Re: [PATCH v6 03/13] media: v4l2-fwnode: add initial connector parsing support

[Mauro Carvalho Chehab <mchehab@kernel.org>]

Em Mon, 6 May 2019 12:10:41 +0200
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> On 4/15/19 2:44 PM, Marco Felsch wrote:
> > The patch adds the initial connector parsing code, so we can move from a
> > driver specific parsing code to a generic one. Currently only the
> > generic fields and the analog-connector specific fields are parsed. Parsing
> > the other connector specific fields can be added by a simple callbacks.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> > ---
> > [1] https://patchwork.kernel.org/cover/10794703/
> > 
> > v6:
> > - use 'unsigned int' count var
> > - fix comment and style issues
> > - place '/* fall through */' to correct places
> > - fix error handling and cleanup by releasing fwnode
> > - drop vga and dvi parsing support as those connectors are rarely used
> >   these days
> > 
> > v5:
> > - s/strlcpy/strscpy/
> > 
> > v2-v4:
> > - nothing since the patch was squashed from series [1] into this
> >   series.
> > 
> >  drivers/media/v4l2-core/v4l2-fwnode.c | 111 ++++++++++++++++++++++++++
> >  include/media/v4l2-fwnode.h           |  16 ++++
> >  2 files changed, 127 insertions(+)
> > 
> > diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> > index 20571846e636..f1cca95c8fef 100644
> > --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> > +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> > @@ -592,6 +592,117 @@ void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
> >  }
> >  EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
> >  
> > +static const struct v4l2_fwnode_connector_conv {
> > +	enum v4l2_connector_type type;
> > +	const char *name;
> > +} connectors[] = {
> > +	{
> > +		.type = V4L2_CON_COMPOSITE,
> > +		.name = "composite-video-connector",
> > +	}, {
> > +		.type = V4L2_CON_SVIDEO,
> > +		.name = "svideo-connector",
> > +	}, {
> > +		.type = V4L2_CON_HDMI,
> > +		.name = "hdmi-connector",
> > +	},
> > +};
> > +
> > +static enum v4l2_connector_type
> > +v4l2_fwnode_string_to_connector_type(const char *con_str)
> > +{
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(connectors); i++)
> > +		if (!strcmp(con_str, connectors[i].name))
> > +			return connectors[i].type;
> > +
> > +	/* no valid connector found */
> > +	return V4L2_CON_UNKNOWN;
> > +}
> > +
> > +static int
> > +v4l2_fwnode_connector_parse_analog(struct fwnode_handle *fwnode,
> > +				   struct v4l2_fwnode_connector *vc)
> > +{
> > +	u32 tvnorms;
> > +	int ret;
> > +
> > +	ret = fwnode_property_read_u32(fwnode, "tvnorms", &tvnorms);
> > +
> > +	/* tvnorms is optional */
> > +	vc->connector.analog.supported_tvnorms = ret ? V4L2_STD_ALL : tvnorms;
> > +
> > +	return 0;
> > +}
> > +
> > +int v4l2_fwnode_parse_connector(struct fwnode_handle *__fwnode,
> > +				struct v4l2_fwnode_connector *connector)
> > +{
> > +	struct fwnode_handle *fwnode;
> > +	struct fwnode_endpoint __ep;
> > +	const char *c_type_str, *label;
> > +	int ret;
> > +
> > +	memset(connector, 0, sizeof(*connector));
> > +
> > +	fwnode = fwnode_graph_get_remote_port_parent(__fwnode);
> > +	if (!fwnode)
> > +		return -EINVAL;
> > +
> > +	/* parse all common properties first */
> > +	/* connector-type is stored within the compatible string */
> > +	ret = fwnode_property_read_string(fwnode, "compatible", &c_type_str);
> > +	if (ret) {
> > +		fwnode_handle_put(fwnode);
> > +		return -EINVAL;
> > +	}
> > +
> > +	connector->type = v4l2_fwnode_string_to_connector_type(c_type_str);
> > +
> > +	fwnode_graph_parse_endpoint(__fwnode, &__ep);
> > +	connector->remote_port = __ep.port;
> > +	connector->remote_id = __ep.id;
> > +
> > +	ret = fwnode_property_read_string(fwnode, "label", &label);
> > +	if (!ret) {
> > +		/* ensure label doesn't exceed V4L2_CONNECTOR_MAX_LABEL size */
> > +		strscpy(connector->label, label, V4L2_CONNECTOR_MAX_LABEL);
> > +	} else {
> > +		/*
> > +		 * labels are optional, if none is given create one:
> > +		 * <connector-type-string>@port<endpoint_port>/ep<endpoint_id>
> > +		 */
> > +		snprintf(connector->label, V4L2_CONNECTOR_MAX_LABEL,
> > +			 "%s@port%u/ep%u", c_type_str, connector->remote_port,
> > +			 connector->remote_id);
> > +	}
> > +
> > +	/* now parse the connector specific properties */
> > +	switch (connector->type) {
> > +	case V4L2_CON_COMPOSITE:
> > +		/* fall through */
> > +	case V4L2_CON_SVIDEO:
> > +		ret = v4l2_fwnode_connector_parse_analog(fwnode, connector);
> > +		break;
> > +	case V4L2_CON_HDMI:
> > +		pr_warn("Connector specific parsing is currently not supported for %s\n",
> > +			c_type_str);  
> 
> Why warn? Just drop this.

good point. I would prefer to have some warning here, in order to warn a
developer that might be using it that this part of the code would require 
some change.

perhaps pr_warn_once()?

> 
> > +		ret = 0;
> > +		break;
> > +	case V4L2_CON_UNKNOWN:
> > +		/* fall through */
> > +	default:
> > +		pr_err("Unknown connector type\n");
> > +		ret = -EINVAL;
> > +	};
> > +
> > +	fwnode_handle_put(fwnode);
> > +
> > +	return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_connector);
> > +
> >  static int
> >  v4l2_async_notifier_fwnode_parse_endpoint(struct device *dev,
> >  					  struct v4l2_async_notifier *notifier,
> > diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
> > index f4df1b95c5ef..e072f2915ddb 100644
> > --- a/include/media/v4l2-fwnode.h
> > +++ b/include/media/v4l2-fwnode.h
> > @@ -269,6 +269,22 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
> >   */
> >  void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
> >  
> > +/**
> > + * v4l2_fwnode_parse_connector() - parse the connector on endpoint
> > + * @fwnode: pointer to the endpoint's fwnode handle where the connector is
> > + *          connected to
> > + * @connector: pointer to the V4L2 fwnode connector data structure
> > + *
> > + * Fill the connector data structure with the connector type, label and the
> > + * endpoint id and port where the connector belongs to. If no label is present
> > + * a unique one will be created. Labels with more than 40 characters are cut.
> > + *
> > + * Return: %0 on success or a negative error code on failure:
> > + *	   %-EINVAL on parsing failure
> > + */
> > +int v4l2_fwnode_parse_connector(struct fwnode_handle *fwnode,
> > +				struct v4l2_fwnode_connector *connector);
> > +
> >  /**
> >   * typedef parse_endpoint_func - Driver's callback function to be called on
> >   *	each V4L2 fwnode endpoint.
> >   
> 
> Regards,
> 
> 	Hans



Thanks,
Mauro