gpb-shadow.patch

Uboot常用的移植patches, 方便定制移植到s3c2440

GTA02v5 pulls the GPBn lines controlling the LEDs down too strongly.
Thus bit operations on GPB always contain a 0 in these bits. With
the addition of a shadow register, this problem is avoided.

- Werner

Index: u-boot/board/neo1973/gta02/gta02.c
===================================================================
--- u-boot.orig/board/neo1973/gta02/gta02.c
+++ u-boot/board/neo1973/gta02/gta02.c
@@ -75,6 +75,8 @@
  */
 int gta02_revision;
 
+static uint16_t gpb_shadow = 0; /* to work around GTA02v5 LED bug */
+
 int gta02_get_pcb_revision(void);
 
 static inline void delay (unsigned long loops)
@@ -452,6 +454,7 @@
 #else
 		gpio->GPBDAT &= ~(1 << 3);	/* GPB3 */
 #endif
+	gpio->GPBDAT |= gpb_shadow;
 }
 
 void neo1973_gsm(int on)
@@ -571,10 +574,14 @@
 	if (led > 2)
 		return;
 
-	if (on)
-		gpio->GPBDAT |= (1 << led);
-	else
-		gpio->GPBDAT &= ~(1 << led);
+	if (on) {
+		gpb_shadow |= (1 << led);
+		gpio->GPBDAT |= gpb_shadow;
+	}
+	else {
+		gpb_shadow &= ~(1 << led);
+		gpio->GPBDAT = (gpio->GPBDAT | gpb_shadow) & ~(1 << led);
+	}
 }
 
 /**