ulink.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2011-2013 by Martin Schmoelzer                          *
 *   <martin.schmoelzer@student.tuwien.ac.at>                              *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <math.h>
#include "helper/system.h"
#include <jtag/interface.h>
#include <jtag/commands.h>
#include <target/image.h>
#include <libusb.h>
#include "libusb_helper.h"
#include "OpenULINK/include/msgtypes.h"
 
#define ULINK_VID                0xC251
 
#define ULINK_PID                0x2710
 
#define CPUCS_REG                0x7F92
 
#define REQUEST_FIRMWARE_LOAD    0xA0
 
#define CPU_RESET                0x01
 
#define CPU_START                0x00
 
#define FIRMWARE_ADDR            0x0000
 
#define USB_INTERFACE            0
 
#define ULINK_RENUMERATION_DELAY 1500000
 
#define ULINK_FIRMWARE_FILE      PKGDATADIR "/OpenULINK/ulink_firmware.hex"
 
#define SECTION_BUFFERSIZE       8192
 
#define SPLIT_SCAN_THRESHOLD     10
 
enum ulink_type {
    ULINK_1,
 
    ULINK_2,
 
    ULINK_PRO,
 
    ULINK_ME
};
 
enum ulink_payload_direction {
    PAYLOAD_DIRECTION_OUT,
    PAYLOAD_DIRECTION_IN
};
 
enum ulink_delay_type {
    DELAY_CLOCK_TCK,
    DELAY_CLOCK_TMS,
    DELAY_SCAN_IN,
    DELAY_SCAN_OUT,
    DELAY_SCAN_IO
};
 
struct ulink_cmd {
    uint8_t id;         
    uint8_t *payload_out;       
    uint8_t payload_out_size;   
    uint8_t *payload_in_start;  
    uint8_t *payload_in;        
    uint8_t payload_in_size;    
    bool needs_postprocessing;
 
    bool free_payload_in_start;
 
    struct jtag_command *cmd_origin;
 
    struct ulink_cmd *next;     
};
 
struct ulink {
    struct libusb_context *libusb_ctx;
    struct libusb_device_handle *usb_device_handle;
    enum ulink_type type;
 
    unsigned int ep_in;     
    unsigned int ep_out;        
    int delay_scan_in;  
    int delay_scan_out; 
    int delay_scan_io;  
    int delay_clock_tck;    
    int delay_clock_tms;    
    int commands_in_queue;      
    struct ulink_cmd *queue_start;  
    struct ulink_cmd *queue_end;    
};
 
/**************************** Function Prototypes *****************************/
 
/* USB helper functions */
static int ulink_usb_open(struct ulink **device);
static int ulink_usb_close(struct ulink **device);
 
/* ULINK MCU (Cypress EZ-USB) specific functions */
static int ulink_cpu_reset(struct ulink *device, unsigned char reset_bit);
static int ulink_load_firmware_and_renumerate(struct ulink **device, const char *filename,
        uint32_t delay);
static int ulink_load_firmware(struct ulink *device, const char *filename);
static int ulink_write_firmware_section(struct ulink *device,
        struct image *firmware_image, int section_index);
 
/* Generic helper functions */
static void ulink_print_signal_states(uint8_t input_signals, uint8_t output_signals);
 
/* OpenULINK command generation helper functions */
static int ulink_allocate_payload(struct ulink_cmd *ulink_cmd, int size,
        enum ulink_payload_direction direction);
 
/* OpenULINK command queue helper functions */
static int ulink_get_queue_size(struct ulink *device,
        enum ulink_payload_direction direction);
static void ulink_clear_queue(struct ulink *device);
static int ulink_append_queue(struct ulink *device, struct ulink_cmd *ulink_cmd);
static int ulink_execute_queued_commands(struct ulink *device, int timeout);
 
static void ulink_print_queue(struct ulink *device);
 
static int ulink_append_scan_cmd(struct ulink *device,
        enum scan_type scan_type,
        int scan_size_bits,
        uint8_t *tdi,
        uint8_t *tdo_start,
        uint8_t *tdo,
        uint8_t tms_count_start,
        uint8_t tms_sequence_start,
        uint8_t tms_count_end,
        uint8_t tms_sequence_end,
        struct jtag_command *origin,
        bool postprocess);
static int ulink_append_clock_tms_cmd(struct ulink *device, uint8_t count,
        uint8_t sequence);
static int ulink_append_clock_tck_cmd(struct ulink *device, uint16_t count);
static int ulink_append_get_signals_cmd(struct ulink *device);
static int ulink_append_set_signals_cmd(struct ulink *device, uint8_t low,
        uint8_t high);
static int ulink_append_sleep_cmd(struct ulink *device, uint32_t us);
static int ulink_append_configure_tck_cmd(struct ulink *device,
        int delay_scan_in,
        int delay_scan_out,
        int delay_scan_io,
        int delay_tck,
        int delay_tms);
static int __attribute__((unused)) ulink_append_led_cmd(struct ulink *device, uint8_t led_state);
static int ulink_append_test_cmd(struct ulink *device);
 
/* OpenULINK TCK frequency helper functions */
static int ulink_calculate_delay(enum ulink_delay_type type, long f, int *delay);
 
/* Interface between OpenULINK and OpenOCD */
static void ulink_set_end_state(enum tap_state endstate);
static int ulink_queue_statemove(struct ulink *device);
 
static int ulink_queue_scan(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_tlr_reset(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_runtest(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_reset(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_pathmove(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_sleep(struct ulink *device, struct jtag_command *cmd);
static int ulink_queue_stableclocks(struct ulink *device, struct jtag_command *cmd);
 
static int ulink_post_process_scan(struct ulink_cmd *ulink_cmd);
static int ulink_post_process_queue(struct ulink *device);
 
/* adapter driver functions */
static int ulink_execute_queue(struct jtag_command *cmd_queue);
static int ulink_khz(int khz, int *jtag_speed);
static int ulink_speed(int speed);
static int ulink_speed_div(int speed, int *khz);
static int ulink_init(void);
static int ulink_quit(void);
 
/****************************** Global Variables ******************************/
 
static struct ulink *ulink_handle;
 
/**************************** USB helper functions ****************************/
 
static int ulink_usb_open(struct ulink **device)
{
    ssize_t num_devices, i;
    bool found;
    struct libusb_device **usb_devices;
    struct libusb_device_descriptor usb_desc;
    struct libusb_device_handle *usb_device_handle;
 
    num_devices = libusb_get_device_list((*device)->libusb_ctx, &usb_devices);
 
    if (num_devices <= 0)
        return ERROR_FAIL;
 
    found = false;
    for (i = 0; i < num_devices; i++) {
        if (libusb_get_device_descriptor(usb_devices[i], &usb_desc) != 0)
            continue;
        else if (usb_desc.idVendor == ULINK_VID && usb_desc.idProduct == ULINK_PID) {
            found = true;
            break;
        }
    }
 
    if (!found)
        return ERROR_FAIL;
 
    if (libusb_open(usb_devices[i], &usb_device_handle) != 0)
        return ERROR_FAIL;
    libusb_free_device_list(usb_devices, 1);
 
