[v2,1/4] media: dt-bindings: Add property to describe CSI-2 C-PHY line orders

Commit Message

Niklas Söderlund Nov. 21, 2024, 1:41 p.m. UTC

Each data lane on a CSI-2 C-PHY bus uses three phase encoding and is
constructed from three physical wires. The wires are referred to as A, B
and C and their default order is ABC. However to ease hardware design
the specification allows for the wires to be switched in any order.

Add a vendor neutral property to describe the line order used. The
property name 'line-orders', the possible values it can be assigned and
there names are taken from the MIPI Discovery and Configuration (DisCo)
Specification for Imaging.

Signed-off-by: Niklas Söderlund <[e-mail]>
---
* Changes since v1
- Add missing 'items' node.
- Improve usage of should and must it the property description as
  suggested by Sakari, thanks!
---
 .../bindings/media/video-interfaces.yaml      | 21 +++++++++++++++++++
 include/dt-bindings/media/video-interfaces.h  |  7 +++++++
 2 files changed, 28 insertions(+)

Patch

diff --git a/Documentation/devicetree/bindings/media/video-interfaces.yaml b/Documentation/devicetree/bindings/media/video-interfaces.yaml
index 26e3e7d7c67b..038e85b45bef 100644
--- a/Documentation/devicetree/bindings/media/video-interfaces.yaml
+++ b/Documentation/devicetree/bindings/media/video-interfaces.yaml
@@ -210,6 +210,27 @@  properties:
       lane-polarities property is omitted, the value must be interpreted as 0
       (normal). This property is valid for serial busses only.
 
+  line-orders:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 8
+    items:
+      enum:
+        - 0 # ABC
+        - 1 # ACB
+        - 2 # BAC
+        - 3 # BCA
+        - 4 # CAB
+        - 5 # CBA
+    description:
+      An array of line orders of the CSI-2 C-PHY data lanes. The order of the
+      lanes are the same as in data-lanes property. Valid values are 0-5 as
+      defined in the MIPI Discovery and Configuration (DisCo) Specification for
+      Imaging. The length of the array must be the same length as the
+      data-lanes property. If the line-orders property is omitted, the value
+      shall be interpreted as 0 (ABC). This property is valid for CSI-2 C-PHY
+      busses only.
+
   strobe:
     $ref: /schemas/types.yaml#/definitions/uint32
     enum: [ 0, 1 ]
diff --git a/include/dt-bindings/media/video-interfaces.h b/include/dt-bindings/media/video-interfaces.h
index 68ac4e05e37f..88b9d05d8075 100644
--- a/include/dt-bindings/media/video-interfaces.h
+++ b/include/dt-bindings/media/video-interfaces.h
@@ -13,4 +13,11 @@ 
 #define MEDIA_BUS_TYPE_PARALLEL			5
 #define MEDIA_BUS_TYPE_BT656			6
 
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_ABC	0
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_ACB	1
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_BAC	2
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_BCA	3
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_CAB	4
+#define MEDIA_BUS_CSI2_CPHY_LINE_ORDER_CBA	5
+
 #endif /* __DT_BINDINGS_MEDIA_VIDEO_INTERFACES_H__ */