History

Merge tag 'backlight-next-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones: "Core Framework: - Trivial: Code refactoring - New API backlight_is_blank() - New API backlight_get_brightness() - Additional/reworked documentation - Remove 'extern' labels from prototypes - Drop backlight_put() - Staticify of_find_backlight() Driver Removal: - Removal of unused OT200 driver - Removal of unused Generic Backlight driver Fix-ups - Bunch of W=1 warning fixes - Convert to GPIO descriptors; sky81452 - Move platform data handling into driver; sky81452 - Remove superfluous code; lms501kf03 - Many instances of using new APIs" * tag 'backlight-next-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: (34 commits) video: backlight: cr_bllcd: Remove unused variable 'intensity' backlight: backlight: Make of_find_backlight static backlight: backlight: Drop backlight_put() backlight: Use backlight_get_brightness() throughout backlight: jornada720_bl: Introduce backlight_is_blank() backlight: gpio_backlight: Simplify update_status() backlight: cr_bllcd: Introduce gpio-backlight semantics backlight: as3711_bl: Simplify update_status backlight: backlight: Introduce backlight_get_brightness() doc-rst: Wire-up Backlight kernel-doc documentation backlight: backlight: Add overview and update existing doc backlight: backlight: Drop extern from prototypes backlight: generic_bl: Remove this driver as it is unused backlight: backlight: Document enums in backlight.h backlight: backlight: Document inline functions in backlight.h backlight: backlight: Improve backlight_device documentation backlight: backlight: Improve backlight_properties documentation backlight: backlight: Improve backlight_ops documentation backlight: backlight: Add backlight_is_blank() backlight: backlight: Refactor fb_notifier_callback() ...

Linus Torvalds committed 6 years ago

Commit 96f970f2 parents c636eef 7eb99a339 files · +538 −717Browse files

Showing the changes to include/linux (3 of 39 files). Show all

Unified · Split

3 files
  1. include/linux/backlight.h +325 −74
  2. include/linux/mfd/sky81452.h +0 −2
  3. include/linux/platform_data/sky81452-backlight.h +0 −35
include/linux/backlight.h+325−74
@@ -14,113 +14,336 @@ · 13 unmodified lines
1414 #include <linux/mutex.h>
1515 #include <linux/notifier.h>
1616
17−/* Notes on locking:
18− *
19− * backlight_device->ops_lock is an internal backlight lock protecting the
20− * ops pointer and no code outside the core should need to touch it.
21− *
22− * Access to update_status() is serialised by the update_lock mutex since
23− * most drivers seem to need this and historically get it wrong.
24− *
25− * Most drivers don't need locking on their get_brightness() method.
26− * If yours does, you need to implement it in the driver. You can use the
27− * update_lock mutex if appropriate.
17+/**
18+ * enum backlight_update_reason - what method was used to update backlight
2819 *
29− * Any other use of the locks below is probably wrong.
20+ * A driver indicates the method (reason) used for updating the backlight
21+ * when calling backlight_force_update().
3022 */
31−
3223 enum backlight_update_reason {
24+ /**
25+ * @BACKLIGHT_UPDATE_HOTKEY: The backlight was updated using a hot-key.
26+ */
3327 BACKLIGHT_UPDATE_HOTKEY,
28+
29+ /**
30+ * @BACKLIGHT_UPDATE_SYSFS: The backlight was updated using sysfs.
31+ */
3432 BACKLIGHT_UPDATE_SYSFS,
3533 };
3634
35+/**
36+ * enum backlight_type - the type of backlight control
37+ *
38+ * The type of interface used to control the backlight.
39+ */
3740 enum backlight_type {
41+ /**
42+ * @BACKLIGHT_RAW:
43+ *
44+ * The backlight is controlled using hardware registers.
45+ */
3846 BACKLIGHT_RAW = 1,
47+
48+ /**
49+ * @BACKLIGHT_PLATFORM:
50+ *
51+ * The backlight is controlled using a platform-specific interface.
52+ */
3953 BACKLIGHT_PLATFORM,
54+
55+ /**
56+ * @BACKLIGHT_FIRMWARE:
57+ *
58+ * The backlight is controlled using a standard firmware interface.
59+ */
4060 BACKLIGHT_FIRMWARE,
61+
62+ /**
63+ * @BACKLIGHT_TYPE_MAX: Number of entries.
