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1 | * Synopsys Designware Mobile Storage Host Controller | ||
2 | |||
3 | The Synopsys designware mobile storage host controller is used to interface | ||
4 | a SoC with storage medium such as eMMC or SD/MMC cards. This file documents | ||
5 | differences between the core mmc properties described by mmc.txt and the | ||
6 | properties used by the Synopsys Designware Mobile Storage Host Controller. | ||
7 | |||
8 | Required 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 | |||
40 | Optional properties: | ||
41 | |||
42 | * clocks: from common clock binding: handle to biu and ciu clocks for the | ||
43 | bus interface unit clock and the card interface unit clock. | ||
44 | |||
45 | * clock-names: from common clock binding: Shall be "biu" and "ciu". | ||
46 | If the biu clock is missing we'll simply skip enabling it. If the | ||
47 | ciu clock is missing we'll just assume that the clock is running at | ||
48 | clock-frequency. It is an error to omit both the ciu clock and the | ||
49 | clock-frequency. | ||
50 | |||
51 | * clock-frequency: should be the frequency (in Hz) of the ciu clock. If this | ||
52 | is specified and the ciu clock is specified then we'll try to set the ciu | ||
53 | clock to this at probe time. | ||
54 | |||
55 | * num-slots: specifies the number of slots supported by the controller. | ||
56 | The number of physical slots actually used could be equal or less than the | ||
57 | value specified by num-slots. If this property is not specified, the value | ||
58 | of num-slot property is assumed to be 1. | ||
59 | |||
60 | * fifo-depth: The maximum size of the tx/rx fifo's. If this property is not | ||
61 | specified, the default value of the fifo size is determined from the | ||
62 | controller registers. | ||
63 | |||
64 | * card-detect-delay: Delay in milli-seconds before detecting card after card | ||
65 | insert event. The default value is 0. | ||
66 | |||
67 | * supports-highspeed: Enables support for high speed cards (up to 50MHz) | ||
68 | |||
69 | * broken-cd: as documented in mmc core bindings. | ||
70 | |||
71 | * vmmc-supply: The phandle to the regulator to use for vmmc. If this is | ||
72 | specified we'll defer probe until we can find this regulator. | ||
73 | |||
74 | Aliases: | ||
75 | |||
76 | - All the MSHC controller nodes should be represented in the aliases node using | ||
77 | the following format 'mshc{n}' where n is a unique number for the alias. | ||
78 | |||
79 | Example: | ||
80 | |||
81 | The MSHC controller node can be split into two portions, SoC specific and | ||
82 | board specific portions as listed below. | ||
83 | |||
84 | dwmmc0@12200000 { | ||
85 | compatible = "snps,dw-mshc"; | ||
86 | clocks = <&clock 351>, <&clock 132>; | ||
87 | clock-names = "biu", "ciu"; | ||
88 | reg = <0x12200000 0x1000>; | ||
89 | interrupts = <0 75 0>; | ||
90 | #address-cells = <1>; | ||
91 | #size-cells = <0>; | ||
92 | }; | ||
93 | |||
94 | dwmmc0@12200000 { | ||
95 | clock-frequency = <400000000>; | ||
96 | num-slots = <1>; | ||
97 | supports-highspeed; | ||
98 | broken-cd; | ||
99 | fifo-depth = <0x80>; | ||
100 | card-detect-delay = <200>; | ||
101 | vmmc-supply = <&buck8>; | ||
102 | |||
103 | slot@0 { | ||
104 | reg = <0>; | ||
105 | bus-width = <8>; | ||
106 | }; | ||
107 | }; | ||