Device tree bindings for i.MX Wireless External Interface Module (WEIM)
The term "wireless" does not imply that the WEIM is literally an interface
without wires. It simply means that this module was originally designed for
wireless and mobile applications that use low-power technology.
The actual devices are instantiated from the child nodes of a WEIM node.
Required properties:
- compatible: Should contain one of the following:
"fsl,imx1-weim"
"fsl,imx27-weim"
"fsl,imx51-weim"
"fsl,imx50-weim"
"fsl,imx6q-weim"
- reg: A resource specifier for the register space
(see the example below)
- clocks: the clock, see the example below.
- #address-cells: Must be set to 2 to allow memory address translation
- #size-cells: Must be set to 1 to allow CS address passing
- ranges: Must be set up to reflect the memory layout with four
integer values for each chip-select line in use:
<cs-number> 0 <physical address of mapping> <size>
Optional properties:
- fsl,weim-cs-gpr: For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
devices, it should be the phandle to the system General
Purpose Register controller that contains WEIM CS GPR
register, e.g. IOMUXC_GPR1 on i.MX6Q. IOMUXC_GPR1[11:0]
should be set up as one of the following 4 possible
values depending on the CS space configuration.
IOMUXC_GPR1[11:0] CS0 CS1 CS2 CS3
---------------------------------------------
05 128M 0M 0M 0M
033 64M 64M 0M 0M
0113 64M 32M 32M 0M
01111 32M 32M 32M 32M
In case that the property is absent, the reset value or
what bootloader sets up in IOMUXC_GPR1[11:0] will be
used.
Timing property for child nodes. It is mandatory, not optional.
- fsl,weim-cs-timing: The timing array, contains timing values for the
child node. We can get the CS index from the child
node's "reg" property. The number of registers depends
on the selected chip.
For i.MX1, i.MX21 ("fsl,imx1-weim") there are two
registers: CSxU, CSxL.
For i.MX25, i.MX27, i.MX31 and i.MX35 ("fsl,imx27-weim")
there are three registers: CSCRxU, CSCRxL, CSCRxA.
For i.MX50, i.MX53 ("fsl,imx50-weim"),
i.MX51 ("fsl,imx51-weim") and i.MX6Q ("fsl,imx6q-weim")
there are six registers: CSxGCR1, CSxGCR2, CSxRCR1,
CSxRCR2, CSxWCR1, CSxWCR2.
Example for an imx6q-sabreauto board, the NOR flash connected to the WEIM:
weim: weim@021b8000 {
compatible = "fsl,imx6q-weim";
reg = <0x021b8000 0x4000>;
clocks = <&clks 196>;
#address-cells = <2>;
#size-cells = <1>;
ranges = <0 0 0x08000000 0x08000000>;
fsl,weim-cs-gpr = <&gpr>;
nor@0,0 {
compatible = "cfi-flash";
reg = <0 0 0x02000000>;
#address-cells = <1>;
#size-cells = <1>;
bank-width = <2>;
fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
0x0000c000 0x1404a38e 0x00000000>;
};
};
