--- /dev/null
+/**************************************************************************
+*   Copyright (C) 2012 by Andreas Fritiofson                              *
+*   andreas.fritiofson@gmail.com                                          *
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+*   This program is distributed in the hope that it will be useful,       *
+*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+*   GNU General Public License for more details.                          *
+*                                                                         *
+*   You should have received a copy of the GNU General Public License     *
+*   along with this program; if not, write to the                         *
+*   Free Software Foundation, Inc.,                                       *
+*   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+***************************************************************************/
+
+/**
+ * @file
+ * JTAG adapters based on the FT2232 full and high speed USB parts are
+ * popular low cost JTAG debug solutions.  Many FT2232 based JTAG adapters
+ * are discrete, but development boards may integrate them as alternatives
+ * to more capable (and expensive) third party JTAG pods.
+ *
+ * JTAG uses only one of the two communications channels ("MPSSE engines")
+ * on these devices.  Adapters based on FT4232 parts have four ports/channels
+ * (A/B/C/D), instead of just two (A/B).
+ *
+ * Especially on development boards integrating one of these chips (as
+ * opposed to discrete pods/dongles), the additional channels can be used
+ * for a variety of purposes, but OpenOCD only uses one channel at a time.
+ *
+ *  - As a USB-to-serial adapter for the target's console UART ...
+ *    which may be able to support ROM boot loaders that load initial
+ *    firmware images to flash (or SRAM).
+ *
+ *  - On systems which support ARM's SWD in addition to JTAG, or instead
+ *    of it, that second port can be used for reading SWV/SWO trace data.
+ *
+ *  - Additional JTAG links, e.g. to a CPLD or * FPGA.
+ *
+ * FT2232 based JTAG adapters are "dumb" not "smart", because most JTAG
+ * request/response interactions involve round trips over the USB link.
+ * A "smart" JTAG adapter has intelligence close to the scan chain, so it
+ * can for example poll quickly for a status change (usually taking on the
+ * order of microseconds not milliseconds) before beginning a queued
+ * transaction which require the previous one to have completed.
+ *
+ * There are dozens of adapters of this type, differing in details which
+ * this driver needs to understand.  Those "layout" details are required
+ * as part of FT2232 driver configuration.
+ *
+ * This code uses information contained in the MPSSE specification which was
+ * found here:
+ * http://www.ftdichip.com/Documents/AppNotes/AN2232C-01_MPSSE_Cmnd.pdf
+ * Hereafter this is called the "MPSSE Spec".
+ *
+ * The datasheet for the ftdichip.com's FT2232D part is here:
+ * http://www.ftdichip.com/Documents/DataSheets/DS_FT2232D.pdf
+ *
+ * Also note the issue with code 0x4b (clock data to TMS) noted in
+ * http://developer.intra2net.com/mailarchive/html/libftdi/2009/msg00292.html
+ * which can affect longer JTAG state paths.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* project specific includes */
+#include <jtag/interface.h>
+#include <transport/transport.h>
+#include <helper/time_support.h>
+
+#if IS_CYGWIN == 1
+#include <windows.h>
+#endif
+
+#include <assert.h>
+
+/* FTDI access library includes */
+#include "mpsse.h"
+
+#define JTAG_MODE (LSB_FIRST | POS_EDGE_IN | NEG_EDGE_OUT)
+
+static char *ftdi_device_desc;
+static char *ftdi_serial;
+static uint8_t ftdi_channel;
+
+#define MAX_USB_IDS 8
+/* vid = pid = 0 marks the end of the list */
+static uint16_t ftdi_vid[MAX_USB_IDS + 1] = { 0 };
+static uint16_t ftdi_pid[MAX_USB_IDS + 1] = { 0 };
+
+static struct mpsse_ctx *mpsse_ctx;
+
+struct signal {
+       const char *name;
+       uint16_t data_mask;
+       uint16_t oe_mask;
+       bool invert_data;
+       bool invert_oe;
+       struct signal *next;
+};
+
+static struct signal *signals;
+
+static uint16_t output;
+static uint16_t direction;
+
+static struct signal *find_signal_by_name(const char *name)
+{
