/***************************************************************************
 *   Copyright (C) 2007 by Juergen Stuber <juergen@jstuber.net>            *
 *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   Copyright (C) 2011 by Jean-Christophe PLAGNIOL-VIILARD                *
 *   plagnioj@jcrosoft.com                                                 *
 *                                                                         *
 *   Copyright (C) 2015 by Marc Schink                                     *
 *   openocd-dev@marcschink.de                                             *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdint.h>
#include <math.h>

#include <jtag/interface.h>
#include <jtag/swd.h>
#include <jtag/commands.h>

#include <libjaylink/libjaylink.h>

static struct jaylink_context *jayctx;
static struct jaylink_device_handle *devh;
static struct jaylink_connection conn;
static struct jaylink_connection connlist[JAYLINK_MAX_CONNECTIONS];
static enum jaylink_jtag_version jtag_command_version;
static uint8_t caps[JAYLINK_DEV_EXT_CAPS_SIZE];

static uint32_t serial_number;
static bool use_serial_number;
static uint8_t usb_address;
static bool use_usb_address;
static uint8_t iface = JAYLINK_TIF_JTAG;
static bool trace_enabled;

#define JLINK_MAX_SPEED			12000
#define JLINK_TAP_BUFFER_SIZE	2048

static unsigned int swd_buffer_size = JLINK_TAP_BUFFER_SIZE;

/* 256 byte non-volatile memory */
struct device_config {
	uint8_t	usb_address;
	/* 0ffset 0x01 to 0x03 */
	uint8_t	reserved_1[3];
	uint32_t target_power;
	/* 0ffset 0x08 to 0x1f */
	uint8_t reserved_2[24];
	/* IP only for J-Link Pro */
	uint8_t ip_address[4];
	uint8_t subnet_mask[4];
	/* 0ffset 0x28 to 0x2f */
	uint8_t reserved_3[8];
	uint8_t mac_address[6];
	/* 0ffset 0x36 to 0xff */
	uint8_t reserved_4[202];
} __attribute__ ((packed));

static struct device_config config;
static struct device_config tmp_config;

/* Queue command functions */
static void jlink_end_state(tap_state_t state);
static void jlink_state_move(void);
static void jlink_path_move(int num_states, tap_state_t *path);
static void jlink_runtest(int num_cycles);
static void jlink_scan(bool ir_scan, enum scan_type type, uint8_t *buffer,
		int scan_size, struct scan_command *command);
static void jlink_reset(int trst, int srst);
static int jlink_swd_run_queue(void);
static void jlink_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data, uint32_t ap_delay_clk);
static int jlink_swd_switch_seq(enum swd_special_seq seq);

/* J-Link tap buffer functions */
static void jlink_tap_init(void);
static int jlink_tap_execute(void);
static void jlink_tap_ensure_space(int scans, int bits);
static void jlink_tap_append_step(int tms, int tdi);
static void jlink_tap_append_scan(int length, uint8_t *buffer,
		struct scan_command *command);

static enum tap_state jlink_last_state = TAP_RESET;
static int queued_retval;

/***************************************************************************/
/* External interface implementation */

static void jlink_execute_runtest(struct jtag_command *cmd)
{
	DEBUG_JTAG_IO("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles,
		cmd->cmd.runtest->end_state);

	jlink_end_state(cmd->cmd.runtest->end_state);
	jlink_runtest(cmd->cmd.runtest->num_cycles);
}

static void jlink_execute_statemove(struct jtag_command *cmd)
{
	DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);

	jlink_end_state(cmd->cmd.statemove->end_state);
	jlink_state_move();
}

static void jlink_execute_pathmove(struct jtag_command *cmd)
{
	DEBUG_JTAG_IO("pathmove: %i states, end in %i",
		cmd->cmd.pathmove->num_states,
		cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);

	jlink_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
}

static void jlink_execute_scan(struct jtag_command *cmd)
{
	int scan_size;
	enum scan_type type;
	uint8_t *buffer;

	DEBUG_JTAG_IO("scan end in %s", tap_state_name(cmd->cmd.scan->end_state));

	jlink_end_state(cmd->cmd.scan->end_state);

	scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
	DEBUG_JTAG_IO("scan input, length = %d", scan_size);

	type = jtag_scan_type(cmd->cmd.scan);
	jlink_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
}

static void jlink_execute_reset(struct jtag_command *cmd)
{
	DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst,
		cmd->cmd.reset->srst);

	jlink_tap_execute();
	jlink_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
	jlink_tap_execute();
}

static void jlink_execute_sleep(struct jtag_command *cmd)
{
	DEBUG_JTAG_IO("sleep %" PRIi32 "", cmd->cmd.sleep->us);
	jlink_tap_execute();
	jtag_sleep(cmd->cmd.sleep->us);
}

static int jlink_execute_command(struct jtag_command *cmd)
{
	switch (cmd->type) {
		case JTAG_RUNTEST:
			jlink_execute_runtest(cmd);
			break;
		case JTAG_TLR_RESET:
			jlink_execute_statemove(cmd);
			break;
		case JTAG_PATHMOVE:
			jlink_execute_pathmove(cmd);
			break;
		case JTAG_SCAN:
			jlink_execute_scan(cmd);
			break;
		case JTAG_RESET:
			jlink_execute_reset(cmd);
			break;
		case JTAG_SLEEP:
			jlink_execute_sleep(cmd);
			break;
		default:
			LOG_ERROR("BUG: Unknown JTAG command type encountered.");
			return ERROR_JTAG_QUEUE_FAILED;
	}

	return ERROR_OK;
}

static int jlink_execute_queue(void)
{
	int ret;
	struct jtag_command *cmd = jtag_command_queue;

	while (cmd != NULL) {
		ret = jlink_execute_command(cmd);

		if (ret != ERROR_OK)
			return ret;

		cmd = cmd->next;
	}

	return jlink_tap_execute();
}

static int jlink_speed(int speed)
{
	int ret;
	uint32_t freq;
	uint16_t divider;
	int max_speed;

