On Thu, May 12, 2016 at 04:22:39PM +0000, Stuart Yoder wrote: > > > > -----Original Message----- > > From: devicetree-spec-owner@xxxxxxxxxxxxxxx [mailto:devicetree-spec-owner@xxxxxxxxxxxxxxx] On Behalf Of > > Neil Armstrong > > Sent: Thursday, May 12, 2016 2:40 AM > > To: devicetree-spec@xxxxxxxxxxxxxxx > > Subject: Node names and properties names collision > > > > Hi, > > > > I'm working on a full python device tree library to load blobs and manipulate the tree in-memory as an > > object tree (http://github.com/superna9999/pyfdt). > > My testsuite strategy was to run the DTC testsuite and load every DTC generated dtbs, re-generate a DTS > > and compare the DTC dtb-to-dts output. > > > > But I have a strange case using the Amlogic out-of-tree BSP dts where they use the same name for a sub- > > node and a property : > > > > efusekey:efusekey{ > > keynum = <4>; > > key0 = <&key0>; > > key1 = <&key1>; > > key2 = <&key2>; > > key3 = <&key3>; > > key0:key0{ > > keyname = "mac"; > > offset = <0>; > > size = <6>; > > }; > > key1:key1{ > > keyname = "mac_bt"; > > offset = <6>; > > size = <6>; > > }; > > key2:key2{ > > keyname = "mac_wifi"; > > offset = <12>; > > size = <6>; > > }; > > key3:key3{ > > keyname = "usid"; > > offset = <18>; > > size = <16>; > > }; > > }; > > > > While reading the original ePAPR and the new linaro specifications, I was not able to find an answer.... > > > > Is it authorized ? Could this be clarified in the new specifications ? > > Nodes and properties can inherently be differentiated, so there should be > no ambiguity if they happen to have the same name. Yes, it's permitted. Properties and subnodes of a node live in different logical namespaces. > That being said, in practice > I don't think this situation happens. It's rare, but it has occurred in practice. A number of old PowerMac machines had DTs with (IIRC it was both an "l2-cache" property and "l2-cache" subnode under the cpu nodes). > A device tree describes hardware. A node > name "should describe the general class of the device". Property names > should be meaninful and if they are non-standard should have a organization > specific prefix. > > The DTS example above seems to be a horrible example and follows none of those conventions. > There are no compatible strings, the node names don't seem to be describing > hardware. And not sure why you would need properties pointing to subnodes. So, > the syntax/semantics of device tree allows it, but nothing like that example would > ever pass a public review. That particular example does indeed look horrible. -- 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
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