1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * One-shot LED Trigger
4  *
5  * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com>
6  *
7  * Based on ledtrig-timer.c by 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 #include "../leds.h"
18 
19 #define DEFAULT_DELAY 100
20 
21 struct oneshot_trig_data {
22 	unsigned int invert;
23 };
24 
led_shot(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)25 static ssize_t led_shot(struct device *dev,
26 		struct device_attribute *attr, const char *buf, size_t size)
27 {
28 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
29 	struct oneshot_trig_data *oneshot_data = led_trigger_get_drvdata(dev);
30 
31 	led_blink_set_oneshot(led_cdev,
32 			&led_cdev->blink_delay_on, &led_cdev->blink_delay_off,
33 			oneshot_data->invert);
34 
35 	/* content is ignored */
36 	return size;
37 }
led_invert_show(struct device * dev,struct device_attribute * attr,char * buf)38 static ssize_t led_invert_show(struct device *dev,
39 		struct device_attribute *attr, char *buf)
40 {
41 	struct oneshot_trig_data *oneshot_data = led_trigger_get_drvdata(dev);
42 
43 	return sprintf(buf, "%u\n", oneshot_data->invert);
44 }
45 
led_invert_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)46 static ssize_t led_invert_store(struct device *dev,
47 		struct device_attribute *attr, const char *buf, size_t size)
48 {
49 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
50 	struct oneshot_trig_data *oneshot_data = led_trigger_get_drvdata(dev);
51 	unsigned long state;
52 	int ret;
53 
54 	ret = kstrtoul(buf, 0, &state);
55 	if (ret)
56 		return ret;
57 
58 	oneshot_data->invert = !!state;
59 
60 	if (oneshot_data->invert)
61 		led_set_brightness_nosleep(led_cdev, LED_FULL);
62 	else
63 		led_set_brightness_nosleep(led_cdev, LED_OFF);
64 
65 	return size;
66 }
67 
led_delay_on_show(struct device * dev,struct device_attribute * attr,char * buf)68 static ssize_t led_delay_on_show(struct device *dev,
69 		struct device_attribute *attr, char *buf)
70 {
71 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
72 
73 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
74 }
75 
led_delay_on_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)76 static ssize_t led_delay_on_store(struct device *dev,
77 		struct device_attribute *attr, const char *buf, size_t size)
78 {
79 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
80 	unsigned long state;
81 	int ret;
82 
83 	ret = kstrtoul(buf, 0, &state);
84 	if (ret)
85 		return ret;
86 
87 	led_cdev->blink_delay_on = state;
88 
89 	return size;
90 }
91 
led_delay_off_show(struct device * dev,struct device_attribute * attr,char * buf)92 static ssize_t led_delay_off_show(struct device *dev,
93 		struct device_attribute *attr, char *buf)
94 {
95 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
96 
97 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
98 }
99 
led_delay_off_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)100 static ssize_t led_delay_off_store(struct device *dev,
101 		struct device_attribute *attr, const char *buf, size_t size)
102 {
103 	struct led_classdev *led_cdev = led_trigger_get_led(dev);
104 	unsigned long state;
105 	int ret;
106 
107 	ret = kstrtoul(buf, 0, &state);
108 	if (ret)
109 		return ret;
110 
111 	led_cdev->blink_delay_off = state;
112 
113 	return size;
114 }
115 
116 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
117 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
118 static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
119 static DEVICE_ATTR(shot, 0200, NULL, led_shot);
120 
121 static struct attribute *oneshot_trig_attrs[] = {
122 	&dev_attr_delay_on.attr,
123 	&dev_attr_delay_off.attr,
124 	&dev_attr_invert.attr,
125 	&dev_attr_shot.attr,
126 	NULL
127 };
128 ATTRIBUTE_GROUPS(oneshot_trig);
129 
pattern_init(struct led_classdev * led_cdev)130 static void pattern_init(struct led_classdev *led_cdev)
131 {
132 	u32 *pattern;
133 	unsigned int size = 0;
134 
135 	pattern = led_get_default_pattern(led_cdev, &size);
136 	if (!pattern)
137 		goto out_default;
138 
139 	if (size != 2) {
140 		dev_warn(led_cdev->dev,
141 			 "Expected 2 but got %u values for delays pattern\n",
142 			 size);
143 		goto out_default;
144 	}
145 
146 	led_cdev->blink_delay_on = pattern[0];
147 	led_cdev->blink_delay_off = pattern[1];
148 	kfree(pattern);
149 
150 	return;
151 
152 out_default:
153 	kfree(pattern);
154 	led_cdev->blink_delay_on = DEFAULT_DELAY;
155 	led_cdev->blink_delay_off = DEFAULT_DELAY;
156 }
157 
oneshot_trig_activate(struct led_classdev * led_cdev)158 static int oneshot_trig_activate(struct led_classdev *led_cdev)
159 {
160 	struct oneshot_trig_data *oneshot_data;
161 
162 	oneshot_data = kzalloc(sizeof(*oneshot_data), GFP_KERNEL);
163 	if (!oneshot_data)
164 		return -ENOMEM;
165 
166 	led_set_trigger_data(led_cdev, oneshot_data);
167 
168 	if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
169 		pattern_init(led_cdev);
170 		/*
171 		 * Mark as initialized even on pattern_init() error because
172 		 * any consecutive call to it would produce the same error.
173 		 */
174 		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
175 	}
176 
177 	return 0;
178 }
179 
oneshot_trig_deactivate(struct led_classdev * led_cdev)180 static void oneshot_trig_deactivate(struct led_classdev *led_cdev)
181 {
182 	struct oneshot_trig_data *oneshot_data = led_get_trigger_data(led_cdev);
183 
184 	kfree(oneshot_data);
185 
186 	/* Stop blinking */
187 	led_set_brightness(led_cdev, LED_OFF);
188 }
189 
190 static struct led_trigger oneshot_led_trigger = {
191 	.name     = "oneshot",
192 	.activate = oneshot_trig_activate,
193 	.deactivate = oneshot_trig_deactivate,
194 	.groups = oneshot_trig_groups,
195 };
196 module_led_trigger(oneshot_led_trigger);
197 
198 MODULE_AUTHOR("Fabio Baltieri <fabio.baltieri@gmail.com>");
199 MODULE_DESCRIPTION("One-shot LED trigger");
200 MODULE_LICENSE("GPL v2");
201