+       for (struct signal *sig = signals; sig; sig = sig->next) {
+               if (strcmp(name, sig->name) == 0)
+                       return sig;
+       }
+       return NULL;
+}
+
+static struct signal *create_signal(const char *name)
+{
+       struct signal **psig = &signals;
+       while (*psig)
+               psig = &(*psig)->next;
+
+       *psig = calloc(1, sizeof(**psig));
+       if (*psig)
+               (*psig)->name = strdup(name);
+       if ((*psig)->name == NULL) {
+               free(*psig);
+               *psig = NULL;
+       }
+       return *psig;
+}
+
+static int ftdi_set_signal(const struct signal *s, char value)
+{
+       int retval;
+       bool data;
+       bool oe;
+
+       if (s->data_mask == 0 && s->oe_mask == 0) {
+               LOG_ERROR("interface doesn't provide signal '%s'", s->name);
+               return ERROR_FAIL;
+       }
+       switch (value) {
+       case '0':
+               data = s->invert_data;
+               oe = !s->invert_oe;
+               break;
+       case '1':
+               if (s->data_mask == 0) {
+                       LOG_ERROR("interface can't drive '%s' high", s->name);
+                       return ERROR_FAIL;
+               }
+               data = !s->invert_data;
+               oe = !s->invert_oe;
+               break;
+       case 'z':
+       case 'Z':
+               if (s->oe_mask == 0) {
+                       LOG_ERROR("interface can't tri-state '%s'", s->name);
+                       return ERROR_FAIL;
+               }
+               data = s->invert_data;
+               oe = s->invert_oe;
+               break;
+       default:
+               assert(0 && "invalid signal level specifier");
+               return ERROR_FAIL;
+       }
+
+       output = data ? output | s->data_mask : output & ~s->data_mask;
+       if (s->oe_mask == s->data_mask)
+               direction = oe ? output | s->oe_mask : output & ~s->oe_mask;
+       else
+               output = oe ? output | s->oe_mask : output & ~s->oe_mask;
+
+       retval = mpsse_set_data_bits_low_byte(mpsse_ctx, output & 0xff, direction & 0xff);
+       if (retval == ERROR_OK)
+               retval = mpsse_set_data_bits_high_byte(mpsse_ctx, output >> 8, direction >> 8);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("couldn't initialize FTDI GPIO");
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
+       return ERROR_OK;
+}
+
+
+/**
+ * Function move_to_state
+ * moves the TAP controller from the current state to a
+ * \a goal_state through a path given by tap_get_tms_path().  State transition
+ * logging is performed by delegation to clock_tms().
+ *
+ * @param goal_state is the destination state for the move.
+ */
+static int move_to_state(tap_state_t goal_state)
+{
+       tap_state_t start_state = tap_get_state();
+
+       /*      goal_state is 1/2 of a tuple/pair of states which allow convenient
+               lookup of the required TMS pattern to move to this state from the
+               start state.
+       */
+
+       /* do the 2 lookups */
+       int tms_bits  = tap_get_tms_path(start_state, goal_state);
+       int tms_count = tap_get_tms_path_len(start_state, goal_state);
+
+       DEBUG_JTAG_IO("start=%s goal=%s", tap_state_name(start_state), tap_state_name(goal_state));
+
+       /* Track state transitions step by step */
+       for (int i = 0; i < tms_count; i++)
+               tap_set_state(tap_state_transition(tap_get_state(), (tms_bits >> i) & 1));
+
+       return mpsse_clock_tms_cs_out(mpsse_ctx,
+               (uint8_t *)&tms_bits,
+               0,
+               tms_count,
+               false,
+               JTAG_MODE);
+}
+
+static int ftdi_speed(int speed)
+{
+       int retval;
+       retval = mpsse_set_frequency(mpsse_ctx, speed);
+
+       if (retval < 0) {
+               LOG_ERROR("couldn't set FTDI TCK speed");
+               return retval;
+       }
+
+       return ERROR_OK;
+}
+
+static int ftdi_speed_div(int speed, int *khz)
+{
+       *khz = speed / 1000;
+       return ERROR_OK;
+}
+
+static int ftdi_khz(int khz, int *jtag_speed)
+{
+       *jtag_speed = khz * 1000;
+       return ERROR_OK;
+}
+
+static void ftdi_end_state(tap_state_t state)
+{
+       if (tap_is_state_stable(state))
+               tap_set_end_state(state);
+       else {
