text: /************************************************************************************
   * configs/sama5d3-xplained/src/sam_pwm.c
   *
   *   Copyright (C) 2014-2015 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 <sys/types.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/board.h>
  #include <nuttx/pwm.h>
  
  #include <arch/board/board.h>
  
  #include "sam_pwm.h"
  #include "sama5d3-xplained.h"
  
  /************************************************************************************
   * Pre-processor Definitions
   ************************************************************************************/
  /* Configuration ********************************************************************/
  /* PWM.  There are no dedicated PWM output pins available to the user for PWM
   * testing.  Care must be taken because all PWM output pins conflict with some other
   * usage of the pin by other devices:
   *
   *    -----+---+---+----+--------------------
   *     PWM  PIN PER PIO  CONFLICTS
   *    -----+---+---+----+--------------------
   *     PWM0 FI   B  PC28   SPI1, ISI
   *          H    B  PB0    GMAC
   *               B  PA20   LCDC, ISI
   *          L    B  PB1    GMAC
   *               B  PA21   LCDC, ISI
   *    -----+---+---+----+--------------------
   *     PWM1 FI   B  PC31   HDMI
   *          H    B  PB4    GMAC
   *               B  PA22   LCDC, ISI
   *          L    B  PB5    GMAC
   *               B  PE31   ISI, HDMI
   *               B  PA23   LCDC, ISI
   *    -----+---+---+----+--------------------
   *     PWM2 FI   B  PC29   UART0, ISI, HDMI
   *          H    C  PD5    HSMCI0
   *               B  PB8    GMAC
   *          L    C  PD6    HSMCI0
   *               B  PB9    GMAC
   *    -----+---+---+----+--------------------
   *     PWM3 FI   C  PD16   SPI0, Audio
   *          H    C  PD7    HSMCI0
   *               B  PB12   GMAC
   *          L    C  PD8    HSMCI0
   *               B  PB13   GMAC
   *    -----+---+---+----+--------------------
   */
  
  #ifndef CONFIG_SAMA5D3XPLAINED_CHANNEL
  #  if defined(CONFIG_SAMA5_PWM_CHAN0)
  #    warning Assuming PWM channel 0
  #    define CONFIG_SAMA5D3XPLAINED_CHANNEL 0
  #  elif defined(CONFIG_SAMA5_PWM_CHAN1)
  #    warning Assuming PWM channel 1
  #    define CONFIG_SAMA5D3XPLAINED_CHANNEL 1
  #  elif defined(CONFIG_SAMA5_PWM_CHAN2)
  #    warning Assuming PWM channel 2
  #    define CONFIG_SAMA5D3XPLAINED_CHANNEL 2
  #  elif defined(CONFIG_SAMA5_PWM_CHAN3)
  #    warning Assuming PWM channel 3
  #    define CONFIG_SAMA5D3XPLAINED_CHANNEL 3
  #  endif
  #endif
  
  #if defined(CONFIG_PWM) && defined(CONFIG_SAMA5_PWM)
  
  /************************************************************************************
   * Private Functions
   ************************************************************************************/
  
  /************************************************************************************
   * Public Functions
   ************************************************************************************/
  
  /************************************************************************************
   * Name: board_pwm_setup
   *
   * Description:
   *   All SAMA5 architectures must provide the following interface to work with
   *   examples/pwm.
   *
   ************************************************************************************/
  
  int board_pwm_setup(void)
  {
    static bool initialized = false;
    struct pwm_lowerhalf_s *pwm;
    int ret;
  
    /* Have we already initialized? */
  
    if (!initialized)
      {
        /* Call sam_pwminitialize() to get an instance of the PWM interface */
  
        pwm = sam_pwminitialize(CONFIG_SAMA5D3XPLAINED_CHANNEL);
        if (!pwm)
          {
            err("ERROR: Failed to get the SAMA5 PWM lower half\n");
            return -ENODEV;
          }
  
        /* Register the PWM driver at "/dev/pwm0" */
  
        ret = pwm_register("/dev/pwm0", pwm);
        if (ret < 0)
          {
            aerr("ERROR: pwm_register failed: %d\n", ret);
            return ret;
          }
  
        /* Now we are initialized */
  
        initialized = true;
      }
  
    return OK;
  }
  
  #endif /* CONFIG_PWM */
  