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

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Jason Wang <jasowang@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Rob Herring <robh+dt@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Vincent Guittot" <vincent.guittot@linaro.org>,
	"Bill Mills" <bill.mills@linaro.org>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Enrico Weigelt, metux IT consult" <info@metux.net>,
	"Jie Deng" <jie.deng@intel.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	"Arnd Bergmann" <arnd@arndb.de>,
	linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org,
	"Wolfram Sang" <wsa@kernel.org>
Subject: [PATCH V3 0/5] virtio: Add virtio-device bindings
Date: Mon, 26 Jul 2021 10:21:40 +0530	[thread overview]
Message-ID: <cover.1627273794.git.viresh.kumar@linaro.org> (raw)

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

-- 
2.31.1.272.g89b43f80a514