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_SPEEDS)) {
		ret = jaylink_get_speeds(devh, &freq, &divider);

		if (ret != JAYLINK_OK) {
			LOG_ERROR("jaylink_get_speeds() failed: %s.",
				jaylink_strerror_name(ret));
			return ERROR_JTAG_DEVICE_ERROR;
		}

		freq = freq / 1000;
		max_speed = freq / divider;
	} else {
		max_speed = JLINK_MAX_SPEED;
	}

	if (!speed) {
		if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_ADAPTIVE_CLOCKING)) {
			LOG_ERROR("Adaptive clocking is not supported by the device.");
			return ERROR_JTAG_NOT_IMPLEMENTED;
		}

		speed = JAYLINK_SPEED_ADAPTIVE_CLOCKING;
	} else if (speed > max_speed) {
		LOG_INFO("Reduced speed from %d kHz to %d kHz (maximum).", speed,
			max_speed);
		speed = max_speed;
	}

	ret = jaylink_set_speed(devh, speed);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_set_speed() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_JTAG_DEVICE_ERROR;
	}

	return ERROR_OK;
}

static int jlink_speed_div(int speed, int *khz)
{
	*khz = speed;

	return ERROR_OK;
}

static int jlink_khz(int khz, int *jtag_speed)
{
	*jtag_speed = khz;

	return ERROR_OK;
}

static bool read_device_config(struct device_config *cfg)
{
	int ret;

	ret = jaylink_read_raw_config(devh, (uint8_t *)cfg);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_read_raw_config() failed: %s.",
			jaylink_strerror_name(ret));
		return false;
	}

	if (cfg->usb_address == 0xff)
		cfg->usb_address = 0x00;

	if (cfg->target_power == 0xffffffff)
		cfg->target_power = 0;

	return true;
}

static int select_interface(void)
{
	int ret;
	uint32_t interfaces;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SELECT_TIF)) {
		if (iface != JAYLINK_TIF_JTAG) {
			LOG_ERROR("Device supports JTAG transport only.");
			return ERROR_JTAG_INIT_FAILED;
		}

		return ERROR_OK;
	}

	ret = jaylink_get_available_interfaces(devh, &interfaces);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_get_available_interfaces() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_JTAG_INIT_FAILED;
	}

	if (!(interfaces & (1 << iface))) {
		LOG_ERROR("Selected transport is not supported by the device.");
		return ERROR_JTAG_INIT_FAILED;
	}

	ret = jaylink_select_interface(devh, iface);

	if (ret < 0) {
		LOG_ERROR("jaylink_select_interface() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_JTAG_INIT_FAILED;
	}

	return ERROR_OK;
}

static int jlink_register(void)
{
	int ret;
	int i;
	bool handle_found;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_REGISTER))
		return ERROR_OK;

	ret = jaylink_register(devh, &conn, connlist, NULL, NULL);

	if (ret < 0) {
		LOG_ERROR("jaylink_register() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	handle_found = false;

	for (i = 0; i < ret; i++) {
		if (connlist[i].handle == conn.handle) {
			handle_found = true;
			break;
		}
	}

	if (!handle_found) {
		LOG_ERROR("Registration failed: maximum number of connections on the "
			"device reached.");
		return ERROR_FAIL;
	}

	return ERROR_OK;
}

/*
 * Adjust the SWD transaction buffer size depending on the free device internal
 * memory. This ensures that the SWD transactions sent to the device do not
 * exceed the internal memory of the device.
 */
static bool adjust_swd_buffer_size(void)
{
	int ret;
	uint32_t tmp;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_FREE_MEMORY))
		return true;

	ret = jaylink_get_free_memory(devh, &tmp);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_get_free_memory() failed: %s.",
			jaylink_strerror_name(ret));
		return false;
	}

	if (tmp < 143) {
		LOG_ERROR("Not enough free device internal memory: %u bytes.", tmp);
		return false;
	}

	tmp = MIN(JLINK_TAP_BUFFER_SIZE, (tmp - 16) / 2);

	if (tmp != swd_buffer_size) {
		swd_buffer_size = tmp;
		LOG_DEBUG("Adjusted SWD transaction buffer size to %u bytes.",
			swd_buffer_size);
	}

	return true;
}

static int jlink_init(void)
{
	int ret;
	struct jaylink_device **devs;
	unsigned int i;
	bool found_device;
	uint32_t tmp;
	char *firmware_version;
	struct jaylink_hardware_version hwver;
	struct jaylink_hardware_status hwstatus;

	ret = jaylink_init(&jayctx);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_init() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_JTAG_INIT_FAILED;
	}

	ret = jaylink_get_device_list(jayctx, &devs);

	if (ret < 0) {
		LOG_ERROR("jaylink_get_device_list() failed: %s.",
			jaylink_strerror_name(ret));
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	found_device = false;

	if (!use_serial_number && !use_usb_address)
		LOG_INFO("No device selected, using first device.");

	for (i = 0; devs[i]; i++) {
		jaylink_device_get_serial_number(devs[i], &tmp);
		ret = jaylink_device_get_usb_address(devs[i]);

		if (use_usb_address && usb_address != ret)
			continue;

		if (use_serial_number && tmp != serial_number)
			continue;

		ret = jaylink_open(devs[i], &devh);

		if (ret != JAYLINK_OK) {
			LOG_ERROR("Failed to open device: %s.", jaylink_strerror_name(ret));
			continue;
		}

		found_device = true;
		break;
	}

	jaylink_free_device_list(devs, 1);

	if (!found_device) {
		LOG_ERROR("No J-Link device found.");
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	/*
	 * Be careful with changing the following initialization sequence because
	 * some devices are known to be sensitive regarding the order.
	 */

	ret = jaylink_get_firmware_version(devh, &firmware_version);

	if (ret > 0) {
		LOG_INFO("%s", firmware_version);
		free(firmware_version);
	} else if (!ret) {
		LOG_WARNING("Device responds empty firmware version string.");
	} else {
		LOG_ERROR("jaylink_get_firmware_version() failed: %s.",
			jaylink_strerror_name(ret));
		jaylink_close(devh);
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	memset(caps, 0, JAYLINK_DEV_EXT_CAPS_SIZE);
	ret = jaylink_get_caps(devh, caps);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_get_caps() failed: %s.", jaylink_strerror_name(ret));
		jaylink_close(devh);
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_EXT_CAPS)) {
		ret = jaylink_get_extended_caps(devh, caps);

		if (ret != JAYLINK_OK) {
			LOG_ERROR("jaylink_get_extended_caps() failed:  %s.",
				jaylink_strerror_name(ret));
			jaylink_close(devh);
			jaylink_exit(jayctx);
			return ERROR_JTAG_INIT_FAILED;
		}
	}

	jtag_command_version = JAYLINK_JTAG_V2;

