1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * LED Kernel Timer Trigger
4  *
5  * Copyright 2005-2006 Openedhand Ltd.
6  *
7  * Author: Richard Purdie <rpurdie@openedhand.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/device.h>
14 #include <linux/ctype.h>
15 #include <linux/slab.h>
16 #include <linux/leds.h>
17 
18 static ssize_t led_delay_on_show(struct device *dev,
19 		struct device_attribute *attr, char *buf)
20 {
21 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
22 
23 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
24 }
25 
26 static ssize_t led_delay_on_store(struct device *dev,
27 		struct device_attribute *attr, const char *buf, size_t size)
28 {
29 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
30 	unsigned long state;
31 	ssize_t ret = -EINVAL;
32 
33 	ret = kstrtoul(buf, 10, &state);
34 	if (ret)
35 		return ret;
36 
37 	led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
38 	led_cdev->blink_delay_on = state;
39 
40 	return size;
41 }
42 
43 static ssize_t led_delay_off_show(struct device *dev,
44 		struct device_attribute *attr, char *buf)
45 {
46 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
47 
48 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
49 }
50 
51 static ssize_t led_delay_off_store(struct device *dev,
52 		struct device_attribute *attr, const char *buf, size_t size)
53 {
54 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
55 	unsigned long state;
56 	ssize_t ret = -EINVAL;
57 
58 	ret = kstrtoul(buf, 10, &state);
59 	if (ret)
60 		return ret;
61 
62 	led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
63 	led_cdev->blink_delay_off = state;
64 
65 	return size;
66 }
67 
68 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
69 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
70 
71 static struct attribute *timer_trig_attrs[] = {
72 	&dev_attr_delay_on.attr,
73 	&dev_attr_delay_off.attr,
74 	NULL
75 };
76 ATTRIBUTE_GROUPS(timer_trig);
77 
78 static void pattern_init(struct led_classdev *led_cdev)
79 {
80 	u32 *pattern;
81 	unsigned int size = 0;
82 
83 	pattern = led_get_default_pattern(led_cdev, &size);
84 	if (!pattern)
85 		return;
86 
87 	if (size != 2) {
88 		dev_warn(led_cdev->dev,
89 			 "Expected 2 but got %u values for delays pattern\n",
90 			 size);
91 		goto out;
92 	}
93 
94 	led_cdev->blink_delay_on = pattern[0];
95 	led_cdev->blink_delay_off = pattern[1];
96 	/* led_blink_set() called by caller */
97 
98 out:
99 	kfree(pattern);
100 }
101 
102 static int timer_trig_activate(struct led_classdev *led_cdev)
103 {
104 	if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
105 		pattern_init(led_cdev);
106 		/*
107 		 * Mark as initialized even on pattern_init() error because
108 		 * any consecutive call to it would produce the same error.
109 		 */
110 		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
111 	}
112 
113 	/*
114 	 * If "set brightness to 0" is pending in workqueue, we don't
115 	 * want that to be reordered after blink_set()
116 	 */
117 	flush_work(&led_cdev->set_brightness_work);
118 	led_blink_set(led_cdev, &led_cdev->blink_delay_on,
119 		      &led_cdev->blink_delay_off);
120 
121 	return 0;
122 }
123 
124 static void timer_trig_deactivate(struct led_classdev *led_cdev)
125 {
126 	/* Stop blinking */
127 	led_set_brightness(led_cdev, LED_OFF);
128 }
129 
130 static struct led_trigger timer_led_trigger = {
131 	.name     = "timer",
132 	.activate = timer_trig_activate,
133 	.deactivate = timer_trig_deactivate,
134 	.groups = timer_trig_groups,
135 };
136 module_led_trigger(timer_led_trigger);
137 
138 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
139 MODULE_DESCRIPTION("Timer LED trigger");
140 MODULE_LICENSE("GPL v2");
141