[PATCH V3 0/5] virtio: Add virtio-device bindings

[Viresh Kumar]

Hi,

Currently the DT only provides support for following node types for virtio-mmio
nodes:

        virtio_mmio@a000000 {
                dma-coherent;
                interrupts = <0x00 0x10 0x01>;
                reg = <0x00 0xa000000 0x00 0x200>;
                compatible = "virtio,mmio";
        };

Here, each virtio-mmio corresponds to a virtio-device. But there is no way for
other users in the DT to show their dependency on virtio devices.

This patchset provides that support.

The first patch adds virtio-device bindings to allow for device sub-nodes to be
present and the second patch updates the virtio core to update the of_node.

Other patches add bindings for i2c and gpio devices.

Tested on x86 with qemu for arm64.

Pending:
- Arnd suggested that "virtio,deviceXX" may be a better compatible string, while
  I used "virtio,XX" to match what PCI and USB do currently. I didn't change it
  yet to hear Rob's view on the same before making the change, in case he has
  any preferences.

V2/2.1->V3:
- Added review-tags from Arnd and Wolfram.
- Only the 5th patch changed otherwise:
  - Use of_device_is_compatible() instead of keeping a list of devices.
  - Use snprintf (with BUG_ON on return value) to create the compatible string,
    whose length is fixed using "virtio,XXXXXXXX".
  - Use dev_of_node().

V1->V2:
- The changes (both binding and code) are made at virtio level, instead of
  virtio-mmio. This allows the same to be used by all device types, irrespective
  of the transport mechanism.

- Dropped the reg property and used compatible in the form "virtio,<DID>".

- Dropped dt-bindings/virtio/virtio_ids.h.

- Add a patch to sync virtio-ids from spec, required for the last patch.

--
Viresh

Viresh Kumar (5):
  dt-bindings: virtio: Add binding for virtio devices
  dt-bindings: i2c: Add bindings for i2c-virtio
  dt-bindings: gpio: Add bindings for gpio-virtio
  uapi: virtio_ids: Sync ids with specification
  virtio: Bind virtio device to device-tree node

 .../devicetree/bindings/gpio/gpio-virtio.yaml | 60 +++++++++++++++++++
 .../devicetree/bindings/i2c/i2c-virtio.yaml   | 51 ++++++++++++++++
 .../devicetree/bindings/virtio/mmio.yaml      |  2 +-
 .../bindings/virtio/virtio-device.yaml        | 47 +++++++++++++++
 drivers/virtio/virtio.c                       | 57 +++++++++++++++++-
 include/uapi/linux/virtio_ids.h               | 12 ++++
 6 files changed, 225 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-virtio.yaml
 create mode 100644 Documentation/devicetree/bindings/virtio/virtio-device.yaml

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2.31.1.272.g89b43f80a514