Lines Matching full:backlight

3  * Backlight Lowlevel Control Abstraction
14 #include <linux/backlight.h>
22 #include <asm/backlight.h>
28  * The backlight core supports implementing backlight drivers.
30  * A backlight driver registers a driver using
31  * devm_backlight_device_register(). The properties of the backlight
34  * the update_status() operation is called. The backlight driver shall
35  * implement this operation and use it to adjust backlight.
37  * Several sysfs attributes are provided by the backlight core::
43  * See Documentation/ABI/stable/sysfs-class-backlight for the full list.
45  * The backlight can be adjusted using the sysfs interface, and
46  * the backlight driver may also support adjusting backlight using
54  * When the backlight changes this is reported to user-space using
57  * a hot-key to adjust backlight, the driver must notify the backlight
60  * Display drives can control the backlight device's status using
62  * results in a change in the backlight state the functions call the
327 	.name = "backlight",
333  * backlight_force_update - tell the backlight subsystem that hardware state
335  * @bd: the backlight device to update
338  * Updates the internal state of the backlight in response to a hardware event,
339  * and generates an uevent to notify userspace. A backlight driver shall call
340  * backlight_force_update() when the backlight is changed using, for example,
392 			WARN(1, "%s: invalid backlight type", name);
422 /** backlight_device_get_by_type - find first backlight device of a type
423  * @type: the type of backlight device
425  * Look up the first backlight device of the specified type
429  * Pointer to backlight device if any was found. Otherwise NULL.
450  * backlight_device_get_by_name - Get backlight device by name
453  * This function looks up a backlight device by its name. It obtains a reference
454  * on the backlight device and it is the caller's responsibility to drop the
458  * A pointer to the backlight device if found, otherwise NULL.
497 	struct backlight_device *backlight = *(struct backlight_device **)res;
499 	backlight_device_unregister(backlight);
511  * devm_backlight_device_register - register a new backlight device
516  * @ops: the backlight operations structure
517  * @props: the backlight properties
519  * Creates and registers new backlight device. When a backlight device
525  * struct backlight on success, or an ERR_PTR on error
532 	struct backlight_device **ptr, *backlight;
539 	backlight = backlight_device_register(name, parent, devdata, ops,
541 	if (!IS_ERR(backlight)) {
542 		*ptr = backlight;
548 	return backlight;
553  * devm_backlight_device_unregister - unregister backlight device
555  * @bd: the backlight device to unregister
557  * Deallocates a backlight allocated with devm_backlight_device_register().
579  * of_find_backlight_by_node() - find backlight device by device-tree node
580  * @node: device-tree node of the backlight device
582  * Returns a pointer to the backlight device corresponding to the given DT
583  * node or NULL if no such backlight device exists or if the device hasn't
586  * This function obtains a reference on the backlight device and it is the
588  * the backlight device's .dev field.
610 		np = of_parse_phandle(dev->of_node, "backlight", 0);
630  * devm_of_find_backlight - find backlight for a device
633  * This function looks for a property named 'backlight' on the DT node
634  * connected to @dev and looks up the backlight device. The lookup is
635  * device managed so the reference to the backlight device is automatically
640  * A pointer to the backlight device if found.
641  * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
642  * device is found. NULL if there's no backlight property.
671 		pr_warn("Unable to create backlight class; errno = %d\n", ret);
690 MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");