nulink_usb.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2016-2017 by Nuvoton                                    *
 *   Zale Yu <cyyu@nuvoton.com>                                            *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
/* project specific includes */
#include <helper/binarybuffer.h>
#include <jtag/adapter.h>
#include <jtag/interface.h>
#include <jtag/hla/hla_layout.h>
#include <jtag/hla/hla_transport.h>
#include <jtag/hla/hla_interface.h>
#include <target/target.h>
 
#include <target/cortex_m.h>
 
#include <hidapi.h>
 
#include "libusb_helper.h"
 
#define NULINK_READ_TIMEOUT  LIBUSB_TIMEOUT_MS
 
#define NULINK_HID_MAX_SIZE   (64)
#define NULINK2_HID_MAX_SIZE   (1024)
#define V6M_MAX_COMMAND_LENGTH (NULINK_HID_MAX_SIZE - 2)
#define V7M_MAX_COMMAND_LENGTH (NULINK_HID_MAX_SIZE - 3)
 
#define NULINK2_USB_PID1  (0x5200)
#define NULINK2_USB_PID2  (0x5201)
 
struct nulink_usb_handle {
    hid_device *dev_handle;
    uint16_t max_packet_size;
    uint8_t usbcmdidx;
    uint8_t cmdidx;
    uint8_t cmdsize;
    uint8_t cmdbuf[NULINK2_HID_MAX_SIZE + 1];
    uint8_t tempbuf[NULINK2_HID_MAX_SIZE];
    uint8_t databuf[NULINK2_HID_MAX_SIZE];
    uint32_t max_mem_packet;
    uint16_t hardware_config; /* bit 0: 1:Nu-Link-Pro, 0:Nu-Link */
 
    int (*xfer)(void *handle, uint8_t *buf, int size);
    void (*init_buffer)(void *handle, uint32_t size);
};
 
/* ICE Command */
#define CMD_READ_REG                0xB5UL
#define CMD_READ_RAM                0xB1UL
#define CMD_WRITE_REG               0xB8UL
#define CMD_WRITE_RAM               0xB9UL
#define CMD_CHECK_ID                0xA3UL
#define CMD_MCU_RESET               0xE2UL
#define CMD_CHECK_MCU_STOP          0xD8UL
#define CMD_MCU_STEP_RUN            0xD1UL
#define CMD_MCU_STOP_RUN            0xD2UL
#define CMD_MCU_FREE_RUN            0xD3UL
#define CMD_SET_CONFIG              0xA2UL
 
#define ARM_SRAM_BASE               0x20000000UL
 
#define HARDWARE_CONFIG_NULINKPRO   1
#define HARDWARE_CONFIG_NULINK2     2
 
enum nulink_reset {
    RESET_AUTO = 0,
    RESET_HW = 1,
    RESET_SYSRESETREQ = 2,
    RESET_VECTRESET = 3,
    RESET_FAST_RESCUE = 4, /* Rescue and erase the chip, need very fast speed */
};
 
enum nulink_connect {
    CONNECT_NORMAL = 0,      /* Support all reset method */
    CONNECT_PRE_RESET = 1,   /* Support all reset method */
    CONNECT_UNDER_RESET = 2, /* Support all reset method */
    CONNECT_NONE = 3,        /* Support RESET_HW, (RESET_AUTO = RESET_HW) */
    CONNECT_DISCONNECT = 4,  /* Support RESET_NONE, (RESET_AUTO = RESET_NONE) */
    CONNECT_ICP_MODE = 5     /* Support NUC505 ICP mode*/
};
 
static int nulink_usb_xfer_rw(void *handle, uint8_t *buf)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    int ret = hid_write(h->dev_handle, h->cmdbuf, h->max_packet_size + 1);
    if (ret < 0) {
        LOG_ERROR("hid_write");
        return ERROR_FAIL;
    }
 
    ret = hid_read_timeout(h->dev_handle, buf, h->max_packet_size, NULINK_READ_TIMEOUT);
    if (ret < 0) {
        LOG_ERROR("hid_read_timeout");
        return ERROR_FAIL;
    }
    return ERROR_OK;
}
 
static int nulink1_usb_xfer(void *handle, uint8_t *buf, int size)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    int err = nulink_usb_xfer_rw(h, h->tempbuf);
 
    memcpy(buf, h->tempbuf + 2, V6M_MAX_COMMAND_LENGTH);
 
    return err;
}
 
static int nulink2_usb_xfer(void *handle, uint8_t *buf, int size)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    int err = nulink_usb_xfer_rw(h, h->tempbuf);
 
