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Subject: Re: [RFC PATCH 0/4] mtd: core: OTP nvmem provider support
To:     Michael Walle <michael@walle.cc>, linux-mtd@lists.infradead.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Rob Herring <robh+dt@kernel.org>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>
References: <20210322181949.2805-1-michael@walle.cc>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <ace5b308-d6ea-b301-0d2e-29f95b91fe8b@linaro.org>
Date:   Tue, 30 Mar 2021 10:42:27 +0100
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Hi Michael,

On 22/03/2021 18:19, Michael Walle wrote:
> The goal is to fetch a (base) MAC address from the OTP region of a SPI NOR
> flash.
> 
> This is the first part, where I try to add the nvmem provider support to
> the MTD core.
> 
> I'm not sure about the device tree bindings. Consider the following two
> variants:
> 
> (1)
>      flash@0 {
>          ..
> 
>          otp {
>              compatible = "mtd-user-otp";
>              #address-cells = <1>;
>              #size-cells = <1>;
> 
>              serial-number@0 {
>                  reg = <0x0 0x8>;
>              };
>          };
>      };
> 
> (2)
>      flash@0 {
>          ..
> 
>          otp {
>              compatible = "mtd-user-otp";
>              #address-cells = <1>;
>              #size-cells = <1>;
> 
> 			some-useful-name {
>                  compatible = "nvmem-cells";
> 
>                  serial-number@0 {
>                      reg = <0x0 0x8>;
>                  };
> 			};
>          };
>      };
> 
> Both bindings use a subnode "opt[-N]". We cannot have the nvmem cells as
> children to the flash node because of the legacy partition binding.
> 
> (1) seems to be the form which is used almost everywhere in the kernel.
> That is, the nvmem cells are just children of the parent node.
> 
> (2) seem to be more natural, because there might also be other properties
> inside the otp subnode and might be more future-proof.
> 
> At the moment this patch implements (1).
> 


Have you looked at this series[1], are you both trying to do the same thing?

[1] 
https://lore.kernel.org/linux-mtd/20210312062830.20548-2-ansuelsmth@gmail.com/T/

--srini


> Michael Walle (4):
>    nvmem: core: allow specifying of_node
>    dt-bindings: mtd: add YAML schema for the generic MTD bindings
>    dt-bindings: mtd: add OTP bindings
>    mtd: core: add OTP nvmem provider support
> 
>   .../devicetree/bindings/mtd/common.txt        |  16 +-
>   .../devicetree/bindings/mtd/mtd.yaml          | 110 +++++++++++++
>   drivers/mtd/mtdcore.c                         | 149 ++++++++++++++++++
>   drivers/nvmem/core.c                          |   4 +-
>   include/linux/mtd/mtd.h                       |   2 +
>   include/linux/nvmem-provider.h                |   2 +
>   6 files changed, 267 insertions(+), 16 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/mtd/mtd.yaml
>