ftdi.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/**************************************************************************
*   Copyright (C) 2012 by Andreas Fritiofson                              *
*   andreas.fritiofson@gmail.com                                          *
***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
/* project specific includes */
#include <jtag/adapter.h>
#include <jtag/interface.h>
#include <jtag/swd.h>
#include <transport/transport.h>
#include <helper/time_support.h>
#include <helper/log.h>
#include <helper/nvp.h>
 
#if IS_CYGWIN == 1
#include <windows.h>
#endif
 
#include <assert.h>
 
/* FTDI access library includes */
#include "mpsse.h"
 
#if BUILD_FTDI_CJTAG == 1
#define DO_CLOCK_DATA clock_data
#define DO_CLOCK_TMS_CS clock_tms_cs
#define DO_CLOCK_TMS_CS_OUT clock_tms_cs_out
#else
#define DO_CLOCK_DATA mpsse_clock_data
#define DO_CLOCK_TMS_CS mpsse_clock_tms_cs
#define DO_CLOCK_TMS_CS_OUT mpsse_clock_tms_cs_out
#endif
 
#define JTAG_MODE (LSB_FIRST | POS_EDGE_IN | NEG_EDGE_OUT)
#define JTAG_MODE_ALT (LSB_FIRST | NEG_EDGE_IN | NEG_EDGE_OUT)
#define SWD_MODE (LSB_FIRST | POS_EDGE_IN | NEG_EDGE_OUT)
 
static char *ftdi_device_desc;
static uint8_t ftdi_channel;
static uint8_t ftdi_jtag_mode = JTAG_MODE;
 
static bool swd_mode;
 
#if BUILD_FTDI_CJTAG == 1
#define ESCAPE_SEQ_OAC_BIT2 28
 
static void cjtag_reset_online_activate(void);
 
/*
  The cJTAG 2-wire OScan1 protocol, in lieu of 4-wire JTAG, is a configuration option
  for some SoCs. An FTDI-based adapter that can be configured to appropriately drive
  the bidirectional pin TMSC is able to drive OScan1 protocol.  For example, an Olimex
  ARM-USB-TINY-H with the ARM-JTAG-SWD adapter, connected to a cJTAG-enabled
  target board is such a topology.  A TCK cycle with TMS=1/TDI=N translates to a TMSC
  output of N, and a TCK cycle with TMS=0 translates to a TMSC input from the target back
  to the adapter/probe.  The OScan1 protocol uses 3 TCK cycles to generate the data flow
  that is equivalent to that of a single TCK cycle in 4-wire JTAG. The OScan1-related
  code in this module translates IR/DR scan commanads and JTAG state traversal commands
  to the two-wire clocking and signaling of OScan1 protocol, if placed into OScan1 mode
  during initialization.
*/
static void oscan1_mpsse_clock_data(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
                    unsigned int in_offset, unsigned int length, uint8_t mode);
static void oscan1_mpsse_clock_tms_cs(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
                      unsigned int in_offset, unsigned int length, bool tdi, uint8_t mode);
static void oscan1_mpsse_clock_tms_cs_out(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset,
                      unsigned int length, bool tdi, uint8_t mode);
 
static bool oscan1_mode;
 
/*
  The cJTAG 4-wire JScan3 allows to use standard JTAG protocol with cJTAG hardware
*/
static bool jscan3_mode;
#endif
 
#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 input_mask;
    uint16_t oe_mask;
    bool invert_data;
    bool invert_input;
    bool invert_oe;
    struct signal *next;
};
 
static struct signal *signals;
 
/* FIXME: Where to store per-instance data? We need an SWD context. */
static struct swd_cmd_queue_entry {
    uint8_t cmd;
    uint32_t *dst;
    uint8_t trn_ack_data_parity_trn[DIV_ROUND_UP(4 + 3 + 32 + 1 + 4, 8)];
} *swd_cmd_queue;
static size_t swd_cmd_queue_length;
static size_t swd_cmd_queue_alloced;
static int queued_retval;
static int freq;
 
static uint16_t output;
static uint16_t direction;
static uint16_t jtag_output_init;
static uint16_t jtag_direction_init;
 
static int ftdi_swd_switch_seq(enum swd_special_seq seq);
 
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)
        return NULL;
 
    (*psig)->name = strdup(name);
    if (!(*psig)->name) {
        free(*psig);
        *psig = NULL;
    }
    return *psig;
}
 
static int ftdi_set_signal(const struct signal *s, char value)
{
    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:
        LOG_ERROR("invalid signal level specifier \'%c\'(0x%02x)", value, value);
        return ERROR_FAIL;
    }
 
    uint16_t old_output = output;
    uint16_t old_direction = direction;
 
    output = data ? output | s->data_mask : output & ~s->data_mask;
    if (s->oe_mask == s->data_mask)
        direction = oe ? direction | s->oe_mask : direction & ~s->oe_mask;
    else
        output = oe ? output | s->oe_mask : output & ~s->oe_mask;
 
    if ((output & 0xff) != (old_output & 0xff) || (direction & 0xff) != (old_direction & 0xff))
        mpsse_set_data_bits_low_byte(mpsse_ctx, output & 0xff, direction & 0xff);
    if ((output >> 8 != old_output >> 8) || (direction >> 8 != old_direction >> 8))
        mpsse_set_data_bits_high_byte(mpsse_ctx, output >> 8, direction >> 8);
 
    return ERROR_OK;
}
 
static int ftdi_get_signal(const struct signal *s, uint16_t *value_out)
{
    uint8_t data_low = 0;
    uint8_t data_high = 0;
 
    if (s->input_mask == 0) {
        LOG_ERROR("interface doesn't provide signal '%s'", s->name);
        return ERROR_FAIL;
    }
 
    if (s->input_mask & 0xff)
        mpsse_read_data_bits_low_byte(mpsse_ctx, &data_low);
    if (s->input_mask >> 8)
        mpsse_read_data_bits_high_byte(mpsse_ctx, &data_high);
 
    mpsse_flush(mpsse_ctx);
 
