drivers/stlink_usb: use command STLINK_DEBUG_APIV2_READ_IDCODES
[fw/openocd] / src / jtag / drivers / stlink_usb.c
index 99f96b9c9c9c521678d2835e1a8cd79f866d5f81..491f2e4ff2ceb41857374dc1a9f5925f5db17df1 100644 (file)
 
 #include "libusb_common.h"
 
+#ifdef HAVE_LIBUSB1
+#define USE_LIBUSB_ASYNCIO
+#endif
+
 #define ENDPOINT_IN  0x80
 #define ENDPOINT_OUT 0x00
 
 #define STLINK_V1_PID         (0x3744)
 #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.
@@ -76,6 +89,7 @@
 enum stlink_jtag_api_version {
        STLINK_JTAG_API_V1 = 1,
        STLINK_JTAG_API_V2,
+       STLINK_JTAG_API_V3,
 };
 
 /** */
@@ -86,8 +100,10 @@ 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;
 };
 
 /** */
@@ -120,8 +136,6 @@ 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 */
@@ -142,6 +156,7 @@ 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
@@ -153,6 +168,8 @@ 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
@@ -204,7 +221,6 @@ 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
@@ -222,8 +238,9 @@ 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
@@ -241,10 +258,21 @@ 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_READMEM_16BIT   0x47
+#define STLINK_DEBUG_APIV2_WRITEMEM_16BIT  0x48
+
+#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
@@ -252,7 +280,8 @@ struct stlink_usb_handle_s {
 
 #define STLINK_TRACE_SIZE               4096
 #define STLINK_TRACE_MAX_HZ             2000000
-#define STLINK_TRACE_MIN_VERSION        13
+
+#define STLINK_V3_MAX_FREQ_NB               10
 
 /** */
 enum stlink_mode {
@@ -267,10 +296,26 @@ enum stlink_mode {
 #define REQUEST_SENSE        0x03
 #define REQUEST_SENSE_LENGTH 18
 
-static const struct {
+/*
+ * 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_GETLASTRWSTATUS2   (1UL << 4)
+
+/* aliases */
+#define STLINK_F_HAS_TARGET_VOLT        STLINK_F_HAS_TRACE
+
+struct speed_map {
        int speed;
        int speed_divisor;
-} stlink_khz_to_speed_map[] = {
+};
+
+/* SWD clock speed */
+static const struct speed_map stlink_khz_to_speed_map_swd[] = {
        {4000, 0},
        {1800, 1}, /* default */
        {1200, 2},
@@ -285,9 +330,188 @@ static const struct {
        {5,  798}
 };
 
+/* JTAG clock speed */
+static const struct speed_map stlink_khz_to_speed_map_jtag[] = {
+       {18000, 2},
+       {9000,  4},
+       {4500,  8},
+       {2250, 16},
+       {1125, 32}, /* default */
+       {562,  64},
+       {281, 128},
+       {140, 256}
+};
+
 static void stlink_usb_init_buffer(void *handle, uint8_t direction, uint32_t size);
 static int stlink_swim_status(void *handle);
 
+/** */
+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)
 {
@@ -321,7 +545,45 @@ 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);
+
+       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;
@@ -349,6 +611,7 @@ 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)
@@ -381,8 +644,9 @@ 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;
@@ -438,7 +702,7 @@ 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]) {
@@ -453,6 +717,9 @@ 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;
@@ -491,12 +758,31 @@ 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.
 
@@ -513,7 +799,7 @@ 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;
                }
@@ -526,7 +812,9 @@ 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;
@@ -540,7 +828,7 @@ static int stlink_usb_read_trace(void *handle, const uint8_t *buf, int size)
 
        assert(handle != NULL);
 
-       assert(h->version.stlink >= 2);
+       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) {
@@ -602,7 +890,11 @@ static void stlink_usb_init_buffer(void *handle, uint8_t direction, uint32_t siz
 static int stlink_usb_version(void *handle)
 {
        int res;
-       uint16_t v;
+       uint32_t flags;
+       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);
@@ -611,32 +903,136 @@ 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->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->cmdbuf[h->cmdidx++] = STLINK_APIV3_GET_VERSION_EX;
 
