xref: /freebsd/sys/contrib/device-tree/Bindings/mmc/exynos-dw-mshc.txt (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1* Samsung Exynos specific extensions to the Synopsys Designware Mobile
2  Storage Host Controller
3
4The Synopsys designware mobile storage host controller is used to interface
5a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
6differences between the core Synopsys dw mshc controller properties described
7by synopsys-dw-mshc.txt and the properties used by the Samsung Exynos specific
8extensions to the Synopsys Designware Mobile Storage Host Controller.
9
10Required Properties:
11
12* compatible: should be
13	- "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210
14	  specific extensions.
15	- "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412
16	  specific extensions.
17	- "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250
18	  specific extensions.
19	- "samsung,exynos5420-dw-mshc": for controllers with Samsung Exynos5420
20	  specific extensions.
21	- "samsung,exynos7-dw-mshc": for controllers with Samsung Exynos7
22	  specific extensions.
23	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
24	  specific extensions having an SMU.
25	- "axis,artpec8-dw-mshc": for controllers with ARTPEC-8 specific
26	  extensions.
27
28* samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
29  unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
30  ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7.
31
32* samsung,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
33  in transmit mode and CIU clock phase shift value in receive mode for single
34  data rate mode operation. Refer notes below for the order of the cells and the
35  valid values.
36
37* samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock phase shift value
38  in transmit mode and CIU clock phase shift value in receive mode for double
39  data rate mode operation. Refer notes below for the order of the cells and the
40  valid values.
41* samsung,dw-mshc-hs400-timing: Specifies the value of CIU TX and RX clock phase
42  shift value for hs400 mode operation.
43
44  Notes for the sdr-timing and ddr-timing values:
45
46    The order of the cells should be
47      - First Cell: CIU clock phase shift value for tx mode.
48      - Second Cell: CIU clock phase shift value for rx mode.
49
50    Valid values for SDR and DDR CIU clock timing for Exynos5250:
51      - valid value for tx phase shift and rx phase shift is 0 to 7.
52      - when CIU clock divider value is set to 3, all possible 8 phase shift
53        values can be used.
54      - if CIU clock divider value is 0 (that is divide by 1), both tx and rx
55        phase shift clocks should be 0.
56
57* samsung,read-strobe-delay: RCLK (Data strobe) delay to control HS400 mode
58  (Latency value for delay line in Read path)
59
60Required properties for a slot (Deprecated - Recommend to use one slot per host):
61
62* gpios: specifies a list of gpios used for command, clock and data bus. The
63  first gpio is the command line and the second gpio is the clock line. The
64  rest of the gpios (depending on the bus-width property) are the data lines in
65  no particular order. The format of the gpio specifier depends on the gpio
66  controller.
67(Deprecated - Refer to Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt)
68
69Example:
70
71  The MSHC controller node can be split into two portions, SoC specific and
72  board specific portions as listed below.
73
74	dwmmc0@12200000 {
75		compatible = "samsung,exynos5250-dw-mshc";
76		reg = <0x12200000 0x1000>;
77		interrupts = <0 75 0>;
78		#address-cells = <1>;
79		#size-cells = <0>;
80	};
81
82	dwmmc0@12200000 {
83		cap-mmc-highspeed;
84		cap-sd-highspeed;
85		broken-cd;
86		fifo-depth = <0x80>;
87		card-detect-delay = <200>;
88		samsung,dw-mshc-ciu-div = <3>;
89		samsung,dw-mshc-sdr-timing = <2 3>;
90		samsung,dw-mshc-ddr-timing = <1 2>;
91		samsung,dw-mshc-hs400-timing = <0 2>;
92		samsung,read-strobe-delay = <90>;
93		bus-width = <8>;
94	};
95