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,sun4i-a10-osc-clk" - for a gatable oscillator
	"allwinner,sun4i-a10-pll1-clk" - for the main PLL clock and PLL4
	"allwinner,sun6i-a31-pll1-clk" - for the main PLL clock on A31
	"allwinner,sun8i-a23-pll1-clk" - for the main PLL clock on A23
	"allwinner,sun4i-a10-pll5-clk" - for the PLL5 clock
	"allwinner,sun4i-a10-pll6-clk" - for the PLL6 clock
	"allwinner,sun6i-a31-pll6-clk" - for the PLL6 clock on A31
	"allwinner,sun4i-a10-cpu-clk" - for the CPU multiplexer clock
	"allwinner,sun4i-a10-axi-clk" - for the AXI clock
	"allwinner,sun8i-a23-axi-clk" - for the AXI clock on A23
	"allwinner,sun4i-a10-axi-gates-clk" - for the AXI gates
	"allwinner,sun4i-a10-ahb-clk" - for the AHB clock
	"allwinner,sun4i-a10-ahb-gates-clk" - for the AHB gates on A10
	"allwinner,sun5i-a13-ahb-gates-clk" - for the AHB gates on A13
	"allwinner,sun5i-a10s-ahb-gates-clk" - for the AHB gates on A10s
	"allwinner,sun7i-a20-ahb-gates-clk" - for the AHB gates on A20
	"allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
	"allwinner,sun6i-a31-ahb1-mux-clk" - for the AHB1 multiplexer on A31
	"allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
	"allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23
	"allwinner,sun4i-a10-apb0-clk" - for the APB0 clock
	"allwinner,sun6i-a31-apb0-clk" - for the APB0 clock on A31
	"allwinner,sun8i-a23-apb0-clk" - for the APB0 clock on A23
	"allwinner,sun4i-a10-apb0-gates-clk" - for the APB0 gates on A10
	"allwinner,sun5i-a13-apb0-gates-clk" - for the APB0 gates on A13
	"allwinner,sun5i-a10s-apb0-gates-clk" - for the APB0 gates on A10s
	"allwinner,sun6i-a31-apb0-gates-clk" - for the APB0 gates on A31
	"allwinner,sun7i-a20-apb0-gates-clk" - for the APB0 gates on A20
	"allwinner,sun8i-a23-apb0-gates-clk" - for the APB0 gates on A23
	"allwinner,sun4i-a10-apb1-clk" - for the APB1 clock
	"allwinner,sun4i-a10-apb1-mux-clk" - for the APB1 clock muxing
	"allwinner,sun4i-a10-apb1-gates-clk" - for the APB1 gates on A10
	"allwinner,sun5i-a13-apb1-gates-clk" - for the APB1 gates on A13
	"allwinner,sun5i-a10s-apb1-gates-clk" - for the APB1 gates on A10s
	"allwinner,sun6i-a31-apb1-gates-clk" - for the APB1 gates on A31
	"allwinner,sun7i-a20-apb1-gates-clk" - for the APB1 gates on A20
	"allwinner,sun8i-a23-apb1-gates-clk" - for the APB1 gates on A23
	"allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
	"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
	"allwinner,sun8i-a23-apb2-gates-clk" - for the APB2 gates on A23
	"allwinner,sun5i-a13-mbus-clk" - for the MBUS clock on A13
	"allwinner,sun4i-a10-mod0-clk" - for the module 0 family of clocks
	"allwinner,sun7i-a20-out-clk" - for the external output clocks
	"allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31

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. For
	multiplexed clocks, the list order must match the hardware
	programming order.
- #clock-cells : from common clock binding; shall be set to 0 except for
	"allwinner,*-gates-clk", "allwinner,sun4i-pll5-clk" and
	"allwinner,sun4i-pll6-clk" where it shall be set to 1
- clock-output-names : shall be the corresponding names of the outputs.
	If the clock module only has one output, the name shall be the
	module name.

And "allwinner,*-usb-clk" clocks also require:
- reset-cells : shall be set to 1

For "allwinner,sun7i-a20-gmac-clk", the parent clocks shall be fixed rate
dummy clocks at 25 MHz and 125 MHz, respectively. See example.

Clock consumers should specify the desired clocks they use with a
"clocks" phandle cell. Consumers that are using a gated clock should
provide an additional ID in their clock property. This ID is the
offset of the bit controlling this particular gate in the register.

For example:

osc24M: clk@01c20050 {
	#clock-cells = <0>;
	compatible = "allwinner,sun4i-a10-osc-clk";
	reg = <0x01c20050 0x4>;
	clocks = <&osc24M_fixed>;
	clock-output-names = "osc24M";
};

pll1: clk@01c20000 {
	#clock-cells = <0>;
	compatible = "allwinner,sun4i-a10-pll1-clk";
	reg = <0x01c20000 0x4>;
	clocks = <&osc24M>;
	clock-output-names = "pll1";
};

pll5: clk@01c20020 {
	#clock-cells = <1>;
	compatible = "allwinner,sun4i-pll5-clk";
	reg = <0x01c20020 0x4>;
	clocks = <&osc24M>;
	clock-output-names = "pll5_ddr", "pll5_other";
};

cpu: cpu@01c20054 {
	#clock-cells = <0>;
	compatible = "allwinner,sun4i-a10-cpu-clk";
	reg = <0x01c20054 0x4>;
	clocks = <&osc32k>, <&osc24M>, <&pll1>;
	clock-output-names = "cpu";
};

mmc0_clk: clk@01c20088 {
	#clock-cells = <0>;
	compatible = "allwinner,sun4i-mod0-clk";
	reg = <0x01c20088 0x4>;
	clocks = <&osc24M>, <&pll6 1>, <&pll5 1>;
	clock-output-names = "mmc0";
};

mii_phy_tx_clk: clk@2 {
	#clock-cells = <0>;
	compatible = "fixed-clock";
	clock-frequency = <25000000>;
	clock-output-names = "mii_phy_tx";
};

gmac_int_tx_clk: clk@3 {
	#clock-cells = <0>;
	compatible = "fixed-clock";
	clock-frequency = <125000000>;
	clock-output-names = "gmac_int_tx";
};

gmac_clk: clk@01c20164 {
	#clock-cells = <0>;
	compatible = "allwinner,sun7i-a20-gmac-clk";
	reg = <0x01c20164 0x4>;
	/*
	 * The first clock must be fixed at 25MHz;
	 * the second clock must be fixed at 125MHz
	 */
	clocks = <&mii_phy_tx_clk>, <&gmac_int_tx_clk>;
	clock-output-names = "gmac";
};