On Sun, Feb 27, 2022 at 11:16:28PM +0200, Laurent Pinchart wrote:

Hi Sakari,

On Sun, Feb 27, 2022 at 11:07:23PM +0200, Sakari Ailus wrote:

quoted

On Sun, Feb 27, 2022 at 10:33:51PM +0200, Laurent Pinchart wrote:

quoted

Add a new dt-bindings/media/video-interfaces.h header that defines
macros corresponding to the bus types from media/video-interfaces.yaml.
This allows avoiding hardcoded constants in device tree sources.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 include/dt-bindings/media/video-interfaces.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 include/dt-bindings/media/video-interfaces.h

diff --git a/include/dt-bindings/media/video-interfaces.h b/include/dt-bindings/media/video-interfaces.h
new file mode 100644
index 000000000000..e38058e1cca7
--- /dev/null
+++ b/include/dt-bindings/media/video-interfaces.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __DT_BINDINGS_MEDIA_VIDEO_INTERFACES_H__
+#define __DT_BINDINGS_MEDIA_VIDEO_INTERFACES_H__
+
+#define MEDIA_BUS_TYPE_CSI2_CPHY		1
+#define MEDIA_BUS_TYPE_CSI1			2
+#define MEDIA_BUS_TYPE_CCP2			3
+#define MEDIA_BUS_TYPE_CSI2_DPHY		4
+#define MEDIA_BUS_TYPE_PARALLEL			5

I've been long thinkin of renaming "PARALLEL" as "BT.601" which it really
is. I don't mind postponing that, but I think you could as well start here.
Up to you.

I think it's a good idea, but we then need to decide what to do with
other types of parallel buses. Let's start this discussion now, and
implement it in a patch on top of this series.

5 and what it means is an ABI. If it is ambiguous and needs to be more 
specific, then you need new numbers for all of those specific types.

If it is just a rename, I prefer it is done from the start.

quoted

Should this be somehow visible in video-interfaces.yaml?

I wish we could use macros in .yaml files instead of numerical values,
but I don't think that's possible. I can do this:

   bus-type:
     $ref: /schemas/types.yaml#/definitions/uint32
     enum:
-      - 1 # MIPI CSI-2 C-PHY
-      - 2 # MIPI CSI1
-      - 3 # CCP2
-      - 4 # MIPI CSI-2 D-PHY
-      - 5 # Parallel
-      - 6 # BT.656
+      - 1 # MIPI CSI-2 C-PHY (MEDIA_BUS_TYPE_CSI2_CPHY)
+      - 2 # MIPI CSI1 (MEDIA_BUS_TYPE_CSI1)
+      - 3 # CCP2 (MEDIA_BUS_TYPE_CCP2)
+      - 4 # MIPI CSI-2 D-PHY (MEDIA_BUS_TYPE_CSI2_DPHY)
+      - 5 # Parallel (MEDIA_BUS_TYPE_PARALLEL)
+      - 6 # BT.656 (MEDIA_BUS_TYPE_BT656)

Seems a bit redundant to have both comment text and define. The only 
part missing from the defines is 'MIPI'.

     description:
-      Data bus type.
+      Data bus type. Use the macros listed above (defined in
+      dt-bindings/video-interfaces.h) instead of numerical values.

Any better proposal ?

quoted

quoted

+#define MEDIA_BUS_TYPE_BT656			6
+
+#endif /* __DT_BINDINGS_MEDIA_VIDEO_INTERFACES_H__ */

-- 
Regards,

Laurent Pinchart