use COMMAND_HANDLER macro to define all commands
[fw/openocd] / src / jtag / vsllink.c
index de4220f798af8a38b6697ce73c2f478e60e3960b..decca16c61eecb1fad46c6a35696d922309f2859 100644 (file)
 #include "config.h"
 #endif
 
-#include "replacements.h"
-
-#include "jtag.h"
+#include "interface.h"
+#include "commands.h"
 
 #include <usb.h>
-#include <string.h>
 
-#include "log.h"
 
 //#define _VSLLINK_IN_DEBUG_MODE_
 
-/* enable this to view USB communication
- */
-#if 0
-#define _DEBUG_USB_COMMS_
-#endif
-
-#ifdef _DEBUG_JTAG_IO_
-#define DEBUG_JTAG_IO(expr ...)        LOG_DEBUG(expr)
-#else
-#define DEBUG_JTAG_IO(expr ...)
-#endif
-
-u16 vsllink_vid;
-u16 vsllink_pid;
-u8 vsllink_bulkout;
-u8 vsllink_bulkin;
+#define VSLLINK_MODE_NORMAL                    0
+#define VSLLINK_MODE_DMA                       1
 
-#define VSLLINK_USB_TIMEOUT                    5000
+static uint16_t vsllink_usb_vid;
+static uint16_t vsllink_usb_pid;
+static uint8_t vsllink_usb_bulkout;
+static uint8_t vsllink_usb_bulkin;
+static uint8_t vsllink_usb_interface;
+static uint8_t vsllink_mode = VSLLINK_MODE_NORMAL;
+static int VSLLINK_USB_TIMEOUT = 10000;
 
 static int VSLLINK_BufferSize = 1024;
 
 /* Global USB buffers */
 static int vsllink_usb_out_buffer_idx;
 static int vsllink_usb_in_want_length;
-static u8* vsllink_usb_in_buffer = NULL;
-static u8* vsllink_usb_out_buffer = NULL;
+static uint8_t* vsllink_usb_in_buffer = NULL;
+static uint8_t* vsllink_usb_out_buffer = NULL;
 
 /* Constants for VSLLink command */
 #define VSLLINK_CMD_CONN                       0x80
@@ -74,9 +63,10 @@ static u8* vsllink_usb_out_buffer = NULL;
 #define VSLLINK_CMD_HW_JTAGSEQCMD      0xA0
 #define VSLLINK_CMD_HW_JTAGHLCMD       0xA1
 #define VSLLINK_CMD_HW_SWDCMD          0xA2
+#define VSLLINK_CMD_HW_JTAGRAWCMD      0xA3
 
 #define VSLLINK_CMDJTAGSEQ_TMSBYTE     0x00
-#define VSLLINK_CMDJTAGSEQ_TMS0BYTE    0x40
+#define VSLLINK_CMDJTAGSEQ_TMSCLOCK    0x40
 #define VSLLINK_CMDJTAGSEQ_SCAN                0x80
 
 #define VSLLINK_CMDJTAGSEQ_CMDMSK      0xC0
@@ -92,7 +82,7 @@ static u8* vsllink_usb_out_buffer = NULL;
 #define JTAG_PINMSK_TDO                                (1 << 7)
 
 
-#define VSLLINK_TAP_MOVE(from, to) VSLLINK_tap_move[tap_move_map[from]][tap_move_map[to]]
+#define VSLLINK_TAP_MOVE(from, to)     VSLLINK_tap_move[tap_move_ndx(from)][tap_move_ndx(to)]
 
 /* VSLLINK_tap_move[i][j]: tap movement command to go from state i to state j
  * 0: Test-Logic-Reset
@@ -101,18 +91,18 @@ static u8* vsllink_usb_out_buffer = NULL;
  * 3: Pause-DR
  * 4: Shift-IR
  * 5: Pause-IR
- * 
+ *
  * SD->SD and SI->SI have to be caught in interface specific code
  */
-u8 VSLLINK_tap_move[6][6] =
+static uint8_t VSLLINK_tap_move[6][6] =
 {
 /*       TLR   RTI   SD    PD    SI    PI             */
        {0xff, 0x7f, 0x2f, 0x0a, 0x37, 0x16},   /* TLR */
        {0xff, 0x00, 0x45, 0x05, 0x4b, 0x0b},   /* RTI */
        {0xff, 0x61, 0x00, 0x01, 0x0f, 0x2f},   /* SD  */
-       {0xff, 0x60, 0x40, 0x5c, 0x3c, 0x5e},   /* PD  */
+       {0xfe, 0x60, 0x40, 0x5c, 0x3c, 0x5e},   /* PD  */
        {0xff, 0x61, 0x07, 0x17, 0x00, 0x01},   /* SI  */
-       {0xff, 0x60, 0x38, 0x5c, 0x40, 0x5e}    /* PI  */
+       {0xfe, 0x60, 0x38, 0x5c, 0x40, 0x5e}    /* PI  */
 };
 
 typedef struct insert_insignificant_operation
@@ -121,7 +111,7 @@ typedef struct insert_insignificant_operation
        unsigned char insert_position;
 }insert_insignificant_operation_t;
 
-insert_insignificant_operation_t VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[6][6] =
+static insert_insignificant_operation_t VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[6][6] =
 {
 /*      stuff  offset   */
        {/*     TLR     */
@@ -168,17 +158,17 @@ insert_insignificant_operation_t VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[6][6] =
        {0,             0,}},   /* PI  */
 };
 
-u8 VSLLINK_BIT_MSK[8] =
+static uint8_t VSLLINK_BIT_MSK[8] =
 {
        0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f
 };
 
 typedef struct
 {
-       int length; /* Number of bits to read */
        int offset;
+       int length; /* Number of bits to read */
        scan_command_t *command; /* Corresponding scan command */
-       u8 *buffer;
+       uint8_t *buffer;
 } pending_scan_result_t;
 
 #define MAX_PENDING_SCAN_RESULTS 256
@@ -186,35 +176,39 @@ typedef struct
 static int pending_scan_results_length;
 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 
-/* External interface functions */
-int vsllink_execute_queue(void);
-int vsllink_speed(int speed);
-int vsllink_khz(int khz, int *jtag_speed);
-int vsllink_speed_div(int jtag_speed, int *khz);
-int vsllink_register_commands(struct command_context_s *cmd_ctx);
-int vsllink_init(void);
-int vsllink_quit(void);
-
-/* CLI command handler functions */
-int vsllink_handle_usb_vid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int vsllink_handle_usb_pid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int vsllink_handle_usb_bulkin_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int vsllink_handle_usb_bulkout_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-
 /* Queue command functions */
-void vsllink_end_state(enum tap_state state);
-void vsllink_state_move(void);
-void vsllink_path_move(int num_states, enum tap_state *path);
-void vsllink_runtest(int num_cycles);
-void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command);
-void vsllink_reset(int trst, int srst);
-void vsllink_simple_command(u8 command);
+static void vsllink_end_state(tap_state_t state);
+static void vsllink_state_move_dma(void);
+static void vsllink_state_move_normal(void);
+static void (*vsllink_state_move)(void);
+static void vsllink_path_move_dma(int num_states, tap_state_t *path);
+static void vsllink_path_move_normal(int num_states, tap_state_t *path);
+static void (*vsllink_path_move)(int num_states, tap_state_t *path);
+static void vsllink_runtest(int num_cycles);
+static void vsllink_stableclocks_dma(int num_cycles, int tms);
+static void vsllink_stableclocks_normal(int num_cycles, int tms);
+static void (*vsllink_stableclocks)(int num_cycles, int tms);
+static void vsllink_scan_dma(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command);
+static void vsllink_scan_normal(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command);
+static void (*vsllink_scan)(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command);
+static void vsllink_reset(int trst, int srst);
+static void vsllink_simple_command(uint8_t command);
+static int vsllink_connect(void);
+static int vsllink_disconnect(void);
 
 /* VSLLink tap buffer functions */
-void vsllink_tap_init(void);
-int vsllink_tap_execute(void);
-void vsllink_tap_ensure_space(int scans, int bytes);
-void vsllink_tap_append_scan(int length, u8 *buffer, scan_command_t *command, int offset);
+static void vsllink_tap_append_step(int tms, int tdi);
+static void vsllink_tap_init_dma(void);
+static void vsllink_tap_init_normal(void);
+static void (*vsllink_tap_init)(void);
+static int vsllink_tap_execute_dma(void);
+static int vsllink_tap_execute_normal(void);
+static int (*vsllink_tap_execute)(void);
+static void vsllink_tap_ensure_space_dma(int scans, int length);
+static void vsllink_tap_ensure_space_normal(int scans, int length);
+static void (*vsllink_tap_ensure_space)(int scans, int length);
+static void vsllink_tap_append_scan_dma(int length, uint8_t *buffer, scan_command_t *command);
+static void vsllink_tap_append_scan_normal(int length, uint8_t *buffer, scan_command_t *command, int offset);
 
