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1Device tree bindings for i.MX Wireless External Interface Module (WEIM)
2
3The term "wireless" does not imply that the WEIM is literally an interface
4without wires. It simply means that this module was originally designed for
5wireless and mobile applications that use low-power technology.
6
7The actual devices are instantiated from the child nodes of a WEIM node.
8
9Required properties:
10
11 - compatible: Should contain one of the following:
12 "fsl,imx1-weim"
13 "fsl,imx27-weim"
14 "fsl,imx51-weim"
15 "fsl,imx50-weim"
16 "fsl,imx6q-weim"
17 - reg: A resource specifier for the register space
18 (see the example below)
19 - clocks: the clock, see the example below.
20 - #address-cells: Must be set to 2 to allow memory address translation
21 - #size-cells: Must be set to 1 to allow CS address passing
22 - ranges: Must be set up to reflect the memory layout with four
23 integer values for each chip-select line in use:
24
25 <cs-number> 0 <physical address of mapping> <size>
26
27Optional properties:
28
29 - fsl,weim-cs-gpr: For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
30 devices, it should be the phandle to the system General
31 Purpose Register controller that contains WEIM CS GPR
32 register, e.g. IOMUXC_GPR1 on i.MX6Q. IOMUXC_GPR1[11:0]
33 should be set up as one of the following 4 possible
34 values depending on the CS space configuration.
35
36 IOMUXC_GPR1[11:0] CS0 CS1 CS2 CS3
37 ---------------------------------------------
38 05 128M 0M 0M 0M
39 033 64M 64M 0M 0M
40 0113 64M 32M 32M 0M
41 01111 32M 32M 32M 32M
42
43 In case that the property is absent, the reset value or
44 what bootloader sets up in IOMUXC_GPR1[11:0] will be
45 used.
46
47 - fsl,burst-clk-enable For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
48 devices, the presence of this property indicates that
49 the weim bus should operate in Burst Clock Mode.
50
51Timing property for child nodes. It is mandatory, not optional.
52
53 - fsl,weim-cs-timing: The timing array, contains timing values for the
54 child node. We get the CS indexes from the address
55 ranges in the child node's "reg" property.
56 The number of registers depends on the selected chip:
57 For i.MX1, i.MX21 ("fsl,imx1-weim") there are two
58 registers: CSxU, CSxL.
59 For i.MX25, i.MX27, i.MX31 and i.MX35 ("fsl,imx27-weim")
60 there are three registers: CSCRxU, CSCRxL, CSCRxA.
61 For i.MX50, i.MX53 ("fsl,imx50-weim"),
62 i.MX51 ("fsl,imx51-weim") and i.MX6Q ("fsl,imx6q-weim")
63 there are six registers: CSxGCR1, CSxGCR2, CSxRCR1,
64 CSxRCR2, CSxWCR1, CSxWCR2.
65
66Example for an imx6q-sabreauto board, the NOR flash connected to the WEIM:
67
68 weim: weim@21b8000 {
69 compatible = "fsl,imx6q-weim";
70 reg = <0x021b8000 0x4000>;
71 clocks = <&clks 196>;
72 #address-cells = <2>;
73 #size-cells = <1>;
74 ranges = <0 0 0x08000000 0x08000000>;
75 fsl,weim-cs-gpr = <&gpr>;
76
77 nor@0,0 {
78 compatible = "cfi-flash";
79 reg = <0 0 0x02000000>;
80 #address-cells = <1>;
81 #size-cells = <1>;
82 bank-width = <2>;
83 fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
84 0x0000c000 0x1404a38e 0x00000000>;
85 };
86 };
87
88Example for an imx6q-based board, a multi-chipselect device connected to WEIM:
89
90In this case, both chip select 0 and 1 will be configured with the same timing
91array values.
92
93 weim: weim@21b8000 {
94 compatible = "fsl,imx6q-weim";
95 reg = <0x021b8000 0x4000>;
96 clocks = <&clks 196>;
97 #address-cells = <2>;
98 #size-cells = <1>;
99 ranges = <0 0 0x08000000 0x02000000
100 1 0 0x0a000000 0x02000000
101 2 0 0x0c000000 0x02000000
102 3 0 0x0e000000 0x02000000>;
103 fsl,weim-cs-gpr = <&gpr>;
104
105 acme@0 {
106 compatible = "acme,whatever";
107 reg = <0 0 0x100>, <0 0x400000 0x800>,
108 <1 0x400000 0x800>;
109 fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
110 0x00000000 0xa0000240 0x00000000>;
111 };
112 };