Merge tag 'xfs-4.17-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
[linux-2.6-microblaze.git] / drivers / leds / led-class.c
1 /*
2  * LED Class Core
3  *
4  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5  * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/ctype.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/leds.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/timer.h>
23 #include <uapi/linux/uleds.h>
24 #include "leds.h"
25
26 static struct class *leds_class;
27
28 static ssize_t brightness_show(struct device *dev,
29                 struct device_attribute *attr, char *buf)
30 {
31         struct led_classdev *led_cdev = dev_get_drvdata(dev);
32
33         /* no lock needed for this */
34         led_update_brightness(led_cdev);
35
36         return sprintf(buf, "%u\n", led_cdev->brightness);
37 }
38
39 static ssize_t brightness_store(struct device *dev,
40                 struct device_attribute *attr, const char *buf, size_t size)
41 {
42         struct led_classdev *led_cdev = dev_get_drvdata(dev);
43         unsigned long state;
44         ssize_t ret;
45
46         mutex_lock(&led_cdev->led_access);
47
48         if (led_sysfs_is_disabled(led_cdev)) {
49                 ret = -EBUSY;
50                 goto unlock;
51         }
52
53         ret = kstrtoul(buf, 10, &state);
54         if (ret)
55                 goto unlock;
56
57         if (state == LED_OFF)
58                 led_trigger_remove(led_cdev);
59         led_set_brightness(led_cdev, state);
60
61         ret = size;
62 unlock:
63         mutex_unlock(&led_cdev->led_access);
64         return ret;
65 }
66 static DEVICE_ATTR_RW(brightness);
67
68 static ssize_t max_brightness_show(struct device *dev,
69                 struct device_attribute *attr, char *buf)
70 {
71         struct led_classdev *led_cdev = dev_get_drvdata(dev);
72
73         return sprintf(buf, "%u\n", led_cdev->max_brightness);
74 }
75 static DEVICE_ATTR_RO(max_brightness);
76
77 #ifdef CONFIG_LEDS_TRIGGERS
78 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
79 static struct attribute *led_trigger_attrs[] = {
80         &dev_attr_trigger.attr,
81         NULL,
82 };
83 static const struct attribute_group led_trigger_group = {
84         .attrs = led_trigger_attrs,
85 };
86 #endif
87
88 static struct attribute *led_class_attrs[] = {
89         &dev_attr_brightness.attr,
90         &dev_attr_max_brightness.attr,
91         NULL,
92 };
93
94 static const struct attribute_group led_group = {
95         .attrs = led_class_attrs,
96 };
97
98 static const struct attribute_group *led_groups[] = {
99         &led_group,
100 #ifdef CONFIG_LEDS_TRIGGERS
101         &led_trigger_group,
102 #endif
103         NULL,
104 };
105
106 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
107 static ssize_t brightness_hw_changed_show(struct device *dev,
108                 struct device_attribute *attr, char *buf)
109 {
110         struct led_classdev *led_cdev = dev_get_drvdata(dev);
111
112         if (led_cdev->brightness_hw_changed == -1)
113                 return -ENODATA;
114
115         return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
116 }
117
118 static DEVICE_ATTR_RO(brightness_hw_changed);
119
120 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
121 {
122         struct device *dev = led_cdev->dev;
123         int ret;
124
125         ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
126         if (ret) {
127                 dev_err(dev, "Error creating brightness_hw_changed\n");
128                 return ret;
129         }
130
131         led_cdev->brightness_hw_changed_kn =
132                 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
133         if (!led_cdev->brightness_hw_changed_kn) {
134                 dev_err(dev, "Error getting brightness_hw_changed kn\n");
135                 device_remove_file(dev, &dev_attr_brightness_hw_changed);
136                 return -ENXIO;
137         }
138
139         return 0;
140 }
141
142 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
143 {
144         sysfs_put(led_cdev->brightness_hw_changed_kn);
145         device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
146 }
147
148 void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
149                                                enum led_brightness brightness)
150 {
151         if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
152                 return;
153
154         led_cdev->brightness_hw_changed = brightness;
155         sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
156 }
157 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
158 #else
159 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
160 {
161         return 0;
162 }
163 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
164 {
165 }
166 #endif
167
168 /**
169  * led_classdev_suspend - suspend an led_classdev.
