osbdm.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2012 by Jan Dakinevich                                  *
 *   jan.dakinevich@gmail.com                                              *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#   include "config.h"
#endif
 
#include <helper/log.h>
#include <helper/binarybuffer.h>
#include <helper/command.h>
#include <jtag/interface.h>
#include "libusb_helper.h"
 
struct sequence {
    int len;
    void *tms;
    void *tdo;
    const void *tdi;
    struct sequence *next;
};
 
struct queue {
    struct sequence *head;
    struct sequence *tail;
};
 
static struct sequence *queue_add_tail(struct queue *queue, int len)
{
    if (len <= 0) {
        LOG_ERROR("BUG: sequences with zero length are not allowed");
        return NULL;
    }
 
    struct sequence *next;
    next = malloc(sizeof(*next));
    if (next) {
        next->tms = calloc(1, DIV_ROUND_UP(len, 8));
        if (next->tms) {
            next->len = len;
            next->tdo = NULL;
            next->tdi = NULL;
            next->next = NULL;
 
            if (!queue->head) {
                /* Queue is empty at the moment */
                queue->head = next;
            } else {
                /* Queue already contains at least one sequence */
                queue->tail->next = next;
            }
 
            queue->tail = next;
        } else {
            free(next);
            next = NULL;
        }
    }
 
    if (!next)
        LOG_ERROR("Not enough memory");
 
    return next;
}
 
static void queue_drop_head(struct queue *queue)
{
    struct sequence *head = queue->head->next; /* New head */
    free(queue->head->tms);
    free(queue->head);
    queue->head = head;
}
 
static void queue_free(struct queue *queue)
{
    if (queue) {
        while (queue->head)
            queue_drop_head(queue);
 
        free(queue);
    }
}
 
static struct queue *queue_alloc(void)
{
    struct queue *queue = malloc(sizeof(*queue));
    if (queue)
        queue->head = NULL;
    else
        LOG_ERROR("Not enough memory");
 
    return queue;
}
 
/* Size of usb communication buffer */
#define OSBDM_USB_BUFSIZE 64
/* Timeout for USB transfer, ms */
#define OSBDM_USB_TIMEOUT 1000
/* Write end point */
#define OSBDM_USB_EP_WRITE 0x01
/* Read end point */
#define OSBDM_USB_EP_READ 0x82
 
/* Initialize OSBDM device */
#define OSBDM_CMD_INIT 0x11
/* Execute special, not-BDM command. But only this
 * command is used for JTAG operation */
#define OSBDM_CMD_SPECIAL 0x27
/* Execute JTAG swap (tms/tdi -> tdo) */
#define OSBDM_CMD_SPECIAL_SWAP 0x05
/* Reset control */
#define OSBDM_CMD_SPECIAL_SRST 0x01
/* Maximum bit-length in one swap */
#define OSBDM_SWAP_MAX (((OSBDM_USB_BUFSIZE - 6) / 5) * 16)
 
/* Lists of valid VID/PID pairs
 */
static const uint16_t osbdm_vid[] = { 0x15a2, 0x15a2, 0x15a2, 0 };
static const uint16_t osbdm_pid[] = { 0x0042, 0x0058, 0x005e, 0 };
 
struct osbdm {
    struct libusb_device_handle *devh; /* USB handle */
    uint8_t buffer[OSBDM_USB_BUFSIZE]; /* Data to send and receive */
    int count; /* Count data to send and to read */
};
 
/* osbdm instance
 */
static struct osbdm osbdm_context;
 
static int osbdm_send_and_recv(struct osbdm *osbdm)
{
    /* Send request */
    int count, ret;
 
    ret = jtag_libusb_bulk_write(osbdm->devh, OSBDM_USB_EP_WRITE,
                     (char *)osbdm->buffer, osbdm->count,
                     OSBDM_USB_TIMEOUT, &count);
    if (ret || count != osbdm->count) {
        LOG_ERROR("OSBDM communication error: can't write");
        return ERROR_FAIL;
    }
 
    /* Save command code for next checking */
    uint8_t cmd_saved = osbdm->buffer[0];
 
