[RFC PATCH 0/4] mtd: core: OTP nvmem provider support
Srinivas Kandagatla
srinivas.kandagatla at linaro.org
Tue Mar 30 10:42:27 BST 2021
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 at 0 {
> ..
>
> otp {
> compatible = "mtd-user-otp";
> #address-cells = <1>;
> #size-cells = <1>;
>
> serial-number at 0 {
> reg = <0x0 0x8>;
> };
> };
> };
>
> (2)
> flash at 0 {
> ..
>
> otp {
> compatible = "mtd-user-otp";
> #address-cells = <1>;
> #size-cells = <1>;
>
> some-useful-name {
> compatible = "nvmem-cells";
>
> serial-number at 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
>
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