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_HW_VERSION)) {
		ret = jaylink_get_hardware_version(devh, &hwver);

		if (ret != JAYLINK_OK) {
			LOG_ERROR("Failed to retrieve hardware version: %s.",
				jaylink_strerror_name(ret));
			jaylink_close(devh);
			jaylink_exit(jayctx);
			return ERROR_JTAG_INIT_FAILED;
		}

		LOG_INFO("Hardware version: %u.%02u", hwver.major, hwver.minor);

		if (hwver.major >= 5)
			jtag_command_version = JAYLINK_JTAG_V3;
	}

	if (iface == JAYLINK_TIF_SWD) {
		/*
		 * Adjust the SWD transaction buffer size in case there is already
		 * allocated memory on the device. This happens for example if the
		 * memory for SWO capturing is still allocated because the software
		 * which used the device before has not been shut down properly.
		 */
		if (!adjust_swd_buffer_size()) {
			jaylink_close(devh);
			jaylink_exit(jayctx);
			return ERROR_JTAG_INIT_FAILED;
		}
	}

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		if (!read_device_config(&config)) {
			LOG_ERROR("Failed to read device configuration data.");
			jaylink_close(devh);
			jaylink_exit(jayctx);
			return ERROR_JTAG_INIT_FAILED;
		}

		memcpy(&tmp_config, &config, sizeof(struct device_config));
	}

	ret = jaylink_get_hardware_status(devh, &hwstatus);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_get_hardware_status() failed: %s.",
			jaylink_strerror_name(ret));
		jaylink_close(devh);
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	LOG_INFO("VTarget = %u.%03u V", hwstatus.target_voltage / 1000,
		hwstatus.target_voltage % 1000);

	conn.handle = 0;
	conn.pid = 0;
	conn.hid = 0;
	conn.iid = 0;
	conn.cid = 0;

	ret = jlink_register();

	if (ret != ERROR_OK) {
		jaylink_close(devh);
		jaylink_exit(jayctx);
		return ERROR_JTAG_INIT_FAILED;
	}

	ret = select_interface();

	if (ret != ERROR_OK) {
		jaylink_close(devh);
		jaylink_exit(jayctx);
		return ret;
	}

	jlink_reset(0, 0);
	jtag_sleep(3000);
	jlink_tap_init();

	jlink_speed(jtag_get_speed_khz());

	if (iface == JAYLINK_TIF_JTAG) {
		/*
		 * J-Link devices with firmware version v5 and v6 seems to have an issue
		 * if the first tap move is not divisible by 8, so we send a TLR on
		 * first power up.
		 */
		for (i = 0; i < 8; i++)
			jlink_tap_append_step(1, 0);

		jlink_tap_execute();
	}

	return ERROR_OK;
}

static int jlink_quit(void)
{
	int ret;

	if (trace_enabled) {
		ret = jaylink_swo_stop(devh);

		if (ret != JAYLINK_OK)
			LOG_ERROR("jaylink_swo_stop() failed: %s.",
				jaylink_strerror_name(ret));
	}

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_REGISTER)) {
		ret = jaylink_unregister(devh, &conn, connlist, NULL, NULL);

		if (ret < 0)
			LOG_ERROR("jaylink_unregister() failed: %s.",
				jaylink_strerror_name(ret));
	}

	jaylink_close(devh);
	jaylink_exit(jayctx);

	return ERROR_OK;
}

/***************************************************************************/
/* Queue command implementations */

static void jlink_end_state(tap_state_t state)
{
	if (tap_is_state_stable(state))
		tap_set_end_state(state);
	else {
		LOG_ERROR("BUG: %i is not a valid end state", state);
		exit(-1);
	}
}

/* Goes to the end state. */
static void jlink_state_move(void)
{
	int i;
	int tms = 0;
	uint8_t tms_scan;
	uint8_t tms_scan_bits;

	tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
	tms_scan_bits = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());

	for (i = 0; i < tms_scan_bits; i++) {
		tms = (tms_scan >> i) & 1;
		jlink_tap_append_step(tms, 0);
	}

	tap_set_state(tap_get_end_state());
}

static void jlink_path_move(int num_states, tap_state_t *path)
{
	int i;

	for (i = 0; i < num_states; i++) {
		if (path[i] == tap_state_transition(tap_get_state(), false))
			jlink_tap_append_step(0, 0);
		else if (path[i] == tap_state_transition(tap_get_state(), true))
			jlink_tap_append_step(1, 0);
		else {
			LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition.",
				tap_state_name(tap_get_state()), tap_state_name(path[i]));
			exit(-1);
		}

		tap_set_state(path[i]);
	}

	tap_set_end_state(tap_get_state());
}

static void jlink_runtest(int num_cycles)
{
	int i;

	tap_state_t saved_end_state = tap_get_end_state();

	jlink_tap_ensure_space(1, num_cycles + 16);

	/* Only do a state_move when we're not already in IDLE. */
	if (tap_get_state() != TAP_IDLE) {
		jlink_end_state(TAP_IDLE);
		jlink_state_move();
		/* num_cycles--; */
	}

	/* Execute num_cycles. */
	for (i = 0; i < num_cycles; i++)
		jlink_tap_append_step(0, 0);

	/* Finish in end_state. */
	jlink_end_state(saved_end_state);

	if (tap_get_state() != tap_get_end_state())
		jlink_state_move();
}

static void jlink_scan(bool ir_scan, enum scan_type type, uint8_t *buffer,
		int scan_size, struct scan_command *command)
{
	tap_state_t saved_end_state;

	jlink_tap_ensure_space(1, scan_size + 16);

	saved_end_state = tap_get_end_state();

	/* Move to appropriate scan state. */
	jlink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);

	/* Only move if we're not already there. */
	if (tap_get_state() != tap_get_end_state())
		jlink_state_move();

	jlink_end_state(saved_end_state);

	/* Scan. */
	jlink_tap_append_scan(scan_size, buffer, command);

	/* We are in Exit1, go to Pause. */
	jlink_tap_append_step(0, 0);

	tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);

	if (tap_get_state() != tap_get_end_state())
		jlink_state_move();
}

static void jlink_reset(int trst, int srst)
{
	LOG_DEBUG("TRST: %i, SRST: %i.", trst, srst);

