bitq.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
*   Copyright (C) 2007 by Pavel Chromy                                    *
*   chromy@asix.cz                                                        *
***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <jtag/jtag.h>
#include "bitq.h"
#include <jtag/interface.h>
 
struct bitq_interface *bitq_interface; /* low level bit queue interface */
 
/* state of input queue */
struct bitq_state {
    struct jtag_command *cmd; /* command currently processed */
    unsigned int field_idx; /* index of field currently being processed */
    unsigned int bit_pos; /* position of bit currently being processed */
    int status; /* processing status */
};
static struct bitq_state bitq_in_state;
 
/*
 * input queue processing does not use jtag_read_buffer() to avoid unnecessary overhead
 * no parameters, makes use of stored state information
 */
static void bitq_in_proc(void)
{
    /* loop through the queue */
    while (bitq_in_state.cmd) {
        /* only JTAG_SCAN command may return data */
        if (bitq_in_state.cmd->type == JTAG_SCAN) {
            /* loop through the fields */
            while (bitq_in_state.field_idx < bitq_in_state.cmd->cmd.scan->num_fields) {
                struct scan_field *field;
                field = &bitq_in_state.cmd->cmd.scan->fields[bitq_in_state.field_idx];
                if (field->in_value) {
                    /* field scanning */
                    while (bitq_in_state.bit_pos < field->num_bits) {
                        /* index of byte being scanned */
                        int in_idx = bitq_in_state.bit_pos / 8;
                        /* mask of next bit to be scanned */
                        uint8_t in_mask = 1 << (bitq_in_state.bit_pos % 8);
 
                        int tdo = bitq_interface->in();
                        if (tdo < 0) {
                            LOG_DEBUG_IO("bitq in EOF");
                            return;
                        }
                        if (in_mask == 0x01)
                            field->in_value[in_idx] = 0;
                        if (tdo)
                            field->in_value[in_idx] |= in_mask;
                        bitq_in_state.bit_pos++;
                    }
                }
 
                bitq_in_state.field_idx++;  /* advance to next field */
                bitq_in_state.bit_pos = 0;  /* start next field from the first bit */
            }
        }
        bitq_in_state.cmd = bitq_in_state.cmd->next;    /* advance to next command */
        bitq_in_state.field_idx = 0;                    /* preselect first field */
    }
}
 
static void bitq_io(int tms, int tdi, int tdo_req)
{
    bitq_interface->out(tms, tdi, tdo_req);
    /* check and process the input queue */
    if (bitq_interface->in_rdy())
        bitq_in_proc();
}
 
static void bitq_end_state(tap_state_t state)
{
    if (!tap_is_state_stable(state)) {
        LOG_ERROR("BUG: %i is not a valid end state", state);
        exit(-1);
    }
    tap_set_end_state(state);
}
 
static void bitq_state_move(tap_state_t new_state)
{
    int i = 0;
    uint8_t  tms_scan;
 
    if (!tap_is_state_stable(tap_get_state()) || !tap_is_state_stable(new_state)) {
        LOG_ERROR("TAP move from or to unstable state");
        exit(-1);
    }
 
    tms_scan = tap_get_tms_path(tap_get_state(), new_state);
    int tms_count = tap_get_tms_path_len(tap_get_state(), new_state);
 
    for (i = 0; i < tms_count; i++) {
        bitq_io(tms_scan & 1, 0, 0);
        tms_scan >>= 1;
    }
 
    tap_set_state(new_state);
}
 
static void bitq_path_move(struct pathmove_command *cmd)
{
    for (unsigned int i = 0; i < cmd->num_states; i++) {
        if (tap_state_transition(tap_get_state(), false) == cmd->path[i])
            bitq_io(0, 0, 0);
        else if (tap_state_transition(tap_get_state(), true) == cmd->path[i])
            bitq_io(1, 0, 0);
        else {
            LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(
                             tap_get_state()), tap_state_name(cmd->path[i]));
            exit(-1);
        }
 
        tap_set_state(cmd->path[i]);
    }
 
    tap_set_end_state(tap_get_state());
}
 
static void bitq_runtest(unsigned int num_cycles)
{
    /* only do a state_move when we're not already in IDLE */
    if (tap_get_state() != TAP_IDLE)
        bitq_state_move(TAP_IDLE);
 
    /* execute num_cycles */
    for (unsigned int i = 0; i < num_cycles; i++)
        bitq_io(0, 0, 0);
 
