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1* Synopsys Designware Mobile Storage Host Controller
2
3The Synopsys designware mobile storage host controller is used to interface
4a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
5differences between the core mmc properties described by mmc.txt and the
6properties used by the Synopsys Designware Mobile Storage Host Controller.
7
8Required Properties:
9
10* compatible: should be
11 - snps,dw-mshc: for controllers compliant with synopsys dw-mshc.
12* #address-cells: should be 1.
13* #size-cells: should be 0.
14
15# Slots: The slot specific information are contained within child-nodes with
16 each child-node representing a supported slot. There should be atleast one
17 child node representing a card slot. The name of the child node representing
18 the slot is recommended to be slot@n where n is the unique number of the slot
19 connnected to the controller. The following are optional properties which
20 can be included in the slot child node.
21
22 * reg: specifies the physical slot number. The valid values of this
23 property is 0 to (num-slots -1), where num-slots is the value
24 specified by the num-slots property.
25
26 * bus-width: as documented in mmc core bindings.
27
28 * wp-gpios: specifies the write protect gpio line. The format of the
29 gpio specifier depends on the gpio controller. If a GPIO is not used
30 for write-protect, this property is optional.
31
32 * disable-wp: If the wp-gpios property isn't present then (by default)
33 we'd assume that the write protect is hooked up directly to the
34 controller's special purpose write protect line (accessible via
35 the WRTPRT register). However, it's possible that we simply don't
36 want write protect. In that case specify 'disable-wp'.
37 NOTE: This property is not required for slots known to always
38 connect to eMMC or SDIO cards.
39
40Optional properties:
41
42* resets: phandle + reset specifier pair, intended to represent hardware
43 reset signal present internally in some host controller IC designs.
44 See Documentation/devicetree/bindings/reset/reset.txt for details.
45
46* reset-names: request name for using "resets" property. Must be "reset".
47 (It will be used together with "resets" property.)
48
49* clocks: from common clock binding: handle to biu and ciu clocks for the
50 bus interface unit clock and the card interface unit clock.
51
52* clock-names: from common clock binding: Shall be "biu" and "ciu".
53 If the biu clock is missing we'll simply skip enabling it. If the
54 ciu clock is missing we'll just assume that the clock is running at
55 clock-frequency. It is an error to omit both the ciu clock and the
56 clock-frequency.
57
58* clock-frequency: should be the frequency (in Hz) of the ciu clock. If this
59 is specified and the ciu clock is specified then we'll try to set the ciu
60 clock to this at probe time.
61
62* clock-freq-min-max (DEPRECATED): Minimum and Maximum clock frequency for card output
63 clock(cclk_out). If it's not specified, max is 200MHZ and min is 400KHz by default.
64 (Use the "max-frequency" instead of "clock-freq-min-max".)
65
66* num-slots: specifies the number of slots supported by the controller.
67 The number of physical slots actually used could be equal or less than the
68 value specified by num-slots. If this property is not specified, the value
69 of num-slot property is assumed to be 1.
70
71* fifo-depth: The maximum size of the tx/rx fifo's. If this property is not
72 specified, the default value of the fifo size is determined from the
73 controller registers.
74
75* card-detect-delay: Delay in milli-seconds before detecting card after card
76 insert event. The default value is 0.
77
78* vmmc-supply: The phandle to the regulator to use for vmmc. If this is
79 specified we'll defer probe until we can find this regulator.
80
81* dmas: List of DMA specifiers with the controller specific format as described
82 in the generic DMA client binding. Refer to dma.txt for details.
83
84* dma-names: request names for generic DMA client binding. Must be "rx-tx".
85 Refer to dma.txt for details.
86
87Aliases:
88
89- All the MSHC controller nodes should be represented in the aliases node using
90 the following format 'mshc{n}' where n is a unique number for the alias.
91
92Example:
93
94The MSHC controller node can be split into two portions, SoC specific and
95board specific portions as listed below.
96
97 dwmmc0@12200000 {
98 compatible = "snps,dw-mshc";
99 clocks = <&clock 351>, <&clock 132>;
100 clock-names = "biu", "ciu";
101 reg = <0x12200000 0x1000>;
102 interrupts = <0 75 0>;
103 #address-cells = <1>;
104 #size-cells = <0>;
105 resets = <&rst 20>;
106 reset-names = "reset";
107 };
108
109[board specific internal DMA resources]
110
111 dwmmc0@12200000 {
112 clock-frequency = <400000000>;
113 clock-freq-min-max = <400000 200000000>;
114 num-slots = <1>;
115 broken-cd;
116 fifo-depth = <0x80>;
117 card-detect-delay = <200>;
118 vmmc-supply = <&buck8>;
119 bus-width = <8>;
120 cap-mmc-highspeed;
121 cap-sd-highspeed;
122 };
123
124[board specific generic DMA request binding]
125
126 dwmmc0@12200000 {
127 clock-frequency = <400000000>;
128 clock-freq-min-max = <400000 200000000>;
129 num-slots = <1>;
130 broken-cd;
131 fifo-depth = <0x80>;
132 card-detect-delay = <200>;
133 vmmc-supply = <&buck8>;
134 bus-width = <8>;
135 cap-mmc-highspeed;
136 cap-sd-highspeed;
137 dmas = <&pdma 12>;
138 dma-names = "rx-tx";
139 };