dt-bindings: Document the dmas and dma-names properties for VC4 HDMI

These are optional, but necessary for HDMI audio support.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170227202803.12855-1-eric@anholt.net

diff --git a/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt b/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
index 34c7fddcea394f70c0d06191a267382dff6be090..ca02d3e4db91738ac5d87d7e235e0f9de8a56b5e 100644 (file)
--- a/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
+++ b/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
@@ -34,6 +34,9 @@ Optional properties for HDMI:
 - hpd-gpios:   The GPIO pin for HDMI hotplug detect (if it doesn't appear
                  as an interrupt/status bit in the HDMI controller
                  itself).  See bindings/pinctrl/brcm,bcm2835-gpio.txt
+- dmas:                Should contain one entry pointing to the DMA channel used to
+               transfer audio data
+- dma-names:   Should contain "audio-rx"
 
 Required properties for DPI:
 - compatible:  Should be "brcm,bcm2835-dpi"