    *value_out = (((uint16_t)data_high) << 8) | data_low;
 
    if (s->invert_input)
        *value_out = ~(*value_out);
 
    *value_out &= s->input_mask;
 
    return ERROR_OK;
}
 
#if BUILD_FTDI_CJTAG == 1
static void clock_data(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
             unsigned int in_offset, unsigned int length, uint8_t mode)
{
    if (oscan1_mode)
        oscan1_mpsse_clock_data(ctx, out, out_offset, in, in_offset, length, mode);
    else
        mpsse_clock_data(ctx, out, out_offset, in, in_offset, length, mode);
}
 
static void clock_tms_cs(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
               unsigned int in_offset, unsigned int length, bool tdi, uint8_t mode)
{
    if (oscan1_mode)
        oscan1_mpsse_clock_tms_cs(ctx, out, out_offset, in, in_offset, length, tdi, mode);
    else
        mpsse_clock_tms_cs(ctx, out, out_offset, in, in_offset, length, tdi, mode);
}
 
static void clock_tms_cs_out(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset,
               unsigned int length, bool tdi, uint8_t mode)
{
    if (oscan1_mode)
        oscan1_mpsse_clock_tms_cs_out(ctx, out, out_offset, length, tdi, mode);
    else
        mpsse_clock_tms_cs_out(ctx, out, out_offset, length, tdi, mode);
}
#endif
 
static void move_to_state(enum tap_state goal_state)
{
    enum tap_state 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 */
    uint8_t tms_bits  = tap_get_tms_path(start_state, goal_state);
    int tms_count = tap_get_tms_path_len(start_state, goal_state);
    assert(tms_count <= 8);
 
    LOG_DEBUG_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));
 
    DO_CLOCK_TMS_CS_OUT(mpsse_ctx,
        &tms_bits,
        0,
        tms_count,
        false,
        ftdi_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;
    }
 
    if (!swd_mode && speed >= 10000000 && ftdi_jtag_mode != JTAG_MODE_ALT)
        LOG_INFO("ftdi: if you experience problems at higher adapter clocks, try "
             "the command \"ftdi tdo_sample_edge falling\"");
    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)
{
    if (khz == 0 && !mpsse_is_high_speed(mpsse_ctx)) {
        LOG_DEBUG("RCLK not supported");
        return ERROR_FAIL;
    }
 
    *jtag_speed = khz * 1000;
    return ERROR_OK;
}
 
static void ftdi_end_state(enum tap_state 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 void ftdi_execute_runtest(struct jtag_command *cmd)
{
    uint8_t zero = 0;
 
    LOG_DEBUG_IO("runtest %u 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 */
    unsigned int i = cmd->cmd.runtest->num_cycles;
    while (i > 0) {
        /* there are no state transitions in this code, so omit state tracking */
        unsigned int this_len = i > 7 ? 7 : i;
        DO_CLOCK_TMS_CS_OUT(mpsse_ctx, &zero, 0, this_len, false, ftdi_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());
 
    LOG_DEBUG_IO("runtest: %u, end in %s",
        cmd->cmd.runtest->num_cycles,
        tap_state_name(tap_get_end_state()));
}
 
static void ftdi_execute_statemove(struct jtag_command *cmd)
{
    LOG_DEBUG_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());
}
 
static void ftdi_execute_tms(struct jtag_command *cmd)
{
    LOG_DEBUG_IO("TMS: %u bits", cmd->cmd.tms->num_bits);
 
    /* TODO: Missing tap state tracking, also missing from ft2232.c! */
    DO_CLOCK_TMS_CS_OUT(mpsse_ctx,
        cmd->cmd.tms->bits,
        0,
        cmd->cmd.tms->num_bits,
        false,
        ftdi_jtag_mode);
}
 
static void ftdi_execute_pathmove(struct jtag_command *cmd)
{
    enum tap_state *path = cmd->cmd.pathmove->path;
    unsigned int num_states  = cmd->cmd.pathmove->num_states;
 
    LOG_DEBUG_IO("pathmove: %u 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 int bit_count = 0;
    uint8_t tms_byte = 0;
 
    LOG_DEBUG_IO("-");
 
    /* this loop verifies that the path is legal and logs each state in the path */
    while (num_states--) {
 
        /* 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) {
            DO_CLOCK_TMS_CS_OUT(mpsse_ctx,
                    &tms_byte,
                    0,
                    bit_count,
                    false,
                    ftdi_jtag_mode);
            bit_count = 0;
        }
    }
    tap_set_end_state(tap_get_state());
}
 
static void ftdi_execute_scan(struct jtag_command *cmd)
{
    LOG_DEBUG_IO("%s type:%d", cmd->cmd.scan->ir_scan ? "IRSCAN" : "DRSCAN",
        jtag_scan_type(cmd->cmd.scan));
 
    /* Make sure there are no trailing fields with num_bits == 0, or the logic below will fail. */
    while (cmd->cmd.scan->num_fields > 0
            && cmd->cmd.scan->fields[cmd->cmd.scan->num_fields - 1].num_bits == 0) {
        cmd->cmd.scan->num_fields--;
        LOG_DEBUG_IO("discarding trailing empty field");
    }
 
    if (!cmd->cmd.scan->num_fields) {
        LOG_DEBUG_IO("empty scan, doing nothing");
        return;
    }
 
    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 int scan_size = 0;
 
    for (unsigned int i = 0; i < cmd->cmd.scan->num_fields; i++, field++) {
        scan_size += field->num_bits;
        LOG_DEBUG_IO("%s%s field %u/%u %u 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. This last field can't have length zero, it was checked above. */
            DO_CLOCK_DATA(mpsse_ctx,
                field->out_value,
                0,
                field->in_value,
                0,
                field->num_bits - 1,
                ftdi_jtag_mode);
            uint8_t last_bit = 0;
            if (field->out_value)
                bit_copy(&last_bit, 0, field->out_value, field->num_bits - 1, 1);
 
