arc_jtag.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2013-2014,2019-2020 Synopsys, Inc.                      *
 *   Frank Dols <frank.dols@synopsys.com>                                  *
 *   Mischa Jonker <mischa.jonker@synopsys.com>                            *
 *   Anton Kolesov <anton.kolesov@synopsys.com>                            *
 *   Evgeniy Didin <didin@synopsys.com>                                    *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "arc.h"
 
/*
 * This functions sets instruction register in TAP. TAP end state is always
 * IRPAUSE.
 *
 * @param jtag_info
 * @param new_instr Instruction to write to instruction register.
 */
static void arc_jtag_enque_write_ir(struct arc_jtag *jtag_info, uint32_t
        new_instr)
{
    uint32_t current_instr;
    struct jtag_tap *tap;
    uint8_t instr_buffer[sizeof(uint32_t)] = {0};
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    tap = jtag_info->tap;
 
    /* Do not set instruction if it is the same as current. */
    current_instr = buf_get_u32(tap->cur_instr, 0, tap->ir_length);
    if (current_instr == new_instr)
        return;
 
    struct scan_field field = {
        .num_bits = tap->ir_length,
        .out_value = instr_buffer
    };
    buf_set_u32(instr_buffer, 0, field.num_bits, new_instr);
 
    /* From code in src/jtag/drivers/driver.c it look like that fields are
     * copied so it is OK that field in this function is allocated in stack and
     * thus this memory will be repurposed before jtag_execute_queue() will be
     * invoked. */
    jtag_add_ir_scan(tap, &field, TAP_IRPAUSE);
}
 
static void arc_jtag_enque_read_dr(struct arc_jtag *jtag_info, uint8_t *data,
        tap_state_t end_state)
{
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    struct scan_field field = {
        .num_bits = 32,
        .in_value = data
    };
 
    jtag_add_dr_scan(jtag_info->tap, 1, &field, end_state);
}
 
static void arc_jtag_enque_write_dr(struct arc_jtag *jtag_info, uint32_t data,
        tap_state_t end_state)
{
    uint8_t out_value[sizeof(uint32_t)] = {0};
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    buf_set_u32(out_value, 0, 32, data);
 
    struct scan_field field = {
        .num_bits = 32,
        .out_value = out_value
    };
 
    jtag_add_dr_scan(jtag_info->tap, 1, &field, end_state);
}
 
 
static void arc_jtag_enque_set_transaction(struct arc_jtag *jtag_info,
        uint32_t new_trans, tap_state_t end_state)
{
    uint8_t out_value[sizeof(uint32_t)] = {0};
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    /* No need to do anything. */
    if (jtag_info->cur_trans == new_trans)
        return;
 
    /* Set instruction. We used to call write_ir at upper levels, however
     * write_ir-write_transaction were constantly in pair, so to avoid code
     * duplication this function does it self. For this reasons it is "set"
     * instead of "write". */
    arc_jtag_enque_write_ir(jtag_info, ARC_TRANSACTION_CMD_REG);
    buf_set_u32(out_value, 0, ARC_TRANSACTION_CMD_REG_LENGTH, new_trans);
    struct scan_field field = {
        .num_bits = ARC_TRANSACTION_CMD_REG_LENGTH,
        .out_value = out_value
    };
 
    jtag_add_dr_scan(jtag_info->tap, 1, &field, end_state);
    jtag_info->cur_trans = new_trans;
}
 
static void arc_jtag_enque_reset_transaction(struct arc_jtag *jtag_info)
{
    arc_jtag_enque_set_transaction(jtag_info, ARC_JTAG_CMD_NOP, TAP_IDLE);
}
 
static void arc_jtag_enque_status_read(struct arc_jtag * const jtag_info,
    uint8_t * const buffer)
{
    assert(jtag_info);
    assert(jtag_info->tap);
    assert(buffer);
 
    /* first writing code(0x8) of jtag status register in IR */
    arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_STATUS_REG);
    /* Now reading dr performs jtag status register read */
    arc_jtag_enque_read_dr(jtag_info, buffer, TAP_IDLE);
}
 
/* ----- Exported JTAG functions ------------------------------------------- */
 
int arc_jtag_startup(struct arc_jtag *jtag_info)
{
    assert(jtag_info);
 
    arc_jtag_enque_reset_transaction(jtag_info);
 
    return jtag_execute_queue();
}
 
int arc_jtag_status(struct arc_jtag * const jtag_info, uint32_t * const value)
{
    uint8_t buffer[sizeof(uint32_t)];
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    /* Fill command queue. */
    arc_jtag_enque_reset_transaction(jtag_info);
    arc_jtag_enque_status_read(jtag_info, buffer);
    arc_jtag_enque_reset_transaction(jtag_info);
 
    /* Execute queue. */
    CHECK_RETVAL(jtag_execute_queue());
 