    memcpy(buf, h->tempbuf + 3, V7M_MAX_COMMAND_LENGTH);
 
    return err;
}
 
static void nulink1_usb_init_buffer(void *handle, uint32_t size)
{
    struct nulink_usb_handle *h = handle;
 
    h->cmdidx = 0;
 
    memset(h->cmdbuf, 0, h->max_packet_size + 1);
    memset(h->tempbuf, 0, h->max_packet_size);
    memset(h->databuf, 0, h->max_packet_size);
 
    h->cmdbuf[0] = 0; /* report number */
    h->cmdbuf[1] = ++h->usbcmdidx & 0x7F;
    h->cmdbuf[2] = size;
    h->cmdidx += 3;
}
 
static void nulink2_usb_init_buffer(void *handle, uint32_t size)
{
    struct nulink_usb_handle *h = handle;
 
    h->cmdidx = 0;
 
    memset(h->cmdbuf, 0, h->max_packet_size + 1);
    memset(h->tempbuf, 0, h->max_packet_size);
    memset(h->databuf, 0, h->max_packet_size);
 
    h->cmdbuf[0] = 0; /* report number */
    h->cmdbuf[1] = ++h->usbcmdidx & 0x7F;
    h_u16_to_le(h->cmdbuf + 2, size);
    h->cmdidx += 4;
}
 
static inline int nulink_usb_xfer(void *handle, uint8_t *buf, int size)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    return h->xfer(handle, buf, size);
}
 
static inline void nulink_usb_init_buffer(void *handle, uint32_t size)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    h->init_buffer(handle, size);
}
 
static int nulink_usb_version(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_version");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, V6M_MAX_COMMAND_LENGTH);
 
    memset(h->cmdbuf + h->cmdidx, 0xFF, V6M_MAX_COMMAND_LENGTH);
    h->cmdbuf[h->cmdidx + 4] = 0xA1; /* host_rev_num: 6561 */;
    h->cmdbuf[h->cmdidx + 5] = 0x19;
 
    int res = nulink_usb_xfer(handle, h->databuf, h->cmdsize);
    if (res != ERROR_OK)
        return res;
 
    LOG_INFO("Nu-Link firmware_version %" PRIu32 ", product_id (0x%08" PRIx32 ")",
             le_to_h_u32(h->databuf),
             le_to_h_u32(h->databuf + 4 * 1));
 
    const bool is_nulinkpro = !!(le_to_h_u32(h->databuf + 4 * 2) & 1);
    if (is_nulinkpro) {
        LOG_INFO("Adapter is Nu-Link-Pro, target_voltage_mv(%" PRIu16 "), usb_voltage_mv(%" PRIu16 ")",
                 le_to_h_u16(h->databuf + 4 * 3 + 0),
                 le_to_h_u16(h->databuf + 4 * 3 + 2));
 
        h->hardware_config |= HARDWARE_CONFIG_NULINKPRO;
    } else {
        LOG_INFO("Adapter is Nu-Link");
    }
 
    return ERROR_OK;
}
 
static int nulink_usb_idcode(void *handle, uint32_t *idcode)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_idcode");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_CHECK_ID);
    h->cmdidx += 4;
 
    int res = nulink_usb_xfer(handle, h->databuf, 4 * 2);
    if (res != ERROR_OK)
        return res;
 
    *idcode = le_to_h_u32(h->databuf + 4 * 1);
 
    LOG_INFO("IDCODE: 0x%08" PRIX32, *idcode);
 
    return ERROR_OK;
}
 
static int nulink_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_write_debug_reg 0x%08" PRIX32 " 0x%08" PRIX32, addr, val);
 
    nulink_usb_init_buffer(handle, 8 + 12 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_RAM);
    h->cmdidx += 4;
    /* Count of registers */
    h->cmdbuf[h->cmdidx] = 1;
    h->cmdidx += 1;
    /* Array of bool value (u8ReadOld) */
    h->cmdbuf[h->cmdidx] = 0x00;
    h->cmdidx += 1;
    /* Array of bool value (u8Verify) */
    h->cmdbuf[h->cmdidx] = 0x00;
    h->cmdidx += 1;
    /* ignore */
    h->cmdbuf[h->cmdidx] = 0;
    h->cmdidx += 1;
    /* u32Addr */
    h_u32_to_le(h->cmdbuf + h->cmdidx, addr);
    h->cmdidx += 4;
    /* u32Data */
    h_u32_to_le(h->cmdbuf + h->cmdidx, val);
    h->cmdidx += 4;
    /* u32Mask */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0x00000000UL);
    h->cmdidx += 4;
 