            /* If endstate is TAP_IDLE, clock out 1-1-0 (->EXIT1 ->UPDATE ->IDLE)
             * Otherwise, clock out 1-0 (->EXIT1 ->PAUSE)
             */
            uint8_t tms_bits = 0x03;
            DO_CLOCK_TMS_CS(mpsse_ctx,
                    &tms_bits,
                    0,
                    field->in_value,
                    field->num_bits - 1,
                    1,
                    last_bit,
                    ftdi_jtag_mode);
            tap_set_state(tap_state_transition(tap_get_state(), 1));
            if (tap_get_end_state() == TAP_IDLE) {
                DO_CLOCK_TMS_CS_OUT(mpsse_ctx,
                        &tms_bits,
                        1,
                        2,
                        last_bit,
                        ftdi_jtag_mode);
                tap_set_state(tap_state_transition(tap_get_state(), 1));
                tap_set_state(tap_state_transition(tap_get_state(), 0));
            } else {
                DO_CLOCK_TMS_CS_OUT(mpsse_ctx,
                        &tms_bits,
                        2,
                        1,
                        last_bit,
                        ftdi_jtag_mode);
                tap_set_state(tap_state_transition(tap_get_state(), 0));
            }
        } else
            DO_CLOCK_DATA(mpsse_ctx,
                field->out_value,
                0,
                field->in_value,
                0,
                field->num_bits,
                ftdi_jtag_mode);
    }
 
    if (tap_get_state() != tap_get_end_state())
        move_to_state(tap_get_end_state());
 
    LOG_DEBUG_IO("%s scan, %i bits, end in %s",
        (cmd->cmd.scan->ir_scan) ? "IR" : "DR", scan_size,
        tap_state_name(tap_get_end_state()));
}
 
static int ftdi_reset(int trst, int srst)
{
    struct signal *sig_ntrst = find_signal_by_name("nTRST");
    struct signal *sig_nsrst = find_signal_by_name("nSRST");
 
    LOG_DEBUG_IO("reset trst: %i srst %i", trst, srst);
 
    if (!swd_mode) {
        if (trst == 1) {
            if (sig_ntrst)
                ftdi_set_signal(sig_ntrst, '0');
            else
                LOG_ERROR("Can't assert TRST: nTRST signal is not defined");
        } else if (sig_ntrst && jtag_get_reset_config() & RESET_HAS_TRST &&
                trst == 0) {
            if (jtag_get_reset_config() & RESET_TRST_OPEN_DRAIN)
                ftdi_set_signal(sig_ntrst, 'z');
            else
                ftdi_set_signal(sig_ntrst, '1');
        }
    }
 
    if (srst == 1) {
        if (sig_nsrst)
            ftdi_set_signal(sig_nsrst, '0');
        else
            LOG_ERROR("Can't assert SRST: nSRST signal is not defined");
    } else if (sig_nsrst && jtag_get_reset_config() & RESET_HAS_SRST &&
            srst == 0) {
        if (jtag_get_reset_config() & RESET_SRST_PUSH_PULL)
            ftdi_set_signal(sig_nsrst, '1');
        else
            ftdi_set_signal(sig_nsrst, 'z');
    }
 
    return mpsse_flush(mpsse_ctx);
}
 
static void ftdi_execute_sleep(struct jtag_command *cmd)
{
    LOG_DEBUG_IO("sleep %" PRIu32, cmd->cmd.sleep->us);
 
    mpsse_flush(mpsse_ctx);
    jtag_sleep(cmd->cmd.sleep->us);
    LOG_DEBUG_IO("sleep %" PRIu32 " usec while in %s",
        cmd->cmd.sleep->us,
        tap_state_name(tap_get_state()));
}
 
static void ftdi_execute_stableclocks(struct jtag_command *cmd)
{
    /* this is only allowed while in a stable state.  A check for a stable
     * state was done in jtag_add_clocks()
     */
    unsigned 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) {
        /* there are no state transitions in this code, so omit state tracking */
        unsigned int this_len = num_cycles > 7 ? 7 : num_cycles;
        DO_CLOCK_TMS_CS_OUT(mpsse_ctx, &tms, 0, this_len, false, ftdi_jtag_mode);
        num_cycles -= this_len;
    }
 
    LOG_DEBUG_IO("clocks %u while in %s",
        cmd->cmd.stableclocks->num_cycles,
        tap_state_name(tap_get_state()));
}
 
static void ftdi_execute_command(struct jtag_command *cmd)
{
    switch (cmd->type) {
#if BUILD_FTDI_CJTAG == 1
    case JTAG_RESET:
        if (cmd->cmd.reset->trst)
            cjtag_reset_online_activate(); /* put the target (back) into selected cJTAG mode */
        break;
#endif
    case JTAG_RUNTEST:
        ftdi_execute_runtest(cmd);
        break;
    case JTAG_TLR_RESET:
#if BUILD_FTDI_CJTAG == 1
        cjtag_reset_online_activate(); /* put the target (back) into selected cJTAG mode */
#endif
        ftdi_execute_statemove(cmd);
        break;
    case JTAG_PATHMOVE:
        ftdi_execute_pathmove(cmd);
        break;
    case JTAG_SCAN:
        ftdi_execute_scan(cmd);
        break;
    case JTAG_SLEEP:
        ftdi_execute_sleep(cmd);
        break;
    case JTAG_STABLECLOCKS:
        ftdi_execute_stableclocks(cmd);
        break;
    case JTAG_TMS:
        ftdi_execute_tms(cmd);
        break;
    default:
        LOG_ERROR("BUG: unknown JTAG command type encountered: %d", cmd->type);
        break;
    }
}
 
