Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
[linux-2.6-microblaze.git] / drivers / leds / led-class.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * LED Class Core
4  *
5  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6  * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7  */
8
9 #include <linux/ctype.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/leds.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/property.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/timer.h>
21 #include <uapi/linux/uleds.h>
22 #include <linux/of.h>
23 #include "leds.h"
24
25 static struct class *leds_class;
26
27 static ssize_t brightness_show(struct device *dev,
28                 struct device_attribute *attr, char *buf)
29 {
30         struct led_classdev *led_cdev = dev_get_drvdata(dev);
31
32         /* no lock needed for this */
33         led_update_brightness(led_cdev);
34
35         return sprintf(buf, "%u\n", led_cdev->brightness);
36 }
37
38 static ssize_t brightness_store(struct device *dev,
39                 struct device_attribute *attr, const char *buf, size_t size)
40 {
41         struct led_classdev *led_cdev = dev_get_drvdata(dev);
42         unsigned long state;
43         ssize_t ret;
44
45         mutex_lock(&led_cdev->led_access);
46
47         if (led_sysfs_is_disabled(led_cdev)) {
48                 ret = -EBUSY;
49                 goto unlock;
50         }
51
52         ret = kstrtoul(buf, 10, &state);
53         if (ret)
54                 goto unlock;
55
56         if (state == LED_OFF)
57                 led_trigger_remove(led_cdev);
58         led_set_brightness(led_cdev, state);
59         flush_work(&led_cdev->set_brightness_work);
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 BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
79 static struct bin_attribute *led_trigger_bin_attrs[] = {
80         &bin_attr_trigger,
81         NULL,
82 };
83 static const struct attribute_group led_trigger_group = {
84         .bin_attrs = led_trigger_bin_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, unsigned int brightness)
149 {
150         if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
151                 return;
152
153         led_cdev->brightness_hw_changed = brightness;
154         sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
155 }
156 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
157 #else
158 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
159 {
160         return 0;
161 }
162 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
163 {
164 }
165 #endif
166
167 /**
168  * led_classdev_suspend - suspend an led_classdev.
169  * @led_cdev: the led_classdev to suspend.
170  */
171 void led_classdev_suspend(struct led_classdev *led_cdev)
172 {
173         led_cdev->flags |= LED_SUSPENDED;
174         led_set_brightness_nopm(led_cdev, 0);
175         flush_work(&led_cdev->set_brightness_work);
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 /**
219  * of_led_get() - request a LED device via the LED framework
220  * @np: device node to get the LED device from
221  * @index: the index of the LED
222  *
223  * Returns the LED device parsed from the phandle specified in the "leds"
224  * property of a device tree node or a negative error-code on failure.
225  */
226 struct led_classdev *of_led_get(struct device_node *np, int index)
227 {
228         struct device *led_dev;
229         struct led_classdev *led_cdev;
230         struct device_node *led_node;
231
232         led_node = of_parse_phandle(np, "leds", index);
233         if (!led_node)
234                 return ERR_PTR(-ENOENT);
235
236         led_dev = class_find_device_by_of_node(leds_class, led_node);
237         of_node_put(led_node);
238
239         if (!led_dev)
240                 return ERR_PTR(-EPROBE_DEFER);
241
242         led_cdev = dev_get_drvdata(led_dev);
243
244         if (!try_module_get(led_cdev->dev->parent->driver->owner))
245                 return ERR_PTR(-ENODEV);
246
247         return led_cdev;
248 }
249 EXPORT_SYMBOL_GPL(of_led_get);
250
251 /**
252  * led_put() - release a LED device
253  * @led_cdev: LED device
254  */
255 void led_put(struct led_classdev *led_cdev)
256 {
257         module_put(led_cdev->dev->parent->driver->owner);
258 }
259 EXPORT_SYMBOL_GPL(led_put);
260
261 static void devm_led_release(struct device *dev, void *res)
262 {
263         struct led_classdev **p = res;
264
265         led_put(*p);
266 }
267
268 /**
269  * devm_of_led_get - Resource-managed request of a LED device
270  * @dev:        LED consumer
271  * @index:      index of the LED to obtain in the consumer
272  *
273  * The device node of the device is parse to find the request LED device.