    return nulink_usb_xfer(handle, h->databuf, 4 * 2);
}
 
static enum target_state nulink_usb_state(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_CHECK_MCU_STOP);
    h->cmdidx += 4;
 
    int res = nulink_usb_xfer(handle, h->databuf, 4 * 4);
    if (res != ERROR_OK)
        return TARGET_UNKNOWN;
 
    if (!le_to_h_u32(h->databuf + 4 * 2))
        return TARGET_HALTED;
    else
        return TARGET_RUNNING;
}
 
static int nulink_usb_assert_srst(void *handle, int srst)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_assert_srst");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 4);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_MCU_RESET);
    h->cmdidx += 4;
    /* set reset type */
    h_u32_to_le(h->cmdbuf + h->cmdidx, RESET_SYSRESETREQ);
    h->cmdidx += 4;
    /* set connect type */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CONNECT_NORMAL);
    h->cmdidx += 4;
    /* set extMode */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
    h->cmdidx += 4;
 
    return nulink_usb_xfer(handle, h->databuf, 4 * 4);
}
 
static int nulink_usb_reset(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_reset");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 4);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_MCU_RESET);
    h->cmdidx += 4;
    /* set reset type */
    h_u32_to_le(h->cmdbuf + h->cmdidx, RESET_HW);
    h->cmdidx += 4;
    /* set connect type */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CONNECT_NORMAL);
    h->cmdidx += 4;
    /* set extMode */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
    h->cmdidx += 4;
 
    return nulink_usb_xfer(handle, h->databuf, 4 * 4);
}
 
static int nulink_usb_run(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_run");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_MCU_FREE_RUN);
    h->cmdidx += 4;
 
    return nulink_usb_xfer(handle, h->databuf, 4 * 4);
}
 
static int nulink_usb_halt(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_halt");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_MCU_STOP_RUN);
    h->cmdidx += 4;
 
    int res = nulink_usb_xfer(handle, h->databuf, 4 * 4);
 
    LOG_DEBUG("Nu-Link stop_pc 0x%08" PRIx32, le_to_h_u32(h->databuf + 4));
 
    return res;
}
 
static int nulink_usb_step(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_step");
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 4 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_MCU_STEP_RUN);
    h->cmdidx += 4;
 
    int res = nulink_usb_xfer(handle, h->databuf, 4 * 4);
 
    LOG_DEBUG("Nu-Link pc 0x%08" PRIx32, le_to_h_u32(h->databuf + 4));
 
    return res;
}
 
static int nulink_usb_read_reg(void *handle, unsigned int regsel, uint32_t *val)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 8 + 12 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_REG);
    h->cmdidx += 4;
    /* Count of registers */
    h->cmdbuf[h->cmdidx] = 1;
    h->cmdidx += 1;
    /* Array of bool value (u8ReadOld) */
    h->cmdbuf[h->cmdidx] = 0xFF;
    h->cmdidx += 1;
    /* Array of bool value (u8Verify) */
    h->cmdbuf[h->cmdidx] = 0x00;
    h->cmdidx += 1;
    /* ignore */
    h->cmdbuf[h->cmdidx] = 0;
    h->cmdidx += 1;
    /* u32Addr */
    h_u32_to_le(h->cmdbuf + h->cmdidx, regsel);
    h->cmdidx += 4;
    /* u32Data */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
    h->cmdidx += 4;
    /* u32Mask */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFFFFFFUL);
    h->cmdidx += 4;
 
    int res = nulink_usb_xfer(handle, h->databuf, 4 * 2);
 
    *val = le_to_h_u32(h->databuf + 4 * 1);
 
    return res;
}
 
static int nulink_usb_write_reg(void *handle, unsigned int regsel, uint32_t val)
{
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    nulink_usb_init_buffer(handle, 8 + 12 * 1);
    /* set command ID */
    h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_REG);
    h->cmdidx += 4;
    /* Count of registers */
    h->cmdbuf[h->cmdidx] = 1;
    h->cmdidx += 1;
    /* Array of bool value (u8ReadOld) */
    h->cmdbuf[h->cmdidx] = 0x00;
    h->cmdidx += 1;
    /* Array of bool value (u8Verify) */
    h->cmdbuf[h->cmdidx] = 0x00;
    h->cmdidx += 1;
    /* ignore */
    h->cmdbuf[h->cmdidx] = 0;
    h->cmdidx += 1;
    /* u32Addr */
    h_u32_to_le(h->cmdbuf + h->cmdidx, regsel);
    h->cmdidx += 4;
    /* u32Data */
    h_u32_to_le(h->cmdbuf + h->cmdidx, val);
    h->cmdidx += 4;
    /* u32Mask */
    h_u32_to_le(h->cmdbuf + h->cmdidx, 0x00000000UL);
    h->cmdidx += 4;
 