    /* Reading answer */
    ret = jtag_libusb_bulk_read(osbdm->devh, OSBDM_USB_EP_READ,
                    (char *)osbdm->buffer, OSBDM_USB_BUFSIZE,
                    OSBDM_USB_TIMEOUT, &osbdm->count);
    /* Now perform basic checks for data sent by BDM device
     */
    if (ret) {
        LOG_ERROR("OSBDM communication error: can't read");
        return ERROR_FAIL;
    }
 
    if (osbdm->count < 2) {
        LOG_ERROR("OSBDM communication error: reply too small");
        return ERROR_FAIL;
    }
 
    if (osbdm->count != osbdm->buffer[1])  {
        LOG_ERROR("OSBDM communication error: reply size mismatch");
        return ERROR_FAIL;
    }
 
    if (cmd_saved != osbdm->buffer[0]) {
        LOG_ERROR("OSBDM communication error: reply command mismatch");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int osbdm_srst(struct osbdm *osbdm, int srst)
{
    osbdm->count = 0;
    (void)memset(osbdm->buffer, 0, OSBDM_USB_BUFSIZE);
 
    /* Composing request
     */
    osbdm->buffer[osbdm->count++] = OSBDM_CMD_SPECIAL; /* Command */
    osbdm->buffer[osbdm->count++] = OSBDM_CMD_SPECIAL_SRST; /* Subcommand */
    /* Length in bytes - not used */
    osbdm->buffer[osbdm->count++] = 0;
    osbdm->buffer[osbdm->count++] = 0;
    /* SRST state */
    osbdm->buffer[osbdm->count++] = (srst ? 0 : 0x08);
 
    /* Sending data
     */
    if (osbdm_send_and_recv(osbdm) != ERROR_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
static int osbdm_swap(struct osbdm *osbdm, void *tms, void *tdi,
    void *tdo, int length)
{
    if (length > OSBDM_SWAP_MAX) {
        LOG_ERROR("BUG: bit sequence too long");
        return ERROR_FAIL;
    }
 
    if (length <= 0) {
        LOG_ERROR("BUG: bit sequence equal or less than 0");
        return ERROR_FAIL;
    }
 
    int swap_count = DIV_ROUND_UP(length, 16);
 
    /* cleanup */
    osbdm->count = 0;
    (void)memset(osbdm->buffer, 0, OSBDM_USB_BUFSIZE);
 
    /* Composing request
     */
 
    osbdm->buffer[osbdm->count++] = OSBDM_CMD_SPECIAL; /* Command */
    osbdm->buffer[osbdm->count++] = OSBDM_CMD_SPECIAL_SWAP; /* Subcommand */
    /* Length in bytes - not used */
    osbdm->buffer[osbdm->count++] = 0;
    osbdm->buffer[osbdm->count++] = 0;
    /* Swap count */
    osbdm->buffer[osbdm->count++] = 0;
    osbdm->buffer[osbdm->count++] = (uint8_t)swap_count;
 
    for (int bit_idx = 0; bit_idx < length; ) {
        /* Bit count in swap */
        int bit_count = length - bit_idx;
        if (bit_count > 16)
            bit_count = 16;
 
        osbdm->buffer[osbdm->count++] = (uint8_t)bit_count;
 
        /* Copying TMS and TDI data to output buffer */
        uint32_t tms_data = buf_get_u32(tms, bit_idx, bit_count);
        uint32_t tdi_data = buf_get_u32(tdi, bit_idx, bit_count);
        osbdm->buffer[osbdm->count++] = (uint8_t)(tdi_data >> 8);
        osbdm->buffer[osbdm->count++] = (uint8_t)tdi_data;
        osbdm->buffer[osbdm->count++] = (uint8_t)(tms_data >> 8);
        osbdm->buffer[osbdm->count++] = (uint8_t)tms_data;
 
        /* Next bit offset */
        bit_idx += bit_count;
    }
 
    assert(osbdm->count <= OSBDM_USB_BUFSIZE);
 
    /* Sending data
     */
    if (osbdm_send_and_recv(osbdm) != ERROR_OK)
        return ERROR_FAIL;
 
    /*  Extra check
     */
    if (((osbdm->buffer[2] << 8) | osbdm->buffer[3]) != 2 * swap_count) {
        LOG_ERROR("OSBDM communication error: invalid swap command reply");
        return ERROR_FAIL;
    }
 
