kitprog.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2007 by Juergen Stuber <juergen@jstuber.net>            *
 *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   Copyright (C) 2011 by Jean-Christophe PLAGNIOL-VIILARD                *
 *   plagnioj@jcrosoft.com                                                 *
 *                                                                         *
 *   Copyright (C) 2015 by Marc Schink                                     *
 *   openocd-dev@marcschink.de                                             *
 *                                                                         *
 *   Copyright (C) 2015 by Paul Fertser                                    *
 *   fercerpav@gmail.com                                                   *
 *                                                                         *
 *   Copyright (C) 2015-2017 by Forest Crossman                            *
 *   cyrozap@gmail.com                                                     *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <stdint.h>
 
#include <hidapi.h>
 
#include <jtag/interface.h>
#include <jtag/swd.h>
#include <jtag/commands.h>
 
#include "libusb_helper.h"
 
#define VID 0x04b4
#define PID 0xf139
 
#define BULK_EP_IN  1
#define BULK_EP_OUT 2
 
#define CONTROL_TYPE_READ  0x01
#define CONTROL_TYPE_WRITE 0x02
 
#define CONTROL_COMMAND_PROGRAM 0x07
 
#define CONTROL_MODE_POLL_PROGRAMMER_STATUS  0x01
#define CONTROL_MODE_RESET_TARGET            0x04
#define CONTROL_MODE_SET_PROGRAMMER_PROTOCOL 0x40
#define CONTROL_MODE_SYNCHRONIZE_TRANSFER    0x41
#define CONTROL_MODE_ACQUIRE_SWD_TARGET      0x42
#define CONTROL_MODE_SEND_SWD_SEQUENCE       0x43
 
#define PROTOCOL_JTAG 0x00
#define PROTOCOL_SWD  0x01
 
#define DEVICE_PSOC4   0x00
#define DEVICE_PSOC3   0x01
#define DEVICE_UNKNOWN 0x02
#define DEVICE_PSOC5   0x03
 
#define ACQUIRE_MODE_RESET       0x00
#define ACQUIRE_MODE_POWER_CYCLE 0x01
 
#define SEQUENCE_LINE_RESET  0x00
#define SEQUENCE_JTAG_TO_SWD 0x01
 
#define PROGRAMMER_NOK_NACK 0x00
#define PROGRAMMER_OK_ACK   0x01
 
#define HID_TYPE_WRITE 0x00
#define HID_TYPE_READ  0x01
#define HID_TYPE_START 0x02
 
#define HID_COMMAND_POWER      0x80
#define HID_COMMAND_VERSION    0x81
#define HID_COMMAND_RESET      0x82
#define HID_COMMAND_CONFIGURE  0x8f
#define HID_COMMAND_BOOTLOADER 0xa0
 
/* 512 bytes seemed to work reliably.
 * It works with both full queue of mostly reads or mostly writes.
 *
 * Unfortunately the commit 88f429ead019fd6df96ec15f0d897385f3cef0d0
 * 5321: target/cortex_m: faster reading of all CPU registers
 * revealed a serious Kitprog firmware problem:
 * If the queue contains more than 63 transactions in the repeated pattern
 * one write, two reads, the firmware fails badly.
 * Sending 64 transactions makes the adapter to loose the connection with the
 * device. Sending 65 or more transactions causes the adapter to stop
 * receiving USB HID commands, next kitprog_hid_command() stops in hid_write().
 *
 * The problem was detected with KitProg v2.12 and v2.16.
 * We can guess the problem is something like a buffer or stack overflow.
 *
 * Use shorter buffer as a workaround. 300 bytes (= 60 transactions) works.
 */
#define SWD_MAX_BUFFER_LENGTH 300
 
struct kitprog {
    hid_device *hid_handle;
    struct libusb_device_handle *usb_handle;
    uint16_t packet_size;
    uint16_t packet_index;
    uint8_t *packet_buffer;
    char *serial;
    uint8_t hardware_version;
    uint8_t minor_version;
    uint8_t major_version;
    uint16_t millivolts;
 
