nuttx/configs/stm32f4discovery/src/stm32_pwm.c
2014-03-20 10:56:43 -06:00

142 lines
4.4 KiB
C

/************************************************************************************
* configs/stm32f4discovery/src/stm32_pwm.c
*
* Copyright (C) 2011 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 <errno.h>
#include <debug.h>
#include <nuttx/pwm.h>
#include <arch/board/board.h>
#include "chip.h"
#include "up_arch.h"
#include "stm32_pwm.h"
#include "stm32f4discovery.h"
/************************************************************************************
* Definitions
************************************************************************************/
/* Configuration *******************************************************************/
/* PWM
*
* The stm32f4discovery has no real on-board PWM devices, but the board can be configured to output
* a pulse train using TIM4 CH2. This pin is used by FSMC is connect to CN5 just for this
* purpose:
*
* PD13 FSMC_A18 / MC_TIM4_CH2OUT pin 33 (EnB)
*
* FSMC must be disabled in this case!
*/
#define HAVE_PWM 1
#ifndef CONFIG_PWM
# undef HAVE_PWM
#endif
#ifndef CONFIG_STM32_TIM4
# undef HAVE_PWM
#endif
#ifndef CONFIG_STM32_TIM4_PWM
# undef HAVE_PWM
#endif
#if CONFIG_STM32_TIM4_CHANNEL != STM32F4DISCOVERY_PWMCHANNEL
# undef HAVE_PWM
#endif
#ifdef HAVE_PWM
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: pwm_devinit
*
* Description:
* All STM32 architectures must provide the following interface to work with
* examples/pwm.
*
************************************************************************************/
int pwm_devinit(void)
{
static bool initialized = false;
struct pwm_lowerhalf_s *pwm;
int ret;
/* Have we already initialized? */
if (!initialized)
{
/* Call stm32_pwminitialize() to get an instance of the PWM interface */
pwm = stm32_pwminitialize(STM32F4DISCOVERY_PWMTIMER);
if (!pwm)
{
dbg("Failed to get the STM32 PWM lower half\n");
return -ENODEV;
}
/* Register the PWM driver at "/dev/pwm0" */
ret = pwm_register("/dev/pwm0", pwm);
if (ret < 0)
{
adbg("pwm_register failed: %d\n", ret);
return ret;
}
/* Now we are initialized */
initialized = true;
}
return OK;
}
#endif /* HAVE_PWM */