1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
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>
25 static struct class *leds_class
;
27 static ssize_t
brightness_show(struct device
*dev
,
28 struct device_attribute
*attr
, char *buf
)
30 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
32 /* no lock needed for this */
33 led_update_brightness(led_cdev
);
35 return sprintf(buf
, "%u\n", led_cdev
->brightness
);
38 static ssize_t
brightness_store(struct device
*dev
,
39 struct device_attribute
*attr
, const char *buf
, size_t size
)
41 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
45 mutex_lock(&led_cdev
->led_access
);
47 if (led_sysfs_is_disabled(led_cdev
)) {
52 ret
= kstrtoul(buf
, 10, &state
);
57 led_trigger_remove(led_cdev
);
58 led_set_brightness(led_cdev
, state
);
59 flush_work(&led_cdev
->set_brightness_work
);
63 mutex_unlock(&led_cdev
->led_access
);
66 static DEVICE_ATTR_RW(brightness
);
68 static ssize_t
max_brightness_show(struct device
*dev
,
69 struct device_attribute
*attr
, char *buf
)
71 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
73 return sprintf(buf
, "%u\n", led_cdev
->max_brightness
);
75 static DEVICE_ATTR_RO(max_brightness
);
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
[] = {
83 static const struct attribute_group led_trigger_group
= {
84 .bin_attrs
= led_trigger_bin_attrs
,
88 static struct attribute
*led_class_attrs
[] = {
89 &dev_attr_brightness
.attr
,
90 &dev_attr_max_brightness
.attr
,
94 static const struct attribute_group led_group
= {
95 .attrs
= led_class_attrs
,
98 static const struct attribute_group
*led_groups
[] = {
100 #ifdef CONFIG_LEDS_TRIGGERS
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
)
110 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
112 if (led_cdev
->brightness_hw_changed
== -1)
115 return sprintf(buf
, "%u\n", led_cdev
->brightness_hw_changed
);
118 static DEVICE_ATTR_RO(brightness_hw_changed
);
120 static int led_add_brightness_hw_changed(struct led_classdev
*led_cdev
)
122 struct device
*dev
= led_cdev
->dev
;
125 ret
= device_create_file(dev
, &dev_attr_brightness_hw_changed
);
127 dev_err(dev
, "Error creating brightness_hw_changed\n");
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
);
142 static void led_remove_brightness_hw_changed(struct led_classdev
*led_cdev
)
144 sysfs_put(led_cdev
->brightness_hw_changed_kn
);
145 device_remove_file(led_cdev
->dev
, &dev_attr_brightness_hw_changed
);
148 void led_classdev_notify_brightness_hw_changed(struct led_classdev
*led_cdev
, unsigned int brightness
)
150 if (WARN_ON(!led_cdev
->brightness_hw_changed_kn
))
153 led_cdev
->brightness_hw_changed
= brightness
;
154 sysfs_notify_dirent(led_cdev
->brightness_hw_changed_kn
);
156 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed
);
158 static int led_add_brightness_hw_changed(struct led_classdev
*led_cdev
)
162 static void led_remove_brightness_hw_changed(struct led_classdev
*led_cdev
)
168 * led_classdev_suspend - suspend an led_classdev.
169 * @led_cdev: the led_classdev to suspend.
171 void led_classdev_suspend(struct led_classdev
*led_cdev
)
173 led_cdev
->flags
|= LED_SUSPENDED
;
174 led_set_brightness_nopm(led_cdev
, 0);
175 flush_work(&led_cdev
->set_brightness_work
);
177 EXPORT_SYMBOL_GPL(led_classdev_suspend
);
180 * led_classdev_resume - resume an led_classdev.
181 * @led_cdev: the led_classdev to resume.
