io-expander-pcal9535a.h

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#ifndef DRIVER_IO_EXPANDER_PCAL9535A_H
#define DRIVER_IO_EXPANDER_PCAL9535A_H
/**********************************************************************/
/*
 * Copyright (c) 2014, 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>

/**
 * 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.
 */

/***********************************************************************
 * Global defines
***********************************************************************/
/**
 * io_expander_state_t structure holds run-time data for the IO expander instance.
 *
 */
struct io_expander_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 io_expander_t
{
  const struct i2c_t *I2c;    ///< I2C port I2C0 or I2C1
  struct io_expander_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

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

/**********************************************************************
 * prototypes used by inline functions
 **********************************************************************/
extern bool IoExpanderRead(const struct io_expander_t *IoExpander, const uint8_t Address, uint16_t *Data);
extern bool IoExpanderWrite(const struct io_expander_t *IoExpander, const uint8_t Address, const uint16_t Data);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortInit\n
 * Initializes I2C-based IO expander type NXP PCAL9535A.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @return            true if OK, else false
 ***********************************************************************/
extern bool IoExpPortInit(const struct io_expander_t *IoExpander);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortRead\n
 * Read 16-bits data from IO expander ports.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param In          Pointer to put data read from IO expander ports
 * @return            true if OK, else false
 ***********************************************************************/
extern bool IoExpPortRead(const struct io_expander_t *IoExpander, uint16_t *In);

/**********************************************************************/
/*
 * @brief Name:       IoExpPortWrite\n
 * Write 16-bits data to IO expander ports.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Out         Data to be written to IO expander ports
 * @return            true if OK, else false
 ***********************************************************************/
extern bool IoExpPortWrite(const struct io_expander_t *IoExpander, const uint16_t Out, const uint16_t Mask);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortInterruptsRead\n
 * Read and clear interrupt status from the IO expander.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @return            bit mask with bits set for every unmasked pending interrupt
 ***********************************************************************/
extern uint16_t IoExpPortInterruptsRead(const struct io_expander_t *IoExpander);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortInterruptsEnable\n
 * Enable (unmask) interrupts for the selected set of pins.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Mask        Pin bitmap
 * @return            true if OK, else false
 ***********************************************************************/
extern bool IoExpPortInterruptsEnable(const struct io_expander_t *IoExpander, uint16_t Mask);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortInterruptsDisable\n
 * Disable (mask) interrupts for the selected set of pins.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Mask        Pin bitmap
 * @return            true if OK, else false
 ***********************************************************************/
extern bool IoExpPortInterruptsDisable(const struct io_expander_t *IoExpander, uint16_t Mask);

/**********************************************************************/
/**
 * @brief Name:       IoExpPortInterruptsDisable\n
 * Clear (remove pending status) interrupts for the selected set of pins.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Mask        Pin bitmap
 * @return            true if OK, else false
 ***********************************************************************/
extern void IoExpPortInterruptsClear(const struct io_expander_t *IoExpander, uint16_t Mask);


/**********************************************************************/
/**
 * @brief Name:       IoExpPortSet\n
 * Sets IO expander port bits.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param SetBits     Bits to be set at IO expander ports
 * @return            true if OK, else false
 ***********************************************************************/
static inline bool IoExpPortSet(const struct io_expander_t *IoExpander, const uint16_t SetBits)
{
  return IoExpPortWrite(IoExpander, SetBits, SetBits);
}

/**********************************************************************/
/**
 * @brief Name:       IoExpPortClear\n
 * Clears IO expander port bits.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param ClearBits   Bits to be cleared at IO expander ports
 * @return            true if OK, else false
 ***********************************************************************/
static inline bool IoExpPortClear(const struct io_expander_t *IoExpander, const uint16_t ClearBits)
{
  return IoExpPortWrite(IoExpander, ~ClearBits, ClearBits);
}

/**********************************************************************/
/**
 * @brief Name:       IoExpPortDirection\n
 * Set IO expander ports to input and output.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Direction   0 = output, 1 = input
 * @return            true if OK, else false
 ***********************************************************************/
static inline bool IoExpPortDirection(const struct io_expander_t *IoExpander, const uint16_t Direction)
{
  IoExpander->State->Direction = Direction;
  return IoExpanderWrite(IoExpander, IO_EXPANDER_DIRECTION, Direction);
}

/**********************************************************************/
/**
 * @brief Name:       IoExpPortDriveSet\n
 * Set output drive strength for IO expander ports.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param Drive       Output drive strength data for the port bits
 *                    00 = 25%, 01 = 50%, 10 = 75%, 11 = 100% for each bit
 * @return            true if OK, else false
 ***********************************************************************/
static inline bool IoExpPortDriveSet(const struct io_expander_t *IoExpander, const uint32_t Drive)
{
  if (IoExpanderWrite(IoExpander, IO_EXPANDER_DRIVE_PORT0, (uint16_t)Drive) &&
      IoExpanderWrite(IoExpander, IO_EXPANDER_DRIVE_PORT1, (uint16_t)(Drive >> 16)))
    return true;
  else
    return false;
}

/**********************************************************************/
/**
 * @brief Name:       IoExpPortPullResistorSet\n
 * Disables/enables pullup/pulldown resistors for IO expander port pins.
 *
 * @param IoExpander  Parameters for the IO port expander to be used
 * @param PullEnable  Enable pull resistors for port pins
 *                    0 = disable, 1 = enable
 * @param PullSelect  Sets pullup or polldown resistors for port pins
 *                    0 = 100k pulldown, 1 = 100k pullup
 * @return            true if OK, else false
 ***********************************************************************/
static inline bool IoExpPortPullResistorSet(const struct io_expander_t *IoExpander, const uint16_t PullEnable, const uint16_t PullSelect)
{
  if (IoExpanderWrite(IoExpander, IO_EXPANDER_PULL_SELECT, PullSelect) &&
      IoExpanderWrite(IoExpander, IO_EXPANDER_PULL_ENABLE, PullEnable))
    return true;
  else
    return false;
}

/** @} */
#endif //DRIVER_IO_EXPANDER_PCAL9535A_H