170  * @led_cdev: the led_classdev to suspend.
171  */
172 void led_classdev_suspend(struct led_classdev *led_cdev)
173 {
174         led_cdev->flags |= LED_SUSPENDED;
175         led_set_brightness_nopm(led_cdev, 0);
176 }
177 EXPORT_SYMBOL_GPL(led_classdev_suspend);
178
179 /**
180  * led_classdev_resume - resume an led_classdev.
181  * @led_cdev: the led_classdev to resume.
182  */
183 void led_classdev_resume(struct led_classdev *led_cdev)
184 {
185         led_set_brightness_nopm(led_cdev, led_cdev->brightness);
186
187         if (led_cdev->flash_resume)
188                 led_cdev->flash_resume(led_cdev);
189
190         led_cdev->flags &= ~LED_SUSPENDED;
191 }
192 EXPORT_SYMBOL_GPL(led_classdev_resume);
193
194 #ifdef CONFIG_PM_SLEEP
195 static int led_suspend(struct device *dev)
196 {
197         struct led_classdev *led_cdev = dev_get_drvdata(dev);
198
199         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
200                 led_classdev_suspend(led_cdev);
201
202         return 0;
203 }
204
205 static int led_resume(struct device *dev)
206 {
207         struct led_classdev *led_cdev = dev_get_drvdata(dev);
208
209         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
210                 led_classdev_resume(led_cdev);
211
212         return 0;
213 }
214 #endif
215
216 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
217
218 static int match_name(struct device *dev, const void *data)
219 {
220         if (!dev_name(dev))
221                 return 0;
222         return !strcmp(dev_name(dev), (char *)data);
223 }
224
225 static int led_classdev_next_name(const char *init_name, char *name,
226                                   size_t len)
227 {
228         unsigned int i = 0;
229         int ret = 0;
230         struct device *dev;
231
232         strlcpy(name, init_name, len);
233
234         while ((ret < len) &&
235                (dev = class_find_device(leds_class, NULL, name, match_name))) {
236                 put_device(dev);
237                 ret = snprintf(name, len, "%s_%u", init_name, ++i);
238         }
239
240         if (ret >= len)
241                 return -ENOMEM;
242
243         return i;
244 }
245
246 /**
247  * of_led_classdev_register - register a new object of led_classdev class.
248  *
249  * @parent: parent of LED device
250  * @led_cdev: the led_classdev structure for this device.
251  * @np: DT node describing this LED
252  */
253 int of_led_classdev_register(struct device *parent, struct device_node *np,
254                             struct led_classdev *led_cdev)
255 {
256         char name[LED_MAX_NAME_SIZE];
257         int ret;
258
259         ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
260         if (ret < 0)
261                 return ret;
262
263         led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
264                                 led_cdev, led_cdev->groups, "%s", name);
265         if (IS_ERR(led_cdev->dev))
266                 return PTR_ERR(led_cdev->dev);
267         led_cdev->dev->of_node = np;
268
269         if (ret)
270                 dev_warn(parent, "Led %s renamed to %s due to name collision",
271                                 led_cdev->name, dev_name(led_cdev->dev));
272
273         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
274                 ret = led_add_brightness_hw_changed(led_cdev);
275                 if (ret) {
276                         device_unregister(led_cdev->dev);
277                         return ret;
278                 }
279         }
280
281         led_cdev->work_flags = 0;
282 #ifdef CONFIG_LEDS_TRIGGERS
283         init_rwsem(&led_cdev->trigger_lock);
284 #endif
285 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
286         led_cdev->brightness_hw_changed = -1;
287 #endif
288         mutex_init(&led_cdev->led_access);
289         /* add to the list of leds */
290         down_write(&leds_list_lock);
291         list_add_tail(&led_cdev->node, &leds_list);
292         up_write(&leds_list_lock);
293
294         if (!led_cdev->max_brightness)
295                 led_cdev->max_brightness = LED_FULL;
296
297         led_update_brightness(led_cdev);
298
299         led_init_core(led_cdev);
300
301 #ifdef CONFIG_LEDS_TRIGGERS
302         led_trigger_set_default(led_cdev);
303 #endif
304
305         dev_dbg(parent, "Registered led device: %s\n",
306                         led_cdev->name);
307
308         return 0;
309 }
310 EXPORT_SYMBOL_GPL(of_led_classdev_register);
311
312 /**
313  * led_classdev_unregister - unregisters a object of led_properties class.
