Re: [PATCH v3 0/6] Introducing Exynos ChipId driver

[Olof Johansson]

Hi,

On Sat, May 10, 2014 at 12:18 AM,  <y@xxxxxxxxxxx> wrote:
> From: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
>
> This patch series attempts to get rid of soc_is_exynosXXXX macros
> and eventually with the help of this series we can probably get
> rid of CONFIG_SOC_EXYNOSXXXX in near future.
> Each Exynos SoC has ChipID block which can give information about
> SoC's product Id and revision number. Currently we have single
> DT binding information for this as "samsung,exynos4210-chipid".
> But Exynos4 and Exynos5 SoC series have one small difference in
> chip Id, with resepect to product id bit-masks. So it means we
> should have separate compatible string for these different series
> of SoCs. So I have added second compatible string for handling
> this difference.
> This patch series is based on Kukjin Kim's for-next (3.14_rc1 tag)
> and prepared on top of following patch series and it's dependent
> patch series.
>
> [1]: Map SYSRAM through generic SRAM bindings by Sachin Kamat.
>         http://www.spinics.net/lists/arm-kernel/msg327677.html
> [2]: Exynos PMU cleanup and refactoring.
>         https://lkml.org/lkml/2014/4/30/44
> [3]: Introduce drivers/soc and add QCOM GSBI driver.
>         https://lkml.org/lkml/2014/4/24/520
>
> Revision 2 and it's discussion can be found here
>  - https://lkml.org/lkml/2014/5/6/100

As I just realized when I commented on the last patch in the patchset
(the cpufreq section): I think you can, and should, use
of_machine_is_compatible() for most of these cases, instead of using a
new API through a chipid driver. Since all boards based on an SoC
should have that in the string of compatibles, it's a shared and easy
way to handle this without adding custom drivers per manufacturer.

There will possibly be some cases where it doesn't fit well, but for
nearly all cases it should be sufficient.

(The patchset contains some other good cleanups, of course you should
keep those).


-Olof
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