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Documentation / devicetree / bindings / mmc / samsung-sdhci.txt




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Based on kernel version 3.9. Page generated on 2013-05-02 22:59 EST.

1	* Samsung's SDHCI Controller device tree bindings
2	
3	Samsung's SDHCI controller is used as a connectivity interface with external
4	MMC, SD and eMMC storage mediums. This file documents differences between the
5	core mmc properties described by mmc.txt and the properties used by the
6	Samsung implmentation of the SDHCI controller.
7	
8	Note: The mmc core bindings documentation states that if none of the core
9	card-detect bindings are used, then the standard sdhci card detect mechanism
10	is used. The Samsung's SDHCI controller bindings extends this as listed below.
11	
12	[A] The property "samsung,cd-pinmux-gpio" can be used as stated in the
13	    "Optional Board Specific Properties" section below.
14	
15	Required SoC Specific Properties:
16	- compatible: should be one of the following
17	  - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci
18	    controller.
19	  - "samsung,exynos4210-sdhci": For controllers compatible with Exynos4 sdhci
20	    controller.
21	
22	Required Board Specific Properties:
23	- Samsung GPIO variant (will be completely replaced by pinctrl):
24	  - gpios: Should specify the gpios used for clock, command and data lines. The
25	    gpio specifier format depends on the gpio controller.
26	- Pinctrl variant (preferred if available):
27	  - pinctrl-0: Should specify pin control groups used for this controller.
28	  - pinctrl-names: Should contain only one value - "default".
29	
30	Optional Board Specific Properties:
31	- samsung,cd-pinmux-gpio: Specifies the card detect line that is routed
32	  through a pinmux to the card-detect pin of the card slot. This property
33	  should be used only if none of the mmc core card-detect properties are
34	  used. Only for Samsung GPIO variant.
35	
36	Example:
37		sdhci@12530000 {
38			compatible = "samsung,exynos4210-sdhci";
39			reg = <0x12530000 0x100>;
40			interrupts = <0 75 0>;
41			bus-width = <4>;
42			cd-gpios = <&gpk2 2 2 3 3>;
43	
44			/* Samsung GPIO variant */
45			gpios = <&gpk2 0 2 0 3>,  /* clock line */
46				<&gpk2 1 2 0 3>,  /* command line */
47				<&gpk2 3 2 3 3>,  /* data line 0 */
48				<&gpk2 4 2 3 3>,  /* data line 1 */
49				<&gpk2 5 2 3 3>,  /* data line 2 */
50				<&gpk2 6 2 3 3>;  /* data line 3 */
51	
52			/* Pinctrl variant */
53			pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus4>;
54			pinctrl-names = "default";
55		};
56	
57		Note: This example shows both SoC specific and board specific properties
58		in a single device node. The properties can be actually be separated
59		into SoC specific node and board specific node.
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