diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/backlight.h | 50 | ||||
| -rw-r--r-- | include/linux/fb.h | 13 | ||||
| -rw-r--r-- | include/linux/lcd.h | 45 |
3 files changed, 81 insertions, 27 deletions
diff --git a/include/linux/backlight.h b/include/linux/backlight.h index a5cf1beacb4..1023ba0d6e5 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -9,17 +9,28 @@ #define _LINUX_BACKLIGHT_H #include <linux/device.h> +#include <linux/mutex.h> #include <linux/notifier.h> +/* Notes on locking: + * + * backlight_device->ops_lock is an internal backlight lock protecting the + * ops pointer and no code outside the core should need to touch it. + * + * Access to update_status() is serialised by the update_lock mutex since + * most drivers seem to need this and historically get it wrong. + * + * Most drivers don't need locking on their get_brightness() method. + * If yours does, you need to implement it in the driver. You can use the + * update_lock mutex if appropriate. + * + * Any other use of the locks below is probably wrong. + */ + struct backlight_device; struct fb_info; -/* This structure defines all the properties of a backlight - (usually attached to a LCD). */ -struct backlight_properties { - /* Owner module */ - struct module *owner; - +struct backlight_ops { /* Notify the backlight driver some property has changed */ int (*update_status)(struct backlight_device *); /* Return the current backlight brightness (accounting for power, @@ -28,7 +39,10 @@ struct backlight_properties { /* Check if given framebuffer device is the one bound to this backlight; return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */ int (*check_fb)(struct fb_info *); +}; +/* This structure defines all the properties of a backlight */ +struct backlight_properties { /* Current User requested brightness (0 - max_brightness) */ int brightness; /* Maximal value for brightness (read-only) */ @@ -41,20 +55,34 @@ struct backlight_properties { }; struct backlight_device { - /* This protects the 'props' field. If 'props' is NULL, the driver that + /* Backlight properties */ + struct backlight_properties props; + + /* Serialise access to update_status method */ + struct mutex update_lock; + + /* This protects the 'ops' field. If 'ops' is NULL, the driver that registered this device has been unloaded, and if class_get_devdata() points to something in the body of that driver, it is also invalid. */ - struct semaphore sem; - /* If this is NULL, the backing module is unloaded */ - struct backlight_properties *props; + struct mutex ops_lock; + struct backlight_ops *ops; + /* The framebuffer notifier block */ struct notifier_block fb_notif; /* The class device structure */ struct class_device class_dev; }; +static inline void backlight_update_status(struct backlight_device *bd) +{ + mutex_lock(&bd->update_lock); + if (bd->ops && bd->ops->update_status) + bd->ops->update_status(bd); + mutex_unlock(&bd->update_lock); +} + extern struct backlight_device *backlight_device_register(const char *name, - struct device *dev,void *devdata,struct backlight_properties *bp); + struct device *dev, void *devdata, struct backlight_ops *ops); extern void backlight_device_unregister(struct backlight_device *bd); #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev) diff --git a/include/linux/fb.h b/include/linux/fb.h index a78e25683f8..be913ec8716 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -516,13 +516,15 @@ struct fb_cursor_user { #define FB_EVENT_GET_CONSOLE_MAP 0x07 /* CONSOLE-SPECIFIC: set console to framebuffer mapping */ #define FB_EVENT_SET_CONSOLE_MAP 0x08 -/* A display blank is requested */ +/* A hardware display blank change occured */ #define FB_EVENT_BLANK 0x09 /* Private modelist is to be replaced */ #define FB_EVENT_NEW_MODELIST 0x0A /* The resolution of the passed in fb_info about to change and all vc's should be changed */ #define FB_EVENT_MODE_CHANGE_ALL 0x0B +/* A software display blank change occured */ +#define FB_EVENT_CONBLANK 0x0C struct fb_event { struct fb_info *info; @@ -767,16 +769,13 @@ struct fb_info { struct fb_videomode *mode; /* current mode */ #ifdef CONFIG_FB_BACKLIGHT - /* Lock ordering: - * bl_mutex (protects bl_dev and bl_curve) - * bl_dev->sem (backlight class) - */ - struct mutex bl_mutex; - /* assigned backlight device */ + /* set before framebuffer registration, + remove after unregister */ struct backlight_device *bl_dev; /* Backlight level curve */ + struct mutex bl_curve_mutex; u8 bl_curve[FB_BACKLIGHT_LEVELS]; #endif diff --git a/include/linux/lcd.h b/include/linux/lcd.h index d739b2e7eac..598793c0745 100644 --- a/include/linux/lcd.h +++ b/include/linux/lcd.h @@ -9,22 +9,38 @@ #define _LINUX_LCD_H #include <linux/device.h> +#include <linux/mutex.h> #include <linux/notifier.h> +/* Notes on locking: + * + * lcd_device->ops_lock is an internal backlight lock protecting the ops + * field and no code outside the core should need to touch it. + * + * Access to set_power() is serialised by the update_lock mutex since + * most drivers seem to need this and historically get it wrong. + * + * Most drivers don't need locking on their get_power() method. + * If yours does, you need to implement it in the driver. You can use the + * update_lock mutex if appropriate. + * + * Any other use of the locks below is probably wrong. + */ + struct lcd_device; struct fb_info; -/* This structure defines all the properties of a LCD flat panel. */ struct lcd_properties { - /* Owner module */ - struct module *owner; + /* The maximum value for contrast (read-only) */ + int max_contrast; +}; + +struct lcd_ops { /* Get the LCD panel power status (0: full on, 1..3: controller power on, flat panel power off, 4: full off), see FB_BLANK_XXX */ int (*get_power)(struct lcd_device *); /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ int (*set_power)(struct lcd_device *, int power); - /* The maximum value for contrast (read-only) */ - int max_contrast; /* Get the current contrast setting (0-max_contrast) */ int (*get_contrast)(struct lcd_device *); /* Set LCD panel contrast */ @@ -35,20 +51,31 @@ struct lcd_properties { }; struct lcd_device { - /* This protects the 'props' field. If 'props' is NULL, the driver that + struct lcd_properties props; + /* This protects the 'ops' field. If 'ops' is NULL, the driver that registered this device has been unloaded, and if class_get_devdata() points to something in the body of that driver, it is also invalid. */ - struct semaphore sem; + struct mutex ops_lock; /* If this is NULL, the backing module is unloaded */ - struct lcd_properties *props; + struct lcd_ops *ops; + /* Serialise access to set_power method */ + struct mutex update_lock; /* The framebuffer notifier block */ struct notifier_block fb_notif; /* The class device structure */ struct class_device class_dev; }; +static inline void lcd_set_power(struct lcd_device *ld, int power) +{ + mutex_lock(&ld->update_lock); + if (ld->ops && ld->ops->set_power) + ld->ops->set_power(ld, power); + mutex_unlock(&ld->update_lock); +} + extern struct lcd_device *lcd_device_register(const char *name, - void *devdata, struct lcd_properties *lp); + void *devdata, struct lcd_ops *ops); extern void lcd_device_unregister(struct lcd_device *ld); #define to_lcd_device(obj) container_of(obj, struct lcd_device, class_dev) |