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Documentation / devicetree / bindings / arm / vexpress-sysreg.txt




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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:00 EST.

1	ARM Versatile Express system registers
2	--------------------------------------
3	
4	This is a system control registers block, providing multiple low level
5	platform functions like board detection and identification, software
6	interrupt generation, MMC and NOR Flash control etc.
7	
8	Required node properties:
9	- compatible value : = "arm,vexpress,sysreg";
10	- reg : physical base address and the size of the registers window
11	- gpio-controller : specifies that the node is a GPIO controller
12	- #gpio-cells : size of the GPIO specifier, should be 2:
13	  - first cell is the pseudo-GPIO line number:
14	    0 - MMC CARDIN
15	    1 - MMC WPROT
16	    2 - NOR FLASH WPn
17	  - second cell can take standard GPIO flags (currently ignored).
18	
19	Example:
20		v2m_sysreg: sysreg@10000000 {
21	 		compatible = "arm,vexpress-sysreg";
22	 		reg = <0x10000000 0x1000>;
23			gpio-controller;
24			#gpio-cells = <2>;
25	 	};
26	
27	This block also can also act a bridge to the platform's configuration
28	bus via "system control" interface, addressing devices with site number,
29	position in the board stack, config controller, function and device
30	numbers - see motherboard's TRM for more details.
31	
32	The node describing a config device must refer to the sysreg node via
33	"arm,vexpress,config-bridge" phandle (can be also defined in the node's
34	parent) and relies on the board topology properties - see main vexpress
35	node documentation for more details. It must also define the following
36	property:
37	- arm,vexpress-sysreg,func : must contain two cells:
38	  - first cell defines function number (eg. 1 for clock generator,
39	    2 for voltage regulators etc.)
40	  - device number (eg. osc 0, osc 1 etc.)
41	
42	Example:
43		mcc {
44			arm,vexpress,config-bridge = <&v2m_sysreg>;
45	
46			osc@0 {
47				compatible = "arm,vexpress-osc";
48				arm,vexpress-sysreg,func = <1 0>;
49			};
50		};
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