1 /* SPDX-License-Identifier: GPL-2.0 */
12  * enum pwm_polarity - polarity of a PWM signal
13  * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
14  * cycle, followed by a low signal for the remainder of the pulse
16  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
17  * cycle, followed by a high signal for the remainder of the pulse
26  * struct pwm_args - board-dependent PWM arguments
30  * This structure describes board-dependent arguments attached to a PWM
49  * struct pwm_state - state of a PWM channel
51  * @duty_cycle: PWM duty cycle (in nanoseconds)
68  * struct pwm_device - PWM channel object
71  * @hwpwm: per-chip relative index of the PWM device
74  * @chip_data: chip-private data associated with the PWM device
93  * pwm_get_state() - retrieve the current PWM state
105 	*state = pwm->state;  in pwm_get_state()
120 		pwm->state.period = period;  in pwm_set_period()
132 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)  in pwm_set_duty_cycle()  argument
135 		pwm->state.duty_cycle = duty;  in pwm_set_duty_cycle()
159 	*args = pwm->args;  in pwm_get_args()
163  * pwm_init_state() - prepare a new state to be applied with pwm_apply_state()
170  * and polarity fields with the reference values defined in pwm->args.
171  * Once the function returns, you can adjust the ->enabled and ->duty_cycle
174  * ->duty_cycle is initially set to zero to avoid cases where the current
175  * ->duty_cycle value exceed the pwm_args->period one, which would trigger
176  * an error if the user calls pwm_apply_state() without adjusting ->duty_cycle
190 	state->period = args.period;  in pwm_init_state()
191 	state->polarity = args.polarity;  in pwm_init_state()
192 	state->duty_cycle = 0;  in pwm_init_state()
193 	state->usage_power = false;  in pwm_init_state()
197  * pwm_get_relative_duty_cycle() - Get a relative duty cycle value
198  * @state: PWM state to extract the duty cycle from
199  * @scale: target scale of the relative duty cycle
201  * This functions converts the absolute duty cycle stored in @state (expressed
207  * duty = pwm_get_relative_duty_cycle(&state, 100);
212 	if (!state->period)  in pwm_get_relative_duty_cycle()
215 	return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale,  in pwm_get_relative_duty_cycle()
216 				     state->period);  in pwm_get_relative_duty_cycle()
220  * pwm_set_relative_duty_cycle() - Set a relative duty cycle value
222  * @duty_cycle: relative duty cycle value
225  * This functions converts a relative into an absolute duty cycle (expressed
226  * in nanoseconds), and puts the result in state->duty_cycle.
228  * For example if you want to configure a 50% duty cycle, call:
234  * This functions returns -EINVAL if @duty_cycle and/or @scale are
242 		return -EINVAL;  in pwm_set_relative_duty_cycle()
244 	state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *  in pwm_set_relative_duty_cycle()
245 						  state->period,  in pwm_set_relative_duty_cycle()
252  * struct pwm_capture - PWM capture data
254  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
262  * struct pwm_ops - PWM controller operations
285  * struct pwm_chip - abstract a PWM controller
316  * pwm_config() - change a PWM device configuration
319  * @period_ns: duration (in nanoseconds) of one cycle
329 		return -EINVAL;  in pwm_config()
332 		return -EINVAL;  in pwm_config()
344  * pwm_enable() - start a PWM output toggling
354 		return -EINVAL;  in pwm_enable()
365  * pwm_disable() - stop a PWM output toggling
415 	return -ENOTSUPP;  in pwm_apply_state()
420 	return -ENOTSUPP;  in pwm_adjust_config()
427 	return -EINVAL;  in pwm_config()
433 	return -EINVAL;  in pwm_enable()
445 	return -EINVAL;  in pwm_capture()
450 	return -EINVAL;  in pwm_set_chip_data()
460 	return -EINVAL;  in pwmchip_add()
465 	return -EINVAL;  in pwmchip_remove()
470 	return -EINVAL;  in devm_pwmchip_add()
478 	return ERR_PTR(-ENODEV);  in pwm_request_from_chip()
485 	return ERR_PTR(-ENODEV);  in pwm_get()
497 	return ERR_PTR(-ENODEV);  in devm_pwm_get()
505 	return ERR_PTR(-ENODEV);  in devm_fwnode_pwm_get()
535 	state.polarity = pwm->args.polarity;  in pwm_apply_args()
536 	state.period = pwm->args.period;  in pwm_apply_args()