diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt new file mode 100644 index 000000000..3e29050ec --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt @@ -0,0 +1,54 @@ +* Freescale Enhanced Secure Digital Host Controller (eSDHC) for i.MX + +The Enhanced Secure Digital Host Controller on Freescale i.MX family +provides an interface for MMC, SD, and SDIO types of memory cards. + +This file documents differences between the core properties described +by mmc.txt and the properties used by the sdhci-esdhc-imx driver. + +Required properties: +- compatible : Should be "fsl,<chip>-esdhc", the supported chips include + "fsl,imx25-esdhc" + "fsl,imx35-esdhc" + "fsl,imx51-esdhc" + "fsl,imx53-esdhc" + "fsl,imx6q-usdhc" + "fsl,imx6sl-usdhc" + "fsl,imx6sx-usdhc" + "fsl,imx7d-usdhc" + +Optional properties: +- fsl,wp-controller : Indicate to use controller internal write protection +- fsl,delay-line : Specify the number of delay cells for override mode. + This is used to set the clock delay for DLL(Delay Line) on override mode + to select a proper data sampling window in case the clock quality is not good + due to signal path is too long on the board. Please refer to eSDHC/uSDHC + chapter, DLL (Delay Line) section in RM for details. +- voltage-ranges : Specify the voltage range in case there are software + transparent level shifters on the outputs of the controller. Two cells are + required, first cell specifies minimum slot voltage (mV), second cell + specifies maximum slot voltage (mV). Several ranges could be specified. +- fsl,tuning-start-tap: Specify the start dealy cell point when send first CMD19 + in tuning procedure. +- fsl,tuning-step: Specify the increasing delay cell steps in tuning procedure. + The uSDHC use one delay cell as default increasing step to do tuning process. + This property allows user to change the tuning step to more than one delay + cells which is useful for some special boards or cards when the default + tuning step can't find the proper delay window within limited tuning retries. + +Examples: + +esdhc@70004000 { + compatible = "fsl,imx51-esdhc"; + reg = <0x70004000 0x4000>; + interrupts = <1>; + fsl,wp-controller; +}; + +esdhc@70008000 { + compatible = "fsl,imx51-esdhc"; + reg = <0x70008000 0x4000>; + interrupts = <2>; + cd-gpios = <&gpio1 6 0>; /* GPIO1_6 */ + wp-gpios = <&gpio1 5 0>; /* GPIO1_5 */ +}; |