    (*device)->usb_device_handle = usb_device_handle;
    (*device)->type = ULINK_1;
 
    return ERROR_OK;
}
 
static int ulink_usb_close(struct ulink **device)
{
    if (libusb_release_interface((*device)->usb_device_handle, 0) != 0)
        return ERROR_FAIL;
 
    libusb_close((*device)->usb_device_handle);
 
    (*device)->usb_device_handle = NULL;
 
    return ERROR_OK;
}
 
/******************* ULINK CPU (EZ-USB) specific functions ********************/
 
static int ulink_cpu_reset(struct ulink *device, unsigned char reset_bit)
{
    int ret;
 
    ret = libusb_control_transfer(device->usb_device_handle,
            (LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE),
            REQUEST_FIRMWARE_LOAD, CPUCS_REG, 0, &reset_bit, 1, LIBUSB_TIMEOUT_MS);
 
    /* usb_control_msg() returns the number of bytes transferred during the
     * DATA stage of the control transfer - must be exactly 1 in this case! */
    if (ret != 1)
        return ERROR_FAIL;
    return ERROR_OK;
}
 
static int ulink_load_firmware_and_renumerate(struct ulink **device,
    const char *filename, uint32_t delay)
{
    int ret;
 
    /* Basic process: After downloading the firmware, the ULINK will disconnect
     * itself and re-connect after a short amount of time so we have to close
     * the handle and re-enumerate USB devices */
 
    ret = ulink_load_firmware(*device, filename);
    if (ret != ERROR_OK)
        return ret;
 
    ret = ulink_usb_close(device);
    if (ret != ERROR_OK)
        return ret;
 
    usleep(delay);
 
    ret = ulink_usb_open(device);
    if (ret != ERROR_OK)
        return ret;
 
    return ERROR_OK;
}
 
static int ulink_load_firmware(struct ulink *device, const char *filename)
{
    struct image ulink_firmware_image;
    int ret;
 
    ret = ulink_cpu_reset(device, CPU_RESET);
    if (ret != ERROR_OK) {
        LOG_ERROR("Could not halt ULINK CPU");
        return ret;
    }
 
    ulink_firmware_image.base_address = 0;
    ulink_firmware_image.base_address_set = false;
 
    ret = image_open(&ulink_firmware_image, filename, "ihex");
    if (ret != ERROR_OK) {
        LOG_ERROR("Could not load firmware image");
        return ret;
    }
 
    /* Download all sections in the image to ULINK */
    for (unsigned int i = 0; i < ulink_firmware_image.num_sections; i++) {
        ret = ulink_write_firmware_section(device, &ulink_firmware_image, i);
        if (ret != ERROR_OK)
            return ret;
    }
 
    image_close(&ulink_firmware_image);
 
    ret = ulink_cpu_reset(device, CPU_START);
    if (ret != ERROR_OK) {
        LOG_ERROR("Could not restart ULINK CPU");
        return ret;
    }
 
    return ERROR_OK;
}
 
static int ulink_write_firmware_section(struct ulink *device,
    struct image *firmware_image, int section_index)
{
    uint16_t addr, size, bytes_remaining, chunk_size;
    uint8_t data[SECTION_BUFFERSIZE];
    uint8_t *data_ptr = data;
    size_t size_read;
    int ret;
 
    size = (uint16_t)firmware_image->sections[section_index].size;
    addr = (uint16_t)firmware_image->sections[section_index].base_address;
 
    LOG_DEBUG("section %02i at addr 0x%04x (size 0x%04x)", section_index, addr,
        size);
 
    /* Copy section contents to local buffer */
    ret = image_read_section(firmware_image, section_index, 0, size, data,
            &size_read);
 
    if ((ret != ERROR_OK) || (size_read != size)) {
        /* Propagating the return code would return '0' (misleadingly indicating
         * successful execution of the function) if only the size check fails. */
        return ERROR_FAIL;
    }
 
    bytes_remaining = size;
 
    /* Send section data in chunks of up to 64 bytes to ULINK */
    while (bytes_remaining > 0) {
        if (bytes_remaining > 64)
            chunk_size = 64;
        else
            chunk_size = bytes_remaining;
 
        ret = libusb_control_transfer(device->usb_device_handle,
                (LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE),
                REQUEST_FIRMWARE_LOAD, addr, FIRMWARE_ADDR, (unsigned char *)data_ptr,
                chunk_size, LIBUSB_TIMEOUT_MS);
 
        if (ret != (int)chunk_size) {
            /* Abort if libusb sent less data than requested */
            return ERROR_FAIL;
        }
 
        bytes_remaining -= chunk_size;
        addr += chunk_size;
        data_ptr += chunk_size;
    }
 
    return ERROR_OK;
}
 
/************************** Generic helper functions **************************/
 
static void ulink_print_signal_states(uint8_t input_signals, uint8_t output_signals)
{
    LOG_INFO("ULINK signal states: TDI: %i, TDO: %i, TMS: %i, TCK: %i, TRST: %i,"
        " SRST: %i",
        (output_signals & SIGNAL_TDI   ? 1 : 0),
        (input_signals  & SIGNAL_TDO   ? 1 : 0),
        (output_signals & SIGNAL_TMS   ? 1 : 0),
        (output_signals & SIGNAL_TCK   ? 1 : 0),
        (output_signals & SIGNAL_TRST  ? 0 : 1),    /* Inverted by hardware */
        (output_signals & SIGNAL_RESET ? 0 : 1));   /* Inverted by hardware */
}
 
/**************** OpenULINK command generation helper functions ***************/
 
static int ulink_allocate_payload(struct ulink_cmd *ulink_cmd, int size,
    enum ulink_payload_direction direction)
{
    uint8_t *payload;
 
    payload = calloc(size, sizeof(uint8_t));
 
    if (!payload) {
        LOG_ERROR("Could not allocate OpenULINK command payload: out of memory");
        return ERROR_FAIL;
    }
 
    switch (direction) {
    case PAYLOAD_DIRECTION_OUT:
        if (ulink_cmd->payload_out) {
            LOG_ERROR("BUG: Duplicate payload allocation for OpenULINK command");
            free(payload);
            return ERROR_FAIL;
        }
        ulink_cmd->payload_out = payload;
        ulink_cmd->payload_out_size = size;
        break;
    case PAYLOAD_DIRECTION_IN:
        if (ulink_cmd->payload_in_start) {
            LOG_ERROR("BUG: Duplicate payload allocation for OpenULINK command");
            free(payload);
            return ERROR_FAIL;
        }
        ulink_cmd->payload_in_start = payload;
        ulink_cmd->payload_in = payload;
        ulink_cmd->payload_in_size = size;
 