-       /* set the supported jtag api version
-        * API V2 is supported since JTAG V11
-        */
-       if (h->version.jtag >= 11)
-               h->version.jtag_api_max = STLINK_JTAG_API_V2;
-       else
-               h->version.jtag_api_max = STLINK_JTAG_API_V1;
+               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;
+       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 = STLINK_JTAG_API_V2;
+               else
+                       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 = 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)
+                       flags |= STLINK_F_HAS_JTAG_SET_FREQ;
+
+               /* API to read/write memory at 16 bit from J26 */
+               if (h->version.jtag >= 26)
+                       flags |= STLINK_F_HAS_MEM_16BIT;
+
+               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 */
 
-       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,
+               /* 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 read/write memory at 16 bit */
+               flags |= STLINK_F_HAS_MEM_16BIT;
+
+               break;
+       default:
+               break;
+       }
+       h->version.flags = flags;
+
+       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);
 
@@ -648,15 +1044,15 @@ static int stlink_usb_check_voltage(void *handle, float *target_voltage)
        struct stlink_usb_handle_s *h = handle;
        uint32_t adc_results[2];
 
-       /* only supported by stlink/v2 and for firmware >= 13 */
-       if (h->version.stlink == 1 || h->version.jtag < 13)
+       /* no error message, simply quit with error */
+       if (!(h->version.flags & STLINK_F_HAS_TARGET_VOLT))
                return ERROR_COMMAND_NOTFOUND;
 
        stlink_usb_init_buffer(handle, h->rx_ep, 8);
 
        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;
@@ -681,8 +1077,7 @@ static int stlink_usb_set_swdclk(void *handle, uint16_t clk_divisor)
 
        assert(handle != NULL);
 
-       /* only supported by stlink/v2 and for firmware >= 22 */
-       if (h->version.stlink == 1 || h->version.jtag < 22)
+       if (!(h->version.flags & STLINK_F_HAS_SWD_SET_FREQ))
                return ERROR_COMMAND_NOTFOUND;
 
        stlink_usb_init_buffer(handle, h->rx_ep, 2);
@@ -700,6 +1095,30 @@ static int stlink_usb_set_swdclk(void *handle, uint16_t clk_divisor)
        return ERROR_OK;
 }
 
+static int stlink_usb_set_jtagclk(void *handle, uint16_t clk_divisor)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_JTAG_SET_FREQ))
+               return ERROR_COMMAND_NOTFOUND;
+
+       stlink_usb_init_buffer(handle, h->rx_ep, 2);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_JTAG_SET_FREQ;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, clk_divisor);
+       h->cmdidx += 2;
+
+       int result = stlink_cmd_allow_retry(handle, h->databuf, 2);
+
+       if (result != ERROR_OK)
+               return result;
+
+       return ERROR_OK;
+}
+
 /** */
 static int stlink_usb_current_mode(void *handle, uint8_t *mode)
 {
@@ -712,7 +1131,7 @@ 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;
@@ -734,7 +1153,7 @@ 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);
@@ -742,19 +1161,19 @@ 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;
@@ -800,7 +1219,7 @@ 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;
@@ -946,7 +1365,8 @@ 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;
@@ -966,7 +1386,7 @@ 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);
@@ -1123,7 +1543,7 @@ 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;
 
@@ -1133,7 +1553,7 @@ 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);
@@ -1144,17 +1564,25 @@ 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);
 
@@ -1192,7 +1620,7 @@ 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;
@@ -1211,7 +1639,7 @@ static int stlink_usb_trace_read(void *handle, uint8_t *buf, size_t *size)
 
        assert(handle != NULL);
 
-       if (h->trace.enabled && h->version.jtag >= STLINK_TRACE_MIN_VERSION) {
+       if (h->trace.enabled && (h->version.flags & STLINK_F_HAS_TRACE)) {
                int res;
 
                stlink_usb_init_buffer(handle, h->rx_ep, 10);
@@ -1219,7 +1647,7 @@ 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;
 
@@ -1284,7 +1712,7 @@ 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;
@@ -1296,7 +1724,7 @@ 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;
@@ -1340,14 +1768,14 @@ static void stlink_usb_trace_disable(void *handle)
 
        assert(handle != NULL);
 
