155 lines
3.3 KiB
C
155 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/***************************************************************************
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* Copyright (C) 2008 by Øyvind Harboe *
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* oyvind.harboe@zylin.com *
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***************************************************************************/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <jtag/interface.h>
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#include "bitbang.h"
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#include "hello.h"
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/* my private tap controller state, which tracks state for calling code */
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static tap_state_t dummy_state = TAP_RESET;
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static int dummy_clock; /* edge detector */
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static int clock_count; /* count clocks in any stable state, only stable states */
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static uint32_t dummy_data;
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static bb_value_t dummy_read(void)
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{
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int data = 1 & dummy_data;
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dummy_data = (dummy_data >> 1) | (1 << 31);
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return data ? BB_HIGH : BB_LOW;
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}
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static int dummy_write(int tck, int tms, int tdi)
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{
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/* TAP standard: "state transitions occur on rising edge of clock" */
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if (tck != dummy_clock) {
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if (tck) {
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tap_state_t old_state = dummy_state;
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dummy_state = tap_state_transition(old_state, tms);
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if (old_state != dummy_state) {
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if (clock_count) {
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LOG_DEBUG("dummy_tap: %d stable clocks", clock_count);
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clock_count = 0;
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}
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LOG_DEBUG("dummy_tap: %s", tap_state_name(dummy_state));
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#if defined(DEBUG)
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if (dummy_state == TAP_DRCAPTURE)
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dummy_data = 0x01255043;
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#endif
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} else {
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/* this is a stable state clock edge, no change of state here,
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* simply increment clock_count for subsequent logging
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*/
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++clock_count;
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}
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}
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dummy_clock = tck;
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}
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return ERROR_OK;
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}
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static int dummy_reset(int trst, int srst)
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{
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dummy_clock = 0;
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if (trst || (srst && (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
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dummy_state = TAP_RESET;
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LOG_DEBUG("reset to: %s", tap_state_name(dummy_state));
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return ERROR_OK;
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}
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static int dummy_led(int on)
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{
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return ERROR_OK;
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}
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static struct bitbang_interface dummy_bitbang = {
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.read = &dummy_read,
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.write = &dummy_write,
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.blink = &dummy_led,
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};
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static int dummy_khz(int khz, int *jtag_speed)
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{
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if (khz == 0)
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*jtag_speed = 0;
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else
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*jtag_speed = 64000/khz;
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return ERROR_OK;
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}
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static int dummy_speed_div(int speed, int *khz)
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{
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if (speed == 0)
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*khz = 0;
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else
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*khz = 64000/speed;
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return ERROR_OK;
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}
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static int dummy_speed(int speed)
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{
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return ERROR_OK;
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}
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static int dummy_init(void)
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{
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bitbang_interface = &dummy_bitbang;
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return ERROR_OK;
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}
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static int dummy_quit(void)
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{
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return ERROR_OK;
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}
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static const struct command_registration dummy_command_handlers[] = {
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{
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.name = "dummy",
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.mode = COMMAND_ANY,
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.help = "dummy interface driver commands",
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.chain = hello_command_handlers,
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.usage = "",
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},
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COMMAND_REGISTRATION_DONE,
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};
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/* The dummy driver is used to easily check the code path
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* where the target is unresponsive.
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*/
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static struct jtag_interface dummy_interface = {
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.supported = DEBUG_CAP_TMS_SEQ,
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.execute_queue = &bitbang_execute_queue,
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};
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struct adapter_driver dummy_adapter_driver = {
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.name = "dummy",
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.transports = jtag_only,
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.commands = dummy_command_handlers,
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.init = &dummy_init,
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.quit = &dummy_quit,
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.reset = &dummy_reset,
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.speed = &dummy_speed,
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.khz = &dummy_khz,
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.speed_div = &dummy_speed_div,
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.jtag_ops = &dummy_interface,
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};
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