RE: EXTERNAL: [PATCH] dt-bindings: mtd: spi-nor: deprecate Everspin MRAM devices

From: FLAVIO SULIGOI
Date: Tue Jun 04 2024 - 11:41:03 EST


Hi Michael,

...
> ---
> The referenced binding only supports the true AT25 compatible EEPROMs
> where you have to specify additional properties like size and page size
> or cypress FRAM devices where all the properties are discovered by the
> driver. I don't have the actual hardware, therefore I can't work on a
> proper driver and binding. But I really want to deprecate the use of
> these EEPROM like devices in SPI-NOR. So as a first step, mark the
> devices in the DT bindings as deprecated.
>
> There are three in-tree users of this. I hope I've CCed all the relevant
> people. With the switch to the at25 driver also comes a user-space
> facing change: there is no more MTD device. Instead there is an "eeprom"
> file in /sys now, just like for every other EEPROM.
>
> Marek already expressed, that the sps1 dts can likely be removed
> altogether. I'd like to hear from the other board DTS maintainers if
> they seem some problems moving to the EEPROM interface - or maybe that
> device isn't used at all anyway. So in the end, we can hopefully move
> all the users over to the at25 driver.

Good idea, I had already tried a similar Everspin MRAM, the EM0004LXB,
using the at25 driver, and it works fine.

> ---
> Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> index 6e3afb42926e..2dccb6b049ea 100644
> --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> @@ -21,7 +21,6 @@ properties:
> (m25p(40|80|16|32|64|128)|\
> n25q(32b|064|128a11|128a13|256a|512a|164k)))|\
> atmel,at25df(321a|641|081a)|\
> - everspin,mr25h(10|40|128|256)|\
>
> (mxicy|macronix),mx25l(4005a|1606e|6405d|8005|12805d|25635e)|\
> (mxicy|macronix),mx25u(4033|4035)|\
> (spansion,)?s25fl(128s|256s1|512s|008k|064k|164k)|\
> @@ -42,6 +41,14 @@ properties:
> - spansion,s25fs512s
> - const: jedec,spi-nor
> - const: jedec,spi-nor
> +
> + # Deprecated bindings
> + - items:
> + - pattern: "^everspin,mr25h(10|40|128|256)$"
> + - const: jedec,spi-nor
> + description:
> + Deprecated binding, use
> Documentation/devicetree/bindings/eeprom/at25.yaml.
> + deprecated: true
> description:
> SPI NOR flashes compatible with the JEDEC SFDP standard or which
> may be
> identified with the READ ID opcode (0x9F) do not deserve a
> specific
> --
> 2.39.2


Reviewed-by: Flavio Suligoi <f.suligoi@xxxxxxx>


Flavio