        /* By default, free payload_in_start in ulink_clear_queue(). Commands
         * that do not want this behavior (e.g. split scans) must turn it off
         * separately! */
        ulink_cmd->free_payload_in_start = true;
        break;
    }
 
    return ERROR_OK;
}
 
/****************** OpenULINK command queue helper functions ******************/
 
static int ulink_get_queue_size(struct ulink *device,
    enum ulink_payload_direction direction)
{
    struct ulink_cmd *current = device->queue_start;
    int sum = 0;
 
    while (current) {
        switch (direction) {
        case PAYLOAD_DIRECTION_OUT:
            sum += current->payload_out_size + 1;   /* + 1 byte for Command ID */
            break;
        case PAYLOAD_DIRECTION_IN:
            sum += current->payload_in_size;
            break;
        }
 
        current = current->next;
    }
 
    return sum;
}
 
static void ulink_clear_queue(struct ulink *device)
{
    struct ulink_cmd *current = device->queue_start;
    struct ulink_cmd *next = NULL;
 
    while (current) {
        /* Save pointer to next element */
        next = current->next;
 
        /* Free payloads: OUT payload can be freed immediately */
        free(current->payload_out);
        current->payload_out = NULL;
 
        /* IN payload MUST be freed ONLY if no other commands use the
         * payload_in_start buffer */
        if (current->free_payload_in_start) {
            free(current->payload_in_start);
            current->payload_in_start = NULL;
            current->payload_in = NULL;
        }
 
        /* Free queue element */
        free(current);
 
        /* Proceed with next element */
        current = next;
    }
 
    device->commands_in_queue = 0;
    device->queue_start = NULL;
    device->queue_end = NULL;
}
 
static int ulink_append_queue(struct ulink *device, struct ulink_cmd *ulink_cmd)
{
    int newsize_out, newsize_in;
    int ret = ERROR_OK;
 
    newsize_out = ulink_get_queue_size(device, PAYLOAD_DIRECTION_OUT) + 1
        + ulink_cmd->payload_out_size;
 
    newsize_in = ulink_get_queue_size(device, PAYLOAD_DIRECTION_IN)
        + ulink_cmd->payload_in_size;
 
    /* Check if the current command can be appended to the queue */
    if ((newsize_out > 64) || (newsize_in > 64)) {
        /* New command does not fit. Execute all commands in queue before starting
         * new queue with the current command as first entry. */
        ret = ulink_execute_queued_commands(device, LIBUSB_TIMEOUT_MS);
 
        if (ret == ERROR_OK)
            ret = ulink_post_process_queue(device);
 
        if (ret == ERROR_OK)
            ulink_clear_queue(device);
    }
 
    if (!device->queue_start) {
        /* Queue was empty */
        device->commands_in_queue = 1;
 
        device->queue_start = ulink_cmd;
        device->queue_end = ulink_cmd;
    } else {
        /* There are already commands in the queue */
        device->commands_in_queue++;
 
        device->queue_end->next = ulink_cmd;
        device->queue_end = ulink_cmd;
    }
 
    if (ret != ERROR_OK)
        ulink_clear_queue(device);
 
    return ret;
}
 
static int ulink_execute_queued_commands(struct ulink *device, int timeout)
{
    struct ulink_cmd *current;
    int ret, i, index_out, index_in, count_out, count_in, transferred;
    uint8_t buffer[64];
 
    if (LOG_LEVEL_IS(LOG_LVL_DEBUG_IO))
        ulink_print_queue(device);
 
    index_out = 0;
    count_out = 0;
    count_in = 0;
 
    for (current = device->queue_start; current; current = current->next) {
        /* Add command to packet */
        buffer[index_out] = current->id;
        index_out++;
        count_out++;
 
        for (i = 0; i < current->payload_out_size; i++)
            buffer[index_out + i] = current->payload_out[i];
        index_out += current->payload_out_size;
        count_in += current->payload_in_size;
        count_out += current->payload_out_size;
    }
 
    /* Send packet to ULINK */
    ret = libusb_bulk_transfer(device->usb_device_handle, device->ep_out,
            (unsigned char *)buffer, count_out, &transferred, timeout);
    if (ret != 0)
        return ERROR_FAIL;
    if (transferred != count_out)
        return ERROR_FAIL;
 
    /* Wait for response if commands contain IN payload data */
    if (count_in > 0) {
        ret = libusb_bulk_transfer(device->usb_device_handle, device->ep_in,
                (unsigned char *)buffer, 64, &transferred, timeout);
        if (ret != 0)
            return ERROR_FAIL;
        if (transferred != count_in)
            return ERROR_FAIL;
 
        /* Write back IN payload data */
        index_in = 0;
        for (current = device->queue_start; current; current = current->next) {
            for (i = 0; i < current->payload_in_size; i++) {
                current->payload_in[i] = buffer[index_in];
                index_in++;
            }
        }
    }
 
    return ERROR_OK;
}
 
static const char *ulink_cmd_id_string(uint8_t id)
{
    switch (id) {
    case CMD_SCAN_IN:
        return "CMD_SCAN_IN";
    case CMD_SLOW_SCAN_IN:
        return "CMD_SLOW_SCAN_IN";
    case CMD_SCAN_OUT:
        return "CMD_SCAN_OUT";
    case CMD_SLOW_SCAN_OUT:
        return "CMD_SLOW_SCAN_OUT";
    case CMD_SCAN_IO:
        return "CMD_SCAN_IO";
    case CMD_SLOW_SCAN_IO:
        return "CMD_SLOW_SCAN_IO";
    case CMD_CLOCK_TMS:
        return "CMD_CLOCK_TMS";
    case CMD_SLOW_CLOCK_TMS:
        return "CMD_SLOW_CLOCK_TMS";
    case CMD_CLOCK_TCK:
        return "CMD_CLOCK_TCK";
    case CMD_SLOW_CLOCK_TCK:
        return "CMD_SLOW_CLOCK_TCK";
    case CMD_SLEEP_US:
        return "CMD_SLEEP_US";
    case CMD_SLEEP_MS:
        return "CMD_SLEEP_MS";
    case CMD_GET_SIGNALS:
        return "CMD_GET_SIGNALS";
    case CMD_SET_SIGNALS:
        return "CMD_SET_SIGNALS";
    case CMD_CONFIGURE_TCK_FREQ:
        return "CMD_CONFIGURE_TCK_FREQ";
    case CMD_SET_LEDS:
        return "CMD_SET_LEDS";
    case CMD_TEST:
        return "CMD_TEST";
    default:
        return "CMD_UNKNOWN";
    }
}
 
static void ulink_print_command(struct ulink_cmd *ulink_cmd)
{
    int i;
 
    printf("  %-22s | OUT size = %i, bytes = 0x",
        ulink_cmd_id_string(ulink_cmd->id), ulink_cmd->payload_out_size);
 
    for (i = 0; i < ulink_cmd->payload_out_size; i++)
        printf("%02X ", ulink_cmd->payload_out[i]);
    printf("\n                         | IN size  = %i\n",
        ulink_cmd->payload_in_size);
}
 
static void ulink_print_queue(struct ulink *device)
{
    struct ulink_cmd *current;
 
    printf("OpenULINK command queue:\n");
 
    for (current = device->queue_start; current; current = current->next)
        ulink_print_command(current);
}
 
static int ulink_append_scan_cmd(struct ulink *device, enum scan_type scan_type,
    int scan_size_bits, uint8_t *tdi, uint8_t *tdo_start, uint8_t *tdo,
    uint8_t tms_count_start, uint8_t tms_sequence_start, uint8_t tms_count_end,
    uint8_t tms_sequence_end, struct jtag_command *origin, bool postprocess)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret, i, scan_size_bytes;
    uint8_t bits_last_byte;
 
    if (!cmd)
        return ERROR_FAIL;
 