+               LOG_ERROR("BUG: %s is not a stable end state", tap_state_name(state));
+               exit(-1);
+       }
+}
+
+static int ftdi_execute_runtest(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+       int i;
+       uint8_t zero = 0;
+
+       DEBUG_JTAG_IO("runtest %i cycles, end in %s",
+               cmd->cmd.runtest->num_cycles,
+               tap_state_name(cmd->cmd.runtest->end_state));
+
+       if (tap_get_state() != TAP_IDLE)
+               move_to_state(TAP_IDLE);
+
+       /* TODO: Reuse ftdi_execute_stableclocks */
+       i = cmd->cmd.runtest->num_cycles;
+       while (i > 0 && retval == ERROR_OK) {
+               /* there are no state transitions in this code, so omit state tracking */
+               unsigned this_len = i > 7 ? 7 : i;
+               retval = mpsse_clock_tms_cs_out(mpsse_ctx, &zero, 0, this_len, false, JTAG_MODE);
+               i -= this_len;
+       }
+
+       ftdi_end_state(cmd->cmd.runtest->end_state);
+
+       if (tap_get_state() != tap_get_end_state())
+               move_to_state(tap_get_end_state());
+
+       DEBUG_JTAG_IO("runtest: %i, end in %s",
+               cmd->cmd.runtest->num_cycles,
+               tap_state_name(tap_get_end_state()));
+       return retval;
+}
+
+static int ftdi_execute_statemove(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+
+       DEBUG_JTAG_IO("statemove end in %s",
+               tap_state_name(cmd->cmd.statemove->end_state));
+
+       ftdi_end_state(cmd->cmd.statemove->end_state);
+
+       /* shortest-path move to desired end state */
+       if (tap_get_state() != tap_get_end_state() || tap_get_end_state() == TAP_RESET)
+               move_to_state(tap_get_end_state());
+
+       return retval;
+}
+
+/**
+ * Clock a bunch of TMS (or SWDIO) transitions, to change the JTAG
+ * (or SWD) state machine. REVISIT: Not the best method, perhaps.
+ */
+static int ftdi_execute_tms(struct jtag_command *cmd)
+{
+       DEBUG_JTAG_IO("TMS: %d bits", cmd->cmd.tms->num_bits);
+
+       /* TODO: Missing tap state tracking, also missing from ft2232.c! */
+       return mpsse_clock_tms_cs_out(mpsse_ctx,
+               cmd->cmd.tms->bits,
+               0,
+               cmd->cmd.tms->num_bits,
+               false,
+               JTAG_MODE);
+}
+
+static int ftdi_execute_pathmove(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+
+       tap_state_t *path = cmd->cmd.pathmove->path;
+       int num_states  = cmd->cmd.pathmove->num_states;
+
+       DEBUG_JTAG_IO("pathmove: %i states, current: %s  end: %s", num_states,
+               tap_state_name(tap_get_state()),
+               tap_state_name(path[num_states-1]));
+
+       int state_count = 0;
+       unsigned bit_count = 0;
+       uint8_t tms_byte = 0;
+
+       DEBUG_JTAG_IO("-");
+
+       /* this loop verifies that the path is legal and logs each state in the path */
+       while (num_states-- && retval == ERROR_OK) {
+
+               /* either TMS=0 or TMS=1 must work ... */
+               if (tap_state_transition(tap_get_state(), false)
+                   == path[state_count])
+                       buf_set_u32(&tms_byte, bit_count++, 1, 0x0);
+               else if (tap_state_transition(tap_get_state(), true)
+                        == path[state_count]) {
+                       buf_set_u32(&tms_byte, bit_count++, 1, 0x1);
+
+                       /* ... or else the caller goofed BADLY */
+               } else {
+                       LOG_ERROR("BUG: %s -> %s isn't a valid "
+                               "TAP state transition",
+                               tap_state_name(tap_get_state()),
+                               tap_state_name(path[state_count]));
+                       exit(-1);
+               }
+
+               tap_set_state(path[state_count]);
+               state_count++;
+
+               if (bit_count == 7 || num_states == 0) {
+                       retval = mpsse_clock_tms_cs_out(mpsse_ctx,
+                                       &tms_byte,
+                                       0,
+                                       bit_count,
+                                       false,
+                                       JTAG_MODE);
+                       bit_count = 0;
+               }
+       }
+       tap_set_end_state(tap_get_state());
