Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755387AbbBPEQK (ORCPT ); Sun, 15 Feb 2015 23:16:10 -0500 Received: from gate.crashing.org ([63.228.1.57]:46985 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752213AbbBPEQI (ORCPT ); Sun, 15 Feb 2015 23:16:08 -0500 Message-ID: <1424059156.21410.38.camel@kernel.crashing.org> Subject: [PATCH 2/2] drivers/core/of: Add symlink to device-tree from devices with an OF node From: Benjamin Herrenschmidt To: Rob Herring Cc: Grant Likely , Olof Johansson , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Arnd Bergmann Date: Mon, 16 Feb 2015 14:59:16 +1100 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.7-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2116 Lines: 62 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) properties 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 these days. This patch achieves this by adding an "of_node" symlink to devices that have a non-NULL dev->of_node pointer. Signed-off-by: Benjamin Herrenschmidt --- drivers/base/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 97e2baf..61ef574 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -469,6 +469,7 @@ static int device_add_attrs(struct device *dev) { struct class *class = dev->class; const struct device_type *type = dev->type; + struct device_node *of_node; int error; if (class) { @@ -493,6 +494,13 @@ static int device_add_attrs(struct device *dev) goto err_remove_dev_groups; } + of_node = dev_of_node(dev); + if (of_node) { + error = sysfs_create_link(&dev->kobj, &of_node->kobj, "of_node"); + if (error) + dev_warn(dev, "Error %d creating of_node link\n", error); + } + return 0; err_remove_dev_groups: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/