xref: /freebsd-11.0-release/sys/boot/fdt/dts/bindings-localbus.txt

$FreeBSD: releng/11.0/sys/boot/fdt/dts/bindings-localbus.txt 235609 2012-05-18 14:41:14Z gber $

Marvell Device bus (localbus) configuration.
============================================

1. Properties for localbus nodes

1.1 ranges

Property:	ranges

Value type:	<prop-encoded-array> encoded as arbitrary number of localbus 
		nodes specifiers.
		
Description:	ranges property defines values used for mapping devices 
		connected to localbus, in Marvell devices it is used also for 
		setting decoding windows. 
		
		a) child node address-cells:
		   - first cell: number of bank (chip select) 
		   - second cell: (Marvell devices) Target ID for decoding
		   	windows setup
		   	
		b) parent node address cells:
		   - address offset: used with parent's node base address to 
		   	specify base address of mapped device
		
		c) child node size-cells:
		   - size: defines amount of memory that should be reserved for
			device      
			
1.2 bank-count

Property:	bank-count

Value type:	<u32>	

Description:	The bank_count property defines maximum number of banks on
		localbus node. Bank is most often interpreted as device chip
		select, but may also describe another device (e.g. SPI flash).  
		
1.3 Example

	localbus@0 {
		#address-cells = <2>;
		#size-cells = <1>;
		compatible = "mrvl,lbc";
		bank-count = <5>;

		/* This reflects CPU decode windows setup. */
		ranges = <0x0 0x2f 0xb2200000 0x00100000
			  0x1 0x3e 0xb2100000 0x00100000
			  0x2 0x3d 0xb0000000 0x02000000
			  0x3 0x3b 0xb2000000 0x00100000>;
	};

2. Properties for localbus consumer nodes:

2.1 reg

Property:	reg

Value type: 	<prop-encoded-array>

Description:	A standard property required for localbus child nodes. Defines 
		the device memory region.
		
		a) first cell: number of bank (chip select)
		
		b) address offset: used with address offset from parent's ranges
			for corresponding bank to specify base address of 
			the device
		   	
		c) size: defines size of the device memory region
		
2.2 Example

	nor@0,0 {
		#address-cells = <1>;
		#size-cells = <1>;
		compatible = "cfi-flash";
		reg = <0x0 0x0 0x00100000>;
	};