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Subject: Re: [PATCH 1/6] dt-bindings: nvmem: add cell-type to nvmem cells
To:     Ahmad Fatoum <a.fatoum@pengutronix.de>,
        Joakim Zhang <qiangqing.zhang@nxp.com>, robh+dt@kernel.org,
        shawnguo@kernel.org,
        =?UTF-8?Q?Jan_L=c3=bcbbe?= <jlu@pengutronix.de>
Cc:     devicetree@vger.kernel.org, linux-imx@nxp.com,
        kernel@pengutronix.de, linux-kernel@vger.kernel.org
References: <20210908100257.17833-1-qiangqing.zhang@nxp.com>
 <20210908100257.17833-2-qiangqing.zhang@nxp.com>
 <6d91d833-08cc-7ce2-4fe5-3d843a8b31ae@pengutronix.de>
 <181c4037-3c34-0f71-6bb7-a9c11b173064@linaro.org>
 <dbd1c20c-e3be-6c92-52a8-2ad76d0092d0@pengutronix.de>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <8fc0a5e2-18c0-fa81-3eed-a6d596361633@linaro.org>
Date:   Wed, 22 Sep 2021 13:49:24 +0100
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On 22/09/2021 13:31, Ahmad Fatoum wrote:
>>>
>>> On 08.09.21 12:02, Joakim Zhang wrote:
>>>> From: Srinivas Kandagatla<srinivas.kandagatla@linaro.org>
>>>>
>>>> Some of the nvmem providers encode data for certain type of nvmem cell,
>>>> example mac-address is stored in ascii or with delimiter or in reverse order.
>>>>
>>>> This is much specific to vendor, so having a cell-type would allow nvmem
>>>> provider drivers to post-process this before using it.
>>> I don't agree with this assessment. Users of the OCOTP so far
>>> used this specific encoding. Bootloaders decode the OCOTP this way, but this
>>> encoding isn't really an inherent attribute of the OCOTP. A new NXP SoC
>>> with a different OTP IP will likely use the same format. Users may even
>>> use the same format on an EEPROM to populate a second off-SoC interface, .. etc.
>>>
>> That is okay.
> How would you go about using this same format on an EEPROM?

Am guessing that by the time there are more users for such formats, 
those post-processing functions should be converted into some library 
functions.

--srini

> 
>>> I'd thus prefer to not make this specific to the OCOTP as all:
>>>
>>>     * #define NVMEM_CELL_ENCODING_MAC_ADDRESS_IMX    /* ... */