Documentation/devicetree/bindings/clock/img,tz1090-pdc-cr.txt

Binding for TZ1090 PDC clocks.

This binding uses the common clock binding[1]. It represents the clocks
required to generate the 32KHz PDC clock used by the devices in the low power
domain:

          ___________
xtal1 ___| xtal1_div |____________________________
         |___________|  |    ________   xtal1_div
                        `--o| rtc_sw \____________
xtal3 ----------------------|________/  32khz

xtal1_div = xtal1 / (reg[26:16] + 1)
xtal3 = reg[30] ? xtal3 : xtal1_div


[1] Documentation/devicetree/bindings/clock/clock-bindings.txt

Required properties:
- compatible         : Shall be "img,tz1090-pdc-cr", "syscon".
- #clock-cells       : From common clock binding; shall be set to 1.
- reg                : Base address for registers controlling PDC clocks.
- clocks             : Clock specifiers for each input clock.
- clock-names        : Labels for each input clock specified in clocks.
                       Can contain the following entries:
                       "xtal1" : XTAL1 oscillator.
                       "xtal3" : XTAL3 32KHz oscillator.

Optional properties:
- clock-indices      : From common clock binding. Allows clock-output-names to
                       be sparse.
- clock-output-names : From common clock binding. May be used to name specific
                       output clocks so that other clock providers can find
                       the clocks by name before the provider has been
                       instantiated. Can contain:
                       "32khz"     : 32khz PDC clock.

Clock Specifier Definition:
- <1st-cell>: Output clock number. Use constants from
              <dt-bindings/clock/tz1090-pdc.h>.

Examples:
	pdc_cr: pdc_cr {
		compatible = "img,tz1090-pdc-cr", "syscon";
		#clock-cells = <1>;
		reg = <0x02006500 0x4>;	/* SOC_GPIO_CONTROL0 */
		clocks = <&xtal1>,
			 <&xtal3>;
		clock-names = "xtal1",
			      "xtal3";
	};

	ir {
		...
		clocks = <&pdc_cr CLK_PDC_32KHZ>,
			 <&top_cr CLK_TOP_PDC>;
		clock-names = "core", "sys";
		...
	};