text: /*
   * Copyright (c) 2008, Google Inc.
   * Copyright (c) 2012, Travis Geiselbrecht
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *  * Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *  * 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.
   *
   * 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.
   */
  
  #ifndef __DEV_GPIO_H
  #define __DEV_GPIO_H
  
  enum gpio_flags {
      GPIO_INPUT      = (1 << 0),
      GPIO_OUTPUT     = (1 << 1),
      GPIO_LEVEL      = (1 << 2),
      GPIO_EDGE       = (1 << 3),
      GPIO_RISING     = (1 << 4),
      GPIO_FALLING    = (1 << 5),
      GPIO_HIGH       = (1 << 6),
      GPIO_LOW        = (1 << 7),
      GPIO_PULLUP     = (1 << 8),
      GPIO_PULLDOWN   = (1 << 9),
  };
  
  /* top 16 bits of the gpio flags are platform specific */
  #define GPIO_PLATFORM_MASK 0xffff0000
  
  int gpio_config(unsigned nr, unsigned flags);
  void gpio_set(unsigned nr, unsigned on);
  int gpio_get(unsigned nr);
  
  #endif
  