/*
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
/**
 * \file Driver for PCF8574 compartible remote 8-bit I/O expanders for I2C-bus
 * \author Ruslan V. Uss
 */
#ifndef PCF8574_PCF8574_H_
#define PCF8574_PCF8574_H_

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

#ifdef __cplusplus
extern "C"
{
#endif

/**
 * \brief Read GPIO port value
 * \param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * \return 8-bit GPIO port value
 */
uint8_t pcf8574_port_read(uint8_t addr);

/**
 * \brief Continiously read GPIO port values to buffer
 * @param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * @param buf Target buffer
 * @param len Buffer length
 * @return Number of bytes read
 */
size_t pcf8574_port_read_buf(uint8_t addr, void *buf, size_t len);

/**
 * \brief Write value to GPIO port
 * \param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * \param value GPIO port value
 */
void pcf8574_port_write(uint8_t addr, uint8_t value);

/**
 * \brief Continiously write GPIO values to GPIO port
 * \param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * @param buf Buffer with values
 * @param len Buffer length
 * @return Number of bytes written
 */
size_t pcf8574_port_write_buf(uint8_t addr, void *buf, size_t len);

/**
 * \brief Read input value of a GPIO pin
 * \param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * \param num pin number (0..7)
 * \return GPIO pin value
 */
bool pcf8574_gpio_read(uint8_t addr, uint8_t num);

/**
 * \brief Set GPIO pin output
 * Note it's READ - MODIFY - WRITE operation! Please read PCF8574
 * datasheet first.
 * \param addr I2C register address (0b0100<A2><A1><A0> for PCF8574)
 * \param num pin number (0..7)
 * \param value true for high level
 */
void pcf8574_gpio_write(uint8_t addr, uint8_t num, bool value);

#ifdef __cplusplus
}
#endif

#endif /* PCF8574_PCF8574_H_ */