usb: gadget: gr_udc: Expand devicetree documentation

Provide more information on the two different interrupt cases and more
information of endpoint buffer sizes. Suggested by Mark Rutland.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/Documentation/devicetree/bindings/usb/gr-udc.txt b/Documentation/devicetree/bindings/usb/gr-udc.txt
index 0c5118f..e944522 100644 (file)
--- a/Documentation/devicetree/bindings/usb/gr-udc.txt
+++ b/Documentation/devicetree/bindings/usb/gr-udc.txt
@@ -12,17 +12,23 @@ Required properties:
 
 - reg : Address and length of the register set for the device
 
-- interrupts : Interrupt numbers for this device
+- interrupts : Interrupt numbers for this device. Either one interrupt number
+       for all interrupts, or one for status related interrupts, one for IN
+       endpoint related interrupts and one for OUT endpoint related interrupts.
 
 Optional properties:
 
-- epobufsizes : An array of buffer sizes for OUT endpoints. If the property is
-       not present, or for endpoints outside of the array, 1024 is assumed by
-       the driver.
-
-- epibufsizes : An array of buffer sizes for IN endpoints. If the property is
-       not present, or for endpoints outside of the array, 1024 is assumed by
-       the driver.
+- epobufsizes : Array of buffer sizes for OUT endpoints when they differ
+       from the default size of 1024. The array is indexed by the OUT endpoint
+       number. If the property is present it typically contains one entry for
+       each OUT endpoint of the core. Fewer entries overrides the default sizes
+       only for as many endpoints as the array contains.
+
+- epibufsizes : Array of buffer sizes for IN endpoints when they differ
+       from the default size of 1024. The array is indexed by the IN endpoint
+       number. If the property is present it typically contains one entry for
+       each IN endpoint of the core. Fewer entries overrides the default sizes
+       only for as many endpoints as the array contains.
 
 For further information look in the documentation for the GLIB IP core library:
 http://www.gaisler.com/products/grlib/grip.pdf