 /* VSLLink lowlevel functions */
 typedef struct vsllink_jtag
@@ -222,101 +216,89 @@ typedef struct vsllink_jtag
        struct usb_dev_handle* usb_handle;
 } vsllink_jtag_t;
 
-vsllink_jtag_t *vsllink_usb_open(void);
-void vsllink_usb_close(vsllink_jtag_t *vsllink_jtag);
-int vsllink_usb_message(vsllink_jtag_t *vsllink_jtag, int out_length, int in_length);
-int vsllink_usb_write(vsllink_jtag_t *vsllink_jtag, int out_length);
-int vsllink_usb_read(vsllink_jtag_t *vsllink_jtag);
+static vsllink_jtag_t *vsllink_usb_open(void);
+static void vsllink_usb_close(vsllink_jtag_t *vsllink_jtag);
+static int vsllink_usb_message(vsllink_jtag_t *vsllink_jtag, int out_length, int in_length);
+static int vsllink_usb_write(vsllink_jtag_t *vsllink_jtag, int out_length);
+static int vsllink_usb_read(vsllink_jtag_t *vsllink_jtag);
 
-void vsllink_debug_buffer(u8 *buffer, int length);
+#if defined _DEBUG_USB_COMMS_ || defined _DEBUG_JTAG_IO_
+static void vsllink_debug_buffer(uint8_t *buffer, int length);
+#endif
 
 static int vsllink_tms_data_len = 0;
-static u8* vsllink_tms_cmd_pos;
+static uint8_t* vsllink_tms_cmd_pos;
 
-vsllink_jtag_t* vsllink_jtag_handle;
+static int tap_length = 0;
+static int tap_buffer_size = 0;
+static uint8_t *tms_buffer = NULL;
+static uint8_t *tdi_buffer = NULL;
+static uint8_t *tdo_buffer = NULL;
+static int last_tms;
 
-/***************************************************************************/
-/* External interface implementation */
+static vsllink_jtag_t* vsllink_jtag_handle = NULL;
 
-jtag_interface_t vsllink_interface =
+static void reset_command_pointer(void)
 {
-       .name = "vsllink",
-       .execute_queue = vsllink_execute_queue,
-       .speed = vsllink_speed,
-       .khz = vsllink_khz,
-       .speed_div = vsllink_speed_div,
-       .register_commands = vsllink_register_commands,
-       .init = vsllink_init,
-       .quit = vsllink_quit
-};
+       if (vsllink_mode == VSLLINK_MODE_NORMAL)
+       {
+               vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGSEQCMD;
+               vsllink_usb_out_buffer_idx = 3;
+       }
+       else
+       {
+               tap_length = 0;
+       }
+}
 
-int vsllink_execute_queue(void)
+static int vsllink_execute_queue(void)
 {
        jtag_command_t *cmd = jtag_command_queue;
        int scan_size;
        enum scan_type type;
-       u8 *buffer;
+       uint8_t *buffer;
 
-       DEBUG_JTAG_IO("--------------------------------------------------------------------------------");
+       DEBUG_JTAG_IO("--------------------------------- vsllink -------------------------------------");
 
-       vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGSEQCMD;
-       vsllink_usb_out_buffer_idx = 3;
+       reset_command_pointer();
        while (cmd != NULL)
        {
                switch (cmd->type)
                {
-                       case JTAG_END_STATE:
-                               DEBUG_JTAG_IO("end_state: %s", jtag_state_name(cmd->cmd.end_state->end_state));
-                       
-                               if (cmd->cmd.end_state->end_state != -1)
-                               {
-                                       vsllink_end_state(cmd->cmd.end_state->end_state);
-                               }
-                               break;
-       
                        case JTAG_RUNTEST:
-                               DEBUG_JTAG_IO( "runtest %i cycles, end in %s", cmd->cmd.runtest->num_cycles, \
-                                       jtag_state_name(cmd->cmd.runtest->end_state));
+                               DEBUG_JTAG_IO("runtest %i cycles, end in %s", cmd->cmd.runtest->num_cycles, \
+                                       tap_state_name(cmd->cmd.runtest->end_state));
 
-                               if (cmd->cmd.runtest->end_state != -1)
-                               {
-                                       vsllink_end_state(cmd->cmd.runtest->end_state);
-                               }
+                               vsllink_end_state(cmd->cmd.runtest->end_state);
                                vsllink_runtest(cmd->cmd.runtest->num_cycles);
                                break;
-       
+
                        case JTAG_STATEMOVE:
-                               DEBUG_JTAG_IO("statemove end in %s", jtag_state_name(cmd->cmd.statemove->end_state));
-                       
-                               if (cmd->cmd.statemove->end_state != -1)
-                               {
-                                       vsllink_end_state(cmd->cmd.statemove->end_state);
-                               }
+                               DEBUG_JTAG_IO("statemove end in %s", tap_state_name(cmd->cmd.statemove->end_state));
+
+                               vsllink_end_state(cmd->cmd.statemove->end_state);
                                vsllink_state_move();
                                break;
-       
+
                        case JTAG_PATHMOVE:
                                DEBUG_JTAG_IO("pathmove: %i states, end in %s", \
                                        cmd->cmd.pathmove->num_states, \
-                                       jtag_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
-                       
+                                       tap_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
+
                                vsllink_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
                                break;
-       
+
                        case JTAG_SCAN:
-                               if (cmd->cmd.scan->end_state != -1)
-                               {
-                                       vsllink_end_state(cmd->cmd.scan->end_state);
-                               }
-                       
+                               vsllink_end_state(cmd->cmd.scan->end_state);
+
                                scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
                                if (cmd->cmd.scan->ir_scan)
                                {
-                                       DEBUG_JTAG_IO("JTAG Scan write IR(%d bits), end in %s:", scan_size, jtag_state_name(cmd->cmd.scan->end_state));
+                                       DEBUG_JTAG_IO("JTAG Scan write IR(%d bits), end in %s:", scan_size, tap_state_name(cmd->cmd.scan->end_state));
                                }
                                else
                                {
-                                       DEBUG_JTAG_IO("JTAG Scan write DR(%d bits), end in %s:", scan_size, jtag_state_name(cmd->cmd.scan->end_state));
+                                       DEBUG_JTAG_IO("JTAG Scan write DR(%d bits), end in %s:", scan_size, tap_state_name(cmd->cmd.scan->end_state));
                                }
 
 #ifdef _DEBUG_JTAG_IO_
@@ -327,48 +309,69 @@ int vsllink_execute_queue(void)
 
                                vsllink_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
                                break;
-       
+
                        case JTAG_RESET:
                                DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 
                                vsllink_tap_execute();
-                       
+
                                if (cmd->cmd.reset->trst == 1)
                                {
-                                       cur_state = TAP_RESET;
+                                       tap_set_state(TAP_RESET);
                                }
                                vsllink_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
-
-                               vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGSEQCMD;
-                               vsllink_usb_out_buffer_idx = 3;
                                break;
-       
+
                        case JTAG_SLEEP:
                                DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
                                vsllink_tap_execute();
                                jtag_sleep(cmd->cmd.sleep->us);
                                break;
-       
+
+                       case JTAG_STABLECLOCKS:
+                               DEBUG_JTAG_IO("add %d clocks", cmd->cmd.stableclocks->num_cycles);
+                               switch (tap_get_state())
+                               {
+                               case TAP_RESET:
+                                       // tms should be '1' to stay in TAP_RESET mode
+                                       scan_size = 1;
+                                       break;
+                               case TAP_DRSHIFT:
+                               case TAP_IDLE:
+                               case TAP_DRPAUSE:
+                               case TAP_IRSHIFT:
+                               case TAP_IRPAUSE:
+                                       // in other mode, tms should be '0'
+                                       scan_size = 0;
+                                       break;                  /* above stable states are OK */
+                               default:
+                                        LOG_ERROR("jtag_add_clocks() was called with TAP in non-stable state \"%s\"",
+                                                        tap_state_name(tap_get_state()));
+                                        exit(-1);
+                               }
+                               vsllink_stableclocks(cmd->cmd.stableclocks->num_cycles, scan_size);
+                               break;
+
                        default:
-                               LOG_ERROR("BUG: unknown JTAG command type encountered");
+                               LOG_ERROR("BUG: unknown JTAG command type encountered: %d", cmd->type);
                                exit(-1);
                }
                cmd = cmd->next;
        }
-       
+
        return vsllink_tap_execute();
 }
 
