diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pwm/core.c | 62 |
1 files changed, 51 insertions, 11 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index c6228843a1a7..f1ded8ce5ea4 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -433,24 +433,15 @@ static void pwm_apply_debug(struct pwm_device *pwm, } /** - * pwm_apply_might_sleep() - atomically apply a new state to a PWM device + * __pwm_apply() - atomically apply a new state to a PWM device * @pwm: PWM device * @state: new state to apply */ -int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) +static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state) { struct pwm_chip *chip; int err; - /* - * Some lowlevel driver's implementations of .apply() make use of - * mutexes, also with some drivers only returning when the new - * configuration is active calling pwm_apply_might_sleep() from atomic context - * is a bad idea. So make it explicit that calling this function might - * sleep. - */ - might_sleep(); - if (!pwm || !state || !state->period || state->duty_cycle > state->period) return -EINVAL; @@ -479,9 +470,58 @@ int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) return 0; } + +/** + * pwm_apply_might_sleep() - atomically apply a new state to a PWM device + * Cannot be used in atomic context. + * @pwm: PWM device + * @state: new state to apply + */ +int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) +{ + int err; + + /* + * Some lowlevel driver's implementations of .apply() make use of + * mutexes, also with some drivers only returning when the new + * configuration is active calling pwm_apply_might_sleep() from atomic context + * is a bad idea. So make it explicit that calling this function might + * sleep. + */ + might_sleep(); + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) { + /* + * Catch any drivers that have been marked as atomic but + * that will sleep anyway. + */ + non_block_start(); + err = __pwm_apply(pwm, state); + non_block_end(); + } else { + err = __pwm_apply(pwm, state); + } + + return err; +} EXPORT_SYMBOL_GPL(pwm_apply_might_sleep); /** + * pwm_apply_atomic() - apply a new state to a PWM device from atomic context + * Not all PWM devices support this function, check with pwm_might_sleep(). + * @pwm: PWM device + * @state: new state to apply + */ +int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state) +{ + WARN_ONCE(!pwm->chip->atomic, + "sleeping PWM driver used in atomic context\n"); + + return __pwm_apply(pwm, state); +} +EXPORT_SYMBOL_GPL(pwm_apply_atomic); + +/** * pwm_capture() - capture and report a PWM signal * @pwm: PWM device * @result: structure to fill with capture result |