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Documentation / devicetree / bindings / mmc / synopsis-dw-mshc.txt




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Based on kernel version 3.11. Page generated on 2013-09-03 22:51 EST.

1	* Synopsis Designware Mobile Storage Host Controller
2	
3	The Synopsis 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 Synopsis Designware Mobile Storage Host Controller.
7	
8	Required Properties:
9	
10	* compatible: should be
11		- snps,dw-mshc: for controllers compliant with synopsis 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		};
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