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Diffstat (limited to 'Documentation/devicetree/bindings/soc/sunxi/sram.txt')
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diff --git a/Documentation/devicetree/bindings/soc/sunxi/sram.txt b/Documentation/devicetree/bindings/soc/sunxi/sram.txt new file mode 100644 index 000000000000..067698112f5f --- /dev/null +++ b/Documentation/devicetree/bindings/soc/sunxi/sram.txt | |||
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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 | ||
19 | Documentation/devicetree/bindings/misc/sram.txt | ||
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 | }; | ||