remoteproc: virtio: Create platform device for the remoteproc_virtio

Define a platform driver to manage the remoteproc virtio device as
a platform devices.

The platform device allows to pass rproc_vdev_data platform data to
specify properties that are stored in the rproc_vdev structure.

Such approach will allow to preserve legacy remoteproc virtio device
creation but also to probe the device using device tree mechanism.

remoteproc_virtio.c update:
  - Add rproc_virtio_driver platform driver. The probe ops replaces
    the rproc_rvdev_add_device function.
  - All reference to the rvdev->dev has been updated to rvdev-pdev->dev.
  - rproc_rvdev_release is removed as associated to the rvdev device.
  - The use of rvdev->kref counter is replaced by get/put_device on the
    remoteproc virtio platform device.
  - The vdev device no longer increments rproc device counter.
    increment/decrement is done in rproc_virtio_probe/rproc_virtio_remove
    function in charge of the vrings allocation/free.

remoteproc_core.c update:
  Migrate from the rvdev device to the rvdev platform device.
  From this patch, when a vdev resource is found in the resource table
  the remoteproc core register a platform device.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20220921135044.917140-5-arnaud.pouliquen@foss.st.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index aea79c77db0f..1abf56ad02da 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -616,9 +616,8 @@ struct rproc_vring {
 
 /**
  * struct rproc_vdev - remoteproc state for a supported virtio device
- * @refcount: reference counter for the vdev and vring allocations
  * @subdev: handle for registering the vdev as a rproc subdevice
- * @dev: device struct used for reference count semantics
+ * @pdev: remoteproc virtio platform device
  * @id: virtio device id (as in virtio_ids.h)
  * @node: list node
  * @rproc: the rproc handle
@@ -627,10 +626,9 @@ struct rproc_vring {
  * @index: vdev position versus other vdev declared in resource table
  */
 struct rproc_vdev {
-	struct kref refcount;
 
 	struct rproc_subdev subdev;
-	struct device dev;
+	struct platform_device *pdev;
 
 	unsigned int id;
 	struct list_head node;