[PATCH v3 13/24] platform: add video-multiplexer subdevice driver
From: sakari.ailus@iki.fi (Sakari Ailus)
Date: 2017-02-07 20:58:43
Also in:
linux-devicetree, linux-media, lkml
Hi Steve, On Fri, Jan 06, 2017 at 06:11:31PM -0800, Steve Longerbeam wrote:
quoted hunk ↗ jump to hunk
From: Philipp Zabel <p.zabel@pengutronix.de> This driver can handle SoC internal and external video bus multiplexers, controlled either by register bit fields or by a GPIO. The subdevice passes through frame interval and mbus configuration of the active input to the output side. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> -- - fixed a cut&paste error in vidsw_remove(): v4l2_async_register_subdev() should be unregister. - added media_entity_cleanup() and v4l2_device_unregister_subdev() to vidsw_remove(). - there was a line left over from a previous iteration that negated the new way of determining the pad count just before it which has been removed (num_pads = of_get_child_count(np)). - Philipp Zabel has developed a set of patches that allow adding to the subdev async notifier waiting list using a chaining method from the async registered callbacks (v4l2_of_subdev_registered() and the prep patches for that). For now, I've removed the use of v4l2_of_subdev_registered() for the vidmux driver's registered callback. This doesn't affect the functionality of this driver, but allows for it to be merged now, before adding the chaining support. Signed-off-by: Steve Longerbeam <redacted> --- .../bindings/media/video-multiplexer.txt | 59 +++ drivers/media/platform/Kconfig | 8 + drivers/media/platform/Makefile | 2 + drivers/media/platform/video-multiplexer.c | 472 +++++++++++++++++++++ 4 files changed, 541 insertions(+) create mode 100644 Documentation/devicetree/bindings/media/video-multiplexer.txt create mode 100644 drivers/media/platform/video-multiplexer.cdiff --git a/Documentation/devicetree/bindings/media/video-multiplexer.txt b/Documentation/devicetree/bindings/media/video-multiplexer.txt new file mode 100644 index 0000000..9d133d9 --- /dev/null +++ b/Documentation/devicetree/bindings/media/video-multiplexer.txt@@ -0,0 +1,59 @@ +Video Multiplexer +================= + +Video multiplexers allow to select between multiple input ports. Video received +on the active input port is passed through to the output port. Muxes described +by this binding may be controlled by a syscon register bitfield or by a GPIO. + +Required properties: +- compatible : should be "video-multiplexer" +- reg: should be register base of the register containing the control bitfield +- bit-mask: bitmask of the control bitfield in the control register +- bit-shift: bit offset of the control bitfield in the control register +- gpios: alternatively to reg, bit-mask, and bit-shift, a single GPIO phandle + may be given to switch between two inputs +- #address-cells: should be <1> +- #size-cells: should be <0> +- port@*: at least three port nodes containing endpoints connecting to the + source and sink devices according to of_graph bindings. The last port is + the output port, all others are inputs. + +Example: + +syscon { + compatible = "syscon", "simple-mfd"; + + mux {
Could you use standardised properties for this, i.e. ones defined in Documentation/devicetree/bindings/media/video-interfaces.txt ? This is very similar to another patch "[PATCH] devicetree: Add video bus switch" posted by Pavel Machek recently. The problem with that is also similar than with this one: how to pass the CSI-2 bus configuration to the receiver. There's some discussion here: <URL:http://www.spinics.net/lists/linux-media/msg109493.html> As Laurent already suggested, I think we should have a common solution for the problem that, besides conveying the bus parameters to the receiver, also encompasses CSI-2 virtual channels and data types. That would mean finishing the series of patches in the branch I believe Laurent already quoted here.
+ compatible = "video-multiplexer";
+ /* Single bit (1 << 19) in syscon register 0x04: */
+ reg = <0x04>;
+ bit-mask = <1>;
+ bit-shift = <19>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port at 0 {
+ reg = <0>;
+
+ mux_in0: endpoint {
+ remote-endpoint = <&video_source0_out>;
+ };
+ };
+
+ port at 1 {
+ reg = <1>;
+
+ mux_in1: endpoint {
+ remote-endpoint = <&video_source1_out>;
+ };
+ };
+
+ port at 2 {
+ reg = <2>;
+
+ mux_out: endpoint {
+ remote-endpoint = <&capture_interface_in>;
+ };
+ };
+ };
+};-- Kind regards, Sakari Ailus e-mail: sakari.ailus at iki.fi XMPP: sailus at retiisi.org.uk