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- * Exynos DWC_mobile_storage
- The Exynos provides DWC_mobile_storage interface which supports
- . Embedded Multimedia Cards (EMMC-version 4.5)
- . Secure Digital memory (SD mem-version 2.0)
- . Secure Digital I/O (SDIO-version 3.0)
- . Consumer Electronics Advanced Transport Architecture (CE-ATA-version 1.1)
- The Exynos DWC_mobile_storage provides four channels.
- SOC specific and Board specific properties are channel specific.
- Required SoC Specific Properties:
- - compatible: should be
- - samsung,exynos-dwmmc: for exynos platforms
- - reg: physical base address of the controller and length of memory mapped
- region.
- - interrupts: The interrupt number to the cpu.
- Required Board Specific Properties:
- - #address-cells: should be 1.
- - #size-cells: should be 0.
- - samsung,bus-width: The width of the bus used to interface the devices
- supported by DWC_mobile_storage (SD-MMC/EMMC/SDIO).
- . Typically the bus width is 4 or 8.
- - samsung,timing: The timing values to be written into the
- Drv/sample clock selection register of corresponding channel.
- . It is comprised of 3 values corresponding to the 3 fileds
- 'SelClk_sample', 'SelClk_drv' and 'DIVRATIO' of CLKSEL register.
- . SelClk_sample: Select sample clock among 8 shifted clocks.
- . SelClk_drv: Select drv clock among 8 shifted clocks.
- . DIVRATIO: Clock Divide ratio select.
- . The above 3 values are used by the clock phase shifter.
- Example:
- mmc@12200000 {
- samsung,bus-width = <8>;
- samsung,timing = <1 3 3>;
- samsung,removable = <1>;
- }
- In the above example,
- . The bus width is 8
- . Timing is comprised of 3 values as explained below
- 1 - SelClk_sample
- 3 - SelClk_drv
- 3 - DIVRATIO
- . The 'removable' flag indicates whether the the particilar device
- cannot be removed (always present) or it is a removable device.
- 1 - Indicates that the device is removable.
- 0 - Indicates that the device cannot be removed.
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