    /* Copy TDO response
     */
    uint8_t *buffer = osbdm->buffer + 4;
    for (int bit_idx = 0; bit_idx < length; ) {
        int bit_count = length - bit_idx;
        if (bit_count > 16)
            bit_count = 16;
 
        /* Prepare data */
        uint32_t tdo_data = 0;
        tdo_data |= (*buffer++) << 8;
        tdo_data |= (*buffer++);
        tdo_data >>= (16 - bit_count);
 
        /* Copy TDO to return */
        buf_set_u32(tdo, bit_idx, bit_count, tdo_data);
 
        bit_idx += bit_count;
    }
 
    return ERROR_OK;
}
 
static int osbdm_flush(struct osbdm *osbdm, struct queue *queue)
{
    uint8_t tms[DIV_ROUND_UP(OSBDM_SWAP_MAX, 8)];
    uint8_t tdi[DIV_ROUND_UP(OSBDM_SWAP_MAX, 8)];
    uint8_t tdo[DIV_ROUND_UP(OSBDM_SWAP_MAX, 8)];
 
    int seq_back_len = 0;
 
    while (queue->head) {
        (void)memset(tms, 0, sizeof(tms));
        (void)memset(tdi, 0, sizeof(tdi));
        (void)memset(tdo, 0, sizeof(tdo));
 
        int seq_len;
        int swap_len;
        struct sequence *seq;
 
        /* Copy from queue to tms/tdi streams
         */
        seq = queue->head;
        seq_len = seq_back_len;
        swap_len = 0;
 
        while (seq && swap_len != OSBDM_SWAP_MAX) {
            /* Count bit for copy at this iteration.
             * len should fit into remaining space
             * in tms/tdo bitstreams
             */
            int len = seq->len - seq_len;
            if (len > OSBDM_SWAP_MAX - swap_len)
                len = OSBDM_SWAP_MAX - swap_len;
 
            /* Set tms data */
            buf_set_buf(seq->tms, seq_len, tms, swap_len, len);
 
            /* Set tdi data if they exists */
            if (seq->tdi)
                buf_set_buf(seq->tdi, seq_len, tdi, swap_len, len);
 
            swap_len += len;
            seq_len += len;
            if (seq_len == seq->len) {
                seq = seq->next; /* Move to next sequence */
                seq_len = 0;
            }
        }
 
        if (osbdm_swap(osbdm, tms, tdi, tdo, swap_len))
            return ERROR_FAIL;
 
        /* Copy from tdo stream to queue
         */
 
        for (int swap_back_len = 0; swap_back_len < swap_len; ) {
            int len = queue->head->len - seq_back_len;
            if (len > swap_len - swap_back_len)
                len = swap_len - swap_back_len;
 
            if (queue->head->tdo)
                buf_set_buf(tdo, swap_back_len, queue->head->tdo, seq_back_len, len);
 
            swap_back_len += len;
            seq_back_len += len;
            if (seq_back_len == queue->head->len) {
                queue_drop_head(queue);
                seq_back_len = 0;
            }
        }
    }
 
    return ERROR_OK;
}
 
/*  Basic operation for opening USB device */
static int osbdm_open(struct osbdm *osbdm)
{
    (void)memset(osbdm, 0, sizeof(*osbdm));
    if (jtag_libusb_open(osbdm_vid, osbdm_pid, NULL, &osbdm->devh, NULL) != ERROR_OK)
        return ERROR_FAIL;
 
    if (libusb_claim_interface(osbdm->devh, 0) != ERROR_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
static int osbdm_quit(void)
{
    jtag_libusb_close(osbdm_context.devh);
    return ERROR_OK;
}
 
static int osbdm_add_pathmove(
    struct queue *queue,
    tap_state_t *path,
    int num_states)
{
    assert(num_states <= 32);
 
    struct sequence *next = queue_add_tail(queue, num_states);
    if (!next) {
        LOG_ERROR("BUG: can't allocate bit sequence");
        return ERROR_FAIL;
    }
 
