xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/c6x/emifa.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunExternal Memory Interface
2*4882a593Smuzhiyun-------------------------
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunThe emifa node describes a simple external bus controller found on some C6X
5*4882a593SmuzhiyunSoCs. This interface provides external busses with a number of chip selects.
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunRequired properties:
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun- compatible: must be "ti,c64x+emifa", "simple-bus"
10*4882a593Smuzhiyun- reg: register area base and size
11*4882a593Smuzhiyun- #address-cells: must be 2 (chip-select + offset)
12*4882a593Smuzhiyun- #size-cells: must be 1
13*4882a593Smuzhiyun- ranges: mapping from EMIFA space to parent space
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunOptional properties:
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun- ti,dscr-dev-enable: Device ID if EMIF is enabled/disabled from DSCR
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun- ti,emifa-burst-priority:
21*4882a593Smuzhiyun      Number of memory transfers after which the EMIF will elevate the priority
22*4882a593Smuzhiyun      of the oldest command in the command FIFO. Setting this field to 255
23*4882a593Smuzhiyun      disables this feature, thereby allowing old commands to stay in the FIFO
24*4882a593Smuzhiyun      indefinitely.
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun- ti,emifa-ce-config:
27*4882a593Smuzhiyun      Configuration values for each of the supported chip selects.
28*4882a593Smuzhiyun
29*4882a593SmuzhiyunExample:
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun	emifa@70000000 {
32*4882a593Smuzhiyun		compatible = "ti,c64x+emifa", "simple-bus";
33*4882a593Smuzhiyun		#address-cells = <2>;
34*4882a593Smuzhiyun		#size-cells = <1>;
35*4882a593Smuzhiyun		reg = <0x70000000 0x100>;
36*4882a593Smuzhiyun		ranges = <0x2 0x0 0xa0000000 0x00000008
37*4882a593Smuzhiyun		          0x3 0x0 0xb0000000 0x00400000
38*4882a593Smuzhiyun			  0x4 0x0 0xc0000000 0x10000000
39*4882a593Smuzhiyun			  0x5 0x0 0xD0000000 0x10000000>;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun		ti,dscr-dev-enable = <13>;
42*4882a593Smuzhiyun		ti,emifa-burst-priority = <255>;
43*4882a593Smuzhiyun		ti,emifa-ce-config = <0x00240120
44*4882a593Smuzhiyun				      0x00240120
45*4882a593Smuzhiyun				      0x00240122
46*4882a593Smuzhiyun				      0x00240122>;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun		flash@3,0 {
49*4882a593Smuzhiyun			#address-cells = <1>;
50*4882a593Smuzhiyun			#size-cells = <1>;
51*4882a593Smuzhiyun			compatible = "cfi-flash";
52*4882a593Smuzhiyun			reg = <0x3 0x0 0x400000>;
53*4882a593Smuzhiyun			bank-width = <1>;
54*4882a593Smuzhiyun			device-width = <1>;
55*4882a593Smuzhiyun			partition@0 {
56*4882a593Smuzhiyun				reg = <0x0 0x400000>;
57*4882a593Smuzhiyun				label = "NOR";
58*4882a593Smuzhiyun			};
59*4882a593Smuzhiyun		};
60*4882a593Smuzhiyun	};
61*4882a593Smuzhiyun
62*4882a593SmuzhiyunThis shows a flash chip attached to chip select 3.
63