[RFC PATCH v3 03/11] media: dt-bindings: media: Add bindings for bcm2835-unicam

[Jean-Michel Hautbois]

Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
camera interface. Also add a MAINTAINERS entry for it.

Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Signed-off-by: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxxxxxxxx>
---
Dave: I assumed you were the maintainer for this file, as I based it on the
bcm2835-unicam.txt file. Are  you happy to be added directly as the
maintainer, or should this be specified as "Raspberry Pi Kernel
Maintenance <kernel-list@xxxxxxxxxxxxxxx>"
---
 .../bindings/media/brcm,bcm2835-unicam.yaml   | 107 ++++++++++++++++++
 MAINTAINERS                                   |   7 ++
 2 files changed, 114 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml

diff --git a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
new file mode 100644
index 000000000000..5bf41a8834fa
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM283x Camera Interface (Unicam)
+
+maintainers:
+  - Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
+
+description: |-
+  The Unicam block on BCM283x SoCs is the receiver for either
+  CSI-2 or CCP2 data from image sensors or similar devices.
+
+  The main platform using this SoC is the Raspberry Pi family of boards.
+  On the Pi the VideoCore firmware can also control this hardware block,
+  and driving it from two different processors will cause issues.
+  To avoid this, the firmware checks the device tree configuration
+  during boot. If it finds device tree nodes starting by csi then
+  it will stop the firmware accessing the block, and it can then
+  safely be used via the device tree binding.
+
+properties:
+  compatible:
+    const: brcm,bcm2835-unicam
+
+  reg:
+    maxItems: 2
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: Clock for the camera.
+      - description: Clock for the vpu.
+
+  clock-names:
+    items:
+      - const: lp
+      - const: vpu
+
+  power-domains:
+    items:
+      - description: Unicam power domain
+
+  num-data-lanes:
+    items:
+      - enum: [ 2, 4 ]
+
+  port:
+    additionalProperties: false
+    $ref: /schemas/graph.yaml#/$defs/port-base
+
+    properties:
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          data-lanes: true
+          link-frequencies: true
+
+        required:
+          - data-lanes
+          - link-frequencies
+
+    required:
+      - endpoint
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - power-domains
+  - num-data-lanes
+  - port
+
+additionalProperties: False
+
+examples:
+  - |
+    #include <dt-bindings/clock/bcm2835.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/power/raspberrypi-power.h>
+    csi1: csi@7e801000 {
+        compatible = "brcm,bcm2835-unicam";
+        reg = <0x7e801000 0x800>,
+              <0x7e802004 0x4>;
+        interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clocks BCM2835_CLOCK_CAM1>,
+                 <&firmware_clocks 4>;
+        clock-names = "lp", "vpu";
+        power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>;
+        num-data-lanes = <2>;
+        port {
+                csi1_ep: endpoint {
+                        remote-endpoint = <&imx219_0>;
+                        data-lanes = <1 2>;
+                        link-frequencies = /bits/ 64 <456000000>;
+                };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index a0770a861ca4..29344ea86847 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3670,6 +3670,13 @@ N:	bcm113*
 N:	bcm216*
 N:	kona
 
+BROADCOM BCM2835 CAMERA DRIVER
+M:	Raspberry Pi Kernel Maintenance <kernel-list@xxxxxxxxxxxxxxx>
+L:	linux-media@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
+F:	arch/arm/boot/dts/bcm283x*
+
 BROADCOM BCM47XX MIPS ARCHITECTURE
 M:	Hauke Mehrtens <hauke@xxxxxxxxxx>
 M:	Rafał Miłecki <zajec5@xxxxxxxxx>
-- 
2.32.0