> -----Original Message----- > From: David Gibson [mailto:david@xxxxxxxxxxxxxxxxxxxxx] > Sent: Monday, February 23, 2015 7:18 AM > To: Devshatwar, Nikhil > Cc: jdl@xxxxxxx; devicetree-compiler@xxxxxxxxxxxxxxx; linux- > omap@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2] dtc: parser: Add label while overriding nodes > > On Fri, Feb 20, 2015 at 02:11:02AM +0530, Nikhil Devshatwar wrote: > > This patch changes the dtc grammar to allow following syntax > > > > i2cexp: &i2c2 { > > ... > > }; > > > > Current device tree compiler allows to define multiple labels when > > defining the device node the first time. Typically device nodes are > > defined in DTSI files. Now these nodes can be overwritten for > updating > > some of the properties. Typically, device nodes are overridden in DTS > files. > > > > When working with adapter boards, most of the time adapter board can > > fit to multiple base boards. But depending on which base board it is > > connected to, the devices on the adapter board would be children of > different devices. > > > > e.g. On dra7-evm.dts, i2c2 is exported for expansion connector > whereas > > on dra72-evm.dts, i2c5 is exported for expansion connector. > > This causes a problem when writing a generic device tree file for the > > adapter board. Because, you cannot know whether all the devices on > > adapter board are present on i2c or i2c5. > > > > The problem can be solved by adding a common label (e.g. i2cexp) in > > both of the DTS files when overriding the device nodes for i2c2 or > i2c5. > > This way, generic adapter board file would override the i2cexp. And > > depending on which base board you use the adapter board, all the > > devices are automatically added for correct device nodes. > > > > Signed-off-by: Nikhil Devshatwar <nikhil.nd@xxxxxx> > > Applied, thanks. > OK, thanks, that's first upstream contribution! > I did tweak the testcase to use dtbs_unordered_equal instead of going > through the set of tree1 tests. > > The fact that you can only apply a single label by this method is a bit > of a wart, but it's something we can fix later. I had a look at it and > (as I suspect you already discovered) it's surprisingly complicated to > do so. Yes, but for now even one label can suffice the needs of the problem > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ > _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
