eeprom: at25: no module autoload for chip-specific compatibles

eeprom: at25: no module autoload for chip-specific compatibles

[Kryštof Černý]

Hello,

I am facing an "issue" with the at25 driver. We have the driver
compiled as a module and load a device tree overlay with

     compatible = "fujitsu,mb85rs1mt", "atmel,at25";

as required by the at25.yaml binding. However, the module is not
auto-loaded. We have to either modprobe it manually or add a modprobe
alias.

As far as I understand, the SPI core only emits
MODALIAS=spi:<first compatible without vendor prefix>, so the uevent
carries spi:mb85rs1mt. The at25 module only provides spi:at25 and
spi:fm25, added in commit 9e2cd444909b ("eeprom: at25: Add SPI ID
table"), so nothing matches. Once the module is loaded, the device
binds fine through the "atmel,at25" compatible.

Is there a better solution? I thought of adding SPI IDs for the chips
listed in the binding (mb85rs1mt, mb85rs256, ...) to
at25_spi_ids, rather than only at25 and fm25, but I do not know if
that would be acceptable upstream.

Thank you,
Kryštof Černý