Re: [PATCH v4 2/6] media: max9286: Implement set_routing

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

Another comment.

On Fri, Dec 17, 2021 at 03:56:48AM +0200, Laurent Pinchart wrote:
> On Thu, Dec 16, 2021 at 06:47:42PM +0100, Jacopo Mondi wrote:
> > Add the set_routing() subdev operation to allow userspace to configure
> > routing on the max9286 deserializer.
> > 
> > Implement route verification but do not take routing into consideration
> > when configuring the CSI-2 output and pixel rate yet.
> > 
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  drivers/media/i2c/max9286.c | 89 ++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 87 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index 1b9ff537d08e..eb76acdb2cd9 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -832,6 +832,91 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
> >  	return 0;
> >  }
> >  
> > +static int max9286_routing_validate(struct max9286_priv *priv,
> > +				    struct v4l2_subdev_krouting *routing)
> > +{
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	ret = v4l2_subdev_routing_validate_1_to_1(routing);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 * Make sure all routes points to the single source pad which can have
> > +	 * up to 4 streams. All routes shall start from a sink pad and shall not
> > +	 * have more than one sink stream. The GMSL link for the sink has to be
> > +	 * enabled.
> > +	 */
> > +	for (i = 0; i < routing->num_routes; ++i) {
> > +		const struct v4l2_subdev_route *route = &routing->routes[i];
> > +		struct max9286_source *source = &priv->sources[i];

There's no need to initialize source here.

> > +
> > +		if (route->source_pad != MAX9286_SRC_PAD ||
> > +		    route->source_stream > 4) {
> > +			dev_err(&priv->client->dev,
> > +				"Invalid (%u,%u) source in route %u\n",
> > +				route->source_pad, route->source_stream, i);
> > +			return -EINVAL;
> > +		}
> > +
> > +		if (route->sink_pad >= MAX9286_N_SINKS ||
> > +		    route->sink_stream != 0) {
> > +			dev_err(&priv->client->dev,
> > +				"Invalid (%u,%u) sink in route %u\n",
> > +				route->sink_pad, route->sink_stream, i);
> > +			return -EINVAL;
> > +		}
> > +
> > +		source = &priv->sources[route->sink_pad];
> > +		if (!source->fwnode) {
> > +			dev_err(&priv->client->dev,
> > +				"Cannot set route for non-active source %u\n",
> > +				route->sink_pad);
> > +			return -EINVAL;
> > +		}
> > +	}
> 
> Apart from from possibly using the new helper I've submitted, this looks
> fine.

The helper should allow to drop the source_pad and sink_pad checks, but
the source_stream and sink_stream checks are still needed. This may be
possible to factorize in the helper too, let's see when we'll have more
use cases.

> > +
> > +	return 0;
> > +}
> > +
> > +static int _max9286_set_routing(struct v4l2_subdev *sd,
> > +				struct v4l2_subdev_state *state,
> > +				struct v4l2_subdev_krouting *routing)
> > +{
> > +	struct max9286_priv *priv = sd_to_max9286(sd);
> > +	int ret;
> > +
> > +	ret = max9286_routing_validate(priv, routing);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* Re-initialize the format on a routing change. */
> > +	ret = v4l2_subdev_set_routing_with_fmt(sd, state, routing,
> > +					       &max9286_default_format);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return 0;
> > +}
> > +
> > +static int max9286_set_routing(struct v4l2_subdev *sd,
> > +			       struct v4l2_subdev_state *state,
> > +			       enum v4l2_subdev_format_whence which,
> > +			       struct v4l2_subdev_krouting *routing)
> > +{
> > +	struct max9286_priv *priv = sd_to_max9286(sd);
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	v4l2_subdev_lock_state(state);
> > +
> 
> I'd drop the blank line, or add one before the unlock call.
> 
> > +	ret = _max9286_set_routing(sd, state, routing);
> > +	v4l2_subdev_unlock_state(state);
> > +
> > +	return ret;
> > +}
> > +
> >  static int max9286_init_cfg(struct v4l2_subdev *sd,
> >  			    struct v4l2_subdev_state *state)
> >  {
> > @@ -858,8 +943,7 @@ static int max9286_init_cfg(struct v4l2_subdev *sd,
> >  	routing.routes = routes;
> >  
> >  	v4l2_subdev_lock_state(state);
> > -	ret = v4l2_subdev_set_routing_with_fmt(sd, state, &routing,
> > -					       &max9286_default_format);
> > +	ret = _max9286_set_routing(sd, state, &routing);
> >  	v4l2_subdev_unlock_state(state);
> >  
> >  	return ret;
> > @@ -874,6 +958,7 @@ static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
> >  	.enum_mbus_code = max9286_enum_mbus_code,
> >  	.get_fmt	= max9286_get_fmt,
> >  	.set_fmt	= max9286_set_fmt,
> > +	.set_routing	= max9286_set_routing,
> >  };
> >  
> >  static const struct v4l2_subdev_ops max9286_subdev_ops = {

-- 
Regards,

Laurent Pinchart