Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 126 insertions, 0 deletions

diff --git a/kernel/arch/arm/mach-imx/clk-pllv1.c b/kernel/arch/arm/mach-imx/clk-pllv1.c
new file mode 100644
index 000000000..d21d14ca4
--- /dev/null
+++ b/kernel/arch/arm/mach-imx/clk-pllv1.c
@@ -0,0 +1,126 @@
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+
+#include "clk.h"
+#include "common.h"
+#include "hardware.h"
+
+/**
+ * pll v1
+ *
+ * @clk_hw	clock source
+ * @parent	the parent clock name
+ * @base	base address of pll registers
+ *
+ * PLL clock version 1, found on i.MX1/21/25/27/31/35
+ */
+
+#define MFN_BITS	(10)
+#define MFN_SIGN	(BIT(MFN_BITS - 1))
+#define MFN_MASK	(MFN_SIGN - 1)
+
+struct clk_pllv1 {
+	struct clk_hw	hw;
+	void __iomem	*base;
+};
+
+#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk))
+
+static inline bool mfn_is_negative(unsigned int mfn)
+{
+	return !cpu_is_mx1() && !cpu_is_mx21() && (mfn & MFN_SIGN);
+}
+
+static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clk_pllv1 *pll = to_clk_pllv1(hw);
+	long long ll;
+	int mfn_abs;
+	unsigned int mfi, mfn, mfd, pd;
+	u32 reg;
+	unsigned long rate;
+
+	reg = readl(pll->base);
+
+	/*
+	 * Get the resulting clock rate from a PLL register value and the input
+	 * frequency. PLLs with this register layout can be found on i.MX1,
+	 * i.MX21, i.MX27 and i,MX31
+	 *
+	 *                  mfi + mfn / (mfd + 1)
+	 *  f = 2 * f_ref * --------------------
+	 *                        pd + 1
+	 */
+
+	mfi = (reg >> 10) & 0xf;
+	mfn = reg & 0x3ff;
+	mfd = (reg >> 16) & 0x3ff;
+	pd =  (reg >> 26) & 0xf;
+
+	mfi = mfi <= 5 ? 5 : mfi;
+
+	mfn_abs = mfn;
+
+	/*
+	 * On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit
+	 * 2's complements number.
+	 * On i.MX27 the bit 9 is the sign bit.
+	 */
+	if (mfn_is_negative(mfn)) {
+		if (cpu_is_mx27())
+			mfn_abs = mfn & MFN_MASK;
+		else
+			mfn_abs = BIT(MFN_BITS) - mfn;
+	}
+
+	rate = parent_rate * 2;
+	rate /= pd + 1;
+
+	ll = (unsigned long long)rate * mfn_abs;
+
+	do_div(ll, mfd + 1);
+
+	if (mfn_is_negative(mfn))
+		ll = -ll;
+
+	ll = (rate * mfi) + ll;
+
+	return ll;
+}
+
+static struct clk_ops clk_pllv1_ops = {
+	.recalc_rate = clk_pllv1_recalc_rate,
+};
+
+struct clk *imx_clk_pllv1(const char *name, const char *parent,
+		void __iomem *base)
+{
+	struct clk_pllv1 *pll;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	pll = kmalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	pll->base = base;
+
+	init.name = name;
+	init.ops = &clk_pllv1_ops;
+	init.flags = 0;
+	init.parent_names = &parent;
+	init.num_parents = 1;
+
+	pll->hw.init = &init;
+
+	clk = clk_register(NULL, &pll->hw);
+	if (IS_ERR(clk))
+		kfree(pll);
+
+	return clk;
+}