[PATCH 2/6] mtd: physmap_of: add a hook for Versatile write protection

[Linus Walleij]

On Sat, Feb 13, 2016 at 2:19 PM, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Tue, Jan 26, 2016 at 12:12 PM, Linus Walleij
> <linus.walleij at linaro.org> wrote:
>
>> In order to support device tree probing of Versatile NOR flash
>> chips, there must be a way to add the VPP (write protection)
>> enable/disable callback. The register in question is in the
>> system controllers of these machines. Apart from this quirk,
>> the ARM flash chips are standard CFI flash chips from various
>> vendors.
>>
>> Additionally, the Integrator/AP require you to set up the external
>> bus interface (EBI) to allow writes to the chip select where the
>> flash memory is connected.
>>
>> Solve this by looking for the arm,versatile-flash compatible
>> string in the flash device tree node. In the driver,
>> add a special hook to check for the various Versatile syscons and
>> register a callback for .set_vpp() if this compatible is present.
>>
>> Provide a special Kconfig entry for the addon hook so it will
>> not be compiled in if the Versatile boards are not supported.
>> Stubs in the header file make sure the impact will be zero on
>> other platforms. (Compilers optimze this out.)
>>
>> With this patch, a large slew of ARM board file code can be
>> removed.
>>
>> Cc: Grant Likely <grant.likely at linaro.org>
>> Cc: Rob Herring <robh at kernel.org>
>> Cc: Arnd Bergmann <arnd at arndb.de>
>> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
>
> Do you think my reply to this about reference counting and
> subsequent (accepted) patch to update the documentation
> to reflect 876fe76d793d03077
> "mtd: maps: physmap: Add reference counter to set_vpp()"
> is enough to warrant merging of this?
>
> If you want the code developed in any special direction
> just tell me.

Ping.

Yours,
Linus Walleij