gpio-ext-pcal9535a.h

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#ifndef DRIVER_IO_EXPANDER_PCAL9535A_H
#define DRIVER_IO_EXPANDER_PCAL9535A_H
/**********************************************************************/
/*
 * Copyright (c) 2015, Jetro AS
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONRIBUTORS ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the EVE platform.
 */

/**
 * \file
 * @brief Driver for I2C-based IO expander type NXP PCAL9535A.
 *
 * @author KLO, Jetro AS
 */ /******************************************************************/

#include <stdbool.h>
#include <string.h>
#include "gpio-ext.h"

/**
 * \defgroup gpio_ext_pcal9535a PCAL9535a GPIO driver
 * \ingroup gpio_ext
 * \ingroup extdrv
 * \{
 *
 * This driver supports the I2C-based IO expander type NXP PCAL9535A.
 * The IO expander has 2 8-bits IO ports, 1 open drain interrupt output
 * and 3 address lines. Both IO ports are operated as one common 16-bits
 * port with PORT1 as MSByte and PORT0 as LSByte.
 * The I2C address range is 0x20 - 0x27. Max baudrate is 400 kbit/s.
 * The port bits could be set to inputs or outputs individually.
 * Each input can be configured to have pullup or pulldown resistors.
 *
 * The selected I2C port must be initialized before using the driver.
 */

/**
 * io_expander_state_t structure holds run-time data for the IO expander instance.
 *
 */
struct gpio_ext_pcal_state_t
{
  uint16_t OutputValues;      ///< Last values set for output to IO_EXPANDER_OUTPUT register
  uint16_t InputValues;       ///< Last read input values, copy of IO_EXPANDER_INPUT register
  uint16_t InterruptStatus;   ///< Pending interrupt status
  uint16_t InterruptMask;     ///< Internal interrupt bit mask (0 = disabled, 1 = enabled), inverted copy of IO_EXPANDER_INT_MASK register.
  uint16_t Direction;         ///< Current direction state, copy of IO_EXPANDER_DIRECTION register
};

/**
 * io_expander_t structure holds I2C port and slave address to be used,
 * and the initial data for the ports.
 *
 */

struct gpio_ext_pcal_t
{
  const struct i2c_t* I2c;    ///< I2C port I2C0 or I2C1
  struct gpio_ext_pcal_state_t* State; ///< IO expander run-time state
  uint8_t SlaveAddress;       ///< I2C slave address 0x20 to 0x27
  uint8_t Reserved;           ///< Reserved and not used
  uint16_t OutInit;           ///< Initialize value for output port pins          (0 = low output, 1 = high output)
  uint16_t InInvert;          ///< Invertion of inputs port pins                  (0 = no invert, 1 = invert)
  uint16_t Direction;         ///< Sets the direction of port pins                (0 = output, 1 = input)
  uint16_t PullEnable;        ///< Enables pull resistors for port pins           (0 = disable, 1 = enable)
  uint16_t PullSelect;        ///< Selects pullup or polldown resistors port pins (0 = 100k pulldown, 1 = 100k pullup)
};

/**********************************************************************
 * IO port expander commands
 **********************************************************************/
#define IO_EXPANDER_INPUT                         0x00
#define IO_EXPANDER_OUTPUT                        0x02
#define IO_EXPANDER_INVERT                        0x04
#define IO_EXPANDER_DIRECTION                     0x06
#define IO_EXPANDER_DRIVE_PORT0                   0x40
#define IO_EXPANDER_DRIVE_PORT1                   0x42
#define IO_EXPANDER_INPUT_LATCH_ENABLE            0x44
#define IO_EXPANDER_PULL_ENABLE                   0x46
#define IO_EXPANDER_PULL_SELECT                   0x48
#define IO_EXPANDER_INT_MASK                      0x4a
#define IO_EXPANDER_INT_STATUS                    0x4c
#define IO_EXPANDER_OUTPUT_CONFIG                 0x4f

/**
 * Pointer to GpioPcalFunc structure uses to initialize the array of GPIO
 * virtual functions .Func in struct ext_gpio_t GPIO descriptor.
 */
extern const struct gpio_ext_api_t GpioPcalFunc;

