[ARM] 4516/1: S3C: Fix uncompressor serial output for ARM926

Ensure we check for ARM926 in the uncompressor, as all current
ARM926s do not have an ID register and all have S3C2440 style
UARTs.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

include/asm-arm/arch-s3c2410/uncompress.h

@@ -25,6 +25,15 @@
 /* how many bytes we allow into the FIFO at a time in FIFO mode */
 #define FIFO_MAX	 (14)
 
+static inline int is_arm926(void)
+{
+	unsigned int cpuid;
+
+	asm volatile ("mrc p15, 0, %0, c1, c0, 0" : "=r" (cpuid));
+
+	return ((cpuid & 0xff0) == 0x260);
+}
+
 static void arch_detect_cpu(void)
 {
 	unsigned int cpuid;
@@ -32,7 +41,7 @@ static void arch_detect_cpu(void)
 	cpuid = *((volatile unsigned int *)S3C2410_GSTATUS1);
 	cpuid &= S3C2410_GSTATUS1_IDMASK;
 
-	if (cpuid == S3C2410_GSTATUS1_2440 ||
+	if (is_arm926() || cpuid == S3C2410_GSTATUS1_2440 ||
 	    cpuid == S3C2410_GSTATUS1_2442) {
 		fifo_mask = S3C2440_UFSTAT_TXMASK;
 		fifo_max = 63 << S3C2440_UFSTAT_TXSHIFT;