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

[Linus Walleij]

On Mon, Feb 22, 2016 at 8:09 PM, Linus Walleij <linus.walleij at linaro.org> wrote:
> 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.

Ping.

Yours,
Linus Walleij