| * Synopsis Designware Mobile Storage Host Controller |
| |
| The Synopsis designware mobile storage host controller is used to interface |
| a SoC with storage medium such as eMMC or SD/MMC cards. This file documents |
| differences between the core mmc properties described by mmc.txt and the |
| properties used by the Synopsis Designware Mobile Storage Host Controller. |
| |
| Required Properties: |
| |
| * compatible: should be |
| - snps,dw-mshc: for controllers compliant with synopsis dw-mshc. |
| * #address-cells: should be 1. |
| * #size-cells: should be 0. |
| |
| # Slots: The slot specific information are contained within child-nodes with |
| each child-node representing a supported slot. There should be atleast one |
| child node representing a card slot. The name of the child node representing |
| the slot is recommended to be slot@n where n is the unique number of the slot |
| connnected to the controller. The following are optional properties which |
| can be included in the slot child node. |
| |
| * reg: specifies the physical slot number. The valid values of this |
| property is 0 to (num-slots -1), where num-slots is the value |
| specified by the num-slots property. |
| |
| * bus-width: as documented in mmc core bindings. |
| |
| * wp-gpios: specifies the write protect gpio line. The format of the |
| gpio specifier depends on the gpio controller. If a GPIO is not used |
| for write-protect, this property is optional. |
| |
| * disable-wp: If the wp-gpios property isn't present then (by default) |
| we'd assume that the write protect is hooked up directly to the |
| controller's special purpose write protect line (accessible via |
| the WRTPRT register). However, it's possible that we simply don't |
| want write protect. In that case specify 'disable-wp'. |
| NOTE: This property is not required for slots known to always |
| connect to eMMC or SDIO cards. |
| |
| Optional properties: |
| |
| * num-slots: specifies the number of slots supported by the controller. |
| The number of physical slots actually used could be equal or less than the |
| value specified by num-slots. If this property is not specified, the value |
| of num-slot property is assumed to be 1. |
| |
| * fifo-depth: The maximum size of the tx/rx fifo's. If this property is not |
| specified, the default value of the fifo size is determined from the |
| controller registers. |
| |
| * card-detect-delay: Delay in milli-seconds before detecting card after card |
| insert event. The default value is 0. |
| |
| * supports-highspeed: Enables support for high speed cards (upto 50MHz) |
| |
| * broken-cd: as documented in mmc core bindings. |
| |
| Aliases: |
| |
| - All the MSHC controller nodes should be represented in the aliases node using |
| the following format 'mshc{n}' where n is a unique number for the alias. |
| |
| Example: |
| |
| The MSHC controller node can be split into two portions, SoC specific and |
| board specific portions as listed below. |
| |
| dwmmc0@12200000 { |
| compatible = "snps,dw-mshc"; |
| reg = <0x12200000 0x1000>; |
| interrupts = <0 75 0>; |
| #address-cells = <1>; |
| #size-cells = <0>; |
| }; |
| |
| dwmmc0@12200000 { |
| num-slots = <1>; |
| supports-highspeed; |
| broken-cd; |
| fifo-depth = <0x80>; |
| card-detect-delay = <200>; |
| |
| slot@0 { |
| reg = <0>; |
| bus-width = <8>; |
| }; |
| }; |