);
 
                if (count < bytes_remaining)
                        bytes_remaining = count;
@@ -1991,7 +2400,7 @@ static int stlink_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
        while (count) {
 
                bytes_remaining = (size != 1) ? \
-                               stlink_max_block_size(h->max_mem_packet, addr) : STLINK_MAX_RW8;
+                               stlink_max_block_size(h->max_mem_packet, addr) : stlink_usb_block(h);
 
                if (count < bytes_remaining)
                        bytes_remaining = count;
@@ -2084,9 +2493,13 @@ static int stlink_match_speed_map(const struct speed_map *map, unsigned int map_
        unsigned int i;
        int speed_index = -1;
        int speed_diff = INT_MAX;
+       int last_valid_speed = -1;
        bool match = true;
 
        for (i = 0; i < map_size; i++) {
+               if (!map[i].speed)
+                       continue;
+               last_valid_speed = i;
                if (khz == map[i].speed) {
                        speed_index = i;
                        break;
@@ -2104,7 +2517,7 @@ static int stlink_match_speed_map(const struct speed_map *map, unsigned int map_
        if (speed_index == -1) {
                /* this will only be here if we cannot match the slow speed.
                 * use the slowest speed we support.*/
-               speed_index = map_size - 1;
+               speed_index = last_valid_speed;
                match = false;
        } else if (i == map_size)
                match = false;
@@ -2169,7 +2582,84 @@ void stlink_dump_speed_map(const struct speed_map *map, unsigned int map_size)
 
        LOG_DEBUG("Supported clock speeds are:");
        for (i = 0; i < map_size; i++)
-               LOG_DEBUG("%d kHz", map[i].speed);
+               if (map[i].speed)
+                       LOG_DEBUG("%d kHz", map[i].speed);
+}
+
+static int stlink_get_com_freq(void *handle, bool is_jtag, struct speed_map *map)
+{
+       struct stlink_usb_handle_s *h = handle;
+       int i;
+
+       if (h->version.jtag_api != STLINK_JTAG_API_V3) {
+               LOG_ERROR("Unknown command");
+               return 0;
+       }
+
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_APIV3_GET_COM_FREQ;
+       h->cmdbuf[h->cmdidx++] = is_jtag ? 1 : 0;
+
+       int res = stlink_usb_xfer_errcheck(handle, h->databuf, 52);
+
+       int size = h->databuf[8];
+
+       if (size > STLINK_V3_MAX_FREQ_NB)
+               size = STLINK_V3_MAX_FREQ_NB;
+
+       for (i = 0; i < size; i++) {
+               map[i].speed = le_to_h_u32(&h->databuf[12 + 4 * i]);
+               map[i].speed_divisor = i;
+       }
+
+       /* set to zero all the next entries */
+       for (i = size; i < STLINK_V3_MAX_FREQ_NB; i++)
+               map[i].speed = 0;
+
+       return res;
+}
+
+static int stlink_set_com_freq(void *handle, bool is_jtag, unsigned int frequency)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       if (h->version.jtag_api != STLINK_JTAG_API_V3) {
+               LOG_ERROR("Unknown command");
+               return 0;
+       }
+
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_APIV3_SET_COM_FREQ;
+       h->cmdbuf[h->cmdidx++] = is_jtag ? 1 : 0;
+       h->cmdbuf[h->cmdidx++] = 0;
+
+       h_u32_to_le(&h->cmdbuf[4], frequency);
+
+       return stlink_usb_xfer_errcheck(handle, h->databuf, 8);
+}
+
+static int stlink_speed_v3(void *handle, bool is_jtag, int khz, bool query)
+{
+       struct stlink_usb_handle_s *h = handle;
+       int speed_index;
+       struct speed_map map[STLINK_V3_MAX_FREQ_NB];
+
+       stlink_get_com_freq(h, is_jtag, map);
+
+       speed_index = stlink_match_speed_map(map, ARRAY_SIZE(map), khz, query);
+
+       if (!query) {
+               int result = stlink_set_com_freq(h, is_jtag, map[speed_index].speed);
+               if (result != ERROR_OK) {
+                       LOG_ERROR("Unable to set adapter speed");
+                       return khz;
+               }
+       }
+       return map[speed_index].speed;
 }
 
 static int stlink_speed(void *handle, int khz, bool query)
@@ -2179,12 +2669,25 @@ static int stlink_speed(void *handle, int khz, bool query)
        if (!handle)
                return khz;
 
