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>

1 files changed, 44 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
new file mode 100644
index 00000000000..b23cfbdbcd6
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -0,0 +1,44 @@
+Device Tree Clock bindings for arch-sunxi
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be one of the following:
+	"allwinner,sunxi-osc-clk" - for a gatable oscillator
+	"allwinner,sunxi-pll1-clk" - for the main PLL clock
+	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
+	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
+	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
+	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
+	"allwinner,sunxi-apb1-clk" - for the sunxi APB1 clock
+	"allwinner,sunxi-apb1-mux-clk" - for the sunxi APB1 clock muxing
+
+Required properties for all clocks:
+- reg : shall be the control register address for the clock.
+- clocks : shall be the input parent clock(s) phandle for the clock
+- #clock-cells : from common clock binding; shall be set to 0.
+
+For example:
+
+osc24M: osc24M@01c20050 {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-osc-clk";
+	reg = <0x01c20050 0x4>;
+	clocks = <&osc24M_fixed>;
+};
+
+pll1: pll1@01c20000 {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-pll1-clk";
+	reg = <0x01c20000 0x4>;
+	clocks = <&osc24M>;
+};
+
+cpu: cpu@01c20054 {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-cpu-clk";
+	reg = <0x01c20054 0x4>;
+	clocks = <&osc32k>, <&osc24M>, <&pll1>;
+};