-       assert(h->version.jtag >= STLINK_TRACE_MIN_VERSION);
+       assert(h->version.flags & STLINK_F_HAS_TRACE);
 
        LOG_DEBUG("Tracing: disable");
 
        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;
@@ -1362,7 +1790,7 @@ static int stlink_usb_trace_enable(void *handle)
 
        assert(handle != NULL);
 
-       if (h->version.jtag >= STLINK_TRACE_MIN_VERSION) {
+       if (h->version.flags & STLINK_F_HAS_TRACE) {
                stlink_usb_init_buffer(handle, h->rx_ep, 10);
 
                h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
@@ -1372,7 +1800,7 @@ 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;
@@ -1401,7 +1829,7 @@ 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;
@@ -1426,7 +1854,7 @@ 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;
@@ -1448,7 +1876,7 @@ 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;
@@ -1469,7 +1897,7 @@ 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);
@@ -1493,20 +1921,21 @@ 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;
 }
 
 /** */
@@ -1517,17 +1946,17 @@ 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);
@@ -1551,7 +1980,7 @@ 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;
@@ -1564,25 +1993,23 @@ 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);
+       }
 }
 
 /** */
@@ -1595,9 +2022,9 @@ 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;
        }
 
@@ -1614,7 +2041,7 @@ 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;
@@ -1633,9 +2060,9 @@ 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;
        }
 
@@ -1648,7 +2075,79 @@ 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;
+
+       return stlink_usb_get_rw_status(handle);
+}
+
+/** */
+static int stlink_usb_read_mem16(void *handle, uint32_t addr, uint16_t len,
+                         uint8_t *buffer)
+{
+       int res;
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_MEM_16BIT))
+               return ERROR_COMMAND_NOTFOUND;
+
+       /* data must be a multiple of 2 and half-word aligned */
+       if (len % 2 || addr % 2) {
+               LOG_DEBUG("Invalid data alignment");
+               return ERROR_TARGET_UNALIGNED_ACCESS;
+       }
+
+       stlink_usb_init_buffer(handle, h->rx_ep, len);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READMEM_16BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
+
+       res = stlink_usb_xfer_noerrcheck(handle, h->databuf, len);
+
+       if (res != ERROR_OK)
+               return res;
+
+       memcpy(buffer, h->databuf, len);
+
+       return stlink_usb_get_rw_status(handle);
+}
+
+/** */
+static int stlink_usb_write_mem16(void *handle, uint32_t addr, uint16_t len,
+                          const uint8_t *buffer)
+{
+       int res;
+       struct stlink_usb_handle_s *h = handle;
+
+       assert(handle != NULL);
+
+       if (!(h->version.flags & STLINK_F_HAS_MEM_16BIT))
+               return ERROR_COMMAND_NOTFOUND;
+
+       /* data must be a multiple of 2 and half-word aligned */
+       if (len % 2 || addr % 2) {
+               LOG_DEBUG("Invalid data alignment");
+               return ERROR_TARGET_UNALIGNED_ACCESS;
+       }
+
+       stlink_usb_init_buffer(handle, h->tx_ep, len);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITEMEM_16BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
+
+       res = stlink_usb_xfer_noerrcheck(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
@@ -1680,7 +2179,7 @@ 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;
@@ -1714,7 +2213,7 @@ 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;
@@ -1741,10 +2240,14 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
        /* calculate byte count */
        count *= size;
 
+       /* switch to 8 bit if stlink does not support 16 bit memory read */
+       if (size == 2 && !(h->version.flags & STLINK_F_HAS_MEM_16BIT))
+               size = 1;
+
        while (count) {
 
-               bytes_remaining = (size == 4) ? \
-                               stlink_max_block_size(h->max_mem_packet, addr) : STLINK_MAX_RW8;
+               bytes_remaining = (size != 1) ? \
+                               stlink_max_block_size(h->max_mem_packet, addr) : stlink_usb_block(h);
 
                if (count < bytes_remaining)
                        bytes_remaining = count;
@@ -1754,22 +2257,26 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
                        if (retval != ERROR_OK)
                                return retval;
                } else
-               /* the stlink only supports 8/32bit memory read/writes
-                * honour 32bit, all others will be handled as 8bit access */
-               if (size == 4) {
+               /*
+                * all stlink support 8/32bit memory read/writes and only from
+                * stlink V2J26 there is support for 16 bit memory read/write.
+                * Honour 32 bit and, if possible, 16 bit too. Otherwise, handle
+                * as 8bit access.
+                */
+               if (size != 1) {
 