-int vsllink_speed(int speed)
+static int vsllink_speed(int speed)
 {
        int result;
 
        vsllink_usb_out_buffer[0] = VSLLINK_CMD_SET_SPEED;
        vsllink_usb_out_buffer[1] = (speed >> 0) & 0xff;
        vsllink_usb_out_buffer[2] = (speed >> 8) & 0xFF;
-               
+
        result = vsllink_usb_write(vsllink_jtag_handle, 3);
-               
+
        if (result == 3)
        {
                return ERROR_OK;
@@ -378,41 +381,27 @@ int vsllink_speed(int speed)
                LOG_ERROR("VSLLink setting speed failed (%d)", result);
                return ERROR_JTAG_DEVICE_ERROR;
        }
-       
-       return ERROR_OK;
-}
 
-int vsllink_khz(int khz, int *jtag_speed)
-{
-       *jtag_speed = khz;
-       
        return ERROR_OK;
 }
 
-int vsllink_speed_div(int jtag_speed, int *khz)
+static int vsllink_khz(int khz, int *jtag_speed)
 {
-       *khz = jtag_speed;
+       *jtag_speed = khz;
 
        return ERROR_OK;
 }
 
-int vsllink_register_commands(struct command_context_s *cmd_ctx)
+static int vsllink_speed_div(int jtag_speed, int *khz)
 {
-       register_command(cmd_ctx, NULL, "vsllink_usb_vid", vsllink_handle_usb_vid_command, 
-                                       COMMAND_CONFIG, NULL);
-       register_command(cmd_ctx, NULL, "vsllink_usb_pid", vsllink_handle_usb_pid_command, 
-                                       COMMAND_CONFIG, NULL);
-       register_command(cmd_ctx, NULL, "vsllink_usb_bulkin", vsllink_handle_usb_bulkin_command, 
-                                       COMMAND_CONFIG, NULL);
-       register_command(cmd_ctx, NULL, "vsllink_usb_bulkout", vsllink_handle_usb_bulkout_command, 
-                                       COMMAND_CONFIG, NULL);
+       *khz = jtag_speed;
 
        return ERROR_OK;
 }
 
-int vsllink_init(void)
+static int vsllink_init(void)
 {
-       int check_cnt;  
+       int check_cnt, to_tmp;
        int result;
        char version_str[100];
 
@@ -425,17 +414,20 @@ int vsllink_init(void)
        }
 
        vsllink_jtag_handle = vsllink_usb_open();
-       
+
        if (vsllink_jtag_handle == 0)
        {
                LOG_ERROR("Can't find USB JTAG Interface! Please check connection and permissions.");
                return ERROR_JTAG_INIT_FAILED;
        }
-               
+       LOG_DEBUG("vsllink found on %04X:%04X", vsllink_usb_vid, vsllink_usb_pid);
+
+       to_tmp = VSLLINK_USB_TIMEOUT;
+       VSLLINK_USB_TIMEOUT = 100;
        check_cnt = 0;
-       while (check_cnt < 3)
+       while (check_cnt < 5)
        {
-               vsllink_simple_command(VSLLINK_CMD_CONN);
+               vsllink_simple_command(0x00);
                result = vsllink_usb_read(vsllink_jtag_handle);
 
                if (result > 2)
@@ -443,7 +435,7 @@ int vsllink_init(void)
                        vsllink_usb_in_buffer[result] = 0;
                        VSLLINK_BufferSize = vsllink_usb_in_buffer[0] + (vsllink_usb_in_buffer[1] << 8);
                        strncpy(version_str, (char *)vsllink_usb_in_buffer + 2, sizeof(version_str));
-                       LOG_INFO(version_str);
+                       LOG_INFO("%s", version_str);
 
                        // free the pre-alloc memroy
                        free(vsllink_usb_in_buffer);
@@ -463,19 +455,63 @@ int vsllink_init(void)
                        {
                                LOG_INFO("buffer size for USB is %d bytes", VSLLINK_BufferSize);
                        }
+                       // alloc memory for dma mode
+                       if (vsllink_mode == VSLLINK_MODE_DMA)
+                       {
+                               tap_buffer_size = (VSLLINK_BufferSize - 3) / 2;
+                               tms_buffer = (uint8_t*)malloc(tap_buffer_size);
+                               tdi_buffer = (uint8_t*)malloc(tap_buffer_size);
+                               tdo_buffer = (uint8_t*)malloc(tap_buffer_size);
+                               if ((tms_buffer == NULL) || (tdi_buffer == NULL) || (tdo_buffer == NULL))
+                               {
+                                       LOG_ERROR("Not enough memory");
+                                       exit(-1);
+                               }
+                       }
                        break;
                }
                vsllink_simple_command(VSLLINK_CMD_DISCONN);
-
                check_cnt++;
        }
-
        if (check_cnt == 3)
        {
                // It's dangerout to proced
                LOG_ERROR("VSLLink initial failed");
                exit(-1);
        }
+       VSLLINK_USB_TIMEOUT = to_tmp;
+
+       // connect to vsllink
+       vsllink_connect();
+       // initialize function pointers
+       if (vsllink_mode == VSLLINK_MODE_NORMAL)
+       {
+               // normal mode
+               vsllink_state_move = vsllink_state_move_normal;
+               vsllink_path_move = vsllink_path_move_normal;
+               vsllink_stableclocks = vsllink_stableclocks_normal;
+               vsllink_scan = vsllink_scan_normal;
+
+               vsllink_tap_init = vsllink_tap_init_normal;
+               vsllink_tap_execute = vsllink_tap_execute_normal;
+               vsllink_tap_ensure_space = vsllink_tap_ensure_space_normal;
+
+               LOG_INFO("vsllink run in NORMAL mode");
+       }
+       else
+       {
+               // dma mode
+               vsllink_state_move = vsllink_state_move_dma;
+               vsllink_path_move = vsllink_path_move_dma;
+               vsllink_stableclocks = vsllink_stableclocks_dma;
+               vsllink_scan = vsllink_scan_dma;
+
+               vsllink_tap_init = vsllink_tap_init_dma;
+               vsllink_tap_execute = vsllink_tap_execute_dma;
+               vsllink_tap_ensure_space = vsllink_tap_ensure_space_dma;
+
+               LOG_INFO("vsllink run in DMA mode");
+       }
 
        // Set SRST and TRST to output, Set USR1 and USR2 to input
        vsllink_usb_out_buffer[0] = VSLLINK_CMD_SET_PORTDIR;
@@ -492,11 +528,11 @@ int vsllink_init(void)
        LOG_INFO("VSLLink JTAG Interface ready");
 
        vsllink_tap_init();
-       
+
        return ERROR_OK;
 }
 
-int vsllink_quit(void)
+static int vsllink_quit(void)
 {
        if ((vsllink_usb_in_buffer != NULL) && (vsllink_usb_out_buffer != NULL))
        {
@@ -511,29 +547,59 @@ int vsllink_quit(void)
                }
 
                // disconnect
-               vsllink_simple_command(VSLLINK_CMD_DISCONN);
+               vsllink_disconnect();
                vsllink_usb_close(vsllink_jtag_handle);
+               vsllink_jtag_handle = NULL;
        }
 
        if (vsllink_usb_in_buffer != NULL)
        {
                free(vsllink_usb_in_buffer);
+               vsllink_usb_in_buffer = NULL;
        }
        if (vsllink_usb_out_buffer != NULL)
        {
                free(vsllink_usb_out_buffer);
+               vsllink_usb_out_buffer = NULL;
+       }
+
+       return ERROR_OK;
+}
+
+/***************************************************************************/
+/* Queue command implementations */
+static int vsllink_disconnect(void)
+{
+       vsllink_simple_command(VSLLINK_CMD_DISCONN);
+       return ERROR_OK;
+}
+
+static int vsllink_connect(void)
+{
+       char vsllink_str[100];
+
+       vsllink_usb_out_buffer[0] = VSLLINK_CMD_CONN;
+       vsllink_usb_out_buffer[1] = vsllink_mode;
+       vsllink_usb_message(vsllink_jtag_handle, 2, 0);
+       if (vsllink_usb_read(vsllink_jtag_handle) > 2)
+       {
+               strncpy(vsllink_str, (char *)vsllink_usb_in_buffer + 2, sizeof(vsllink_str));
+               LOG_INFO("%s", vsllink_str);
        }
+
        return ERROR_OK;
 }
 
 // when vsllink_tms_data_len > 0, vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] is the byte that need to be appended.
 // length of VSLLINK_CMDJTAGSEQ_TMSBYTE has been set, no need to set it here.
-void vsllink_append_tms(void)
+static void vsllink_append_tms(void)
 {
-       u8 tms_scan = VSLLINK_TAP_MOVE(cur_state, end_state);
-       u16 tms2;
+       uint8_t tms_scan = VSLLINK_TAP_MOVE(tap_get_state(), tap_get_end_state());
+       uint16_t tms2;
+       insert_insignificant_operation_t *insert = \
+               &VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_ndx(tap_get_state())][tap_move_ndx(tap_get_end_state())];
 
