[RFC PATCH 1/3] media: dt-bindings: media: Add bindings for bcm2835-unicam

[Jean-Michel Hautbois]

Introduce the dt-bindinds documentation for bcm2835 CCP2/CSI2 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   | 103 ++++++++++++++++++
 MAINTAINERS                                   |   6 +
 2 files changed, 109 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..1427514142cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
@@ -0,0 +1,103 @@
+# 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 called csi0 or csi1 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:
+    description:
+      physical base address and length of the register sets for the device.
+    maxItems: 1
+
+  interrupts:
+    description: the IRQ line for this Unicam instance.
+    maxItems: 1
+
+  clocks:
+    description: |-
+      list of clock specifiers, corresponding to entries in clock-names
+      property.
+
+  clock-names:
+    items:
+      - const: lp
+      - const: vpu
+
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - port
+
+additionalProperties: False
+
+examples:
+  - |
+    csi1: csi1@7e801000 {
+        compatible = "brcm,bcm2835-unicam";
+        reg = <0x7e801000 0x800>,
+              <0x7e802004 0x4>;
+        interrupts = <2 7>;
+        clocks = <&clocks BCM2835_CLOCK_CAM1>,
+                 <&firmware_clocks 4>;
+        clock-names = "lp", "vpu";
+        port {
+                csi1_ep: endpoint {
+                        remote-endpoint = <&tc358743_0>;
+                        data-lanes = <1 2>;
+                };
+        };
+    };
+
+    i2c0: i2c@7e205000 {
+        tc358743: csi-hdmi-bridge@0f {
+            compatible = "toshiba,tc358743";
+            reg = <0x0f>;
+            clocks = <&tc358743_clk>;
+            clock-names = "refclk";
+
+            tc358743_clk: bridge-clk {
+                    compatible = "fixed-clock";
+                    #clock-cells = <0>;
+                    clock-frequency = <27000000>;
+            };
+
+            port {
+                    tc358743_0: endpoint {
+                            remote-endpoint = <&csi1_ep>;
+                            clock-lanes = <0>;
+                            data-lanes = <1 2>;
+                            clock-noncontinuous;
+                            link-frequencies =
+                                /bits/ 64 <297000000>;
+                    };
+            };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 269aa4d6b94a..7484255cad31 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3653,6 +3653,12 @@ 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
+
 BROADCOM BCM47XX MIPS ARCHITECTURE
 M:	Hauke Mehrtens <hauke@xxxxxxxxxx>
 M:	Rafał Miłecki <zajec5@xxxxxxxxx>
-- 
2.32.0