-       if (h->transport == HL_TRANSPORT_SWIM)
+       switch (h->transport) {
+       case HL_TRANSPORT_SWIM:
                return stlink_speed_swim(handle, khz, query);
-       else if (h->transport == HL_TRANSPORT_SWD)
-               return stlink_speed_swd(handle, khz, query);
-       else if (h->transport == HL_TRANSPORT_JTAG)
-               return stlink_speed_jtag(handle, khz, query);
+               break;
+       case HL_TRANSPORT_SWD:
+               if (h->version.jtag_api == STLINK_JTAG_API_V3)
+                       return stlink_speed_v3(handle, false, khz, query);
+               else
+                       return stlink_speed_swd(handle, khz, query);
+               break;
+       case HL_TRANSPORT_JTAG:
+               if (h->version.jtag_api == STLINK_JTAG_API_V3)
+                       return stlink_speed_v3(handle, true, khz, query);
+               else
+                       return stlink_speed_jtag(handle, khz, query);
+               break;
+       default:
+               break;
+       }
 
        return khz;
 }
@@ -2242,7 +2745,6 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
 {
        int err, retry_count = 1;
        struct stlink_usb_handle_s *h;
-       enum stlink_jtag_api_version api;
 
        LOG_DEBUG("stlink_usb_open");
 
@@ -2298,6 +2800,14 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
                                h->version.stlink = 1;
                                h->tx_ep = STLINK_TX_EP;
                                break;
+                       case STLINK_V3_USBLOADER_PID:
+                       case STLINK_V3E_PID:
+                       case STLINK_V3S_PID:
+                       case STLINK_V3_2VCP_PID:
+                               h->version.stlink = 3;
+                               h->tx_ep = STLINK_V2_1_TX_EP;
+                               h->trace_ep = STLINK_V2_1_TRACE_EP;
+                               break;
                        case STLINK_V2_1_PID:
                        case STLINK_V2_1_NO_MSD_PID:
                                h->version.stlink = 2;
@@ -2350,7 +2860,7 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
 
        switch (h->transport) {
                case HL_TRANSPORT_SWD:
-                       if (h->version.jtag_api_max == STLINK_JTAG_API_V1)
+                       if (h->version.jtag_api == STLINK_JTAG_API_V1)
                                err = ERROR_FAIL;
                        /* fall-through */
                case HL_TRANSPORT_JTAG:
@@ -2371,15 +2881,8 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
                goto error_open;
        }
 
-       api = h->version.jtag_api_max;
-
-       LOG_INFO("using stlink api v%d", api);
-
-       /* set the used jtag api, this will default to the newest supported version */
-       h->jtag_api = api;
-
        /* initialize the debug hardware */
-       err = stlink_usb_init_mode(h, param->connect_under_reset);
+       err = stlink_usb_init_mode(h, param->connect_under_reset, param->initial_interface_speed);
 
        if (err != ERROR_OK) {
                LOG_ERROR("init mode failed (unable to connect to the target)");
@@ -2397,18 +2900,6 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
                return ERROR_OK;
        }
 
