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
21struct oneshot_trig_data {
22	unsigned int invert;
23};
24
25static 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}
38static 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
46static 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
68static 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
76static 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
92static 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
100static 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
116static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
117static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
118static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
119static DEVICE_ATTR(shot, 0200, NULL, led_shot);
120
121static 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};
128ATTRIBUTE_GROUPS(oneshot_trig);
129
130static 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
152out_default:
153	kfree(pattern);
154	led_cdev->blink_delay_on = DEFAULT_DELAY;
155	led_cdev->blink_delay_off = DEFAULT_DELAY;
156}
157
158static 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
180static 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
190static 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};
196module_led_trigger(oneshot_led_trigger);
197
198MODULE_AUTHOR("Fabio Baltieri <fabio.baltieri@gmail.com>");
199MODULE_DESCRIPTION("One-shot LED trigger");
200MODULE_LICENSE("GPL v2");
201