    bool supports_jtag_to_swd;
};
 
struct pending_transfer_result {
    uint8_t cmd;
    uint32_t data;
    void *buffer;
};
 
static bool kitprog_init_acquire_psoc;
 
static int pending_transfer_count, pending_queue_len;
static struct pending_transfer_result *pending_transfers;
 
static int queued_retval;
 
static struct kitprog *kitprog_handle;
 
static int kitprog_usb_open(void);
static void kitprog_usb_close(void);
 
static int kitprog_hid_command(uint8_t *command, size_t command_length,
        uint8_t *data, size_t data_length);
static int kitprog_get_version(void);
static int kitprog_get_millivolts(void);
static int kitprog_get_info(void);
static int kitprog_set_protocol(uint8_t protocol);
static int kitprog_get_status(void);
static int kitprog_set_unknown(void);
static int kitprog_acquire_psoc(uint8_t psoc_type, uint8_t acquire_mode,
        uint8_t max_attempts);
static int kitprog_reset_target(void);
static int kitprog_swd_sync(void);
static int kitprog_swd_seq(uint8_t seq_type);
 
static int kitprog_generic_acquire(void);
 
static int kitprog_swd_run_queue(void);
static void kitprog_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data);
static int kitprog_swd_switch_seq(enum swd_special_seq seq);
 
 
static inline int mm_to_version(uint8_t major, uint8_t minor)
{
    return (major << 8) | minor;
}
 
static int kitprog_init(void)
{
    int retval;
 
    kitprog_handle = malloc(sizeof(struct kitprog));
    if (!kitprog_handle) {
        LOG_ERROR("Failed to allocate memory");
        return ERROR_FAIL;
    }
 
    if (kitprog_usb_open() != ERROR_OK) {
        LOG_ERROR("Can't find a KitProg device! Please check device connections and permissions.");
        return ERROR_JTAG_INIT_FAILED;
    }
 
    /* Get the current KitProg version and target voltage */
    if (kitprog_get_info() != ERROR_OK)
        return ERROR_FAIL;
 
    /* Compatibility check */
    kitprog_handle->supports_jtag_to_swd = true;
    int kitprog_version = mm_to_version(kitprog_handle->major_version, kitprog_handle->minor_version);
    if (kitprog_version < mm_to_version(2, 14)) {
        LOG_WARNING("KitProg firmware versions below v2.14 do not support sending JTAG to SWD sequences. These sequences will be substituted with SWD line resets.");
        kitprog_handle->supports_jtag_to_swd = false;
    }
 
    /* I have no idea what this does */
    if (kitprog_set_unknown() != ERROR_OK)
        return ERROR_FAIL;
 
    /* SWD won't work unless we do this */
    if (kitprog_swd_sync() != ERROR_OK)
        return ERROR_FAIL;
 
    /* Set the protocol to SWD */
    if (kitprog_set_protocol(PROTOCOL_SWD) != ERROR_OK)
        return ERROR_FAIL;
 
    /* Reset the SWD bus */
    if (kitprog_swd_seq(SEQUENCE_LINE_RESET) != ERROR_OK)
        return ERROR_FAIL;
 
    if (kitprog_init_acquire_psoc) {
        /* Try to acquire any device that will respond */
        retval = kitprog_generic_acquire();
        if (retval != ERROR_OK) {
            LOG_ERROR("No PSoC devices found");
            return retval;
        }
    }
 