-       if (h->transport == HL_TRANSPORT_JTAG) {
-               if (h->version.flags & STLINK_F_HAS_JTAG_SET_FREQ) {
-                       stlink_dump_speed_map(stlink_khz_to_speed_map_jtag, ARRAY_SIZE(stlink_khz_to_speed_map_jtag));
-                       stlink_speed(h, param->initial_interface_speed, false);
-               }
-       } else if (h->transport == HL_TRANSPORT_SWD) {
-               if (h->version.flags & STLINK_F_HAS_SWD_SET_FREQ) {
-                       stlink_dump_speed_map(stlink_khz_to_speed_map_swd, ARRAY_SIZE(stlink_khz_to_speed_map_swd));
-                       stlink_speed(h, param->initial_interface_speed, false);
-               }
-       }
-
        /* get cpuid, so we can determine the max page size
         * start with a safe default */
        h->max_mem_packet = (1 << 10);
@@ -2436,10 +2927,13 @@ error_open:
        return ERROR_FAIL;
 }
 
-int stlink_config_trace(void *handle, bool enabled, enum tpiu_pin_protocol pin_protocol,
-                       uint32_t port_size, unsigned int *trace_freq)
+int stlink_config_trace(void *handle, bool enabled,
+               enum tpiu_pin_protocol pin_protocol, uint32_t port_size,
+               unsigned int *trace_freq, unsigned int traceclkin_freq,
+               uint16_t *prescaler)
 {
        struct stlink_usb_handle_s *h = handle;
+       uint16_t presc;
 
        if (enabled && (!(h->version.flags & STLINK_F_HAS_TRACE) ||
                        pin_protocol != TPIU_PIN_PROTOCOL_ASYNC_UART)) {
@@ -2462,9 +2956,105 @@ int stlink_config_trace(void *handle, bool enabled, enum tpiu_pin_protocol pin_p
 
        if (!*trace_freq)
                *trace_freq = STLINK_TRACE_MAX_HZ;
-       h->trace.source_hz = *trace_freq;
 
-       return stlink_usb_trace_enable(h);
+       presc = traceclkin_freq / *trace_freq;
+
+       if (traceclkin_freq % *trace_freq > 0)
+               presc++;
+
+       if (presc > TPIU_ACPR_MAX_SWOSCALER) {
+               LOG_ERROR("SWO frequency is not suitable. Please choose a different "
+                       "frequency.");
+               return ERROR_FAIL;
+       }
+
+       *prescaler = presc;
+       h->trace.source_hz = *trace_freq;
+
+       return stlink_usb_trace_enable(h);
+}
+
+/** */
+static int stlink_usb_init_access_port(void *handle, unsigned char ap_num)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_AP_INIT))
+               return ERROR_COMMAND_NOTFOUND;
+
+       LOG_DEBUG_IO("init ap_num = %d", ap_num);
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_INIT_AP;
+       h->cmdbuf[h->cmdidx++] = ap_num;
+
+       return stlink_usb_xfer_errcheck(handle, h->databuf, 2);
+}
+
+/** */
+static int stlink_usb_close_access_port(void *handle, unsigned char ap_num)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_AP_INIT))
+               return ERROR_COMMAND_NOTFOUND;
+
+       LOG_DEBUG_IO("close ap_num = %d", ap_num);
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_CLOSE_AP_DBG;
+       h->cmdbuf[h->cmdidx++] = ap_num;
+
+       return stlink_usb_xfer_errcheck(handle, h->databuf, 2);
+}
+
+/** */
+static int stlink_read_dap_register(void *handle, unsigned short dap_port,
+                       unsigned short addr, uint32_t *val)
+{
+       struct stlink_usb_handle_s *h = handle;
+       int retval;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_DAP_REG))
+               return ERROR_COMMAND_NOTFOUND;
+
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READ_DAP_REG;
+       h_u16_to_le(&h->cmdbuf[2], dap_port);
+       h_u16_to_le(&h->cmdbuf[4], addr);
+
+       retval = stlink_usb_xfer_errcheck(handle, h->databuf, 8);
+       *val = le_to_h_u32(h->databuf + 4);
+       LOG_DEBUG_IO("dap_port_read = %d, addr =  0x%x, value = 0x%x", dap_port, addr, *val);
+       return retval;
+}
+
+/** */
+static int stlink_write_dap_register(void *handle, unsigned short dap_port,
+                       unsigned short addr, uint32_t val)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_DAP_REG))
+               return ERROR_COMMAND_NOTFOUND;
+
+       LOG_DEBUG_IO("dap_write port = %d, addr = 0x%x, value = 0x%x", dap_port, addr, val);
+       stlink_usb_init_buffer(handle, h->rx_ep, 16);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITE_DAP_REG;
+       h_u16_to_le(&h->cmdbuf[2], dap_port);
+       h_u16_to_le(&h->cmdbuf[4], addr);
+       h_u32_to_le(&h->cmdbuf[6], val);
+       return stlink_usb_xfer_errcheck(handle, h->databuf, 2);
 }
 