    return nulink_usb_xfer(handle, h->databuf, 4 * 2);
}
 
static int nulink_usb_read_mem8(void *handle, uint32_t addr, uint16_t len,
        uint8_t *buffer)
{
    int res = ERROR_OK;
    uint32_t offset = 0;
    uint32_t bytes_remaining = 12;
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_read_mem8: addr 0x%08" PRIx32 ", len %" PRId16, addr, len);
 
    assert(handle);
 
    /* check whether data is word aligned */
    if (addr % 4) {
        uint32_t aligned_addr = addr / 4;
        aligned_addr = aligned_addr * 4;
        offset = addr - aligned_addr;
        LOG_DEBUG("nulink_usb_read_mem8: unaligned address addr 0x%08" PRIx32
                "/aligned addr 0x%08" PRIx32 " offset %" PRIu32,
                addr, aligned_addr, offset);
 
        addr = aligned_addr;
    }
 
    while (len) {
        unsigned int count;
 
        if (len < bytes_remaining)
            bytes_remaining = len;
 
        if (len < 4)
            count = 1;
        else
            count = 2;
 
        nulink_usb_init_buffer(handle, 8 + 12 * count);
        /* set command ID */
        h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_RAM);
        h->cmdidx += 4;
        /* Count of registers */
        h->cmdbuf[h->cmdidx] = count;
        h->cmdidx += 1;
        /* Array of bool value (u8ReadOld) */
        h->cmdbuf[h->cmdidx] = 0xFF;
        h->cmdidx += 1;
        /* Array of bool value (u8Verify) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* ignore */
        h->cmdbuf[h->cmdidx] = 0;
        h->cmdidx += 1;
 
        for (unsigned int i = 0; i < count; i++) {
            /* u32Addr */
            h_u32_to_le(h->cmdbuf + h->cmdidx, addr);
            h->cmdidx += 4;
            /* u32Data */
            h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
            h->cmdidx += 4;
            /* u32Mask */
            h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFFFFFFUL);
            h->cmdidx += 4;
            /* proceed to the next one  */
            addr += 4;
        }
 
        res = nulink_usb_xfer(handle, h->databuf, 4 * count * 2);
        if (res != ERROR_OK)
            break;
 
        /* fill in the output buffer */
        for (unsigned int i = 0; i < count; i++) {
            if (i == 0)
                memcpy(buffer, h->databuf + 4 + offset, len);
            else
                memcpy(buffer + 2 * i, h->databuf + 4 * (2 * i + 1), len - 2);
        }
 
        if (len >= bytes_remaining)
            len -= bytes_remaining;
    }
 
    return res;
}
 
static int nulink_usb_write_mem8(void *handle, uint32_t addr, uint16_t len,
        const uint8_t *buffer)
{
    int res = ERROR_OK;
    uint32_t offset = 0;
    uint32_t bytes_remaining = 12;
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_write_mem8: addr 0x%08" PRIx32 ", len %" PRIu16, addr, len);
 
    assert(handle);
 
    /* check whether data is word aligned */
    if (addr % 4) {
        uint32_t aligned_addr = addr / 4;
        aligned_addr = aligned_addr * 4;
        offset = addr - aligned_addr;
        LOG_DEBUG("nulink_usb_write_mem8: address not aligned. addr(0x%08" PRIx32
                ")/aligned_addr(0x%08" PRIx32 ")/offset(%" PRIu32 ")",
                addr, aligned_addr, offset);
 
        addr = aligned_addr;
    }
 
    while (len) {
        unsigned int count;
 
        if (len < bytes_remaining)
            bytes_remaining = len;
 
        if (len < 4)
            count = 1;
        else
            count = 2;
 
        nulink_usb_init_buffer(handle, 8 + 12 * count);
        /* set command ID */
        h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_RAM);
        h->cmdidx += 4;
        /* Count of registers */
        h->cmdbuf[h->cmdidx] = count;
        h->cmdidx += 1;
        /* Array of bool value (u8ReadOld) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* Array of bool value (u8Verify) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* ignore */
        h->cmdbuf[h->cmdidx] = 0;
        h->cmdidx += 1;
 
