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1// SPDX-License-Identifier: GPL-2.0
2//
3// LED Kernel Transient Trigger
4//
5// Transient trigger allows one shot timer activation. Please refer to
6// Documentation/leds/ledtrig-transient.rst for details
7// Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com>
8//
9// Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's
10// ledtrig-heartbeat.c
11// Design and use-case input from Jonas Bonn <jonas@southpole.se> and
12// Neil Brown <neilb@suse.de>
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/device.h>
18#include <linux/slab.h>
19#include <linux/timer.h>
20#include <linux/leds.h>
21#include "../leds.h"
22
23struct transient_trig_data {
24 int activate;
25 int state;
26 int restore_state;
27 unsigned long duration;
28 struct timer_list timer;
29 struct led_classdev *led_cdev;
30};
31
32static void transient_timer_function(struct timer_list *t)
33{
34 struct transient_trig_data *transient_data =
35 from_timer(transient_data, t, timer);
36 struct led_classdev *led_cdev = transient_data->led_cdev;
37
38 transient_data->activate = 0;
39 led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
40}
41
42static ssize_t transient_activate_show(struct device *dev,
43 struct device_attribute *attr, char *buf)
44{
45 struct transient_trig_data *transient_data =
46 led_trigger_get_drvdata(dev);
47
48 return sprintf(buf, "%d\n", transient_data->activate);
49}
50
51static ssize_t transient_activate_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 struct transient_trig_data *transient_data =
56 led_trigger_get_drvdata(dev);
57 unsigned long state;
58 ssize_t ret;
59
60 ret = kstrtoul(buf, 10, &state);
61 if (ret)
62 return ret;
63
64 if (state != 1 && state != 0)
65 return -EINVAL;
66
67 /* cancel the running timer */
68 if (state == 0 && transient_data->activate == 1) {
69 del_timer(&transient_data->timer);
70 transient_data->activate = state;
71 led_set_brightness_nosleep(led_cdev,
72 transient_data->restore_state);
73 return size;
74 }
75
76 /* start timer if there is no active timer */
77 if (state == 1 && transient_data->activate == 0 &&
78 transient_data->duration != 0) {
79 transient_data->activate = state;
80 led_set_brightness_nosleep(led_cdev, transient_data->state);
81 transient_data->restore_state =
82 (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
83 mod_timer(&transient_data->timer,
84 jiffies + msecs_to_jiffies(transient_data->duration));
85 }
86
87 /* state == 0 && transient_data->activate == 0
88 timer is not active - just return */
89 /* state == 1 && transient_data->activate == 1
90 timer is already active - just return */
91
92 return size;
93}
94
95static ssize_t transient_duration_show(struct device *dev,
96 struct device_attribute *attr, char *buf)
97{
98 struct transient_trig_data *transient_data = led_trigger_get_drvdata(dev);
99
100 return sprintf(buf, "%lu\n", transient_data->duration);
101}
102
103static ssize_t transient_duration_store(struct device *dev,
104 struct device_attribute *attr, const char *buf, size_t size)
105{
106 struct transient_trig_data *transient_data =
107 led_trigger_get_drvdata(dev);
108 unsigned long state;
109 ssize_t ret;
110
111 ret = kstrtoul(buf, 10, &state);
112 if (ret)
113 return ret;
114
115 transient_data->duration = state;
116 return size;
117}
118
119static ssize_t transient_state_show(struct device *dev,
120 struct device_attribute *attr, char *buf)
121{
122 struct transient_trig_data *transient_data =
123 led_trigger_get_drvdata(dev);
124 int state;
125
126 state = (transient_data->state == LED_FULL) ? 1 : 0;
127 return sprintf(buf, "%d\n", state);
128}
129
130static ssize_t transient_state_store(struct device *dev,
131 struct device_attribute *attr, const char *buf, size_t size)
132{
133 struct transient_trig_data *transient_data =
134 led_trigger_get_drvdata(dev);
135 unsigned long state;
136 ssize_t ret;
137
138 ret = kstrtoul(buf, 10, &state);
139 if (ret)
140 return ret;
141
142 if (state != 1 && state != 0)
143 return -EINVAL;
144
145 transient_data->state = (state == 1) ? LED_FULL : LED_OFF;
146 return size;
147}
148
149static DEVICE_ATTR(activate, 0644, transient_activate_show,
150 transient_activate_store);
151static DEVICE_ATTR(duration, 0644, transient_duration_show,
152 transient_duration_store);
153static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store);
154
155static struct attribute *transient_trig_attrs[] = {
156 &dev_attr_activate.attr,
157 &dev_attr_duration.attr,
158 &dev_attr_state.attr,
159 NULL
160};
161ATTRIBUTE_GROUPS(transient_trig);
162
163static int transient_trig_activate(struct led_classdev *led_cdev)
164{
165 struct transient_trig_data *tdata;
166
167 tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL);
168 if (!tdata)
169 return -ENOMEM;
170
171 led_set_trigger_data(led_cdev, tdata);
172 tdata->led_cdev = led_cdev;
173
174 timer_setup(&tdata->timer, transient_timer_function, 0);
175
176 return 0;
177}
178
179static void transient_trig_deactivate(struct led_classdev *led_cdev)
180{
181 struct transient_trig_data *transient_data = led_get_trigger_data(led_cdev);
182
183 timer_shutdown_sync(&transient_data->timer);
184 led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
185 kfree(transient_data);
186}
187
188static struct led_trigger transient_trigger = {
189 .name = "transient",
190 .activate = transient_trig_activate,
191 .deactivate = transient_trig_deactivate,
192 .groups = transient_trig_groups,
193};
194module_led_trigger(transient_trigger);
195
196MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>");
197MODULE_DESCRIPTION("Transient LED trigger");
198MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2//
3// LED Kernel Transient Trigger
4//
5// Transient trigger allows one shot timer activation. Please refer to
6// Documentation/leds/ledtrig-transient.rst for details
7// Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com>
8//
9// Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's
10// ledtrig-heartbeat.c
11// Design and use-case input from Jonas Bonn <jonas@southpole.se> and
12// Neil Brown <neilb@suse.de>
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/device.h>
18#include <linux/slab.h>
19#include <linux/timer.h>
20#include <linux/leds.h>
21#include "../leds.h"
22
23struct transient_trig_data {
24 int activate;
25 int state;
26 int restore_state;
27 unsigned long duration;
28 struct timer_list timer;
29 struct led_classdev *led_cdev;
30};
31
32static void transient_timer_function(struct timer_list *t)
33{
34 struct transient_trig_data *transient_data =
35 from_timer(transient_data, t, timer);
36 struct led_classdev *led_cdev = transient_data->led_cdev;
37
38 transient_data->activate = 0;
39 led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
40}
41
42static ssize_t transient_activate_show(struct device *dev,
43 struct device_attribute *attr, char *buf)
44{
45 struct transient_trig_data *transient_data =
46 led_trigger_get_drvdata(dev);
47
48 return sprintf(buf, "%d\n", transient_data->activate);
49}
50
51static ssize_t transient_activate_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 struct transient_trig_data *transient_data =
56 led_trigger_get_drvdata(dev);
57 unsigned long state;
58 ssize_t ret;
59
60 ret = kstrtoul(buf, 10, &state);
61 if (ret)
62 return ret;
63
64 if (state != 1 && state != 0)
65 return -EINVAL;
66
67 /* cancel the running timer */
68 if (state == 0 && transient_data->activate == 1) {
69 del_timer(&transient_data->timer);
70 transient_data->activate = state;
71 led_set_brightness_nosleep(led_cdev,
72 transient_data->restore_state);
73 return size;
74 }
75
76 /* start timer if there is no active timer */
77 if (state == 1 && transient_data->activate == 0 &&
78 transient_data->duration != 0) {
79 transient_data->activate = state;
80 led_set_brightness_nosleep(led_cdev, transient_data->state);
81 transient_data->restore_state =
82 (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
83 mod_timer(&transient_data->timer,
84 jiffies + msecs_to_jiffies(transient_data->duration));
85 }
86
87 /* state == 0 && transient_data->activate == 0
88 timer is not active - just return */
89 /* state == 1 && transient_data->activate == 1
90 timer is already active - just return */
91
92 return size;
93}
94
95static ssize_t transient_duration_show(struct device *dev,
96 struct device_attribute *attr, char *buf)
97{
98 struct transient_trig_data *transient_data = led_trigger_get_drvdata(dev);
99
100 return sprintf(buf, "%lu\n", transient_data->duration);
101}
102
103static ssize_t transient_duration_store(struct device *dev,
104 struct device_attribute *attr, const char *buf, size_t size)
105{
106 struct transient_trig_data *transient_data =
107 led_trigger_get_drvdata(dev);
108 unsigned long state;
109 ssize_t ret;
110
111 ret = kstrtoul(buf, 10, &state);
112 if (ret)
113 return ret;
114
115 transient_data->duration = state;
116 return size;
117}
118
119static ssize_t transient_state_show(struct device *dev,
120 struct device_attribute *attr, char *buf)
121{
122 struct transient_trig_data *transient_data =
123 led_trigger_get_drvdata(dev);
124 int state;
125
126 state = (transient_data->state == LED_FULL) ? 1 : 0;
127 return sprintf(buf, "%d\n", state);
128}
129
130static ssize_t transient_state_store(struct device *dev,
131 struct device_attribute *attr, const char *buf, size_t size)
132{
133 struct transient_trig_data *transient_data =
134 led_trigger_get_drvdata(dev);
135 unsigned long state;
136 ssize_t ret;
137
138 ret = kstrtoul(buf, 10, &state);
139 if (ret)
140 return ret;
141
142 if (state != 1 && state != 0)
143 return -EINVAL;
144
145 transient_data->state = (state == 1) ? LED_FULL : LED_OFF;
146 return size;
147}
148
149static DEVICE_ATTR(activate, 0644, transient_activate_show,
150 transient_activate_store);
151static DEVICE_ATTR(duration, 0644, transient_duration_show,
152 transient_duration_store);
153static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store);
154
155static struct attribute *transient_trig_attrs[] = {
156 &dev_attr_activate.attr,
157 &dev_attr_duration.attr,
158 &dev_attr_state.attr,
159 NULL
160};
161ATTRIBUTE_GROUPS(transient_trig);
162
163static int transient_trig_activate(struct led_classdev *led_cdev)
164{
165 struct transient_trig_data *tdata;
166
167 tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL);
168 if (!tdata)
169 return -ENOMEM;
170
171 led_set_trigger_data(led_cdev, tdata);
172 tdata->led_cdev = led_cdev;
173
174 timer_setup(&tdata->timer, transient_timer_function, 0);
175
176 return 0;
177}
178
179static void transient_trig_deactivate(struct led_classdev *led_cdev)
180{
181 struct transient_trig_data *transient_data = led_get_trigger_data(led_cdev);
182
183 timer_shutdown_sync(&transient_data->timer);
184 led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
185 kfree(transient_data);
186}
187
188static struct led_trigger transient_trigger = {
189 .name = "transient",
190 .activate = transient_trig_activate,
191 .deactivate = transient_trig_deactivate,
192 .groups = transient_trig_groups,
193};
194module_led_trigger(transient_trigger);
195
196MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>");
197MODULE_DESCRIPTION("Transient LED trigger");
198MODULE_LICENSE("GPL v2");