diff options
| -rw-r--r-- | Documentation/driver-api/pwm.rst | 6 | ||||
| -rw-r--r-- | include/linux/pwm.h | 5 |
2 files changed, 10 insertions, 1 deletions
diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index ab62f1bb0366..381f3c46cdac 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -55,7 +55,11 @@ several parameter at once. For example, if you see pwm_config() and pwm_{enable,disable}() calls in the same function, this probably means you should switch to pwm_apply_state(). -The PWM user API also allows one to query the PWM state with pwm_get_state(). +The PWM user API also allows one to query the last applied PWM state with +pwm_get_last_applied_state(). Note this is different to what the driver has +actually implemented if the request cannot be implemented exactly with the +hardware in use. There is currently no way for consumers to get the actually +implemented settings. In addition to the PWM state, the PWM API also exposes PWM arguments, which are the reference PWM config one should use on this PWM. diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 8f4eefd129aa..5bb90af4997e 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -91,6 +91,11 @@ struct pwm_device { * pwm_get_state() - retrieve the current PWM state * @pwm: PWM device * @state: state to fill with the current PWM state + * + * The returned PWM state represents the state that was applied by a previous call to + * pwm_apply_state(). Drivers may have to slightly tweak that state before programming it to + * hardware. If pwm_apply_state() was never called, this returns either the current hardware + * state (if supported) or the default settings. */ static inline void pwm_get_state(const struct pwm_device *pwm, struct pwm_state *state) |