314  * @led_cdev: the led device to unregister
315  *
316  * Unregisters a previously registered via led_classdev_register object.
317  */
318 void led_classdev_unregister(struct led_classdev *led_cdev)
319 {
320 #ifdef CONFIG_LEDS_TRIGGERS
321         down_write(&led_cdev->trigger_lock);
322         if (led_cdev->trigger)
323                 led_trigger_set(led_cdev, NULL);
324         up_write(&led_cdev->trigger_lock);
325 #endif
326
327         led_cdev->flags |= LED_UNREGISTERING;
328
329         /* Stop blinking */
330         led_stop_software_blink(led_cdev);
331
332         led_set_brightness(led_cdev, LED_OFF);
333
334         flush_work(&led_cdev->set_brightness_work);
335
336         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
337                 led_remove_brightness_hw_changed(led_cdev);
338
339         device_unregister(led_cdev->dev);
340
341         down_write(&leds_list_lock);
342         list_del(&led_cdev->node);
343         up_write(&leds_list_lock);
344
345         mutex_destroy(&led_cdev->led_access);
346 }
347 EXPORT_SYMBOL_GPL(led_classdev_unregister);
348
349 static void devm_led_classdev_release(struct device *dev, void *res)
350 {
351         led_classdev_unregister(*(struct led_classdev **)res);
352 }
353
354 /**
355  * devm_of_led_classdev_register - resource managed led_classdev_register()
356  *
357  * @parent: parent of LED device
358  * @led_cdev: the led_classdev structure for this device.
359  */
360 int devm_of_led_classdev_register(struct device *parent,
361                                   struct device_node *np,
362                                   struct led_classdev *led_cdev)
363 {
364         struct led_classdev **dr;
365         int rc;
366
367         dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
368         if (!dr)
369                 return -ENOMEM;
370
371         rc = of_led_classdev_register(parent, np, led_cdev);
372         if (rc) {
373                 devres_free(dr);
374                 return rc;
375         }
376
377         *dr = led_cdev;
378         devres_add(parent, dr);
379
380         return 0;
381 }
382 EXPORT_SYMBOL_GPL(devm_of_led_classdev_register);
383
384 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
385 {
386         struct led_cdev **p = res;
387
388         if (WARN_ON(!p || !*p))
389                 return 0;
390
391         return *p == data;
392 }
393
394 /**
395  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
396  * @parent: The device to unregister.
397  * @led_cdev: the led_classdev structure for this device.
398  */
399 void devm_led_classdev_unregister(struct device *dev,
400                                   struct led_classdev *led_cdev)
401 {
402         WARN_ON(devres_release(dev,
403                                devm_led_classdev_release,
404                                devm_led_classdev_match, led_cdev));
405 }
406 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
407
408 static int __init leds_init(void)
409 {
410         leds_class = class_create(THIS_MODULE, "leds");
411         if (IS_ERR(leds_class))
412                 return PTR_ERR(leds_class);
413         leds_class->pm = &leds_class_dev_pm_ops;
414         leds_class->dev_groups = led_groups;
415         return 0;
416 }
417
418 static void __exit leds_exit(void)
419 {
420         class_destroy(leds_class);
421 }
422
423 subsys_initcall(leds_init);
424 module_exit(leds_exit);
425
426 MODULE_AUTHOR("John Lenz, Richard Purdie");
427 MODULE_LICENSE("GPL");
428 MODULE_DESCRIPTION("LED Class Interface");