	/* Signals are active low. */
	if (srst == 0)
		jaylink_set_reset(devh);

	if (srst == 1)
		jaylink_clear_reset(devh);

	if (trst == 1)
		jaylink_jtag_clear_trst(devh);

	if (trst == 0)
		jaylink_jtag_set_trst(devh);
}

COMMAND_HANDLER(jlink_usb_command)
{
	if (CMD_ARGC != 1) {
		command_print(CMD_CTX, "Need exactly one argument for jlink usb.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	if (sscanf(CMD_ARGV[0], "%" SCNd8, &usb_address) != 1) {
		command_print(CMD_CTX, "Invalid USB address: %s.", CMD_ARGV[0]);
		return ERROR_FAIL;
	}

	if (usb_address > JAYLINK_USB_ADDRESS_3) {
		command_print(CMD_CTX, "Invalid USB address: %s.", CMD_ARGV[0]);
		return ERROR_FAIL;
	}

	use_serial_number = false;
	use_usb_address = true;

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_serial_command)
{
	if (CMD_ARGC != 1) {
		command_print(CMD_CTX, "Need exactly one argument for jlink serial.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	if (sscanf(CMD_ARGV[0], "%" SCNd32, &serial_number) != 1) {
		command_print(CMD_CTX, "Invalid serial number: %s.", CMD_ARGV[0]);
		return ERROR_FAIL;
	}

	use_serial_number = true;
	use_usb_address = false;

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_hwstatus_command)
{
	int ret;
	struct jaylink_hardware_status status;

	ret = jaylink_get_hardware_status(devh, &status);

	if (ret != JAYLINK_OK) {
		command_print(CMD_CTX, "jaylink_get_hardware_status() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	command_print(CMD_CTX, "VTarget = %u.%03u V",
		status.target_voltage / 1000, status.target_voltage % 1000);

	command_print(CMD_CTX, "TCK = %u TDI = %u TDO = %u TMS = %u SRST = %u "
		"TRST = %u", status.tck, status.tdi, status.tdo, status.tms,
		status.tres, status.trst);

	if (status.target_voltage < 1500)
		command_print(CMD_CTX, "Target voltage too low. Check target power.");

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_free_memory_command)
{
	int ret;
	uint32_t tmp;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_FREE_MEMORY)) {
		command_print(CMD_CTX, "Retrieval of free memory is not supported by "
			"the device.");
		return ERROR_OK;
	}

	ret = jaylink_get_free_memory(devh, &tmp);

	if (ret != JAYLINK_OK) {
		command_print(CMD_CTX, "jaylink_get_free_memory() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	command_print(CMD_CTX, "Device has %u bytes of free memory.", tmp);

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_jlink_jtag_command)
{
	int tmp;
	int version;

	if (!CMD_ARGC) {
		switch (jtag_command_version) {
			case JAYLINK_JTAG_V2:
				version = 2;
				break;
			case JAYLINK_JTAG_V3:
				version = 3;
				break;
			default:
				return ERROR_FAIL;
		}

		command_print(CMD_CTX, "JTAG command version: %i", version);
	} else if (CMD_ARGC == 1) {
		if (sscanf(CMD_ARGV[0], "%i", &tmp) != 1) {
			command_print(CMD_CTX, "Invalid argument: %s.", CMD_ARGV[0]);
			return ERROR_COMMAND_SYNTAX_ERROR;
		}

		switch (tmp) {
			case 2:
				jtag_command_version = JAYLINK_JTAG_V2;
				break;
			case 3:
				jtag_command_version = JAYLINK_JTAG_V3;
				break;
			default:
				command_print(CMD_CTX, "Invalid argument: %s.", CMD_ARGV[0]);
				return ERROR_COMMAND_SYNTAX_ERROR;
		}
	} else {
		command_print(CMD_CTX, "Need exactly one argument for jlink jtag.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_target_power_command)
{
	int ret;
	int enable;

	if (CMD_ARGC != 1) {
		command_print(CMD_CTX, "Need exactly one argument for jlink "
			"targetpower.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SET_TARGET_POWER)) {
		command_print(CMD_CTX, "Target power supply is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!strcmp(CMD_ARGV[0], "on")) {
		enable = true;
	} else if (!strcmp(CMD_ARGV[0], "off")) {
		enable = false;
	} else {
		command_print(CMD_CTX, "Invalid argument: %s.", CMD_ARGV[0]);
		return ERROR_FAIL;
	}

	ret = jaylink_set_target_power(devh, enable);

	if (ret != JAYLINK_OK) {
		command_print(CMD_CTX, "jaylink_set_target_power() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	return ERROR_OK;
}

static void show_config_usb_address(struct command_context *ctx)
{
	if (config.usb_address != tmp_config.usb_address)
		command_print(ctx, "USB address: %u [%u]", config.usb_address,
			tmp_config.usb_address);
	else
		command_print(ctx, "USB address: %u", config.usb_address);
}

static void show_config_ip_address(struct command_context *ctx)
{
	if (!memcmp(config.ip_address, tmp_config.ip_address, 4))
		command_print(ctx, "IP address: %d.%d.%d.%d",
			config.ip_address[3], config.ip_address[2],
			config.ip_address[1], config.ip_address[0]);
	else
		command_print(ctx, "IP address: %d.%d.%d.%d [%d.%d.%d.%d]",
			config.ip_address[3], config.ip_address[2],
			config.ip_address[1], config.ip_address[0],
			tmp_config.ip_address[3], tmp_config.ip_address[2],
			tmp_config.ip_address[1], tmp_config.ip_address[0]);

	if (!memcmp(config.subnet_mask, tmp_config.subnet_mask, 4))
		command_print(ctx, "Subnet mask: %d.%d.%d.%d",
			config.subnet_mask[3], config.subnet_mask[2],
			config.subnet_mask[1], config.subnet_mask[0]);
	else
		command_print(ctx, "Subnet mask: %d.%d.%d.%d [%d.%d.%d.%d]",
			config.subnet_mask[3], config.subnet_mask[2],
			config.subnet_mask[1], config.subnet_mask[0],
			tmp_config.subnet_mask[3], tmp_config.subnet_mask[2],
			tmp_config.subnet_mask[1], tmp_config.subnet_mask[0]);
}

static void show_config_mac_address(struct command_context *ctx)
{
	if (!memcmp(config.mac_address, tmp_config.mac_address, 6))
		command_print(ctx, "MAC address: %.02x:%.02x:%.02x:%.02x:%.02x:%.02x",
			config.mac_address[5], config.mac_address[4],
			config.mac_address[3], config.mac_address[2],
			config.mac_address[1], config.mac_address[0]);
	else
		command_print(ctx, "MAC address: %.02x:%.02x:%.02x:%.02x:%.02x:%.02x "
			"[%.02x:%.02x:%.02x:%.02x:%.02x:%.02x]",
			config.mac_address[5], config.mac_address[4],
			config.mac_address[3], config.mac_address[2],
			config.mac_address[1], config.mac_address[0],
			tmp_config.mac_address[5], tmp_config.mac_address[4],
			tmp_config.mac_address[3], tmp_config.mac_address[2],
			tmp_config.mac_address[1], tmp_config.mac_address[0]);
}

