On Wed, Feb 17, 2016 at 11:33:27AM +0900, Magnus Damm wrote: > Hi Geert, > > On Tue, Feb 16, 2016 at 10:11 PM, Geert Uytterhoeven > <geert@xxxxxxxxxxxxxx> wrote: > > On Tue, Feb 16, 2016 at 8:17 AM, Magnus Damm <magnus.damm@xxxxxxxxx> wrote: > >> From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > >> > >> Add documentation for new separate CMT0 and CMT1 DT compatible strings > >> for R-Car Gen2. These compat strings allow us to enable CMT1-specific > >> features in the driver. The old compat strings will be deprecated in > >> the not so distant future. > >> > >> Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > >> Acked-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > >> Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > >> Acked-by: Rob Herring <robh@xxxxxxxxxx> > >> --- > >> > >> Changes since V2: > >> - Added Acked-by from Rob > >> - Removed Tested-by tag from DT binding patch - duh! > >> > >> Changes since V1: > >> - Added Acked-by and Tested-by from Geert > >> - Added Acked-by from Laurent > >> > >> Documentation/devicetree/bindings/timer/renesas,cmt.txt | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> --- 0002/Documentation/devicetree/bindings/timer/renesas,cmt.txt > >> +++ work/Documentation/devicetree/bindings/timer/renesas,cmt.txt 2015-09-17 17:26:57.440513000 +0900 > >> @@ -36,6 +36,9 @@ Required Properties: > >> (CMT1 on sh73a0 and r8a7740) > >> This is a fallback for the above renesas,cmt-48-* entries. > >> > >> + - "renesas,cmt0-rcar-gen2" for 32-bit CMT0 devices included in R-Car Gen2. > >> + - "renesas,cmt1-rcar-gen2" for 48-bit CMT1 devices included in R-Car Gen2. > > > > (advancing a few months always means more comments ;-) > > Indeed! > > > I'm wondering whether we should use e.g. "renesas,rcar-gen2-cmt0" instead? > > I have no strong feelings one way or the other, but I agree that > aiming to make things more consistent must be good. FWIW, I agree with Geert's suggestion. But I also think it is not particularly important. > Your proposal makes the fallback match with what we do for a bunch > other devices on R-Car Gen2 like: > "rcar-gen2-cpg-clocks" > "rcar-gen2-scif" > But we also seem to have: > "pci-rcar-gen2" Bother, it looks like I got pci backwards :( > On R-Car Gen3 we seem to have the following per-SoC compat strings: > "dmac-r8a7795" > "etheravb-r8a7795" > "gpio-r8a7795" > "scif-r8a7795" I believe the above are to follow the existing pattern for per-SoC compat strings in the same driver, which seems sane. > But we also have: > "r8a7795-cpg-mssr" > > My only feeling is that it looks a tad odd if we follow > "<vendor>,<family-generation>-<device>" for fallback strings but > "<vendor>,<device>-<part-number>" for the per-soc binding. Why not > using the same order? Maybe this is specified in some document > somewhere? I believe that the problem is a historical one. Perhaps when we started adding bindings for our hardware there were no clear guidelines. But regardless we ended up with a mix as you describe. In the mean time guidelines have emerged and we (or at least I) have agreed with the device tree people (probably Rob) to use the <vendor>,<chip>-<device> format for new bindings. My reading is that applies even if it results in fallback and non-fallback bindings for the same driver have different orders. Some precedence for this can now be found in renesas,rcar-dmac.txt. I don't, however, think it applies where we add more soc-specific to a driver that already has such bindings. Or new fallback bindings to a driver that already has such bindings. > I guess your take with "r8a7795-cpg-mssr" above is to follow the same > order as for the fallback case? This seems sane to me, and if so then > perhaps the per-soc compat strings for the CMT should also be updated? > Same for other devices too then, like the recently added > "dmac-r8a7795"? >From my point of view it would be nice to clean things up and re-order all the bindings. But I think the drivers would need to maintain compatibility with the old strings. And I wonder if it is really worth the effort.