        for (unsigned int i = 0; i < count; i++) {
            /* u32Addr */
            h_u32_to_le(h->cmdbuf + h->cmdidx, addr);
            h->cmdidx += 4;
            /* u32Data */
            uint32_t u32buffer = buf_get_u32(buffer, 0, len * 8);
            u32buffer = (u32buffer << offset * 8);
            h_u32_to_le(h->cmdbuf + h->cmdidx, u32buffer);
            h->cmdidx += 4;
            /* u32Mask */
            if (i == 0) {
                if (offset == 0) {
                    if (len == 1) {
                        h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFFFF00UL);
                        LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0xFFFFFF00", i);
                    } else {
                        h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFF0000UL);
                        LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0xFFFF0000", i);
                    }
                } else {
                    if (len == 1) {
                        h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFF00FFFFUL);
                        LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0xFF00FFFF", i);
 
                    } else {
                        h_u32_to_le(h->cmdbuf + h->cmdidx, 0x0000FFFFUL);
                        LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0x0000FFFF", i);
                    }
                }
            } else {
                if (len == 4) {
                    h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFF0000UL);
                    LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0xFFFF0000", i);
                } else {
                    h_u32_to_le(h->cmdbuf + h->cmdidx, 0x00000000UL);
                    LOG_DEBUG("nulink_usb_write_mem8: count(%u), mask: 0x00000000", i);
                }
            }
            h->cmdidx += 4;
 
            /* proceed to the next one */
            addr += 4;
            buffer += 4;
        }
 
        res = nulink_usb_xfer(handle, h->databuf, 4 * count * 2);
        if (res != ERROR_OK)
            break;
 
        if (len >= bytes_remaining)
            len -= bytes_remaining;
    }
 
    return res;
}
 
static int nulink_usb_read_mem32(void *handle, uint32_t addr, uint16_t len,
        uint8_t *buffer)
{
    int res = ERROR_OK;
    uint32_t bytes_remaining = 12;
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    /* data must be a multiple of 4 and word aligned */
    if (len % 4 || addr % 4) {
        LOG_ERROR("Invalid data alignment");
        return ERROR_TARGET_UNALIGNED_ACCESS;
    }
 
    while (len) {
        if (len < bytes_remaining)
            bytes_remaining = len;
 
        unsigned int count = bytes_remaining / 4;
 
        nulink_usb_init_buffer(handle, 8 + 12 * count);
        /* set command ID */
        h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_RAM);
        h->cmdidx += 4;
        /* Count of registers */
        h->cmdbuf[h->cmdidx] = count;
        h->cmdidx += 1;
        /* Array of bool value (u8ReadOld) */
        h->cmdbuf[h->cmdidx] = 0xFF;
        h->cmdidx += 1;
        /* Array of bool value (u8Verify) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* ignore */
        h->cmdbuf[h->cmdidx] = 0;
        h->cmdidx += 1;
 
        for (unsigned int i = 0; i < count; i++) {
            /* u32Addr */
            h_u32_to_le(h->cmdbuf + h->cmdidx, addr);
            h->cmdidx += 4;
            /* u32Data */
            h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
            h->cmdidx += 4;
            /* u32Mask */
            h_u32_to_le(h->cmdbuf + h->cmdidx, 0xFFFFFFFFUL);
            h->cmdidx += 4;
            /* proceed to the next one  */
            addr += 4;
        }
 
        res = nulink_usb_xfer(handle, h->databuf, 4 * count * 2);
 
        /* fill in the output buffer */
        for (unsigned int i = 0; i < count; i++) {
            memcpy(buffer, h->databuf + 4 * (2 * i + 1), 4);
            buffer += 4;
        }
 
        if (len >= bytes_remaining)
            len -= bytes_remaining;
        else
            len = 0;
    }
 
    return res;
}
 
static int nulink_usb_write_mem32(void *handle, uint32_t addr, uint16_t len,
        const uint8_t *buffer)
{
    int res = ERROR_OK;
    uint32_t bytes_remaining = 12;
    struct nulink_usb_handle *h = handle;
 
    assert(handle);
 
