Don't enable the current sink for the Clip Zip backlight until its actually needed.

Patch by Mihail Zenkov who measured a modest increase in power consumption with
the current sink enabled.

Change-Id: Ib1c1639318de35d449ca51a9bd480005cb6a2ee0
Reviewed-on: http://gerrit.rockbox.org/989
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>
Tested: Michael Giacomelli <giac2000@hotmail.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/firmware/target/arm/as3525/sansa-clipzip/backlight-clipzip.c b/firmware/target/arm/as3525/sansa-clipzip/backlight-clipzip.c
index fd44d76cac..a47941bbd7 100644
--- a/firmware/target/arm/as3525/sansa-clipzip/backlight-clipzip.c
+++ b/firmware/target/arm/as3525/sansa-clipzip/backlight-clipzip.c
@@ -29,16 +29,14 @@
 
 bool _backlight_init()
 {
-    /* GPIO B1 controls backlight */
-    GPIOB_DIR |= (1 << 1);
-    ascodec_write_pmu(AS3543_BACKLIGHT, 1, 0x91);
-    GPIOB_PIN(1) = (1 << 1);
-    
     return true;
 }
 
 void _backlight_on(void)
 {
+    /* GPIO B1 controls backlight */
+    GPIOB_DIR |= (1 << 1);
+    ascodec_write_pmu(AS3543_BACKLIGHT, 1, 0x90);
     GPIOB_PIN(1) = (1 << 1);
 #ifdef HAVE_LCD_ENABLE
     lcd_enable(true);
@@ -50,6 +48,7 @@ void _backlight_off(void)
 #ifdef HAVE_LCD_ENABLE
     lcd_enable(false);
 #endif
+    ascodec_write_pmu(AS3543_BACKLIGHT, 1, 0);
     GPIOB_PIN(1) = 0;
 }