 /** */
@@ -2508,3 +3098,549 @@ struct hl_layout_api_s stlink_usb_layout_api = {
        /** */
        .poll_trace = stlink_usb_trace_read,
 };
+
+/*****************************************************************************
+ * DAP direct interface
+ */
+
+static struct stlink_usb_handle_s *stlink_dap_handle;
+static struct hl_interface_param_s stlink_dap_param;
+static DECLARE_BITMAP(opened_ap, DP_APSEL_MAX + 1);
+static int stlink_dap_error = ERROR_OK;
+
+static int stlink_dap_op_queue_dp_read(struct adiv5_dap *dap, unsigned reg,
+               uint32_t *data);
+
+/** */
+static int stlink_dap_record_error(int error)
+{
+       if (stlink_dap_error == ERROR_OK)
+               stlink_dap_error = error;
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_get_and_clear_error(void)
+{
+       int retval = stlink_dap_error;
+       stlink_dap_error = ERROR_OK;
+       return retval;
+}
+
+/** */
+static int stlink_dap_open_ap(unsigned short apsel)
+{
+       int retval;
+
+       /* nothing to do on old versions */
+       if (!(stlink_dap_handle->version.flags & STLINK_F_HAS_AP_INIT))
+               return ERROR_OK;
+
+       if (apsel > DP_APSEL_MAX)
+               return ERROR_FAIL;
+
+       if (test_bit(apsel, opened_ap))
+               return ERROR_OK;
+
+       retval = stlink_usb_init_access_port(stlink_dap_handle, apsel);
+       if (retval != ERROR_OK)
+               return retval;
+
+       LOG_DEBUG("AP %d enabled", apsel);
+       set_bit(apsel, opened_ap);
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_closeall_ap(void)
+{
+       int retval, apsel;
+
+       /* nothing to do on old versions */
+       if (!(stlink_dap_handle->version.flags & STLINK_F_HAS_AP_INIT))
+               return ERROR_OK;
+
+       for (apsel = 0; apsel <= DP_APSEL_MAX; apsel++) {
+               if (!test_bit(apsel, opened_ap))
+                       continue;
+               retval = stlink_usb_close_access_port(stlink_dap_handle, apsel);
+               if (retval != ERROR_OK)
+                       return retval;
+               clear_bit(apsel, opened_ap);
+       }
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_reinit_interface(void)
+{
+       int retval;
+       enum stlink_mode mode;
+
+       /*
+        * On JTAG only, it should be enough to call stlink_usb_reset(). But on
+        * some firmware version it does not work as expected, and there is no
+        * equivalent for SWD.
+        * At least for now, to reset the interface quit from JTAG/SWD mode then
+        * select the mode again.
+        */
+
+       mode = stlink_get_mode(stlink_dap_param.transport);
+       if (!stlink_dap_handle->reconnect_pending) {
+               stlink_dap_handle->reconnect_pending = true;
+               stlink_usb_mode_leave(stlink_dap_handle, mode);
+       }
+
+       retval = stlink_usb_mode_enter(stlink_dap_handle, mode);
+       if (retval != ERROR_OK)
+               return retval;
+
+       stlink_dap_handle->reconnect_pending = false;
+       /* on new FW, calling mode-leave closes all the opened AP; reopen them! */
+       if (stlink_dap_handle->version.flags & STLINK_F_HAS_AP_INIT)
+               for (int apsel = 0; apsel <= DP_APSEL_MAX; apsel++)
+                       if (test_bit(apsel, opened_ap)) {
+                               clear_bit(apsel, opened_ap);
+                               stlink_dap_open_ap(apsel);
+                       }
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_op_connect(struct adiv5_dap *dap)