    /* data must be a multiple of 4 and word aligned */
    if (len % 4 || addr % 4) {
        LOG_ERROR("Invalid data alignment");
        return ERROR_TARGET_UNALIGNED_ACCESS;
    }
 
    while (len) {
        if (len < bytes_remaining)
            bytes_remaining = len;
 
        unsigned int count = bytes_remaining / 4;
 
        nulink_usb_init_buffer(handle, 8 + 12 * count);
        /* set command ID */
        h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_WRITE_RAM);
        h->cmdidx += 4;
        /* Count of registers */
        h->cmdbuf[h->cmdidx] = count;
        h->cmdidx += 1;
        /* Array of bool value (u8ReadOld) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* Array of bool value (u8Verify) */
        h->cmdbuf[h->cmdidx] = 0x00;
        h->cmdidx += 1;
        /* ignore */
        h->cmdbuf[h->cmdidx] = 0;
        h->cmdidx += 1;
 
        for (unsigned int i = 0; i < count; i++) {
            /* u32Addr */
            h_u32_to_le(h->cmdbuf + h->cmdidx, addr);
            h->cmdidx += 4;
            /* u32Data */
            uint32_t u32buffer = buf_get_u32(buffer, 0, 32);
            h_u32_to_le(h->cmdbuf + h->cmdidx, u32buffer);
            h->cmdidx += 4;
            /* u32Mask */
            h_u32_to_le(h->cmdbuf + h->cmdidx, 0x00000000);
            h->cmdidx += 4;
 
            /* proceed to the next one */
            addr += 4;
            buffer += 4;
        }
 
        res = nulink_usb_xfer(handle, h->databuf, 4 * count * 2);
 
        if (len >= bytes_remaining)
            len -= bytes_remaining;
        else
            len = 0;
    }
 
    return res;
}
 
static uint32_t nulink_max_block_size(uint32_t tar_autoincr_block, uint32_t address)
{
    uint32_t max_tar_block = (tar_autoincr_block - ((tar_autoincr_block - 1) & address));
 
    if (max_tar_block == 0)
        max_tar_block = 4;
 
    return max_tar_block;
}
 
static int nulink_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, uint8_t *buffer)
{
    int retval = ERROR_OK;
    struct nulink_usb_handle *h = handle;
 
    /* calculate byte count */
    count *= size;
 
    while (count) {
        uint32_t bytes_remaining = nulink_max_block_size(h->max_mem_packet, addr);
 
        if (count < bytes_remaining)
            bytes_remaining = count;
 
        if (bytes_remaining >= 4)
            size = 4;
 
        /* the nulink only supports 8/32bit memory read/writes
         * honour 32bit, all others will be handled as 8bit access */
        if (size == 4) {
            /* When in jtag mode the nulink uses the auto-increment functionality.
             * However it expects us to pass the data correctly, this includes
             * alignment and any page boundaries. We already do this as part of the
             * adi_v5 implementation, but the nulink is a hla adapter and so this
             * needs implementing manually.
             * currently this only affects jtag mode, they do single
             * access in SWD mode - but this may change and so we do it for both modes */
 
            /* we first need to check for any unaligned bytes */
            if (addr % 4) {
                uint32_t head_bytes = 4 - (addr % 4);
                retval = nulink_usb_read_mem8(handle, addr, head_bytes, buffer);
                if (retval != ERROR_OK)
                    return retval;
                buffer += head_bytes;
                addr += head_bytes;
                count -= head_bytes;
                bytes_remaining -= head_bytes;
            }
 
            if (bytes_remaining % 4)
                retval = nulink_usb_read_mem(handle, addr, 1, bytes_remaining, buffer);
            else
                retval = nulink_usb_read_mem32(handle, addr, bytes_remaining, buffer);
        } else {
            retval = nulink_usb_read_mem8(handle, addr, bytes_remaining, buffer);
        }
 
        if (retval != ERROR_OK)
            return retval;
 
        buffer += bytes_remaining;
        addr += bytes_remaining;
        count -= bytes_remaining;
    }
 
    return retval;
}
 
static int nulink_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, const uint8_t *buffer)
{
    int retval = ERROR_OK;
    struct nulink_usb_handle *h = handle;
 
    if (addr < ARM_SRAM_BASE) {
        LOG_DEBUG("nulink_usb_write_mem: address below ARM_SRAM_BASE, not supported.\n");
        return retval;
    }
 
    /* calculate byte count */
    count *= size;
 
    while (count) {
        uint32_t bytes_remaining = nulink_max_block_size(h->max_mem_packet, addr);
 
        if (count < bytes_remaining)
            bytes_remaining = count;
 
        if (bytes_remaining >= 4)
            size = 4;
 
        /* the nulink only supports 8/32bit memory read/writes
         * honour 32bit, all others will be handled as 8bit access */
        if (size == 4) {
            /* When in jtag mode the nulink uses the auto-increment functionality.
             * However it expects us to pass the data correctly, this includes
             * alignment and any page boundaries. We already do this as part of the
             * adi_v5 implementation, but the nulink is a hla adapter and so this
             * needs implementing manually.
             * currently this only affects jtag mode, do single
             * access in SWD mode - but this may change and so we do it for both modes */
 
