/* MSPDebug - debugging tool for MSP430 MCUs
 * Copyright (C) 2021 sys64738@disroot.org
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <stddef.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#include "util.h"
#include "output.h"
#include "ctrlc.h"
#include "jtaglib.h"
#include "mehfet_proto.h"
#include "mehfet_xport.h"

#include "mehfet.h"


struct mehfet_device {
	struct jtdev jtag;
	transport_t trans;
	enum mehfet_conn connstat;
};


/*extern void __builtin_trap(void);*/
#define NO_LL_JTAG_BP 0
#define no_ll_jtag() \
	do { \
		printc_err("mehfet: %s: low-lewel JTAG function not implemented!\n", __func__); \
		p->failed = 1; \
		if (NO_LL_JTAG_BP) /*__builtin_trap()*/; \
	} while (0) \


#define JTMF_GET_DEV(p) ((struct mehfet_device*)((size_t)(p) - \
			offsetof(struct mehfet_device, jtag))) \


static int jtmf_open(struct jtdev* p, const char* device)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
	return -1;
}
static void jtmf_close(struct jtdev* p)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
}
static void jtmf_power_on(struct jtdev* p)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
}
static void jtmf_power_off(struct jtdev* p)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
}
static void jtmf_connect(struct jtdev* p)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
}
static void jtmf_release(struct jtdev* p)
{
	printc_err("mehfet: %s should not get called.\n", __func__);
	p->failed = 1;
}

static void jtmf_tck(struct jtdev* p, int _) { (void)_; no_ll_jtag(); }
static void jtmf_tms(struct jtdev* p, int _) { (void)_; no_ll_jtag(); }
static void jtmf_tdi(struct jtdev* p, int _) { (void)_; no_ll_jtag(); }
static void jtmf_rst(struct jtdev* p, int _) { (void)_; no_ll_jtag(); }
static void jtmf_tst(struct jtdev* p, int _) { (void)_; no_ll_jtag(); }
static int jtmf_tdo_get(struct jtdev* p) { no_ll_jtag(); return 0; }

static void jtmf_tclk(struct jtdev* p, int out)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	int r = mehfet_cmd_tclk_edge(d->trans, out);
	if (r < 0) p->failed = 1;
}
static int jtmf_tclk_get(struct jtdev* p)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);
	int ret = 1;

	enum mehfet_lines lines = 0;
	int r = mehfet_cmd_get_old_lines(d->trans, &lines);
	if (r < 0) {
		p->failed = 1;
	} else {
		ret = (lines & mehfet_line_tclk) ? 1 : 0;
	}

	return ret;
}
static void jtmf_tclk_strobe(struct jtdev* p, unsigned int count)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	int r = mehfet_cmd_tclk_burst(d->trans, count);
	if (r < 0) p->failed = 1;
}

/* MehFET has no leds */
static void jtmf_led_green(struct jtdev* p, int out) { (void)p; (void)out; }
static void jtmf_led_red  (struct jtdev* p, int out) { (void)p; (void)out; }

static uint8_t jtmf_ir_shift(struct jtdev *p, uint8_t ir)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	uint8_t ret = 0;
	int r = mehfet_cmd_irshift(d->trans, ir, &ret);
	if (r < 0) p->failed = 1;

	return ret;
}
static uint8_t jtmf_dr_shift_8(struct jtdev *p, uint8_t dr)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	uint8_t ret = 0;
	int r = mehfet_cmd_drshift(d->trans, 8, &dr, &ret);
	if (r < 0) p->failed = 1;

	return ret;
}
static uint16_t jtmf_dr_shift_16(struct jtdev *p, uint16_t dr)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	uint8_t inbuf[2] = { dr & 0xff, (dr >> 8) & 0xff };
	uint8_t outbuf[2];
	int r = mehfet_cmd_drshift(d->trans, 16, inbuf, outbuf);
	if (r < 0) p->failed = 1;