static int ftdi_execute_queue(struct jtag_command *cmd_queue)
{
    /* 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 = cmd_queue; cmd; cmd = cmd->next) {
        /* fill the write buffer with the desired command */
        ftdi_execute_command(cmd);
    }
 
    if (led)
        ftdi_set_signal(led, '0');
 
    int 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)
{
    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");
 
    if (!ftdi_vid[0] && !ftdi_pid[0]) {
        LOG_ERROR("Please specify ftdi vid_pid");
        return ERROR_JTAG_INIT_FAILED;
    }
 
    mpsse_ctx = mpsse_open(ftdi_vid, ftdi_pid, ftdi_device_desc,
                adapter_get_required_serial(), adapter_usb_get_location(), ftdi_channel);
    if (!mpsse_ctx)
        return ERROR_JTAG_INIT_FAILED;
 
    output = jtag_output_init;
    direction = jtag_direction_init;
 
    if (swd_mode) {
        struct signal *sig = find_signal_by_name("SWD_EN");
        if (!sig) {
            LOG_ERROR("SWD mode is active but SWD_EN signal is not defined");
            return ERROR_JTAG_INIT_FAILED;
        }
        /* A dummy SWD_EN would have zero mask */
        if (sig->data_mask)
            ftdi_set_signal(sig, '1');
#if BUILD_FTDI_CJTAG == 1
    } else if (oscan1_mode || jscan3_mode) {
        struct signal *sig = find_signal_by_name("JTAG_SEL");
        if (!sig) {
            LOG_ERROR("A cJTAG mode is active but JTAG_SEL signal is not defined");
            return ERROR_JTAG_INIT_FAILED;
        }
        /* A dummy JTAG_SEL would have zero mask */
        if (sig->data_mask) {
            ftdi_set_signal(sig, '0');
        } else if (jscan3_mode) {
            LOG_ERROR("In JScan3 mode JTAG_SEL signal cannot be dummy, data mask needed");
            return ERROR_JTAG_INIT_FAILED;
        }
#endif
    }
 
    mpsse_set_data_bits_low_byte(mpsse_ctx, output & 0xff, direction & 0xff);
    mpsse_set_data_bits_high_byte(mpsse_ctx, output >> 8, direction >> 8);
 
    mpsse_loopback_config(mpsse_ctx, false);
 
    freq = mpsse_set_frequency(mpsse_ctx, adapter_get_speed_khz() * 1000);
 
    return mpsse_flush(mpsse_ctx);
}
 
static int ftdi_quit(void)
{
    mpsse_close(mpsse_ctx);
 
    struct signal *sig = signals;
    while (sig) {
        struct signal *next = sig->next;
        free((void *)sig->name);
        free(sig);
        sig = next;
    }
 
    free(ftdi_device_desc);
 
    free(swd_cmd_queue);
 
    return ERROR_OK;
}
 
#if BUILD_FTDI_CJTAG == 1
static void oscan1_mpsse_clock_data(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
             unsigned int in_offset, unsigned int length, uint8_t mode)
{
    static const uint8_t zero;
    static const uint8_t one = 1;
 
    struct signal *tmsc_en = find_signal_by_name("TMSC_EN");
 
    LOG_DEBUG_IO("%sout %d bits", in ? "in" : "", length);
 
    for (unsigned int i = 0; i < length; i++) {
        int bitnum;
        uint8_t bit;
 
        /* OScan1 uses 3 separate clocks */
 
        /* drive TMSC to the *negation* of the desired TDI value */
        bitnum = out_offset + i;
        bit = out ? ((out[bitnum / 8] >> (bitnum % 8)) & 0x1) : 0;
 
        /* Try optimized case first: if desired TDI bit is 1, then we
           can fuse what would otherwise be the first two MPSSE commands */
        if (bit) {
            const uint8_t tmsbits = 0x3;  /* 1, 1 */
            mpsse_clock_tms_cs_out(mpsse_ctx, &tmsbits, 0, 2, false, mode);
        } else {
            /* Can't fuse because TDI varies; less efficient */
            mpsse_clock_tms_cs_out(mpsse_ctx, &one, 0, 1, bit ? 0 : 1, mode);
 
            /* drive TMSC to desired TMS value (always zero in this context) */
            mpsse_clock_tms_cs_out(mpsse_ctx, &one, 0, 1, false, mode);
        }
 
        if (tmsc_en)
            ftdi_set_signal(tmsc_en, '0'); /* put TMSC in high impedance */
 
        /* drive another TCK without driving TMSC (TDO cycle) */
        mpsse_clock_tms_cs(mpsse_ctx, &zero, 0, in, in_offset + i, 1, false, mode);
 
        if (tmsc_en)
            ftdi_set_signal(tmsc_en, '1'); /* drive again TMSC */
    }
}
 
static void oscan1_mpsse_clock_tms_cs(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset, uint8_t *in,
               unsigned int in_offset, unsigned int length, bool tdi, uint8_t mode)
{
    static const uint8_t zero;
    static const uint8_t one = 1;
 
    struct signal *tmsc_en = find_signal_by_name("TMSC_EN");
 
    LOG_DEBUG_IO("%sout %d bits, tdi=%d", in ? "in" : "", length, tdi);
 
    for (unsigned int i = 0; i < length; i++) {
        int bitnum;
        uint8_t tmsbit;
        uint8_t tdibit;
 
        /* OScan1 uses 3 separate clocks */
 
        /* drive TMSC to the *negation* of the desired TDI value */
        tdibit = tdi ? 0 : 1;
 