    /* Parse output. */
    *value = buf_get_u32(buffer, 0, 32);
 
    return ERROR_OK;
}
/* Helper function: Adding read/write register operation to queue */
static void arc_jtag_enque_register_rw(struct arc_jtag *jtag_info, uint32_t *addr,
    uint8_t *read_buffer, const uint32_t *write_buffer, uint32_t count)
{
    uint32_t i;
 
    for (i = 0; i < count; i++) {
        /* ARC jtag has optimization which is to increment ADDRESS_REG performing
         * each transaction. Making sequential reads/writes we can set address for
         * only first register in sequence, and than do read/write in cycle. */
        if (i == 0 || (addr[i] != addr[i-1] + 1)) {
            arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_ADDRESS_REG);
            /* Going to TAP_IDLE state we initiate jtag transaction.
             * Reading data we must go to TAP_IDLE, because further
             * the data would be read. In case of write we go to TAP_DRPAUSE,
             * because we need to write data to Data register first. */
            if (write_buffer)
                arc_jtag_enque_write_dr(jtag_info, addr[i], TAP_DRPAUSE);
            else
                arc_jtag_enque_write_dr(jtag_info, addr[i], TAP_IDLE);
            arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_DATA_REG);
        }
        if (write_buffer)
            arc_jtag_enque_write_dr(jtag_info, *(write_buffer + i), TAP_IDLE);
        else
            arc_jtag_enque_read_dr(jtag_info, read_buffer + i * 4, TAP_IDLE);
    }
    /* To prevent pollution of next register due to optimization it is necessary *
     * to reset transaction */
    arc_jtag_enque_reset_transaction(jtag_info);
}
 
static int arc_jtag_write_registers(struct arc_jtag *jtag_info, uint32_t type,
    uint32_t *addr, uint32_t count, const uint32_t *buffer)
{
    LOG_DEBUG("Writing to %s registers: addr[0]=0x%" PRIx32 ";count=%" PRIu32
              ";buffer[0]=0x%08" PRIx32,
        (type == ARC_JTAG_CORE_REG ? "core" : "aux"), *addr, count, *buffer);
 
    if (!count) {
        LOG_ERROR("Trying to write 0 registers");
        return ERROR_FAIL;
    }
 
    arc_jtag_enque_reset_transaction(jtag_info);
 
    /* What registers are we writing to? */
    const uint32_t transaction = (type == ARC_JTAG_CORE_REG ?
            ARC_JTAG_WRITE_TO_CORE_REG : ARC_JTAG_WRITE_TO_AUX_REG);
    arc_jtag_enque_set_transaction(jtag_info, transaction, TAP_DRPAUSE);
 
    arc_jtag_enque_register_rw(jtag_info, addr, NULL, buffer, count);
 
    return jtag_execute_queue();
}
 
static int arc_jtag_read_registers(struct arc_jtag *jtag_info, uint32_t type,
        uint32_t *addr, uint32_t count, uint32_t *buffer)
{
    int retval;
    uint32_t i;
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    LOG_DEBUG("Reading %s registers: addr[0]=0x%" PRIx32 ";count=%" PRIu32,
        (type == ARC_JTAG_CORE_REG ? "core" : "aux"), *addr, count);
 
    if (!count) {
        LOG_ERROR("Trying to read 0 registers");
        return ERROR_FAIL;
    }
 
    arc_jtag_enque_reset_transaction(jtag_info);
 
    /* What type of registers we are reading? */
    const uint32_t transaction = (type == ARC_JTAG_CORE_REG ?
            ARC_JTAG_READ_FROM_CORE_REG : ARC_JTAG_READ_FROM_AUX_REG);
    arc_jtag_enque_set_transaction(jtag_info, transaction, TAP_DRPAUSE);
 
    uint8_t *data_buf = calloc(count * 4, sizeof(uint8_t));
 
    arc_jtag_enque_register_rw(jtag_info, addr, data_buf, NULL, count);
 
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("Failed to execute jtag queue: %d", retval);
        retval = ERROR_FAIL;
        goto exit;
    }
 
    /* Convert byte-buffers to host /presentation. */
    for (i = 0; i < count; i++)
        buffer[i] = buf_get_u32(data_buf + 4 * i, 0, 32);
 
    LOG_DEBUG("Read from register: buf[0]=0x%" PRIx32, buffer[0]);
 
exit:
    free(data_buf);
 
    return retval;
}
 
 
int arc_jtag_write_core_reg_one(struct arc_jtag *jtag_info, uint32_t addr,
    uint32_t value)
{
    return arc_jtag_write_core_reg(jtag_info, &addr, 1, &value);
}
 
int arc_jtag_write_core_reg(struct arc_jtag *jtag_info, uint32_t *addr,
    uint32_t count, const uint32_t *buffer)
{
    return arc_jtag_write_registers(jtag_info, ARC_JTAG_CORE_REG, addr, count,
            buffer);
}
 
