Re: [PATCH v2 1/2] media: dt-bindings: media: i2c: Add MT9M114 camera sensor binding

Hi Sakari,

On Sun, Feb 13, 2022 at 12:12:10AM +0200, Laurent Pinchart wrote:

On Sat, Feb 12, 2022 at 10:33:44PM +0200, Sakari Ailus wrote:

quoted

On Tue, Feb 08, 2022 at 08:47:32PM +0200, Laurent Pinchart wrote:

quoted

On Tue, Feb 08, 2022 at 06:51:01PM +0200, Sakari Ailus wrote:

quoted

On Mon, Feb 07, 2022 at 03:20:54AM +0200, Laurent Pinchart wrote:

quoted

Add device tree binding for the onsemi MT9M114 CMOS camera sensor.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Use graph schema
- Drop unneeded properties
- Rename ON Semiconductor to onsemi
---
 .../bindings/media/i2c/onnn,mt9m114.yaml      | 110 ++++++++++++++++++
 MAINTAINERS                                   |   7 ++
 2 files changed, 117 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml b/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml
new file mode 100644
index 000000000000..55b67833f9a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml

@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/onnn,mt9m114.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: onsemi 1/6-inch 720p CMOS Digital Image Sensor
+
+maintainers:
+  - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+
+description: |-
+  The onsemi MT9M114 is a 1/6-inch 720p (1.26 Mp) CMOS digital image sensor
+  with an active pixel-array size of 1296H x 976V. It is programmable through
+  an I2C interface and outputs image data over a 8-bit parallel or 1-lane MIPI
+  CSI-2 connection.
+
+properties:
+  compatible:
+    const: onnn,mt9m114
+
+  reg:
+    description: I2C device address
+    enum:
+      - 0x48
+      - 0x5d
+
+  clocks:
+    description: EXTCLK clock signal
+    maxItems: 1
+
+  vdd-supply:
+    description:
+      Core digital voltage supply, 1.8V
+
+  vddio-supply:
+    description:
+      I/O digital voltage supply, 1.8V or 2.8V
+
+  vaa-supply:
+    description:
+      Analog voltage supply, 2.8V
+
+  reset-gpios:
+    description: |-
+      Reference to the GPIO connected to the RESET_BAR pin, if any (active
+      low).
+
+  port:
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    additionalProperties: false
+
+    properties:
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        additionalProperties: false
+
+        properties:
+          bus-type:
+            enum: [4, 5, 6]

With bus-type 5, shouldn't you have the parallel interface sync signal
polarity properties? Possibly also others if the hardware supports them.

As far as I can tell, the hardware has fixed polarities for all signals.
Both hsync and vsync (called LINE_VALID and FRAME_VALID here) are active
high.

Right, then you won't need these.

What about the link-frequencies property?

That's something I've meant to ask, should the link-frequencies property
be specified for parallel buses too, or only CSI-2 ?

Any feedback on this ?

We also need to document how a DT writer should select the link
frequencies. The process is complicated, saying that the property is
required without explaining how the values can be computed (EMC
constraints aside, just from a functional point of view) isn't nice. If
you explain this to me, I can put it in a patch :-)

Or on this ? :-)

quoted

quoted

quoted

quoted

+
+          remote-endpoint: true
+
+          # The number and mapping of lanes (for CSI-2), and the bus width and
+          # signal polarities (for parallel and BT.656) are fixed and must not
+          # be specified.
+
+        required:
+          - bus-type
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - vdd-supply
+  - vddio-supply
+  - vaa-supply
+  - port
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        sensor@48 {
+            compatible = "onnn,mt9m114";
+            reg = <0x48>;
+
+            clocks = <&clk24m 0>;
+
+            reset-gpios = <&gpio5 21 GPIO_ACTIVE_LOW>;
+
+            vddio-supply = <&reg_cam_1v8>;
+            vdd-supply = <&reg_cam_1v8>;
+            vaa-supply = <&reg_2p8v>;
+
+            port {
+                endpoint {
+                    bus-type = <4>;
+                    remote-endpoint = <&mipi_csi_in>;
+                };
+            };
+        };
+    };
+...

diff --git a/MAINTAINERS b/MAINTAINERS
index f41088418aae..e9919a359c12 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -13096,6 +13096,13 @@ T:	git git://linuxtv.org/media_tree.git
 F:	drivers/media/i2c/mt9m032.c
 F:	include/media/i2c/mt9m032.h
 
+MT9M114 ONSEMI SENSOR DRIVER
+M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+T:	git git://linuxtv.org/media_tree.git
+F:	Documentation/devicetree/bindings/media/i2c.onnn,mt9m114.yaml
+
 MT9P031 APTINA CAMERA SENSOR
 M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 L:	linux-media@vger.kernel.org

-- 
Regards,

Laurent Pinchart