    /* Allocate packet buffers and queues */
    kitprog_handle->packet_size = SWD_MAX_BUFFER_LENGTH;
    kitprog_handle->packet_buffer = malloc(SWD_MAX_BUFFER_LENGTH);
    if (!kitprog_handle->packet_buffer) {
        LOG_ERROR("Failed to allocate memory for the packet buffer");
        return ERROR_FAIL;
    }
 
    pending_queue_len = SWD_MAX_BUFFER_LENGTH / 5;
    pending_transfers = malloc(pending_queue_len * sizeof(*pending_transfers));
    if (!pending_transfers) {
        LOG_ERROR("Failed to allocate memory for the SWD transfer queue");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_quit(void)
{
    kitprog_usb_close();
 
    free(kitprog_handle->packet_buffer);
    free(kitprog_handle->serial);
    free(kitprog_handle);
    free(pending_transfers);
 
    return ERROR_OK;
}
 
/*************** kitprog usb functions *********************/
 
static int kitprog_get_usb_serial(void)
{
    int retval;
    const uint8_t str_index = 128; /* This seems to be a constant */
    char desc_string[256+1]; /* Max size of string descriptor */
 
    retval = libusb_get_string_descriptor_ascii(kitprog_handle->usb_handle,
            str_index, (unsigned char *)desc_string, sizeof(desc_string)-1);
    if (retval < 0) {
        LOG_ERROR("libusb_get_string_descriptor_ascii() failed with %d", retval);
        return ERROR_FAIL;
    }
 
    /* Null terminate descriptor string */
    desc_string[retval] = '\0';
 
    /* Allocate memory for the serial number */
    kitprog_handle->serial = calloc(retval + 1, sizeof(char));
    if (!kitprog_handle->serial) {
        LOG_ERROR("Failed to allocate memory for the serial number");
        return ERROR_FAIL;
    }
 
    /* Store the serial number */
    strncpy(kitprog_handle->serial, desc_string, retval + 1);
 
    return ERROR_OK;
}
 
static int kitprog_usb_open(void)
{
    const uint16_t vids[] = { VID, 0 };
    const uint16_t pids[] = { PID, 0 };
 
    if (jtag_libusb_open(vids, pids, &kitprog_handle->usb_handle, NULL) != ERROR_OK) {
        LOG_ERROR("Failed to open or find the device");
        return ERROR_FAIL;
    }
 
    /* Get the serial number for the device */
    if (kitprog_get_usb_serial() != ERROR_OK)
        LOG_WARNING("Failed to get KitProg serial number");
 
    /* Convert the ASCII serial number into a (wchar_t *) */
    size_t len = strlen(kitprog_handle->serial);
    wchar_t *hid_serial = calloc(len + 1, sizeof(wchar_t));
    if (!hid_serial) {
        LOG_ERROR("Failed to allocate memory for the serial number");
        return ERROR_FAIL;
    }
    if (mbstowcs(hid_serial, kitprog_handle->serial, len + 1) == (size_t)-1) {
        free(hid_serial);
        LOG_ERROR("Failed to convert serial number");
        return ERROR_FAIL;
    }
 
    /* Use HID for the KitBridge interface */
    kitprog_handle->hid_handle = hid_open(VID, PID, hid_serial);
    free(hid_serial);
    if (!kitprog_handle->hid_handle) {
        LOG_ERROR("Failed to open KitBridge (HID) interface");
        return ERROR_FAIL;
    }
 
    /* Claim the KitProg Programmer (bulk transfer) interface */
    if (libusb_claim_interface(kitprog_handle->usb_handle, 1) != ERROR_OK) {
        LOG_ERROR("Failed to claim KitProg Programmer (bulk transfer) interface");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static void kitprog_usb_close(void)
{
    if (kitprog_handle->hid_handle) {
        hid_close(kitprog_handle->hid_handle);
        hid_exit();
    }
 
    jtag_libusb_close(kitprog_handle->usb_handle);
}
 
/*************** kitprog lowlevel functions *********************/
 
static int kitprog_hid_command(uint8_t *command, size_t command_length,
        uint8_t *data, size_t data_length)
{
    int ret;
 
    ret = hid_write(kitprog_handle->hid_handle, command, command_length);
    if (ret < 0) {
        LOG_DEBUG("HID write returned %i", ret);
        return ERROR_FAIL;
    }
 
