| 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. |
| |
| - fsl,burst-clk-enable For "fsl,imx50-weim" and "fsl,imx6q-weim" type of |
| devices, the presence of this property indicates that |
| the weim bus should operate in Burst Clock Mode. |
| |
| - fsl,continuous-burst-clk Make Burst Clock to output continuous clock. |
| Without this option Burst Clock will output clock |
| only when necessary. This takes effect only if |
| "fsl,burst-clk-enable" is set. |
| |
| 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 get the CS indexes from the address |
| ranges in 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@21b8000 { |
| 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>; |
| }; |
| }; |
| |
| Example for an imx6q-based board, a multi-chipselect device connected to WEIM: |
| |
| In this case, both chip select 0 and 1 will be configured with the same timing |
| array values. |
| |
| weim: weim@21b8000 { |
| compatible = "fsl,imx6q-weim"; |
| reg = <0x021b8000 0x4000>; |
| clocks = <&clks 196>; |
| #address-cells = <2>; |
| #size-cells = <1>; |
| ranges = <0 0 0x08000000 0x02000000 |
| 1 0 0x0a000000 0x02000000 |
| 2 0 0x0c000000 0x02000000 |
| 3 0 0x0e000000 0x02000000>; |
| fsl,weim-cs-gpr = <&gpr>; |
| |
| acme@0 { |
| compatible = "acme,whatever"; |
| reg = <0 0 0x100>, <0 0x400000 0x800>, |
| <1 0x400000 0x800>; |
| fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100 |
| 0x00000000 0xa0000240 0x00000000>; |
| }; |
| }; |