64+ */
4165 BACKLIGHT_TYPE_MAX,
4266 };
4367
68+/**
69+ * enum backlight_notification - the type of notification
70+ *
71+ * The notifications that is used for notification sent to the receiver
72+ * that registered notifications using backlight_register_notifier().
73+ */
4474 enum backlight_notification {
75+ /**
76+ * @BACKLIGHT_REGISTERED: The backlight device is registered.
77+ */
4578 BACKLIGHT_REGISTERED,
79+
80+ /**
81+ * @BACKLIGHT_UNREGISTERED: The backlight revice is unregistered.
82+ */
4683 BACKLIGHT_UNREGISTERED,
4784 };
4885
86+/** enum backlight_scale - the type of scale used for brightness values
87+ *
88+ * The type of scale used for brightness values.
89+ */
4990 enum backlight_scale {
91+ /**
92+ * @BACKLIGHT_SCALE_UNKNOWN: The scale is unknown.
93+ */
5094 BACKLIGHT_SCALE_UNKNOWN = 0,
95+
96+ /**
97+ * @BACKLIGHT_SCALE_LINEAR: The scale is linear.
98+ *
99+ * The linear scale will increase brightness the same for each step.
100+ */
51101 BACKLIGHT_SCALE_LINEAR,
102+
103+ /**
104+ * @BACKLIGHT_SCALE_NON_LINEAR: The scale is not linear.
105+ *
106+ * This is often used when the brightness values tries to adjust to
107+ * the relative perception of the eye demanding a non-linear scale.
108+ */
52109 BACKLIGHT_SCALE_NON_LINEAR,
53110 };
54111
55112 struct backlight_device;
56113 struct fb_info;
57114
115+/**
116+ * struct backlight_ops - backlight operations
117+ *
118+ * The backlight operations are specified when the backlight device is registered.
119+ */
58120 struct backlight_ops {
121+ /**
122+ * @options: Configure how operations are called from the core.
123+ *
124+ * The options parameter is used to adjust the behaviour of the core.
125+ * Set BL_CORE_SUSPENDRESUME to get the update_status() operation called
126+ * upon suspend and resume.
127+ */
59128 unsigned int options;
60129
61130 #define BL_CORE_SUSPENDRESUME (1 << 0)
62131
63− /* Notify the backlight driver some property has changed */
132+ /**
133+ * @update_status: Operation called when properties have changed.
134+ *
135+ * Notify the backlight driver some property has changed.
136+ * The update_status operation is protected by the update_lock.
137+ *
138+ * The backlight driver is expected to use backlight_is_blank()
139+ * to check if the display is blanked and set brightness accordingly.
140+ * update_status() is called when any of the properties has changed.
141+ *
142+ * RETURNS:
143+ *
144+ * 0 on success, negative error code if any failure occurred.
145+ */
64146 int (*update_status)(struct backlight_device *);
65− /* Return the current backlight brightness (accounting for power,
66− fb_blank etc.) */
147+
148+ /**
149+ * @get_brightness: Return the current backlight brightness.
150+ *
151+ * The driver may implement this as a readback from the HW.
152+ * This operation is optional and if not present then the current
153+ * brightness property value is used.
154+ *
155+ * RETURNS:
156+ *
157+ * A brightness value which is 0 or a positive number.
158+ * On failure a negative error code is returned.
159+ */
67160 int (*get_brightness)(struct backlight_device *);
68− /* Check if given framebuffer device is the one bound to this backlight;
69− return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
70− int (*check_fb)(struct backlight_device *, struct fb_info *);
161+
162+ /**
163+ * @check_fb: Check the framebuffer device.
164+ *
165+ * Check if given framebuffer device is the one bound to this backlight.
166+ * This operation is optional and if not implemented it is assumed that the
167+ * fbdev is always the one bound to the backlight.
168+ *
169+ * RETURNS:
170+ *
171+ * If info is NULL or the info matches the fbdev bound to the backlight return true.
172+ * If info does not match the fbdev bound to the backlight return false.
173+ */
174+ int (*check_fb)(struct backlight_device *bd, struct fb_info *info);
71175 };
72176
73−/* This structure defines all the properties of a backlight */
177+/**
178+ * struct backlight_properties - backlight properties
179+ *
180+ * This structure defines all the properties of a backlight.
181+ */
74182 struct backlight_properties {
75− /* Current User requested brightness (0 - max_brightness) */
183+ /**
184+ * @brightness: The current brightness requested by the user.
