ARM: SAMSUNG: Add support for handling of cpu revision

This patch adds plat-samsung/cpu.c for detecting of cpu id and
silicon revision.

This patch was originally from Changhwan Youn <chaos.youn@samsung.com>

Acked-by: Changhwan Youn <chaos.youn@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/cpu.c b/arch/arm/plat-samsung/cpu.c
new file mode 100644
index 000000000000..81c06d44c11e
--- /dev/null
+++ b/arch/arm/plat-samsung/cpu.c
@@ -0,0 +1,58 @@
+/* linux/arch/arm/plat-samsung/cpu.c
+ *
+ * Copyright (c) 2009-2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Samsung CPU 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <asm/system.h>
+
+#include <mach/map.h>
+#include <plat/cpu.h>
+
+unsigned long samsung_cpu_id;
+static unsigned int samsung_cpu_rev;
+
+unsigned int samsung_rev(void)
+{
+	return samsung_cpu_rev;
+}
+EXPORT_SYMBOL(samsung_rev);
+
+void __init s3c24xx_init_cpu(void)
+{
+	/* nothing here yet */
+
+	samsung_cpu_rev = 0;
+}
+
+void __init s3c64xx_init_cpu(void)
+{
+	samsung_cpu_id = __raw_readl(S3C_VA_SYS + 0x118);
+	if (!samsung_cpu_id) {
+		/*
+		 * 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);
+		samsung_cpu_id = __raw_readl(S3C_VA_SYS + 0xA1C);
+	}
+
+	samsung_cpu_rev = 0;
+}
+
+void __init s5p_init_cpu(void __iomem *cpuid_addr)
+{
+	samsung_cpu_id = __raw_readl(cpuid_addr);
+	samsung_cpu_rev = samsung_cpu_id & 0xFF;
+}