274  * The LED device returned from this function is automatically released
275  * on driver detach.
276  *
277  * @return a pointer to a LED device or ERR_PTR(errno) on failure.
278  */
279 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
280                                                   int index)
281 {
282         struct led_classdev *led;
283         struct led_classdev **dr;
284
285         if (!dev)
286                 return ERR_PTR(-EINVAL);
287
288         led = of_led_get(dev->of_node, index);
289         if (IS_ERR(led))
290                 return led;
291
292         dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
293                           GFP_KERNEL);
294         if (!dr) {
295                 led_put(led);
296                 return ERR_PTR(-ENOMEM);
297         }
298
299         *dr = led;
300         devres_add(dev, dr);
301
302         return led;
303 }
304 EXPORT_SYMBOL_GPL(devm_of_led_get);
305
306 static int led_classdev_next_name(const char *init_name, char *name,
307                                   size_t len)
308 {
309         unsigned int i = 0;
310         int ret = 0;
311         struct device *dev;
312
313         strlcpy(name, init_name, len);
314
315         while ((ret < len) &&
316                (dev = class_find_device_by_name(leds_class, name))) {
317                 put_device(dev);
318                 ret = snprintf(name, len, "%s_%u", init_name, ++i);
319         }
320
321         if (ret >= len)
322                 return -ENOMEM;
323
324         return i;
325 }
326
327 /**
328  * led_classdev_register_ext - register a new object of led_classdev class
329  *                             with init data.
330  *
331  * @parent: parent of LED device
332  * @led_cdev: the led_classdev structure for this device.
333  * @init_data: LED class device initialization data
334  */
335 int led_classdev_register_ext(struct device *parent,
336                               struct led_classdev *led_cdev,
337                               struct led_init_data *init_data)
338 {
339         char composed_name[LED_MAX_NAME_SIZE];
340         char final_name[LED_MAX_NAME_SIZE];
341         const char *proposed_name = composed_name;
342         int ret;
343
344         if (init_data) {
345                 if (init_data->devname_mandatory && !init_data->devicename) {
346                         dev_err(parent, "Mandatory device name is missing");
347                         return -EINVAL;
348                 }
349                 ret = led_compose_name(parent, init_data, composed_name);
350                 if (ret < 0)
351                         return ret;
352
353                 if (init_data->fwnode) {
354                         fwnode_property_read_string(init_data->fwnode,
355                                 "linux,default-trigger",
356                                 &led_cdev->default_trigger);
357
358                         if (fwnode_property_present(init_data->fwnode,
359                                                     "retain-state-shutdown"))
360                                 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
361                 }
362         } else {
363                 proposed_name = led_cdev->name;
364         }
365
366         ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
367         if (ret < 0)
368                 return ret;
369
370         mutex_init(&led_cdev->led_access);
371         mutex_lock(&led_cdev->led_access);
372         led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
373                                 led_cdev, led_cdev->groups, "%s", final_name);
374         if (IS_ERR(led_cdev->dev)) {
375                 mutex_unlock(&led_cdev->led_access);
376                 return PTR_ERR(led_cdev->dev);
377         }
378         if (init_data && init_data->fwnode) {
379                 led_cdev->dev->fwnode = init_data->fwnode;
380                 led_cdev->dev->of_node = to_of_node(init_data->fwnode);
381         }
382
383         if (ret)
384                 dev_warn(parent, "Led %s renamed to %s due to name collision",
385                                 proposed_name, dev_name(led_cdev->dev));
386
387         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
388                 ret = led_add_brightness_hw_changed(led_cdev);
389                 if (ret) {
390                         device_unregister(led_cdev->dev);
391                         led_cdev->dev = NULL;
392                         mutex_unlock(&led_cdev->led_access);
393                         return ret;
394                 }
395         }
396
397         led_cdev->work_flags = 0;
398 #ifdef CONFIG_LEDS_TRIGGERS
399         init_rwsem(&led_cdev->trigger_lock);
400 #endif
401 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
402         led_cdev->brightness_hw_changed = -1;
403 #endif
404         /* add to the list of leds */
405         down_write(&leds_list_lock);
406         list_add_tail(&led_cdev->node, &leds_list);
407         up_write(&leds_list_lock);
408
409         if (!led_cdev->max_brightness)
410                 led_cdev->max_brightness = LED_FULL;
411
412         led_update_brightness(led_cdev);
413
414         led_init_core(led_cdev);
415
416 #ifdef CONFIG_LEDS_TRIGGERS
417         led_trigger_set_default(led_cdev);
418 #endif
419
420         mutex_unlock(&led_cdev->led_access);
421
422         dev_dbg(parent, "Registered led device: %s\n",
423                         led_cdev->name);
424
425         return 0;
426 }
427 EXPORT_SYMBOL_GPL(led_classdev_register_ext);
428
429 /**
430  * led_classdev_unregister - unregisters a object of led_properties class.