	return outbuf[0] | ((uint16_t)outbuf[1] << 8);
}
static uint32_t jtmf_dr_shift_20(struct jtdev *p, uint32_t dr)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	uint8_t inbuf[3] = { dr & 0xff, (dr >> 8) & 0xff, (dr >> 16) & 0x0f };
	uint8_t outbuf[3];
	int r = mehfet_cmd_drshift(d->trans, 20, inbuf, outbuf);
	if (r < 0) p->failed = 1;

	return outbuf[0] | ((uint32_t)outbuf[1] << 8) | ((uint32_t)outbuf[2] << 16);
}
static void jtmf_tms_sequence(struct jtdev *p, int bits, unsigned int value)
{
	struct mehfet_device* d = JTMF_GET_DEV(p);

	enum mehfet_lines lines = 0;
	int r = mehfet_cmd_get_old_lines(d->trans, &lines);
	if (r < 0) {
		p->failed = 1;
		return;
	}

	uint8_t dbuf[4] = { value & 0xff, (value >> 8) & 0xff,
						(value >> 16) & 0xff, (value >> 24) & 0xff };
	r = mehfet_cmd_tms_seq(d->trans, lines & mehfet_line_tdi, bits, dbuf);
	if (r < 0) p->failed = 1;
}
static void jtmf_init_dap(struct jtdev *p)
{
	struct mehfet_device* dev = JTMF_GET_DEV(p);

	enum mehfet_resettap_status stat = 0;
	int r = mehfet_cmd_reset_tap(dev->trans, mehfet_rsttap_do_reset
			| mehfet_rsttap_fuse_do, &stat);

	if (r < 0) p->failed = 1;
}


static const struct jtdev_func jtdev_func_mehfet = {
	.jtdev_open        = jtmf_open,
	.jtdev_close       = jtmf_close,
	.jtdev_power_on    = jtmf_power_on,
	.jtdev_power_off   = jtmf_power_off,
	.jtdev_connect     = jtmf_connect,
	.jtdev_release     = jtmf_release,
	.jtdev_tck         = jtmf_tck,
	.jtdev_tms         = jtmf_tms,
	.jtdev_tdi         = jtmf_tdi,
	.jtdev_rst         = jtmf_rst,
	.jtdev_tst         = jtmf_tst,
	.jtdev_tdo_get     = jtmf_tdo_get,
	.jtdev_tclk        = jtmf_tclk,
	.jtdev_tclk_get    = jtmf_tclk_get,
	.jtdev_tclk_strobe = jtmf_tclk_strobe,
	.jtdev_led_green   = jtmf_led_green,
	.jtdev_led_red     = jtmf_led_red,

	.jtdev_ir_shift    = jtmf_ir_shift,
	.jtdev_dr_shift_8  = jtmf_dr_shift_8,
	.jtdev_dr_shift_16 = jtmf_dr_shift_16,
	.jtdev_dr_shift_20 = jtmf_dr_shift_20,
	.jtdev_tms_sequence= jtmf_tms_sequence,
	.jtdev_init_dap    = jtmf_init_dap
};


/*---------------------------------------------------------------------------*/

static int check_dev_ok(struct mehfet_device* dev, const struct device_args* args,
		enum mehfet_conn* useconn) {
	transport_t t = dev->trans;
	struct mehfet_info info;
	int r;

	r = mehfet_cmd_info(t, &info);
	if (r < 0) return r;

	printc_dbg("mehfet: MehFET %s\n", info.devicename);
	free(info.devicename);

	if (info.proto_version < MEHFET_PROTO_VER_MIN_SUPPORTED) {
		printc_err("mehfet: device has protocol version %04x, "
				"need at least %04x\n", info.proto_version,
				MEHFET_PROTO_VER_MIN_SUPPORTED);
		return -1;
	}
	if (info.proto_version > MEHFET_PROTO_VER) {
		printc_err("mehfet: device has newer protocol version %04x "
				"supporting at most %04x\n", info.proto_version,
				MEHFET_PROTO_VER);
		return -1;
	}

	if (args->flags & DEVICE_FLAG_JTAG) {
		if (!(info.caps & (mehfet_cap_jtag_noentry | mehfet_cap_jtag_entryseq))) {
			printc_err("mehfet: Cannot do JTAG, device doesn't have the capability\n");
			return -1;
		}

