text: /****************************************************************************
   * arch/arm/src/stm32f7/stm32_exti_pwr.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  #include <nuttx/irq.h>
  #include <nuttx/arch.h>
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <errno.h>
  
  #include <arch/irq.h>
  
  #include "arm_internal.h"
  #include "chip.h"
  #include "stm32_gpio.h"
  #include "stm32_exti.h"
  #include "stm32_exti_pwr.h"
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  /* Interrupt handlers attached to the PVD EXTI */
  
  static xcpt_t g_pvd_callback;
  static void  *g_callback_arg;
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: stm32_exti_pvd_isr
   *
   * Description:
   *   EXTI PVD interrupt service routine/dispatcher
   *
   ****************************************************************************/
  
  static int stm32_exti_pvd_isr(int irq, void *context, void *arg)
  {
    int ret = OK;
  
    /* Clear the pending EXTI interrupt */
  
    putreg32(EXTI_PVD_LINE, STM32_EXTI_PR);
  
    /* And dispatch the interrupt to the handler */
  
    if (g_pvd_callback)
      {
        ret = g_pvd_callback(irq, context, g_callback_arg);
      }
  
    return ret;
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: stm32_exti_pvd
   *
   * Description:
   *   Sets/clears EXTI PVD interrupt.
   *
   * Input Parameters:
   *  - rising/falling edge: enables interrupt on rising/falling edge
   *  - event:  generate event when set
   *  - func:   when non-NULL, generate interrupt
   *
   * Returned Value:
   *   Zero (OK) returned on success; a negated errno value is returned on
   *   failure.
   *
   ****************************************************************************/
  
  int stm32_exti_pvd(bool risingedge, bool fallingedge, bool event,
                     xcpt_t func, void *arg)
  {
    /* Get the previous GPIO IRQ handler; Save the new IRQ handler. */
  
    g_pvd_callback = func;
    g_callback_arg = arg;
  
    /* Install external interrupt handlers (if not already attached) */
  
    if (func)
      {
        irq_attach(STM32_IRQ_PVD, stm32_exti_pvd_isr, NULL);
        up_enable_irq(STM32_IRQ_PVD);
      }
    else
      {
        up_disable_irq(STM32_IRQ_PVD);
      }
  
    /* Configure rising/falling edges */
  
    modifyreg32(STM32_EXTI_RTSR,
                risingedge ? 0 : EXTI_PVD_LINE,
                risingedge ? EXTI_PVD_LINE : 0);
    modifyreg32(STM32_EXTI_FTSR,
                fallingedge ? 0 : EXTI_PVD_LINE,
                fallingedge ? EXTI_PVD_LINE : 0);
  
    /* Enable Events and Interrupts */
  
    modifyreg32(STM32_EXTI_EMR,
                event ? 0 : EXTI_PVD_LINE,
                event ? EXTI_PVD_LINE : 0);
    modifyreg32(STM32_EXTI_IMR,
                func ? 0 : EXTI_PVD_LINE,
                func ? EXTI_PVD_LINE : 0);
  
    return OK;
  }
  