AD7291_COMMAND
ad7291_i2c_write(chip, AD7291_COMMAND, command);
ad7291_i2c_write(chip, AD7291_COMMAND, command);
ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval);
ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval);
ret = ad7291_i2c_write(chip, AD7291_COMMAND, AD7291_RESET);
ret = ad7291_i2c_write(chip, AD7291_COMMAND, chip->command);