static void show_config_target_power(struct command_context *ctx)
{
	const char *target_power;
	const char *current_target_power;

	if (!config.target_power)
		target_power = "off";
	else
		target_power = "on";

	if (!tmp_config.target_power)
		current_target_power = "off";
	else
		current_target_power = "on";

	if (config.target_power != tmp_config.target_power)
		command_print(ctx, "Target power supply: %s [%s]", target_power,
			current_target_power);
	else
		command_print(ctx, "Target power supply: %s", target_power);
}

static void show_config(struct command_context *ctx)
{
	command_print(ctx, "J-Link device configuration:");

	show_config_usb_address(ctx);

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_SET_TARGET_POWER))
		show_config_target_power(ctx);

	if (jaylink_has_cap(caps, JAYLINK_DEV_CAP_ETHERNET)) {
		show_config_ip_address(ctx);
		show_config_mac_address(ctx);
	}
}

static int poll_trace(uint8_t *buf, size_t *size)
{
	int ret;
	uint32_t length;

	length = *size;

	ret = jaylink_swo_read(devh, buf, &length);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_swo_read() failed: %s.", jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	*size = length;

	return ERROR_OK;
}

static uint32_t calculate_trace_buffer_size(void)
{
	int ret;
	uint32_t tmp;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_GET_FREE_MEMORY))
		return 0;

	ret = jaylink_get_free_memory(devh, &tmp);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_get_free_memory() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	if (tmp > 0x3fff || tmp <= 0x600)
		tmp = tmp >> 1;
	else
		tmp = tmp - 0x400;

	return tmp & 0xffffff00;
}

static bool check_trace_freq(uint32_t freq, uint32_t divider, uint32_t trace_freq)
{
	double min;
	double deviation;

	min = fabs(1.0 - (freq / ((double)trace_freq * divider)));

	while (freq / divider > 0) {
		deviation = fabs(1.0 - (freq / ((double)trace_freq * divider)));

		if (deviation < 0.03) {
			LOG_DEBUG("Found suitable frequency divider %u with deviation of "
				"%.02f %%.", divider, deviation);
			return true;
		}

		if (deviation < min)
			min = deviation;

		divider++;
	}

	LOG_ERROR("Selected trace frequency is not supported by the device. "
		"Please choose a different trace frequency.");
	LOG_ERROR("Maximum permitted deviation is 3.00 %%, but only %.02f %% "
		"could be achieved.", min * 100);

	return false;
}

static int config_trace(bool enabled, enum tpio_pin_protocol pin_protocol,
		uint32_t port_size, unsigned int *trace_freq)
{
	int ret;
	uint32_t buffer_size;
	uint32_t freq;
	uint32_t divider;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SWO)) {
		LOG_ERROR("Trace capturing is not supported by the device.");
		return ERROR_FAIL;
	}

	if (pin_protocol != ASYNC_UART) {
		LOG_ERROR("Selected pin protocol is not supported.");
		return ERROR_FAIL;
	}

	trace_enabled = enabled;

	ret = jaylink_swo_stop(devh);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_swo_stop() failed: %s.", jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	if (!enabled) {
		/*
		 * Adjust the SWD transaction buffer size as stopping SWO capturing
		 * deallocates device internal memory.
		 */
		if (!adjust_swd_buffer_size())
			return ERROR_FAIL;

		return ERROR_OK;
	}

	buffer_size = calculate_trace_buffer_size();

	if (!buffer_size) {
		LOG_ERROR("Not enough free device memory to start trace capturing.");
		return ERROR_FAIL;
	}

	ret = jaylink_swo_get_speeds(devh, JAYLINK_SWO_MODE_UART, &freq, &divider);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_swo_get_speeds() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	if (!*trace_freq)
		*trace_freq = freq / divider;

	if (!check_trace_freq(freq, divider, *trace_freq))
		return ERROR_FAIL;

	LOG_DEBUG("Using %u bytes device memory for trace capturing.", buffer_size);

	ret = jaylink_swo_start(devh, JAYLINK_SWO_MODE_UART, *trace_freq,
		buffer_size);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_start_swo() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	/*
	 * Adjust the SWD transaction buffer size as starting SWO capturing
	 * allocates device internal memory.
	 */
	if (!adjust_swd_buffer_size())
		return ERROR_FAIL;

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_config_usb_address_command)
{
	uint8_t tmp;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Reading configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!CMD_ARGC) {
		show_config_usb_address(CMD_CTX);
	} else if (CMD_ARGC == 1) {
		if (sscanf(CMD_ARGV[0], "%" SCNd8, &tmp) != 1) {
			command_print(CMD_CTX, "Invalid USB address: %s.", CMD_ARGV[0]);
			return ERROR_FAIL;
		}

		if (tmp > JAYLINK_USB_ADDRESS_3) {
			command_print(CMD_CTX, "Invalid USB address: %u.", tmp);
			return ERROR_FAIL;
		}

		tmp_config.usb_address = tmp;
	} else {
		command_print(CMD_CTX, "Need exactly one argument for jlink config "
			"usb.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_config_target_power_command)
{
	int enable;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Reading configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SET_TARGET_POWER)) {
		command_print(CMD_CTX, "Target power supply is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!CMD_ARGC) {
		show_config_target_power(CMD_CTX);
	} else if (CMD_ARGC == 1) {
		if (!strcmp(CMD_ARGV[0], "on")) {
			enable = true;
		} else if (!strcmp(CMD_ARGV[0], "off")) {
			enable = false;
		} else {
			command_print(CMD_CTX, "Invalid argument: %s.", CMD_ARGV[0]);
			return ERROR_FAIL;
		}

		tmp_config.target_power = enable;
	} else {
		command_print(CMD_CTX, "Need exactly one argument for jlink config "
			"targetpower.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_config_mac_address_command)
{
	uint8_t addr[6];
	int i;
	char *e;
	const char *str;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Reading configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_ETHERNET)) {
		command_print(CMD_CTX, "Ethernet connectivity is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!CMD_ARGC) {
		show_config_mac_address(CMD_CTX);
	} else if (CMD_ARGC == 1) {
		str = CMD_ARGV[0];

