Hi Simon, On Thu, Dec 1, 2016 at 4:18 PM, Simon Horman <horms+renesas@xxxxxxxxxxxx> wrote: > In the case of Renesas R-Car hardware we know that there are generations of > SoCs, e.g. Gen 2 and Gen 3. But beyond that its not clear what the > relationship between IP blocks might be. For example, I believe that > r8a7790 is older than r8a7791 but that doesn't imply that the latter is a > descendant of the former or vice versa. > > We can, however, by examining the documentation and behaviour of the > hardware at run-time observe that the current driver implementation appears > to be compatible with the IP blocks on SoCs within a given generation. > > For the above reasons and convenience when enabling new SoCs a > per-generation fallback compatibility string scheme being adopted for > drivers for Renesas SoCs. > > Also deprecate renesas,i2c-rcar. It seems poorly named as it is only > compatible with R-Car Gen 1. It also appears unused in mainline. > > Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 32 ++++++++++++++-------- > 1 file changed, 20 insertions(+), 12 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt > index 239632a0d709..8c679b17c4c6 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt > @@ -1,17 +1,25 @@ > I2C for R-Car platforms > > Required properties: > -- compatible: Must be one of > - "renesas,i2c-rcar" > - "renesas,i2c-r8a7778" > - "renesas,i2c-r8a7779" > - "renesas,i2c-r8a7790" > - "renesas,i2c-r8a7791" > - "renesas,i2c-r8a7792" > - "renesas,i2c-r8a7793" > - "renesas,i2c-r8a7794" > - "renesas,i2c-r8a7795" > - "renesas,i2c-r8a7796" > +- compatible: > + "renesas,i2c-r8a7778" if the device is a part of a R8A7778 SoC. > + "renesas,i2c-r8a7779" if the device is a part of a R8A7797 SoC. > + "renesas,i2c-r8a7790" if the device is a part of a R8A7790 SoC. > + "renesas,i2c-r8a7791" if the device is a part of a R8A7791 SoC. > + "renesas,i2c-r8a7792" if the device is a part of a R8A7792 SoC. > + "renesas,i2c-r8a7793" if the device is a part of a R8A7793 SoC. > + "renesas,i2c-r8a7794" if the device is a part of a R8A7794 SoC. > + "renesas,i2c-r8a7795" if the device is a part of a R8A7795 SoC. > + "renesas,i2c-r8a7796" if the device is a part of a R8A7796 SoC. > + "renesas,i2c-rcar-gen1" for a generic R-Car Gen1 compatible device. > + "renesas,i2c-rcar-gen2" for a generic R-Car Gen2 compatible device. > + "renesas,i2c-rcar-gen3" for a generic R-Car Gen3 compatible device. Please use "renesas,<family>-<module>" when adding family-specific compatible values where non are defined yet. I.e. "renesas,rcar-gen1-i2c" "renesas,rcar-gen1-i2c" "renesas,rcar-gen1-i2c" > + "renesas,i2c-rcar" (deprecated) > + > + When compatible with the generic version, nodes must list the > + SoC-specific version corresponding to the platform first followed > + by the generic version. > + > - reg: physical base address of the controller and length of memory mapped > region. > - interrupts: interrupt specifier. > @@ -33,7 +41,7 @@ Examples : > i2c0: i2c@e6508000 { > #address-cells = <1>; > #size-cells = <0>; > - compatible = "renesas,i2c-r8a7791"; > + compatible = "renesas,i2c-r8a7791", "renesas,i2c-rcar-gen2"; "renesas,rcar-gen2-i2c". Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html