    uint32_t tms = 0;
    for (int i = 0; i < num_states; i++) {
        if (tap_state_transition(tap_get_state(), 1) == path[i]) {
            tms |= (1 << i);
        } else if (tap_state_transition(tap_get_state(), 0) == path[i]) {
            tms &= ~(1 << i); /* This line not so needed */
        } else {
            LOG_ERROR("BUG: %s -> %s isn't a valid TAP state transition",
                tap_state_name(tap_get_state()),
                tap_state_name(path[i]));
            return ERROR_FAIL;
        }
 
        tap_set_state(path[i]);
    }
 
    buf_set_u32(next->tms, 0, num_states, tms);
    tap_set_end_state(tap_get_state());
 
    return ERROR_OK;
}
 
static int osbdm_add_statemove(
    struct queue *queue,
    tap_state_t new_state,
    int skip_first)
{
    int len = 0;
    int tms = 0;
 
    tap_set_end_state(new_state);
    if (tap_get_end_state() == TAP_RESET) {
        /* Ignore current state */
        tms = 0xff;
        len = 5;
    } else if (tap_get_state() != tap_get_end_state()) {
        tms = tap_get_tms_path(tap_get_state(), new_state);
        len = tap_get_tms_path_len(tap_get_state(), new_state);
    }
 
    if (len && skip_first) {
        len--;
        tms >>= 1;
    }
 
    if (len) {
        struct sequence *next = queue_add_tail(queue, len);
        if (!next) {
            LOG_ERROR("BUG: can't allocate bit sequence");
            return ERROR_FAIL;
        }
        buf_set_u32(next->tms, 0, len, tms);
    }
 
    tap_set_state(tap_get_end_state());
    return ERROR_OK;
}
 
static int osbdm_add_stableclocks(
    struct queue *queue,
    int count)
{
    if (!tap_is_state_stable(tap_get_state())) {
        LOG_ERROR("BUG: current state (%s) is not stable",
            tap_state_name(tap_get_state()));
        return ERROR_FAIL;
    }
 
    struct sequence *next = queue_add_tail(queue, count);
    if (!next) {
        LOG_ERROR("BUG: can't allocate bit sequence");
        return ERROR_FAIL;
    }
 
    if (tap_get_state() == TAP_RESET)
        (void)memset(next->tms, 0xff, DIV_ROUND_UP(count, 8));
 
    return ERROR_OK;
}
 
static int osbdm_add_tms(
    struct queue *queue,
    const uint8_t *tms,
    int num_bits)
{
    struct sequence *next = queue_add_tail(queue, num_bits);
    if (!next) {
        LOG_ERROR("BUG: can't allocate bit sequence");
        return ERROR_FAIL;
    }
    buf_set_buf(tms, 0, next->tms, 0, num_bits);
 
    return ERROR_OK;
}
 
static int osbdm_add_scan(
    struct queue *queue,
    struct scan_field *fields,
    int num_fields,
    tap_state_t end_state,
    bool ir_scan)
{
    /* Move to desired shift state */
    if (ir_scan) {
        if (tap_get_state() != TAP_IRSHIFT) {
            if (osbdm_add_statemove(queue, TAP_IRSHIFT, 0) != ERROR_OK)
                return ERROR_FAIL;
        }
    } else {
        if (tap_get_state() != TAP_DRSHIFT) {
            if (osbdm_add_statemove(queue, TAP_DRSHIFT, 0) != ERROR_OK)
                return ERROR_FAIL;
        }
    }
 
    /* Add scan */
    tap_set_end_state(end_state);
    for (int idx = 0; idx < num_fields; idx++) {
        struct sequence *next = queue_add_tail(queue, fields[idx].num_bits);
        if (!next) {
            LOG_ERROR("Can't allocate bit sequence");
            return ERROR_FAIL;
        }
 
        (void)memset(next->tms, 0, DIV_ROUND_UP(fields[idx].num_bits, 8));
        next->tdi = fields[idx].out_value;
        next->tdo = fields[idx].in_value;
    }
 
    /* Move to end state
     */
    if (tap_get_state() != tap_get_end_state()) {
        /* Exit from IRSHIFT/DRSHIFT */
        buf_set_u32(queue->tail->tms, queue->tail->len - 1, 1, 1);
 
