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pwm: Introduce the pwm_state concept

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The PWM state, represented by its period, duty_cycle and polarity is
currently directly stored in the PWM device. Declare a pwm_state
structure embedding those field so that we can later use this struct
to atomically update all the PWM parameters at once.

All pwm_get_xxx() helpers are now implemented as wrappers around
pwm_get_state().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Boris Brezillon 2016-04-14 21:17:38 +02:00 committed by Thierry Reding
parent a8c3862551
commit 43a276b003
2 changed files with 46 additions and 16 deletions
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8
drivers/pwm/core.c
View File

@ -268,7 +268,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
pwm->chip = chip;
pwm->pwm = chip->base + i;
pwm->hwpwm = i;
pwm->polarity = polarity;
pwm->state.polarity = polarity;
radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
}
@ -446,8 +446,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
if (err)
return err;
pwm->duty_cycle = duty_ns;
pwm->period = period_ns;
pwm->state.duty_cycle = duty_ns;
pwm->state.period = period_ns;
return 0;
}
@ -480,7 +480,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
if (err)
return err;
pwm->polarity = polarity;
pwm->state.polarity = polarity;
return 0;
}

54
include/linux/pwm.h
View File

@ -98,6 +98,18 @@ enum {
PWMF_EXPORTED = 1 << 2,
};
/*
* struct pwm_state - state of a PWM channel
* @period: PWM period (in nanoseconds)
* @duty_cycle: PWM duty cycle (in nanoseconds)
* @polarity: PWM polarity
*/
struct pwm_state {
unsigned int period;
unsigned int duty_cycle;
enum pwm_polarity polarity;
};
/**
* struct pwm_device - PWM channel object
* @label: name of the PWM device
@ -106,10 +118,8 @@ enum {
* @pwm: global index of the PWM device
* @chip: PWM chip providing this PWM device
* @chip_data: chip-private data associated with the PWM device
* @period: period of the PWM signal (in nanoseconds)
* @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
* @polarity: polarity of the PWM signal
* @args: PWM arguments
* @state: curent PWM channel state
*/
struct pwm_device {
const char *label;
@ -119,13 +129,21 @@ struct pwm_device {
struct pwm_chip *chip;
void *chip_data;
unsigned int period;
unsigned int duty_cycle;
enum pwm_polarity polarity;
struct pwm_args args;
struct pwm_state state;
};
/**
* pwm_get_state() - retrieve the current PWM state
* @pwm: PWM device
* @state: state to fill with the current PWM state
*/
static inline void pwm_get_state(const struct pwm_device *pwm,
struct pwm_state *state)
{
*state = pwm->state;
}
static inline bool pwm_is_enabled(const struct pwm_device *pwm)
{
return test_bit(PWMF_ENABLED, &pwm->flags);
@ -134,23 +152,31 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm)
static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
{
if (pwm)
pwm->period = period;
pwm->state.period = period;
}
static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
{
return pwm ? pwm->period : 0;
struct pwm_state state;
pwm_get_state(pwm, &state);
return state.period;
}
static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
{
if (pwm)
pwm->duty_cycle = duty;
pwm->state.duty_cycle = duty;
}
static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
{
return pwm ? pwm->duty_cycle : 0;
struct pwm_state state;
pwm_get_state(pwm, &state);
return state.duty_cycle;
}
/*
@ -160,7 +186,11 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
{
return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
struct pwm_state state;
pwm_get_state(pwm, &state);
return state.polarity;
}
static inline void pwm_get_args(const struct pwm_device *pwm,