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Date:   Thu, 01 Sep 2022 00:30:02 +0200
From:   Michael Walle <michael@walle.cc>
To:     Rob Herring <robh@kernel.org>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>,
        =?UTF-8?Q?Rafa=C5=82_Mi=C5=82ecki?= <rafal@milecki.pl>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Frank Rowand <frowand.list@gmail.com>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        netdev@vger.kernel.org, Ahmad Fatoum <a.fatoum@pengutronix.de>
Subject: Re: [PATCH v1 08/14] dt-bindings: mtd: relax the nvmem compatible
 string
In-Reply-To: <20220831214809.GA282739-robh@kernel.org>
References: <20220825214423.903672-1-michael@walle.cc>
 <20220825214423.903672-9-michael@walle.cc>
 <20220831214809.GA282739-robh@kernel.org>
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Am 2022-08-31 23:48, schrieb Rob Herring:
> On Thu, Aug 25, 2022 at 11:44:17PM +0200, Michael Walle wrote:
>> The "user-otp" and "factory-otp" compatible string just depicts a
>> generic NVMEM device. But an actual device tree node might as well
>> contain a more specific compatible string. Make it possible to add
>> more specific binding elsewere and just match part of the compatibles
>> here.
>> 
>> Signed-off-by: Michael Walle <michael@walle.cc>
>> ---
>>  Documentation/devicetree/bindings/mtd/mtd.yaml | 7 ++++---
>>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> In hindsight it looks like we are mixing 2 different purposes of 'which
> instance is this' and 'what is this'. 'compatible' is supposed to be 
> the
> latter.
> 
> Maybe there's a better way to handle user/factory? There's a similar
> need with partitions for A/B or factory/update.

I'm not sure I understand what you mean. It has nothing to with
user and factory provisionings.

SPI flashes have a user programmable and a factory programmable
area, some have just one of them. Whereas with A/B you (as in the
user or the board manufacturer) defines an area within a memory device
to be either slot A or slot B. But here the flash dictates what's
factory and what's user storage. It's in the datasheet.

HTH
-michael