Thread (9 messages) 9 messages, 2 authors, 2016-11-30

Re: [PATCH v2 3/4] dt-bindings: display: add Amlogic Meson DRM Bindings

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2016-11-30 15:56:39
Also in: dri-devel, linux-amlogic, linux-arm-kernel, lkml

Hi Neil,

Thank you for the patch.

On Wednesday 30 Nov 2016 16:43:44 Neil Armstrong wrote:
quoted hunk ↗ jump to hunk
Signed-off-by: Neil Armstrong <redacted>
---
.../bindings/display/meson/meson-drm.txt           | 101 ++++++++++++++++++
1 file changed, 101 insertions(+)
create mode 100644
Documentation/devicetree/bindings/display/meson/meson-drm.txt
diff --git a/Documentation/devicetree/bindings/display/meson/meson-drm.txt
b/Documentation/devicetree/bindings/display/meson/meson-drm.txt new file
mode 100644
index 0000000..e52869a
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/meson/meson-drm.txt
@@ -0,0 +1,101 @@
+Amlogic Meson Display Controller
+================================
+
+The Amlogic Meson Display controller is composed of several components
+that are going to be documented below:
+
+DMC|---------------VPU (Video Processing Unit)------------|------HHI------|
+   | vd1   _______     _____________    _____________     |               |
+D  |-------|      |----|            |   |            |    |   HDMI PLL    |
+D  | vd2   | VIU  |    | Video Post |   | Video Encs |<---|-----VCLK      |
+R  |-------|      |----| Processing |   |            |    |               |
+   | osd2  |      |    |            |---| Enci ------|----|-----VDAC------|
+R  |-------| CSC  |----| Scalers    |   | Encp ------|----|----HDMI-TX----|
+A  | osd1  |      |    | Blenders   |   | Encl-------|----|---------------|
+M  |-------|______|----|____________|   |____________|    |               |
+___|______________________________________________________|_______________|
+
+
+VIU: Video Input Unit
+---------------------
+
+The Video Input Unit is in charge of the pixel scanout from the DDR memory.
+It fetches the frames addresses, stride and parameters from the "Canvas"
memory.
+This part is also in charge of the CSC (Colorspace Conversion).
+It can handle 2 OSD Planes and 2 Video Planes.
+
+VPP: Video Post Processing
+--------------------------
+
+The Video Post Processing is in charge of the scaling and blending of the
+various planes into a single pixel stream.
+There is a special "pre-blending" used by the video planes with a dedicated
+scaler and a "post-blending" to merge with the OSD Planes.
+The OSD planes also have a dedicated scaler for one of the OSD.
+
+VENC: Video Encoders
+--------------------
+
+The VENC is composed of the multiple pixel encoders :
+ - ENCI : Interlace Video encoder for CVBS and Interlace HDMI
+ - ENCP : Progressive Video Encoder for HDMI
+ - ENCL : LCD LVDS Encoder
+The VENC Unit gets a Pixel Clocks (VCLK) from a dedicated HDMI PLL and
clock
+tree and provides the scanout clock to the VPP and VIU.
+The ENCI is connected to a single VDAC for Composite Output.
+The ENCI and ENCP are connected to an on-chip HDMI Transceiver.
+
+Device Tree Bindings:
+---------------------
+
+VPU: Video Processing Unit
+--------------------------
+
+Required properties:
+- compatible: value should be different for each SoC family as :
+	- GXBB (S905) : "amlogic,meson-gxbb-vpu"
+	- GXL (S905X, S905D) : "amlogic,meson-gxl-vpu"
+	- GXM (S912) : "amlogic,meson-gxm-vpu"
+	followed by the common "amlogic,meson-gx-vpu"
+- reg: base address and size of he following memory-mapped regions :
+	- vpu
+	- hhi
+	- dmc
+- reg-names: should contain the names of the previous memory regions
+- interrupts: should contain the VENC Vsync interrupt number
+
+- ports: A ports node with endpoint definitions as defined in
+  Documentation/devicetree/bindings/media/video-interfaces.txt.
+  The first port should be connected to a CVBS connector endpoint if
available.
This is a bit vague, I propose clarifying it with a description similar to the 
one in the renesas,du.txt bindings.

Required nodes:

The connections to the VPU output video ports are modeled using the OF graph
bindings specified in Documentation/devicetree/bindings/graph.txt.

The following table lists for each supported model the port number
corresponding to each DU output.

                Port 0          Port1           Port2           Port3
-----------------------------------------------------------------------------
 R8A7779 (H1)   DPAD 0          DPAD 1          -               -
 R8A7790 (H2)   DPAD            LVDS 0          LVDS 1          -
 R8A7791 (M2-W) DPAD            LVDS 0          -               -
 R8A7792 (V2H)  DPAD 0          DPAD 1          -               -
 R8A7793 (M2-N) DPAD            LVDS 0          -               -
 R8A7794 (E2)   DPAD 0          DPAD 1          -               -
 R8A7795 (H3)   DPAD            HDMI 0          HDMI 1          LVDS
 R8A7796 (M3-W) DPAD            HDMI            LVDS            -

(You should obviously replace the table with Amlogic data)

It doesn't matter if the current driver implementation only supports CVBS, the 
DT bindings can already document the other ports.
+
+Example:
+
+tv: connector {
+	compatible = "composite-video-connector";
+	label = "cvbs";
I'd remove the label here, as it doesn't bring any additional information. 
Unless the board you're using has a label for the connector, in case that 
label should be used.

Apart from that,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+	port {
+		tv_connector_in: endpoint {
+			remote-endpoint = <&cvbs_vdac_out>;
+		};
+	};
+};
+
+vpu: vpu@d0100000 {
+	compatible = "amlogic,meson-gxbb-vpu";
+	reg = <0x0 0xd0100000 0x0 0x100000>,
+	      <0x0 0xc883c000 0x0 0x1000>,
+	      <0x0 0xc8838000 0x0 0x1000>;
+	reg-names = "vpu", "hhi", "dmc";
+	interrupts = <GIC_SPI 3 IRQ_TYPE_EDGE_RISING>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	/* CVBS VDAC output port */
+	port@0 {
+		cvbs_vdac_out: endpoint {
+			reg = <0>;
+			remote-endpoint = <&tv_connector_in>;
+		};
+	};
+};
-- 
Regards,

Laurent Pinchart

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