[ARM] S3C64XX: Add PLL definitions

Add definitions for the s3c6400 epll and main pll
as well as functions to decode the rate. Add
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c64xx/include/plat/pll.h

+/* arch/arm/plat-s3c64xx/include/plat/pll.h
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *	http://armlinux.simtec.co.uk/
+ *
+ * S3C64XX PLL code
+ *
+ * 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.
+*/
+
+#define S3C6400_PLL_MDIV_MASK	((1 << (25-16)) - 1)
+#define S3C6400_PLL_PDIV_MASK	((1 << (13-8)) - 1)
+#define S3C6400_PLL_SDIV_MASK	((1 << (2-0)) - 1)
+#define S3C6400_PLL_MDIV_SHIFT	(16)
+#define S3C6400_PLL_PDIV_SHIFT	(8)
+#define S3C6400_PLL_SDIV_SHIFT	(0)
+
+#include <asm/div64.h>
+
+static inline unsigned long s3c6400_get_pll(unsigned long baseclk,
+					    u32 pllcon)
+{
+	u32 mdiv, pdiv, sdiv;
+	u64 fvco = baseclk;
+
+	mdiv = (pllcon >> S3C6400_PLL_MDIV_SHIFT) & S3C6400_PLL_MDIV_MASK;
+	pdiv = (pllcon >> S3C6400_PLL_PDIV_SHIFT) & S3C6400_PLL_PDIV_MASK;
+	sdiv = (pllcon >> S3C6400_PLL_SDIV_SHIFT) & S3C6400_PLL_SDIV_MASK;
+
+	fvco *= mdiv;
+	do_div(fvco, (pdiv << sdiv));
+
+	return (unsigned long)fvco;
+}
+
+#define S3C6400_EPLL_MDIV_MASK	((1 << (23-16)) - 1)
+#define S3C6400_EPLL_PDIV_MASK	((1 << (13-8)) - 1)
+#define S3C6400_EPLL_SDIV_MASK	((1 << (2-0)) - 1)
+#define S3C6400_EPLL_MDIV_SHIFT	(16)
+#define S3C6400_EPLL_PDIV_SHIFT	(8)
+#define S3C6400_EPLL_SDIV_SHIFT	(0)
+#define S3C6400_EPLL_KDIV_MASK  (0xffff)
+
+static inline unsigned long s3c6400_get_epll(unsigned long baseclk)
+{
+	unsigned long result;
+	u32 epll0 = __raw_readl(S3C_EPLL_CON0);
+	u32 epll1 = __raw_readl(S3C_EPLL_CON1);
+	u32 mdiv, pdiv, sdiv, kdiv;
+	u64 tmp;
+
+	mdiv = (epll0 >> S3C6400_EPLL_MDIV_SHIFT) & S3C6400_EPLL_MDIV_MASK;
+	pdiv = (epll0 >> S3C6400_EPLL_PDIV_SHIFT) & S3C6400_EPLL_PDIV_MASK;
+	sdiv = (epll0 >> S3C6400_EPLL_SDIV_SHIFT) & S3C6400_EPLL_SDIV_MASK;
+	kdiv = epll1 & S3C6400_EPLL_KDIV_MASK;
+
+	/* We need to multiple baseclk by mdiv (the integer part) and kdiv
+	 * which is in 2^16ths, so shift mdiv up (does not overflow) and
+	 * add kdiv before multiplying. The use of tmp is to avoid any
+	 * overflows before shifting bac down into result when multipling
+	 * by the mdiv and kdiv pair.
+	 */
+
+	tmp = baseclk;
+	tmp *= (mdiv << 16) + kdiv;
+	do_div(tmp, (pdiv << sdiv));
+	result = tmp >> 16;
+
+	return result;
+}