zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/arch/arm/mach-s3c2440/dsc.c b/ap/os/linux/linux-3.4.x/arch/arm/mach-s3c2440/dsc.c
new file mode 100644
index 0000000..9ea66e3
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/arch/arm/mach-s3c2440/dsc.c
@@ -0,0 +1,54 @@
+/* linux/arch/arm/mach-s3c2440/dsc.c
+ *
+ * Copyright (c) 2004-2005 Simtec Electronics
+ *   Ben Dooks <ben@simtec.co.uk>
+ *
+ * Samsung S3C2440 Drive Strength Control support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/io.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+#include <asm/mach/irq.h>
+
+#include <mach/hardware.h>
+#include <asm/irq.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/regs-dsc.h>
+
+#include <plat/cpu.h>
+#include <plat/s3c244x.h>
+
+int s3c2440_set_dsc(unsigned int pin, unsigned int value)
+{
+	void __iomem *base;
+	unsigned long val;
+	unsigned long flags;
+	unsigned long mask;
+
+	base = (pin & S3C2440_SELECT_DSC1) ? S3C2440_DSC1 : S3C2440_DSC0;
+	mask = 3 << S3C2440_DSC_GETSHIFT(pin);
+
+	local_irq_save(flags);
+
+	val = __raw_readl(base);
+	val &= ~mask;
+	val |= value & mask;
+	__raw_writel(val, base);
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+EXPORT_SYMBOL(s3c2440_set_dsc);