		// devices that don't need one will probably work when given an entry
		// sequence. no good way of doing a proper autodetect sadly
		if (info.caps & mehfet_cap_jtag_entryseq)
			*useconn = mehfet_conn_jtag_entryseq;
		else
			*useconn = mehfet_conn_jtag_noentry;
	} else {
		if (!(info.caps & mehfet_cap_sbw_entryseq)) {
			printc_err("mehfet: Cannot do Spy-Bi-Wire, device doesn't have the capability\n");
			return -1;
		}
		*useconn = mehfet_conn_sbw_entryseq;
	}

	if (args->flags & DEVICE_FLAG_FORCE_RESET)
		*useconn |= mehfet_conn_nrstmask;

	mehfet_transport_set_buf_size(t, (int)info.packet_buf_size);

	return 0;
}

static void mehfet_destroy(device_t dev_base) {
	struct mehfet_device* dev = (struct mehfet_device*)dev_base;

	if (!dev) return;

#ifdef DEBUG_MEHFET_DRIVER
	printc_dbg("mehfet: releasing device & disconnecting\n");
#endif

	if (dev->trans) {
		jtag_release_device(&dev->jtag, 0xfffe); // 0xfffe=reset address : POR

		mehfet_cmd_disconnect(dev->trans);

		dev->trans->ops->destroy(dev->trans);
		dev->trans = NULL;
	}

	free(dev);
}

static device_t mehfet_open(const struct device_args* args) {
	struct mehfet_device* dev;
	int r;

	if ((args->flags & DEVICE_FLAG_TTY)) {
		printc_err("mehfet: this driver does not support TTY access\n");
		return NULL;
	}

	dev = calloc(1, sizeof(*dev));
	if (!dev) {
		printc_err("mehfet: malloc: %s\n", last_error());
		return NULL;
	}

	dev->jtag.base.type = &device_mehfet;
	dev->jtag.base.max_breakpoints = 2; // TODO
	dev->jtag.base.need_probe = 1; // TODO
	dev->jtag.f = &jtdev_func_mehfet;

	// the MehFET currently doesn't have a designated PID, so we can't really
	// default to one.
	dev->trans = mehfet_transport_open(args->path,
			((args->flags & DEVICE_FLAG_HAS_VID_PID) ? &args->vid : NULL),
			((args->flags & DEVICE_FLAG_HAS_VID_PID) ? &args->pid : NULL),
			args->requested_serial);
	if (!dev->trans) goto FAIL;

	enum mehfet_conn useconn;
	r = check_dev_ok(dev, args, &useconn);
	if (r < 0) goto FAIL;

	r = mehfet_cmd_connect(dev->trans, useconn);
	if (r < 0) goto FAIL;

	r = mehfet_cmd_status(dev->trans, &dev->connstat);
	if (r < 0) goto FAIL;

	if (dev->connstat != (useconn & mehfet_conn_typemask)) {
		printc_err("mehfet: could not create connection to device\n");
		goto FAIL;
	}

	r = jtag_dev_init(&dev->jtag);
	if (r < 0) goto FAIL;

	// JTAG fuse check has been performed, so we can now switch to a
	// higher-speed physical transport suitable for ~350 kHz TCLK strobes used
	// in (and required for) flash programming
	r = mehfet_cmd_set_clkspeed(dev->trans, true);
	if (r < 0) goto FAIL;

#ifdef DEBUG_MEHFET_DRIVER
	printc_dbg("mehfet: device opened\n");
#endif

	return (device_t)dev;

FAIL:
	mehfet_destroy((device_t)dev);
	return NULL;
}

const struct device_class device_mehfet = {
	.name = "mehfet",
	.help = "MehFET USB JTAG/SBW device",
	.open     = mehfet_open,
	.destroy  = mehfet_destroy,
	.readmem  = jtag_dev_readmem,
	.writemem = jtag_dev_writemem,
	.getregs  = jtag_dev_getregs,
	.setregs  = jtag_dev_setregs,
	.ctl      = jtag_dev_ctl,
	.poll     = jtag_dev_poll,
	.erase    = jtag_dev_erase,
	.getconfigfuses = jtag_dev_getconfigfuses
};