    /* Check size of command. USB buffer can hold 64 bytes, 1 byte is command ID,
     * 5 bytes are setup data -> 58 remaining payload bytes for TDI data */
    if (scan_size_bits > (58 * 8)) {
        LOG_ERROR("BUG: Tried to create CMD_SCAN_IO OpenULINK command with too"
            " large payload");
        free(cmd);
        return ERROR_FAIL;
    }
 
    scan_size_bytes = DIV_ROUND_UP(scan_size_bits, 8);
 
    bits_last_byte = scan_size_bits % 8;
    if (bits_last_byte == 0)
        bits_last_byte = 8;
 
    /* Allocate out_payload depending on scan type */
    switch (scan_type) {
    case SCAN_IN:
        if (device->delay_scan_in < 0)
            cmd->id = CMD_SCAN_IN;
        else
            cmd->id = CMD_SLOW_SCAN_IN;
        ret = ulink_allocate_payload(cmd, 5, PAYLOAD_DIRECTION_OUT);
        break;
    case SCAN_OUT:
        if (device->delay_scan_out < 0)
            cmd->id = CMD_SCAN_OUT;
        else
            cmd->id = CMD_SLOW_SCAN_OUT;
        ret = ulink_allocate_payload(cmd, scan_size_bytes + 5, PAYLOAD_DIRECTION_OUT);
        break;
    case SCAN_IO:
        if (device->delay_scan_io < 0)
            cmd->id = CMD_SCAN_IO;
        else
            cmd->id = CMD_SLOW_SCAN_IO;
        ret = ulink_allocate_payload(cmd, scan_size_bytes + 5, PAYLOAD_DIRECTION_OUT);
        break;
    default:
        LOG_ERROR("BUG: %s() encountered an unknown scan type", __func__);
        ret = ERROR_FAIL;
        break;
    }
 
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    /* Build payload_out that is common to all scan types */
    cmd->payload_out[0] = scan_size_bytes & 0xFF;
    cmd->payload_out[1] = bits_last_byte & 0xFF;
    cmd->payload_out[2] = ((tms_count_start & 0x0F) << 4) | (tms_count_end & 0x0F);
    cmd->payload_out[3] = tms_sequence_start;
    cmd->payload_out[4] = tms_sequence_end;
 
    /* Setup payload_out for types with OUT transfer */
    if ((scan_type == SCAN_OUT) || (scan_type == SCAN_IO)) {
        for (i = 0; i < scan_size_bytes; i++)
            cmd->payload_out[i + 5] = tdi[i];
    }
 
    /* Setup payload_in pointers for types with IN transfer */
    if ((scan_type == SCAN_IN) || (scan_type == SCAN_IO)) {
        cmd->payload_in_start = tdo_start;
        cmd->payload_in = tdo;
        cmd->payload_in_size = scan_size_bytes;
    }
 
    cmd->needs_postprocessing = postprocess;
    cmd->cmd_origin = origin;
 
    /* For scan commands, we free payload_in_start only when the command is
     * the last in a series of split commands or a stand-alone command */
    cmd->free_payload_in_start = postprocess;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_clock_tms_cmd(struct ulink *device, uint8_t count,
    uint8_t sequence)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    if (device->delay_clock_tms < 0)
        cmd->id = CMD_CLOCK_TMS;
    else
        cmd->id = CMD_SLOW_CLOCK_TMS;
 
    /* CMD_CLOCK_TMS has two OUT payload bytes and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 2, PAYLOAD_DIRECTION_OUT);
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = count;
    cmd->payload_out[1] = sequence;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_clock_tck_cmd(struct ulink *device, uint16_t count)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    if (device->delay_clock_tck < 0)
        cmd->id = CMD_CLOCK_TCK;
    else
        cmd->id = CMD_SLOW_CLOCK_TCK;
 
    /* CMD_CLOCK_TCK has two OUT payload bytes and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 2, PAYLOAD_DIRECTION_OUT);
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = count & 0xff;
    cmd->payload_out[1] = (count >> 8) & 0xff;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_get_signals_cmd(struct ulink *device)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_GET_SIGNALS;
    cmd->needs_postprocessing = true;
 
    /* CMD_GET_SIGNALS has two IN payload bytes */
    ret = ulink_allocate_payload(cmd, 2, PAYLOAD_DIRECTION_IN);
 
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_set_signals_cmd(struct ulink *device, uint8_t low,
    uint8_t high)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_SET_SIGNALS;
 
    /* CMD_SET_SIGNALS has two OUT payload bytes and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 2, PAYLOAD_DIRECTION_OUT);
 
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = low;
    cmd->payload_out[1] = high;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_sleep_cmd(struct ulink *device, uint32_t us)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_SLEEP_US;
 
    /* CMD_SLEEP_US has two OUT payload bytes and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 2, PAYLOAD_DIRECTION_OUT);
 
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = us & 0x00ff;
    cmd->payload_out[1] = (us >> 8) & 0x00ff;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_configure_tck_cmd(struct ulink *device, int delay_scan_in,
    int delay_scan_out, int delay_scan_io, int delay_tck, int delay_tms)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_CONFIGURE_TCK_FREQ;
 
    /* CMD_CONFIGURE_TCK_FREQ has five OUT payload bytes and zero
     * IN payload bytes */
    ret = ulink_allocate_payload(cmd, 5, PAYLOAD_DIRECTION_OUT);
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    if (delay_scan_in < 0)
        cmd->payload_out[0] = 0;
    else
        cmd->payload_out[0] = (uint8_t)delay_scan_in;
 
    if (delay_scan_out < 0)
        cmd->payload_out[1] = 0;
    else
        cmd->payload_out[1] = (uint8_t)delay_scan_out;
 
    if (delay_scan_io < 0)
        cmd->payload_out[2] = 0;
    else
        cmd->payload_out[2] = (uint8_t)delay_scan_io;
 
    if (delay_tck < 0)
        cmd->payload_out[3] = 0;
    else
        cmd->payload_out[3] = (uint8_t)delay_tck;
 
    if (delay_tms < 0)
        cmd->payload_out[4] = 0;
    else
        cmd->payload_out[4] = (uint8_t)delay_tms;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_led_cmd(struct ulink *device, uint8_t led_state)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_SET_LEDS;
 
    /* CMD_SET_LEDS has one OUT payload byte and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 1, PAYLOAD_DIRECTION_OUT);
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = led_state;
 
    return ulink_append_queue(device, cmd);
}
 
static int ulink_append_test_cmd(struct ulink *device)
{
    struct ulink_cmd *cmd = calloc(1, sizeof(struct ulink_cmd));
    int ret;
 
    if (!cmd)
        return ERROR_FAIL;
 
    cmd->id = CMD_TEST;
 
