1 // SPDX-License-Identifier: GPL-2.0-only
3  * ledtrig-gio.c - LED Trigger Based on GPIO events
19 	struct led_classdev *led;  member
20 	unsigned desired_brightness;	/* desired brightness when led is on */
21 	struct gpio_desc *gpiod;	/* gpio that triggers the led */
26 	struct led_classdev *led = _led;  in gpio_trig_irq()  local
27 	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);  in gpio_trig_irq()
30 	tmp = gpiod_get_value_cansleep(gpio_data->gpiod);  in gpio_trig_irq()
32 		if (gpio_data->desired_brightness)  in gpio_trig_irq()
33 			led_set_brightness_nosleep(gpio_data->led,  in gpio_trig_irq()
34 					   gpio_data->desired_brightness);  in gpio_trig_irq()
36 			led_set_brightness_nosleep(gpio_data->led, LED_FULL);  in gpio_trig_irq()
38 		led_set_brightness_nosleep(gpio_data->led, LED_OFF);  in gpio_trig_irq()
49 	return sysfs_emit(buf, "%u\n", gpio_data->desired_brightness);  in desired_brightness_show()
63 	gpio_data->desired_brightness = desired_brightness;  in desired_brightness_store()
75 static int gpio_trig_activate(struct led_classdev *led)  in gpio_trig_activate()  argument
78 	struct device *dev = led->dev;  in gpio_trig_activate()
83 		return -ENOMEM;  in gpio_trig_activate()
86 	 * The generic property "trigger-sources" is followed,  in gpio_trig_activate()
89 	gpio_data->gpiod = gpiod_get_optional(dev, "trigger-sources", GPIOD_IN);  in gpio_trig_activate()
90 	if (IS_ERR(gpio_data->gpiod)) {  in gpio_trig_activate()
91 		ret = PTR_ERR(gpio_data->gpiod);  in gpio_trig_activate()
95 	if (!gpio_data->gpiod) {  in gpio_trig_activate()
98 		return -EINVAL;  in gpio_trig_activate()
101 	gpiod_set_consumer_name(gpio_data->gpiod, "led-trigger");  in gpio_trig_activate()
103 	gpio_data->led = led;  in gpio_trig_activate()
104 	led_set_trigger_data(led, gpio_data);  in gpio_trig_activate()
106 	ret = request_threaded_irq(gpiod_to_irq(gpio_data->gpiod), NULL, gpio_trig_irq,  in gpio_trig_activate()
108 			| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);  in gpio_trig_activate()
111 		gpiod_put(gpio_data->gpiod);  in gpio_trig_activate()
116 	/* Finally update the LED to initial status */  in gpio_trig_activate()
117 	gpio_trig_irq(0, led);  in gpio_trig_activate()
122 static void gpio_trig_deactivate(struct led_classdev *led)  in gpio_trig_deactivate()  argument
124 	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);  in gpio_trig_deactivate()
126 	free_irq(gpiod_to_irq(gpio_data->gpiod), led);  in gpio_trig_deactivate()
127 	gpiod_put(gpio_data->gpiod);  in gpio_trig_deactivate()
140 MODULE_DESCRIPTION("GPIO LED trigger");