            /* we first need to check for any unaligned bytes */
            if (addr % 4) {
                uint32_t head_bytes = 4 - (addr % 4);
                retval = nulink_usb_write_mem8(handle, addr, head_bytes, buffer);
                if (retval != ERROR_OK)
                    return retval;
                buffer += head_bytes;
                addr += head_bytes;
                count -= head_bytes;
                bytes_remaining -= head_bytes;
            }
 
            if (bytes_remaining % 4)
                retval = nulink_usb_write_mem(handle, addr, 1, bytes_remaining, buffer);
            else
                retval = nulink_usb_write_mem32(handle, addr, bytes_remaining, buffer);
 
        } else {
            retval = nulink_usb_write_mem8(handle, addr, bytes_remaining, buffer);
        }
 
        if (retval != ERROR_OK)
            return retval;
 
        buffer += bytes_remaining;
        addr += bytes_remaining;
        count -= bytes_remaining;
    }
 
    return retval;
}
 
static int nulink_usb_override_target(const char *targetname)
{
    LOG_DEBUG("nulink_usb_override_target");
 
    return !strcmp(targetname, "cortex_m");
}
 
static int nulink_speed(void *handle, int khz, bool query)
{
    struct nulink_usb_handle *h = handle;
    unsigned long max_ice_clock = khz;
 
    LOG_DEBUG("nulink_speed: query %s", query ? "yes" : "no");
 
    if (max_ice_clock > 12000)
        max_ice_clock = 12000;
    else if ((max_ice_clock == 3 * 512) || (max_ice_clock == 1500))
        max_ice_clock = 1500;
    else if (max_ice_clock >= 1000)
        max_ice_clock = max_ice_clock / 1000 * 1000;
    else
        max_ice_clock = max_ice_clock / 100 * 100;
 
    LOG_DEBUG("Nu-Link nulink_speed: %lu", max_ice_clock);
 
    if (!query) {
        nulink_usb_init_buffer(handle, 4 * 6);
        /* set command ID */
        h_u32_to_le(h->cmdbuf + h->cmdidx, CMD_SET_CONFIG);
        h->cmdidx += 4;
        /* set max SWD clock */
        h_u32_to_le(h->cmdbuf + h->cmdidx, max_ice_clock);
        h->cmdidx += 4;
        /* chip type: NUC_CHIP_TYPE_GENERAL_V6M */
        h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
        h->cmdidx += 4;
        /* IO voltage */
        h_u32_to_le(h->cmdbuf + h->cmdidx, 5000);
        h->cmdidx += 4;
        /* If supply voltage to target or not */
        h_u32_to_le(h->cmdbuf + h->cmdidx, 0);
        h->cmdidx += 4;
        /* USB_FUNC_E: USB_FUNC_HID_BULK */
        h_u32_to_le(h->cmdbuf + h->cmdidx, 2);
        h->cmdidx += 4;
 
        nulink_usb_xfer(handle, h->databuf, 4 * 3);
 
        LOG_DEBUG("nulink_speed: h->hardware_config(%" PRId16 ")", h->hardware_config);
        if (h->hardware_config & HARDWARE_CONFIG_NULINKPRO)
            LOG_INFO("Nu-Link target_voltage_mv[0](%04" PRIx16 "), target_voltage_mv[1](%04" PRIx16
                "), target_voltage_mv[2](%04" PRIx16 "), if_target_power_supplied(%d)",
                le_to_h_u16(h->databuf + 4 * 1 + 0),
                le_to_h_u16(h->databuf + 4 * 1 + 2),
                le_to_h_u16(h->databuf + 4 * 2 + 0),
                le_to_h_u16(h->databuf + 4 * 2 + 2) & 1);
    }
 
    return max_ice_clock;
}
 
static int nulink_usb_close(void *handle)
{
    struct nulink_usb_handle *h = handle;
 
    LOG_DEBUG("nulink_usb_close");
 
    if (h && h->dev_handle)
        hid_close(h->dev_handle);
 
    free(h);
 
    hid_exit();
 
    return ERROR_OK;
}
 
static int nulink_usb_open(struct hl_interface_param *param, void **fd)
{
    struct hid_device_info *devs, *cur_dev;
    uint16_t target_vid = 0;
    uint16_t target_pid = 0;
    wchar_t *target_serial = NULL;
 
