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-
19  * period
20  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
22  * period
30  * struct pwm_args - board-dependent PWM arguments
31  * @period: reference period
34  * This structure describes board-dependent arguments attached to a PWM
43 	u64 period;  member
53  * struct pwm_waveform - description of a PWM waveform
54  * @period_length_ns: PWM period
56  * @duty_offset_ns: offset of the rising edge from the period's start
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
79  * @period: PWM period (in nanoseconds)
89 	u64 period;  member
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()
148 	return state.period;  in pwm_get_period()
172 	*args = pwm->args;  in pwm_get_args()
176  * pwm_init_state() - prepare a new state to be applied with pwm_apply_might_sleep()
182  * that first retrieves the current PWM state and the replaces the period
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
212  * @scale: target scale of the relative duty cycle
215  * in nanosecond) into a value relative to the period.
223 pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale)  in pwm_get_relative_duty_cycle()  argument
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
236  * @scale: scale in which @duty_cycle is expressed
239  * in nanoseconds), and puts the result in state->duty_cycle.
247  * This functions returns -EINVAL if @duty_cycle and/or @scale are
248  * inconsistent (@scale == 0 or @duty_cycle > @scale).
252 			    unsigned int scale)  in pwm_set_relative_duty_cycle()  argument
254 	if (!scale || duty_cycle > scale)  in pwm_set_relative_duty_cycle()
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()
259 						  scale);  in pwm_set_relative_duty_cycle()
265  * struct pwm_capture - PWM capture data
266  * @period: period of the PWM signal (in nanoseconds)
270 	unsigned int period;  member
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
407 		return -EINVAL;  in pwm_config()
410 		return -EINVAL;  in pwm_config()
413 	if (state.duty_cycle == duty_ns && state.period == period_ns)  in pwm_config()
417 	state.period = period_ns;  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()
610 	 * where the polarity and period are set according to pwm_args info.  in pwm_apply_args()
621 	 * the PWM device and set the reference period and polarity config.  in pwm_apply_args()
630 	state.polarity = pwm->args.polarity;  in pwm_apply_args()
631 	state.period = pwm->args.period;  in pwm_apply_args()
643 	unsigned int period;  member
655 		.period = _period,					\