When a virtio transport exposes a non-discoverable bus, the devicetree can be used to declare its child devices (if any) and/or other properties. To allow for that, the virtio framework searches for a node with a suitable compatible in virtio_device_of_init() when registering a device [1]; such compatible takes the form "virtio,deviceXX", where XX is the hexadecimal representation of the virtio device ID as defined by the virtio specification.
This patchset thus does not introduce a new functionality, but allows proper validation of nodes tied to spi-virtio devices, aligning SPI to what is already being done for e.g. I2C and GPIO virtio devices. It was sent initially as part of a different patchset [2], but since it complements a functionality that is de-facto already there and is useful beyond that specific use case it was sent separately (also following the maintainer's feedback there to separate it from remoteproc-specific changes). This was tested both with virtio-mmio using qemu-system-aarch64 and with remoteproc-virtio with a Zephyr backend (with relevant remoteproc-virtio parts still not not upstreamed - see [2]). I added myself as reviewer for the spi-virtio driver to be CC'd on any patch involving the new bindings. Thank you! Regards, Francesco [1] https://elixir.bootlin.com/linux/v7.2.8/source/drivers/virtio/virtio.c#L488 [2] https://lore.kernel.org/linux-remoteproc/[email protected]/ Signed-off-by: Francesco Valla <[email protected]> --- Changes in v2: - Expanded the commit message to better explain the functionality and the chosen compatible. - Redundant pieces dropped from bindings. - Link to v1: https://patch.msgid.link/[email protected] To: Haixu Cui <[email protected]> To: Francesco Valla <[email protected]> To: Mark Brown <[email protected]> To: Rob Herring <[email protected]> To: Krzysztof Kozlowski <[email protected]> To: Conor Dooley <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] --- Francesco Valla (2): dt-bindings: spi: add spi-virtio MAINTAINERS: add Francesco as spi-virtio reviewer .../devicetree/bindings/spi/spi-virtio.yaml | 46 ++++++++++++++++++++++ MAINTAINERS | 2 + 2 files changed, 48 insertions(+) --- base-commit: d135ab453a7400a34930bdda1ef4bdc8acfac80e change-id: 20260927-spi-virtio-bindings-f4e350b2709a Best regards, -- Francesco Valla <[email protected]>
