OpenCloudOS-Kernel/include/linux/backlight.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Backlight Lowlevel Control Abstraction
*
* Copyright (C) 2003,2004 Hewlett-Packard Company
*
*/
#ifndef _LINUX_BACKLIGHT_H
#define _LINUX_BACKLIGHT_H
#include <linux/device.h>
#include <linux/fb.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
/* Notes on locking:
*
* backlight_device->ops_lock is an internal backlight lock protecting the
* ops pointer and no code outside the core should need to touch it.
*
* Access to update_status() is serialised by the update_lock mutex since
* most drivers seem to need this and historically get it wrong.
*
* Most drivers don't need locking on their get_brightness() method.
* If yours does, you need to implement it in the driver. You can use the
* update_lock mutex if appropriate.
*
* Any other use of the locks below is probably wrong.
*/
enum backlight_update_reason {
BACKLIGHT_UPDATE_HOTKEY,
BACKLIGHT_UPDATE_SYSFS,
};
enum backlight_type {
BACKLIGHT_RAW = 1,
BACKLIGHT_PLATFORM,
BACKLIGHT_FIRMWARE,
BACKLIGHT_TYPE_MAX,
};
enum backlight_notification {
BACKLIGHT_REGISTERED,
BACKLIGHT_UNREGISTERED,
};
enum backlight_scale {
BACKLIGHT_SCALE_UNKNOWN = 0,
BACKLIGHT_SCALE_LINEAR,
BACKLIGHT_SCALE_NON_LINEAR,
};
struct backlight_device;
struct fb_info;
struct backlight_ops {
unsigned int options;
#define BL_CORE_SUSPENDRESUME (1 << 0)
/* Notify the backlight driver some property has changed */
int (*update_status)(struct backlight_device *);
/* Return the current backlight brightness (accounting for power,
fb_blank etc.) */
int (*get_brightness)(struct backlight_device *);
/* Check if given framebuffer device is the one bound to this backlight;
return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
int (*check_fb)(struct backlight_device *, struct fb_info *);
};
/* This structure defines all the properties of a backlight */
struct backlight_properties {
/* Current User requested brightness (0 - max_brightness) */
int brightness;
/* Maximal value for brightness (read-only) */
int max_brightness;
/* Current FB Power mode (0: full on, 1..3: power saving
modes; 4: full off), see FB_BLANK_XXX */
int power;
/* FB Blanking active? (values as for power) */
/* Due to be removed, please use (state & BL_CORE_FBBLANK) */
int fb_blank;
/* Backlight type */
enum backlight_type type;
/* Flags used to signal drivers of state changes */
unsigned int state;
/* Type of the brightness scale (linear, non-linear, ...) */
enum backlight_scale scale;
#define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
#define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
};
struct backlight_device {
/* Backlight properties */
struct backlight_properties props;
/* Serialise access to update_status method */
struct mutex update_lock;
/* This protects the 'ops' field. If 'ops' is NULL, the driver that
registered this device has been unloaded, and if class_get_devdata()
points to something in the body of that driver, it is also invalid. */
struct mutex ops_lock;
const struct backlight_ops *ops;
/* The framebuffer notifier block */
struct notifier_block fb_notif;
/* list entry of all registered backlight devices */
struct list_head entry;
struct device dev;
/* Multiple framebuffers may share one backlight device */
bool fb_bl_on[FB_MAX];
int use_count;
};
static inline int backlight_update_status(struct backlight_device *bd)
{
int ret = -ENOENT;
mutex_lock(&bd->update_lock);
if (bd->ops && bd->ops->update_status)
ret = bd->ops->update_status(bd);
mutex_unlock(&bd->update_lock);
return ret;
}
/**
* backlight_enable - Enable backlight
* @bd: the backlight device to enable
*/
static inline int backlight_enable(struct backlight_device *bd)
{
if (!bd)
return 0;
bd->props.power = FB_BLANK_UNBLANK;
bd->props.fb_blank = FB_BLANK_UNBLANK;
bd->props.state &= ~BL_CORE_FBBLANK;
return backlight_update_status(bd);
}
/**
* backlight_disable - Disable backlight
* @bd: the backlight device to disable
*/
static inline int backlight_disable(struct backlight_device *bd)
{
if (!bd)
return 0;
bd->props.power = FB_BLANK_POWERDOWN;
bd->props.fb_blank = FB_BLANK_POWERDOWN;
bd->props.state |= BL_CORE_FBBLANK;
return backlight_update_status(bd);
}
/**
* backlight_put - Drop backlight reference
* @bd: the backlight device to put
*/
static inline void backlight_put(struct backlight_device *bd)
{
if (bd)
put_device(&bd->dev);
}
extern struct backlight_device *backlight_device_register(const char *name,
struct device *dev, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props);
extern struct backlight_device *devm_backlight_device_register(
struct device *dev, const char *name, struct device *parent,
void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props);
extern void backlight_device_unregister(struct backlight_device *bd);
extern void devm_backlight_device_unregister(struct device *dev,
struct backlight_device *bd);
extern void backlight_force_update(struct backlight_device *bd,
enum backlight_update_reason reason);
extern int backlight_register_notifier(struct notifier_block *nb);
extern int backlight_unregister_notifier(struct notifier_block *nb);
extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
extern int backlight_device_set_brightness(struct backlight_device *bd, unsigned long brightness);
#define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
static inline void * bl_get_data(struct backlight_device *bl_dev)
{
return dev_get_drvdata(&bl_dev->dev);
}
struct generic_bl_info {
const char *name;
int max_intensity;
int default_intensity;
int limit_mask;
void (*set_bl_intensity)(int intensity);
void (*kick_battery)(void);
};
#ifdef CONFIG_OF
struct backlight_device *of_find_backlight_by_node(struct device_node *node);
#else
static inline struct backlight_device *
of_find_backlight_by_node(struct device_node *node)
{
return NULL;
}
#endif
#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
struct backlight_device *of_find_backlight(struct device *dev);
struct backlight_device *devm_of_find_backlight(struct device *dev);
#else
static inline struct backlight_device *of_find_backlight(struct device *dev)
{
return NULL;
}
static inline struct backlight_device *
devm_of_find_backlight(struct device *dev)
{
return NULL;
}
#endif
#endif