Linux-Devicetree Archive on lore.kernel.org
 help / color / Atom feed
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	Sam Ravnborg <sam@ravnborg.org>, Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>,
	dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v10 1/2] of_graph: add of_graph_is_present()
Date: Wed, 1 Jul 2020 10:55:52 +0300
Message-ID: <20200701075552.GJ5963@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20200701074232.13632-2-digetx@gmail.com>

Hi Dmitry,

Thank you for the patch.

On Wed, Jul 01, 2020 at 10:42:31AM +0300, Dmitry Osipenko wrote:
> In some cases it's very useful to silently check whether port node exists
> at all in a device-tree before proceeding with parsing the graph. The DRM
> bridges code is one example of such case where absence of a graph in a
> device-tree is a legit condition.
> 
> This patch adds of_graph_is_present() which returns true if given
> device-tree node contains OF graph port.
> 
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/of/property.c    | 23 +++++++++++++++++++++++
>  include/linux/of_graph.h |  6 ++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 6a5760f0d6cd..fed7229d9d9f 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -29,6 +29,29 @@
>  
>  #include "of_private.h"
>  
> +/**
> + * of_graph_is_present() - check graph's presence
> + * @node: pointer to device_node containing graph port
> + *
> + * Return: True if @node has a port or ports (with a port) sub-node,
> + * false otherwise.
> + */
> +bool of_graph_is_present(const struct device_node *node)
> +{
> +	struct device_node *ports, *port;
> +
> +	ports = of_get_child_by_name(node, "ports");
> +	if (ports)
> +		node = ports;
> +
> +	port = of_get_child_by_name(node, "port");
> +	of_node_put(ports);
> +	of_node_put(port);
> +
> +	return !!port;
> +}
> +EXPORT_SYMBOL(of_graph_is_present);
> +
>  /**
>   * of_property_count_elems_of_size - Count the number of elements in a property
>   *
> diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h
> index 01038a6aade0..4d7756087b6b 100644
> --- a/include/linux/of_graph.h
> +++ b/include/linux/of_graph.h
> @@ -38,6 +38,7 @@ struct of_endpoint {
>  	     child = of_graph_get_next_endpoint(parent, child))
>  
>  #ifdef CONFIG_OF
> +bool of_graph_is_present(const struct device_node *node);
>  int of_graph_parse_endpoint(const struct device_node *node,
>  				struct of_endpoint *endpoint);
>  int of_graph_get_endpoint_count(const struct device_node *np);
> @@ -56,6 +57,11 @@ struct device_node *of_graph_get_remote_node(const struct device_node *node,
>  					     u32 port, u32 endpoint);
>  #else
>  
> +static inline bool of_graph_is_present(const struct device_node *node)
> +{
> +	return false;
> +}
> +
>  static inline int of_graph_parse_endpoint(const struct device_node *node,
>  					struct of_endpoint *endpoint)
>  {

-- 
Regards,

Laurent Pinchart

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01  7:42 [PATCH v10 0/2] Silence missing-graph error for DRM bridges Dmitry Osipenko
2020-07-01  7:42 ` [PATCH v10 1/2] of_graph: add of_graph_is_present() Dmitry Osipenko
2020-07-01  7:55   ` Laurent Pinchart [this message]
2020-07-01  7:42 ` [PATCH v10 2/2] drm/of: Make drm_of_find_panel_or_bridge() to check graph's presence Dmitry Osipenko
2020-07-01  9:02 ` [PATCH v10 0/2] Silence missing-graph error for DRM bridges Sam Ravnborg
2020-07-01  9:31   ` Dmitry Osipenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200701075552.GJ5963@pendragon.ideasonboard.com \
    --to=laurent.pinchart@ideasonboard.com \
    --cc=devicetree@vger.kernel.org \
    --cc=digetx@gmail.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=frowand.list@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=sam@ravnborg.org \
    --cc=thierry.reding@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Devicetree Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-devicetree/0 linux-devicetree/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-devicetree linux-devicetree/ https://lore.kernel.org/linux-devicetree \
		devicetree@vger.kernel.org
	public-inbox-index linux-devicetree

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-devicetree


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git