/*
    test.c
    Copyright (C) 2011  Pali Rohár <pali.rohar@gmail.com>

    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 3 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, see <http://www.gnu.org/licenses/>.

*/

#include <sys/ioctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>


#define __u8 unsigned char
#define __u16 unsigned short int

/* 
 * Data for SMBus Messages 
 */
#define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */	
#define I2C_SMBUS_I2C_BLOCK_MAX	32	/* Not specified but we use same structure */
union i2c_smbus_data {
	__u8 byte;
	__u16 word;
	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
	                                            /* and one more for PEC */
};

/* This is the structure as used in the I2C_SMBUS ioctl call */
struct i2c_smbus_ioctl_data {
	char read_write;
	__u8 command;
	int size;
	union i2c_smbus_data *data;
};


int main() {

	int fd, ret;
	struct i2c_smbus_ioctl_data ioctl_data;
	union i2c_smbus_data data;

	printf("\ncall open(\"/dev/i2c-2\", %d);\n", O_RDWR);
	fd = open("/dev/i2c-2", O_RDWR);
	printf("fd=%d\n", fd);

	printf("\ncall ioctl(%d, 0x705, 0x55);\n", fd);
	ret = ioctl(fd, 0x705, 0x55);
	printf("ret=%d\n", ret);

	printf("\ncall ioctl(%d, 0x703, 0x55);\n", fd);
	ret = ioctl(fd, 0x703, 0x55);
	printf("ret=%d\n", ret);

	ioctl_data.read_write = 1;
	ioctl_data.command = 0x0B; /* Capacity in % */
	ioctl_data.size =  2 /* I2C_SMBUS_BYTE_DATA */;
	ioctl_data.data = &data;

	printf("\ncall ioctl(%d, 0x720, %p);\n", fd, &ioctl_data);
	ret = ioctl(fd, 0x720, &ioctl_data);
	printf("ret=%d\n", ret);

	printf("\ncall close(%d);\n", fd);
	ret = close(fd);
	printf("ret=%d\n", ret);
	printf("value=%d\n", ioctl_data.data->byte);

	return 0;

}