The TZ1090 PDC (PowerDown Controller) clock should be at 32.768KHz, and is generated either directly from the XTAL3 clock or by dividing the XTAL1 clock. Both the divide and the mux are in a single register which also contains GPIO output data, and may need to be used by other non-Linux cores and threads, so create a special clock binding for this clock.
It essentially has just two clock inputs, and two clock outputs. Signed-off-by: James Hogan <[email protected]> Cc: Mike Turquette <[email protected]> Cc: Rob Herring <[email protected]> Cc: Pawel Moll <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Ian Campbell <[email protected]> Cc: Kumar Gala <[email protected]> Cc: [email protected] Cc: [email protected] --- .../bindings/clock/img,tz1090-pdc-clock.txt | 44 ++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/img,tz1090-pdc-clock.txt diff --git a/Documentation/devicetree/bindings/clock/img,tz1090-pdc-clock.txt b/Documentation/devicetree/bindings/clock/img,tz1090-pdc-clock.txt new file mode 100644 index 0000000..68e2eee --- /dev/null +++ b/Documentation/devicetree/bindings/clock/img,tz1090-pdc-clock.txt @@ -0,0 +1,44 @@ +Binding for TZ1090 PDC clock. + +This binding uses the common clock binding[1]. It has two input clocks +(clocks[0..1]), two output clocks (out[0..1]), and a memory-mapped register +(reg) controlling a divider and a mux atomically with respect to other fields +and (non-Linux) threads or cores. + + _____ +clocks[0] ___| div |______________________ + |_____| | ____ out[0] + `--o| sw \__________ +clocks[1] ----------------|____/ out[1] + + +out[0] = clocks[0] / (reg[26:16] + 1) +out[1] = reg[30] ? clocks[1] : out[0] + + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : shall be "img,tz1090-pdc-clock". +- #clock-cells : from common clock binding; shall be set to 1. +- reg : base address for register controlling mux and divider +- clocks : clock specifiers of two parent clocks +- clock-output-names : from common clock binding. Name of two output clocks. + +Clock Specifier Definition: +- <1st-cell>: output clock number. + +Examples: + /* ___________ + * xtal1 ___| xtal1_div |____________________________ + * |___________| | ________ xtal1_div + * `--o| rtc_sw \____________ + * xtal3 ----------------------|________/ 32khz + */ + pdc_clk { + compatible = "img,tz1090-pdc-clock"; + #clock-cells = <1>; + reg = <0x02006500 4>; /* SOC_GPIO_CONTROL0 */ + clocks = <&xtal1>, <&xtal3>; + clock-output-names = "xtal1_div", "32khz"; + }; -- 2.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