+
+       return retval;
+}
+
+static int ftdi_execute_scan(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+
+       DEBUG_JTAG_IO("%s type:%d", cmd->cmd.scan->ir_scan ? "IRSCAN" : "DRSCAN",
+               jtag_scan_type(cmd->cmd.scan));
+
+       if (cmd->cmd.scan->ir_scan) {
+               if (tap_get_state() != TAP_IRSHIFT)
+                       move_to_state(TAP_IRSHIFT);
+       } else {
+               if (tap_get_state() != TAP_DRSHIFT)
+                       move_to_state(TAP_DRSHIFT);
+       }
+
+       ftdi_end_state(cmd->cmd.scan->end_state);
+
+       struct scan_field *field = cmd->cmd.scan->fields;
+       unsigned scan_size = 0;
+
+       for (int i = 0; i < cmd->cmd.scan->num_fields; i++, field++) {
+               scan_size += field->num_bits;
+               DEBUG_JTAG_IO("%s%s field %d/%d %d bits",
+                       field->in_value ? "in" : "",
+                       field->out_value ? "out" : "",
+                       i,
+                       cmd->cmd.scan->num_fields,
+                       field->num_bits);
+
+               if (i == cmd->cmd.scan->num_fields - 1 && tap_get_state() != tap_get_end_state()) {
+                       /* Last field, and we're leaving IRSHIFT/DRSHIFT. Clock last bit during tap
+                        *movement */
+                       mpsse_clock_data(mpsse_ctx,
+                               field->out_value,
+                               0,
+                               field->in_value,
+                               0,
+                               field->num_bits - 1,
+                               JTAG_MODE);
+                       uint8_t last_bit = 0;
+                       if (field->out_value)
+                               bit_copy(&last_bit, 0, field->out_value, field->num_bits - 1, 1);
+                       uint8_t tms_bits = 0x01;
+                       retval = mpsse_clock_tms_cs(mpsse_ctx,
+                                       &tms_bits,
+                                       0,
+                                       field->in_value,
+                                       field->num_bits - 1,
+                                       1,
+                                       last_bit,
+                                       JTAG_MODE);
+                       tap_set_state(tap_state_transition(tap_get_state(), 1));
+                       retval = mpsse_clock_tms_cs_out(mpsse_ctx,
+                                       &tms_bits,
+                                       1,
+                                       1,
+                                       last_bit,
+                                       JTAG_MODE);
+                       tap_set_state(tap_state_transition(tap_get_state(), 0));
+               } else
+                       mpsse_clock_data(mpsse_ctx,
+                               field->out_value,
+                               0,
+                               field->in_value,
+                               0,
+                               field->num_bits,
+                               JTAG_MODE);
+               if (retval != ERROR_OK) {
+                       LOG_ERROR("failed to add field %d in scan", i);
+                       return retval;
+               }
+       }
+
+       if (tap_get_state() != tap_get_end_state())
+               move_to_state(tap_get_end_state());
+
+       DEBUG_JTAG_IO("%s scan, %i bits, end in %s",
+               (cmd->cmd.scan->ir_scan) ? "IR" : "DR", scan_size,
+               tap_state_name(tap_get_end_state()));
+       return retval;
+
+}
+
+static int ftdi_execute_reset(struct jtag_command *cmd)
+{
+       DEBUG_JTAG_IO("reset trst: %i srst %i",
+               cmd->cmd.reset->trst, cmd->cmd.reset->srst);
+
+       if (cmd->cmd.reset->trst == 1
+           || (cmd->cmd.reset->srst
+               && (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
+               tap_set_state(TAP_RESET);
+
+       struct signal *trst = find_signal_by_name("nTRST");
+       if (trst && cmd->cmd.reset->trst == 1) {
+               ftdi_set_signal(trst, '0');
+       } else if (trst && cmd->cmd.reset->trst == 0) {
+               if (jtag_get_reset_config() & RESET_TRST_OPEN_DRAIN)
+                       ftdi_set_signal(trst, 'z');
+               else