		if ((strlen(str) != 17) || (str[2] != ':' || str[5] != ':' || \
				str[8] != ':' || str[11] != ':' || str[14] != ':')) {
			command_print(CMD_CTX, "Invalid MAC address format.");
			return ERROR_COMMAND_SYNTAX_ERROR;
		}

		for (i = 5; i >= 0; i--) {
			addr[i] = strtoul(str, &e, 16);
			str = e + 1;
		}

		if (!(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5])) {
			command_print(CMD_CTX, "Invalid MAC address: zero address.");
			return ERROR_COMMAND_SYNTAX_ERROR;
		}

		if (!(0x01 & addr[0])) {
			command_print(CMD_CTX, "Invalid MAC address: multicast address.");
			return ERROR_COMMAND_SYNTAX_ERROR;
		}

		memcpy(tmp_config.mac_address, addr, sizeof(addr));
	} else {
		command_print(CMD_CTX, "Need exactly one argument for jlink config "
			" mac.");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	return ERROR_OK;
}

static bool string_to_ip(const char *s, uint8_t *ip, int *pos)
{
	uint8_t lip[4];
	char *e;
	const char *s_save = s;
	int i;

	if (!s)
		return false;

	for (i = 0; i < 4; i++) {
		lip[i] = strtoul(s, &e, 10);

		if (*e != '.' && i != 3)
			return false;

		s = e + 1;
	}

	*pos = e - s_save;
	memcpy(ip, lip, sizeof(lip));

	return true;
}

static void cpy_ip(uint8_t *dst, uint8_t *src)
{
	int i, j;

	for (i = 0, j = 3; i < 4; i++, j--)
		dst[i] = src[j];
}

COMMAND_HANDLER(jlink_handle_config_ip_address_command)
{
	uint8_t ip_address[4];
	uint32_t subnet_mask = 0;
	int i, len;
	uint8_t subnet_bits = 24;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Reading configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_ETHERNET)) {
		command_print(CMD_CTX, "Ethernet connectivity is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!CMD_ARGC) {
		show_config_ip_address(CMD_CTX);
	} else {
		if (!string_to_ip(CMD_ARGV[0], ip_address, &i))
			return ERROR_COMMAND_SYNTAX_ERROR;

		len = strlen(CMD_ARGV[0]);

		/* Check for format A.B.C.D/E. */
		if (i < len) {
			if (CMD_ARGV[0][i] != '/')
				return ERROR_COMMAND_SYNTAX_ERROR;

			COMMAND_PARSE_NUMBER(u8, CMD_ARGV[0] + i + 1, subnet_bits);
		} else if (CMD_ARGC > 1) {
			if (!string_to_ip(CMD_ARGV[1], (uint8_t *)&subnet_mask, &i))
				return ERROR_COMMAND_SYNTAX_ERROR;
		}

		if (!subnet_mask)
			subnet_mask = (uint32_t)(subnet_bits < 32 ?
				((1ULL << subnet_bits) - 1) : 0xffffffff);

		cpy_ip(tmp_config.ip_address, ip_address);
		cpy_ip(tmp_config.subnet_mask, (uint8_t *)&subnet_mask);
	}

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_config_reset_command)
{
	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG))
		return ERROR_OK;

	memcpy(&tmp_config, &config, sizeof(struct device_config));

	return ERROR_OK;
}


COMMAND_HANDLER(jlink_handle_config_write_command)
{
	int ret;

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Reading configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_WRITE_CONFIG)) {
		command_print(CMD_CTX, "Writing configuration is not supported by the "
			"device.");
		return ERROR_OK;
	}

	if (!memcmp(&config, &tmp_config, sizeof(struct device_config))) {
		command_print(CMD_CTX, "Operation not performed due to no changes in "
			"the configuration.");
		return ERROR_OK;
	}

	ret = jaylink_write_raw_config(devh, (const uint8_t *)&tmp_config);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_write_raw_config() failed: %s.",
			jaylink_strerror_name(ret));
		return ERROR_FAIL;
	}

	if (!read_device_config(&config)) {
		LOG_ERROR("Failed to read device configuration for verification.");
		return ERROR_FAIL;
	}

	if (memcmp(&config, &tmp_config, sizeof(struct device_config))) {
		LOG_ERROR("Verification of device configuration failed. Please check "
			"your device.");
		return ERROR_FAIL;
	}

	memcpy(&tmp_config, &config, sizeof(struct device_config));
	command_print(CMD_CTX, "The new device configuration applies after power "
		"cycling the J-Link device.");

	return ERROR_OK;
}

COMMAND_HANDLER(jlink_handle_config_command)
{
	if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_READ_CONFIG)) {
		command_print(CMD_CTX, "Device doesn't support reading configuration.");
		return ERROR_OK;
	}

	if (CMD_ARGC == 0)
		show_config(CMD_CTX);

	return ERROR_OK;
}

static const struct command_registration jlink_config_subcommand_handlers[] = {
	{
		.name = "usb",
		.handler = &jlink_handle_config_usb_address_command,
		.mode = COMMAND_EXEC,
		.help = "set the USB address",
		.usage = "[0-3]",
	},
	{
		.name = "targetpower",
		.handler = &jlink_handle_config_target_power_command,
		.mode = COMMAND_EXEC,
		.help = "set the target power supply",
		.usage = "[on|off]"
	},
	{
		.name = "mac",
		.handler = &jlink_handle_config_mac_address_command,
		.mode = COMMAND_EXEC,
		.help = "set the MAC Address",
		.usage = "[ff:ff:ff:ff:ff:ff]",
	},
	{
		.name = "ip",
		.handler = &jlink_handle_config_ip_address_command,
		.mode = COMMAND_EXEC,
		.help = "set the IP address, where A.B.C.D is the IP address, "
			"E the bit of the subnet mask, F.G.H.I the subnet mask",
		.usage = "[A.B.C.D[/E] [F.G.H.I]]",
	},
	{
		.name = "reset",
		.handler = &jlink_handle_config_reset_command,
		.mode = COMMAND_EXEC,
		.help = "undo configuration changes"
	},
	{
		.name = "write",
		.handler = &jlink_handle_config_write_command,
		.mode = COMMAND_EXEC,
		.help = "write configuration to the device"
	},
	COMMAND_REGISTRATION_DONE
};

