| * 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,imx6ull-usdhc" |
| "fsl,imx7d-usdhc" |
| "fsl,imx7ulp-usdhc" |
| "fsl,imx8mq-usdhc" |
| "fsl,imx8mm-usdhc" |
| "fsl,imx8mn-usdhc" |
| "fsl,imx8qxp-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 */ |
| }; |