-       if (((cur_state != TAP_RESET) && (cur_state != TAP_IDLE) && (cur_state != TAP_DRPAUSE) && (cur_state != TAP_IRPAUSE)) || \
+       if (((tap_get_state() != TAP_RESET) && (tap_get_state() != TAP_IDLE) && (tap_get_state() != TAP_DRPAUSE) && (tap_get_state() != TAP_IRPAUSE)) || \
                        (vsllink_tms_data_len <= 0) || (vsllink_tms_data_len >= 8) || \
                        (vsllink_tms_cmd_pos == NULL))
        {
@@ -541,15 +607,15 @@ void vsllink_append_tms(void)
                exit(-1);
        }
 
-       tms2 = (tms_scan & VSLLINK_BIT_MSK[VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_map[cur_state]][tap_move_map[end_state]].insert_position]) << \
+       tms2 = (tms_scan & VSLLINK_BIT_MSK[insert->insert_position]) << \
                                vsllink_tms_data_len;
-       if (VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_map[cur_state]][tap_move_map[end_state]].insert_value == 1)
+       if (insert->insert_value == 1)
        {
                tms2 |= VSLLINK_BIT_MSK[8 - vsllink_tms_data_len] << \
-                               (vsllink_tms_data_len + VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_map[cur_state]][tap_move_map[end_state]].insert_position);
+                               (vsllink_tms_data_len + insert->insert_position);
        }
-       tms2 |= (tms_scan >> VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_map[cur_state]][tap_move_map[end_state]].insert_position) << \
-                               (8 + VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_map[cur_state]][tap_move_map[end_state]].insert_position);
+       tms2 |= (tms_scan >> insert->insert_position) << \
+                               (8 + insert->insert_position);
 
        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (tms2 >> 0) & 0xff;
        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tms2 >> 8) & 0xff;
@@ -558,14 +624,11 @@ void vsllink_append_tms(void)
        vsllink_tms_cmd_pos = NULL;
 }
 
-/***************************************************************************/
-/* Queue command implementations */
-
-void vsllink_end_state(enum tap_state state)
+static void vsllink_end_state(tap_state_t state)
 {
-       if (tap_move_map[state] != -1)
+       if (tap_is_state_stable(state))
        {
-               end_state = state;
+               tap_set_end_state(state);
        }
        else
        {
@@ -575,7 +638,7 @@ void vsllink_end_state(enum tap_state state)
 }
 
 /* Goes to the end state. */
-void vsllink_state_move(void)
+static void vsllink_state_move_normal(void)
 {
        if (vsllink_tms_data_len > 0)
        {
@@ -586,14 +649,60 @@ void vsllink_state_move(void)
                vsllink_tap_ensure_space(0, 2);
 
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSBYTE;
-               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(cur_state, end_state);
+               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(tap_get_state(), tap_get_end_state());
+       }
+
+       tap_set_state(tap_get_end_state());
+}
+static void vsllink_state_move_dma(void)
+{
+       int i, insert_length = (tap_length % 8) ? (8 - (tap_length % 8)) : 0;
+       insert_insignificant_operation_t *insert = \
+               &VSLLINK_TAP_MOVE_INSERT_INSIGNIFICANT[tap_move_ndx(tap_get_state())][tap_move_ndx(tap_get_end_state())];
+       uint8_t tms_scan = VSLLINK_TAP_MOVE(tap_get_state(), tap_get_end_state());
+
+       if (tap_get_state() == TAP_RESET)
+       {
+               vsllink_tap_ensure_space(0, 8);
+
+               for (i = 0; i < 8; i++)
+               {
+                       vsllink_tap_append_step(1, 0);
+               }
+       }
+
+       if (insert_length > 0)
+       {
+               vsllink_tap_ensure_space(0, 16);
+
+               for (i = 0; i < insert->insert_position; i++)
+               {
+                       vsllink_tap_append_step((tms_scan >> i) & 1, 0);
+               }
+               for (i = 0; i < insert_length; i++)
+               {
+                       vsllink_tap_append_step(insert->insert_value, 0);
+               }
+               for (i = insert->insert_position; i < 8; i++)
+               {
+                       vsllink_tap_append_step((tms_scan >> i) & 1, 0);
+               }
+       }
+       else
+       {
+               vsllink_tap_ensure_space(0, 8);
+
+               for (i = 0; i < 8; i++)
+               {
+                       vsllink_tap_append_step((tms_scan >> i) & 1, 0);
+               }
        }
 
-       cur_state = end_state;
+       tap_set_state(tap_get_end_state());
 }
 
 // write tms from current vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx]
-void vsllink_add_path(int start, int num, enum tap_state *path)
+static void vsllink_add_path(int start, int num, tap_state_t *path)
 {
        int i;
 
@@ -608,20 +717,20 @@ void vsllink_add_path(int start, int num, enum tap_state *path)
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = 0;
                }
 
-               if (path[i - start] == tap_transitions[cur_state].high)
+               if (path[i - start] == tap_state_transition(tap_get_state(), true))
                {
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] |= 1 << (i & 7);
                }
-               else if (path[i - start] == tap_transitions[cur_state].low)
+               else if (path[i - start] == tap_state_transition(tap_get_state(), false))
                {
                        // nothing to do
                }
                else
                {
-                       LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", jtag_state_name(cur_state), jtag_state_name(path[i]));
+                       LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
                        exit(-1);
                }
-               cur_state = path[i - start];
+               tap_set_state(path[i - start]);
        }
        if ((i > 0) && ((i & 7) == 0))
        {
@@ -629,10 +738,10 @@ void vsllink_add_path(int start, int num, enum tap_state *path)
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = 0;
        }
 
-       end_state = cur_state;
+       tap_set_end_state(tap_get_state());
 }
 
-void vsllink_path_move(int num_states, enum tap_state *path)
+static void vsllink_path_move_normal(int num_states, tap_state_t *path)
 {
        int i, tms_len, tms_cmd_pos, path_idx = 0;
 
@@ -751,92 +860,153 @@ void vsllink_path_move(int num_states, enum tap_state *path)
                }
        }
 }
-
-void vsllink_runtest(int num_cycles)
+static void vsllink_path_move_dma(int num_states, tap_state_t *path)
 {
-       int tms_len;
-       enum tap_state saved_end_state = end_state;
+       int i, j = 0;
 
