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diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt new file mode 100644 index 00000000..3b3a1ee0 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt @@ -0,0 +1,59 @@ +* Samsung's SDHCI Controller device tree bindings + +Samsung's SDHCI controller is used as a connectivity interface with external +MMC, SD and eMMC storage mediums. This file documents differences between the +core mmc properties described by mmc.txt and the properties used by the +Samsung implmentation of the SDHCI controller. + +Note: The mmc core bindings documentation states that if none of the core +card-detect bindings are used, then the standard sdhci card detect mechanism +is used. The Samsung's SDHCI controller bindings extends this as listed below. + +[A] The property "samsung,cd-pinmux-gpio" can be used as stated in the + "Optional Board Specific Properties" section below. + +Required SoC Specific Properties: +- compatible: should be one of the following + - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci + controller. + - "samsung,exynos4210-sdhci": For controllers compatible with Exynos4 sdhci + controller. + +Required Board Specific Properties: +- Samsung GPIO variant (will be completely replaced by pinctrl): + - gpios: Should specify the gpios used for clock, command and data lines. The + gpio specifier format depends on the gpio controller. +- Pinctrl variant (preferred if available): + - pinctrl-0: Should specify pin control groups used for this controller. + - pinctrl-names: Should contain only one value - "default". + +Optional Board Specific Properties: +- samsung,cd-pinmux-gpio: Specifies the card detect line that is routed + through a pinmux to the card-detect pin of the card slot. This property + should be used only if none of the mmc core card-detect properties are + used. Only for Samsung GPIO variant. + +Example: + sdhci@12530000 { + compatible = "samsung,exynos4210-sdhci"; + reg = <0x12530000 0x100>; + interrupts = <0 75 0>; + bus-width = <4>; + cd-gpios = <&gpk2 2 2 3 3>; + + /* Samsung GPIO variant */ + gpios = <&gpk2 0 2 0 3>, /* clock line */ + <&gpk2 1 2 0 3>, /* command line */ + <&gpk2 3 2 3 3>, /* data line 0 */ + <&gpk2 4 2 3 3>, /* data line 1 */ + <&gpk2 5 2 3 3>, /* data line 2 */ + <&gpk2 6 2 3 3>; /* data line 3 */ + + /* Pinctrl variant */ + pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus4>; + pinctrl-names = "default"; + }; + + Note: This example shows both SoC specific and board specific properties + in a single device node. The properties can be actually be separated + into SoC specific node and board specific node. |