        /* drive TMSC to desired TMS value */
        bitnum = out_offset + i;
        tmsbit = ((out[bitnum / 8] >> (bitnum % 8)) & 0x1);
 
        if (tdibit == tmsbit) {
            /* Can squash into a single MPSSE command */
            const uint8_t tmsbits = 0x3;
            mpsse_clock_tms_cs_out(mpsse_ctx, &tmsbits, 0, 2, tdibit, mode);
        } else {
            /* Unoptimized case, can't formulate with a single command */
            mpsse_clock_tms_cs_out(mpsse_ctx, &one, 0, 1, tdibit, mode);
            mpsse_clock_tms_cs_out(mpsse_ctx, &one, 0, 1, (tmsbit != 0), mode);
        }
 
        if (tmsc_en)
            ftdi_set_signal(tmsc_en, '0'); /* put TMSC in high impedance */
 
        /* drive another TCK without driving TMSC (TDO cycle) */
        mpsse_clock_tms_cs(mpsse_ctx, &zero, 0, in, in_offset + i, 1, false, mode);
 
        if (tmsc_en)
            ftdi_set_signal(tmsc_en, '1'); /* drive again TMSC */
    }
}
 
static void oscan1_mpsse_clock_tms_cs_out(struct mpsse_ctx *ctx, const uint8_t *out, unsigned int out_offset,
               unsigned int length, bool tdi, uint8_t mode)
{
    oscan1_mpsse_clock_tms_cs(ctx, out, out_offset, 0, 0, length, tdi, mode);
}
 
static void cjtag_set_tck_tms_tdi(struct signal *tck, char tckvalue, struct signal *tms,
                   char tmsvalue, struct signal *tdi, char tdivalue)
{
    ftdi_set_signal(tms, tmsvalue);
    ftdi_set_signal(tdi, tdivalue);
    ftdi_set_signal(tck, tckvalue);
}
 
static void cjtag_reset_online_activate(void)
{
    /* After TAP reset, the cJTAG-to-JTAG adapter is in offline and
    non-activated state. Escape sequences are needed to bring the
    TAP online and activated into the desired working mode. */
 
    struct signal *tck = find_signal_by_name("TCK");
    struct signal *tdi = find_signal_by_name("TDI");
    struct signal *tms = find_signal_by_name("TMS");
    struct signal *tdo = find_signal_by_name("TDO");
    struct signal *tmsc_en = find_signal_by_name("TMSC_EN");
    uint16_t tdovalue;
 
    static struct {
        int8_t tck;
        int8_t tms;
        int8_t tdi;
    } sequence[] = {
        /* TCK=0, TMS=1, TDI=0 (drive TMSC to 0 baseline) */
        {'0', '1', '0'},
 
        /* Drive cJTAG escape sequence for TAP reset - 8 TMSC edges */
        /* TCK=1, TMS=1, TDI=0 (rising edge of TCK with TMSC still 0) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK with TMSC still 0) */
        {'0', '1', '0'},
 
        /* 3 TCK pulses for padding */
        /* TCK=1, TMS=1, TDI=0 (drive rising TCK edge) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (drive falling TCK edge) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (drive rising TCK edge) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (drive falling TCK edge) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (drive rising TCK edge) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (drive falling TCK edge) */
        {'0', '1', '0'},
 
        /* Drive cJTAG escape sequence for SELECT */
        /* TCK=1, TMS=1, TDI=0 (rising edge of TCK with TMSC still 0, TAP reset that was just setup occurs here too) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=1, TMS=1, TDI=1 (drive rising TMSC edge) */
        {'1', '1', '1'},
        /* TCK=1, TMS=1, TDI=0 (drive falling TMSC edge) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK with TMSC still 0) */
        {'0', '1', '0'},
 
        /* Drive cJTAG escape sequence for OScan1 activation -- OAC = 1100 -> 2 wires -- */
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK with TMSC still 0... online mode activated... also OAC bit0==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... OAC bit1==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=1 (falling edge TCK) */
        {'0', '1', '1'},
        /* TCK=1, TMS=1, TDI=1 (rising edge TCK... OAC bit2==1) */
        {'1', '1', '1'},
        /* TCK=0, TMS=1, TDI=1 (falling edge TCK, TMSC stays high) */
        {'0', '1', '1'},
        /* TCK=1, TMS=1, TDI=1 (rising edge TCK... OAC bit3==1) */
        {'1', '1', '1'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... EC bit0==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... EC bit1==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... EC bit2==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=1 (falling edge TCK) */
        {'0', '1', '1'},
        /* TCK=1, TMS=1, TDI=1 (rising edge TCK... EC bit3==1) */
        {'1', '1', '1'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... CP bit0==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... CP bit1==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... CP bit2==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
        /* TCK=1, TMS=1, TDI=0 (rising edge TCK... CP bit3==0) */
        {'1', '1', '0'},
        /* TCK=0, TMS=1, TDI=0 (falling edge TCK) */
        {'0', '1', '0'},
    };
 
    if (!oscan1_mode && !jscan3_mode)
        return; /* Nothing to do */
 
    if (oscan1_mode && jscan3_mode) {
        LOG_ERROR("Both oscan1_mode and jscan3_mode are \"on\". At most one of them can be enabled.");
        return;
    }
 
    if (!tck) {
        LOG_ERROR("Can't run cJTAG online/activate escape sequences: TCK signal is not defined");
        return;
    }
 
    if (!tdi) {
        LOG_ERROR("Can't run cJTAG online/activate escape sequences: TDI signal is not defined");
        return;
    }
 
    if (!tms) {
        LOG_ERROR("Can't run cJTAG online/activate escape sequences: TMS signal is not defined");
        return;
    }
 
    if (!tdo) {
        LOG_ERROR("Can't run cJTAG online/activate escape sequences: TDO signal is not defined");
        return;
    }
 
    if (jscan3_mode) {
        /* Update the sequence above to enable JScan3 instead of OScan1 */
        sequence[ESCAPE_SEQ_OAC_BIT2].tdi = '0';
        sequence[ESCAPE_SEQ_OAC_BIT2 + 1].tdi = '0';
    }
 