-       if (cur_state != TAP_IDLE)
+       if (tap_length & 7)
        {
-               // enter into IDLE state
-               vsllink_end_state(TAP_IDLE);
-               vsllink_state_move();
+               if ((8 - (tap_length & 7)) < num_states)
+               {
+                       j = 8 - (tap_length & 7);
+               }
+               else
+               {
+                       j = num_states;
+               }
+               for (i = 0; i < j; i++)
+               {
+                       if (path[i] == tap_state_transition(tap_get_state(), false))
+                       {
+                               vsllink_tap_append_step(0, 0);
+                       }
+                       else if (path[i] == tap_state_transition(tap_get_state(), true))
+                       {
+                               vsllink_tap_append_step(1, 0);
+                       }
+                       else
+                       {
+                               LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
+                               exit(-1);
+                       }
+                       tap_set_state(path[i]);
+               }
+               num_states -= j;
        }
-       else
+
+       if (num_states > 0)
        {
-               // cur_state == TAP_IDLE
-               if (vsllink_tms_data_len > 0)
+               vsllink_tap_ensure_space(0, num_states);
+
+               for (i = 0; i < num_states; i++)
+               {
+                       if (path[j + i] == tap_state_transition(tap_get_state(), false))
+                       {
+                               vsllink_tap_append_step(0, 0);
+                       }
+                       else if (path[j + i] == tap_state_transition(tap_get_state(), true))
+                       {
+                               vsllink_tap_append_step(1, 0);
+                       }
+                       else
+                       {
+                               LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
+                               exit(-1);
+                       }
+                       tap_set_state(path[j + i]);
+               }
+       }
+
+       tap_set_end_state(tap_get_state());
+}
+
+static void vsllink_stableclocks_normal(int num_cycles, int tms)
+{
+       int tms_len;
+       uint16_t tms_append_byte;
+
+       if (vsllink_tms_data_len > 0)
+       {
+               // there are vsllink_tms_data_len more tms bits to be shifted
+               // so there are vsllink_tms_data_len + num_cycles tms bits in all
+               tms_len = vsllink_tms_data_len + num_cycles;
+               if (tms > 0)
+               {
+                       // append '1' for tms
+                       tms_append_byte = (uint16_t)((((1 << num_cycles) - 1) << vsllink_tms_data_len) & 0xFFFF);
+               }
+               else
+               {
+                       // append '0' for tms
+                       tms_append_byte = 0;
+               }
+               if (tms_len <= 16)
                {
-                       // there are vsllink_tms_data_len more tms bits to be shifted
-                       // so there are vsllink_tms_data_len + num_cycles tms bits in all
-                       tms_len = vsllink_tms_data_len + num_cycles;
-                       if (tms_len <= 16)
+                       // merge into last tms shift
+                       if (tms_len < 8)
+                       {
+                               // just add to vsllink_tms_data_len
+                               // same result if tun through
+                               //vsllink_tms_data_len += num_cycles;
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] |= (uint8_t)(tms_append_byte & 0xFF);
+                       }
+                       else if (tms_len == 8)
                        {
-                               // merge into last tms shift
-                               if (tms_len < 8)
+                               // end last tms shift command
+                               // just reduce it, and append last tms byte
+                               (*vsllink_tms_cmd_pos)--;
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (uint8_t)(tms_append_byte & 0xFF);
+                       }
+                       else if (tms_len < 16)
+                       {
+                               if ((*vsllink_tms_cmd_pos & VSLLINK_CMDJTAGSEQ_LENMSK) < VSLLINK_CMDJTAGSEQ_LENMSK)
                                {
-                                       // just add to vsllink_tms_data_len
-                                       // same result if tun through
-                                       //vsllink_tms_data_len += num_cycles;
+                                       // every tms shift command can contain VSLLINK_CMDJTAGSEQ_LENMSK + 1 bytes in most
+                                       // there is enought tms length in the current tms shift command
+                                       // increase the tms byte length by 1 and set the last byte to 0
+                                       (*vsllink_tms_cmd_pos)++;
+                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (uint8_t)(tms_append_byte & 0xFF);
+                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = (uint8_t)(tms_append_byte >> 8);
                                }
-                               else if (tms_len == 8)
+                               else
                                {
-                                       // end last tms shift command
-                                       // just reduce it, no need to append_tms
+                                       // every tms shift command can contain VSLLINK_CMDJTAGSEQ_LENMSK + 1 bytes in most
+                                       // not enough tms length in the current tms shift command
+                                       // so a new command should be added
+                                       // first decrease byte length of last tms shift command
                                        (*vsllink_tms_cmd_pos)--;
-                                       vsllink_usb_out_buffer_idx++;
-                               }
-                               else if (tms_len < 16)
-                               {
-                                       if ((*vsllink_tms_cmd_pos & VSLLINK_CMDJTAGSEQ_LENMSK) < VSLLINK_CMDJTAGSEQ_LENMSK)
-                                       {
-                                               // every tms shift command can contain VSLLINK_CMDJTAGSEQ_LENMSK + 1 bytes in most
-                                               // there is enought tms length in the current tms shift command
-                                               // increase the tms byte length by 1 and set the last byte to 0
-                                               (*vsllink_tms_cmd_pos)++;
-                                               vsllink_usb_out_buffer_idx++;
-                                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = 0;
-                                       }
-                                       else
-                                       {
-                                               // every tms shift command can contain VSLLINK_CMDJTAGSEQ_LENMSK + 1 bytes in most
-                                               // not enough tms length in the current tms shift command
-                                               // so a new command should be added
-                                               // first decrease byte length of last tms shift command
-                                               (*vsllink_tms_cmd_pos)--;
-                                               // move the command pointer to the next empty position
-                                               vsllink_usb_out_buffer_idx++;
-                                               // add new command(3 bytes)
-                                               vsllink_tap_ensure_space(0, 3);
-                                               vsllink_tms_cmd_pos = &vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx];
-                                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSBYTE | 1;
-                                               vsllink_usb_out_buffer[++vsllink_usb_out_buffer_idx] = 0;
-                                       }
-                               }
-                               else if (tms_len == 16)
-                               {
-                                       // end last tms shift command
-                                       vsllink_usb_out_buffer_idx++;
-                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = 0;
-                               }
-
-                               vsllink_tms_data_len = (vsllink_tms_data_len + num_cycles) & 7;
-                               if (vsllink_tms_data_len == 0)
-                               {
-                                       vsllink_tms_cmd_pos = NULL;
+                                       // append last tms byte and move the command pointer to the next empty position
+                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (uint8_t)(tms_append_byte & 0xFF);
+                                       // add new command(3 bytes)
+                                       vsllink_tap_ensure_space(0, 3);
+                                       vsllink_tms_cmd_pos = &vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx];
+                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSBYTE | 1;
+                                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = (uint8_t)(tms_append_byte >> 8);
                                }
-                               num_cycles = 0;
                        }
-                       else
+                       else if (tms_len == 16)
                        {
-                               vsllink_usb_out_buffer_idx++;
-                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = 0;
+                               // end last tms shift command
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (uint8_t)(tms_append_byte & 0xFF);
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (uint8_t)(tms_append_byte >> 8);
+                       }
 
-                               num_cycles -= 16 - vsllink_tms_data_len;
-                               vsllink_tms_data_len = 0;
+                       vsllink_tms_data_len = tms_len & 7;
+                       if (vsllink_tms_data_len == 0)
+                       {
                                vsllink_tms_cmd_pos = NULL;
                        }
+                       num_cycles = 0;
+               }
+               else
+               {
+                       // more shifts will be needed
+                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] |= (uint8_t)(tms_append_byte & 0xFF);
+                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (uint8_t)(tms_append_byte >> 8);
+
+                       num_cycles -= 16 - vsllink_tms_data_len;
+                       vsllink_tms_data_len = 0;
+                       vsllink_tms_cmd_pos = NULL;
                }
        }
        // from here vsllink_tms_data_len == 0 or num_cycles == 0
@@ -860,7 +1030,15 @@ void vsllink_runtest(int num_cycles)
                        vsllink_tap_ensure_space(1, 5);
                        // if tms_len > 0, vsllink_tms_data_len == 0
                        // so just add new command
-                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMS0BYTE;
+                       // LSB of the command byte is the tms value when do the shifting
+                       if (tms > 0)
+                       {
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSCLOCK | 1;
+                       }
+                       else
+                       {
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSCLOCK;
+                       }
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tms_len >> 0) & 0xff;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tms_len >> 8) & 0xff;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tms_len >> 16) & 0xff;
@@ -873,38 +1051,102 @@ void vsllink_runtest(int num_cycles)
                        if (tms_len > 0xFFFF)
                        {
                                vsllink_tap_execute();
-                               vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGSEQCMD;
-                               vsllink_usb_out_buffer_idx = 3;
                        }
                }
 
+               // post-process
                vsllink_tms_data_len = num_cycles & 7;
                if (vsllink_tms_data_len > 0)
                {
                        vsllink_tap_ensure_space(0, 3);
                        vsllink_tms_cmd_pos = &vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx];
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_TMSBYTE | 1;
-                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = 0;
+                       if (tms > 0)
+                       {
+                               // append '1' for tms
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = (1 << vsllink_tms_data_len) - 1;
+                       }
+                       else
+                       {
+                               // append '0' for tms
+                               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] = 0x00;
+                       }
+               }
+       }
+}
+static void vsllink_stableclocks_dma(int num_cycles, int tms)
+{
+       int i, cur_cycles;
+
+       if (tap_length & 7)
+       {
+               if ((8 - (tap_length & 7)) < num_cycles)
+               {
+                       cur_cycles = 8 - (tap_length & 7);
+               }
+               else
+               {
+                       cur_cycles = num_cycles;
+               }
+               for (i = 0; i < cur_cycles; i++)
+               {
+                       vsllink_tap_append_step(tms, 0);
+               }
+               num_cycles -= cur_cycles;
+       }
+
+       while (num_cycles > 0)
+       {
+               if (num_cycles > 8 * tap_buffer_size)
+               {
+                       cur_cycles = 8 * tap_buffer_size;
+               }
+               else
+               {
+                       cur_cycles = num_cycles;
+               }
+
+               vsllink_tap_ensure_space(0, cur_cycles);
+
+               for (i = 0; i < cur_cycles; i++)
+               {
+                       vsllink_tap_append_step(tms, 0);
                }
+
+               num_cycles -= cur_cycles;
+       }
+}
+
+static void vsllink_runtest(int num_cycles)
+{
+       tap_state_t saved_end_state = tap_get_end_state();
+
+       if (tap_get_state() != TAP_IDLE)
+       {
+               // enter into IDLE state
+               vsllink_end_state(TAP_IDLE);
+               vsllink_state_move();
        }
 
+       vsllink_stableclocks(num_cycles, 0);
+
        // post-process
        // set end_state
        vsllink_end_state(saved_end_state);
-       cur_state = TAP_IDLE;
-       if (end_state != TAP_IDLE)
+       tap_set_state(TAP_IDLE);
+       if (tap_get_end_state() != TAP_IDLE)
        {
                vsllink_state_move();
        }
 }
 
-void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command)
+static void vsllink_scan_normal(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command)
 {
-       enum tap_state saved_end_state;
-       u8 bits_left, tms_tmp, tdi_len;
+       tap_state_t saved_end_state;
+       uint8_t bits_left, tms_tmp, tdi_len;
        int i;
 
