text: /****************************************************************************
   * boards/arm/imxrt/imxrt1064-evk/src/imxrt_buttons.c
   *
   *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
   *   Authors: Gregory Nutt <gnutt@nuttx.org>
   *            David Sidrane <david_s5@nscdg.com>
   *            Dave Marples <dave@marples.net>
   *
   * 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. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "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
   * COPYRIGHT OWNER OR CONTRIBUTORS 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.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <sys/types.h>
  #include <errno.h>
  
  #include <nuttx/arch.h>
  #include <nuttx/irq.h>
  #include <arch/board/board.h>
  
  #include "arm_arch.h"
  
  #include "imxrt_config.h"
  #include "imxrt_irq.h"
  #include "imxrt_gpio.h"
  #include "imxrt1064-evk.h"
  
  #ifdef CONFIG_ARCH_BUTTONS
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /* The IMXRT has 1 user button (SW8)):
   *
   * 1. SW8 (IRQ88)   GPIO5-00
   */
  
  const uint32_t gpio_pins[NUM_BUTTONS]     =
                                              {
                                                GPIO_SW8
                                              };
  const uint32_t gpio_pins_int[NUM_BUTTONS] =
                                              {
                                                GPIO_SW8_INT
                                              };
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: board_button_initialize
   *
   * Description:
   *   board_button_initialize() must be called to initialize button resources.
   *   After that, board_buttons() may be called to collect the current state
   *   of all buttons or board_button_irq() may be called to register button
   *   interrupt handlers.
   *
   ****************************************************************************/
  
  uint32_t board_button_initialize(void)
  {
    uint32_t i;
  
    /* Configure the buttons as input */
  
    for (i = 0; i < NUM_BUTTONS; i++)
      {
        imxrt_config_gpio(gpio_pins[i]);
      }
  
    return NUM_BUTTONS;
  }
  
  /****************************************************************************
   * Name: board_buttons
   *
   * Description:
   *   After board_button_initialize() has been called, board_buttons() may be
   *   called to collect the state of all buttons.  board_buttons() returns an
   *   8-bit bit set with each bit associated with a button.  See the
   *   BUTTON_*_BIT  definitions in board.h for the meaning of each bit.
   *
   ****************************************************************************/
  
  uint8_t board_buttons(void)
  {
    uint8_t ret = 0;
    uint8_t i   = 0;
  
    for (i = 0; i < NUM_BUTTONS; i++)
      {
        ret |= ((!imxrt_gpio_read(gpio_pins[i])) << i);
      }
  
    return ret;
  }
  
  /****************************************************************************
   * Name: board_button_irq
   *
   * Description:
   *   board_button_irq() may be called to register an interrupt handler that
   *   will be called when a button is depressed or released.  The ID value is
   *   a button enumeration value that uniquely identifies a button resource.
   *   See the BUTTON_* definitions in board.h for the meaning of enumeration
   *   value.
   *
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
  int board_button_irq(int id, xcpt_t irqhandler, FAR void *arg)
  {
    int ret = -EINVAL;
  
    /* The button has already been configured as an interrupting input (by
     * board_button_initialize() above).
     *
     * Attach the new button handler.
     */
  
    if (id < NUM_BUTTONS)
      {
        uint32_t irqnum = gpio_pins_int[id];
        if (irqhandler)
          {
            ret = irq_attach(irqnum, irqhandler, arg);
            imxrt_gpioirq_enable (irqnum);
  
            /* Then make sure that interrupts are enabled on the pin */
  
            up_enable_irq(irqnum);
          }
        else
          {
            up_disable_irq(irqnum);
            imxrt_gpioirq_disable(irqnum);
            ret = OK;
          }
      }
  
    return ret;
  }
  #endif
  #endif /* CONFIG_ARCH_BUTTONS */
  