int arc_jtag_read_core_reg_one(struct arc_jtag *jtag_info, uint32_t addr,
    uint32_t *value)
{
    return arc_jtag_read_core_reg(jtag_info, &addr, 1, value);
}
 
int arc_jtag_read_core_reg(struct arc_jtag *jtag_info, uint32_t *addr,
    uint32_t count, uint32_t *buffer)
{
    return arc_jtag_read_registers(jtag_info, ARC_JTAG_CORE_REG, addr, count,
            buffer);
}
 
int arc_jtag_write_aux_reg_one(struct arc_jtag *jtag_info, uint32_t addr,
    uint32_t value)
{
    return arc_jtag_write_aux_reg(jtag_info, &addr, 1, &value);
}
 
int arc_jtag_write_aux_reg(struct arc_jtag *jtag_info, uint32_t *addr,
    uint32_t count, const uint32_t *buffer)
{
    return arc_jtag_write_registers(jtag_info, ARC_JTAG_AUX_REG, addr, count,
            buffer);
}
 
int arc_jtag_read_aux_reg_one(struct arc_jtag *jtag_info, uint32_t addr,
    uint32_t *value)
{
    return arc_jtag_read_aux_reg(jtag_info, &addr, 1, value);
}
 
int arc_jtag_read_aux_reg(struct arc_jtag *jtag_info, uint32_t *addr,
    uint32_t count, uint32_t *buffer)
{
    return arc_jtag_read_registers(jtag_info, ARC_JTAG_AUX_REG, addr, count,
            buffer);
}
 
int arc_jtag_write_memory(struct arc_jtag *jtag_info, uint32_t addr,
        uint32_t count, const uint32_t *buffer)
{
    assert(jtag_info);
    assert(buffer);
 
    LOG_DEBUG("Writing to memory: addr=0x%08" PRIx32 ";count=%" PRIu32 ";buffer[0]=0x%08" PRIx32,
        addr, count, *buffer);
 
    /* No need to waste time on useless operations. */
    if (!count)
        return ERROR_OK;
 
    /* We do not know where we come from. */
    arc_jtag_enque_reset_transaction(jtag_info);
 
    /* We want to write to memory. */
    arc_jtag_enque_set_transaction(jtag_info, ARC_JTAG_WRITE_TO_MEMORY, TAP_DRPAUSE);
 
    /* Set target memory address of the first word. */
    arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_ADDRESS_REG);
    arc_jtag_enque_write_dr(jtag_info, addr, TAP_DRPAUSE);
 
    /* Start sending words. Address is auto-incremented on 4bytes by HW. */
    arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_DATA_REG);
 
    uint32_t i;
    for (i = 0; i < count; i++)
        arc_jtag_enque_write_dr(jtag_info, *(buffer + i), TAP_IDLE);
 
    return jtag_execute_queue();
}
 
int arc_jtag_read_memory(struct arc_jtag *jtag_info, uint32_t addr,
    uint32_t count, uint32_t *buffer, bool slow_memory)
{
    uint8_t *data_buf;
    uint32_t i;
    int retval = ERROR_OK;
 
 
    assert(jtag_info);
    assert(jtag_info->tap);
 
    LOG_DEBUG("Reading memory: addr=0x%" PRIx32 ";count=%" PRIu32 ";slow=%c",
        addr, count, slow_memory ? 'Y' : 'N');
 
    if (!count)
        return ERROR_OK;
 
    data_buf = calloc(count * 4, sizeof(uint8_t));
    arc_jtag_enque_reset_transaction(jtag_info);
 
    /* We are reading from memory. */
    arc_jtag_enque_set_transaction(jtag_info, ARC_JTAG_READ_FROM_MEMORY, TAP_DRPAUSE);
 
    /* Read data */
    for (i = 0; i < count; i++) {
        /* When several words are read at consequent addresses we can
         * rely on ARC JTAG auto-incrementing address. That means that
         * address can be set only once, for a first word. However it
         * has been noted that at least in some cases when reading from
         * DDR, JTAG returns 0 instead of a real value. To workaround
         * this issue we need to do totally non-required address
         * writes, which however resolve a problem by introducing
         * delay. See STAR 9000832538... */
        if (slow_memory || i == 0) {
            /* Set address */
            arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_ADDRESS_REG);
            arc_jtag_enque_write_dr(jtag_info, addr + i * 4, TAP_IDLE);
 
            arc_jtag_enque_write_ir(jtag_info, ARC_JTAG_DATA_REG);
        }
        arc_jtag_enque_read_dr(jtag_info, data_buf + i * 4, TAP_IDLE);
    }
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("Failed to execute jtag queue: %d", retval);
        retval = ERROR_FAIL;
        goto exit;
    }
 
    /* Convert byte-buffers to host presentation. */
    for (i = 0; i < count; i++)
        buffer[i] = buf_get_u32(data_buf + 4*i, 0, 32);
 
exit:
    free(data_buf);
 
    return retval;
}