-       if (0 == scan_size )
+       if (0 == scan_size)
        {
                return;
        }
@@ -915,24 +1157,24 @@ void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, s
                LOG_ERROR("Your implementation of VSLLink has not enough buffer");
                exit(-1);
        }
-       
-       saved_end_state = end_state;
-       
+
+       saved_end_state = tap_get_end_state();
+
        /* Move to appropriate scan state */
        vsllink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 
        if (vsllink_tms_data_len > 0)
        {
-               if (cur_state == end_state)
+               if (tap_get_state() == tap_get_end_state())
                {
                        // already in IRSHIFT or DRSHIFT state
                        // merge tms data in the last tms shift command into next scan command
-                       if(*vsllink_tms_cmd_pos < 1)
+                       if (*vsllink_tms_cmd_pos < 1)
                        {
                                LOG_ERROR("There MUST be some bugs in the driver");
                                exit(-1);
                        }
-                       else if(*vsllink_tms_cmd_pos < 2)
+                       else if (*vsllink_tms_cmd_pos < 2)
                        {
                                tms_tmp = vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx];
                                vsllink_usb_out_buffer_idx--;
@@ -944,11 +1186,11 @@ void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, s
                        }
 
                        vsllink_tap_ensure_space(1, tdi_len + 7);
-                       // VSLLINK_CMDJTAGSEQ_SCAN ored by 1 means that tms_before is valid 
+                       // VSLLINK_CMDJTAGSEQ_SCAN ored by 1 means that tms_before is valid
                        // which is merged from the last tms shift command
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_SCAN | 1;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = ((tdi_len + 1) >> 0) & 0xff;
-                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = ((tdi_len + 1)>> 8) & 0xff;
+                       vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = ((tdi_len + 1) >> 8) & 0xff;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = tms_tmp;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = buffer[0] << (8 - vsllink_tms_data_len);
 
@@ -961,20 +1203,20 @@ void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, s
                                }
                        }
 
-                       vsllink_tap_append_scan(scan_size - vsllink_tms_data_len, buffer, command, vsllink_tms_data_len);
+                       vsllink_tap_append_scan_normal(scan_size - vsllink_tms_data_len, buffer, command, vsllink_tms_data_len);
                        scan_size -= 8 - vsllink_tms_data_len;
                        vsllink_tms_data_len = 0;
                }
                else
                {
-                       vsllink_append_tms();
+                       vsllink_state_move();
                        vsllink_tap_ensure_space(1, tdi_len + 5);
 
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_SCAN;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tdi_len >> 0) & 0xff;
                        vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = (tdi_len >> 8) & 0xff;
 
-                       vsllink_tap_append_scan(scan_size, buffer, command, 0);
+                       vsllink_tap_append_scan_normal(scan_size, buffer, command, 0);
                }
        }
        else
@@ -984,15 +1226,15 @@ void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, s
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_CMDJTAGSEQ_SCAN | 1;
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = ((tdi_len + 1) >> 0) & 0xff;
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = ((tdi_len + 1)>> 8) & 0xff;
-               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(cur_state, end_state);
+               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(tap_get_state(), tap_get_end_state());
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = 0;
 
-               vsllink_tap_append_scan(scan_size, buffer, command, 8);
+               vsllink_tap_append_scan_normal(scan_size, buffer, command, 8);
        }
        vsllink_end_state(saved_end_state);
 
        bits_left = scan_size & 0x07;
-       cur_state = ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE;
+       tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 
        if (bits_left > 0)
        {
@@ -1003,24 +1245,51 @@ void vsllink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, s
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = 1 << 7;
        }
 
-       if (cur_state != end_state)
+       if (tap_get_state() != tap_get_end_state())
        {
-               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(cur_state, end_state);
+               vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = VSLLINK_TAP_MOVE(tap_get_state(), tap_get_end_state());
        }
        else
        {
                vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx++] = 0;
        }
 
-       cur_state = end_state;
+       tap_set_state(tap_get_end_state());
+}
+static void vsllink_scan_dma(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command)
+{
+       tap_state_t saved_end_state;
+
+       saved_end_state = tap_get_end_state();
+
+       /* Move to appropriate scan state */
+       vsllink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
+
+       vsllink_state_move();
+       vsllink_end_state(saved_end_state);
+
+       /* Scan */
+       vsllink_tap_append_scan_dma(scan_size, buffer, command);
+
+       tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
+       while (tap_length % 8 != 0)
+       {
+               // more 0s in Pause
+               vsllink_tap_append_step(0, 0);
+       }
+
+       if (tap_get_state() != tap_get_end_state())
+       {
+               vsllink_state_move();
+       }
 }
 
-void vsllink_reset(int trst, int srst)
+static void vsllink_reset(int trst, int srst)
 {
        int result;
 
        LOG_DEBUG("trst: %i, srst: %i", trst, srst);
-       
+
        /* Signals are active low */
        vsllink_usb_out_buffer[0] = VSLLINK_CMD_SET_PORT;
        vsllink_usb_out_buffer[1] = JTAG_PINMSK_SRST | JTAG_PINMSK_TRST;
@@ -1041,93 +1310,183 @@ void vsllink_reset(int trst, int srst)
        }
 }
 
-void vsllink_simple_command(u8 command)
+static void vsllink_simple_command(uint8_t command)
 {
        int result;
-       
+
        DEBUG_JTAG_IO("0x%02x", command);
-       
+
        vsllink_usb_out_buffer[0] = command;
        result = vsllink_usb_write(vsllink_jtag_handle, 1);
-       
+
        if (result != 1)
        {
                LOG_ERROR("VSLLink command 0x%02x failed (%d)", command, result);
        }
 }
 
-int vsllink_handle_usb_vid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(vsllink_handle_mode_command)
 {
        if (argc != 1) {
-           LOG_ERROR("parameter error, should be one parameter for VID");
-               return ERROR_OK;
+               LOG_ERROR("parameter error, should be one parameter for VID");
+               return ERROR_FAIL;
        }
 
-       vsllink_vid = strtol(args[0], NULL, 0);
+       if (!strcmp(args[0], "normal"))
+       {
+               vsllink_mode = VSLLINK_MODE_NORMAL;
+       }
+       else if (!strcmp(args[0], "dma"))
+       {
+               vsllink_mode = VSLLINK_MODE_DMA;
+       }
+       else
+       {
+               LOG_ERROR("invalid vsllink_mode: %s", args[0]);
+               return ERROR_FAIL;
+       }
 
        return ERROR_OK;
 }
 
-int vsllink_handle_usb_pid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(vsllink_handle_usb_vid_command)
 {
-       if (argc != 1) {
-           LOG_ERROR("parameter error, should be one parameter for PID");
+       if (argc != 1)
+       {
+               LOG_ERROR("parameter error, should be one parameter for VID");
                return ERROR_OK;
        }
 
-       vsllink_pid = strtol(args[0], NULL, 0);
+       COMMAND_PARSE_NUMBER(u16, args[0], vsllink_usb_vid);
+       return ERROR_OK;
+}
 
+COMMAND_HANDLER(vsllink_handle_usb_pid_command)
+{
+       if (argc != 1)
+       {
+               LOG_ERROR("parameter error, should be one parameter for PID");
+               return ERROR_OK;
+       }
+       COMMAND_PARSE_NUMBER(u16, args[0], vsllink_usb_pid);
        return ERROR_OK;
 }
 
-int vsllink_handle_usb_bulkin_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(vsllink_handle_usb_bulkin_command)
 {
-       if (argc != 1) {
-           LOG_ERROR("parameter error, should be one parameter for BULKIN endpoint");
+       if (argc != 1)
+       {
+               LOG_ERROR("parameter error, should be one parameter for BULKIN endpoint");
                return ERROR_OK;
        }
 
-       vsllink_bulkin = strtol(args[0], NULL, 0) | 0x80;
+       COMMAND_PARSE_NUMBER(u8, args[0], vsllink_usb_bulkin);
+
+       vsllink_usb_bulkin |= 0x80;
 
        return ERROR_OK;
 }
 
-int vsllink_handle_usb_bulkout_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(vsllink_handle_usb_bulkout_command)
 {
-       if (argc != 1) {
-           LOG_ERROR("parameter error, should be one parameter for BULKOUT endpoint");
+       if (argc != 1)
+       {
+               LOG_ERROR("parameter error, should be one parameter for BULKOUT endpoint");
                return ERROR_OK;
        }
 
-       vsllink_bulkout = strtol(args[0], NULL, 0);
+       COMMAND_PARSE_NUMBER(u8, args[0], vsllink_usb_bulkout);
+
+       vsllink_usb_bulkout &= ~0x80;
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(vsllink_handle_usb_interface_command)
+{
+       if (argc != 1)
+       {
+               LOG_ERROR("parameter error, should be one parameter for interface number");
+               return ERROR_OK;
+       }
 
+       COMMAND_PARSE_NUMBER(u8, args[0], vsllink_usb_interface);
        return ERROR_OK;
 }
 
