On 11/6/2014 10:33 PM, Benjamin Herrenschmidt wrote: > Hey folks ! This is not (yet) a formal patch submission but... > > 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. > > So I came up with this patch, it seems to work well for me. I'm adding > an "of_path" attribute to not conflict with the existing "devspec" one > just for the sake of this experiment (plus "devspec" sucks). Long run, > we might want to use of_path and leave a "devspec" symlink to of_path on > the few busses that currently have devspec (pci and some powerpc > specific ones). > > Comments ? > > Cheers, > Ben. If I understand correctly, that information is already available in the file uevent. For example, if I apply your patch, at least for a simple path, I see the same path name in uevent as in of_path: $ cd /sys/devices/soc/f9824900.sdhci $ cat of_path /soc/sdhci@f9824900 $ grep OF_FULLNAME uevent | cut -d"=" -f2 /soc/sdhci@f9824900 -Frank -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
