/*
 * lpc111x-isp/lpc111x.c - LPC111x/LPC11Cxx ISP programmer
 *
 * Written 2012 by Werner Almesberger
 * Copyright 2012 Werner Almesberger
 *
 * 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.
 */


#define	_GNU_SOURCE	/* for vasprintf */
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <alloca.h>

#include <ubb/ubb.h>
#include <ubb/swuart.h>


#define	TGT_nRESET	UBB_CMD
#define	TGT_nISP	UBB_DAT1
#define	TGT_TX		UBB_DAT3
#define	TGT_RX		UBB_DAT2

#define	HOST_RX		TGT_TX
#define	HOST_TX		TGT_RX

#define	MAX_BUF		10000
#define	AUTOBAUD_TRIES	10
#define	SYNC		"Synchronized"

static int verbose = 0;
static int quiet = 0;


/* ----- Debugging and tracing --------------------------------------------- */


static void trace(const char *label, const uint8_t *s, int len)
{
	const uint8_t *end = s+len;

	if (label)
		printf("%s ", label);
	for (end = s+len; s != end; s++) {
		if (*s >= ' ' && *s <= '~')
			printf("%c", *s);
		else if (*s == 10)
			printf("\\n");
		else if (*s == 13)
			printf("\\r");
		else
			printf("\\%02o", *s);
	}
	printf("\n");
}


static void trace_out(const void *s, int len)
{
	trace(">>>", s, len);
}


static void trace_in(const void *s, int len)
{
	trace("<<<", s, len);
}


/* ----- Dialog functions -------------------------------------------------- */


static const char *dialog_fixed(int idle, const char *msg)
{
	static char *res = NULL;
	int msg_len = strlen(msg);
	char *tx_buf = alloca(msg_len+3);
	char *rx_buf = alloca(MAX_BUF);
	char *s, *t;
	int got;

	memcpy(tx_buf, msg, msg_len);
	memcpy(tx_buf+msg_len, "\r\n", 2);

	if (verbose)
		trace_out(tx_buf, msg_len+2);
	got = swuart_trx(tx_buf, msg_len+2, rx_buf, MAX_BUF, idle, idle);
	if (verbose)
		trace_in(rx_buf, got);

	if (got < msg_len+2) {
		fprintf(stderr, "response too short for echo\n");
		exit(1);
	}
	if (memcmp(rx_buf, msg, msg_len) ||
	    rx_buf[msg_len] != '\r' || rx_buf[msg_len+1] != '\n') {
		fprintf(stderr, "echo mismatch\n");
		exit(1);
	}

	if (memchr(rx_buf, 0, got)) {
		fprintf(stderr, "NUL in response\n");
		exit(1);
	}

	rx_buf += msg_len+2;
	got -= msg_len+2;

	res = realloc(res, got+1);
	if (!res) {
		perror("realloc");
		exit(1);
	}

	t = res;
	for (s = rx_buf; s != rx_buf+got; s++) {
		if (*s == '\r') {
			if (s+1 != rx_buf+got && s[1] == '\n')
				continue;
			fprintf(stderr, "\\r without \\n\n");
			exit(1);
		}
		if (*s == '\n' && !s[1])
			break;
		*t++ = *s;
	}
	*t = 0;

	return res;
}


static const char *vdialog(int idle, const char *cmd, va_list ap)
{
	char *msg;

	vasprintf(&msg, cmd, ap);
	return dialog_fixed(idle, msg);
}


static const char *dialog(int idle, const char *cmd, ...)
{
	va_list ap;
	const char *res;

	va_start(ap, cmd);
	res = vdialog(idle, cmd, ap);
	va_end(ap);
	return res;
}


static const char *dialog_rc(int idle, const char *cmd, ...)
{
	va_list ap;
	const char *res, *p;
	unsigned  rc;

	va_start(ap, cmd);
	res = vdialog(idle, cmd, ap);
	va_end(ap);

	p = strchr(res, '\n');
	if (!p || sscanf(res, "%u", &rc) != 1) {
		fprintf(stderr, "invalid status\n");
		exit(1);
	}

	if (rc != 0) {
		fprintf(stderr, "rc %d\n", rc);
		exit(1);
	}

	return p+1;
}


static int autobaud(void)
{
	uint8_t reply[100];
	int i, got;
	const char *res;

	for (i = 0; i != AUTOBAUD_TRIES; i++) {
		CLR(TGT_nRESET);
		usleep(10);	/* DS Table 9 pg 29 says min 50 ns */
		SET(TGT_nRESET);

		usleep(5*1000);	/* UM 26.3.1 pg 408 says max 3 ms */

		got = swuart_trx("?", 1, reply, sizeof(reply), 1000, 100);
		if (got != strlen(SYNC)+2 || memcmp(reply, SYNC "\r\n", got))
			continue;

		res = dialog(100, SYNC);

		if (!strcmp(res, "OK"))
			return 1;
	}
	return 0;
}


/* ----- Devices database -------------------------------------------------- */


static const struct device {
	const char *name;
	unsigned id;
	int flash_kb;
} devices[] = {
	{ "LPC1112FHxxx/202",	0x2524902b,	16	},
	{ NULL, }
}, *device = NULL;


static void identify(void)
{
	const char *res;
	unsigned id;

	res = dialog_rc(100, "J");
	if (sscanf(res, "%u", &id) != 1) {
		fprintf(stderr, "J: cannot parse ID \"%s\"\n", res);
		exit(1);
	}

	for (device = devices; device->name; device++)
		if (device->id == id) {
			if (!quiet)
				fprintf(stderr, "%s (0x%04x %04x) %d kB\n",
				    device->name, id >> 16, id & 0xffff,
				    device->flash_kb);
			return;
		}

	fprintf(stderr, "unknown device 0x%04x %04x\n", id >> 16, id & 0xffff);
	exit(1);
}


/* ----- ISP session ------------------------------------------------------- */


static void at_exit(void)
{
	ubb_close(0);
}


static void start_isp(void)
{
	const char *res;

	if (ubb_open(0) < 0) {
		perror("ubb_open");
		exit(1);
	}
	atexit(at_exit);

	ubb_power(1);

	usleep(100*1000);

	SET(TGT_nRESET);
	OUT(TGT_nRESET);

	CLR(TGT_nISP);
	OUT(TGT_nISP);

	swuart_open(HOST_TX, HOST_RX, 115200);

	if (!autobaud()) {
		fprintf(stderr, "target is not responding\n");
		exit(1);
	}

	res = dialog(100, "12000");
	if (strcmp(res, "OK")) {
		fprintf(stderr, "cannot set clock rate\n");
		exit(1);
	}
}


/* ----- Command-line processing ------------------------------------------- */


static void usage(const char *name)
{
	fprintf(stderr,
"usage: %s [-q] [-v ...]\n\n"
"  -q  suppress basic progress messages\n"
"  -v  increase verbosity level\n"
    , name);
	exit(1);
}


int main(int argc, char **argv)
{
	int c;

	while ((c = getopt(argc, argv, "qv")) != EOF)
		switch (c) {
		case 'q':
			quiet = 1;
			break;
		case 'v':
			verbose++;
			break;
		default:
			usage(*argv);
		}

	switch (argc-optind) {
	case 0:
		break;
	default:
		usage(*argv);
	}

	start_isp();

	identify();

	return 0;
}