185+ *
186+ * The backlight core makes sure the range is (0 to max_brightness)
187+ * when the brightness is set via the sysfs attribute:
188+ * /sys/class/backlight/<backlight>/brightness.
189+ *
190+ * This value can be set in the backlight_properties passed
191+ * to devm_backlight_device_register() to set a default brightness
192+ * value.
193+ */
76194 int brightness;
77− /* Maximal value for brightness (read-only) */
195+
196+ /**
197+ * @max_brightness: The maximum brightness value.
198+ *
199+ * This value must be set in the backlight_properties passed to
200+ * devm_backlight_device_register() and shall not be modified by the
201+ * driver after registration.
202+ */
78203 int max_brightness;
79− /* Current FB Power mode (0: full on, 1..3: power saving
80− modes; 4: full off), see FB_BLANK_XXX */
204+
205+ /**
206+ * @power: The current power mode.
207+ *
208+ * User space can configure the power mode using the sysfs
209+ * attribute: /sys/class/backlight/<backlight>/bl_power
210+ * When the power property is updated update_status() is called.
211+ *
212+ * The possible values are: (0: full on, 1 to 3: power saving
213+ * modes; 4: full off), see FB_BLANK_XXX.
214+ *
215+ * When the backlight device is enabled @power is set
216+ * to FB_BLANK_UNBLANK. When the backlight device is disabled
217+ * @power is set to FB_BLANK_POWERDOWN.
218+ */
81219 int power;
82− /* FB Blanking active? (values as for power) */
83− /* Due to be removed, please use (state & BL_CORE_FBBLANK) */
220+
221+ /**
222+ * @fb_blank: The power state from the FBIOBLANK ioctl.
223+ *
224+ * When the FBIOBLANK ioctl is called @fb_blank is set to the
225+ * blank parameter and the update_status() operation is called.
226+ *
227+ * When the backlight device is enabled @fb_blank is set
228+ * to FB_BLANK_UNBLANK. When the backlight device is disabled
229+ * @fb_blank is set to FB_BLANK_POWERDOWN.
230+ *
231+ * Backlight drivers should avoid using this property. It has been
232+ * replaced by state & BL_CORE_FBLANK (although most drivers should
233+ * use backlight_is_blank() as the preferred means to get the blank
234+ * state).
235+ *
236+ * fb_blank is deprecated and will be removed.
237+ */
84238 int fb_blank;
85− /* Backlight type */
239+
240+ /**
241+ * @type: The type of backlight supported.
242+ *
243+ * The backlight type allows userspace to make appropriate
244+ * policy decisions based on the backlight type.
245+ *
246+ * This value must be set in the backlight_properties
247+ * passed to devm_backlight_device_register().
248+ */
86249 enum backlight_type type;
87− /* Flags used to signal drivers of state changes */
250+
251+ /**
252+ * @state: The state of the backlight core.
253+ *
254+ * The state is a bitmask. BL_CORE_FBBLANK is set when the display
255+ * is expected to be blank. BL_CORE_SUSPENDED is set when the
256+ * driver is suspended.
257+ *
258+ * backlight drivers are expected to use backlight_is_blank()
259+ * in their update_status() operation rather than reading the
260+ * state property.
261+ *
262+ * The state is maintained by the core and drivers may not modify it.
263+ */
88264 unsigned int state;
89− /* Type of the brightness scale (linear, non-linear, ...) */
90− enum backlight_scale scale;
91265
92266 #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
93267 #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
94268
269+ /**
270+ * @scale: The type of the brightness scale.
271+ */
272+ enum backlight_scale scale;
95273 };
96274
275+/**
276+ * struct backlight_device - backlight device data
277+ *
278+ * This structure holds all data required by a backlight device.
279+ */
97280 struct backlight_device {
98− /* Backlight properties */
281+ /**
282+ * @props: Backlight properties
283+ */
99284 struct backlight_properties props;
100285
101− /* Serialise access to update_status method */
286+ /**
287+ * @update_lock: The lock used when calling the update_status() operation.
288+ *
289+ * update_lock is an internal backlight lock that serialise access
290+ * to the update_status() operation. The backlight core holds the update_lock
291+ * when calling the update_status() operation. The update_lock shall not
292+ * be used by backlight drivers.
293+ */
102294 struct mutex update_lock;
103295
104− /* This protects the 'ops' field. If 'ops' is NULL, the driver that
105− registered this device has been unloaded, and if class_get_devdata()
106− points to something in the body of that driver, it is also invalid. */
296+ /**
297+ * @ops_lock: The lock used around everything related to backlight_ops.
