| * Samsung Exynos specific extensions to the Synopsys Designware Mobile |
| Storage Host Controller |
| |
| The Synopsys 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 Synopsys dw mshc controller properties described |
| by synopsys-dw-mshc.txt and the properties used by the Samsung Exynos specific |
| extensions to the Synopsys Designware Mobile Storage Host Controller. |
| |
| Required Properties: |
| |
| * compatible: should be |
| - "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210 |
| specific extensions. |
| - "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412 |
| specific extensions. |
| - "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250 |
| specific extensions. |
| - "samsung,exynos5420-dw-mshc": for controllers with Samsung Exynos5420 |
| specific extensions. |
| - "samsung,exynos7-dw-mshc": for controllers with Samsung Exynos7 |
| specific extensions. |
| - "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7 |
| specific extensions having an SMU. |
| |
| * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface |
| unit (ciu) clock. This property is applicable only for Exynos5 SoC's and |
| ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7. |
| |
| * samsung,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value |
| in transmit mode and CIU clock phase shift value in receive mode for single |
| data rate mode operation. Refer notes below for the order of the cells and the |
| valid values. |
| |
| * samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock phase shift value |
| in transmit mode and CIU clock phase shift value in receive mode for double |
| data rate mode operation. Refer notes below for the order of the cells and the |
| valid values. |
| |
| Notes for the sdr-timing and ddr-timing values: |
| |
| The order of the cells should be |
| - First Cell: CIU clock phase shift value for tx mode. |
| - Second Cell: CIU clock phase shift value for rx mode. |
| |
| Valid values for SDR and DDR CIU clock timing for Exynos5250: |
| - valid value for tx phase shift and rx phase shift is 0 to 7. |
| - when CIU clock divider value is set to 3, all possible 8 phase shift |
| values can be used. |
| - if CIU clock divider value is 0 (that is divide by 1), both tx and rx |
| phase shift clocks should be 0. |
| |
| Required properties for a slot (Deprecated - Recommend to use one slot per host): |
| |
| * gpios: specifies a list of gpios used for command, clock and data bus. The |
| first gpio is the command line and the second gpio is the clock line. The |
| rest of the gpios (depending on the bus-width property) are the data lines in |
| no particular order. The format of the gpio specifier depends on the gpio |
| controller. |
| (Deprecated - Refer to Documentation/devicetree/binding/pinctrl/samsung-pinctrl.txt) |
| |
| Example: |
| |
| The MSHC controller node can be split into two portions, SoC specific and |
| board specific portions as listed below. |
| |
| dwmmc0@12200000 { |
| compatible = "samsung,exynos5250-dw-mshc"; |
| reg = <0x12200000 0x1000>; |
| interrupts = <0 75 0>; |
| #address-cells = <1>; |
| #size-cells = <0>; |
| }; |
| |
| dwmmc0@12200000 { |
| num-slots = <1>; |
| cap-mmc-highspeed; |
| cap-sd-highspeed; |
| broken-cd; |
| fifo-depth = <0x80>; |
| card-detect-delay = <200>; |
| samsung,dw-mshc-ciu-div = <3>; |
| samsung,dw-mshc-sdr-timing = <2 3>; |
| samsung,dw-mshc-ddr-timing = <1 2>; |
| bus-width = <8>; |
| }; |