On Tue, 2018-06-12 at 19:53 +0300, Andy Shevchenko wrote: > > > > It feels like a wrong approach. > > > Can OF graph help here? Would it be better approach? > > > > I don't quite understand what your objection is nor what "OF graph" > > is... > > There is no objection per se, just a doubt that this is a right thing to do. > I might be wrong, of course. > > OF graph nodes is a special API that allows you to access like you > said "different node of device-tree". > https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/graph.txt So I had a look and this is just an example on how to use phandles to link ports and endpoints... I fail to see how that relates to what this patch does. In the driver I'm doing for example, I do use a similar technique to "point" to the other node. In this case, this is a coprocessor in the SoC and I'm linking to the node that represent its interrupt controller (and its not a full fledged OS running there so we don't have a full interrupt tree for it). But once you have such a "graph", the question of mapping whatever memory resources (ie. "reg" properties) remains. Today, people will use of_address_to_resource() with ioremap, or of_iomap () to do that ... This patch just provides a devm_ variant of the latter, which also does a request_mem_resource() on it (which is missing from of_iomap), so generally is a better alternative. Cheers, Ben. -- 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