+{
+       uint32_t idcode;
+       int retval;
+
+       LOG_INFO("stlink_dap_op_connect(%sconnect)", dap->do_reconnect ? "re" : "");
+
+       /* Check if we should reset srst already when connecting, but not if reconnecting. */
+       if (!dap->do_reconnect) {
+               enum reset_types jtag_reset_config = jtag_get_reset_config();
+
+               if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+                       if (jtag_reset_config & RESET_SRST_NO_GATING)
+                               adapter_assert_reset();
+                       else
+                               LOG_WARNING("\'srst_nogate\' reset_config option is required");
+               }
+       }
+
+       dap->do_reconnect = false;
+       dap_invalidate_cache(dap);
+
+       retval = dap_dp_init(dap);
+       if (retval != ERROR_OK) {
+               dap->do_reconnect = true;
+               return retval;
+       }
+
+       retval = stlink_usb_idcode(stlink_dap_handle, &idcode);
+       if (retval == ERROR_OK)
+               LOG_INFO("%s %#8.8" PRIx32,
+                       (stlink_dap_handle->transport == HL_TRANSPORT_JTAG) ? "JTAG IDCODE" : "SWD DPIDR",
+                       idcode);
+       else
+               dap->do_reconnect = true;
+
+       return retval;
+}
+
+/** */
+static int stlink_dap_check_reconnect(struct adiv5_dap *dap)
+{
+       int retval;
+
+       if (!dap->do_reconnect)
+               return ERROR_OK;
+
+       retval = stlink_dap_reinit_interface();
+       if (retval != ERROR_OK)
+               return retval;
+
+       return stlink_dap_op_connect(dap);
+}
+
+/** */
+static int stlink_dap_op_send_sequence(struct adiv5_dap *dap, enum swd_special_seq seq)
+{
+       /* Ignore the request */
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_op_queue_dp_read(struct adiv5_dap *dap, unsigned reg,
+               uint32_t *data)
+{
+       uint32_t dummy;
+       int retval;
+
+       if (!(stlink_dap_handle->version.flags & STLINK_F_HAS_DPBANKSEL))
+               if (reg & 0x000000F0) {
+                       LOG_ERROR("Banked DP registers not supported in current STLink FW");
+                       return ERROR_COMMAND_NOTFOUND;
+               }
+
+       retval = stlink_dap_check_reconnect(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       data = data ? : &dummy;
+       if (stlink_dap_handle->version.flags & STLINK_F_QUIRK_JTAG_DP_READ
+               && stlink_dap_handle->transport == HL_TRANSPORT_JTAG) {
+               /* Quirk required in JTAG. Read RDBUFF to get the data */
+               retval = stlink_read_dap_register(stlink_dap_handle,
+                                       STLINK_DEBUG_PORT_ACCESS, reg, &dummy);
+               if (retval == ERROR_OK)
+                       retval = stlink_read_dap_register(stlink_dap_handle,
+                                               STLINK_DEBUG_PORT_ACCESS, DP_RDBUFF, data);
+       } else {
+               retval = stlink_read_dap_register(stlink_dap_handle,
+                                       STLINK_DEBUG_PORT_ACCESS, reg, data);
+       }
+
+       return stlink_dap_record_error(retval);
+}
+
+/** */
+static int stlink_dap_op_queue_dp_write(struct adiv5_dap *dap, unsigned reg,
+               uint32_t data)
+{
+       int retval;
+
+       if (!(stlink_dap_handle->version.flags & STLINK_F_HAS_DPBANKSEL))
+               if (reg & 0x000000F0) {
+                       LOG_ERROR("Banked DP registers not supported in current STLink FW");
