/***************************************************************************
 *   Copyright (C) 09/2007 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.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; version 2 of the License,               *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>

#include <linux/i2c.h>
#include <linux/i2c-dev.h>

#include "gtk2-gui.h"
#include "i2c.h"

/* TWIBOOT commands */
#define CMD_GET_INFO		0x10
#define CMD_GET_SIGNATURE	0x11
#define CMD_WRITE_FLASH		0x12
#define CMD_READ_FLASH		0x13
#define CMD_WRITE_EEPROM	0x14
#define CMD_READ_EEPROM		0x15
#define CMD_BOOT_APPLICATION	0x1F

#define COOKIE			0x4711
#define WRITE_COOKIE		COOKIE

#define FLASH_BLKSIZE		0x40

/* blctrl commands */
//#define CMD_GET_INFO		0x10
#define CMD_SET_PWM		0x21
#define CMD_GET_STATUS		0x22
#define CMD_SET_PARAM		0x23
#define CMD_GET_PARAM		0x24
#define CMD_BOOT_LOADER		0x2F

static int i2c_connected;

void i2c_enumerate_interfaces(void)
{
	gui_flush_i2c_interfaces();

	char path[64];
	strcpy(path, "/dev");

	DIR *dp = opendir(path);
	if (dp == NULL) {
		perror("opendir()");
		return;
	}

	char *ptr = path + strlen(path);
	*ptr = '/';

	struct dirent *dentry;
	while ((dentry = readdir(dp)) != NULL) {
		if (!strcmp(dentry->d_name, "."))
			continue;

		if (!strcmp(dentry->d_name, ".."))
			continue;

		if (strncmp(dentry->d_name, "i2c-", 4) != 0)
			continue;

		strcpy(ptr +1, dentry->d_name);

		struct stat statbuf;
		if (stat(path, &statbuf) == -1) {
			perror("stat()");
			continue;
		}

		if (!S_ISCHR(statbuf.st_mode))
			continue;

		/* TODO: check permissions */

		gui_add_i2c_interface(path);
	}
	closedir(dp);
}

void i2c_close(int fd)
{
	i2c_connected = 0;
	i2c_close(fd);
}

int i2c_open(const char *path)
{
	int fd = open(path, O_RDWR);
	if (fd < 0) {
		perror("open()");
		return -1;
	}

	unsigned long funcs;
	if (ioctl(fd, I2C_FUNCS, &funcs)) {
		perror("ioctl(I2C_FUNCS)");
		i2c_close(fd);
		return -1;
	}

	if (!(funcs & I2C_FUNC_I2C)) {
		fprintf(stderr, "I2C_FUNC_I2C not supported!\n");
		i2c_close(fd);
		return -1;
	}

	i2c_connected = 1;
	return fd;
}

void i2c_set_address(int fd, int address)
{
	if (ioctl(fd, I2C_SLAVE, address) < 0) {
		perror("ioctl(I2C_SLAVE)");
		i2c_close(fd);
	}
}

int i2c_isconnected(void)
{
	return i2c_connected;
}


void i2c_cmd_bootloader(int fd)
{
	char cmd[] = { CMD_BOOT_LOADER };
	write(fd, cmd, 1);
}

void i2c_cmd_application(int fd)
{
	char cmd[] = { CMD_BOOT_APPLICATION };
	write(fd, cmd, 1);
}

void i2c_cmd_getinfo(int fd, char *buf, int size)
{
	char cmd[] = { CMD_GET_INFO };
	write(fd, cmd, 1);

	size = MIN(16, size);
	memset(buf, 0, size);
	read(fd, buf, size);

	int i;
	for (i = 0; i < size; i++)
		buf[i] &= ~0x80;
}

void i2c_cmd_getsignature(int fd, unsigned char *buf, int size)
{
	char cmd[] = { CMD_GET_SIGNATURE };
	write(fd, cmd, 1);

	memset(buf, 0, size);
	read(fd, buf, MIN(4, size));
}

void i2c_cmd_getparameters(int fd, struct blmc_parameter *blmc)
{
	char cmd[] = { CMD_GET_PARAM };
	write(fd, cmd, 1);

	memset(blmc, 0, sizeof(struct blmc_parameter));
	read(fd, blmc, sizeof(struct blmc_parameter));
}

void i2c_cmd_setparameters(int fd, struct blmc_parameter *blmc, int persistent)
{
	char cmd[sizeof(struct blmc_parameter) +1];
	cmd[0] = CMD_SET_PARAM;
	memcpy(cmd +1, blmc, sizeof(struct blmc_parameter));

	write(fd, cmd, sizeof(struct blmc_parameter) + (persistent ? 1 : -1));
}

int i2c_write_flash(int fd, char *data, int size, void (*progress_cb)(int pos, int size))
{
	int pos = 0;
	while (pos < size) {
		progress_cb(pos, size);

		char buf[FLASH_BLKSIZE +5];
		buf[0] = CMD_WRITE_FLASH;
		buf[1] = (pos >> 8) & 0xFF;
		buf[2] = pos & 0xFF;
		buf[3] = (COOKIE >> 8) & 0xFF;
		buf[4] = COOKIE & 0xFF;

		/* copy data and pad with 0xFF */
		int len = MIN(FLASH_BLKSIZE, size - pos);
		memcpy(buf +5, &data[pos], len);
		memset(buf +5 +len, 0xFF, FLASH_BLKSIZE - len);

		write(fd, buf, sizeof(buf));
		pos += len;
	}

	progress_cb(pos, size);
	return pos;
}

int i2c_read_flash(int fd, char *data, int size, void (*progress_cb)(int pos, int size))
{
	int pos = 0;
	while (pos < size) {
		progress_cb(pos, size);

		char cmd[3];
		cmd[0] = CMD_READ_FLASH;
		cmd[1] = (pos >> 8) & 0xFF;
		cmd[2] = pos & 0xFF;
		write(fd, cmd, 3);

		int len = MIN(FLASH_BLKSIZE, size - pos);
		read(fd, data + pos, len);

		pos += len;
	}

	progress_cb(pos, size);
	return pos;
}

int i2c_verify_flash(int fd, char *data, int size, void (*progress_cb)(int pos, int size))
{
	int pos = 0;
	while (pos < size) {
		progress_cb(pos, size);

		char cmd[3];
		cmd[0] = CMD_READ_FLASH;
		cmd[1] = (pos >> 8) & 0xFF;
		cmd[2] = pos & 0xFF;
		write(fd, cmd, 3);

		char buf2[FLASH_BLKSIZE];
		int len = MIN(FLASH_BLKSIZE, size - pos);
		read(fd, buf2, len);

		if (memcmp(data + pos, buf2, len) != 0)
			break;

		pos += len;
	}

	progress_cb(pos, size);
	return pos;
}

void i2c_cmd_setpwm(int fd, int pwm)
{
	char cmd[] = { CMD_SET_PWM, pwm };
	write(fd, cmd, 2);
}

void i2c_cmd_getstatus(int fd, struct blmc_status *status)
{
	char cmd[] = { CMD_GET_STATUS };
	write(fd, cmd, 1);

	memset(status, 0, sizeof(struct blmc_status));
	read(fd, status, sizeof(struct blmc_status));
}