+                       ftdi_set_signal(trst, '1');
+       }
+
+       struct signal *srst = find_signal_by_name("nSRST");
+       if (srst && cmd->cmd.reset->srst == 1) {
+               ftdi_set_signal(srst, '0');
+       } else if (srst && cmd->cmd.reset->srst == 0) {
+               if (jtag_get_reset_config() & RESET_SRST_PUSH_PULL)
+                       ftdi_set_signal(srst, '1');
+               else
+                       ftdi_set_signal(srst, 'z');
+       }
+
+       DEBUG_JTAG_IO("trst: %i, srst: %i",
+               cmd->cmd.reset->trst, cmd->cmd.reset->srst);
+       return ERROR_OK;
+}
+
+static int ftdi_execute_sleep(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+
+       DEBUG_JTAG_IO("sleep %" PRIi32, cmd->cmd.sleep->us);
+
+       retval = mpsse_flush(mpsse_ctx);
+       jtag_sleep(cmd->cmd.sleep->us);
+       DEBUG_JTAG_IO("sleep %" PRIi32 " usec while in %s",
+               cmd->cmd.sleep->us,
+               tap_state_name(tap_get_state()));
+       return retval;
+}
+
+static int ftdi_execute_stableclocks(struct jtag_command *cmd)
+{
+       int retval = ERROR_OK;
+
+       /* this is only allowed while in a stable state.  A check for a stable
+        * state was done in jtag_add_clocks()
+        */
+       int num_cycles = cmd->cmd.stableclocks->num_cycles;
+
+       /* 7 bits of either ones or zeros. */
+       uint8_t tms = tap_get_state() == TAP_RESET ? 0x7f : 0x00;
+
+       /* TODO: Use mpsse_clock_data with in=out=0 for this, if TMS can be set to
+        * the correct level and remain there during the scan */
+       while (num_cycles > 0 && retval == ERROR_OK) {
+               /* there are no state transitions in this code, so omit state tracking */
+               unsigned this_len = num_cycles > 7 ? 7 : num_cycles;
+               retval = mpsse_clock_tms_cs_out(mpsse_ctx, &tms, 0, this_len, false, JTAG_MODE);
+               num_cycles -= this_len;
+       }
+
+       DEBUG_JTAG_IO("clocks %i while in %s",
+               cmd->cmd.stableclocks->num_cycles,
+               tap_state_name(tap_get_state()));
+       return retval;
+}
+
+static int ftdi_execute_command(struct jtag_command *cmd)
+{
+       int retval;
+
+       switch (cmd->type) {
+               case JTAG_RESET:
+                       retval = ftdi_execute_reset(cmd);
+                       break;
+               case JTAG_RUNTEST:
+                       retval = ftdi_execute_runtest(cmd);
+                       break;
+               case JTAG_TLR_RESET:
+                       retval = ftdi_execute_statemove(cmd);
+                       break;
+               case JTAG_PATHMOVE:
+                       retval = ftdi_execute_pathmove(cmd);
+                       break;
+               case JTAG_SCAN:
+                       retval = ftdi_execute_scan(cmd);
+                       break;
+               case JTAG_SLEEP:
+                       retval = ftdi_execute_sleep(cmd);
+                       break;
+               case JTAG_STABLECLOCKS:
+                       retval = ftdi_execute_stableclocks(cmd);
+                       break;
+               case JTAG_TMS:
+                       retval = ftdi_execute_tms(cmd);
+                       break;
+               default:
+                       LOG_ERROR("BUG: unknown JTAG command type encountered: %d", cmd->type);
+                       retval = ERROR_JTAG_QUEUE_FAILED;
+                       break;
+       }
+       return retval;
+}
+
+static int ftdi_execute_queue(void)
+{
+       int retval = ERROR_OK;
+
+       /* blink, if the current layout has that feature */
+       struct signal *led = find_signal_by_name("LED");
+       if (led)
+               ftdi_set_signal(led, '1');
+
+       for (struct jtag_command *cmd = jtag_command_queue; cmd; cmd = cmd->next) {
+               /* fill the write buffer with the desired command */
+               if (ftdi_execute_command(cmd) != ERROR_OK)
+                       retval = ERROR_JTAG_QUEUE_FAILED;
+       }
+
+       if (led)
+               ftdi_set_signal(led, '0');
+
+       retval = mpsse_flush(mpsse_ctx);
+       if (retval != ERROR_OK)
+               LOG_ERROR("error while flushing MPSSE queue: %d", retval);
+
+       return retval;
+}
+
+static int ftdi_initialize(void)
+{
+       int retval;