-                       /* When in jtag mode the stlink uses the auto-increment functinality.
+                       /* When in jtag mode the stlink uses the auto-increment functionality.
                         * However it expects us to pass the data correctly, this includes
                         * alignment and any page boundaries. We already do this as part of the
                         * adi_v5 implementation, but the stlink is a hla adapter and so this
-                        * needs implementiong manually.
+                        * needs implementing manually.
                         * currently this only affects jtag mode, according to ST they do single
                         * access in SWD mode - but this may change and so we do it for both modes */
 
                        /* we first need to check for any unaligned bytes */
-                       if (addr % 4) {
+                       if (addr & (size - 1)) {
 
-                               uint32_t head_bytes = 4 - (addr % 4);
+                               uint32_t head_bytes = size - (addr & (size - 1));
                                retval = stlink_usb_read_mem8(handle, addr, head_bytes, buffer);
                                if (retval == ERROR_WAIT && retries < MAX_WAIT_RETRIES) {
                                        usleep((1<<retries++) * 1000);
@@ -1783,8 +2290,10 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
                                bytes_remaining -= head_bytes;
                        }
 
-                       if (bytes_remaining % 4)
+                       if (bytes_remaining & (size - 1))
                                retval = stlink_usb_read_mem(handle, addr, 1, bytes_remaining, buffer);
+                       else if (size == 2)
+                               retval = stlink_usb_read_mem16(handle, addr, bytes_remaining, buffer);
                        else
                                retval = stlink_usb_read_mem32(handle, addr, bytes_remaining, buffer);
                } else
@@ -1816,10 +2325,14 @@ static int stlink_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
        /* calculate byte count */
        count *= size;
 
+       /* switch to 8 bit if stlink does not support 16 bit memory read */
+       if (size == 2 && !(h->version.flags & STLINK_F_HAS_MEM_16BIT))
+               size = 1;
+
        while (count) {
 
-               bytes_remaining = (size == 4) ? \
-                               stlink_max_block_size(h->max_mem_packet, addr) : STLINK_MAX_RW8;
+               bytes_remaining = (size != 1) ? \
+                               stlink_max_block_size(h->max_mem_packet, addr) : stlink_usb_block(h);
 
                if (count < bytes_remaining)
                        bytes_remaining = count;
@@ -1829,22 +2342,26 @@ static int stlink_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
                        if (retval != ERROR_OK)
                                return retval;
                } else
-               /* the stlink only supports 8/32bit memory read/writes
-                * honour 32bit, all others will be handled as 8bit access */
-               if (size == 4) {
+               /*
+                * all stlink support 8/32bit memory read/writes and only from
+                * stlink V2J26 there is support for 16 bit memory read/write.
+                * Honour 32 bit and, if possible, 16 bit too. Otherwise, handle
+                * as 8bit access.
+                */
+               if (size != 1) {
 
-                       /* When in jtag mode the stlink uses the auto-increment functinality.
+                       /* When in jtag mode the stlink uses the auto-increment functionality.
                         * However it expects us to pass the data correctly, this includes
                         * alignment and any page boundaries. We already do this as part of the
                         * adi_v5 implementation, but the stlink is a hla adapter and so this
-                        * needs implementiong manually.
+                        * needs implementing manually.
                         * currently this only affects jtag mode, according to ST they do single
                         * access in SWD mode - but this may change and so we do it for both modes */
 
                        /* we first need to check for any unaligned bytes */
-                       if (addr % 4) {
+                       if (addr & (size - 1)) {
 
-                               uint32_t head_bytes = 4 - (addr % 4);
+                               uint32_t head_bytes = size - (addr & (size - 1));
                                retval = stlink_usb_write_mem8(handle, addr, head_bytes, buffer);
                                if (retval == ERROR_WAIT && retries < MAX_WAIT_RETRIES) {
                                        usleep((1<<retries++) * 1000);
@@ -1858,8 +2375,10 @@ static int stlink_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
                                bytes_remaining -= head_bytes;
                        }
 