183 void led_classdev_resume(struct led_classdev
*led_cdev
)
185 led_set_brightness_nopm(led_cdev
, led_cdev
->brightness
);
187 if (led_cdev
->flash_resume
)
188 led_cdev
->flash_resume(led_cdev
);
190 led_cdev
->flags
&= ~LED_SUSPENDED
;
192 EXPORT_SYMBOL_GPL(led_classdev_resume
);
194 #ifdef CONFIG_PM_SLEEP
195 static int led_suspend(struct device
*dev
)
197 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
199 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
200 led_classdev_suspend(led_cdev
);
205 static int led_resume(struct device
*dev
)
207 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
209 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
210 led_classdev_resume(led_cdev
);
216 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops
, led_suspend
, led_resume
);
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
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.
226 struct led_classdev
*of_led_get(struct device_node
*np
, int index
)
228 struct device
*led_dev
;
229 struct led_classdev
*led_cdev
;
230 struct device_node
*led_node
;
232 led_node
= of_parse_phandle(np
, "leds", index
);
234 return ERR_PTR(-ENOENT
);
236 led_dev
= class_find_device_by_of_node(leds_class
, led_node
);
237 of_node_put(led_node
);
240 return ERR_PTR(-EPROBE_DEFER
);
242 led_cdev
= dev_get_drvdata(led_dev
);
244 if (!try_module_get(led_cdev
->dev
->parent
->driver
->owner
))
245 return ERR_PTR(-ENODEV
);
249 EXPORT_SYMBOL_GPL(of_led_get
);
252 * led_put() - release a LED device
253 * @led_cdev: LED device
255 void led_put(struct led_classdev
*led_cdev
)
257 module_put(led_cdev
->dev
->parent
->driver
->owner
);
259 EXPORT_SYMBOL_GPL(led_put
);
261 static void devm_led_release(struct device
*dev
, void *res
)
263 struct led_classdev
**p
= res
;
269 * devm_of_led_get - Resource-managed request of a LED device
271 * @index: index of the LED to obtain in the consumer
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
277 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
279 struct led_classdev
*__must_check
devm_of_led_get(struct device
*dev
,
282 struct led_classdev
*led
;
283 struct led_classdev
**dr
;
286 return ERR_PTR(-EINVAL
);
288 led
= of_led_get(dev
->of_node
, index
);
292 dr
= devres_alloc(devm_led_release
, sizeof(struct led_classdev
*),
296 return ERR_PTR(-ENOMEM
);
304 EXPORT_SYMBOL_GPL(devm_of_led_get
);
306 static int led_classdev_next_name(const char *init_name
, char *name
,
313 strlcpy(name
, init_name
, len
);
315 while ((ret
< len
) &&
316 (dev
= class_find_device_by_name(leds_class
, name
))) {
318 ret
= snprintf(name
, len
, "%s_%u", init_name
, ++i
);
328 * led_classdev_register_ext - register a new object of led_classdev class
331 * @parent: parent of LED device
332 * @led_cdev: the led_classdev structure for this device.
