clk: arm: sunxi: Add a new clock driver for sunxi SOCs

This commit implements the base CPU clocks for sunxi devices. It has
been tested using a slightly modified cpufreq driver from the
linux-sunxi 3.0 tree.

Additionally, document the new bindings introduced by this patch.

Idling:
    / # cat /sys/kernel/debug/clk/clk_summary
       clock                        enable_cnt  prepare_cnt  rate
    ---------------------------------------------------------------------
     osc32k                         0           0            32768
     osc24M_fixed                   0           0            24000000
        osc24M                      0           0            24000000
           apb1_mux                 0           0            24000000
              apb1                  0           0            24000000
           pll1                     0           0            60000000
              cpu                   0           0            60000000
                 axi                0           0            60000000
                    ahb             0           0            60000000
                       apb0         0           0            30000000
     dummy                          0           0            0

After "yes >/dev/null &":
    / # cat /sys/kernel/debug/clk/clk_summary
       clock                        enable_cnt  prepare_cnt  rate
    ---------------------------------------------------------------------
     osc32k                         0           0            32768
     osc24M_fixed                   0           0            24000000
        osc24M                      0           0            24000000
           apb1_mux                 0           0            24000000
              apb1                  0           0            24000000
           pll1                     0           0            1008000000
              cpu                   0           0            1008000000
                 axi                0           0            336000000
                    ahb             0           0            168000000
                       apb0         0           0            84000000
     dummy                          0           0            0

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
new file mode 100644
index 0000000..f49851c
--- /dev/null
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -0,0 +1,27 @@
+#ifndef __MACH_SUNXI_CLK_FACTORS_H
+#define __MACH_SUNXI_CLK_FACTORS_H
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+#define SUNXI_FACTORS_NOT_APPLICABLE	(0)
+
+struct clk_factors_config {
+	u8 nshift;
+	u8 nwidth;
+	u8 kshift;
+	u8 kwidth;
+	u8 mshift;
+	u8 mwidth;
+	u8 pshift;
+	u8 pwidth;
+};
+
+struct clk *clk_register_factors(struct device *dev, const char *name,
+				 const char *parent_name,
+				 unsigned long flags, void __iomem *reg,
+				 struct clk_factors_config *config,
+				 void (*get_factors) (u32 *rate, u32 parent_rate,
+						      u8 *n, u8 *k, u8 *m, u8 *p),
+				 spinlock_t *lock);
+#endif