static const struct command_registration jlink_subcommand_handlers[] = {
	{
		.name = "jtag",
		.handler = &jlink_handle_jlink_jtag_command,
		.mode = COMMAND_EXEC,
		.help = "select the JTAG command version",
		.usage = "[2|3]",
	},
	{
		.name = "targetpower",
		.handler = &jlink_handle_target_power_command,
		.mode = COMMAND_EXEC,
		.help = "set the target power supply",
		.usage = "<on|off>"
	},
	{
		.name = "freemem",
		.handler = &jlink_handle_free_memory_command,
		.mode = COMMAND_EXEC,
		.help = "show free device memory"
	},
	{
		.name = "hwstatus",
		.handler = &jlink_handle_hwstatus_command,
		.mode = COMMAND_EXEC,
		.help = "show the hardware status"
	},
	{
		.name = "usb",
		.handler = &jlink_usb_command,
		.mode = COMMAND_CONFIG,
		.help = "set the USB address of the device that should be used",
		.usage = "<0-3>"
	},
	{
		.name = "serial",
		.handler = &jlink_serial_command,
		.mode = COMMAND_CONFIG,
		.help = "set the serial number of the device that should be used",
		.usage = "<serial number>"
	},
	{
		.name = "config",
		.handler = &jlink_handle_config_command,
		.mode = COMMAND_EXEC,
		.help = "access the device configuration. If no argument is given "
			"this will show the device configuration",
		.chain = jlink_config_subcommand_handlers,
	},
	COMMAND_REGISTRATION_DONE
};

static const struct command_registration jlink_command_handlers[] = {
	{
		.name = "jlink",
		.mode = COMMAND_ANY,
		.help = "perform jlink management",
		.chain = jlink_subcommand_handlers,
	},
	COMMAND_REGISTRATION_DONE
};

static int jlink_swd_init(void)
{
	iface = JAYLINK_TIF_SWD;

	return ERROR_OK;
}

static void jlink_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk)
{
	assert(!(cmd & SWD_CMD_RnW));
	jlink_swd_queue_cmd(cmd, NULL, value, ap_delay_clk);
}

static void jlink_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay_clk)
{
	assert(cmd & SWD_CMD_RnW);
	jlink_swd_queue_cmd(cmd, value, 0, ap_delay_clk);
}

static int_least32_t jlink_swd_frequency(int_least32_t hz)
{
	if (hz > 0)
		jlink_speed(hz / 1000);

	return hz;
}

/***************************************************************************/
/* J-Link tap functions */

static unsigned tap_length;
/* In SWD mode use tms buffer for direction control */
static uint8_t tms_buffer[JLINK_TAP_BUFFER_SIZE];
static uint8_t tdi_buffer[JLINK_TAP_BUFFER_SIZE];
static uint8_t tdo_buffer[JLINK_TAP_BUFFER_SIZE];

struct pending_scan_result {
	int first; /* First bit position in tdo_buffer to read. */
	int length; /* Number of bits to read. */
	struct scan_command *command; /* Corresponding scan command. */
	void *buffer;
};

#define MAX_PENDING_SCAN_RESULTS 256

static int pending_scan_results_length;
static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];

static void jlink_tap_init(void)
{
	tap_length = 0;
	pending_scan_results_length = 0;
}

static void jlink_tap_ensure_space(int scans, int bits)
{
	int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
	int available_bits = JLINK_TAP_BUFFER_SIZE * 8 - tap_length - 32;

	if (scans > available_scans || bits > available_bits)
		jlink_tap_execute();
}

static void jlink_tap_append_step(int tms, int tdi)
{
	int index_var = tap_length / 8;

	assert(index_var < JLINK_TAP_BUFFER_SIZE);

	int bit_index = tap_length % 8;
	uint8_t bit = 1 << bit_index;

	/* We do not pad TMS, so be sure to initialize all bits. */
	if (0 == bit_index)
		tms_buffer[index_var] = tdi_buffer[index_var] = 0;

	if (tms)
		tms_buffer[index_var] |= bit;
	else
		tms_buffer[index_var] &= ~bit;

	if (tdi)
		tdi_buffer[index_var] |= bit;
	else
		tdi_buffer[index_var] &= ~bit;

	tap_length++;
}

static void jlink_tap_append_scan(int length, uint8_t *buffer,
		struct scan_command *command)
{
	struct pending_scan_result *pending_scan_result =
		&pending_scan_results_buffer[pending_scan_results_length];
	int i;

	pending_scan_result->first = tap_length;
	pending_scan_result->length = length;
	pending_scan_result->command = command;
	pending_scan_result->buffer = buffer;

	for (i = 0; i < length; i++) {
		int tms = (i < (length - 1)) ? 0 : 1;
		int tdi = (buffer[i / 8] & (1 << (i % 8))) != 0;
		jlink_tap_append_step(tms, tdi);
	}

	pending_scan_results_length++;
}

/*
 * Pad and send a tap sequence to the device, and receive the answer. For the
 * purpose of padding we assume that we are in idle or pause state.
 */
static int jlink_tap_execute(void)
{
	int i;
	int ret;

	if (!tap_length)
		return ERROR_OK;

	jlink_last_state = jtag_debug_state_machine(tms_buffer, tdi_buffer,
		tap_length, jlink_last_state);

	jlink_last_state = jtag_debug_state_machine(tms_buffer, tdi_buffer,
		tap_length, jlink_last_state);

	ret = jaylink_jtag_io(devh, tms_buffer, tdi_buffer, tdo_buffer,
		tap_length, jtag_command_version);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_jtag_io() failed: %s.", jaylink_strerror_name(ret));
		jlink_tap_init();
		return ERROR_JTAG_QUEUE_FAILED;
	}

	for (i = 0; i < pending_scan_results_length; i++) {
		struct pending_scan_result *pending_scan_result = &pending_scan_results_buffer[i];
		uint8_t *buffer = pending_scan_result->buffer;
		int length = pending_scan_result->length;
		int first = pending_scan_result->first;
		struct scan_command *command = pending_scan_result->command;

		/* Copy to buffer. */
		buf_set_buf(tdo_buffer, first, buffer, 0, length);

