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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file pwm.h
* @brief PWM Driver macros and structures.
*
* @addtogroup PWM
* @{
*/
#ifndef _PWM_H_
#define _PWM_H_
#if HAL_USE_PWM || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver data structures and types. */
/*===========================================================================*/
/**
* @brief Driver state machine possible states.
*/
typedef enum {
PWM_UNINIT = 0, /**< Not initialized. */
PWM_STOP = 1, /**< Stopped. */
PWM_READY = 2, /**< Ready. */
} pwmstate_t;
/**
* @brief Type of a structure representing a PWM driver.
*/
typedef struct PWMDriver PWMDriver;
/**
* @brief PWM notification callback type.
*
* @param[in] pwmp pointer to a @p PWMDriver object
*/
typedef void (*pwmcallback_t)(PWMDriver *pwmp);
#include "pwm_lld.h"
/*===========================================================================*/
/* Driver macros. */
/*===========================================================================*/
/**
* @brief Converts from fraction to pulse width.
* @note Be careful with rounding errors, this is integer math not magic.
* You can specify tenths of thousandth but make sure you have the
* proper hardware resolution by carefully choosing the clock source
* and prescaler settings, see @p PWM_COMPUTE_PSC.
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] denominator denominator of the fraction
* @param[in] numerator numerator of the fraction
* @return The pulse width to be passed to @p pwmEnableChannel().
*
* @api
*/
#define PWM_FRACTION_TO_WIDTH(pwmp, denominator, numerator) \
((uint16_t)((((uint32_t)(pwmp)->period) * \
(uint32_t)(numerator)) / (uint32_t)(denominator)))
/**
* @brief Converts from degrees to pulse width.
* @note Be careful with rounding errors, this is integer math not magic.
* You can specify hundredths of degrees but make sure you have the
* proper hardware resolution by carefully choosing the clock source
* and prescaler settings, see @p PWM_COMPUTE_PSC.
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] degrees degrees as an integer between 0 and 36000
* @return The pulse width to be passed to @p pwmEnableChannel().
*
* @api
*/
#define PWM_DEGREES_TO_WIDTH(pwmp, degrees) \
PWM_FRACTION_TO_WIDTH(pwmp, 36000, degrees)
/**
* @brief Converts from percentage to pulse width.
* @note Be careful with rounding errors, this is integer math not magic.
* You can specify tenths of thousandth but make sure you have the
* proper hardware resolution by carefully choosing the clock source
* and prescaler settings, see @p PWM_COMPUTE_PSC.
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] percentage percentage as an integer between 0 and 10000
* @return The pulse width to be passed to @p pwmEnableChannel().
*
* @api
*/
#define PWM_PERCENTAGE_TO_WIDTH(pwmp, percentage) \
PWM_FRACTION_TO_WIDTH(pwmp, 10000, percentage)
/**
* @brief Changes the period the PWM peripheral.
* @details This function changes the period of a PWM unit that has already
* been activated using @p pwmStart().
* @pre The PWM unit must have been activated using @p pwmStart().
* @post The PWM unit period is changed to the new value.
* @post Any active channel is disabled by this function and must be
* activated explicitly using @p pwmEnableChannel().
* @note Depending on the hardware implementation this function has
* effect starting on the next cycle (recommended implementation)
* or immediately (fallback implementation).
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] period new cycle time in ticks
*
* @iclass
*/
#define pwmChangePeriodI(pwmp, period) { \
(pwmp)->period = (period); \
pwm_lld_change_period(pwmp, period); \
}
/**
* @brief Enables a PWM channel.
* @pre The PWM unit must have been activated using @p pwmStart().
* @post The channel is active using the specified configuration.
* @note Depending on the hardware implementation this function has
* effect starting on the next cycle (recommended implementation)
* or immediately (fallback implementation).
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
* @param[in] width PWM pulse width as clock pulses number
*
* @iclass
*/
#define pwmEnableChannelI(pwmp, channel, width) \
pwm_lld_enable_channel(pwmp, channel, width)
/**
* @brief Disables a PWM channel.
* @pre The PWM unit must have been activated using @p pwmStart().
* @post The channel is disabled and its output line returned to the
* idle state.
* @note Depending on the hardware implementation this function has
* effect starting on the next cycle (recommended implementation)
* or immediately (fallback implementation).
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
*
* @iclass
*/
#define pwmDisableChannelI(pwmp, channel) \
pwm_lld_disable_channel(pwmp, channel)
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#ifdef __cplusplus
extern "C" {
#endif
void pwmInit(void);
void pwmObjectInit(PWMDriver *pwmp);
void pwmStart(PWMDriver *pwmp, const PWMConfig *config);
void pwmStop(PWMDriver *pwmp);
void pwmChangePeriod(PWMDriver *pwmp, pwmcnt_t period);
void pwmEnableChannel(PWMDriver *pwmp,
pwmchannel_t channel,
pwmcnt_t width);
void pwmDisableChannel(PWMDriver *pwmp, pwmchannel_t channel);
#ifdef __cplusplus
}
#endif
#endif /* HAL_USE_PWM */
#endif /* _PWM_H_ */
/** @} */
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