Re: [RFC PATCH 0/4] mtd: core: OTP nvmem provider support

[Srinivas Kandagatla]

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@xxxxxxxxx/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