| Thomas Abraham | cd1b00e | 2012-08-23 17:10:09 +0000 | [diff] [blame^] | 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 | [B] If core card-detect bindings and "samsung,cd-pinmux-gpio" property |
| 16 | is not specified, it is assumed that there is no card detection |
| 17 | mechanism used. |
| 18 | |
| 19 | Required SoC Specific Properties: |
| 20 | - compatible: should be one of the following |
| 21 | - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci |
| 22 | controller. |
| 23 | - "samsung,exynos4210-sdhci": For controllers compatible with Exynos4 sdhci |
| 24 | controller. |
| 25 | |
| 26 | Required Board Specific Properties: |
| 27 | - gpios: Should specify the gpios used for clock, command and data lines. The |
| 28 | gpio specifier format depends on the gpio controller. |
| 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. |
| 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 | gpios = <&gpk2 0 2 0 3>, /* clock line */ |
| 44 | <&gpk2 1 2 0 3>, /* command line */ |
| 45 | <&gpk2 3 2 3 3>, /* data line 0 */ |
| 46 | <&gpk2 4 2 3 3>, /* data line 1 */ |
| 47 | <&gpk2 5 2 3 3>, /* data line 2 */ |
| 48 | <&gpk2 6 2 3 3>; /* data line 3 */ |
| 49 | }; |
| 50 | |
| 51 | Note: This example shows both SoC specific and board specific properties |
| 52 | in a single device node. The properties can be actually be seperated |
| 53 | into SoC specific node and board specific node. |