+                       return ERROR_COMMAND_NOTFOUND;
+               }
+
+       if (reg == DP_SELECT && (data & DP_SELECT_DPBANK) != 0) {
+               /* ignored if STLINK_F_HAS_DPBANKSEL, not properly managed otherwise */
+               LOG_DEBUG("Ignoring DPBANKSEL while write SELECT");
+               data &= ~DP_SELECT_DPBANK;
+       }
+
+       retval = stlink_dap_check_reconnect(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       /* ST-Link does not like that we set CORUNDETECT */
+       if (reg == DP_CTRL_STAT)
+               data &= ~CORUNDETECT;
+
+       retval = stlink_write_dap_register(stlink_dap_handle,
+                               STLINK_DEBUG_PORT_ACCESS, reg, data);
+       return stlink_dap_record_error(retval);
+}
+
+/** */
+static int stlink_dap_op_queue_ap_read(struct adiv5_ap *ap, unsigned reg,
+               uint32_t *data)
+{
+       struct adiv5_dap *dap = ap->dap;
+       uint32_t dummy;
+       int retval;
+
+       retval = stlink_dap_check_reconnect(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       if (reg != AP_REG_IDR) {
+               retval = stlink_dap_open_ap(ap->ap_num);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
+       data = data ? : &dummy;
+       retval = stlink_read_dap_register(stlink_dap_handle, ap->ap_num, reg,
+                                data);
+       dap->stlink_flush_ap_write = false;
+       return stlink_dap_record_error(retval);
+}
+
+/** */
+static int stlink_dap_op_queue_ap_write(struct adiv5_ap *ap, unsigned reg,
+               uint32_t data)
+{
+       struct adiv5_dap *dap = ap->dap;
+       int retval;
+
+       retval = stlink_dap_check_reconnect(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = stlink_dap_open_ap(ap->ap_num);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = stlink_write_dap_register(stlink_dap_handle, ap->ap_num, reg,
+                               data);
+       dap->stlink_flush_ap_write = true;
+       return stlink_dap_record_error(retval);
+}
+
+/** */
+static int stlink_dap_op_queue_ap_abort(struct adiv5_dap *dap, uint8_t *ack)
+{
+       LOG_WARNING("stlink_dap_op_queue_ap_abort()");
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_op_run(struct adiv5_dap *dap)
+{
+       uint32_t ctrlstat, pwrmask;
+       int retval, saved_retval;
+
+       /* Here no LOG_DEBUG. This is called continuously! */
+
+       /*
+        * ST-Link returns immediately after a DAP write, without waiting for it
+        * to complete.
+        * Run a dummy read to DP_RDBUFF, as suggested in
+        * http://infocenter.arm.com/help/topic/com.arm.doc.faqs/ka16363.html
+        */
+       if (dap->stlink_flush_ap_write) {
+               dap->stlink_flush_ap_write = false;
+               retval = stlink_dap_op_queue_dp_read(dap, DP_RDBUFF, NULL);
+               if (retval != ERROR_OK) {
+                       dap->do_reconnect = true;
+                       return retval;
+               }
+       }
+
+       saved_retval = stlink_dap_get_and_clear_error();
+
+       retval = stlink_dap_op_queue_dp_read(dap, DP_CTRL_STAT, &ctrlstat);
+       if (retval != ERROR_OK) {
+               dap->do_reconnect = true;
+               return retval;
+       }
+       retval = stlink_dap_get_and_clear_error();
+       if (retval != ERROR_OK) {
+               LOG_ERROR("Fail reading CTRL/STAT register. Force reconnect");
+               dap->do_reconnect = true;
+               return retval;
+       }
+
+       if (ctrlstat & SSTICKYERR) {
