Re: [RFC] Add of_path property for all devices with a node

Benjamin Herrenschmidt
2014-11-07T06:35:34Z

On Fri, 2014-11-07 at 17:33 +1100, Benjamin Herrenschmidt wrote:

> So I came up with this patch,

And here is the actual patch, which might help :-) It's pretty trivial
and small...

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 20da3ad..dd0ee1b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -26,6 +26,7 @@
#include <linux/pm_runtime.h>
#include <linux/netdevice.h>
#include <linux/sysfs.h>
+#include <linux/of.h>

#include "base.h"
#include "power/power.h"
@@ -454,6 +455,23 @@ static ssize_t online_store(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RW(online);

+#ifdef CONFIG_OF
+
+static ssize_t of_path_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t s = 0;
+
+ device_lock(dev);
+ if (dev->of_node)
+ s = sprintf(buf, "%s\n", dev->of_node->full_name);
+ device_unlock(dev);
+ return s;
+}
+static DEVICE_ATTR_RO(of_path);
+
+#endif /* CONFIG_OF */
+
int device_add_groups(struct device *dev, const struct attribute_group **groups)
{
return sysfs_create_groups(&dev->kobj, groups);
@@ -487,15 +505,27 @@ static int device_add_attrs(struct device *dev)
if (error)
goto err_remove_type_groups;

+#ifdef CONFIG_OF
+ if (dev->of_node) {
+ error = device_create_file(dev, &dev_attr_of_path);
+ if (error)
+ goto err_remove_dev_groups;
+ }
+#endif /* CONFIG_OF */
+
if (device_supports_offline(dev) && !dev->offline_disabled) {
error = device_create_file(dev, &dev_attr_online);
if (error)
- goto err_remove_dev_groups;
+ goto err_remove_of_path;
}

return 0;

+ err_remove_of_path:
+#ifdef CONFIG_OF
+ device_remove_file(dev, &dev_attr_of_path);
err_remove_dev_groups:
+#endif
device_remove_groups(dev, dev->groups);
err_remove_type_groups:
if (type)