1 /* SPDX-License-Identifier: GPL-2.0 */
16  * enum pwm_polarity - polarity of a PWM signal
17  * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
18  * cycle, followed by a low signal for the remainder of the pulse
20  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
21  * cycle, followed by a high signal for the remainder of the pulse
30  * struct pwm_args - board-dependent PWM arguments
34  * This structure describes board-dependent arguments attached to a PWM
53  * struct pwm_waveform - description of a PWM waveform
55  * @duty_length_ns: PWM duty cycle
61  * PWM_POLARITY_NORMAL) and period - duty_cycle (.polarity =
67  * active or inactive level, go high-z or even continue to toggle.
78  * struct pwm_state - state of a PWM channel
80  * @duty_cycle: PWM duty cycle (in nanoseconds)
97  * struct pwm_device - PWM channel object
100  * @hwpwm: per-chip relative index of the PWM device
118  * pwm_get_state() - retrieve the current PWM state
130 	*state = pwm->state;  in pwm_get_state()
172 	*args = pwm->args;  in pwm_get_args()
176  * pwm_init_state() - prepare a new state to be applied with pwm_apply_might_sleep()
183  * and polarity fields with the reference values defined in pwm->args.
184  * Once the function returns, you can adjust the ->enabled and ->duty_cycle
187  * ->duty_cycle is initially set to zero to avoid cases where the current
188  * ->duty_cycle value exceed the pwm_args->period one, which would trigger
189  * an error if the user calls pwm_apply_might_sleep() without adjusting ->duty_cycle
203 	state->period = args.period;  in pwm_init_state()
204 	state->polarity = args.polarity;  in pwm_init_state()
205 	state->duty_cycle = 0;  in pwm_init_state()
206 	state->usage_power = false;  in pwm_init_state()
210  * pwm_get_relative_duty_cycle() - Get a relative duty cycle value
211  * @state: PWM state to extract the duty cycle from
212  * @scale: target scale of the relative duty cycle
214  * This functions converts the absolute duty cycle stored in @state (expressed
220  * duty = pwm_get_relative_duty_cycle(&state, 100);
225 	if (!state->period)  in pwm_get_relative_duty_cycle()
228 	return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale,  in pwm_get_relative_duty_cycle()
229 				     state->period);  in pwm_get_relative_duty_cycle()
233  * pwm_set_relative_duty_cycle() - Set a relative duty cycle value
235  * @duty_cycle: relative duty cycle value
238  * This functions converts a relative into an absolute duty cycle (expressed
239  * in nanoseconds), and puts the result in state->duty_cycle.
241  * For example if you want to configure a 50% duty cycle, call:
247  * This functions returns -EINVAL if @duty_cycle and/or @scale are
255 		return -EINVAL;  in pwm_set_relative_duty_cycle()
257 	state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *  in pwm_set_relative_duty_cycle()
258 						  state->period,  in pwm_set_relative_duty_cycle()
265  * struct pwm_capture - PWM capture data
267  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
275  * struct pwm_ops - PWM controller operations
310  * struct pwm_chip - abstract a PWM controller
317  * @atomic: can the driver's ->apply() be called in atomic context
351  * pwmchip_supports_waveform() - checks if the given chip supports waveform callbacks
364 	return chip->ops->write_waveform != NULL;  in pwmchip_supports_waveform()
369 	return chip->dev.parent;  in pwmchip_parent()
374 	return dev_get_drvdata(&chip->dev);  in pwmchip_get_drvdata()
379 	dev_set_drvdata(&chip->dev, data);  in pwmchip_set_drvdata()
394  * pwm_config() - change a PWM device configuration
397  * @period_ns: duration (in nanoseconds) of one cycle
407 		return -EINVAL;  in pwm_config()
410 		return -EINVAL;  in pwm_config()
422  * pwm_enable() - start a PWM output toggling
432 		return -EINVAL;  in pwm_enable()
443  * pwm_disable() - stop a PWM output toggling
462  * pwm_might_sleep() - is pwm_apply_atomic() supported?
469 	return !pwm->chip->atomic;  in pwm_might_sleep()
506 	return -EOPNOTSUPP;  in pwm_apply_might_sleep()
512 	return -EOPNOTSUPP;  in pwm_apply_atomic()
517 	return -EOPNOTSUPP;  in pwm_get_state_hw()
522 	return -EOPNOTSUPP;  in pwm_adjust_config()
529 	return -EINVAL;  in pwm_config()
535 	return -EINVAL;  in pwm_enable()
551 	return ERR_PTR(-EINVAL);  in pwmchip_alloc()
563 	return -EINVAL;  in pwmchip_add()
568 	return -EINVAL;  in pwmchip_remove()
573 	return -EINVAL;  in devm_pwmchip_add()
580 	return ERR_PTR(-ENODEV);  in pwm_get()
592 	return ERR_PTR(-ENODEV);  in devm_pwm_get()
600 	return ERR_PTR(-ENODEV);  in devm_fwnode_pwm_get()
630 	state.polarity = pwm->args.polarity;  in pwm_apply_args()
631 	state.period = pwm->args.period;  in pwm_apply_args()