    ret = hid_read_timeout(kitprog_handle->hid_handle,
                            data, data_length, LIBUSB_TIMEOUT_MS);
    if (ret == 0) {
        LOG_ERROR("HID read timed out");
        return ERROR_TIMEOUT_REACHED;
    } else if (ret < 0) {
        LOG_ERROR("HID read error %ls", hid_error(kitprog_handle->hid_handle));
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_get_version(void)
{
    int ret;
 
    unsigned char command[3] = {HID_TYPE_START | HID_TYPE_WRITE, 0x00, HID_COMMAND_VERSION};
    unsigned char data[64];
 
    ret = kitprog_hid_command(command, sizeof(command), data, sizeof(data));
    if (ret != ERROR_OK)
        return ret;
 
    kitprog_handle->hardware_version = data[1];
    kitprog_handle->minor_version = data[2];
    kitprog_handle->major_version = data[3];
 
    return ERROR_OK;
}
 
static int kitprog_get_millivolts(void)
{
    int ret;
 
    unsigned char command[3] = {HID_TYPE_START | HID_TYPE_READ, 0x00, HID_COMMAND_POWER};
    unsigned char data[64];
 
    ret = kitprog_hid_command(command, sizeof(command), data, sizeof(data));
    if (ret != ERROR_OK)
        return ret;
 
    kitprog_handle->millivolts = (data[4] << 8) | data[3];
 
    return ERROR_OK;
}
 
static int kitprog_get_info(void)
{
    /* Get the device version information */
    if (kitprog_get_version() == ERROR_OK) {
        LOG_INFO("KitProg v%u.%02u",
            kitprog_handle->major_version, kitprog_handle->minor_version);
        LOG_INFO("Hardware version: %u",
            kitprog_handle->hardware_version);
    } else {
        LOG_ERROR("Failed to get KitProg version");
        return ERROR_FAIL;
    }
 
    /* Get the current reported target voltage */
    if (kitprog_get_millivolts() == ERROR_OK) {
        LOG_INFO("VTARG = %u.%03u V",
            kitprog_handle->millivolts / 1000, kitprog_handle->millivolts % 1000);
    } else {
        LOG_ERROR("Failed to get target voltage");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_set_protocol(uint8_t protocol)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (CONTROL_MODE_SET_PROGRAMMER_PROTOCOL << 8) | CONTROL_COMMAND_PROGRAM,
        protocol, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_get_status(void)
{
    int transferred = 0;
    char status = PROGRAMMER_NOK_NACK;
 
    /* Try a maximum of three times */
    for (int i = 0; (i < 3) && (transferred == 0); i++) {
        transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
            LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
            CONTROL_TYPE_READ,
            (CONTROL_MODE_POLL_PROGRAMMER_STATUS << 8) | CONTROL_COMMAND_PROGRAM,
            0, &status, 1, 0);
        jtag_sleep(1000);
    }
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_set_unknown(void)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (0x03 << 8) | 0x04,
        0, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_acquire_psoc(uint8_t psoc_type, uint8_t acquire_mode,
        uint8_t max_attempts)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (CONTROL_MODE_ACQUIRE_SWD_TARGET << 8) | CONTROL_COMMAND_PROGRAM,
        (max_attempts << 8) | (acquire_mode << 4) | psoc_type, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_reset_target(void)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (CONTROL_MODE_RESET_TARGET << 8) | CONTROL_COMMAND_PROGRAM,
        0, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_swd_sync(void)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (CONTROL_MODE_SYNCHRONIZE_TRANSFER << 8) | CONTROL_COMMAND_PROGRAM,
        0, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_swd_seq(uint8_t seq_type)
{
    int transferred;
    char status = PROGRAMMER_NOK_NACK;
 
    transferred = jtag_libusb_control_transfer(kitprog_handle->usb_handle,
        LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
        CONTROL_TYPE_WRITE,
        (CONTROL_MODE_SEND_SWD_SEQUENCE << 8) | CONTROL_COMMAND_PROGRAM,
        seq_type, &status, 1, 0);
 