+               if (stlink_dap_param.transport == HL_TRANSPORT_JTAG)
+                       retval = stlink_dap_op_queue_dp_write(dap, DP_CTRL_STAT,
+                                       ctrlstat & (dap->dp_ctrl_stat | SSTICKYERR));
+               else
+                       retval = stlink_dap_op_queue_dp_write(dap, DP_ABORT, STKERRCLR);
+               if (retval != ERROR_OK) {
+                       dap->do_reconnect = true;
+                       return retval;
+               }
+               retval = stlink_dap_get_and_clear_error();
+               if (retval != ERROR_OK) {
+                       dap->do_reconnect = true;
+                       return retval;
+               }
+       }
+
+       /* check for power lost */
+       pwrmask = dap->dp_ctrl_stat & (CDBGPWRUPREQ | CSYSPWRUPREQ);
+       if ((ctrlstat & pwrmask) != pwrmask)
+               dap->do_reconnect = true;
+
+       return saved_retval;
+}
+
+/** */
+static void stlink_dap_op_quit(struct adiv5_dap *dap)
+{
+       int retval;
+
+       retval = stlink_dap_closeall_ap();
+       if (retval != ERROR_OK)
+               LOG_ERROR("Error closing APs");
+}
+
+/** */
+COMMAND_HANDLER(stlink_dap_serial_command)
+{
+       LOG_DEBUG("stlink_dap_serial_command");
+
+       if (CMD_ARGC != 1) {
+               LOG_ERROR("Expected exactly one argument for \"st-link serial <serial-number>\".");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       if (stlink_dap_param.serial) {
+               LOG_WARNING("Command \"st-link serial\" already used. Replacing previous value");
+               free((void *)stlink_dap_param.serial);
+       }
+
+       stlink_dap_param.serial = strdup(CMD_ARGV[0]);
+       return ERROR_OK;
+}
+
+/** */
+COMMAND_HANDLER(stlink_dap_vid_pid)
+{
+       unsigned int i, max_usb_ids = HLA_MAX_USB_IDS;
+
+       if (CMD_ARGC > max_usb_ids * 2) {
+               LOG_WARNING("ignoring extra IDs in vid_pid "
+                       "(maximum is %d pairs)", max_usb_ids);
+               CMD_ARGC = max_usb_ids * 2;
+       }
+       if (CMD_ARGC < 2 || (CMD_ARGC & 1)) {
+               LOG_WARNING("incomplete vid_pid configuration directive");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+       for (i = 0; i < CMD_ARGC; i += 2) {
+               COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i], stlink_dap_param.vid[i / 2]);
+               COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], stlink_dap_param.pid[i / 2]);
+       }
+
+       /* null termination */
+       stlink_dap_param.vid[i / 2] = stlink_dap_param.pid[i / 2] = 0;
+
+       return ERROR_OK;
+}
+
+/** */
+static const struct command_registration stlink_dap_subcommand_handlers[] = {
+       {
+               .name = "serial",
+               .handler = stlink_dap_serial_command,
+               .mode = COMMAND_CONFIG,
+               .help = "set the serial number of the adapter",
+               .usage = "<serial_number>",
+       },
+       {
+               .name = "vid_pid",
+               .handler = stlink_dap_vid_pid,
+               .mode = COMMAND_CONFIG,
+               .help = "USB VID and PID of the adapter",
+               .usage = "(vid pid)+",
+       },
+       COMMAND_REGISTRATION_DONE
+};
+
+/** */
+static const struct command_registration stlink_dap_command_handlers[] = {
+       {
+               .name = "st-link",
+               .mode = COMMAND_ANY,
+               .help = "perform st-link management",
+               .chain = stlink_dap_subcommand_handlers,