    /* CMD_TEST has one OUT payload byte and zero IN payload bytes */
    ret = ulink_allocate_payload(cmd, 1, PAYLOAD_DIRECTION_OUT);
    if (ret != ERROR_OK) {
        free(cmd);
        return ret;
    }
 
    cmd->payload_out[0] = 0xAA;
 
    return ulink_append_queue(device, cmd);
}
 
/****************** OpenULINK TCK frequency helper functions ******************/
 
static int ulink_calculate_delay(enum ulink_delay_type type, long f, int *delay)
{
    float t, x, x_ceil;
 
    /* Calculate period of requested TCK frequency */
    t = 1.0 / (float)(f);
 
    switch (type) {
    case DELAY_CLOCK_TCK:
        x = (t - (float)(6E-6)) / (float)(4E-6);
        break;
    case DELAY_CLOCK_TMS:
        x = (t - (float)(8.5E-6)) / (float)(4E-6);
        break;
    case DELAY_SCAN_IN:
        x = (t - (float)(8.8308E-6)) / (float)(4E-6);
        break;
    case DELAY_SCAN_OUT:
        x = (t - (float)(1.0527E-5)) / (float)(4E-6);
        break;
    case DELAY_SCAN_IO:
        x = (t - (float)(1.3132E-5)) / (float)(4E-6);
        break;
    default:
        return ERROR_FAIL;
        break;
    }
 
    /* Check if the delay value is negative. This happens when a frequency is
     * requested that is too high for the delay loop implementation. In this
     * case, set delay value to zero. */
    if (x < 0)
        x = 0;
 
    /* We need to convert the exact delay value to an integer. Therefore, we
     * round the exact value UP to ensure that the resulting frequency is NOT
     * higher than the requested frequency. */
    x_ceil = ceilf(x);
 
    /* Check if the value is within limits */
    if (x_ceil > 255)
        return ERROR_FAIL;
 
    *delay = (int)x_ceil;
 
    return ERROR_OK;
}
 
static long ulink_calculate_frequency(enum ulink_delay_type type, int delay)
{
    float t, f_float;
 
    if (delay > 255)
        return 0;
 
    switch (type) {
    case DELAY_CLOCK_TCK:
        if (delay < 0)
            t = (float)(2.666E-6);
        else
            t = (float)(4E-6) * (float)(delay) + (float)(6E-6);
        break;
    case DELAY_CLOCK_TMS:
        if (delay < 0)
            t = (float)(5.666E-6);
        else
            t = (float)(4E-6) * (float)(delay) + (float)(8.5E-6);
        break;
    case DELAY_SCAN_IN:
        if (delay < 0)
            t = (float)(5.5E-6);
        else
            t = (float)(4E-6) * (float)(delay) + (float)(8.8308E-6);
        break;
    case DELAY_SCAN_OUT:
        if (delay < 0)
            t = (float)(7.0E-6);
        else
            t = (float)(4E-6) * (float)(delay) + (float)(1.0527E-5);
        break;
    case DELAY_SCAN_IO:
        if (delay < 0)
            t = (float)(9.926E-6);
        else
            t = (float)(4E-6) * (float)(delay) + (float)(1.3132E-5);
        break;
    default:
        return 0;
    }
 
    f_float = 1.0 / t;
    return roundf(f_float);
}
 
/******************* Interface between OpenULINK and OpenOCD ******************/
 
static void ulink_set_end_state(enum tap_state endstate)
{
    if (tap_is_state_stable(endstate))
        tap_set_end_state(endstate);
    else {
        LOG_ERROR("BUG: %s is not a valid end state", tap_state_name(endstate));
        exit(EXIT_FAILURE);
    }
}
 
static int ulink_queue_statemove(struct ulink *device)
{
    uint8_t tms_sequence, tms_count;
    int ret;
 
    if (tap_get_state() == tap_get_end_state()) {
        /* Do nothing if we are already there */
        return ERROR_OK;
    }
 
    tms_sequence = tap_get_tms_path(tap_get_state(), tap_get_end_state());
    tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 
    ret = ulink_append_clock_tms_cmd(device, tms_count, tms_sequence);
 
    if (ret == ERROR_OK)
        tap_set_state(tap_get_end_state());
 
    return ret;
}
 
static int ulink_queue_scan(struct ulink *device, struct jtag_command *cmd)
{
    uint32_t scan_size_bits, scan_size_bytes, bits_last_scan;
    uint32_t scans_max_payload, bytecount;
    uint8_t *tdi_buffer_start = NULL, *tdi_buffer = NULL;
    uint8_t *tdo_buffer_start = NULL, *tdo_buffer = NULL;
 
    uint8_t first_tms_count, first_tms_sequence;
    uint8_t last_tms_count, last_tms_sequence;
 
    uint8_t tms_count_pause, tms_sequence_pause;
    uint8_t tms_count_resume, tms_sequence_resume;
 
    uint8_t tms_count_start, tms_sequence_start;
    uint8_t tms_count_end, tms_sequence_end;
 
    enum scan_type type;
    int ret;
 
    /* Determine scan size */
    scan_size_bits = jtag_scan_size(cmd->cmd.scan);
    scan_size_bytes = DIV_ROUND_UP(scan_size_bits, 8);
 
    /* Determine scan type (IN/OUT/IO) */
    type = jtag_scan_type(cmd->cmd.scan);
 
    /* Determine number of scan commands with maximum payload */
    scans_max_payload = scan_size_bytes / 58;
 
    /* Determine size of last shift command */
    bits_last_scan = scan_size_bits - (scans_max_payload * 58 * 8);
 
    /* Allocate TDO buffer if required */
    if ((type == SCAN_IN) || (type == SCAN_IO)) {
        tdo_buffer_start = calloc(scan_size_bytes, sizeof(uint8_t));
 
        if (!tdo_buffer_start)
            return ERROR_FAIL;
 
        tdo_buffer = tdo_buffer_start;
    }
 
    /* Fill TDI buffer if required */
    if ((type == SCAN_OUT) || (type == SCAN_IO)) {
        jtag_build_buffer(cmd->cmd.scan, &tdi_buffer_start);
        tdi_buffer = tdi_buffer_start;
    }
 
    /* Get TAP state transitions */
    if (cmd->cmd.scan->ir_scan) {
        ulink_set_end_state(TAP_IRSHIFT);
        first_tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
        first_tms_sequence = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 
        tap_set_state(TAP_IRSHIFT);
        tap_set_end_state(cmd->cmd.scan->end_state);
        last_tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
        last_tms_sequence = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 
        /* TAP state transitions for split scans */
        tms_count_pause = tap_get_tms_path_len(TAP_IRSHIFT, TAP_IRPAUSE);
        tms_sequence_pause = tap_get_tms_path(TAP_IRSHIFT, TAP_IRPAUSE);
        tms_count_resume = tap_get_tms_path_len(TAP_IRPAUSE, TAP_IRSHIFT);
        tms_sequence_resume = tap_get_tms_path(TAP_IRPAUSE, TAP_IRSHIFT);
    } else {
        ulink_set_end_state(TAP_DRSHIFT);
        first_tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
        first_tms_sequence = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 
        tap_set_state(TAP_DRSHIFT);
        tap_set_end_state(cmd->cmd.scan->end_state);
        last_tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
        last_tms_sequence = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 
        /* TAP state transitions for split scans */
        tms_count_pause = tap_get_tms_path_len(TAP_DRSHIFT, TAP_DRPAUSE);
        tms_sequence_pause = tap_get_tms_path(TAP_DRSHIFT, TAP_DRPAUSE);
        tms_count_resume = tap_get_tms_path_len(TAP_DRPAUSE, TAP_DRSHIFT);
        tms_sequence_resume = tap_get_tms_path(TAP_DRPAUSE, TAP_DRSHIFT);
    }
 