    if (transferred == 0) {
        LOG_DEBUG("Zero bytes transferred");
        return ERROR_FAIL;
    }
 
    if (status != PROGRAMMER_OK_ACK) {
        LOG_DEBUG("Programmer did not respond OK");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_generic_acquire(void)
{
    const uint8_t devices[] = {DEVICE_PSOC4, DEVICE_PSOC3, DEVICE_PSOC5};
 
    int retval;
    int acquire_count = 0;
 
    /* Due to the way the SWD port is shared between the Test Controller (TC)
     * and the Cortex-M3 DAP on the PSoC 5LP, the TC is the default SWD target
     * after power is applied. To access the DAP, the PSoC 5LP requires at least
     * one acquisition sequence to be run (which switches the SWD mux from the
     * TC to the DAP). However, after the mux is switched, the Cortex-M3 will be
     * held in reset until a series of registers are written to (see section 5.2
     * of the PSoC 5LP Device Programming Specifications for details).
     *
     * Instead of writing the registers in this function, we just do what the
     * Cypress tools do and run the acquisition sequence a second time. This
     * will take the Cortex-M3 out of reset and enable debugging.
     */
    for (int i = 0; i < 2; i++) {
        for (uint8_t j = 0; j < sizeof(devices) && acquire_count == i; j++) {
            retval = kitprog_acquire_psoc(devices[j], ACQUIRE_MODE_RESET, 3);
            if (retval != ERROR_OK) {
                LOG_DEBUG("Acquisition function failed for device 0x%02x.", devices[j]);
                return retval;
            }
 
            if (kitprog_get_status() == ERROR_OK)
                acquire_count++;
        }
 
        jtag_sleep(10);
    }
 
    if (acquire_count < 2)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
/*************** swd wrapper functions *********************/
 
static int kitprog_swd_init(void)
{
    return ERROR_OK;
}
 
static void kitprog_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk)
{
    assert(!(cmd & SWD_CMD_RNW));
    kitprog_swd_queue_cmd(cmd, NULL, value);
}
 
static void kitprog_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay_clk)
{
    assert(cmd & SWD_CMD_RNW);
    kitprog_swd_queue_cmd(cmd, value, 0);
}
 
/*************** swd lowlevel functions ********************/
 
static int kitprog_swd_switch_seq(enum swd_special_seq seq)
{
    switch (seq) {
        case JTAG_TO_SWD:
            if (kitprog_handle->supports_jtag_to_swd) {
                LOG_DEBUG("JTAG to SWD");
                if (kitprog_swd_seq(SEQUENCE_JTAG_TO_SWD) != ERROR_OK)
                    return ERROR_FAIL;
                break;
            } else {
                LOG_DEBUG("JTAG to SWD not supported");
                /* Fall through to fix target reset issue */
            }
            /* fallthrough */
        case LINE_RESET:
            LOG_DEBUG("SWD line reset");
            if (kitprog_swd_seq(SEQUENCE_LINE_RESET) != ERROR_OK)
                return ERROR_FAIL;
            break;
        default:
            LOG_ERROR("Sequence %d not supported.", seq);
            return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int kitprog_swd_run_queue(void)
{
    int ret;
 
    size_t read_count = 0;
    size_t read_index = 0;
    size_t write_count = 0;
    uint8_t *buffer = kitprog_handle->packet_buffer;
 
    do {
        LOG_DEBUG_IO("Executing %d queued transactions", pending_transfer_count);
 
        if (queued_retval != ERROR_OK) {
            LOG_DEBUG("Skipping due to previous errors: %d", queued_retval);
            break;
        }
 
        if (!pending_transfer_count)
            break;
 
        for (int i = 0; i < pending_transfer_count; i++) {
            uint8_t cmd = pending_transfers[i].cmd;
            uint32_t data = pending_transfers[i].data;
 
