Merge branch 'omap4-i2c-init' into omap-for-linus

1 files changed, 51 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/include/plat/pll6553x.h b/arch/arm/plat-samsung/include/plat/pll6553x.h
new file mode 100644
index 00000000000..b8b7e1d884f
--- /dev/null
+++ b/arch/arm/plat-samsung/include/plat/pll6553x.h
@@ -0,0 +1,51 @@
+/* arch/arm/plat-samsung/include/plat/pll6553x.h
+ *	partially from arch/arm/mach-s3c64xx/include/mach/pll.h
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *	http://armlinux.simtec.co.uk/
+ *
+ * Samsung PLL6553x 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.
+*/
+
+/* S3C6400 and compatible (S3C2416, etc.) EPLL code */
+
+#define PLL6553X_MDIV_MASK	((1 << (23-16)) - 1)
+#define PLL6553X_PDIV_MASK	((1 << (13-8)) - 1)
+#define PLL6553X_SDIV_MASK	((1 << (2-0)) - 1)
+#define PLL6553X_MDIV_SHIFT	(16)
+#define PLL6553X_PDIV_SHIFT	(8)
+#define PLL6553X_SDIV_SHIFT	(0)
+#define PLL6553X_KDIV_MASK	(0xffff)
+
+static inline unsigned long s3c_get_pll6553x(unsigned long baseclk,
+					     u32 pll0, u32 pll1)
+{
+	unsigned long result;
+	u32 mdiv, pdiv, sdiv, kdiv;
+	u64 tmp;
+
+	mdiv = (pll0 >> PLL6553X_MDIV_SHIFT) & PLL6553X_MDIV_MASK;
+	pdiv = (pll0 >> PLL6553X_PDIV_SHIFT) & PLL6553X_PDIV_MASK;
+	sdiv = (pll0 >> PLL6553X_SDIV_SHIFT) & PLL6553X_SDIV_MASK;
+	kdiv = pll1 & PLL6553X_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;
+}