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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __PWM_H
#define __PWM_H
#include <dt-bindings/pwm/pwm.h>
#include <errno.h>
struct pwm_device;
struct device_d;
#define PWM_POLARITY_NORMAL 0
/*
* struct pwm_state - state of a PWM channel
* @period_ns: PWM period (in nanoseconds)
* @duty_ns: PWM duty cycle (in nanoseconds)
* @polarity: PWM polarity
* @p_enable: PWM enabled status
*/
struct pwm_state {
unsigned int period_ns;
unsigned int duty_ns;
unsigned int polarity;
unsigned int p_enable;
};
/*
* pwm_request - request a PWM device
*/
struct pwm_device *pwm_request(const char *pwmname);
struct pwm_device *of_pwm_request(struct device_node *np, const char *con_id);
/*
* pwm_free - free a PWM device
*/
void pwm_free(struct pwm_device *pwm);
/*
* pwm_init_state - prepare a new state from device tree args
*/
void pwm_init_state(const struct pwm_device *pwm,
struct pwm_state *state);
/*
* pwm_config - change a PWM device configuration
*/
int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state);
/*
* pwm_config - change a PWM device configuration
*/
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
/*
* pwm_enable - start a PWM output toggling
*/
int pwm_enable(struct pwm_device *pwm);
/*
* pwm_disable - stop a PWM output toggling
*/
void pwm_disable(struct pwm_device *pwm);
unsigned int pwm_get_period(struct pwm_device *pwm);
/**
* pwm_set_relative_duty_cycle() - Set a relative duty cycle value
* @state: PWM state to fill
* @duty_cycle: relative duty cycle value
* @scale: scale in which @duty_cycle is expressed
*
* This functions converts a relative into an absolute duty cycle (expressed
* in nanoseconds), and puts the result in state->duty_cycle.
*
* For example if you want to configure a 50% duty cycle, call:
*
* pwm_init_state(pwm, &state);
* pwm_set_relative_duty_cycle(&state, 50, 100);
* pwm_apply_state(pwm, &state);
*
* This functions returns -EINVAL if @duty_cycle and/or @scale are
* inconsistent (@scale == 0 or @duty_cycle > @scale).
*/
static inline int
pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle,
unsigned int scale)
{
if (!scale || duty_cycle > scale)
return -EINVAL;
state->duty_ns = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *
state->period_ns,
scale);
return 0;
}
struct pwm_chip;
/**
* pwm_get_state() - retrieve the current PWM state
* @pwm: PWM device
* @state: state to fill with the current PWM state
*/
void pwm_get_state(const struct pwm_device *pwm, struct pwm_state *state);
/**
* pwm_apply_state() - apply the passed PWM state
* @pwm: PWM device
* @state: state to apply to pwm device
*/
int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state);
/**
* struct pwm_ops - PWM operations
* @request: optional hook for requesting a PWM
* @free: optional hook for freeing a PWM
* @apply: apply specified pwm state
*/
struct pwm_ops {
int (*request)(struct pwm_chip *chip);
void (*free)(struct pwm_chip *chip);
int (*apply)(struct pwm_chip *chip, const struct pwm_state *state);
};
/**
* struct pwm_chip - abstract a PWM
* @id: The id of this pwm
* @devname: unique identifier for this pwm
* @ops: The callbacks for this PWM
* @state: current state of the PWM
*/
struct pwm_chip {
int id;
const char *devname;
const struct pwm_ops *ops;
struct pwm_state state;
};
int pwmchip_add(struct pwm_chip *chip, struct device_d *dev);
int pwmchip_remove(struct pwm_chip *chip);
#endif /* __PWM_H */
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