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-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-samsung.txt52
1 files changed, 48 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
index 8f50fe5..f1e5dfe 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
@@ -11,14 +11,15 @@ Required properties:
<[phandle of the gpio controller node]
[pin number within the gpio controller]
[mux function]
- [pull up/down]
+ [flags and pull up/down]
[drive strength]>
Values for gpio specifier:
- Pin number: is a value between 0 to 7.
- - Pull Up/Down: 0 - Pull Up/Down Disabled.
- 1 - Pull Down Enabled.
- 3 - Pull Up Enabled.
+ - 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,
@@ -38,3 +39,46 @@ Example:
#gpio-cells = <4>;
gpio-controller;
};
+
+
+Samsung S3C24XX GPIO Controller
+
+Required properties:
+- compatible: Compatible property value should be "samsung,s3c24xx-gpio".
+
+- reg: Physical base address of the controller and length of memory mapped
+ region.
+
+- #gpio-cells: Should be 3. 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]
+
+ Values for gpio specifier:
+ - Pin number: depending on the controller a number from 0 up to 15.
+ - Mux function: Depending on the SoC and the gpio bank the gpio can be set
+ as input, output or a special function
+ - Flags and Pull Up/Down: the values to use differ for the individual SoCs
+ example S3C2416/S3C2450:
+ 0 - Pull Up/Down Disabled.
+ 1 - Pull Down Enabled.
+ 2 - Pull Up Enabled.
+ Bit 16 (0x00010000) - Input is active low.
+ Consult the user manual for the correct values of Mux and Pull Up/Down.
+
+- gpio-controller: Specifies that the node is a gpio controller.
+- #address-cells: should be 1.
+- #size-cells: should be 1.
+
+Example:
+
+ gpa: gpio-controller@56000000 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "samsung,s3c24xx-gpio";
+ reg = <0x56000000 0x10>;
+ #gpio-cells = <3>;
+ gpio-controller;
+ };