-                       if (bytes_remaining % 4)
+                       if (bytes_remaining & (size - 1))
                                retval = stlink_usb_write_mem(handle, addr, 1, bytes_remaining, buffer);
+                       else if (size == 2)
+                               retval = stlink_usb_write_mem16(handle, addr, bytes_remaining, buffer);
                        else
                                retval = stlink_usb_write_mem32(handle, addr, bytes_remaining, buffer);
 
@@ -1886,70 +2405,223 @@ static int stlink_usb_override_target(const char *targetname)
        return !strcmp(targetname, "cortex_m");
 }
 
-static int stlink_speed(void *handle, int khz, bool query)
+static int stlink_speed_swim(void *handle, int khz, bool query)
 {
-       unsigned i;
-       int speed_index = -1;
-       int speed_diff = INT_MAX;
-       struct stlink_usb_handle_s *h = handle;
-
-       if (h && (h->transport == HL_TRANSPORT_SWIM)) {
-               /*
+       /*
                        we dont care what the khz rate is
                        we only have low and high speed...
                        before changing speed the SWIM_CSR HS bit
                        must be updated
-                */
-               if (khz == 0)
-                       stlink_swim_speed(handle, 0);
-               else
-                       stlink_swim_speed(handle, 1);
-               return khz;
-       }
+        */
+       if (khz == 0)
+               stlink_swim_speed(handle, 0);
+       else
+               stlink_swim_speed(handle, 1);
+       return khz;
+}
 
-       /* only supported by stlink/v2 and for firmware >= 22 */
-       if (h && (h->version.stlink == 1 || h->version.jtag < 22))
-               return khz;
+static int stlink_match_speed_map(const struct speed_map *map, unsigned int map_size, int khz, bool query)
+{
+       unsigned int i;
+       int speed_index = -1;
+       int speed_diff = INT_MAX;
+       int last_valid_speed = -1;
+       bool match = true;
 
-       for (i = 0; i < ARRAY_SIZE(stlink_khz_to_speed_map); i++) {
-               if (khz == stlink_khz_to_speed_map[i].speed) {
+       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;
                } else {
-                       int current_diff = khz - stlink_khz_to_speed_map[i].speed;
+                       int current_diff = khz - map[i].speed;
                        /* get abs value for comparison */
                        current_diff = (current_diff > 0) ? current_diff : -current_diff;
-                       if ((current_diff < speed_diff) && khz >= stlink_khz_to_speed_map[i].speed) {
+                       if ((current_diff < speed_diff) && khz >= map[i].speed) {
                                speed_diff = current_diff;
                                speed_index = i;
                        }
                }
        }
 
-       bool match = true;
-
        if (speed_index == -1) {
                /* this will only be here if we cannot match the slow speed.
                 * use the slowest speed we support.*/
-               speed_index = ARRAY_SIZE(stlink_khz_to_speed_map) - 1;
+               speed_index = last_valid_speed;
                match = false;
-       } else if (i == ARRAY_SIZE(stlink_khz_to_speed_map))
+       } else if (i == map_size)
                match = false;
 
        if (!match && query) {
                LOG_INFO("Unable to match requested speed %d kHz, using %d kHz", \
-                               khz, stlink_khz_to_speed_map[speed_index].speed);
+                               khz, map[speed_index].speed);
        }
 
