text: /****************************************************************************
   * boards/arm/samd2l2/samd21-xplained/src/sam_autoleds.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.
   *
   ****************************************************************************/
  
  /* There are three LEDs on board the SAMD21 Xplained Pro board:  The EDBG
   * controls two of the LEDs, a power LED and a status LED.  There is only
   * one user controllable LED, a yellow LED labelled STATUS near the SAMD21
   * USB connector.
   *
   * This LED is controlled by PB30 and the LED can be activated by driving
   * PB30 to GND.
   *
   * When CONFIG_ARCH_LEDS is defined in the NuttX configuration, NuttX will
   * control the LED as follows:
   *
   *   SYMBOL              Meaning                 LED
   *   ------------------- ----------------------- ------
   *   LED_STARTED         NuttX has been started  OFF
   *   LED_HEAPALLOCATE    Heap has been allocated OFF
   *   LED_IRQSENABLED     Interrupts enabled      OFF
   *   LED_STACKCREATED    Idle stack created      ON
   *   LED_INIRQ           In an interrupt**       N/C
   *   LED_SIGNAL          In a signal handler***  N/C
   *   LED_ASSERTION       An assertion failed     N/C
   *   LED_PANIC           The system has crashed  FLASH
   *
   * Thus if the LED is statically on, NuttX has successfully  booted and is,
   * apparently, running normally.  If the LED is flashing at approximately
   * 2Hz, then a fatal error has been detected and the system has halted.
   */
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <assert.h>
  #include <debug.h>
  
  #include <nuttx/board.h>
  #include <arch/board/board.h>
  
  #include "sam_port.h"
  #include "samd21-xplained.h"
  
  #ifdef CONFIG_ARCH_LEDS
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: board_autoled_initialize
   ****************************************************************************/
  
  void board_autoled_initialize(void)
  {
    sam_configport(PORT_STATUS_LED);
  }
  
  /****************************************************************************
   * Name: board_autoled_on
   ****************************************************************************/
  
  void board_autoled_on(int led)
  {
    bool ledstate = true;
  
    switch (led)
      {
      case 0:   /* LED_STARTED:      NuttX has been started  STATUS LED=OFF
                 * LED_HEAPALLOCATE: Heap has been allocated STATUS LED=OFF
                 * LED_IRQSENABLED:  Interrupts enabled      STATUS LED=OFF
                 */
  
        break;   /* Leave ledstate == true to turn OFF */
  
      default:
      case 2:   /* LED_INIRQ:        In an interrupt         STATUS LED=N/C
                 * LED_SIGNAL:       In a signal handler     STATUS LED=N/C
                 * LED_ASSERTION:    An assertion failed     STATUS LED=N/C
                 */
  
        return; /* Return to leave STATUS LED unchanged */
  
      case 3:   /* LED_PANIC:        The system has crashed  STATUS LED=FLASH */
      case 1:   /* LED_STACKCREATED: Idle stack created      STATUS LED=ON */
  
        ledstate = false;       /* Set ledstate == false to turn ON */
        break;
      }
  
    sam_portwrite(PORT_STATUS_LED, ledstate);
  }
  
  /****************************************************************************
   * Name: board_autoled_off
   ****************************************************************************/
  
  void board_autoled_off(int led)
  {
    switch (led)
      {
      /* These should not happen and are ignored */
  
      default:
      case 0:   /* LED_STARTED:      NuttX has been started  STATUS LED=OFF
                 * LED_HEAPALLOCATE: Heap has been allocated STATUS LED=OFF
                 * LED_IRQSENABLED:  Interrupts enabled      STATUS LED=OFF
                 */
  
      case 1:   /* LED_STACKCREATED: Idle stack created      STATUS LED=ON */
  
      /* These result in no-change */
  
      case 2:   /* LED_INIRQ:        In an interrupt         STATUS LED=N/C
                 * LED_SIGNAL:       In a signal handler     STATUS LED=N/C
                 * LED_ASSERTION:    An assertion failed     STATUS LED=N/C
                 */
  
        return; /* Return to leave STATUS LED unchanged */
  
      /* Turn STATUS LED off set driving the output high */
  
      case 3:   /* LED_PANIC:        The system has crashed  STATUS LED=FLASH */
        sam_portwrite(PORT_STATUS_LED, true);
        break;
      }
  }
  
  #endif /* CONFIG_ARCH_LEDS */
  