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 31struct lcd_device; 32struct fb_info; 33 34struct lcd_properties { 35 /* The maximum value for contrast (read-only) */ 36 int max_contrast; 37}; 38 39struct 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 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ 44 int (*set_power)(struct lcd_device *, int power); 45 /* Get the current contrast setting (0-max_contrast) */ 46 int (*get_contrast)(struct lcd_device *); 47 /* Set LCD panel contrast */ 48 int (*set_contrast)(struct lcd_device *, int contrast); 49 /* Set LCD panel mode (resolutions ...) */ 50 int (*set_mode)(struct lcd_device *, struct fb_videomode *); 51 /* Check if given framebuffer device is the one LCD is bound to; 52 return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */ 53 int (*check_fb)(struct lcd_device *, struct fb_info *); 54}; 55 56struct lcd_device { 57 struct lcd_properties props; 58 /* This protects the 'ops' field. If 'ops' is NULL, the driver that 59 registered this device has been unloaded, and if class_get_devdata() 60 points to something in the body of that driver, it is also invalid. */ 61 struct mutex ops_lock; 62 /* If this is NULL, the backing module is unloaded */ 63 struct lcd_ops *ops; 64 /* Serialise access to set_power method */ 65 struct mutex update_lock; 66 /* The framebuffer notifier block */ 67 struct notifier_block fb_notif; 68 69 struct device dev; 70}; 71 72struct lcd_platform_data { 73 /* reset lcd panel device. */ 74 int (*reset)(struct lcd_device *ld); 75 /* on or off to lcd panel. if 'enable' is 0 then 76 lcd power off and 1, lcd power on. */ 77 int (*power_on)(struct lcd_device *ld, int enable); 78 79 /* it indicates whether lcd panel was enabled 80 from bootloader or not. */ 81 int lcd_enabled; 82 /* it means delay for stable time when it becomes low to high 83 or high to low that is dependent on whether reset gpio is 84 low active or high active. */ 85 unsigned int reset_delay; 86 /* stable time needing to become lcd power on. */ 87 unsigned int power_on_delay; 88 /* stable time needing to become lcd power off. */ 89 unsigned int power_off_delay; 90 91 /* it could be used for any purpose. */ 92 void *pdata; 93}; 94 95static inline void lcd_set_power(struct lcd_device *ld, int power) 96{ 97 mutex_lock(&ld->update_lock); 98 if (ld->ops && ld->ops->set_power) 99 ld->ops->set_power(ld, power); 100 mutex_unlock(&ld->update_lock); 101} 102 103extern struct lcd_device *lcd_device_register(const char *name, 104 struct device *parent, void *devdata, struct lcd_ops *ops); 105extern void lcd_device_unregister(struct lcd_device *ld); 106 107#define to_lcd_device(obj) container_of(obj, struct lcd_device, dev) 108 109static inline void * lcd_get_data(struct lcd_device *ld_dev) 110{ 111 return dev_get_drvdata(&ld_dev->dev); 112} 113 114 115#endif 116