    /* if defined TMSC_EN, replace tms with it */
    if (tmsc_en)
        tms = tmsc_en;
 
    /* Send the sequence to the adapter */
    for (size_t i = 0; i < ARRAY_SIZE(sequence); i++)
        cjtag_set_tck_tms_tdi(tck, sequence[i].tck, tms, sequence[i].tms, tdi, sequence[i].tdi);
 
    /* If JScan3 mode, configure cJTAG adapter to 4-wire */
    if (jscan3_mode)
        ftdi_set_signal(find_signal_by_name("JTAG_SEL"), '1');
 
    ftdi_get_signal(tdo, &tdovalue);  /* Just to force a flush */
}
#endif /* #if BUILD_FTDI_CJTAG == 1 */
 
COMMAND_HANDLER(ftdi_handle_device_desc_command)
{
    if (CMD_ARGC == 1) {
        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_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], jtag_output_init);
    COMMAND_PARSE_NUMBER(u16, CMD_ARGV[1], jtag_direction_init);
 
    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_input = false;
    uint16_t input_mask = 0;
    bool invert_oe = false;
    uint16_t oe_mask = 0;
    for (unsigned int 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("-input", CMD_ARGV[i]) == 0) {
            invert_input = false;
            COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], input_mask);
        } else if (strcmp("-ninput", CMD_ARGV[i]) == 0) {
            invert_input = true;
            COMMAND_PARSE_NUMBER(u16, CMD_ARGV[i + 1], input_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 if (!strcmp("-alias", CMD_ARGV[i]) ||
               !strcmp("-nalias", CMD_ARGV[i])) {
            if (!strcmp("-nalias", CMD_ARGV[i])) {
                invert_data = true;
                invert_input = true;
            }
            struct signal *sig = find_signal_by_name(CMD_ARGV[i + 1]);
            if (!sig) {
                LOG_ERROR("signal %s is not defined", CMD_ARGV[i + 1]);
                return ERROR_FAIL;
            }
            data_mask = sig->data_mask;
            input_mask = sig->input_mask;
            oe_mask = sig->oe_mask;
            invert_input ^= sig->invert_input;
            invert_oe = sig->invert_oe;
            invert_data ^= sig->invert_data;
        } 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_input = invert_input;
    sig->input_mask = input_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;
        }
        /* fallthrough */
    default:
        LOG_ERROR("unknown signal level '%s', use 0, 1 or z", CMD_ARGV[1]);
        return ERROR_COMMAND_ARGUMENT_INVALID;
    }
 
    return mpsse_flush(mpsse_ctx);
}
 
COMMAND_HANDLER(ftdi_handle_get_signal_command)
{
    if (CMD_ARGC < 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    struct signal *sig;
    uint16_t sig_data = 0;
    sig = find_signal_by_name(CMD_ARGV[0]);
    if (!sig) {
        command_print(CMD, "interface configuration doesn't define signal '%s'", CMD_ARGV[0]);
        return ERROR_FAIL;
    }
 
    int ret = ftdi_get_signal(sig, &sig_data);
    if (ret != ERROR_OK)
        return ret;
 
    command_print(CMD, "%#06x", sig_data);
 
    return ERROR_OK;
}
 
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 int 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;
}
 
COMMAND_HANDLER(ftdi_handle_tdo_sample_edge_command)
{
    const struct nvp *n;
    static const struct nvp nvp_ftdi_jtag_modes[] = {
        { .name = "rising", .value = JTAG_MODE },
        { .name = "falling", .value = JTAG_MODE_ALT },
        { .name = NULL, .value = -1 },
    };
 
    if (CMD_ARGC > 0) {
        n = nvp_name2value(nvp_ftdi_jtag_modes, CMD_ARGV[0]);
        if (!n->name)
            return ERROR_COMMAND_SYNTAX_ERROR;
        ftdi_jtag_mode = n->value;
 
    }
 
    n = nvp_value2name(nvp_ftdi_jtag_modes, ftdi_jtag_mode);
    command_print(CMD, "ftdi samples TDO on %s edge of TCK", n->name);
 
    return ERROR_OK;
}
 
#if BUILD_FTDI_CJTAG == 1
COMMAND_HANDLER(ftdi_handle_oscan1_mode_command)
{
    if (CMD_ARGC > 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    if (CMD_ARGC == 1)
        COMMAND_PARSE_ON_OFF(CMD_ARGV[0], oscan1_mode);
 
    command_print(CMD, "oscan1 mode: %s.", oscan1_mode ? "on" : "off");
    return ERROR_OK;
}
 
COMMAND_HANDLER(ftdi_handle_jscan3_mode_command)
{
    if (CMD_ARGC > 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    if (CMD_ARGC == 1)
        COMMAND_PARSE_ON_OFF(CMD_ARGV[0], jscan3_mode);
 
    command_print(CMD, "jscan3 mode: %s.", jscan3_mode ? "on" : "off");
    return ERROR_OK;
}
#endif
 