+               .usage = "",
+       },
+       COMMAND_REGISTRATION_DONE
+};
+
+/** */
+static int stlink_dap_init(void)
+{
+       enum reset_types jtag_reset_config = jtag_get_reset_config();
+       int retval;
+
+       LOG_DEBUG("stlink_dap_init()");
+
+       if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+               if (jtag_reset_config & RESET_SRST_NO_GATING)
+                       stlink_dap_param.connect_under_reset = true;
+               else
+                       LOG_WARNING("\'srst_nogate\' reset_config option is required");
+       }
+
+       if (transport_is_dapdirect_swd())
+               stlink_dap_param.transport = HL_TRANSPORT_SWD;
+       else if (transport_is_dapdirect_jtag())
+               stlink_dap_param.transport = HL_TRANSPORT_JTAG;
+       else {
+               LOG_ERROR("Unsupported transport");
+               return ERROR_FAIL;
+       }
+
+       retval = stlink_usb_open(&stlink_dap_param, (void **)&stlink_dap_handle);
+       if (retval != ERROR_OK)
+               return retval;
+
+       if (!(stlink_dap_handle->version.flags & STLINK_F_HAS_DAP_REG)) {
+               LOG_ERROR("ST-Link version does not support DAP direct transport");
+               return ERROR_FAIL;
+       }
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_quit(void)
+{
+       LOG_DEBUG("stlink_dap_quit()");
+
+       free((void *)stlink_dap_param.serial);
+       stlink_dap_param.serial = NULL;
+
+       return stlink_usb_close(stlink_dap_handle);
+}
+
+/** */
+static int stlink_dap_reset(int req_trst, int req_srst)
+{
+       LOG_DEBUG("stlink_dap_reset(%d)", req_srst);
+       return stlink_usb_assert_srst(stlink_dap_handle,
+               req_srst ? STLINK_DEBUG_APIV2_DRIVE_NRST_LOW
+                                : STLINK_DEBUG_APIV2_DRIVE_NRST_HIGH);
+}
+
+/** */
+static int stlink_dap_speed(int speed)
+{
+       if (speed == 0) {
+               LOG_ERROR("RTCK not supported. Set nonzero adapter_khz.");
+               return ERROR_JTAG_NOT_IMPLEMENTED;
+       }
+
+       stlink_dap_param.initial_interface_speed = speed;
+       stlink_speed(stlink_dap_handle, speed, false);
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_khz(int khz, int *jtag_speed)
+{
+       *jtag_speed = khz;
+       return ERROR_OK;
+}
+
+/** */
+static int stlink_dap_speed_div(int speed, int *khz)
+{
+       *khz = speed;
+       return ERROR_OK;
+}
+
+static const struct dap_ops stlink_dap_ops = {
+       .connect = stlink_dap_op_connect,
+       .send_sequence = stlink_dap_op_send_sequence,
+       .queue_dp_read = stlink_dap_op_queue_dp_read,
+       .queue_dp_write = stlink_dap_op_queue_dp_write,
+       .queue_ap_read = stlink_dap_op_queue_ap_read,
+       .queue_ap_write = stlink_dap_op_queue_ap_write,
+       .queue_ap_abort = stlink_dap_op_queue_ap_abort,
+       .run = stlink_dap_op_run,
+       .sync = NULL, /* optional */
+       .quit = stlink_dap_op_quit, /* optional */
+};
+
+static const char *const stlink_dap_transport[] = { "dapdirect_jtag", "dapdirect_swd", NULL };
+
+struct adapter_driver stlink_dap_adapter_driver = {
+       .name = "st-link",
+       .transports = stlink_dap_transport,
+       .commands = stlink_dap_command_handlers,
+
+       .init = stlink_dap_init,
+       .quit = stlink_dap_quit,
+       .reset = stlink_dap_reset,
+       .speed = stlink_dap_speed,
+       .khz = stlink_dap_khz,
+       .speed_div = stlink_dap_speed_div,
+
+       .dap_jtag_ops = &stlink_dap_ops,
+       .dap_swd_ops = &stlink_dap_ops,
+};