A22:improve backlight driver

diff --git a/drivers/video/backlight/aw9364_bl.c b/drivers/video/backlight/aw9364_bl.c
index 82c8d22f903e824d20eb7400c6d27159fe50c2ff..4187df158d742d78c66a3a6fd9000f836e78b931 100755 (executable)
--- a/drivers/video/backlight/aw9364_bl.c
+++ b/drivers/video/backlight/aw9364_bl.c
@@ -42,6 +42,8 @@ struct aw9364_backlight_data {
        int suspend_flag;
        int shutdown_flag;
 #endif
+
+       spinlock_t bl_lock;
 };
 
 #ifdef CONFIG_HAS_EARLYSUSPEND
@@ -64,35 +66,32 @@ static int aw9364_backlight_set(struct backlight_device *bl, int brightness)
 {
        struct aw9364_backlight_data *data = bl_get_data(bl);
        int i,num_clk, num_clk_to, num_clk_from;
-       
-       if(data && data->pin_en)
-       gpio_request(data->pin_en, NULL);
-       else
-       return -1;
-       
+       unsigned long flags;
+               
        brightness = brightness & 0xff; //0-256
 
        num_clk_from = 16 -(data->current_brightness>>4);       
        num_clk_to = 16 -(brightness>>4);
-       num_clk = (16 + num_clk_to - num_clk_from)%16;          
-
+       num_clk = (16 + num_clk_to - num_clk_from)%16;
+       
+       
        if(brightness < 16)
        {
                gpio_direction_output(data->pin_en, GPIO_LOW);
                mdelay(3);
        }
        else {
-               for(i=0; i<num_clk; i++)
+               spin_lock_irqsave(&data->bl_lock, flags);
+               for(i=0; i<num_clk; i++)        //the wave should not be intterupted
                {
-                       gpio_direction_output(data->pin_en, GPIO_LOW);
-                       udelay(5);      
-                       gpio_direction_output(data->pin_en, GPIO_HIGH);
+                       gpio_set_value(data->pin_en, GPIO_LOW); 
+                       gpio_set_value(data->pin_en, GPIO_HIGH);
                        if(i==0)
-                       udelay(50);
-                       else 
-                       udelay(2);              
+                       udelay(30);     
                }
+               spin_unlock_irqrestore(&data->bl_lock, flags);
        }
+       
        DBG("%s:current_bl=%d,bl=%d,num_clk_to=%d,num_clk_from=%d,num_clk=%d\n",__FUNCTION__,
                data->current_brightness,brightness,num_clk_to,num_clk_from,num_clk);
 
@@ -194,6 +193,13 @@ static int aw9364_backlight_probe(struct platform_device *pdev)
        bl->props.brightness = BL_INIT_VALUE;
        bl->props.max_brightness= BL_SET;
 
+       if(data && data->pin_en)
+       gpio_request(data->pin_en, NULL);
+       else
+       return -1;
+
+       spin_lock_init(&data->bl_lock); 
+
        platform_set_drvdata(pdev, bl);
 
 #ifdef CONFIG_HAS_EARLYSUSPEND 
@@ -206,6 +212,9 @@ static int aw9364_backlight_probe(struct platform_device *pdev)
        g_aw9364_data = data;
 #endif
 
+       gpio_direction_output(data->pin_en, GPIO_LOW);
+       mdelay(3);
+
        backlight_update_status(bl);
        schedule_delayed_work(&data->work, msecs_to_jiffies(100));