static const struct command_registration ftdi_subcommand_handlers[] = {
    {
        .name = "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 = "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 = "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 = "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] [-alias|-nalias name]",
    },
    {
        .name = "set_signal",
        .handler = &ftdi_handle_set_signal_command,
        .mode = COMMAND_EXEC,
        .help = "control a layout-specific signal",
        .usage = "name (1|0|z)",
    },
    {
        .name = "get_signal",
        .handler = &ftdi_handle_get_signal_command,
        .mode = COMMAND_EXEC,
        .help = "read the value of a layout-specific signal",
        .usage = "name",
    },
    {
        .name = "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)*",
    },
    {
        .name = "tdo_sample_edge",
        .handler = &ftdi_handle_tdo_sample_edge_command,
        .mode = COMMAND_ANY,
        .help = "set which TCK clock edge is used for sampling TDO "
            "- default is rising-edge (Setting to falling-edge may "
            "allow signalling speed increase)",
        .usage = "(rising|falling)",
    },
#if BUILD_FTDI_CJTAG == 1
    {
        .name = "oscan1_mode",
        .handler = &ftdi_handle_oscan1_mode_command,
        .mode = COMMAND_ANY,
        .help = "set to 'on' to use OScan1 mode for signaling, otherwise 'off' (default is 'off')",
        .usage = "(on|off)",
    },
    {
        .name = "jscan3_mode",
        .handler = &ftdi_handle_jscan3_mode_command,
        .mode = COMMAND_ANY,
        .help = "set to 'on' to use JScan3 mode for signaling, otherwise 'off' (default is 'off')",
        .usage = "(on|off)",
    },
#endif
    COMMAND_REGISTRATION_DONE
};
 
static const struct command_registration ftdi_command_handlers[] = {
    {
        .name = "ftdi",
        .mode = COMMAND_ANY,
        .help = "perform ftdi management",
        .chain = ftdi_subcommand_handlers,
        .usage = "",
    },
    COMMAND_REGISTRATION_DONE
};
 
static int create_default_signal(const char *name, uint16_t data_mask)
{
    struct signal *sig = create_signal(name);
    if (!sig) {
        LOG_ERROR("failed to create signal %s", name);
        return ERROR_FAIL;
    }
    sig->invert_data = false;
    sig->data_mask = data_mask;
    sig->invert_oe = false;
    sig->oe_mask = 0;
 
    return ERROR_OK;
}
 
static int create_signals(void)
{
    if (create_default_signal("TCK", 0x01) != ERROR_OK)
        return ERROR_FAIL;
    if (create_default_signal("TDI", 0x02) != ERROR_OK)
        return ERROR_FAIL;
    if (create_default_signal("TDO", 0x04) != ERROR_OK)
        return ERROR_FAIL;
    if (create_default_signal("TMS", 0x08) != ERROR_OK)
        return ERROR_FAIL;
    return ERROR_OK;
}
 
static int ftdi_swd_init(void)
{
    LOG_INFO("FTDI SWD mode enabled");
    swd_mode = true;
 
    if (create_signals() != ERROR_OK)
        return ERROR_FAIL;
 
    swd_cmd_queue_alloced = 10;
    swd_cmd_queue = malloc(swd_cmd_queue_alloced * sizeof(*swd_cmd_queue));
 
    return swd_cmd_queue ? ERROR_OK : ERROR_FAIL;
}
 
static void ftdi_swd_swdio_en(bool enable)
{
    struct signal *oe = find_signal_by_name("SWDIO_OE");
    if (oe) {
        if (oe->data_mask)
            ftdi_set_signal(oe, enable ? '1' : '0');
        else {
            /* Sets TDI/DO pin to input during rx when both pins are connected
               to SWDIO */
            if (enable)
                direction |= jtag_direction_init & 0x0002U;
            else
                direction &= ~0x0002U;
            mpsse_set_data_bits_low_byte(mpsse_ctx, output & 0xff, direction & 0xff);
        }
    }
}
 
static int ftdi_swd_run_queue(void)
{
    LOG_DEBUG_IO("Executing %zu queued transactions", swd_cmd_queue_length);
    int retval;
    struct signal *led = find_signal_by_name("LED");
 
    if (queued_retval != ERROR_OK) {
        LOG_DEBUG_IO("Skipping due to previous errors: %d", queued_retval);
        goto skip;
    }
 
    /* A transaction must be followed by another transaction or at least 8 idle cycles to
     * ensure that data is clocked through the AP. */
    mpsse_clock_data_out(mpsse_ctx, NULL, 0, 8, SWD_MODE);
 
    /* Terminate the "blink", if the current layout has that feature */
    if (led)
        ftdi_set_signal(led, '0');
 
    queued_retval = mpsse_flush(mpsse_ctx);
    if (queued_retval != ERROR_OK) {
        LOG_ERROR("MPSSE failed");
        goto skip;
    }
 
    for (size_t i = 0; i < swd_cmd_queue_length; i++) {
        int ack = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1, 3);
 
        /* Devices do not reply to DP_TARGETSEL write cmd, ignore received ack */
        bool check_ack = swd_cmd_returns_ack(swd_cmd_queue[i].cmd);
 
        LOG_CUSTOM_LEVEL((check_ack && ack != SWD_ACK_OK) ? LOG_LVL_DEBUG : LOG_LVL_DEBUG_IO,
                "%s%s %s %s reg %X = %08" PRIx32,
                check_ack ? "" : "ack ignored ",
                ack == SWD_ACK_OK ? "OK" : ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK",
                swd_cmd_queue[i].cmd & SWD_CMD_APNDP ? "AP" : "DP",
                swd_cmd_queue[i].cmd & SWD_CMD_RNW ? "read" : "write",
                (swd_cmd_queue[i].cmd & SWD_CMD_A32) >> 1,
                buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn,
                        1 + 3 + (swd_cmd_queue[i].cmd & SWD_CMD_RNW ? 0 : 1), 32));
 
        if (ack != SWD_ACK_OK && check_ack) {
            queued_retval = swd_ack_to_error_code(ack);
            goto skip;
 
        } else if (swd_cmd_queue[i].cmd & SWD_CMD_RNW) {
            uint32_t data = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3, 32);
            int parity = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 32, 1);
 
            if (parity != parity_u32(data)) {
                LOG_ERROR("SWD Read data parity mismatch");
                queued_retval = ERROR_FAIL;
                goto skip;
            }
 
            if (swd_cmd_queue[i].dst)
                *swd_cmd_queue[i].dst = data;
        }
    }
 
skip:
    swd_cmd_queue_length = 0;
    retval = queued_retval;
    queued_retval = ERROR_OK;
 
