[PATCH 00/14] Add support for NVMEM API

Michael Walle michael at walle.cc
Tue Feb 8 17:05:58 CET 2022


Hi Sean,

Am 2022-02-08 17:02, schrieb Sean Anderson:
>>> Should this be implemented on top of/as part of syscon/regmap? In 
>>> Linux,
>>> all nvmem devices must also implement regmap support, making nvmem a
>>> subset of regmap drivers. There are certainly similarities, but I 
>>> don't
>>> know if we want to make this depend on regmap.
>> 
>> What do you mean by that? I assume with "nvmem devices" you mean the
>> nvmem providers. I've implemented the nvmem provider for MTD OTP 
>> devices
>> in linux and there is no regmap support.
> 
> According to [1],
> 
>> [The NVMEM] framework is based on regmap, so that most of the
>> abstraction available in regmap can be reused, across multiple types
>> of buses.
> 
> and
> 
>> It is mandatory that the NVMEM provider has a regmap associated with
>> its struct device. Failure to do would return error code from
>> nvmem_register().
> 
> which seems to imply that NVMEM devices should also be regmaps.

Ahh I see. That seems to be outdated, see commit
795ddd18d38f9762fbfefceab9aa16caef0cf431 ("nvmem: core: remove
regmap dependency").

-michael


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