1 // SPDX-License-Identifier: GPL-2.0-only
3  * linux/drivers/leds-pwm.c
9  * based on leds-gpio.c by Raphael Assenat <raph@8d.com>
42 		       enum led_brightness brightness)  in led_pwm_set()  argument
46 	unsigned int max = led_dat->cdev.max_brightness;  in led_pwm_set()
47 	unsigned long long duty = led_dat->pwmstate.period;  in led_pwm_set()
49 	duty *= brightness;  in led_pwm_set()
52 	if (led_dat->active_low)  in led_pwm_set()
53 		duty = led_dat->pwmstate.period - duty;  in led_pwm_set()
55 	led_dat->pwmstate.duty_cycle = duty;  in led_pwm_set()
57 	 * Disabling a PWM doesn't guarantee that it emits the inactive level.  in led_pwm_set()
62 	led_dat->pwmstate.enabled = !(led_cdev->flags & LED_SUSPENDED);  in led_pwm_set()
63 	return pwm_apply_might_sleep(led_dat->pwm, &led_dat->pwmstate);  in led_pwm_set()
70 	struct led_pwm_data *led_data = &priv->leds[priv->num_leds];  in led_pwm_add()
74 	led_data->active_low = led->active_low;  in led_pwm_add()
75 	led_data->cdev.name = led->name;  in led_pwm_add()
76 	led_data->cdev.brightness = LED_OFF;  in led_pwm_add()
77 	led_data->cdev.max_brightness = led->max_brightness;  in led_pwm_add()
78 	led_data->cdev.flags = LED_CORE_SUSPENDRESUME;  in led_pwm_add()
80 	led_data->pwm = devm_fwnode_pwm_get(dev, fwnode, NULL);  in led_pwm_add()
81 	if (IS_ERR(led_data->pwm))  in led_pwm_add()
82 		return dev_err_probe(dev, PTR_ERR(led_data->pwm),  in led_pwm_add()
84 				     led->name);  in led_pwm_add()
86 	led_data->cdev.brightness_set_blocking = led_pwm_set;  in led_pwm_add()
89 	switch (led->default_state) {  in led_pwm_add()
91 		pwm_get_state(led_data->pwm, &led_data->pwmstate);  in led_pwm_add()
92 		if (led_data->pwmstate.period)  in led_pwm_add()
94 		led->default_state = LEDS_DEFSTATE_OFF;  in led_pwm_add()
96 			"failed to read period for %s, default to off",  in led_pwm_add()
97 			led->name);  in led_pwm_add()
99 	default:  in led_pwm_add()
100 		pwm_init_state(led_data->pwm, &led_data->pwmstate);  in led_pwm_add()
104 	/* set brightness */  in led_pwm_add()
105 	switch (led->default_state) {  in led_pwm_add()
107 		led_data->cdev.brightness = led->max_brightness;  in led_pwm_add()
111 		uint64_t brightness;  in led_pwm_add()  local
113 		brightness = led->max_brightness;  in led_pwm_add()
114 		brightness *= led_data->pwmstate.duty_cycle;  in led_pwm_add()
115 		do_div(brightness, led_data->pwmstate.period);  in led_pwm_add()
116 		led_data->cdev.brightness = brightness;  in led_pwm_add()
121 	ret = devm_led_classdev_register_ext(dev, &led_data->cdev, &init_data);  in led_pwm_add()
124 			led->name, ret);  in led_pwm_add()
128 	if (led->default_state != LEDS_DEFSTATE_KEEP) {  in led_pwm_add()
129 		ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);  in led_pwm_add()
132 				led->name, ret);  in led_pwm_add()
137 	priv->num_leds++;  in led_pwm_add()
152 			led.name = to_of_node(fwnode)->name;  in led_pwm_create_fwnode()
155 			ret = -EINVAL;  in led_pwm_create_fwnode()
160 							   "active-low");  in led_pwm_create_fwnode()
161 		fwnode_property_read_u32(fwnode, "max-brightness",  in led_pwm_create_fwnode()
184 	count = device_get_child_node_count(&pdev->dev);  in led_pwm_probe()
187 		return -EINVAL;  in led_pwm_probe()
189 	priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),  in led_pwm_probe()
192 		return -ENOMEM;  in led_pwm_probe()
194 	ret = led_pwm_create_fwnode(&pdev->dev, priv);  in led_pwm_probe()
205 	{ .compatible = "pwm-leds", },
223 MODULE_ALIAS("platform:leds-pwm");