333 * @init_data: LED class device initialization data
335 int led_classdev_register_ext(struct device
*parent
,
336 struct led_classdev
*led_cdev
,
337 struct led_init_data
*init_data
)
339 char composed_name
[LED_MAX_NAME_SIZE
];
340 char final_name
[LED_MAX_NAME_SIZE
];
341 const char *proposed_name
= composed_name
;
345 if (init_data
->devname_mandatory
&& !init_data
->devicename
) {
346 dev_err(parent
, "Mandatory device name is missing");
349 ret
= led_compose_name(parent
, init_data
, composed_name
);
353 if (init_data
->fwnode
) {
354 fwnode_property_read_string(init_data
->fwnode
,
355 "linux,default-trigger",
356 &led_cdev
->default_trigger
);
358 if (fwnode_property_present(init_data
->fwnode
,
359 "retain-state-shutdown"))
360 led_cdev
->flags
|= LED_RETAIN_AT_SHUTDOWN
;
363 proposed_name
= led_cdev
->name
;
366 ret
= led_classdev_next_name(proposed_name
, final_name
, sizeof(final_name
));
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
);
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
);
384 dev_warn(parent
, "Led %s renamed to %s due to name collision",
385 proposed_name
, dev_name(led_cdev
->dev
));
387 if (led_cdev
->flags
& LED_BRIGHT_HW_CHANGED
) {
388 ret
= led_add_brightness_hw_changed(led_cdev
);
390 device_unregister(led_cdev
->dev
);
391 led_cdev
->dev
= NULL
;
392 mutex_unlock(&led_cdev
->led_access
);
397 led_cdev
->work_flags
= 0;
398 #ifdef CONFIG_LEDS_TRIGGERS
399 init_rwsem(&led_cdev
->trigger_lock
);
401 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
402 led_cdev
->brightness_hw_changed
= -1;
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
);
409 if (!led_cdev
->max_brightness
)
410 led_cdev
->max_brightness
= LED_FULL
;
412 led_update_brightness(led_cdev
);
414 led_init_core(led_cdev
);
416 #ifdef CONFIG_LEDS_TRIGGERS
417 led_trigger_set_default(led_cdev
);
420 mutex_unlock(&led_cdev
->led_access
);
422 dev_dbg(parent
, "Registered led device: %s\n",
427 EXPORT_SYMBOL_GPL(led_classdev_register_ext
);
430 * led_classdev_unregister - unregisters a object of led_properties class.
431 * @led_cdev: the led device to unregister
433 * Unregisters a previously registered via led_classdev_register object.
435 void led_classdev_unregister(struct led_classdev
*led_cdev
)
437 if (IS_ERR_OR_NULL(led_cdev
->dev
))
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
);
447 led_cdev
->flags
|= LED_UNREGISTERING
;
450 led_stop_software_blink(led_cdev
);
452 if (!(led_cdev
->flags
& LED_RETAIN_AT_SHUTDOWN
))
453 led_set_brightness(led_cdev
, LED_OFF
);
455 flush_work(&led_cdev
->set_brightness_work
);
457 if (led_cdev
->flags
& LED_BRIGHT_HW_CHANGED
)
458 led_remove_brightness_hw_changed(led_cdev
);
460 device_unregister(led_cdev
->dev
);
462 down_write(&leds_list_lock
);
463 list_del(&led_cdev
->node
);
464 up_write(&leds_list_lock
);
466 mutex_destroy(&led_cdev
->led_access
);
468 EXPORT_SYMBOL_GPL(led_classdev_unregister
);
470 static void devm_led_classdev_release(struct device
*dev
, void *res
)
472 led_classdev_unregister(*(struct led_classdev
**)res
);
476 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
478 * @parent: parent of LED device
479 * @led_cdev: the led_classdev structure for this device.
480 * @init_data: LED class device initialization data
482 int devm_led_classdev_register_ext(struct device
*parent
,
483 struct led_classdev
*led_cdev
,
484 struct led_init_data
*init_data
)
486 struct led_classdev
**dr
;
489 dr
= devres_alloc(devm_led_classdev_release
, sizeof(*dr
), GFP_KERNEL
);
493 rc
= led_classdev_register_ext(parent
, led_cdev
, init_data
);
500 devres_add(parent
, dr
);
504 EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext
);
506 static int devm_led_classdev_match(struct device
*dev
, void *res
, void *data
)
508 struct led_classdev
**p
= res
;
510 if (WARN_ON(!p
|| !*p
))
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.
521 void devm_led_classdev_unregister(struct device
*dev
,
522 struct led_classdev
*led_cdev
)
524 WARN_ON(devres_release(dev
,
525 devm_led_classdev_release
,
526 devm_led_classdev_match
, led_cdev
));
528 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister
);
530 static int __init
leds_init(void)
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
;
540 static void __exit
leds_exit(void)
542 class_destroy(leds_class
);
545 subsys_initcall(leds_init
);
546 module_exit(leds_exit
);
548 MODULE_AUTHOR("John Lenz, Richard Purdie");
549 MODULE_LICENSE("GPL");
550 MODULE_DESCRIPTION("LED Class Interface");