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git.proxmox.com Git - mirror_ubuntu-jammy-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
*);
44 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
45 int (*set_power
)(struct lcd_device
*, int power
);
46 /* Get the current contrast setting (0-max_contrast) */
47 int (*get_contrast
)(struct lcd_device
*);
48 /* Set LCD panel contrast */
49 int (*set_contrast
)(struct lcd_device
*, int contrast
);
50 /* Set LCD panel mode (resolutions ...) */
51 int (*set_mode
)(struct lcd_device
*, struct fb_videomode
*);
52 /* Check if given framebuffer device is the one LCD is bound to;
53 return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
54 int (*check_fb
)(struct lcd_device
*, struct fb_info
*);
58 struct lcd_properties props
;
59 /* This protects the 'ops' field. If 'ops' is NULL, the driver that
60 registered this device has been unloaded, and if class_get_devdata()
61 points to something in the body of that driver, it is also invalid. */
62 struct mutex ops_lock
;
63 /* If this is NULL, the backing module is unloaded */
65 /* Serialise access to set_power method */
66 struct mutex update_lock
;
67 /* The framebuffer notifier block */
68 struct notifier_block fb_notif
;
73 struct lcd_platform_data
{
74 /* reset lcd panel device. */
75 int (*reset
)(struct lcd_device
*ld
);
76 /* on or off to lcd panel. if 'enable' is 0 then
77 lcd power off and 1, lcd power on. */
78 int (*power_on
)(struct lcd_device
*ld
, int enable
);
80 /* it indicates whether lcd panel was enabled
81 from bootloader or not. */
83 /* it means delay for stable time when it becomes low to high
84 or high to low that is dependent on whether reset gpio is
85 low active or high active. */
86 unsigned int reset_delay
;
87 /* stable time needing to become lcd power on. */
88 unsigned int power_on_delay
;
89 /* stable time needing to become lcd power off. */
90 unsigned int power_off_delay
;
92 /* it could be used for any purpose. */
96 static inline void lcd_set_power(struct lcd_device
*ld
, int power
)
98 mutex_lock(&ld
->update_lock
);
99 if (ld
->ops
&& ld
->ops
->set_power
)
100 ld
->ops
->set_power(ld
, power
);
101 mutex_unlock(&ld
->update_lock
);
104 extern struct lcd_device
*lcd_device_register(const char *name
,
105 struct device
*parent
, void *devdata
, struct lcd_ops
*ops
);
106 extern struct lcd_device
*devm_lcd_device_register(struct device
*dev
,
107 const char *name
, struct device
*parent
,
108 void *devdata
, struct lcd_ops
*ops
);
109 extern void lcd_device_unregister(struct lcd_device
*ld
);
110 extern void devm_lcd_device_unregister(struct device
*dev
,
111 struct lcd_device
*ld
);
113 #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
115 static inline void * lcd_get_data(struct lcd_device
*ld_dev
)
117 return dev_get_drvdata(&ld_dev
->dev
);