Thread (229 messages) 229 messages, 14 authors, 2017-03-26

Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice driver

From: Pavel Machek <hidden>
Date: 2017-02-19 22:12:31
Also in: linux-arm-kernel, linux-media, lkml

Hi!
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>
--
Again, this is slightly non-standard format. Normally changes from v1
go below ---, but in your case it would cut off the signoff...
quoted hunk ↗ jump to hunk
diff --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.
At least three? I guess it is exactly three with the gpio?

Plus you might want to describe which port correspond to which gpio
state/bitfield values...
+struct vidsw {
I knew it: it is secretely a switch! :-).
+static void vidsw_set_active(struct vidsw *vidsw, int active)
+{
+	vidsw->active = active;
+	if (active < 0)
+		return;
+
+	dev_dbg(vidsw->subdev.dev, "setting %d active\n", active);
+
+	if (vidsw->field)
+		regmap_field_write(vidsw->field, active);
+	else if (vidsw->gpio)
+		gpiod_set_value(vidsw->gpio, active);
         else dev_err()...?
	 
+static int vidsw_async_init(struct vidsw *vidsw, struct device_node *node)
+{
+	struct device_node *ep;
+	u32 portno;
+	int numports;
numbports is int, so I guess portno should be, too?
+		portno = endpoint.base.port;
+		if (portno >= numports - 1)
+			continue;
+	if (!pad) {
+		/* Mirror the input side on the output side */
+		cfg->type = vidsw->endpoint[vidsw->active].bus_type;
+		if (cfg->type == V4L2_MBUS_PARALLEL ||
+		    cfg->type == V4L2_MBUS_BT656)
+			cfg->flags = vidsw->endpoint[vidsw->active].bus.parallel.flags;
+	}
Will this need support for other V4L2_MBUS_ values?
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_AUTHOR("Philipp Zabel, Pengutronix");
Normally, MODULE_AUTHOR contains comma separated names of authors,
perhaps with <email@addresses>. Not sure two MODULE_AUTHORs per file
will work.

Thanks,
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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