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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - include/linux/lcd.h
1 /* SPDX-License-Identifier: GPL-2.0 */
3 * LCD Lowlevel Control Abstraction
5 * Copyright (C) 2003,2004 Hewlett-Packard Company
12 #include <linux/device.h>
13 #include <linux/mutex.h>
14 #include <linux/notifier.h>
19 * lcd_device->ops_lock is an internal backlight lock protecting the ops
20 * field and no code outside the core should need to touch it.
22 * Access to set_power() is serialised by the update_lock mutex since
23 * most drivers seem to need this and historically get it wrong.
25 * Most drivers don't need locking on their get_power() method.
26 * If yours does, you need to implement it in the driver. You can use the
27 * update_lock mutex if appropriate.
29 * Any other use of the locks below is probably wrong.
35 struct lcd_properties
{
36 /* The maximum value for contrast (read-only) */
41 /* Get the LCD panel power status (0: full on, 1..3: controller
42 power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
43 int (*get_power
)(struct lcd_device
*);
45 * Enable or disable power to the LCD(0: on; 4: off, see FB_BLANK_XXX)
46 * and this callback would be called proir to fb driver's callback.
48 * P.S. note that if early_set_power is not NULL then early fb notifier
49 * would be registered.
51 int (*early_set_power
)(struct lcd_device
*, int power
);
52 /* revert the effects of the early blank event. */
53 int (*r_early_set_power
)(struct lcd_device
*, int power
);
54 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
55 int (*set_power
)(struct lcd_device
*, int power
);
56 /* Get the current contrast setting (0-max_contrast) */
57 int (*get_contrast
)(struct lcd_device
*);
58 /* Set LCD panel contrast */
59 int (*set_contrast
)(struct lcd_device
*, int contrast
);
60 /* Set LCD panel mode (resolutions ...) */
61 int (*set_mode
)(struct lcd_device
*, struct fb_videomode
*);
62 /* Check if given framebuffer device is the one LCD is bound to;
63 return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
64 int (*check_fb
)(struct lcd_device
*, struct fb_info
*);
68 struct lcd_properties props
;
69 /* This protects the 'ops' field. If 'ops' is NULL, the driver that
70 registered this device has been unloaded, and if class_get_devdata()
71 points to something in the body of that driver, it is also invalid. */
72 struct mutex ops_lock
;
73 /* If this is NULL, the backing module is unloaded */
75 /* Serialise access to set_power method */
76 struct mutex update_lock
;
77 /* The framebuffer notifier block */
78 struct notifier_block fb_notif
;
83 struct lcd_platform_data
{
84 /* reset lcd panel device. */
85 int (*reset
)(struct lcd_device
*ld
);
86 /* on or off to lcd panel. if 'enable' is 0 then
87 lcd power off and 1, lcd power on. */
88 int (*power_on
)(struct lcd_device
*ld
, int enable
);
90 /* it indicates whether lcd panel was enabled
91 from bootloader or not. */
93 /* it means delay for stable time when it becomes low to high
94 or high to low that is dependent on whether reset gpio is
95 low active or high active. */
96 unsigned int reset_delay
;
97 /* stable time needing to become lcd power on. */
98 unsigned int power_on_delay
;
99 /* stable time needing to become lcd power off. */
100 unsigned int power_off_delay
;
102 /* it could be used for any purpose. */
106 static inline void lcd_set_power(struct lcd_device
*ld
, int power
)
108 mutex_lock(&ld
->update_lock
);
109 if (ld
->ops
&& ld
->ops
->set_power
)
110 ld
->ops
->set_power(ld
, power
);
111 mutex_unlock(&ld
->update_lock
);
114 extern struct lcd_device
*lcd_device_register(const char *name
,
115 struct device
*parent
, void *devdata
, struct lcd_ops
*ops
);
116 extern struct lcd_device
*devm_lcd_device_register(struct device
*dev
,
117 const char *name
, struct device
*parent
,
118 void *devdata
, struct lcd_ops
*ops
);
119 extern void lcd_device_unregister(struct lcd_device
*ld
);
120 extern void devm_lcd_device_unregister(struct device
*dev
,
121 struct lcd_device
*ld
);
123 #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
125 static inline void * lcd_get_data(struct lcd_device
*ld_dev
)
127 return dev_get_drvdata(&ld_dev
->dev
);