    LOG_DEBUG("nulink_usb_open");
 
    if (param->transport != HL_TRANSPORT_SWD)
        return TARGET_UNKNOWN;
 
    if (!param->vid[0] && !param->pid[0]) {
        LOG_ERROR("Missing vid/pid");
        return ERROR_FAIL;
    }
 
    if (hid_init() != 0) {
        LOG_ERROR("unable to open HIDAPI");
        return ERROR_FAIL;
    }
 
    struct nulink_usb_handle *h = calloc(1, sizeof(*h));
    if (!h) {
        LOG_ERROR("Out of memory");
        goto error_open;
    }
 
    const char *serial = adapter_get_required_serial();
    if (serial) {
        size_t len = mbstowcs(NULL, serial, 0);
 
        target_serial = calloc(len + 1, sizeof(wchar_t));
        if (!target_serial) {
            LOG_ERROR("Out of memory");
            goto error_open;
        }
 
        if (mbstowcs(target_serial, serial, len + 1) == (size_t)(-1)) {
            LOG_WARNING("unable to convert serial");
            free(target_serial);
            target_serial = NULL;
        }
    }
 
    devs = hid_enumerate(0, 0);
    cur_dev = devs;
    while (cur_dev) {
        bool found = false;
 
        for (unsigned int i = 0; param->vid[i] || param->pid[i]; i++) {
            if (param->vid[i] == cur_dev->vendor_id && param->pid[i] == cur_dev->product_id) {
                found = true;
                break;
            }
        }
 
        if (found) {
            if (!target_serial)
                break;
            if (cur_dev->serial_number && wcscmp(target_serial, cur_dev->serial_number) == 0)
                break;
        }
 
        cur_dev = cur_dev->next;
    }
    if (cur_dev) {
        target_vid = cur_dev->vendor_id;
        target_pid = cur_dev->product_id;
    }
 
    hid_free_enumeration(devs);
 
    if (target_vid == 0 && target_pid == 0) {
        LOG_ERROR("unable to find Nu-Link");
        goto error_open;
    }
 
    hid_device *dev = hid_open(target_vid, target_pid, target_serial);
    if (!dev) {
        LOG_ERROR("unable to open Nu-Link device 0x%" PRIx16 ":0x%" PRIx16, target_vid, target_pid);
        goto error_open;
    }
 
    h->dev_handle = dev;
    h->usbcmdidx = 0;
 
    switch (target_pid) {
    case NULINK2_USB_PID1:
    case NULINK2_USB_PID2:
        h->hardware_config = HARDWARE_CONFIG_NULINK2;
        h->max_packet_size = NULINK2_HID_MAX_SIZE;
        h->init_buffer = nulink2_usb_init_buffer;
        h->xfer = nulink2_usb_xfer;
        break;
    default:
        h->hardware_config = 0;
        h->max_packet_size = NULINK_HID_MAX_SIZE;
        h->init_buffer = nulink1_usb_init_buffer;
        h->xfer = nulink1_usb_xfer;
        break;
    }
 
    /* get the device version */
    h->cmdsize = 4 * 5;
    int err = nulink_usb_version(h);
    if (err != ERROR_OK) {
        LOG_DEBUG("nulink_usb_version failed with cmdSize(4 * 5)");
        h->cmdsize = 4 * 6;
        err = nulink_usb_version(h);
        if (err != ERROR_OK)
            LOG_DEBUG("nulink_usb_version failed with cmdSize(4 * 6)");
    }
 
    /* SWD clock rate : 1MHz */
    nulink_speed(h, 1000, false);
 
    /* get cpuid, so we can determine the max page size
     * start with a safe default */
    h->max_mem_packet = (1 << 10);
 
    LOG_DEBUG("nulink_usb_open: we manually perform nulink_usb_reset");
    nulink_usb_reset(h);
 
    *fd = h;
 
    free(target_serial);
    return ERROR_OK;
 
error_open:
    nulink_usb_close(h);
    free(target_serial);
 
    return ERROR_FAIL;
}
 
struct hl_layout_api nulink_usb_layout_api = {
    .open = nulink_usb_open,
    .close = nulink_usb_close,
    .idcode = nulink_usb_idcode,
    .state = nulink_usb_state,
    .reset = nulink_usb_reset,
    .assert_srst = nulink_usb_assert_srst,
    .run = nulink_usb_run,
    .halt = nulink_usb_halt,
    .step = nulink_usb_step,
    .read_reg = nulink_usb_read_reg,
    .write_reg = nulink_usb_write_reg,
    .read_mem = nulink_usb_read_mem,
    .write_mem = nulink_usb_write_mem,
    .write_debug_reg = nulink_usb_write_debug_reg,
    .override_target = nulink_usb_override_target,
    .speed = nulink_speed,
};