 /***************************************************************************/
 /* VSLLink tap functions */
 
-void vsllink_tap_init(void)
+static void vsllink_tap_init_normal(void)
 {
        vsllink_usb_out_buffer_idx = 0;
        vsllink_usb_in_want_length = 0;
        pending_scan_results_length = 0;
 }
+static void vsllink_tap_init_dma(void)
+{
+       tap_length = 0;
+       pending_scan_results_length = 0;
+}
 
-void vsllink_tap_ensure_space(int scans, int bytes)
+static void vsllink_tap_ensure_space_normal(int scans, int length)
 {
        int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
        int available_bytes = VSLLINK_BufferSize - vsllink_usb_out_buffer_idx;
-       
-       if (scans > available_scans || bytes > available_bytes)
+
+       if (scans > available_scans || length > available_bytes)
        {
                vsllink_tap_execute();
-               vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGSEQCMD;
-               vsllink_usb_out_buffer_idx = 3;
+       }
+}
+static void vsllink_tap_ensure_space_dma(int scans, int length)
+{
+       int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
+       int available_bytes = tap_buffer_size * 8 - tap_length;
+
+       if (scans > available_scans || length > available_bytes)
+       {
+               vsllink_tap_execute();
+       }
+}
+
+static void vsllink_tap_append_step(int tms, int tdi)
+{
+       last_tms = tms;
+       int index = tap_length / 8;
+
+       if (index < tap_buffer_size)
+       {
+               int bit_index = tap_length % 8;
+               uint8_t bit = 1 << bit_index;
+
+               if (tms)
+               {
+                       tms_buffer[index] |= bit;
+               }
+               else
+               {
+                       tms_buffer[index] &= ~bit;
+               }
+
+               if (tdi)
+               {
+                       tdi_buffer[index] |= bit;
+               }
+               else
+               {
+                       tdi_buffer[index] &= ~bit;
+               }
+
+               tap_length++;
+       }
+       else
+       {
+               LOG_ERROR("buffer overflow, tap_length=%d", tap_length);
        }
 }
 
-void vsllink_tap_append_scan(int length, u8 *buffer, scan_command_t *command, int offset)
+static void vsllink_tap_append_scan_normal(int length, uint8_t *buffer, scan_command_t *command, int offset)
 {
        pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
        int i;
@@ -1152,10 +1511,44 @@ void vsllink_tap_append_scan(int length, u8 *buffer, scan_command_t *command, in
 
        pending_scan_results_length++;
 }
+static void vsllink_tap_append_scan_dma(int length, uint8_t *buffer, scan_command_t *command)
+{
+       pending_scan_result_t *pending_scan_result;
+       int len_tmp, len_all, i;
+
+       len_all = 0;
+       while (len_all < length)
+       {
+               if ((length - len_all) > tap_buffer_size * 8)
+               {
+                       len_tmp = tap_buffer_size * 8;
+               }
+               else
+               {
+                       len_tmp = length - len_all;
+               }
+
+               vsllink_tap_ensure_space(1, (len_tmp + 7) & ~7);
+
+               pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
+               pending_scan_result->offset = tap_length;
+               pending_scan_result->length = len_tmp;
+               pending_scan_result->command = command;
+               pending_scan_result->buffer = buffer + len_all / 8;
+
+               for (i = 0; i < len_tmp; i++)
+               {
+                       vsllink_tap_append_step(((len_all + i) < length-1 ? 0 : 1), (buffer[(len_all + i)/8] >> ((len_all + i)%8)) & 1);
+               }
+
+               pending_scan_results_length++;
+               len_all += len_tmp;
+       }
+}
 
 /* Pad and send a tap sequence to the device, and receive the answer.
  * For the purpose of padding we assume that we are in reset or idle or pause state. */
-int vsllink_tap_execute(void)
+static int vsllink_tap_execute_normal(void)
 {
        int i;
        int result;
@@ -1163,9 +1556,9 @@ int vsllink_tap_execute(void)
 
        if (vsllink_tms_data_len > 0)
        {
-               if((cur_state != TAP_RESET) && (cur_state != TAP_IDLE) && (cur_state != TAP_IRPAUSE) && (cur_state != TAP_DRPAUSE))
+               if ((tap_get_state() != TAP_RESET) && (tap_get_state() != TAP_IDLE) && (tap_get_state() != TAP_IRPAUSE) && (tap_get_state() != TAP_DRPAUSE))
                {
-                       LOG_WARNING("%s is not in RESET or IDLE or PAUSR state", jtag_state_name(cur_state));
+                       LOG_WARNING("%s is not in RESET or IDLE or PAUSR state", tap_state_name(tap_get_state()));
                }
 
                if (vsllink_usb_out_buffer[vsllink_usb_out_buffer_idx] & (1 << (vsllink_tms_data_len - 1)))
@@ -1183,7 +1576,7 @@ int vsllink_tap_execute(void)
                        vsllink_tms_data_len = 0;
                }
        }
-       
+
        if (vsllink_usb_out_buffer_idx > 3)
        {
                if (vsllink_usb_out_buffer[0] == VSLLINK_CMD_HW_JTAGSEQCMD)
@@ -1193,13 +1586,13 @@ int vsllink_tap_execute(void)
                }
 
                result = vsllink_usb_message(vsllink_jtag_handle, vsllink_usb_out_buffer_idx, vsllink_usb_in_want_length);
-       
+
                if (result == vsllink_usb_in_want_length)
                {
                        for (i = 0; i < pending_scan_results_length; i++)
                        {
                                pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
-                               u8 *buffer = pending_scan_result->buffer;
+                               uint8_t *buffer = pending_scan_result->buffer;
                                int length = pending_scan_result->length;
                                int offset = pending_scan_result->offset;
                                scan_command_t *command = pending_scan_result->command;
@@ -1209,7 +1602,7 @@ int vsllink_tap_execute(void)
                                        // IRSHIFT or DRSHIFT
                                        buf_set_buf(vsllink_usb_in_buffer, first * 8 + offset, buffer, 0, length);
                                        first += (length + offset + 7) >> 3;
-       
+
                                        DEBUG_JTAG_IO("JTAG scan read(%d bits):", length);
 #ifdef _DEBUG_JTAG_IO_
                                        vsllink_debug_buffer(buffer, (length + 7) >> 3);
@@ -1235,80 +1628,177 @@ int vsllink_tap_execute(void)
                        LOG_ERROR("vsllink_tap_execute, wrong result %d, expected %d", result, vsllink_usb_in_want_length);
                        return ERROR_JTAG_QUEUE_FAILED;
                }
-               
+
+               vsllink_tap_init();
+       }
+       reset_command_pointer();
+
+       return ERROR_OK;
+}
+static int vsllink_tap_execute_dma(void)
+{
+       int byte_length;
+       int i;
+       int result;
+
+       if (tap_length > 0)
+       {
+               /* Pad last byte so that tap_length is divisible by 8 */
+               while (tap_length % 8 != 0)
+               {
+                       /* More of the last TMS value keeps us in the same state,
+                        * analogous to free-running JTAG interfaces. */
+                       vsllink_tap_append_step(last_tms, 0);
+               }
+               byte_length = tap_length / 8;
+
+               vsllink_usb_out_buffer[0] = VSLLINK_CMD_HW_JTAGRAWCMD;
+               vsllink_usb_out_buffer[1] = ((byte_length * 2 + 3) >> 0) & 0xff;                // package size
+               vsllink_usb_out_buffer[2] = ((byte_length * 2 + 3) >> 8) & 0xff;
+
+               memcpy(&vsllink_usb_out_buffer[3], tdi_buffer, byte_length);
+               memcpy(&vsllink_usb_out_buffer[3 + byte_length], tms_buffer, byte_length);
+
+               result = vsllink_usb_message(vsllink_jtag_handle, 3 + 2 * byte_length, byte_length);
+               if (result == byte_length)
+               {
+                       for (i = 0; i < pending_scan_results_length; i++)
+                       {
+                               pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
+                               uint8_t *buffer = pending_scan_result->buffer;
+                               int length = pending_scan_result->length;
+                               int first = pending_scan_result->offset;
+
+                               scan_command_t *command = pending_scan_result->command;
+                               buf_set_buf(vsllink_usb_in_buffer, first, buffer, 0, length);
+
+                               DEBUG_JTAG_IO("JTAG scan read(%d bits, from %d bits):", length, first);
+#ifdef _DEBUG_JTAG_IO_
+                               vsllink_debug_buffer(buffer, (length + 7) >> 3);
+#endif
+
+                               if (jtag_read_buffer(buffer, command) != ERROR_OK)
+                               {
+                                       vsllink_tap_init();
+                                       return ERROR_JTAG_QUEUE_FAILED;
+                               }
+
+                               if (pending_scan_result->buffer != NULL)
+                               {
+                                       free(pending_scan_result->buffer);
+                               }
+                       }
+               }
+               else
+               {
+                       LOG_ERROR("vsllink_tap_execute, wrong result %d, expected %d", result, byte_length);
+                       return ERROR_JTAG_QUEUE_FAILED;
+               }
+
                vsllink_tap_init();
        }
-       
+
        return ERROR_OK;
 }
 
