Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
Date:   Mon, 28 Nov 2022 08:35:24 +0100
From:   Michael Walle <michael@walle.cc>
To:     =?UTF-8?Q?Rafa=C5=82_Mi=C5=82ecki?= <zajec5@gmail.com>
Cc:     Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Shawn Guo <shawnguo@kernel.org>, linux-mtd@lists.infradead.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, u-boot@lists.denx.de,
        =?UTF-8?Q?Rafa?= =?UTF-8?Q?=C5=82_Mi=C5=82ecki?= 
        <rafal@milecki.pl>
Subject: Re: [PATCH V2 1/2] nvmem: core: refactor .cell_post_process() CB
 arguments
In-Reply-To: <20221128065923.1180-1-zajec5@gmail.com>
References: <20221128065923.1180-1-zajec5@gmail.com>
User-Agent: Roundcube Webmail/1.4.13
Message-ID: <f2bb569404903bc937fbe3840582f3c4@walle.cc>
Content-Type: text/plain; charset=UTF-8;
 format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Am 2022-11-28 07:59, schrieb Rafał Miłecki:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Pass whole NVMEM cell struct and length pointer as arguments to 
> callback
> functions.
> 
> This allows:
> 
> 1. Cells content to be modified based on more info
>    Some cells (identified by their names) contain specific data that
>    needs further processing. This can be e.g. MAC address stored in an
>    ASCII format. NVMEM consumers expect MAC to be read in a binary 
> form.
>    More complex cells may be additionally described in DT. This change
>    allows also accessing relevant DT nodes and reading extra info.
> 
> 2. Adjusting data length
>    If cell processing results in reformatting it, it's required to
>    adjust length. This again applies e.g. to the MAC format change from
>    ASCII to the byte-based.
> 
> Later on we may consider more cleanups & features like:
> 1. Dropping "const char *id" and just using NVMEM cell name
> 2. Adding extra argument for cells providing multiple values
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
> This solution conflicts with 1 part of Michael's work:
> [PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
> https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/
> 
> Instead of:
> 1. Adding NVMEM cell-level post_process callback
> 2. Adding callback (.fixup_cell_info()) for setting callbacks
> 3. Dropping NVMEM device-level post_process callback
> I decided to refactor existing callback.
> 
> Michael's work on adding #nvmem-cell-cells should be possible to easily
> rebase on top of those changes.

As yours should be easily added on top of my series. I've showed that
providing a global post process hook is bad because that way you need
to have *all* cells of your device read-only.

-michael