nuttx/configs/omnibusf4/src/stm32_pwm.c

/****************************************************************************
 * configs/omnibusf4/src/stm32_pwm.c
 *
 *   Copyright (C) 2019 Bill Gatliff. All rights reserved.
 *   Copyright (C) 2011, 2016 Gregory Nutt. All rights reserved.
 *   Author: Bill Gatliff <bgat@billgatliff.com>
 *   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 <errno.h>
#include <debug.h>
#include <string.h>
#include <limits.h>

#include <nuttx/drivers/pwm.h>
#include <arch/board/board.h>

#include "chip.h"
#include "up_arch.h"
#include "stm32_pwm.h"
#include "omnibusf4.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: stm32_pwm_setup
 *
 * Description:
 *
 *   Initialize PWM and register Omnibus F4's TIM2 and TIM3 PWM devices:
 *
 *    TIM3 CH3 PB0 S1_OUT
 *    TIM3 CH4 PB1 S2_OUT
 *    TIM2 CH4 PA3 S3_OUT
 *    TIM2 CH3 PA2 S4_OUT
 *
 ****************************************************************************/

int stm32_pwm_setup(void)
{
  int npwm = 0;                       /* hardware device enumerator */
  const char *ppwm = NULL;            /* pointer to PWM device name */
  struct pwm_lowerhalf_s *pwm = NULL; /* lower-half driver handle */

  /* Initialize TIM2 and TIM3.
   *
   * Ihe underlying STM32 driver "knows" there are up to four channels
   * available for each timer device, so we don't have to do anything
   * special here to export the two channels each that we're
   * interested in. The user will want to avoid the channels that
   * aren't connected to anything, however, or risk death by boredom
   * from resulting non-response.
   */

  for (npwm = 2; npwm <= 3; npwm++)
    {
      pwm = stm32_pwminitialize(npwm);

      /* If we can't get the lower-half handle, skip and keep going. */

      if (!pwm)
        {
        continue;
        }

      /* Translate the peripheral number to a device name. */

      switch (npwm)
      {
        case 2:
          ppwm = "/dev/pwm2";
          break;

        case 3:
          ppwm = "/dev/pwm3";
          break;

        /* Skip missing names. */

        default:
          continue;
      }

      pwm_register(ppwm, pwm);
    }
  return 0;
}