431  * @led_cdev: the led device to unregister
432  *
433  * Unregisters a previously registered via led_classdev_register object.
434  */
435 void led_classdev_unregister(struct led_classdev *led_cdev)
436 {
437         if (IS_ERR_OR_NULL(led_cdev->dev))
438                 return;
439
440 #ifdef CONFIG_LEDS_TRIGGERS
441         down_write(&led_cdev->trigger_lock);
442         if (led_cdev->trigger)
443                 led_trigger_set(led_cdev, NULL);
444         up_write(&led_cdev->trigger_lock);
445 #endif
446
447         led_cdev->flags |= LED_UNREGISTERING;
448
449         /* Stop blinking */
450         led_stop_software_blink(led_cdev);
451
452         if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
453                 led_set_brightness(led_cdev, LED_OFF);
454
455         flush_work(&led_cdev->set_brightness_work);
456
457         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
458                 led_remove_brightness_hw_changed(led_cdev);
459
460         device_unregister(led_cdev->dev);
461
462         down_write(&leds_list_lock);
463         list_del(&led_cdev->node);
464         up_write(&leds_list_lock);
465
466         mutex_destroy(&led_cdev->led_access);
467 }
468 EXPORT_SYMBOL_GPL(led_classdev_unregister);
469
470 static void devm_led_classdev_release(struct device *dev, void *res)
471 {
472         led_classdev_unregister(*(struct led_classdev **)res);
473 }
474
475 /**
476  * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
477  *
478  * @parent: parent of LED device
479  * @led_cdev: the led_classdev structure for this device.
480  * @init_data: LED class device initialization data
481  */
482 int devm_led_classdev_register_ext(struct device *parent,
483                                    struct led_classdev *led_cdev,
484                                    struct led_init_data *init_data)
485 {
486         struct led_classdev **dr;
487         int rc;
488
489         dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
490         if (!dr)
491                 return -ENOMEM;
492
493         rc = led_classdev_register_ext(parent, led_cdev, init_data);
494         if (rc) {
495                 devres_free(dr);
496                 return rc;
497         }
498
499         *dr = led_cdev;
500         devres_add(parent, dr);
501
502         return 0;
503 }
504 EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
505
506 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
507 {
508         struct led_classdev **p = res;
509
510         if (WARN_ON(!p || !*p))
511                 return 0;
512
513         return *p == data;
514 }
515
516 /**
517  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
518  * @dev: The device to unregister.
519  * @led_cdev: the led_classdev structure for this device.
520  */
521 void devm_led_classdev_unregister(struct device *dev,
522                                   struct led_classdev *led_cdev)
523 {
524         WARN_ON(devres_release(dev,
525                                devm_led_classdev_release,
526                                devm_led_classdev_match, led_cdev));
527 }
528 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
529
530 static int __init leds_init(void)
531 {
532         leds_class = class_create(THIS_MODULE, "leds");
533         if (IS_ERR(leds_class))
534                 return PTR_ERR(leds_class);
535         leds_class->pm = &leds_class_dev_pm_ops;
536         leds_class->dev_groups = led_groups;
537         return 0;
538 }
539
540 static void __exit leds_exit(void)
541 {
542         class_destroy(leds_class);
543 }
544
545 subsys_initcall(leds_init);
546 module_exit(leds_exit);
547
548 MODULE_AUTHOR("John Lenz, Richard Purdie");
549 MODULE_LICENSE("GPL");
550 MODULE_DESCRIPTION("LED Class Interface");