    /* finish in end_state */
    if (tap_get_state() != tap_get_end_state())
        bitq_state_move(tap_get_end_state());
}
 
static void bitq_scan_field(struct scan_field *field, int do_pause)
{
    int tdo_req;
 
    const uint8_t *out_ptr;
    uint8_t out_mask;
 
    if (field->in_value)
        tdo_req = 1;
    else
        tdo_req = 0;
 
    if (!field->out_value) {
        /* just send zeros and request data from TDO */
        for (unsigned int i = 0; i < (field->num_bits - 1); i++)
            bitq_io(0, 0, tdo_req);
 
        bitq_io(do_pause, 0, tdo_req);
    } else {
        /* send data, and optionally request TDO */
        out_mask = 0x01;
        out_ptr  = field->out_value;
        for (unsigned int i = 0; i < (field->num_bits - 1); i++) {
            bitq_io(0, ((*out_ptr) & out_mask) != 0, tdo_req);
            if (out_mask == 0x80) {
                out_mask = 0x01;
                out_ptr++;
            } else
                out_mask <<= 1;
        }
 
        bitq_io(do_pause, ((*out_ptr) & out_mask) != 0, tdo_req);
    }
 
    if (do_pause) {
        bitq_io(0, 0, 0);
        if (tap_get_state() == TAP_IRSHIFT)
            tap_set_state(TAP_IRPAUSE);
        else if (tap_get_state() == TAP_DRSHIFT)
            tap_set_state(TAP_DRPAUSE);
    }
}
 
static void bitq_scan(struct scan_command *cmd)
{
    if (cmd->ir_scan)
        bitq_state_move(TAP_IRSHIFT);
    else
        bitq_state_move(TAP_DRSHIFT);
 
    unsigned int i;
    for (i = 0; i < cmd->num_fields - 1; i++)
        bitq_scan_field(&cmd->fields[i], 0);
 
    bitq_scan_field(&cmd->fields[i], 1);
}
 
int bitq_execute_queue(struct jtag_command *cmd_queue)
{
    struct jtag_command *cmd = cmd_queue; /* currently processed command */
 
    bitq_in_state.cmd = cmd_queue;
    bitq_in_state.field_idx = 0;
    bitq_in_state.bit_pos   = 0;
    bitq_in_state.status    = ERROR_OK;
 
    while (cmd) {
        switch (cmd->type) {
        case JTAG_RESET:
            LOG_DEBUG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
            if ((cmd->cmd.reset->trst == 1) ||
                    (cmd->cmd.reset->srst &&
                    (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
                tap_set_state(TAP_RESET);
            bitq_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
            if (bitq_interface->in_rdy())
                bitq_in_proc();
            break;
 
        case JTAG_RUNTEST:
            LOG_DEBUG_IO("runtest %u cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state);
            bitq_end_state(cmd->cmd.runtest->end_state);
            bitq_runtest(cmd->cmd.runtest->num_cycles);
            break;
 
        case JTAG_TLR_RESET:
            LOG_DEBUG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
            bitq_end_state(cmd->cmd.statemove->end_state);
            bitq_state_move(tap_get_end_state());   /* unconditional TAP move */
            break;
 
        case JTAG_PATHMOVE:
            LOG_DEBUG_IO("pathmove: %u states, end in %i", cmd->cmd.pathmove->num_states,
                    cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
            bitq_path_move(cmd->cmd.pathmove);
            break;
 
        case JTAG_SCAN:
            LOG_DEBUG_IO("scan end in %i", cmd->cmd.scan->end_state);
            LOG_DEBUG_IO("scan %s", cmd->cmd.scan->ir_scan ? "ir" : "dr");
            bitq_end_state(cmd->cmd.scan->end_state);
            bitq_scan(cmd->cmd.scan);
            if (tap_get_state() != tap_get_end_state())
                bitq_state_move(tap_get_end_state());
            break;
 
        case JTAG_SLEEP:
            LOG_DEBUG_IO("sleep %" PRIu32, cmd->cmd.sleep->us);
            bitq_interface->sleep(cmd->cmd.sleep->us);
            if (bitq_interface->in_rdy())
                bitq_in_proc();
            break;
 
        default:
            LOG_ERROR("BUG: unknown JTAG command type encountered");
            exit(-1);
        }
 
        cmd = cmd->next;
    }
 
    bitq_interface->flush();
    bitq_in_proc();
 
    if (bitq_in_state.cmd) {
        LOG_ERROR("missing data from bitq interface");
        return ERROR_JTAG_QUEUE_FAILED;
    }
    if (bitq_interface->in() >= 0) {
        LOG_ERROR("extra data from bitq interface");
        return ERROR_JTAG_QUEUE_FAILED;
    }
 
    return bitq_in_state.status;
}
 
void bitq_cleanup(void)
{
}