nuttx/boards/risc-v/fe310/hifive1-revb/src/fe310_buttons.c

/****************************************************************************
 * boards/risc-v/fe310/hifive1-revb/src/fe310_buttons.c
 *
 *   Copyright (C) 2019 Masayuki Ishikawa. All rights reserved.
 *   Author: Masayuki Ishikawa <masayuki.ishikawa@gmail.com>
 *
 * 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 <nuttx/board.h>
#include <nuttx/arch.h>

#include <stdbool.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>

#include "fe310_gpio.h"
#include "fe310.h"
#include "hifive1-revb.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define GPIO_BTN (GPIO_MODE_INIRQ | GPIO_INT_BOTH | GPIO_PULLUP | GPIO_PIN23)
#define BTN_IRQ  FE310_IRQ_GPIO23

/****************************************************************************
 * 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.
 *
 ****************************************************************************/

void board_button_initialize(void)
{
  fe310_gpio_config(GPIO_BTN);
}

/****************************************************************************
 * 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.
 *
 ****************************************************************************/

uint32_t board_buttons(void)
{
  uint8_t ret = 0;
  int i = 0;
  int n = 0;

  bool b0 = fe310_gpio_read(GPIO_BTN);

  for (i = 0; i < 10; i++)
    {
      up_mdelay(1); /* TODO */

      bool b1 = fe310_gpio_read(GPIO_BTN);

      if (b0 == b1)
        {
          n++;
        }
      else
        {
          n = 0;
        }

      if (3 == n)
        {
          break;
        }

      b0 = b1;
    }

  iinfo("b=%d n=%d \n", b0, n);

  /* Low value means that the button is pressed */

  if (!b0)
    {
      ret = 0x1;
    }

  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;
  ASSERT(id == 0);

  if (NULL != irqhandler)
    {
      /* Attach the new button handler. */

      ret = irq_attach(BTN_IRQ, irqhandler, arg);

      /* Then make sure that interrupts are enabled on the pin */

      up_enable_irq(BTN_IRQ);
    }
  else
    {
      up_disable_irq(BTN_IRQ);
    }

  return ret;
}
#endif