[PATCH v4 00/20] eeprom: at24: Add OF device ID table

Geert Uytterhoeven geert at linux-m68k.org
Tue May 23 00:23:39 AEST 2017


Hi Javier,

On Mon, May 22, 2017 at 4:01 PM, Javier Martinez Canillas
<javier at dowhile0.org> wrote:
> This series is a follow-up to patch [0] that added an OF device ID table
> to the at24 EEPROM driver. As you suggested [1], this version instead of
> adding entries for every used <vendor,device> tuple, only adds a single
> entry for each chip type using the "atmel" vendor as a generic fallback.
>
> This is a re-spin that addresses some issues pointed out by Rob Herring.
>
> The first patch documents in the DT binding what's the correct vendor to
> use and what are the ones that are being deprecated. The second one adds
> the OF device ID table for the at24 driver and the next patches use this
> vendor in the compatible string to each DTS that defines a compatible I2C
> EEPROM device node.
>
> Patches can be applied independently since the DTS changes without driver
> changes are no-op and the OF table won't be used without the DTS changes.
>
> [0]: https://lkml.org/lkml/2017/3/14/589
> [1]: https://lkml.org/lkml/2017/3/15/99
>
> Best regards,
> Javier
>
> Changes in v4:
> - Document the manufacturers that have been deprecated (Rob Herring).
> - Only use the atmel manufacturer in the compatible string instead of
>   keeping the deprecated ones (Rob Herring).

I think you're referring to this (https://lkml.org/lkml/2017/4/19/1136)?

| > --- a/arch/arm/boot/dts/am335x-baltos.dtsi
| > +++ b/arch/arm/boot/dts/am335x-baltos.dtsi
| > @@ -255,7 +255,7 @@
| >     };
| >
| >     at24 at 50 {
| > -           compatible = "at24,24c02";
| > +           compatible = "at24,24c02", "atmel,24c02";
|
| I think you can just drop the at24 compatibles. A new kernel doesn't
| need it. An old kernel ignores the manufacturer. I checked that u-boot
| only matches on "atmel,*", so okay there. Don't know about the *BSDs. I
| couldn't find anything.

I think you misunderstood what Rob means.

In the case above it makes sense to drop the first compatible, as "at24" is
not a manufacturer, but refers to ATMEL's "AT24" line of i2c FLASH ROMs.

However, in cases where a real vendor/part combo is specified, like on
r8a7791-koelsch.dts:

-               compatible = "renesas,24c02";
+               compatible = "atmel,24c02";

you do want to keep the real vendor/part combo, i.e.

     compatible = "renesas,24c02", "atmel,24c02";

like in v3, which is what I gave my Reviewed-by for.

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

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


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