    /* Generate scan commands */
    bytecount = scan_size_bytes;
    while (bytecount > 0) {
        if (bytecount == scan_size_bytes) {
            /* This is the first scan */
            tms_count_start = first_tms_count;
            tms_sequence_start = first_tms_sequence;
        } else {
            /* Resume from previous scan */
            tms_count_start = tms_count_resume;
            tms_sequence_start = tms_sequence_resume;
        }
 
        if (bytecount > 58) {   /* Full scan, at least one scan will follow */
            tms_count_end = tms_count_pause;
            tms_sequence_end = tms_sequence_pause;
 
            ret = ulink_append_scan_cmd(device,
                    type,
                    58 * 8,
                    tdi_buffer,
                    tdo_buffer_start,
                    tdo_buffer,
                    tms_count_start,
                    tms_sequence_start,
                    tms_count_end,
                    tms_sequence_end,
                    cmd,
                    false);
 
            bytecount -= 58;
 
            /* Update TDI and TDO buffer pointers */
            if (tdi_buffer_start)
                tdi_buffer += 58;
            if (tdo_buffer_start)
                tdo_buffer += 58;
        } else if (bytecount == 58) {   /* Full scan, no further scans */
            tms_count_end = last_tms_count;
            tms_sequence_end = last_tms_sequence;
 
            ret = ulink_append_scan_cmd(device,
                    type,
                    58 * 8,
                    tdi_buffer,
                    tdo_buffer_start,
                    tdo_buffer,
                    tms_count_start,
                    tms_sequence_start,
                    tms_count_end,
                    tms_sequence_end,
                    cmd,
                    true);
 
            bytecount = 0;
        } else {/* Scan with less than maximum payload, no further scans */
            tms_count_end = last_tms_count;
            tms_sequence_end = last_tms_sequence;
 
            ret = ulink_append_scan_cmd(device,
                    type,
                    bits_last_scan,
                    tdi_buffer,
                    tdo_buffer_start,
                    tdo_buffer,
                    tms_count_start,
                    tms_sequence_start,
                    tms_count_end,
                    tms_sequence_end,
                    cmd,
                    true);
 
            bytecount = 0;
        }
 
        if (ret != ERROR_OK) {
            free(tdi_buffer_start);
            free(tdo_buffer_start);
            return ret;
        }
    }
 
    free(tdi_buffer_start);
 
    /* Set current state to the end state requested by the command */
    tap_set_state(cmd->cmd.scan->end_state);
 
    return ERROR_OK;
}
 
static int ulink_queue_tlr_reset(struct ulink *device, struct jtag_command *cmd)
{
    int ret;
 
    ret = ulink_append_clock_tms_cmd(device, 5, 0xff);
 
    if (ret == ERROR_OK)
        tap_set_state(TAP_RESET);
 
    return ret;
}
 
static int ulink_queue_runtest(struct ulink *device, struct jtag_command *cmd)
{
    int ret;
 
    /* Only perform statemove if the TAP currently isn't in the TAP_IDLE state */
    if (tap_get_state() != TAP_IDLE) {
        ulink_set_end_state(TAP_IDLE);
        ulink_queue_statemove(device);
    }
 
    /* Generate the clock cycles */
    ret = ulink_append_clock_tck_cmd(device, cmd->cmd.runtest->num_cycles);
    if (ret != ERROR_OK)
        return ret;
 
    /* Move to end state specified in command */
    if (cmd->cmd.runtest->end_state != tap_get_state()) {
        tap_set_end_state(cmd->cmd.runtest->end_state);
        ulink_queue_statemove(device);
    }
 
    return ERROR_OK;
}
 
static int ulink_queue_reset(struct ulink *device, struct jtag_command *cmd)
{
    uint8_t low = 0, high = 0;
 
    if (cmd->cmd.reset->trst) {
        tap_set_state(TAP_RESET);
        high |= SIGNAL_TRST;
    } else
        low |= SIGNAL_TRST;
 
    if (cmd->cmd.reset->srst)
        high |= SIGNAL_RESET;
    else
        low |= SIGNAL_RESET;
 
    return ulink_append_set_signals_cmd(device, low, high);
}
 
static int ulink_queue_pathmove(struct ulink *device, struct jtag_command *cmd)
{
    int ret, state_count;
    enum tap_state *path;
    uint8_t tms_sequence;
 
    unsigned int num_states = cmd->cmd.pathmove->num_states;
    path = cmd->cmd.pathmove->path;
    state_count = 0;
 
    while (num_states > 0) {
        unsigned int batch_size;
 
        tms_sequence = 0;
 
        /* Determine batch size */
        if (num_states >= 8)
            batch_size = 8;
        else
            batch_size = num_states;
 
        for (unsigned int i = 0; i < batch_size; i++) {
            if (tap_state_transition(tap_get_state(), false) == path[state_count]) {
                /* Append '0' transition: clear bit 'i' in tms_sequence */
                buf_set_u32(&tms_sequence, i, 1, 0x0);
            } else if (tap_state_transition(tap_get_state(), true)
                   == path[state_count]) {
                /* Append '1' transition: set bit 'i' in tms_sequence */
                buf_set_u32(&tms_sequence, i, 1, 0x1);
            } else {
                /* Invalid state transition */
                LOG_ERROR("BUG: %s -> %s isn't a valid TAP state transition",
                    tap_state_name(tap_get_state()),
                    tap_state_name(path[state_count]));
                return ERROR_FAIL;
            }
 
            tap_set_state(path[state_count]);
            state_count++;
            num_states--;
        }
 
        /* Append CLOCK_TMS command to OpenULINK command queue */
        LOG_INFO(
            "pathmove batch: count = %i, sequence = 0x%x", batch_size, tms_sequence);
        ret = ulink_append_clock_tms_cmd(ulink_handle, batch_size, tms_sequence);
        if (ret != ERROR_OK)
            return ret;
    }
 
    return ERROR_OK;
}
 
static int ulink_queue_sleep(struct ulink *device, struct jtag_command *cmd)
{
    /* IMPORTANT! Due to the time offset in command execution introduced by
     * command queueing, this needs to be implemented in the ULINK device */
    return ulink_append_sleep_cmd(device, cmd->cmd.sleep->us);
}
 
static int ulink_queue_stableclocks(struct ulink *device, struct jtag_command *cmd)
{
    int ret;
 
    if (!tap_is_state_stable(tap_get_state())) {
        LOG_ERROR("JTAG_STABLECLOCKS: state not stable");
        return ERROR_FAIL;
    }
 
    unsigned int num_cycles = cmd->cmd.stableclocks->num_cycles;
 
