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Jaehoon Chung7d3ca0f2014-05-16 13:59:51 +09001* Exynos DWC_mobile_storage
Amar07eb5f92013-04-27 11:42:53 +05302
Jaehoon Chung7d3ca0f2014-05-16 13:59:51 +09003The Exynos provides DWC_mobile_storage interface which supports
Amar07eb5f92013-04-27 11:42:53 +05304. Embedded Multimedia Cards (EMMC-version 4.5)
5. Secure Digital memory (SD mem-version 2.0)
6. Secure Digital I/O (SDIO-version 3.0)
7. Consumer Electronics Advanced Transport Architecture (CE-ATA-version 1.1)
8
Jaehoon Chung7d3ca0f2014-05-16 13:59:51 +09009The Exynos DWC_mobile_storage provides four channels.
Amar07eb5f92013-04-27 11:42:53 +053010SOC specific and Board specific properties are channel specific.
11
12Required SoC Specific Properties:
13
14- compatible: should be
Jaehoon Chung7d3ca0f2014-05-16 13:59:51 +090015 - samsung,exynos-dwmmc: for exynos platforms
Amar07eb5f92013-04-27 11:42:53 +053016
17- reg: physical base address of the controller and length of memory mapped
18 region.
19
20- interrupts: The interrupt number to the cpu.
21
22Required Board Specific Properties:
23
24- #address-cells: should be 1.
25- #size-cells: should be 0.
26- samsung,bus-width: The width of the bus used to interface the devices
27 supported by DWC_mobile_storage (SD-MMC/EMMC/SDIO).
28 . Typically the bus width is 4 or 8.
29- samsung,timing: The timing values to be written into the
30 Drv/sample clock selection register of corresponding channel.
31 . It is comprised of 3 values corresponding to the 3 fileds
32 'SelClk_sample', 'SelClk_drv' and 'DIVRATIO' of CLKSEL register.
33 . SelClk_sample: Select sample clock among 8 shifted clocks.
34 . SelClk_drv: Select drv clock among 8 shifted clocks.
35 . DIVRATIO: Clock Divide ratio select.
36 . The above 3 values are used by the clock phase shifter.
37
38Example:
39
40mmc@12200000 {
41 samsung,bus-width = <8>;
42 samsung,timing = <1 3 3>;
43 samsung,removable = <1>;
44}
45In the above example,
46 . The bus width is 8
47 . Timing is comprised of 3 values as explained below
48 1 - SelClk_sample
49 3 - SelClk_drv
50 3 - DIVRATIO
51 . The 'removable' flag indicates whether the the particilar device
52 cannot be removed (always present) or it is a removable device.
53 1 - Indicates that the device is removable.
54 0 - Indicates that the device cannot be removed.