linux-kernel - Re: [PATCH 4/9] mtd: devices: add AT24 eeprom support

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Message-ID: <mafs0ed8byj5z.fsf@kernel.org>
Date: Tue, 02 Jul 2024 16:15:20 +0200
From: Pratyush Yadav <pratyush@...nel.org>
To: Maxime Ripard <mripard@...nel.org>
Cc: Pratyush Yadav <pratyush@...nel.org>,  Tudor Ambarus
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Subject: Re: [PATCH 4/9] mtd: devices: add AT24 eeprom support

On Tue, Jul 02 2024, Maxime Ripard wrote:

> On Tue, Jul 02, 2024 at 03:41:52PM GMT, Pratyush Yadav wrote:
>> On Mon, Jul 01 2024, Tudor Ambarus wrote:
>> 
>> > On 7/1/24 2:53 PM, Marco Felsch wrote:
>> >> EEPROMs can become quite large nowadays (>=64K). Exposing such devices
>> >> as single device isn't always sufficient. There may be partitions which
>> >> require different access permissions. Also write access always need to
>> >> to verify the offset.
>> >> 
>> >> Port the current misc/eeprom/at24.c driver to the MTD framework since
>> >> EEPROMs are memory-technology devices and the framework already supports
>> >
>> > I was under the impression that MTD devices are tightly coupled by erase
>> > blocks. But then we see MTD_NO_ERASE, so what are MTD devices after all?
>> 
>> I was curious as well so I did some digging.
>> 
[...]
>> 
>> I also found a thread from 2013 by Maxime Ripard (+Cc) suggesting adding
>> EEPROMs to MTD [1]. The main purpose would have been unifying the EEPROM
>> drivers under a single interface. I am not sure what came of it though,
>> since I can't find any patches that followed up with the proposal.
>
> That discussion led to drivers/nvmem after I started to work on
> some early prototype, and Srinivas took over that work.

So would you say it is better for EEPROM drivers to use nvmem instead of
moving under MTD?

-- 
Regards,
Pratyush Yadav