    /* TMS stays either high (Test Logic Reset state) or low (all other states) */
    if (tap_get_state() == TAP_RESET)
        ret = ulink_append_set_signals_cmd(device, 0, SIGNAL_TMS);
    else
        ret = ulink_append_set_signals_cmd(device, SIGNAL_TMS, 0);
 
    if (ret != ERROR_OK)
        return ret;
 
    while (num_cycles > 0) {
        if (num_cycles > 0xFFFF) {
            /* OpenULINK CMD_CLOCK_TCK can generate up to 0xFFFF (uint16_t) cycles */
            ret = ulink_append_clock_tck_cmd(device, 0xFFFF);
            num_cycles -= 0xFFFF;
        } else {
            ret = ulink_append_clock_tck_cmd(device, num_cycles);
            num_cycles = 0;
        }
 
        if (ret != ERROR_OK)
            return ret;
    }
 
    return ERROR_OK;
}
 
static int ulink_post_process_scan(struct ulink_cmd *ulink_cmd)
{
    struct jtag_command *cmd = ulink_cmd->cmd_origin;
    int ret;
 
    switch (jtag_scan_type(cmd->cmd.scan)) {
    case SCAN_IN:
    case SCAN_IO:
        ret = jtag_read_buffer(ulink_cmd->payload_in_start, cmd->cmd.scan);
        break;
    case SCAN_OUT:
        /* Nothing to do for OUT scans */
        ret = ERROR_OK;
        break;
    default:
        LOG_ERROR("BUG: %s() encountered an unknown JTAG scan type", __func__);
        ret = ERROR_FAIL;
        break;
    }
 
    return ret;
}
 
static int ulink_post_process_queue(struct ulink *device)
{
    struct ulink_cmd *current;
    struct jtag_command *openocd_cmd;
    int ret;
 
    current = device->queue_start;
 
    while (current) {
        openocd_cmd = current->cmd_origin;
 
        /* Check if a corresponding OpenOCD command is stored for this
         * OpenULINK command */
        if (current->needs_postprocessing && openocd_cmd) {
            switch (openocd_cmd->type) {
            case JTAG_SCAN:
                ret = ulink_post_process_scan(current);
                break;
            case JTAG_TLR_RESET:
            case JTAG_RUNTEST:
            case JTAG_RESET:
            case JTAG_PATHMOVE:
            case JTAG_SLEEP:
            case JTAG_STABLECLOCKS:
                /* Nothing to do for these commands */
                ret = ERROR_OK;
                break;
            default:
                ret = ERROR_FAIL;
                LOG_ERROR("BUG: %s() encountered unknown JTAG command type", __func__);
                break;
            }
 
            if (ret != ERROR_OK)
                return ret;
        }
 
        current = current->next;
    }
 
    return ERROR_OK;
}
 
/**************************** JTAG driver functions ***************************/
 
static int ulink_execute_queue(struct jtag_command *cmd_queue)
{
    struct jtag_command *cmd = cmd_queue;
    int ret;
 
    while (cmd) {
        switch (cmd->type) {
        case JTAG_SCAN:
            ret = ulink_queue_scan(ulink_handle, cmd);
            break;
        case JTAG_TLR_RESET:
            ret = ulink_queue_tlr_reset(ulink_handle, cmd);
            break;
        case JTAG_RUNTEST:
            ret = ulink_queue_runtest(ulink_handle, cmd);
            break;
        case JTAG_RESET:
            ret = ulink_queue_reset(ulink_handle, cmd);
            break;
        case JTAG_PATHMOVE:
            ret = ulink_queue_pathmove(ulink_handle, cmd);
            break;
        case JTAG_SLEEP:
            ret = ulink_queue_sleep(ulink_handle, cmd);
            break;
        case JTAG_STABLECLOCKS:
            ret = ulink_queue_stableclocks(ulink_handle, cmd);
            break;
        default:
            ret = ERROR_FAIL;
            LOG_ERROR("BUG: encountered unknown JTAG command type");
            break;
        }
 
        if (ret != ERROR_OK)
            return ret;
 
        cmd = cmd->next;
    }
 
    if (ulink_handle->commands_in_queue > 0) {
        ret = ulink_execute_queued_commands(ulink_handle, LIBUSB_TIMEOUT_MS);
        if (ret != ERROR_OK)
            return ret;
 
        ret = ulink_post_process_queue(ulink_handle);
        if (ret != ERROR_OK)
            return ret;
 
        ulink_clear_queue(ulink_handle);
    }
 
    return ERROR_OK;
}
 
static int ulink_khz(int khz, int *jtag_speed)
{
    int ret;
 
    if (khz == 0) {
        LOG_ERROR("RCLK not supported");
        return ERROR_FAIL;
    }
 
    /* CLOCK_TCK commands are decoupled from others. Therefore, the frequency
     * setting can be done independently from all other commands. */
    if (khz >= 375)
        ulink_handle->delay_clock_tck = -1;
    else {
        ret = ulink_calculate_delay(DELAY_CLOCK_TCK, khz * 1000,
                &ulink_handle->delay_clock_tck);
        if (ret != ERROR_OK)
            return ret;
    }
 
    /* SCAN_{IN,OUT,IO} commands invoke CLOCK_TMS commands. Therefore, if the
     * requested frequency goes below the maximum frequency for SLOW_CLOCK_TMS
     * commands, all SCAN commands MUST also use the variable frequency
     * implementation! */
    if (khz >= 176) {
        ulink_handle->delay_clock_tms = -1;
        ulink_handle->delay_scan_in = -1;
        ulink_handle->delay_scan_out = -1;
        ulink_handle->delay_scan_io = -1;
    } else {
        ret = ulink_calculate_delay(DELAY_CLOCK_TMS, khz * 1000,
                &ulink_handle->delay_clock_tms);
        if (ret != ERROR_OK)
            return ret;
 
        ret = ulink_calculate_delay(DELAY_SCAN_IN, khz * 1000,
                &ulink_handle->delay_scan_in);
        if (ret != ERROR_OK)
            return ret;
 
        ret = ulink_calculate_delay(DELAY_SCAN_OUT, khz * 1000,
                &ulink_handle->delay_scan_out);
        if (ret != ERROR_OK)
            return ret;
 
        ret = ulink_calculate_delay(DELAY_SCAN_IO, khz * 1000,
                &ulink_handle->delay_scan_io);
        if (ret != ERROR_OK)
            return ret;
    }
 
    LOG_DEBUG_IO("ULINK TCK setup: delay_tck      = %i (%li Hz),",
        ulink_handle->delay_clock_tck,
        ulink_calculate_frequency(DELAY_CLOCK_TCK, ulink_handle->delay_clock_tck));
    LOG_DEBUG_IO("                 delay_tms      = %i (%li Hz),",
        ulink_handle->delay_clock_tms,
        ulink_calculate_frequency(DELAY_CLOCK_TMS, ulink_handle->delay_clock_tms));
    LOG_DEBUG_IO("                 delay_scan_in  = %i (%li Hz),",
        ulink_handle->delay_scan_in,
        ulink_calculate_frequency(DELAY_SCAN_IN, ulink_handle->delay_scan_in));
    LOG_DEBUG_IO("                 delay_scan_out = %i (%li Hz),",
        ulink_handle->delay_scan_out,
        ulink_calculate_frequency(DELAY_SCAN_OUT, ulink_handle->delay_scan_out));
    LOG_DEBUG_IO("                 delay_scan_io  = %i (%li Hz),",
        ulink_handle->delay_scan_io,
        ulink_calculate_frequency(DELAY_SCAN_IO, ulink_handle->delay_scan_io));
 