298+ *
299+ * ops_lock is an internal backlight lock that protects the ops pointer
300+ * and is used around all accesses to ops and when the operations are
301+ * invoked. The ops_lock shall not be used by backlight drivers.
302+ */
107303 struct mutex ops_lock;
304+
305+ /**
306+ * @ops: Pointer to the backlight operations.
307+ *
308+ * If ops is NULL, the driver that registered this device has been unloaded,
309+ * and if class_get_devdata() points to something in the body of that driver,
310+ * it is also invalid.
311+ */
108312 const struct backlight_ops *ops;
109313
110− /* The framebuffer notifier block */
314+ /**
315+ * @fb_notif: The framebuffer notifier block
316+ */
111317 struct notifier_block fb_notif;
112318
113− /* list entry of all registered backlight devices */
319+ /**
320+ * @entry: List entry of all registered backlight devices
321+ */
114322 struct list_head entry;
115323
324+ /**
325+ * @dev: Parent device.
326+ */
116327 struct device dev;
117328
118− /* Multiple framebuffers may share one backlight device */
329+ /**
330+ * @fb_bl_on: The state of individual fbdev's.
331+ *
332+ * Multiple fbdev's may share one backlight device. The fb_bl_on
333+ * records the state of the individual fbdev.
334+ */
119335 bool fb_bl_on[FB_MAX];
120336
337+ /**
338+ * @use_count: The number of uses of fb_bl_on.
339+ */
121340 int use_count;
122341 };
123342
343+/**
344+ * backlight_update_status - force an update of the backlight device status
345+ * @bd: the backlight device
346+ */
124347 static inline int backlight_update_status(struct backlight_device *bd)
125348 {
126349 int ret = -ENOENT;
@@ -166,49 +389,83 @@ static inline int backlight_disable(struct backlight_device *bd) · 39 unmodified lines
166389 }
167390
168391 /**
169− * backlight_put - Drop backlight reference
170− * @bd: the backlight device to put
392+ * backlight_is_blank - Return true if display is expected to be blank
393+ * @bd: the backlight device
394+ *
395+ * Display is expected to be blank if any of these is true::
396+ *
397+ * 1) if power in not UNBLANK
398+ * 2) if fb_blank is not UNBLANK
399+ * 3) if state indicate BLANK or SUSPENDED
400+ *
401+ * Returns true if display is expected to be blank, false otherwise.
171402 */
172−static inline void backlight_put(struct backlight_device *bd)
403+static inline bool backlight_is_blank(const struct backlight_device *bd)
173404 {
174− if (bd)
175− put_device(&bd->dev);
405+ return bd->props.power != FB_BLANK_UNBLANK ||
406+ bd->props.fb_blank != FB_BLANK_UNBLANK ||
407+ bd->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK);
176408 }
177409
178−extern struct backlight_device *backlight_device_register(const char *name,
179− struct device *dev, void *devdata, const struct backlight_ops *ops,
180− const struct backlight_properties *props);
181−extern struct backlight_device *devm_backlight_device_register(
182− struct device *dev, const char *name, struct device *parent,
183− void *devdata, const struct backlight_ops *ops,
184− const struct backlight_properties *props);
185−extern void backlight_device_unregister(struct backlight_device *bd);
186−extern void devm_backlight_device_unregister(struct device *dev,
187− struct backlight_device *bd);
188−extern void backlight_force_update(struct backlight_device *bd,
189− enum backlight_update_reason reason);
190−extern int backlight_register_notifier(struct notifier_block *nb);
191−extern int backlight_unregister_notifier(struct notifier_block *nb);
192−extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
410+/**
411+ * backlight_get_brightness - Returns the current brightness value
412+ * @bd: the backlight device
413+ *
414+ * Returns the current brightness value, taking in consideration the current
415+ * state. If backlight_is_blank() returns true then return 0 as brightness
416+ * otherwise return the current brightness property value.
417+ *
418+ * Backlight drivers are expected to use this function in their update_status()
419+ * operation to get the brightness value.
