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authorJohan Hovold <johan@kernel.org>2017-11-09 18:07:19 +0100
committerRob Herring <robh@kernel.org>2017-11-16 11:01:15 -0600
commitf877918cdd793373fb7a960c72ba3639786e8e8f (patch)
tree4509f3bb46a531d168f535f73dfc3bef2682f965 /Documentation
parentbfebcf54608a749800a171ffd01f7d5b450e9a55 (diff)
downloadlinux-f877918cdd793373fb7a960c72ba3639786e8e8f.tar.bz2
dt-bindings: usb: document hub and host-controller properties
Hub nodes and host-controller nodes with child nodes must specify values for #address-cells (1) and #size-cells (0). Also make the definition of the related reg property a bit more stringent, and add comments to the example source. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/usb/usb-device.txt20
1 files changed, 16 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/usb/usb-device.txt b/Documentation/devicetree/bindings/usb/usb-device.txt
index e0b562e35a0c..1b27cebb47f4 100644
--- a/Documentation/devicetree/bindings/usb/usb-device.txt
+++ b/Documentation/devicetree/bindings/usb/usb-device.txt
@@ -4,22 +4,34 @@ Usually, we only use device tree for hard wired USB device.
The reference binding doc is from:
http://www.devicetree.org/open-firmware/bindings/usb/usb-1_0.ps
+
Required properties:
- compatible: "usbVID,PID", where VID is the vendor id and PID the product id.
The textual representation of VID and PID shall be in lower case hexadecimal
with leading zeroes suppressed. The other compatible strings from the above
standard binding could also be used, but a device adhering to this binding
may leave out all except for "usbVID,PID".
-- reg: the port number which this device is connecting to, the range
- is 1-255.
+- reg: the number of the USB hub port or the USB host-controller port to which
+ this device is attached. The range is 1-255.
+
+
+Required properties for hub nodes with device nodes:
+- #address-cells: shall be 1
+- #size-cells: shall be 0
+
+
+Required properties for host-controller nodes with device nodes:
+- #address-cells: shall be 1
+- #size-cells: shall be 0
+
Example:
-&usb1 {
+&usb1 { /* host controller */
#address-cells = <1>;
#size-cells = <0>;
- hub@1 {
+ hub@1 { /* hub connected to port 1 */
compatible = "usb5e3,608";
reg = <1>;
};