    /* Configure the ULINK device with the new delay values */
    ret = ulink_append_configure_tck_cmd(ulink_handle,
            ulink_handle->delay_scan_in,
            ulink_handle->delay_scan_out,
            ulink_handle->delay_scan_io,
            ulink_handle->delay_clock_tck,
            ulink_handle->delay_clock_tms);
 
    if (ret != ERROR_OK)
        return ret;
 
    *jtag_speed = khz;
 
    return ERROR_OK;
}
 
static int ulink_speed(int speed)
{
    int dummy;
 
    return ulink_khz(speed, &dummy);
}
 
static int ulink_speed_div(int speed, int *khz)
{
    *khz = speed;
 
    return ERROR_OK;
}
 
static int ulink_init(void)
{
    int ret, transferred;
    char str_manufacturer[20];
    bool download_firmware = false;
    unsigned char *dummy;
    uint8_t input_signals, output_signals;
 
    ulink_handle = calloc(1, sizeof(struct ulink));
    if (!ulink_handle)
        return ERROR_FAIL;
 
    libusb_init(&ulink_handle->libusb_ctx);
 
    ret = ulink_usb_open(&ulink_handle);
    if (ret != ERROR_OK) {
        LOG_ERROR("Could not open ULINK device");
        free(ulink_handle);
        ulink_handle = NULL;
        return ret;
    }
 
    /* Get String Descriptor to determine if firmware needs to be loaded */
    ret = libusb_get_string_descriptor_ascii(ulink_handle->usb_device_handle, 1, (unsigned char *)str_manufacturer, 20);
    if (ret < 0) {
        /* Could not get descriptor -> Unconfigured or original Keil firmware */
        download_firmware = true;
    } else {
        /* We got a String Descriptor, check if it is the correct one */
        if (strncmp(str_manufacturer, "OpenULINK", 9) != 0)
            download_firmware = true;
    }
 
    if (download_firmware) {
        LOG_INFO("Loading OpenULINK firmware. This is reversible by power-cycling"
            " ULINK device.");
        ret = ulink_load_firmware_and_renumerate(&ulink_handle,
                ULINK_FIRMWARE_FILE, ULINK_RENUMERATION_DELAY);
        if (ret != ERROR_OK) {
            LOG_ERROR("Could not download firmware and re-numerate ULINK");
            free(ulink_handle);
            ulink_handle = NULL;
            return ret;
        }
    } else
        LOG_INFO("ULINK device is already running OpenULINK firmware");
 
    /* Get OpenULINK USB IN/OUT endpoints and claim the interface */
    ret = jtag_libusb_choose_interface(ulink_handle->usb_device_handle,
        &ulink_handle->ep_in, &ulink_handle->ep_out, -1, -1, -1, -1);
    if (ret != ERROR_OK)
        return ret;
 
    /* Initialize OpenULINK command queue */
    ulink_clear_queue(ulink_handle);
 
    /* Issue one test command with short timeout */
    ret = ulink_append_test_cmd(ulink_handle);
    if (ret != ERROR_OK)
        return ret;
 
    ret = ulink_execute_queued_commands(ulink_handle, 200);
    if (ret != ERROR_OK) {
        /* Sending test command failed. The ULINK device may be forever waiting for
         * the host to fetch an USB Bulk IN packet (e. g. OpenOCD crashed or was
         * shut down by the user via Ctrl-C. Try to retrieve this Bulk IN packet. */
        dummy = calloc(64, sizeof(uint8_t));
 
        ret = libusb_bulk_transfer(ulink_handle->usb_device_handle, ulink_handle->ep_in,
                dummy, 64, &transferred, 200);
 
        free(dummy);
 
        if (ret != 0 || transferred == 0) {
            /* Bulk IN transfer failed -> unrecoverable error condition */
            LOG_ERROR("Cannot communicate with ULINK device. Disconnect ULINK from "
                "the USB port and re-connect, then re-run OpenOCD");
            free(ulink_handle);
            ulink_handle = NULL;
            return ERROR_FAIL;
        }
#ifdef _DEBUG_USB_COMMS_
        else {
            /* Successfully received Bulk IN packet -> continue */
            LOG_INFO("Recovered from lost Bulk IN packet");
        }
#endif
    }
    ulink_clear_queue(ulink_handle);
 
    ret = ulink_append_get_signals_cmd(ulink_handle);
    if (ret == ERROR_OK)
        ret = ulink_execute_queued_commands(ulink_handle, 200);
 
    if (ret == ERROR_OK) {
        /* Post-process the single CMD_GET_SIGNALS command */
        input_signals = ulink_handle->queue_start->payload_in[0];
        output_signals = ulink_handle->queue_start->payload_in[1];
 
        ulink_print_signal_states(input_signals, output_signals);
    }
 
    ulink_clear_queue(ulink_handle);
 
    return ERROR_OK;
}
 
static int ulink_quit(void)
{
    int ret;
 
    ret = ulink_usb_close(&ulink_handle);
    free(ulink_handle);
 
    return ret;
}
 
COMMAND_HANDLER(ulink_download_firmware_handler)
{
    int ret;
 
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
 
    LOG_INFO("Downloading ULINK firmware image %s", CMD_ARGV[0]);
 
    /* Download firmware image in CMD_ARGV[0] */
    ret = ulink_load_firmware_and_renumerate(&ulink_handle, CMD_ARGV[0],
            ULINK_RENUMERATION_DELAY);
 
    return ret;
}
 
/*************************** Command Registration **************************/
 
static const struct command_registration ulink_subcommand_handlers[] = {
    {
        .name = "download_firmware",
        .handler = &ulink_download_firmware_handler,
        .mode = COMMAND_EXEC,
        .help = "download firmware image to ULINK device",
        .usage = "path/to/ulink_firmware.hex",
    },
    COMMAND_REGISTRATION_DONE,
};
 
static const struct command_registration ulink_command_handlers[] = {
    {
        .name = "ulink",
        .mode = COMMAND_ANY,
        .help = "perform ulink management",
        .chain = ulink_subcommand_handlers,
        .usage = "",
    },
    COMMAND_REGISTRATION_DONE
};
 
static struct jtag_interface ulink_interface = {
    .execute_queue = ulink_execute_queue,
};
 
struct adapter_driver ulink_adapter_driver = {
    .name = "ulink",
    .transport_ids = TRANSPORT_JTAG,
    .transport_preferred_id = TRANSPORT_JTAG,
    .commands = ulink_command_handlers,
 
    .init = ulink_init,
    .quit = ulink_quit,
    .speed = ulink_speed,
    .khz = ulink_khz,
    .speed_div = ulink_speed_div,
 
    .jtag_ops = &ulink_interface,
};