/**
  * @name Functions called from application programs
  * @{
  */

/**********************************************************************
 * prototypes used by inline functions
 **********************************************************************/
extern uint16_t ReadPcal(const struct gpio_ext_t* GpioExt, uint8_t Address);
extern void WritePcal(const struct gpio_ext_t* GpioExt, uint8_t Address, uint16_t Data);

/**
 * @brief Initialize I2C-based IO expander type NXP PCAL9535A.
 *
 * @param GpioExt  Parameters for the IO port expander to be used
 */
static inline void GpioExtInitPcal(const struct gpio_ext_t *GpioExt)
{
  // nothing to do
}

/**
 * @brief De-initialize I2C-based IO expander type NXP PCAL9535A.
 *
 * @param GpioExt  Parameters for the IO port expander to be used
 * @return         true if OK, else false
 */
static inline void GpioExtDisablePcal(const struct gpio_ext_t *GpioExt)
{
  // nothing to do
}

/**
 * @brief Name:       GpioExtInPortPcal\n
 * Read 16-bits data from GPIO port.
 *
 * @param GpioExt  Parameters for the IO port expander to be used
 * @return         Data read
 */
static inline uint16_t GpioExtInPortPcal(const struct gpio_ext_t *GpioExt)
{
  return ReadPcal(GpioExt, IO_EXPANDER_INPUT);
}

/**
 * @brief Name:       GpioExtOutPortPcal\n
 * Write 16-bits data to GPIO port.
 *
 * @param GpioExt  Parameters for the IO port expander to be used
 * @param Data     Data to be written to IO expander ports
 */
static inline void GpioExtOutPortPcal(const struct gpio_ext_t *GpioExt, uint16_t Data)
{
  WritePcal(GpioExt, IO_EXPANDER_OUTPUT, Data);
}

/**
 * @brief Set pins direction to GPIO port.
 *
 * @param GpioExt     Parameters for the IO port expander to be used
 * @param Direction   New direction to be settled
 */
static inline void GpioExtSetDirectionPcal(const struct gpio_ext_t* GpioExt,
                                           uint16_t Direction)
{
  // NB: register contains an inverted value
  WritePcal(GpioExt, IO_EXPANDER_DIRECTION, ~Direction);
}

/**
 * @brief Select pullup or pulldown for GPIO port.
 *
 * @param GpioExt     Parameters for the IO port expander to be used
 * @param PullSelect  0 - pulldown, 1 - pullup
 */
static inline void GpioExtSetPullSelectPcal(const struct gpio_ext_t* GpioExt,
                                            uint16_t PullSelect)
{
  WritePcal(GpioExt, IO_EXPANDER_PULL_SELECT, PullSelect);
}

/**
 * @brief Enable pullup/pulldown to GPIO port.
 *
 * @param GpioExt     Parameters for the IO port expander to be used
 * @param PullEnable  0 - disable, 1 - enable
 */
static inline void GpioExtSetPullEnablePcal(const struct gpio_ext_t* GpioExt,
                                            uint16_t PullEnable)
{
  WritePcal(GpioExt, IO_EXPANDER_PULL_ENABLE, PullEnable);
}

static inline void GpioExtSetInterruptsPcal(const struct gpio_ext_t *GpioExt,
                                            uint16_t Mask)
{
  GpioExt->State->InterruptMask = Mask;
  // NB: register contains an inverted value
  WritePcal(GpioExt, IO_EXPANDER_INT_MASK, ~Mask);
}

static inline void GpioExtSetLatchPcal(const struct gpio_ext_t *GpioExt,
                                       uint16_t Mask)
{
  WritePcal(GpioExt, IO_EXPANDER_INPUT_LATCH_ENABLE, Mask);
}

extern void GpioExtSetDrivePcal(const struct gpio_ext_t *GpioExt, uint8_t Values[]);

/** \} */

/** \} gpio_ext_pcal9535a */

#endif //DRIVER_IO_EXPANDER_PCAL9535A_H