1 /* 2 * LCD Lowlevel Control Abstraction 3 * 4 * Copyright (C) 2003,2004 Hewlett-Packard Company 5 * 6 */ 7 8 #ifndef _LINUX_LCD_H 9 #define _LINUX_LCD_H 10 11 #include <linux/device.h> 12 #include <linux/mutex.h> 13 #include <linux/notifier.h> 14 #include <linux/fb.h> 15 16 /* Notes on locking: 17 * 18 * lcd_device->ops_lock is an internal backlight lock protecting the ops 19 * field and no code outside the core should need to touch it. 20 * 21 * Access to set_power() is serialised by the update_lock mutex since 22 * most drivers seem to need this and historically get it wrong. 23 * 24 * Most drivers don't need locking on their get_power() method. 25 * If yours does, you need to implement it in the driver. You can use the 26 * update_lock mutex if appropriate. 27 * 28 * Any other use of the locks below is probably wrong. 29 */ 30 31 struct lcd_device; 32 struct fb_info; 33 34 struct lcd_properties { 35 /* The maximum value for contrast (read-only) */ 36 int max_contrast; 37 }; 38 39 struct lcd_ops { 40 /* Get the LCD panel power status (0: full on, 1..3: controller 41 power on, flat panel power off, 4: full off), see FB_BLANK_XXX */ 42 int (*get_power)(struct lcd_device *); 43 /* 44 * Enable or disable power to the LCD(0: on; 4: off, see FB_BLANK_XXX) 45 * and this callback would be called proir to fb driver's callback. 46 * 47 * P.S. note that if early_set_power is not NULL then early fb notifier 48 * would be registered. 49 */ 50 int (*early_set_power)(struct lcd_device *, int power); 51 /* revert the effects of the early blank event. */ 52 int (*r_early_set_power)(struct lcd_device *, int power); 53 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ 54 int (*set_power)(struct lcd_device *, int power); 55 /* Get the current contrast setting (0-max_contrast) */ 56 int (*get_contrast)(struct lcd_device *); 57 /* Set LCD panel contrast */ 58 int (*set_contrast)(struct lcd_device *, int contrast); 59 /* Set LCD panel mode (resolutions ...) */ 60 int (*set_mode)(struct lcd_device *, struct fb_videomode *); 61 /* Check if given framebuffer device is the one LCD is bound to; 62 return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */ 63 int (*check_fb)(struct lcd_device *, struct fb_info *); 64 }; 65 66 struct lcd_device { 67 struct lcd_properties props; 68 /* This protects the 'ops' field. If 'ops' is NULL, the driver that 69 registered this device has been unloaded, and if class_get_devdata() 70 points to something in the body of that driver, it is also invalid. */ 71 struct mutex ops_lock; 72 /* If this is NULL, the backing module is unloaded */ 73 struct lcd_ops *ops; 74 /* Serialise access to set_power method */ 75 struct mutex update_lock; 76 /* The framebuffer notifier block */ 77 struct notifier_block fb_notif; 78 79 struct device dev; 80 }; 81 82 struct lcd_platform_data { 83 /* reset lcd panel device. */ 84 int (*reset)(struct lcd_device *ld); 85 /* on or off to lcd panel. if 'enable' is 0 then 86 lcd power off and 1, lcd power on. */ 87 int (*power_on)(struct lcd_device *ld, int enable); 88 89 /* it indicates whether lcd panel was enabled 90 from bootloader or not. */ 91 int lcd_enabled; 92 /* it means delay for stable time when it becomes low to high 93 or high to low that is dependent on whether reset gpio is 94 low active or high active. */ 95 unsigned int reset_delay; 96 /* stable time needing to become lcd power on. */ 97 unsigned int power_on_delay; 98 /* stable time needing to become lcd power off. */ 99 unsigned int power_off_delay; 100 101 /* it could be used for any purpose. */ 102 void *pdata; 103 }; 104 105 static inline void lcd_set_power(struct lcd_device *ld, int power) 106 { 107 mutex_lock(&ld->update_lock); 108 if (ld->ops && ld->ops->set_power) 109 ld->ops->set_power(ld, power); 110 mutex_unlock(&ld->update_lock); 111 } 112 113 extern struct lcd_device *lcd_device_register(const char *name, 114 struct device *parent, void *devdata, struct lcd_ops *ops); 115 extern struct lcd_device *devm_lcd_device_register(struct device *dev, 116 const char *name, struct device *parent, 117 void *devdata, struct lcd_ops *ops); 118 extern void lcd_device_unregister(struct lcd_device *ld); 119 extern void devm_lcd_device_unregister(struct device *dev, 120 struct lcd_device *ld); 121 122 #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev) 123 124 static inline void * lcd_get_data(struct lcd_device *ld_dev) 125 { 126 return dev_get_drvdata(&ld_dev->dev); 127 } 128 129 130 #endif 131