X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Flinux%2Flcd.h;h=1d379787f2e78e4a1b56cb35c448e8e84ff39f38;hb=12debc4248a4a7f1873e47cda2cdd7faca80b099;hp=d739b2e7eac26a64fa215909cd552345463493e2;hpb=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2;p=linux-2.6-omap-h63xx.git

diff --git a/include/linux/lcd.h b/include/linux/lcd.h
index d739b2e7eac..1d379787f2e 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 */
@@ -35,22 +51,39 @@ 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;
+
+	struct device 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);
+	struct device *parent, 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)
+#define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
+
+static inline void * lcd_get_data(struct lcd_device *ld_dev)
+{
+	return dev_get_drvdata(&ld_dev->dev);
+}
+
 
 #endif