420+ */
421+static inline int backlight_get_brightness(const struct backlight_device *bd)
422+{
423+ if (backlight_is_blank(bd))
424+ return 0;
425+ else
426+ return bd->props.brightness;
427+}
428+
429+struct backlight_device *
430+backlight_device_register(const char *name, struct device *dev, void *devdata,
431+ const struct backlight_ops *ops,
432+ const struct backlight_properties *props);
433+struct backlight_device *
434+devm_backlight_device_register(struct device *dev, const char *name,
435+ struct device *parent, void *devdata,
436+ const struct backlight_ops *ops,
437+ const struct backlight_properties *props);
438+void backlight_device_unregister(struct backlight_device *bd);
439+void devm_backlight_device_unregister(struct device *dev,
440+ struct backlight_device *bd);
441+void backlight_force_update(struct backlight_device *bd,
442+ enum backlight_update_reason reason);
443+int backlight_register_notifier(struct notifier_block *nb);
444+int backlight_unregister_notifier(struct notifier_block *nb);
193445 struct backlight_device *backlight_device_get_by_name(const char *name);
194−extern int backlight_device_set_brightness(struct backlight_device *bd, unsigned long brightness);
446+struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
447+int backlight_device_set_brightness(struct backlight_device *bd,
448+ unsigned long brightness);
195449
196450 #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
197451
452+/**
453+ * bl_get_data - access devdata
454+ * @bl_dev: pointer to backlight device
455+ *
456+ * When a backlight device is registered the driver has the possibility
457+ * to supply a void * devdata. bl_get_data() return a pointer to the
458+ * devdata.
459+ *
460+ * RETURNS:
461+ *
462+ * pointer to devdata stored while registering the backlight device.
463+ */
198464 static inline void * bl_get_data(struct backlight_device *bl_dev)
199465 {
200466 return dev_get_drvdata(&bl_dev->dev);
201467 }
202468
203−struct generic_bl_info {
204− const char *name;
205− int max_intensity;
206− int default_intensity;
207− int limit_mask;
208− void (*set_bl_intensity)(int intensity);
209− void (*kick_battery)(void);
210−};
211−
212469 #ifdef CONFIG_OF
213470 struct backlight_device *of_find_backlight_by_node(struct device_node *node);
214471 #else
@@ -220,14 +477,8 @@ of_find_backlight_by_node(struct device_node *node) · 5 unmodified lines
220477 #endif
221478
222479 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
223−struct backlight_device *of_find_backlight(struct device *dev);
224480 struct backlight_device *devm_of_find_backlight(struct device *dev);
225481 #else
226−static inline struct backlight_device *of_find_backlight(struct device *dev)
227−{
228− return NULL;
229−}
230−
231482 static inline struct backlight_device *
232483 devm_of_find_backlight(struct device *dev)
233484 {
include/linux/mfd/sky81452.h+0−2
@@ -9,11 +9,9 @@ · 8 unmodified lines
99 #ifndef _SKY81452_H
1010 #define _SKY81452_H
1111
12−#include <linux/platform_data/sky81452-backlight.h>
1312 #include <linux/regulator/machine.h>
1413
1514 struct sky81452_platform_data {
16− struct sky81452_bl_platform_data *bl_pdata;
1715 struct regulator_init_data *regulator_init_data;
1816 };
1917
include/linux/platform_data/sky81452-backlight.h+0−35
@@ -1,35 +0,0 @@
1−/* SPDX-License-Identifier: GPL-2.0-only */
2−/*
3− * sky81452.h SKY81452 backlight driver
4− *
5− * Copyright 2014 Skyworks Solutions Inc.
6− * Author : Gyungoh Yoo <jack.yoo@skyworksinc.com>
7− */
8−
9−#ifndef _SKY81452_BACKLIGHT_H
10−#define _SKY81452_BACKLIGHT_H
11−
12−/**
13− * struct sky81452_platform_data
14− * @name: backlight driver name.
15− If it is not defined, default name is lcd-backlight.
16− * @gpio_enable:GPIO number which control EN pin
17− * @enable: Enable mask for current sink channel 1, 2, 3, 4, 5 and 6.
18− * @ignore_pwm: true if DPWMI should be ignored.
19− * @dpwm_mode: true is DPWM dimming mode, otherwise Analog dimming mode.
20− * @phase_shift:true is phase shift mode.
21− * @short_detecion_threshold: It should be one of 4, 5, 6 and 7V.
22− * @boost_current_limit: It should be one of 2300, 2750mA.
23− */
24−struct sky81452_bl_platform_data {
25− const char *name;
26− int gpio_enable;
27− unsigned int enable;
28− bool ignore_pwm;
29− bool dpwm_mode;
30− bool phase_shift;
31− unsigned int short_detection_threshold;
32− unsigned int boost_current_limit;
33−};
34−
35−#endif