1 /* SPDX-License-Identifier: GPL-2.0 */
15  * enum pwm_polarity - polarity of a PWM signal
16  * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
17  * cycle, followed by a low signal for the remainder of the pulse
19  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
20  * cycle, followed by a high signal for the remainder of the pulse
29  * struct pwm_args - board-dependent PWM arguments
33  * This structure describes board-dependent arguments attached to a PWM
52  * struct pwm_state - state of a PWM channel
54  * @duty_cycle: PWM duty cycle (in nanoseconds)
66  * struct pwm_device - PWM channel object
69  * @hwpwm: per-chip relative index of the PWM device
72  * @chip_data: chip-private data associated with the PWM device
91  * pwm_get_state() - retrieve the current PWM state
98 	*state = pwm->state;  in pwm_get_state()
113 		pwm->state.period = period;  in pwm_set_period()
125 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)  in pwm_set_duty_cycle()  argument
128 		pwm->state.duty_cycle = duty;  in pwm_set_duty_cycle()
152 	*args = pwm->args;  in pwm_get_args()
156  * pwm_init_state() - prepare a new state to be applied with pwm_apply_state()
163  * and polarity fields with the reference values defined in pwm->args.
164  * Once the function returns, you can adjust the ->enabled and ->duty_cycle
167  * ->duty_cycle is initially set to zero to avoid cases where the current
168  * ->duty_cycle value exceed the pwm_args->period one, which would trigger
169  * an error if the user calls pwm_apply_state() without adjusting ->duty_cycle
183 	state->period = args.period;  in pwm_init_state()
184 	state->polarity = args.polarity;  in pwm_init_state()
185 	state->duty_cycle = 0;  in pwm_init_state()
189  * pwm_get_relative_duty_cycle() - Get a relative duty cycle value
190  * @state: PWM state to extract the duty cycle from
191  * @scale: target scale of the relative duty cycle
193  * This functions converts the absolute duty cycle stored in @state (expressed
199  * duty = pwm_get_relative_duty_cycle(&state, 100);
204 	if (!state->period)  in pwm_get_relative_duty_cycle()
207 	return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale,  in pwm_get_relative_duty_cycle()
208 				     state->period);  in pwm_get_relative_duty_cycle()
212  * pwm_set_relative_duty_cycle() - Set a relative duty cycle value
214  * @duty_cycle: relative duty cycle value
217  * This functions converts a relative into an absolute duty cycle (expressed
218  * in nanoseconds), and puts the result in state->duty_cycle.
220  * For example if you want to configure a 50% duty cycle, call:
226  * This functions returns -EINVAL if @duty_cycle and/or @scale are
234 		return -EINVAL;  in pwm_set_relative_duty_cycle()
236 	state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *  in pwm_set_relative_duty_cycle()
237 						  state->period,  in pwm_set_relative_duty_cycle()
244  * struct pwm_ops - PWM controller operations
253  * @config: configure duty cycles and period length for this PWM
279  * struct pwm_chip - abstract a PWM controller
305  * struct pwm_capture - PWM capture data
307  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
322  * pwm_config() - change a PWM device configuration
325  * @period_ns: duration (in nanoseconds) of one cycle
335 		return -EINVAL;  in pwm_config()
338 		return -EINVAL;  in pwm_config()
350  * pwm_enable() - start a PWM output toggling
360 		return -EINVAL;  in pwm_enable()
371  * pwm_disable() - stop a PWM output toggling
421 	return ERR_PTR(-ENODEV);  in pwm_request()
431 	return -ENOTSUPP;  in pwm_apply_state()
436 	return -ENOTSUPP;  in pwm_adjust_config()
442 	return -EINVAL;  in pwm_config()
449 	return -EINVAL;  in pwm_capture()
454 	return -EINVAL;  in pwm_enable()
463 	return -EINVAL;  in pwm_set_chip_data()
473 	return -EINVAL;  in pwmchip_add()
478 	return -EINVAL;  in pwmchip_add_inversed()
483 	return -EINVAL;  in pwmchip_remove()
490 	return ERR_PTR(-ENODEV);  in pwm_request_from_chip()
496 	return ERR_PTR(-ENODEV);  in pwm_get()
503 	return ERR_PTR(-ENODEV);  in of_pwm_get()
513 	return ERR_PTR(-ENODEV);  in devm_pwm_get()
520 	return ERR_PTR(-ENODEV);  in devm_of_pwm_get()
527 	return ERR_PTR(-ENODEV);  in devm_fwnode_pwm_get()
561 	state.polarity = pwm->args.polarity;  in pwm_apply_args()
562 	state.period = pwm->args.period;  in pwm_apply_args()