| 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; |
| }; |