            /* When proper WAIT handling is implemented in the
             * common SWD framework, this kludge can be
             * removed. However, this might lead to minor
             * performance degradation as the adapter wouldn't be
             * able to automatically retry anything (because ARM
             * has forgotten to implement sticky error flags
             * clearing). See also comments regarding
             * cmsis_dap_cmd_DAP_TFER_Configure() and
             * cmsis_dap_cmd_DAP_SWD_Configure() in
             * cmsis_dap_init().
             */
            if (!(cmd & SWD_CMD_RNW) &&
                !(cmd & SWD_CMD_APNDP) &&
                (cmd & SWD_CMD_A32) >> 1 == DP_CTRL_STAT &&
                (data & CORUNDETECT)) {
                LOG_DEBUG("refusing to enable sticky overrun detection");
                data &= ~CORUNDETECT;
            }
 
            LOG_DEBUG_IO("%s %s reg %x %"PRIx32,
                    cmd & SWD_CMD_APNDP ? "AP" : "DP",
                    cmd & SWD_CMD_RNW ? "read" : "write",
                  (cmd & SWD_CMD_A32) >> 1, data);
 
            buffer[write_count++] = (cmd | SWD_CMD_START | SWD_CMD_PARK) & ~SWD_CMD_STOP;
            read_count++;
            if (!(cmd & SWD_CMD_RNW)) {
                buffer[write_count++] = (data) & 0xff;
                buffer[write_count++] = (data >> 8) & 0xff;
                buffer[write_count++] = (data >> 16) & 0xff;
                buffer[write_count++] = (data >> 24) & 0xff;
            } else {
                read_count += 4;
            }
        }
 
        if (jtag_libusb_bulk_write(kitprog_handle->usb_handle,
                       BULK_EP_OUT, (char *)buffer,
                       write_count, 0, &ret)) {
            LOG_ERROR("Bulk write failed");
            queued_retval = ERROR_FAIL;
            break;
        } else {
            queued_retval = ERROR_OK;
        }
 
        /* KitProg firmware does not send a zero length packet
         * after the bulk-in transmission of a length divisible by bulk packet
         * size (64 bytes) as required by the USB specification.
         * Therefore libusb would wait for continuation of transmission.
         * Workaround: Limit bulk read size to expected number of bytes
         * for problematic transfer sizes. Otherwise use the maximum buffer
         * size here because the KitProg sometimes doesn't like bulk reads
         * of fewer than 62 bytes. (?!?!)
         */
        size_t read_count_workaround = SWD_MAX_BUFFER_LENGTH;
        if (read_count % 64 == 0)
            read_count_workaround = read_count;
 
        if (jtag_libusb_bulk_read(kitprog_handle->usb_handle,
                BULK_EP_IN | LIBUSB_ENDPOINT_IN, (char *)buffer,
                read_count_workaround, 1000, &ret)) {
            LOG_ERROR("Bulk read failed");
            queued_retval = ERROR_FAIL;
            break;
        } else {
            /* Handle garbage data by offsetting the initial read index */
            if ((unsigned int)ret > read_count)
                read_index = ret - read_count;
            queued_retval = ERROR_OK;
        }
 
        for (int i = 0; i < pending_transfer_count; i++) {
            if (pending_transfers[i].cmd & SWD_CMD_RNW) {
                uint32_t data = le_to_h_u32(&buffer[read_index]);
 
