text: /****************************************************************************
   * boards/arm/samv7/samv71-xult/src/sam_buttons.c
   *
   *   Copyright (C) 2014-2015, 2017 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * 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 <stdint.h>
  #include <errno.h>
  
  #include <nuttx/arch.h>
  #include <nuttx/board.h>
  #include <nuttx/irq.h>
  
  #include <nuttx/irq.h>
  #include <arch/board/board.h>
  
  #include "up_arch.h"
  #include "sam_gpio.h"
  #include "hardware/sam_matrix.h"
  #include "samv71-xult.h"
  
  #ifdef CONFIG_ARCH_BUTTONS
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
  #  define HAVE_IRQBUTTONS 1
  #  if !defined(CONFIG_SAMV7_GPIOA_IRQ) && !defined(CONFIG_SAMV7_GPIOB_IRQ)
  #    undef HAVE_IRQBUTTONS
  #  endif
  #endif
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: board_button_irqx
   *
   * Description:
   *   This function implements the core of the board_button_irq() logic.
   *
   ****************************************************************************/
  
  #ifdef HAVE_IRQBUTTONS
  static int board_button_irqx(gpio_pinset_t pinset, int irq, xcpt_t irqhandler,
                               void *arg)
  {
    irqstate_t flags;
  
    /* Disable interrupts until we are done.  This guarantees that the following
     * operations are atomic.
     */
  
    flags = enter_critical_section();
  
    /* Are we attaching or detaching? */
  
    if (irqhandler != NULL)
      {
        /* Configure the interrupt */
  
        sam_gpioirq(pinset);
        irq_attach(irq, irqhandler, arg);
        sam_gpioirqenable(irq);
      }
    else
      {
        /* Detach and disable the interrupt */
  
        irq_detach(irq);
        sam_gpioirqdisable(irq);
      }
  
    leave_critical_section(flags);
    return OK;
  }
  #endif
  
  /****************************************************************************
   * 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)
  {
    uint32_t regval;
  
    /* PB12 is set up as a system flash ERASE pin when the firmware boots. To
     * use the SW1, PB12 has to be configured as a normal regular I/O pin in
     * the MATRIX module. For more information see the SAM V71 datasheet.
     */
  
    regval  = getreg32(SAM_MATRIX_CCFG_SYSIO);
    regval |= MATRIX_CCFG_SYSIO_SYSIO12;
    putreg32(regval, SAM_MATRIX_CCFG_SYSIO);
  
    /* Configure button GPIOs */
  
    sam_configgpio(GPIO_SW0);
    sam_configgpio(GPIO_SW1);
  }
  
  /****************************************************************************
   * 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
   *   32-bit bit set with each bit associated with a button.  See the BUTTON*
   *   definitions above for the meaning of each bit in the returned value.
   *
   ****************************************************************************/
  
  uint32_t board_buttons(void)
  {
    uint32_t retval;
  
    retval  = sam_gpioread(GPIO_SW0) ? 0 : BUTTON_SW0_BIT;
    retval |= sam_gpioread(GPIO_SW1) ? 0 : BUTTON_SW1_BIT;
  
    return retval;
  }
  
  /****************************************************************************
   * Name: board_button_irq
   *
   * Description:
   *   This function may be called to register an interrupt handler that will
   *   be called when a button is depressed or released.  The ID value is one
   *   of the BUTTON* definitions provided above.
   *
   * Configuration Notes:
   *   Configuration CONFIG_AVR32_GPIOIRQ must be selected to enable the
   *   overall GPIO IRQ feature and CONFIG_AVR32_GPIOIRQSETA and/or
   *   CONFIG_AVR32_GPIOIRQSETB must be enabled to select GPIOs to support
   *   interrupts on.  For button support, bits 2 and 3 must be set in
   *   CONFIG_AVR32_GPIOIRQSETB (PB2 and PB3).
   *
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
  int board_button_irq(int id, xcpt_t irqhandler, FAR void *arg)
  {
  #ifdef HAVE_IRQBUTTONS
  
    switch (id)
      {
  #ifdef CONFIG_SAMV7_GPIOA_IRQ
        case BUTTON_SW0:
          return board_button_irqx(GPIO_SW0, IRQ_SW0, irqhandler, arg);
  #endif
  
  #ifdef CONFIG_SAMV7_GPIOB_IRQ
        case BUTTON_SW1:
          return board_button_irqx(GPIO_SW1, IRQ_SW1, irqhandler, arg);
  #endif
  
        default:
          return -EINVAL;
      }
  
  #else
  
    return -ENOSYS;
  
  #endif
  }
  #endif
  
  #endif /* CONFIG_ARCH_BUTTONS */
  