[deliverable/linux.git] / Documentation / devicetree / bindings / sram / sunxi-sram.txt

Allwinnner SoC SRAM controllers
-----------------------------------------------------

The SRAM controller found on most Allwinner devices is represented by
a regular node for the SRAM controller itself, with sub-nodes
reprensenting the SRAM handled by the SRAM controller.

Controller Node
---------------

Required properties:
- compatible : "allwinner,sun4i-a10-sram-controller"
- reg : sram controller register offset + length

SRAM nodes
----------

Each SRAM is described using the mmio-sram bindings documented in
Documentation/devicetree/bindings/sram/sram.txt

Each SRAM will have SRAM sections that are going to be handled by the
SRAM controller as subnodes. These sections are represented following
once again the representation described in the mmio-sram binding.

The valid sections compatible are:
    - allwinner,sun4i-a10-sram-a3-a4
    - allwinner,sun4i-a10-sram-d

Devices using SRAM sections
---------------------------

Some devices need to request to the SRAM controller to map an SRAM for
their exclusive use.

The relationship between such a device and an SRAM section is
expressed through the allwinner,sram property, that will take a
phandle and an argument.

This valid values for this argument are:
  - 0: CPU
  - 1: Device

Example
-------
sram-controller@01c00000 {
	compatible = "allwinner,sun4i-a10-sram-controller";
	reg = <0x01c00000 0x30>;
	#address-cells = <1>;
	#size-cells = <1>;
	ranges;

	sram_a: sram@00000000 {
		compatible = "mmio-sram";
		reg = <0x00000000 0xc000>;
		#address-cells = <1>;
		#size-cells = <1>;
		ranges = <0 0x00000000 0xc000>;

		emac_sram: sram-section@8000 {
			compatible = "allwinner,sun4i-a10-sram-a3-a4";
			reg = <0x8000 0x4000>;
			status = "disabled";
		};
	};
};

emac: ethernet@01c0b000 {
	compatible = "allwinner,sun4i-a10-emac";
	...

	allwinner,sram = <&emac_sram 1>;
};
Commit	Line	Data
4af34b57 MR	1	Allwinnner SoC SRAM controllers
	2	-----------------------------------------------------
	3
	4	The SRAM controller found on most Allwinner devices is represented by
	5	a regular node for the SRAM controller itself, with sub-nodes
	6	reprensenting the SRAM handled by the SRAM controller.
	7
	8	Controller Node
	9	---------------
	10
	11	Required properties:
	12	- compatible : "allwinner,sun4i-a10-sram-controller"
	13	- reg : sram controller register offset + length
	14
	15	SRAM nodes
	16	----------
	17
	18	Each SRAM is described using the mmio-sram bindings documented in
22697acd	19	Documentation/devicetree/bindings/sram/sram.txt
4af34b57 MR	20
	21	Each SRAM will have SRAM sections that are going to be handled by the
	22	SRAM controller as subnodes. These sections are represented following
	23	once again the representation described in the mmio-sram binding.
	24
	25	The valid sections compatible are:
	26	- allwinner,sun4i-a10-sram-a3-a4
	27	- allwinner,sun4i-a10-sram-d
	28
	29	Devices using SRAM sections
	30	---------------------------
	31
	32	Some devices need to request to the SRAM controller to map an SRAM for
	33	their exclusive use.
	34
	35	The relationship between such a device and an SRAM section is
	36	expressed through the allwinner,sram property, that will take a
	37	phandle and an argument.
	38
	39	This valid values for this argument are:
	40	- 0: CPU
	41	- 1: Device
	42
	43	Example
	44	-------
	45	sram-controller@01c00000 {
	46	compatible = "allwinner,sun4i-a10-sram-controller";
	47	reg = <0x01c00000 0x30>;
	48	#address-cells = <1>;
	49	#size-cells = <1>;
	50	ranges;
	51
	52	sram_a: sram@00000000 {
	53	compatible = "mmio-sram";
	54	reg = <0x00000000 0xc000>;
	55	#address-cells = <1>;
	56	#size-cells = <1>;
	57	ranges = <0 0x00000000 0xc000>;
	58
	59	emac_sram: sram-section@8000 {
	60	compatible = "allwinner,sun4i-a10-sram-a3-a4";
	61	reg = <0x8000 0x4000>;
	62	status = "disabled";
	63	};
	64	};
	65	};
	66
	67	emac: ethernet@01c0b000 {
	68	compatible = "allwinner,sun4i-a10-emac";
	69	...
	70
	71	allwinner,sram = <&emac_sram 1>;
	72	};