 /*****************************************************************************/
 /* VSLLink USB low-level functions */
 
-vsllink_jtag_t* vsllink_usb_open(void)
+static vsllink_jtag_t* vsllink_usb_open(void)
 {
        struct usb_bus *busses;
        struct usb_bus *bus;
        struct usb_device *dev;
-       
+       int ret;
+
        vsllink_jtag_t *result;
-       
+
        result = (vsllink_jtag_t*) malloc(sizeof(vsllink_jtag_t));
-       
+
        usb_init();
        usb_find_busses();
        usb_find_devices();
-       
+
        busses = usb_get_busses();
-       
+
        /* find vsllink_jtag device in usb bus */
-       
+
        for (bus = busses; bus; bus = bus->next)
        {
                for (dev = bus->devices; dev; dev = dev->next)
                {
-                       if ((dev->descriptor.idVendor == vsllink_vid) && (dev->descriptor.idProduct == vsllink_pid))
+                       if ((dev->descriptor.idVendor == vsllink_usb_vid) && (dev->descriptor.idProduct == vsllink_usb_pid))
                        {
                                result->usb_handle = usb_open(dev);
-                               
+                               if (NULL == result->usb_handle)
+                               {
+                                       LOG_ERROR("failed to open %04X:%04X, not enough permissions?", vsllink_usb_vid, vsllink_usb_pid);
+                                       exit(-1);
+                               }
+
                                /* usb_set_configuration required under win32 */
-                               usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
-                               usb_claim_interface(result->usb_handle, 0);
-                               
+                               ret = usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
+                               if (ret != 0)
+                               {
+                                       LOG_ERROR("fail to set configuration to %d, %d returned, not enough permissions?", dev->config[0].bConfigurationValue, ret);
+                                       exit(-1);
+                               }
+                               ret = usb_claim_interface(result->usb_handle, vsllink_usb_interface);
+                               if (ret != 0)
+                               {
+                                       LOG_ERROR("fail to claim interface %d, %d returned", vsllink_usb_interface, ret);
+                                       exit(-1);
+                               }
+
 #if 0
-                               /* 
+                               /*
                                 * This makes problems under Mac OS X. And is not needed
                                 * under Windows. Hopefully this will not break a linux build
                                 */
                                usb_set_altinterface(result->usb_handle, 0);
-#endif                         
+#endif
                                return result;
                        }
                }
        }
-       
+
        free(result);
        return NULL;
 }
 
-void vsllink_usb_close(vsllink_jtag_t *vsllink_jtag)
+static void vsllink_usb_close(vsllink_jtag_t *vsllink_jtag)
 {
-       usb_close(vsllink_jtag->usb_handle);
+       int ret;
+
+       ret = usb_release_interface(vsllink_jtag->usb_handle, vsllink_usb_interface);
+       if (ret != 0)
+       {
+               LOG_ERROR("fail to release interface %d, %d returned", vsllink_usb_interface, ret);
+               exit(-1);
+       }
+
+       ret = usb_close(vsllink_jtag->usb_handle);
+       if (ret != 0)
+       {
+               LOG_ERROR("fail to close usb, %d returned", ret);
+               exit(-1);
+       }
+
        free(vsllink_jtag);
 }
 
 /* Send a message and receive the reply. */
-int vsllink_usb_message(vsllink_jtag_t *vsllink_jtag, int out_length, int in_length)
+static int vsllink_usb_message(vsllink_jtag_t *vsllink_jtag, int out_length, int in_length)
 {
        int result;
-       
+
        result = vsllink_usb_write(vsllink_jtag, out_length);
        if (result == out_length)
        {
                if (in_length > 0)
                {
                        result = vsllink_usb_read(vsllink_jtag);
-                       if (result == in_length )
+                       if (result == in_length)
                        {
                                return result;
                        }
@@ -1328,21 +1818,21 @@ int vsllink_usb_message(vsllink_jtag_t *vsllink_jtag, int out_length, int in_len
 }
 
 /* Write data from out_buffer to USB. */
-int vsllink_usb_write(vsllink_jtag_t *vsllink_jtag, int out_length)
+static int vsllink_usb_write(vsllink_jtag_t *vsllink_jtag, int out_length)
 {
        int result;
-       
+
        if (out_length > VSLLINK_BufferSize)
        {
                LOG_ERROR("vsllink_jtag_write illegal out_length=%d (max=%d)", out_length, VSLLINK_BufferSize);
                return -1;
        }
-       
-       result = usb_bulk_write(vsllink_jtag->usb_handle, vsllink_bulkout, \
+
+       result = usb_bulk_write(vsllink_jtag->usb_handle, vsllink_usb_bulkout, \
                (char *)vsllink_usb_out_buffer, out_length, VSLLINK_USB_TIMEOUT);
-       
+
        DEBUG_JTAG_IO("vsllink_usb_write, out_length = %d, result = %d", out_length, result);
-       
+
 #ifdef _DEBUG_USB_COMMS_
        LOG_DEBUG("USB out:");
        vsllink_debug_buffer(vsllink_usb_out_buffer, out_length);
@@ -1356,13 +1846,13 @@ int vsllink_usb_write(vsllink_jtag_t *vsllink_jtag, int out_length)
 }
 
 /* Read data from USB into in_buffer. */
-int vsllink_usb_read(vsllink_jtag_t *vsllink_jtag)
+static int vsllink_usb_read(vsllink_jtag_t *vsllink_jtag)
 {
-       int result = usb_bulk_read(vsllink_jtag->usb_handle, vsllink_bulkin, \
+       int result = usb_bulk_read(vsllink_jtag->usb_handle, vsllink_usb_bulkin, \
                (char *)vsllink_usb_in_buffer, VSLLINK_BufferSize, VSLLINK_USB_TIMEOUT);
 
        DEBUG_JTAG_IO("vsllink_usb_read, result = %d", result);
-       
+
 #ifdef _DEBUG_USB_COMMS_
        LOG_DEBUG("USB in:");
        vsllink_debug_buffer(vsllink_usb_in_buffer, result);
@@ -1372,13 +1862,14 @@ int vsllink_usb_read(vsllink_jtag_t *vsllink_jtag)
 
 #define BYTES_PER_LINE  16
 
-void vsllink_debug_buffer(u8 *buffer, int length)
+#if defined _DEBUG_USB_COMMS_ || defined _DEBUG_JTAG_IO_
+static void vsllink_debug_buffer(uint8_t *buffer, int length)
 {
        char line[81];
        char s[4];
        int i;
        int j;
-       
+
        for (i = 0; i < length; i += BYTES_PER_LINE)
        {
                snprintf(line, 5, "%04x", i);
@@ -1387,6 +1878,42 @@ void vsllink_debug_buffer(u8 *buffer, int length)
                        snprintf(s, 4, " %02x", buffer[j]);
                        strcat(line, s);
                }
-               LOG_DEBUG(line);
+               LOG_DEBUG("%s", line);
        }
 }
+#endif // _DEBUG_USB_COMMS_ || _DEBUG_JTAG_IO_
+
+static int vsllink_register_commands(struct command_context_s *cmd_ctx)
+{
+       register_command(cmd_ctx, NULL, "vsllink_usb_vid",
+                       vsllink_handle_usb_vid_command, COMMAND_CONFIG,
+                       NULL);
+       register_command(cmd_ctx, NULL, "vsllink_usb_pid",
+                       vsllink_handle_usb_pid_command, COMMAND_CONFIG,
+                       NULL);
+       register_command(cmd_ctx, NULL, "vsllink_usb_bulkin",
+                       vsllink_handle_usb_bulkin_command, COMMAND_CONFIG,
+                       NULL);
+       register_command(cmd_ctx, NULL, "vsllink_usb_bulkout",
+                       vsllink_handle_usb_bulkout_command, COMMAND_CONFIG,
+                       NULL);
+       register_command(cmd_ctx, NULL, "vsllink_usb_interface",
+                       vsllink_handle_usb_interface_command, COMMAND_CONFIG,
+                       NULL);
+       register_command(cmd_ctx, NULL, "vsllink_mode",
+                       vsllink_handle_mode_command, COMMAND_CONFIG,
+                       NULL);
+
+       return ERROR_OK;
+}
+
+jtag_interface_t vsllink_interface = {
+               .name = "vsllink",
+               .register_commands = &vsllink_register_commands,
+               .init = &vsllink_init,
+               .quit = &vsllink_quit,
+               .khz = &vsllink_khz,
+               .speed = &vsllink_speed,
+               .speed_div = &vsllink_speed_div,
+               .execute_queue = &vsllink_execute_queue,
+       };