static int ad5263_and_555_backlight_set(struct backlight_device *bl, int brightness)
{
struct ad5263_and_555_backlight_data *data = bl_get_data(bl);
struct ad5263_and_555_chip *chip = data->chip;
unsigned char value;
int ret;

if (brightness > MAX_BRIGHTNESS)
value = MAX_BRIGHTNESS;
else
value = brightness;

ret = ad5263_and_555_reg_write(chip->i2c, MAX8925_WLED_CNTL, value);
if (ret < 0)
goto out;

if (!data->current_brightness && brightness)
/* enable LED_ON output */


// ЧТО ПИСАТЬ ЗДЕСЬ? Здесь нужно 1 пин PCF8574а перевести в состояние "1"


dev_dbg(chip->dev, "Must be enabled baclight LED \n");
else if (!brightness)
/* disable LED_ON output */


// И ЗДЕСЬ? А здесь нужно 1 пин PCF8574а перевести в состояние "0"


dev_dbg(chip->dev, "Must be disabled baclight LED \n");
if (ret < 0)
goto out;
dev_dbg(chip->dev, "set brightness %d\n", value);
data->current_brightness = value;
return 0;
out:
dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
value, ret);
return ret;
}

#include "main.h"

using namespace std;

int open_wrap(int* file)
{
int adapter_nr = 0; /* probably dynamically determined */
char filename[20];

snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);

*file = open(filename, O_RDWR);
if (*file < 0) {
cerr << "Open err: "<< filename << endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}

int close_wrap(int file)
{
if (close(file) != 0){
cerr<<"Close err"<<endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}

int read_data(int file, unsigned char* buf)
{
if (!read(file, buf, 1)){
cerr<<"Read err"<<endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}

int write_data(int file, unsigned char* buf)
{
if (!write(file, buf, 1)){
cerr<<"Write err"<<endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}

int main(int argc, char** argv) {
cout.flags(ios::hex | ios::showbase | ios::left);

int addr;/* The I2C address */
int cycle_border;
int file;
int sleep_time;

cout<< "I2C address:";
cin >> addr;

cout<<"Cycle border:";
cin >> cycle_border;

cout<<"Sleep:";
cin>>sleep_time;


cout<<endl;
if (open_wrap(&file) != EXIT_SUCCESS) exit(EXIT_FAILURE);

if (ioctl(file, I2C_SLAVE, addr) < 0) {
/* ERROR HANDLING; you can check errno to see what went wrong */
cerr << "IOControl err:" << addr << endl;
goto close_exit;
}

unsigned char buf;
for(int i = 0; i < cycle_border; i++){
buf = 0;

if (read_data(file, &buf) !=0)
break;
cout<<addr<<"\t>\t"<<(int)buf<<endl;

buf = buf ^ 1;
if (write_data(file, &buf) !=0)
break;
cout<<addr<<"\t<\t"<<(int)buf<<endl;
usleep(sleep_time);
}

close_exit:
if (close_wrap(file) != EXIT_SUCCESS) exit(EXIT_FAILURE);

exit(EXIT_SUCCESS);
}