> On 20 February 2013 19:14, Arnd Bergmann wrote: > > On Wednesday 20 February 2013, Dong Aisheng wrote: > >> On 20 February 2013 18:06, Arnd Bergmann wrote: > >> > I would first like to get an answer to the question I asked in my first mail, > >> > which is what the use case of non-DT support in this driver is. If this > >> > is used only by a new platform that has to use DT anyway, or by an existing > >> > platform that is easy enough to convert, we probably shouldn't do all this > >> > at all. > >> > > >> > >> If the platform can convert to dt, then we do not have such issue. > >> The question is do we allow the existing non-dt platforms to use it > >> before converting? > > > > I think the answer to that is "it depends". It's basically a question of > > how much work it would be to convert the platforms that need it over to > > DT, and how much of the interface it actually needs. E.g. if there is > > only one in-tree platform that needs to use syscon but can't easily be > > moved over to DT, but that platform can only have a single syscon device, > > then we don't need any of the matching support but could simply return > > the first regmap area we have in the list. > > > > Of course, if the platform in question is out of tree, I would argue > > that the whatever patches are needed by that platform should also > > remain out of tree. > > > > Basically i agree with your point. > Alexander seems to be the first non-dt user of syscon driver. > He may answer whether they could choose to convert to dt first. > But one question i wonder is that it may be hard to know how many poteintial > non-dt platforms may use syscon. OK. I can convert platform to DT, no so easy, but possible. But I will use syscon as way to using DT (and MULTIPLATFORM in the future), this mean that I should completely drop ATAG support from this platform (since I cannot use syscon device without DT support, but several platform devices need to use system-wide registers). Arnd, if its OK for you, I will use this way. (I talking about CLPS711X, you know it :) ). --- {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I