> However our device will have flash to store the firmware in and, whilst
> it looks as though it would be possible for us to use request_firmware
> to provide occasional firmware upgrades from userspace, I can't find any
> reference as to whether this is an accepted method for doing so. Could
> someone please confirm for me whether or not it's a good idea to use
> request_firmware for this, or perhaps point me at another standard
> method for doing firmware updates from userspace?
I think request_firmware() is fine for this... you could have a look at
drivers/net/cxgb3 to see a device that writes new firmware to flash when
it detects a version mismatch between driver and device.