-       if (h && !query) {
-               int result = stlink_usb_set_swdclk(h, stlink_khz_to_speed_map[speed_index].speed_divisor);
+       return speed_index;
+}
+
+static int stlink_speed_swd(void *handle, int khz, bool query)
+{
+       int speed_index;
+       struct stlink_usb_handle_s *h = handle;
+
+       /* old firmware cannot change it */
+       if (!(h->version.flags & STLINK_F_HAS_SWD_SET_FREQ))
+               return khz;
+
+       speed_index = stlink_match_speed_map(stlink_khz_to_speed_map_swd,
+               ARRAY_SIZE(stlink_khz_to_speed_map_swd), khz, query);
+
+       if (!query) {
+               int result = stlink_usb_set_swdclk(h, stlink_khz_to_speed_map_swd[speed_index].speed_divisor);
+               if (result != ERROR_OK) {
+                       LOG_ERROR("Unable to set adapter speed");
+                       return khz;
+               }
+       }
+
+       return stlink_khz_to_speed_map_swd[speed_index].speed;
+}
+
+static int stlink_speed_jtag(void *handle, int khz, bool query)
+{
+       int speed_index;
+       struct stlink_usb_handle_s *h = handle;
+
+       /* old firmware cannot change it */
+       if (!(h->version.flags & STLINK_F_HAS_JTAG_SET_FREQ))
+               return khz;
+
+       speed_index = stlink_match_speed_map(stlink_khz_to_speed_map_jtag,
+               ARRAY_SIZE(stlink_khz_to_speed_map_jtag), khz, query);
+
+       if (!query) {
+               int result = stlink_usb_set_jtagclk(h, stlink_khz_to_speed_map_jtag[speed_index].speed_divisor);
+               if (result != ERROR_OK) {
+                       LOG_ERROR("Unable to set adapter speed");
+                       return khz;
+               }
+       }
+
+       return stlink_khz_to_speed_map_jtag[speed_index].speed;
+}
+
+void stlink_dump_speed_map(const struct speed_map *map, unsigned int map_size)
+{
+       unsigned int i;
+
+       LOG_DEBUG("Supported clock speeds are:");
+       for (i = 0; i < map_size; i++)
+               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;
+}
 
-       return stlink_khz_to_speed_map[speed_index].speed;
+static int stlink_speed(void *handle, int khz, bool query)
+{
+       struct stlink_usb_handle_s *h = handle;
+
+       if (!handle)
+               return khz;
+
+       switch (h->transport) {
+       case HL_TRANSPORT_SWIM:
+               return stlink_speed_swim(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;
 }
 
 /** */
@@ -2005,7 +2677,6 @@ 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");
 
@@ -2060,9 +2731,17 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
                        case STLINK_V1_PID:
                                h->version.stlink = 1;
                                h->tx_ep = STLINK_TX_EP;
-                               h->trace_ep = STLINK_TRACE_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;
                                h->tx_ep = STLINK_V2_1_TX_EP;
                                h->trace_ep = STLINK_V2_1_TRACE_EP;
@@ -2113,6 +2792,9 @@ 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 == STLINK_JTAG_API_V1)
+                               err = ERROR_FAIL;
+                       /* fall-through */
                case HL_TRANSPORT_JTAG:
                        if (h->version.jtag == 0)
                                err = ERROR_FAIL;
@@ -2131,13 +2813,6 @@ 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);
 
@@ -2157,13 +2832,23 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
                return ERROR_OK;
        }
 
-       /* clock speed only supported by stlink/v2 and for firmware >= 22 */
-       if (h->version.stlink >= 2 && h->version.jtag >= 22) {
-               LOG_DEBUG("Supported clock speeds are:");
+       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);
+               }
+       }
 
-               for (unsigned i = 0; i < ARRAY_SIZE(stlink_khz_to_speed_map); i++)
-                       LOG_DEBUG("%d kHz", stlink_khz_to_speed_map[i].speed);
+       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, param->initial_interface_speed, false);
        }
 
@@ -2194,12 +2879,13 @@ error_open:
        return ERROR_FAIL;
 }
 
-int stlink_config_trace(void *handle, bool enabled, enum tpio_pin_protocol pin_protocol,
+int stlink_config_trace(void *handle, bool enabled, enum tpiu_pin_protocol pin_protocol,
                        uint32_t port_size, unsigned int *trace_freq)
 {
        struct stlink_usb_handle_s *h = handle;
 
-       if (enabled && (h->jtag_api < 2 || pin_protocol != ASYNC_UART)) {
+       if (enabled && (!(h->version.flags & STLINK_F_HAS_TRACE) ||
+                       pin_protocol != TPIU_PIN_PROTOCOL_ASYNC_UART)) {
                LOG_ERROR("The attached ST-LINK version doesn't support this trace mode");
                return ERROR_FAIL;
        }