Add support for powering down the LCD (saves 50 mA when disabled)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20547 a1c6a512-1295-4272-9138-f99709370657

firmware/export/config-mrobe500.h

@@ -72,7 +72,17 @@
 #define LCD_PIXELFORMAT RGB565 /* rgb565 */
 
 /* Define this if your LCD can be enabled/disabled */
-//#define HAVE_LCD_ENABLE
+#define HAVE_LCD_ENABLE
+
+#define HAVE_LCD_SLEEP_SETTING
+
+/* Define this if your LCD can be put to sleep. HAVE_LCD_ENABLE
+   should be defined as well. */
+#define HAVE_LCD_SLEEP
+
+/* We don't use a setting but a fixed delay after the backlight has
+ * turned off */
+#define LCD_SLEEP_TIMEOUT (5*HZ)
 
 /* remote LCD */
 //#define HAVE_REMOTE_LCD

firmware/target/arm/tms320dm320/mrobe-500/backlight-mr500.c

@@ -30,12 +30,22 @@
 
 void _backlight_on(void)
 {
+#ifdef HAVE_LCD_SLEEP
+    backlight_lcd_sleep_countdown(false); /* stop counter */
+#endif
+#ifdef HAVE_LCD_ENABLE
+    lcd_enable(true); /* power on lcd + visible display */
+#endif
     _backlight_set_brightness(DEFAULT_BRIGHTNESS_SETTING);
 }
 
 void _backlight_off(void)
 {
     _backlight_set_brightness(0);
+#ifdef HAVE_LCD_SLEEP
+    /* Disable lcd after fade completes (when lcd_sleep timeout expires) */
+    backlight_lcd_sleep_countdown(true); /* start countdown */
+#endif
 }
 
 /* Assumes that the backlight has been initialized */

firmware/target/arm/tms320dm320/mrobe-500/lcd-mr500.c

@@ -38,7 +38,11 @@
 extern void lcd_copy_buffer_rect(fb_data *dst, const fb_data *src,
                                  int width, int height);
 
-static volatile bool lcd_on = true;
+static bool lcd_on = true;
+#if defined(HAVE_LCD_ENABLE) || defined(HAVE_LCD_SLEEP)
+static bool lcd_powered = true;
+#endif
+
 volatile bool lcd_poweroff = false;
 /*
 ** These are imported from lcd-16bit.c
@@ -46,10 +50,55 @@ volatile bool lcd_poweroff = false;
 extern unsigned fg_pattern;
 extern unsigned bg_pattern;
 
+#if defined(HAVE_LCD_ENABLE) || defined(HAVE_LCD_SLEEP)
 bool lcd_active(void)
 {
     return lcd_on;
 }
+#endif
+
+#if defined(HAVE_LCD_SLEEP)
+void lcd_sleep()
+{
+    if (lcd_powered)
+    {
+        /* "not powered" implies "disabled" */
+        if (lcd_on)
+            lcd_enable(false);
+    	IO_GIO_BITCLR2=1<<4;
+    	lcd_powered=false;
+    }
+}
+#endif
+
+#if defined(HAVE_LCD_ENABLE)
+void lcd_enable(bool state)
+{
+    if (state == lcd_on)
+        return;
+
+    if(state)
+    {
+        /* "enabled" implies "powered" */
+        if (!lcd_powered)
+        {
+        	lcd_powered=true;
+            IO_GIO_BITSET2=1<<4;
+            /* Wait long enough for a frame to be written - yes, it
+             * takes awhile. */
+            sleep(HZ/5);
+        }
+
+        lcd_on = true;
+        lcd_update();
+        lcd_activation_call_hook();
+    }
+    else 
+    {
+        lcd_on = false;
+    }
+}
+#endif
 
 /* LCD init - based on code from ingenient-bsp/bootloader/board/dm320/splash.c
  *  and code by Catalin Patulea from the M:Robe 500i linux port
@@ -80,6 +129,9 @@ void lcd_init_device(void)
     IO_OSD_OSDWIN0YP=0;
     IO_OSD_OSDWIN0XL=480;
     IO_OSD_OSDWIN0YL=640;
+    
+    /* Set pin 36 to an output */
+    IO_GIO_DIR2&=!(1<<4);
 }
 
 /* Update a fraction of the display. */
@@ -138,11 +190,6 @@ void lcd_update_rect(int x, int y, int width, int height)
 #endif
 }
 
-void lcd_enable(bool state)
-{
-    (void)state;
-}
-
 /* Update the display.
    This must be called after all other LCD functions that change the display. */
 void lcd_update(void)