mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-20 18:23:08 +00:00
42 lines
1.2 KiB
Text
42 lines
1.2 KiB
Text
|
Samsung Exynos4 GPIO Controller
|
||
|
|
|
||
|
|
Required properties:
|
||
|
|
- compatible: Compatible property value should be "samsung,exynos4-gpio>".
|
||
|
|
|
||
|
|
- reg: Physical base address of the controller and length of memory mapped
|
||
|
|
region.
|
||
|
|
|
||
|
|
- #gpio-cells: Should be 4. The syntax of the gpio specifier used by client nodes
|
||
|
|
should be the following with values derived from the SoC user manual.
|
||
|
|
<[phandle of the gpio controller node]
|
||
|
|
[pin number within the gpio controller]
|
||
|
|
[mux function]
|
||
|
|
[flags and pull up/down]
|
||
|
|
[drive strength]>
|
||
|
|
|
||
|
|
Values for gpio specifier:
|
||
|
|
- Pin number: is a value between 0 to 7.
|
||
|
|
- Flags and Pull Up/Down: 0 - Pull Up/Down Disabled.
|
||
|
|
1 - Pull Down Enabled.
|
||
|
|
3 - Pull Up Enabled.
|
||
|
|
Bit 16 (0x00010000) - Input is active low.
|
||
|
|
- Drive Strength: 0 - 1x,
|
||
|
|
1 - 3x,
|
||
|
|
2 - 2x,
|
||
|
|
3 - 4x
|
||
|
|
|
||
|
|
- gpio-controller: Specifies that the node is a gpio controller.
|
||
|
|
- #address-cells: should be 1.
|
||
|
|
- #size-cells: should be 1.
|
||
|
|
|
||
|
|
Example:
|
||
|
|
|
||
|
|
gpa0: gpio-controller@11400000 {
|
||
|
|
#address-cells = <1>;
|
||
|
|
#size-cells = <1>;
|
||
|
|
compatible = "samsung,exynos4-gpio";
|
||
|
|
reg = <0x11400000 0x20>;
|
||
|
|
#gpio-cells = <4>;
|
||
|
|
gpio-controller;
|
||
|
|
};
|