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

From: Jean-Michel Hautbois
Date: Wed Jan 12 2022 - 12:28:03 EST


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