clk: mxs: add mxs specific clocks

Add mxs specific clocks, pll, reference clock (PFD), integer divider
and fractional divider.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

drivers/clk/mxs/clk.c

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/spinlock.h>
+
+DEFINE_SPINLOCK(mxs_lock);
+
+int mxs_clk_wait(void __iomem *reg, u8 shift)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(10);
+
+	while (readl_relaxed(reg) & (1 << shift))
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+
+	return 0;
+}