OpenModem/bertos/drv/pwm.h

179 lines
5.2 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos 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 2 of the License, or
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* This program 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
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* Copyright 2005 Develer S.r.l. (http://www.develer.com/)
* -->
* \defgroup pwm_driver PWM driver
* \ingroup drivers
* \{
* \brief Pulse Width Modulation (PWM) driver.
*
* \author Francesco Sacchi <batt@develer.com>
* \author Daniele Basile <asterix@develer.com>
*
* $WIZ$ module_name = "pwm"
* $WIZ$ module_configuration = "bertos/cfg/cfg_pwm.h"
* $WIZ$ module_hw = "bertos/hw/pwm_map.h"
* $WIZ$ module_supports = "not avr and not cm3"
*/
#ifndef DRV_PWM_H
#define DRV_PWM_H
#include <cpu/attr.h>
#include <cfg/compiler.h>
#include "cfg/cfg_pwm.h"
/**
* Maximum PWM duty cycle value (100%)
*/
#define PWM_MAX_DUTY ((pwm_duty_t)0xFFFF)
#define PWM_MAX_PERIOD 0xFFFF
#define PWM_MAX_PERIOD_LOG2 16
/**
* Type for PWM duty cycle.
* The value is represented as a 16bit unsigned integer, so it ranges from 0 (0%)
* to PWM_MAX_DUTY (0xFFFF = 100%).
*/
typedef uint16_t pwm_duty_t;
/**
* Type for PWM frequency.
* Unit of measure is Hz.
*/
typedef uint32_t pwm_freq_t;
#if !CFG_PWM_ENABLE_OLD_API || defined(__doxygen__)
/**
* \defgroup pwm_api PWM API
* With this driver you can control a device with multiple PWM channels.
* You can enable/disable each channel indipendently and also set frequency
* and duty cycle.
*
* API usage example:
* \code
* Pwm pwm; // declare a context structure
* pwm_init(&pwm, 0); // init pwm channel 0
* pwm_setFrequency(&pwm, 1000); // Set frequency of channel 0 to 1000Hz
* pwm_setDuty(&pwm, 0x7FFF); // Set duty to 50% (0xFFFF/2)
* pwm_enable(&pwm, true); // Activate the output
* \endcode
* \{
*/
/**
* Enum describing PWM polarities.
*/
typedef enum PwmPolarity
{
/** High pulse: increasing duty increases the part of the signal at high level. */
PWM_POL_HIGH_PULSE,
/** Positive pulse: same as High pulse. */
PWM_POL_POSITIVE = PWM_POL_HIGH_PULSE,
/** Low pulse: increasing duty increases the part of the signal at low level. */
PWM_POL_LOW_PULSE,
/** Negative pulse: same as Low pulse. */
PWM_POL_NEGATIVE = PWM_POL_LOW_PULSE,
} PwmPolarity;
struct PwmHardware; //Fwd declaration
/**
* PWM context structure.
*/
typedef struct Pwm
{
unsigned ch;
pwm_duty_t duty;
PwmPolarity pol;
bool enabled;
struct PwmHardware *hw;
} Pwm;
void pwm_setDuty(Pwm *ctx, pwm_duty_t duty);
void pwm_setFrequency(Pwm *ctx, pwm_freq_t freq);
void pwm_setPolarity(Pwm *ctx, PwmPolarity pol);
void pwm_enable(Pwm *ctx, bool state);
void pwm_init(Pwm *ctx, unsigned channel);
/** \} */ //defgroup pwm_api
#endif
#if CFG_PWM_ENABLE_OLD_API
/**
* \defgroup pwm_old_api Old PWM API
* This API has strong limititations, so it has been deprecated.
* It is active by default for backward compatibility reasons, but
* for new projects please use the new PWM API.
* In order to disable this API, check CFG_PWM_ENABLE_OLD_API.
* \see pwm_api
* \see CFG_PWM_ENABLE_OLD_API
* \{
*/
#include CPU_HEADER(pwm)
#include "hw/pwm_map.h"
/**
* Set PWM polarity of pwm \p dev.
* \param dev PWM channel.
* \param pol if false positive polarity pulses are generated,
* if true negative polarity pulses are generated.
* \warning This function has to be called with PWM disabled, otherwise
* the output value will be undefined.
*/
INLINE void pwm_setPolarity(PwmDev dev, bool pol)
{
pwm_hw_setPolarity(dev, pol);
}
void pwm_setDuty(PwmDev dev, pwm_duty_t duty);
void pwm_setFrequency(PwmDev dev, pwm_freq_t freq);
void pwm_enable(PwmDev dev, bool state);
void pwm_init(void);
/** \} */ //defgroup pwm_old_api
#endif
/*
* Test function prototypes.
*
* See pwm_test.c for implemntation of these functions.
*/
void pwm_testRun(void);
int pwm_testSetup(void);
/* For backward compatibility */
#define pwm_testSetUp() pwm_testSetup()
int pwm_testTearDown(void);
/** \} */ //defgroup pwm_driver
#endif /* DRV_PWM_H */