        /* Move with skip_first flag */
        if (osbdm_add_statemove(queue, tap_get_end_state(), 1) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int osbdm_add_runtest(
    struct queue *queue,
    int num_cycles,
    tap_state_t end_state)
{
    if (osbdm_add_statemove(queue, TAP_IDLE, 0) != ERROR_OK)
        return ERROR_FAIL;
 
    if (osbdm_add_stableclocks(queue, num_cycles) != ERROR_OK)
        return ERROR_FAIL;
 
    if (osbdm_add_statemove(queue, end_state, 0) != ERROR_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
static int osbdm_execute_command(
    struct osbdm *osbdm,
    struct queue *queue,
    struct jtag_command *cmd)
{
    int retval = ERROR_OK;
 
    switch (cmd->type) {
    case JTAG_RESET:
        if (cmd->cmd.reset->trst) {
            LOG_ERROR("BUG: nTRST signal is not supported");
            retval = ERROR_FAIL;
        } else {
            retval = osbdm_flush(osbdm, queue);
            if (retval == ERROR_OK)
                retval = osbdm_srst(osbdm, cmd->cmd.reset->srst);
        }
        break;
 
    case JTAG_PATHMOVE:
        retval = osbdm_add_pathmove(
            queue,
            cmd->cmd.pathmove->path,
            cmd->cmd.pathmove->num_states);
        break;
 
    case JTAG_TLR_RESET:
        retval = osbdm_add_statemove(
            queue,
            cmd->cmd.statemove->end_state,
            0);
        break;
 
    case JTAG_STABLECLOCKS:
        retval = osbdm_add_stableclocks(
            queue,
            cmd->cmd.stableclocks->num_cycles);
        break;
 
    case JTAG_TMS:
        retval = osbdm_add_tms(
            queue,
            cmd->cmd.tms->bits,
            cmd->cmd.tms->num_bits);
        break;
 
    case JTAG_SCAN:
        retval = osbdm_add_scan(
            queue,
            cmd->cmd.scan->fields,
            cmd->cmd.scan->num_fields,
            cmd->cmd.scan->end_state,
            cmd->cmd.scan->ir_scan);
        break;
 
    case JTAG_SLEEP:
        retval = osbdm_flush(osbdm, queue);
        if (retval == ERROR_OK)
            jtag_sleep(cmd->cmd.sleep->us);
        break;
 
    case JTAG_RUNTEST:
        retval = osbdm_add_runtest(
            queue,
            cmd->cmd.runtest->num_cycles,
            cmd->cmd.runtest->end_state);
        break;
 
    default:
        LOG_ERROR("BUG: unknown JTAG command type encountered");
        retval = ERROR_FAIL;
        break;
    }
 
    return retval;
}
 
static int osbdm_execute_queue(struct jtag_command *cmd_queue)
{
    int retval = ERROR_OK;
 
    struct queue *queue = queue_alloc();
    if (!queue) {
        LOG_ERROR("BUG: can't allocate bit queue");
        retval = ERROR_FAIL;
    } else {
        struct jtag_command *cmd = cmd_queue;
 
        while (retval == ERROR_OK && cmd) {
            retval = osbdm_execute_command(&osbdm_context, queue, cmd);
            cmd = cmd->next;
        }
 
        if (retval == ERROR_OK)
            retval = osbdm_flush(&osbdm_context, queue);
 
        queue_free(queue);
    }
 
    if (retval != ERROR_OK) {
        LOG_ERROR("FATAL: can't execute jtag command");
        exit(-1);
    }
 
    return retval;
}
 
static int osbdm_init(void)
{
    /* Open device */
    if (osbdm_open(&osbdm_context) != ERROR_OK) {
        LOG_ERROR("Can't open OSBDM device");
        return ERROR_FAIL;
    } else {
        /* Device successfully opened */
        LOG_DEBUG("OSBDM init");
    }
 
    /* Perform initialize command */
    osbdm_context.count = 0;
    osbdm_context.buffer[osbdm_context.count++] = OSBDM_CMD_INIT;
    if (osbdm_send_and_recv(&osbdm_context) != ERROR_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
static struct jtag_interface osbdm_interface = {
    .execute_queue = osbdm_execute_queue,
};
 
struct adapter_driver osbdm_adapter_driver = {
    .name = "osbdm",
    .transports = jtag_only,
 
    .init = osbdm_init,
    .quit = osbdm_quit,
 
    .jtag_ops = &osbdm_interface,
};