		DEBUG_JTAG_IO("Pending scan result, length = %d.", length);

		if (jtag_read_buffer(buffer, command) != ERROR_OK) {
			jlink_tap_init();
			return ERROR_JTAG_QUEUE_FAILED;
		}

		if (pending_scan_result->buffer != NULL)
			free(pending_scan_result->buffer);
	}

	jlink_tap_init();

	return ERROR_OK;
}

static void fill_buffer(uint8_t *buf, uint32_t val, uint32_t len)
{
	unsigned int tap_pos = tap_length;

	while (len > 32) {
		buf_set_u32(buf, tap_pos, 32, val);
		len -= 32;
		tap_pos += 32;
	}

	if (len)
		buf_set_u32(buf, tap_pos, len, val);
}

static void jlink_queue_data_out(const uint8_t *data, uint32_t len)
{
	const uint32_t dir_out = 0xffffffff;

	if (data)
		bit_copy(tdi_buffer, tap_length, data, 0, len);
	else
		fill_buffer(tdi_buffer, 0, len);

	fill_buffer(tms_buffer, dir_out, len);
	tap_length += len;
}

static void jlink_queue_data_in(uint32_t len)
{
	const uint32_t dir_in = 0;

	fill_buffer(tms_buffer, dir_in, len);
	tap_length += len;
}

static int jlink_swd_switch_seq(enum swd_special_seq seq)
{
	const uint8_t *s;
	unsigned int s_len;

	switch (seq) {
		case LINE_RESET:
			LOG_DEBUG("SWD line reset");
			s = swd_seq_line_reset;
			s_len = swd_seq_line_reset_len;
			break;
		case JTAG_TO_SWD:
			LOG_DEBUG("JTAG-to-SWD");
			s = swd_seq_jtag_to_swd;
			s_len = swd_seq_jtag_to_swd_len;
			break;
		case SWD_TO_JTAG:
			LOG_DEBUG("SWD-to-JTAG");
			s = swd_seq_swd_to_jtag;
			s_len = swd_seq_swd_to_jtag_len;
			break;
		default:
			LOG_ERROR("Sequence %d not supported.", seq);
			return ERROR_FAIL;
	}

	jlink_queue_data_out(s, s_len);

	return ERROR_OK;
}

static int jlink_swd_run_queue(void)
{
	int i;
	int ret;

	LOG_DEBUG("Executing %d queued transactions.", pending_scan_results_length);

	if (queued_retval != ERROR_OK) {
		LOG_DEBUG("Skipping due to previous errors: %d.", queued_retval);
		goto skip;
	}

	/*
	 * A transaction must be followed by another transaction or at least 8 idle
	 * cycles to ensure that data is clocked through the AP.
	 */
	jlink_queue_data_out(NULL, 8);

	ret = jaylink_swd_io(devh, tms_buffer, tdi_buffer, tdo_buffer, tap_length);

	if (ret != JAYLINK_OK) {
		LOG_ERROR("jaylink_swd_io() failed: %s.", jaylink_strerror_name(ret));
		goto skip;
	}

	for (i = 0; i < pending_scan_results_length; i++) {
		int ack = buf_get_u32(tdo_buffer, pending_scan_results_buffer[i].first, 3);

		if (ack != SWD_ACK_OK) {
			LOG_DEBUG("SWD ack not OK: %d %s", ack,
				  ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK");
			queued_retval = ack == SWD_ACK_WAIT ? ERROR_WAIT : ERROR_FAIL;
			goto skip;
		} else if (pending_scan_results_buffer[i].length) {
			uint32_t data = buf_get_u32(tdo_buffer, 3 + pending_scan_results_buffer[i].first, 32);
			int parity = buf_get_u32(tdo_buffer, 3 + 32 + pending_scan_results_buffer[i].first, 1);

			if (parity != parity_u32(data)) {
				LOG_ERROR("SWD: Read data parity mismatch.");
				queued_retval = ERROR_FAIL;
				goto skip;
			}

			if (pending_scan_results_buffer[i].buffer)
				*(uint32_t *)pending_scan_results_buffer[i].buffer = data;
		}
	}

skip:
	jlink_tap_init();
	ret = queued_retval;
	queued_retval = ERROR_OK;

	return ret;
}

static void jlink_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data, uint32_t ap_delay_clk)
{
	uint8_t data_parity_trn[DIV_ROUND_UP(32 + 1, 8)];
	if (tap_length + 46 + 8 + ap_delay_clk >= sizeof(tdi_buffer) * 8 ||
	    pending_scan_results_length == MAX_PENDING_SCAN_RESULTS) {
		/* Not enough room in the queue. Run the queue. */
		queued_retval = jlink_swd_run_queue();
	}

	if (queued_retval != ERROR_OK)
		return;

	cmd |= SWD_CMD_START | SWD_CMD_PARK;

	jlink_queue_data_out(&cmd, 8);

	pending_scan_results_buffer[pending_scan_results_length].first = tap_length;

	if (cmd & SWD_CMD_RnW) {
		/* Queue a read transaction. */
		pending_scan_results_buffer[pending_scan_results_length].length = 32;
		pending_scan_results_buffer[pending_scan_results_length].buffer = dst;

		jlink_queue_data_in(1 + 3 + 32 + 1 + 1);
	} else {
		/* Queue a write transaction. */
		pending_scan_results_buffer[pending_scan_results_length].length = 0;
		jlink_queue_data_in(1 + 3 + 1);

		buf_set_u32(data_parity_trn, 0, 32, data);
		buf_set_u32(data_parity_trn, 32, 1, parity_u32(data));

		jlink_queue_data_out(data_parity_trn, 32 + 1);
	}

	pending_scan_results_length++;

	/* Insert idle cycles after AP accesses to avoid WAIT. */
	if (cmd & SWD_CMD_APnDP)
		jlink_queue_data_out(NULL, ap_delay_clk);
}

static const struct swd_driver jlink_swd = {
	.init = &jlink_swd_init,
	.frequency = &jlink_swd_frequency,
	.switch_seq = &jlink_swd_switch_seq,
	.read_reg = &jlink_swd_read_reg,
	.write_reg = &jlink_swd_write_reg,
	.run = &jlink_swd_run_queue,
};

static const char * const jlink_transports[] = { "jtag", "swd", NULL };

struct jtag_interface jlink_interface = {
	.name = "jlink",
	.commands = jlink_command_handlers,
	.transports = jlink_transports,
	.swd = &jlink_swd,
	.execute_queue = &jlink_execute_queue,
	.speed = &jlink_speed,
	.speed_div = &jlink_speed_div,
	.khz = &jlink_khz,
	.init = &jlink_init,
	.quit = &jlink_quit,
	.config_trace = &config_trace,
	.poll_trace = &poll_trace,
};