1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * LCD Lowlevel Control Abstraction 4 * 5 * Copyright (C) 2003,2004 Hewlett-Packard Company 6 * 7 */ 8 9 #ifndef _LINUX_LCD_H 10 #define _LINUX_LCD_H 11 12 #include <linux/device.h> 13 #include <linux/mutex.h> 14 #include <linux/notifier.h> 15 #include <linux/fb.h> 16 17 #define LCD_POWER_ON (0) 18 #define LCD_POWER_REDUCED (1) // deprecated; don't use in new code 19 #define LCD_POWER_REDUCED_VSYNC_SUSPEND (2) // deprecated; don't use in new code 20 #define LCD_POWER_OFF (4) 21 22 /* Notes on locking: 23 * 24 * lcd_device->ops_lock is an internal backlight lock protecting the ops 25 * field and no code outside the core should need to touch it. 26 * 27 * Access to set_power() is serialised by the update_lock mutex since 28 * most drivers seem to need this and historically get it wrong. 29 * 30 * Most drivers don't need locking on their get_power() method. 31 * If yours does, you need to implement it in the driver. You can use the 32 * update_lock mutex if appropriate. 33 * 34 * Any other use of the locks below is probably wrong. 35 */ 36 37 struct lcd_device; 38 struct fb_info; 39 40 struct lcd_properties { 41 /* The maximum value for contrast (read-only) */ 42 int max_contrast; 43 }; 44 45 struct lcd_ops { 46 /* Get the LCD panel power status (0: full on, 1..3: controller 47 power on, flat panel power off, 4: full off), see FB_BLANK_XXX */ 48 int (*get_power)(struct lcd_device *); 49 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ 50 int (*set_power)(struct lcd_device *, int power); 51 /* Get the current contrast setting (0-max_contrast) */ 52 int (*get_contrast)(struct lcd_device *); 53 /* Set LCD panel contrast */ 54 int (*set_contrast)(struct lcd_device *, int contrast); 55 /* Set LCD panel mode (resolutions ...) */ 56 int (*set_mode)(struct lcd_device *, struct fb_videomode *); 57 /* Check if given framebuffer device is the one LCD is bound to; 58 return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */ 59 int (*check_fb)(struct lcd_device *, struct fb_info *); 60 }; 61 62 struct lcd_device { 63 struct lcd_properties props; 64 /* This protects the 'ops' field. If 'ops' is NULL, the driver that 65 registered this device has been unloaded, and if class_get_devdata() 66 points to something in the body of that driver, it is also invalid. */ 67 struct mutex ops_lock; 68 /* If this is NULL, the backing module is unloaded */ 69 const struct lcd_ops *ops; 70 /* Serialise access to set_power method */ 71 struct mutex update_lock; 72 /* The framebuffer notifier block */ 73 struct notifier_block fb_notif; 74 75 struct device dev; 76 }; 77 78 struct lcd_platform_data { 79 /* reset lcd panel device. */ 80 int (*reset)(struct lcd_device *ld); 81 /* on or off to lcd panel. if 'enable' is 0 then 82 lcd power off and 1, lcd power on. */ 83 int (*power_on)(struct lcd_device *ld, int enable); 84 85 /* it indicates whether lcd panel was enabled 86 from bootloader or not. */ 87 int lcd_enabled; 88 /* it means delay for stable time when it becomes low to high 89 or high to low that is dependent on whether reset gpio is 90 low active or high active. */ 91 unsigned int reset_delay; 92 /* stable time needing to become lcd power on. */ 93 unsigned int power_on_delay; 94 /* stable time needing to become lcd power off. */ 95 unsigned int power_off_delay; 96 97 /* it could be used for any purpose. */ 98 void *pdata; 99 }; 100 101 static inline void lcd_set_power(struct lcd_device *ld, int power) 102 { 103 mutex_lock(&ld->update_lock); 104 if (ld->ops && ld->ops->set_power) 105 ld->ops->set_power(ld, power); 106 mutex_unlock(&ld->update_lock); 107 } 108 109 extern struct lcd_device *lcd_device_register(const char *name, 110 struct device *parent, void *devdata, const struct lcd_ops *ops); 111 extern struct lcd_device *devm_lcd_device_register(struct device *dev, 112 const char *name, struct device *parent, 113 void *devdata, const struct lcd_ops *ops); 114 extern void lcd_device_unregister(struct lcd_device *ld); 115 extern void devm_lcd_device_unregister(struct device *dev, 116 struct lcd_device *ld); 117 118 #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev) 119 120 static inline void * lcd_get_data(struct lcd_device *ld_dev) 121 { 122 return dev_get_drvdata(&ld_dev->dev); 123 } 124 125 126 #endif 127