+
+       if (tap_get_tms_path_len(TAP_IRPAUSE, TAP_IRPAUSE) == 7)
+               LOG_DEBUG("ftdi interface using 7 step jtag state transitions");
+       else
+               LOG_DEBUG("ftdi interface using shortest path jtag state transitions");
+
+       for (int i = 0; ftdi_vid[i] || ftdi_pid[i]; i++) {
+               mpsse_ctx = mpsse_open(&ftdi_vid[i], &ftdi_pid[i], ftdi_device_desc,
+                               ftdi_serial, ftdi_channel);
+               if (mpsse_ctx)
+                       break;
+       }
+
+       if (!mpsse_ctx)
+               return ERROR_JTAG_INIT_FAILED;
+
+       retval = mpsse_set_data_bits_low_byte(mpsse_ctx, output & 0xff, direction & 0xff);
+       if (retval == ERROR_OK)
+               retval = mpsse_set_data_bits_high_byte(mpsse_ctx, output >> 8, direction >> 8);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("couldn't initialize FTDI with 'JTAGkey' layout");
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
+       retval = mpsse_loopback_config(mpsse_ctx, false);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("couldn't write to FTDI to disable loopback");
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
+       return mpsse_flush(mpsse_ctx);
+}
+
+static int ftdi_quit(void)
+{
+       mpsse_close(mpsse_ctx);
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_device_desc_command)
+{
+       if (CMD_ARGC == 1) {
+               if (ftdi_device_desc)
+                       free(ftdi_device_desc);
+               ftdi_device_desc = strdup(CMD_ARGV[0]);
+       } else {
+               LOG_ERROR("expected exactly one argument to ftdi_device_desc <description>");
+       }
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_serial_command)
+{
+       if (CMD_ARGC == 1) {
+               if (ftdi_serial)
+                       free(ftdi_serial);
+               ftdi_serial = strdup(CMD_ARGV[0]);
+       } else {
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_channel_command)
+{
+       if (CMD_ARGC == 1)
+               COMMAND_PARSE_NUMBER(u8, CMD_ARGV[0], ftdi_channel);
+       else
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_layout_init_command)
+{
+       if (CMD_ARGC != 2)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], output);
+       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[1], direction);
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_layout_signal_command)
+{
+       if (CMD_ARGC < 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       bool invert_data = false;
+       uint16_t data_mask = 0;
+       bool invert_oe = false;
+       uint16_t oe_mask = 0;
+       for (unsigned i = 1; i < CMD_ARGC; i += 2) {
+               if (strcmp("-data", CMD_ARGV[i]) == 0) {
+                       invert_data = false;
+                       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], data_mask);
+               } else if (strcmp("-ndata", CMD_ARGV[i]) == 0) {
+                       invert_data = true;
+                       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], data_mask);
+               } else if (strcmp("-oe", CMD_ARGV[i]) == 0) {
+                       invert_oe = false;
+                       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], oe_mask);
+               } else if (strcmp("-noe", CMD_ARGV[i]) == 0) {
+                       invert_oe = true;
+                       COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], oe_mask);
+               } else {
+                       LOG_ERROR("unknown option '%s'", CMD_ARGV[i]);
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+       }
+
+       struct signal *sig;
+       sig = find_signal_by_name(CMD_ARGV[0]);
+       if (!sig)
+               sig = create_signal(CMD_ARGV[0]);
+       if (!sig) {
+               LOG_ERROR("failed to create signal %s", CMD_ARGV[0]);
+               return ERROR_FAIL;
+       }
+
+       sig->invert_data = invert_data;
+       sig->data_mask = data_mask;
+       sig->invert_oe = invert_oe;
+       sig->oe_mask = oe_mask;
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(ftdi_handle_set_signal_command)
+{
+       if (CMD_ARGC < 2)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       struct signal *sig;
+       sig = find_signal_by_name(CMD_ARGV[0]);