    /* Queue a new "blink" */
    if (led && retval == ERROR_OK)
        ftdi_set_signal(led, '1');
 
    return retval;
}
 
static void ftdi_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data, uint32_t ap_delay_clk)
{
    if (swd_cmd_queue_length >= swd_cmd_queue_alloced) {
        /* Not enough room in the queue. Run the queue and increase its size for next time.
         * Note that it's not possible to avoid running the queue here, because mpsse contains
         * pointers into the queue which may be invalid after the realloc. */
        queued_retval = ftdi_swd_run_queue();
        struct swd_cmd_queue_entry *q = realloc(swd_cmd_queue, swd_cmd_queue_alloced * 2 * sizeof(*swd_cmd_queue));
        if (q) {
            swd_cmd_queue = q;
            swd_cmd_queue_alloced *= 2;
            LOG_DEBUG("Increased SWD command queue to %zu elements", swd_cmd_queue_alloced);
        }
    }
 
    if (queued_retval != ERROR_OK)
        return;
 
    size_t i = swd_cmd_queue_length++;
    swd_cmd_queue[i].cmd = cmd | SWD_CMD_START | SWD_CMD_PARK;
 
    mpsse_clock_data_out(mpsse_ctx, &swd_cmd_queue[i].cmd, 0, 8, SWD_MODE);
 
    if (swd_cmd_queue[i].cmd & SWD_CMD_RNW) {
        /* Queue a read transaction */
        swd_cmd_queue[i].dst = dst;
 
        ftdi_swd_swdio_en(false);
        mpsse_clock_data_in(mpsse_ctx, swd_cmd_queue[i].trn_ack_data_parity_trn,
                0, 1 + 3 + 32 + 1 + 1, SWD_MODE);
        ftdi_swd_swdio_en(true);
    } else {
        /* Queue a write transaction */
        ftdi_swd_swdio_en(false);
 
        mpsse_clock_data_in(mpsse_ctx, swd_cmd_queue[i].trn_ack_data_parity_trn,
                0, 1 + 3 + 1, SWD_MODE);
 
        ftdi_swd_swdio_en(true);
 
        buf_set_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 1, 32, data);
        buf_set_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 1 + 32, 1, parity_u32(data));
 
        mpsse_clock_data_out(mpsse_ctx, swd_cmd_queue[i].trn_ack_data_parity_trn,
                1 + 3 + 1, 32 + 1, SWD_MODE);
    }
 
    /* Insert idle cycles after AP accesses to avoid WAIT */
    if (cmd & SWD_CMD_APNDP)
        mpsse_clock_data_out(mpsse_ctx, NULL, 0, ap_delay_clk, SWD_MODE);
 
}
 
static void ftdi_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay_clk)
{
    assert(cmd & SWD_CMD_RNW);
    ftdi_swd_queue_cmd(cmd, value, 0, ap_delay_clk);
}
 
static void ftdi_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk)
{
    assert(!(cmd & SWD_CMD_RNW));
    ftdi_swd_queue_cmd(cmd, NULL, value, ap_delay_clk);
}
 
static int ftdi_swd_switch_seq(enum swd_special_seq seq)
{
    switch (seq) {
    case LINE_RESET:
        LOG_DEBUG("SWD line reset");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_line_reset, 0, swd_seq_line_reset_len, SWD_MODE);
        break;
    case JTAG_TO_SWD:
        LOG_DEBUG("JTAG-to-SWD");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_jtag_to_swd, 0, swd_seq_jtag_to_swd_len, SWD_MODE);
        break;
    case JTAG_TO_DORMANT:
        LOG_DEBUG("JTAG-to-DORMANT");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_jtag_to_dormant, 0, swd_seq_jtag_to_dormant_len, SWD_MODE);
        break;
    case SWD_TO_JTAG:
        LOG_DEBUG("SWD-to-JTAG");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_swd_to_jtag, 0, swd_seq_swd_to_jtag_len, SWD_MODE);
        break;
    case SWD_TO_DORMANT:
        LOG_DEBUG("SWD-to-DORMANT");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_swd_to_dormant, 0, swd_seq_swd_to_dormant_len, SWD_MODE);
        break;
    case DORMANT_TO_SWD:
        LOG_DEBUG("DORMANT-to-SWD");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_dormant_to_swd, 0, swd_seq_dormant_to_swd_len, SWD_MODE);
        break;
    case DORMANT_TO_JTAG:
        LOG_DEBUG("DORMANT-to-JTAG");
        ftdi_swd_swdio_en(true);
        mpsse_clock_data_out(mpsse_ctx, swd_seq_dormant_to_jtag, 0, swd_seq_dormant_to_jtag_len, SWD_MODE);
        break;
    default:
        LOG_ERROR("Sequence %d not supported", seq);
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static const struct swd_driver ftdi_swd = {
    .init = ftdi_swd_init,
    .switch_seq = ftdi_swd_switch_seq,
    .read_reg = ftdi_swd_read_reg,
    .write_reg = ftdi_swd_write_reg,
    .run = ftdi_swd_run_queue,
};
 
static struct jtag_interface ftdi_interface = {
    .supported = DEBUG_CAP_TMS_SEQ,
    .execute_queue = ftdi_execute_queue,
};
 
struct adapter_driver ftdi_adapter_driver = {
    .name = "ftdi",
    .transport_ids = TRANSPORT_JTAG | TRANSPORT_SWD,
    .transport_preferred_id = TRANSPORT_JTAG,
    .commands = ftdi_command_handlers,
 
    .init = ftdi_initialize,
    .quit = ftdi_quit,
    .reset = ftdi_reset,
    .speed = ftdi_speed,
    .khz = ftdi_khz,
    .speed_div = ftdi_speed_div,
 
    .jtag_ops = &ftdi_interface,
    .swd_ops = &ftdi_swd,
};