1 files changed, 8 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c64xx/cpu.c b/arch/arm/plat-s3c64xx/cpu.c
index f9fdaab32ab4..19f68b5f0d36 100644
--- a/arch/arm/plat-s3c64xx/cpu.c
+++ b/arch/arm/plat-s3c64xx/cpu.c
@@ -126,6 +126,14 @@ void __init s3c64xx_init_io(struct map_desc *mach_desc, int size)
         iotable_init(mach_desc, size);
 
         idcode = __raw_readl(S3C_VA_SYS + 0x118);
+        if (!idcode) {
+                /* S3C6400 has the ID register in a different place,
+                 * and needs a write before it can be read. */
+
+                __raw_writel(0x0, S3C_VA_SYS + 0xA1C);
+                idcode = __raw_readl(S3C_VA_SYS + 0xA1C);
+        }
+
         s3c_init_cpu(idcode, cpu_ids, ARRAY_SIZE(cpu_ids));
 }