+       if (!sig) {
+               LOG_ERROR("interface configuration doesn't define signal '%s'", CMD_ARGV[0]);
+               return ERROR_FAIL;
+       }
+
+       switch (*CMD_ARGV[1]) {
+       case '0':
+       case '1':
+       case 'z':
+       case 'Z':
+               /* single character level specifier only */
+               if (CMD_ARGV[1][1] == '\0') {
+                       ftdi_set_signal(sig, *CMD_ARGV[1]);
+                       break;
+               }
+       default:
+               LOG_ERROR("unknown signal level '%s', use 0, 1 or z", CMD_ARGV[1]);
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       return mpsse_flush(mpsse_ctx);
+}
+
+COMMAND_HANDLER(ftdi_handle_vid_pid_command)
+{
+       if (CMD_ARGC > MAX_USB_IDS * 2) {
+               LOG_WARNING("ignoring extra IDs in ftdi_vid_pid "
+                       "(maximum is %d pairs)", MAX_USB_IDS);
+               CMD_ARGC = MAX_USB_IDS * 2;
+       }
+       if (CMD_ARGC < 2 || (CMD_ARGC & 1)) {
+               LOG_WARNING("incomplete ftdi_vid_pid configuration directive");
+               if (CMD_ARGC < 2)
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               /* remove the incomplete trailing id */
+               CMD_ARGC -= 1;
+       }
+
+       unsigned i;
+       for (i = 0; i < CMD_ARGC; i += 2) {
+               COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i], ftdi_vid[i >> 1]);
+               COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], ftdi_pid[i >> 1]);
+       }
+
+       /*
+        * Explicitly terminate, in case there are multiples instances of
+        * ftdi_vid_pid.
+        */
+       ftdi_vid[i >> 1] = ftdi_pid[i >> 1] = 0;
+
+       return ERROR_OK;
+}
+
+static const struct command_registration ftdi_command_handlers[] = {
+       {
+               .name = "ftdi_device_desc",
+               .handler = &ftdi_handle_device_desc_command,
+               .mode = COMMAND_CONFIG,
+               .help = "set the USB device description of the FTDI device",
+               .usage = "description_string",
+       },
+       {
+               .name = "ftdi_serial",
+               .handler = &ftdi_handle_serial_command,
+               .mode = COMMAND_CONFIG,
+               .help = "set the serial number of the FTDI device",
+               .usage = "serial_string",
+       },
+       {
+               .name = "ftdi_channel",
+               .handler = &ftdi_handle_channel_command,
+               .mode = COMMAND_CONFIG,
+               .help = "set the channel of the FTDI device that is used as JTAG",
+               .usage = "(0-3)",
+       },
+       {
+               .name = "ftdi_layout_init",
+               .handler = &ftdi_handle_layout_init_command,
+               .mode = COMMAND_CONFIG,
+               .help = "initialize the FTDI GPIO signals used "
+                       "to control output-enables and reset signals",
+               .usage = "data direction",
+       },
+       {
+               .name = "ftdi_layout_signal",
+               .handler = &ftdi_handle_layout_signal_command,
+               .mode = COMMAND_ANY,
+               .help = "define a signal controlled by one or more FTDI GPIO as data "
+                       "and/or output enable",
+               .usage = "name [-data mask|-ndata mask] [-oe mask|-noe mask]",
+       },
+       {
+               .name = "ftdi_set_signal",
+               .handler = &ftdi_handle_set_signal_command,
+               .mode = COMMAND_EXEC,
+               .help = "control a layout-specific signal",
+               .usage = "name (1|0|z)",
+       },
+       {
+               .name = "ftdi_vid_pid",
+               .handler = &ftdi_handle_vid_pid_command,
+               .mode = COMMAND_CONFIG,
+               .help = "the vendor ID and product ID of the FTDI device",
+               .usage = "(vid pid)* ",
+       },
+       COMMAND_REGISTRATION_DONE
+};
+
+struct jtag_interface ftdi_interface = {
+       .name = "ftdi",
+       .supported = DEBUG_CAP_TMS_SEQ,
+       .commands = ftdi_command_handlers,
+       .transports = jtag_only,
+
+       .init = ftdi_initialize,
+       .quit = ftdi_quit,
+       .speed = ftdi_speed,
+       .speed_div = ftdi_speed_div,
+       .khz = ftdi_khz,
+       .execute_queue = ftdi_execute_queue,
+};