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Commit 4d735e54 authored by Boris Brezillon's avatar Boris Brezillon Committed by Nicolas Ferre
Browse files

clk: at91: add slow clk documentation 



Add slow clk, and slow oscillators documentation.

Signed-off-by: default avatarBoris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: default avatarMike Turquette <mturquette@linaro.org>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
parent 80eded6c

Documentation/devicetree/bindings/clock/at91-clock.txt

+72 −0
Original line number Diff line number Diff line
@@ -6,6 +6,16 @@ This binding uses the common clock binding[1]. 


Required properties:

- compatible : shall be one of the following:

	"atmel,at91sam9x5-sckc":

		at91 SCKC (Slow Clock Controller)

		This node contains the slow clock definitions.



	"atmel,at91sam9x5-clk-slow-osc":

		at91 slow oscillator



	"atmel,at91sam9x5-clk-slow-rc-osc":

		at91 internal slow RC oscillator



	"atmel,at91rm9200-pmc" or

	"atmel,at91sam9g45-pmc" or

	"atmel,at91sam9n12-pmc" or
@@ -15,6 +25,11 @@ Required properties: 
		All at91 specific clocks (clocks defined below) must be child

		node of the PMC node.



	"atmel,at91sam9x5-clk-slow" (under sckc node)

	or

	"atmel,at91sam9260-clk-slow" (under pmc node):

		at91 slow clk



	"atmel,at91rm9200-clk-main-osc"

	"atmel,at91sam9x5-clk-main-rc-osc"

		at91 main clk sources
@@ -59,6 +74,63 @@ Required properties: 
	"atmel,at91sam9x5-clk-utmi":

		at91 utmi clock



Required properties for SCKC node:

- reg : defines the IO memory reserved for the SCKC.

- #size-cells : shall be 0 (reg is used to encode clk id).

- #address-cells : shall be 1 (reg is used to encode clk id).





For example:

	sckc: sckc@fffffe50 {

		compatible = "atmel,sama5d3-pmc";

		reg = <0xfffffe50 0x4>

		#size-cells = <0>;

		#address-cells = <1>;



		/* put at91 slow clocks here */

	};





Required properties for internal slow RC oscillator:

- #clock-cells : from common clock binding; shall be set to 0.

- clock-frequency : define the internal RC oscillator frequency.



Optional properties:

- clock-accuracy : define the internal RC oscillator accuracy.



For example:

	slow_rc_osc: slow_rc_osc {

		compatible = "atmel,at91sam9x5-clk-slow-rc-osc";

		clock-frequency = <32768>;

		clock-accuracy = <50000000>;

	};



Required properties for slow oscillator:

- #clock-cells : from common clock binding; shall be set to 0.

- clocks : shall encode the main osc source clk sources (see atmel datasheet).



Optional properties:

- atmel,osc-bypass : boolean property. Set this when a clock signal is directly

  provided on XIN.



For example:

	slow_osc: slow_osc {

		compatible = "atmel,at91rm9200-clk-slow-osc";

		#clock-cells = <0>;

		clocks = <&slow_xtal>;

	};



Required properties for slow clock:

- #clock-cells : from common clock binding; shall be set to 0.

- clocks : shall encode the slow clk sources (see atmel datasheet).



For example:

	clk32k: slck {

		compatible = "atmel,at91sam9x5-clk-slow";

		#clock-cells = <0>;

		clocks = <&slow_rc_osc &slow_osc>;

	};



Required properties for PMC node:

- reg : defines the IO memory reserved for the PMC.

- #size-cells : shall be 0 (reg is used to encode clk id).