                LOG_DEBUG_IO("Read result: %"PRIx32, data);
 
                if (pending_transfers[i].buffer)
                    *(uint32_t *)pending_transfers[i].buffer = data;
 
                read_index += 4;
            }
 
            uint8_t ack = buffer[read_index] & 0x07;
            if (ack != SWD_ACK_OK || (buffer[read_index] & 0x08)) {
                LOG_DEBUG("SWD ack not OK: %d %s", i,
                      ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK");
                queued_retval = ack == SWD_ACK_WAIT ? ERROR_WAIT : ERROR_FAIL;
                break;
            }
            read_index++;
        }
    } while (0);
 
    pending_transfer_count = 0;
    int retval = queued_retval;
    queued_retval = ERROR_OK;
 
    return retval;
}
 
static void kitprog_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data)
{
    if (pending_transfer_count == pending_queue_len) {
        /* Not enough room in the queue. Run the queue. */
        queued_retval = kitprog_swd_run_queue();
    }
 
    if (queued_retval != ERROR_OK)
        return;
 
    pending_transfers[pending_transfer_count].data = data;
    pending_transfers[pending_transfer_count].cmd = cmd;
    if (cmd & SWD_CMD_RNW) {
        /* Queue a read transaction */
        pending_transfers[pending_transfer_count].buffer = dst;
    }
    pending_transfer_count++;
}
 
/*************** jtag lowlevel functions ********************/
 
static int kitprog_reset(int trst, int srst)
{
    int retval = ERROR_OK;
 
    if (trst == 1) {
        LOG_ERROR("KitProg: Interface has no TRST");
        return ERROR_FAIL;
    }
 
    if (srst == 1) {
        retval = kitprog_reset_target();
        /* Since the previous command also disables SWCLK output, we need to send an
         * SWD bus reset command to re-enable it. For some reason, running
         * kitprog_swd_seq() immediately after kitprog_reset_target() won't
         * actually fix this. Instead, kitprog_swd_seq() will be run once OpenOCD
         * tries to send a JTAG-to-SWD sequence, which should happen during
         * swd_check_reconnect (see the JTAG_TO_SWD case in kitprog_swd_switch_seq).
         */
    }
 
    if (retval != ERROR_OK)
        LOG_ERROR("KitProg: Interface reset failed");
    return retval;
}
 
COMMAND_HANDLER(kitprog_handle_info_command)
{
    int retval = kitprog_get_info();
 
    return retval;
}
 
 
COMMAND_HANDLER(kitprog_handle_acquire_psoc_command)
{
    int retval = kitprog_generic_acquire();
 
    return retval;
}
 
COMMAND_HANDLER(kitprog_handle_init_acquire_psoc_command)
{
    kitprog_init_acquire_psoc = true;
 
    return ERROR_OK;
}
 
static const struct command_registration kitprog_subcommand_handlers[] = {
    {
        .name = "info",
        .handler = &kitprog_handle_info_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "show KitProg info",
    },
    {
        .name = "acquire_psoc",
        .handler = &kitprog_handle_acquire_psoc_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "try to acquire a PSoC",
    },
    COMMAND_REGISTRATION_DONE
};
 
static const struct command_registration kitprog_command_handlers[] = {
    {
        .name = "kitprog",
        .mode = COMMAND_ANY,
        .help = "perform KitProg management",
        .usage = "<cmd>",
        .chain = kitprog_subcommand_handlers,
    },
    {
        .name = "kitprog_init_acquire_psoc",
        .handler = &kitprog_handle_init_acquire_psoc_command,
        .mode = COMMAND_CONFIG,
        .help = "try to acquire a PSoC during init",
        .usage = "",
    },
    COMMAND_REGISTRATION_DONE
};
 
static const struct swd_driver kitprog_swd = {
    .init = kitprog_swd_init,
    .switch_seq = kitprog_swd_switch_seq,
    .read_reg = kitprog_swd_read_reg,
    .write_reg = kitprog_swd_write_reg,
    .run = kitprog_swd_run_queue,
};
 
static const char * const kitprog_transports[] = { "swd", NULL };
 
struct adapter_driver kitprog_adapter_driver = {
    .name = "kitprog",
    .transports = kitprog_transports,
    .commands = kitprog_command_handlers,
 
    .init = kitprog_init,
    .quit = kitprog_quit,
    .reset = kitprog_reset,
 
    .swd_ops = &kitprog_swd,
};