From: Rob Herring <robherring2@gmail.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Olof Johansson <olof@lixom.net>,
Grant Likely <grant.likely@linaro.org>,
Greg KH <gregkh@linuxfoundation.org>,
Jeremy Kerr <jeremy.kerr@au1.ibm.com>
Subject: Re: [PATCH] drivers/core/of: Add symlink to device-tree from devices with an OF node
Date: Tue, 18 Nov 2014 10:37:08 -0600 [thread overview]
Message-ID: <CAL_Jsq+YyfMWxiOFv4x3g5hZJH0XRqCKj2He1XO9eyXWjHTMrg@mail.gmail.com> (raw)
In-Reply-To: <1415841047.5124.62.camel@kernel.crashing.org>
On Wed, Nov 12, 2014 at 7:10 PM, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
> So I've been annoyed lately with having a bunch of devices such as i2c
> eeproms (for use by VPDs, server world !) and other bits and pieces that
> I want to be able to identify from userspace, and possibly provide
> additional data about from FW.
>
> Basically, it boils down to correlating the sysfs device with the OF
> tree device node, so that user space can use device-tree info such as
> additional "location" or "label" (or whatever else we can come up with)
> propreties to identify a given device, or get some attributes of use
> about it, etc...
>
> Now, so far, we've done that in some subsystem in a fairly ad-hoc basis
> using "devspec" properties. For example, PCI creates them if it can
> correlate the probed device with a DT node. Some powerpc specific busses
> do that too.
>
> However, i2c doesn't and it would be nice to have something more generic
> since technically any device can have a corresponding device tree node.
>
> This patch adds an "of_node" symlink to devices that have a non-NULL
> dev->of_node pointer, the patch is pretty trivial and seems to work just
> fine for me.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 20da3ad..8c7b607 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -493,6 +493,15 @@ static int device_add_attrs(struct device *dev)
> goto err_remove_dev_groups;
> }
>
> +#ifdef CONFIG_OF
> + if (dev->of_node) {
if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> + error = sysfs_create_link(&dev->kobj, &dev->of_node->kobj,
> + "of_node");
> + if (error)
> + dev_warn(dev, "Error %d creating of_node link\n", error);
> + }
> +#endif /* CONFIG_OF */
> +
> return 0;
>
> err_remove_dev_groups:
>
>
next prev parent reply other threads:[~2014-11-18 16:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-07 6:33 [RFC] Add of_path property for all devices with a node Benjamin Herrenschmidt
2014-11-07 6:35 ` Benjamin Herrenschmidt
2014-11-10 5:17 ` Benjamin Herrenschmidt
2014-11-10 14:06 ` Rob Herring
2014-11-10 22:48 ` Benjamin Herrenschmidt
2014-11-13 1:10 ` [PATCH] drivers/core/of: Add symlink to device-tree from devices with an OF node Benjamin Herrenschmidt
2014-11-18 16:37 ` Rob Herring [this message]
2014-11-18 23:39 ` Jeremy Kerr
2014-11-18 23:53 ` Jeremy Kerr
2014-11-19 2:35 ` Benjamin Herrenschmidt
2014-11-19 8:38 ` Arnd Bergmann
2014-11-19 14:45 ` Rob Herring
2014-11-19 14:49 ` Arnd Bergmann
2014-11-19 15:39 ` Rob Herring
2014-11-19 16:30 ` Grant Likely
2014-11-19 2:30 ` Benjamin Herrenschmidt
2014-11-27 3:39 ` Greg KH
2014-11-27 6:24 ` Benjamin Herrenschmidt
2014-11-18 15:18 ` [RFC] Add of_path property for all devices with a node Grant Likely
2014-11-19 2:25 ` Benjamin Herrenschmidt
2015-02-18 0:25 ` [PATCH 2/2 v3] drivers/core/of: Add symlink to device-tree from devices with an OF node Benjamin Herrenschmidt
2015-02-18 1:07 ` Rob Herring
2015-02-18 4:57 ` Greg Kroah-Hartman
2015-02-18 9:50 ` Benjamin Herrenschmidt
2015-03-10 14:22 ` Rob Herring
2015-03-10 15:11 ` Greg Kroah-Hartman
2015-02-18 4:57 ` Greg Kroah-Hartman
2014-11-13 4:28 ` [RFC] Add of_path property for all devices with a node Frank Rowand
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