Commit db0dd9ce authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Richard Weinberger
Browse files

um: virtio_uml: Allow probing from devicetree 



Allow the virtio_uml device to be probed from the devicetree so that
sub-devices can be specified using the standard virtio bindings, for
example:

  virtio@1 {
    compatible = "virtio,uml";
    socket-path = "i2c.sock";
    virtio-device-id = <0x22>;

    i2c-controller {
      compatible = "virtio,device22";
      #address-cells = <0x01>;
      #size-cells = <0x00>;

      light-sensor@01 {
        compatible = "ti,opt3001";
        reg = <0x01>;
      };
    };
  };

Signed-off-by: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent b31297f0

arch/um/drivers/virtio_uml.c

+47 −3
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
 * Based on Virtio MMIO driver by Pawel Moll, copyright 2011-2014, ARM Ltd.

 */

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/virtio.h>
@@ -49,6 +50,7 @@ struct virtio_uml_platform_data { 
struct virtio_uml_device {

	struct virtio_device vdev;

	struct platform_device *pdev;

	struct virtio_uml_platform_data *pdata;



	spinlock_t sock_lock;

	int sock, req_fd, irq;
@@ -149,7 +151,7 @@ static int vhost_user_recv(struct virtio_uml_device *vu_dev, 
	if (rc == -ECONNRESET && vu_dev->registered) {

		struct virtio_uml_platform_data *pdata;



		pdata = vu_dev->pdev->dev.platform_data;

		pdata = vu_dev->pdata;



		virtio_break_device(&vu_dev->vdev);

		schedule_work(&pdata->conn_broken_wk);
@@ -1115,21 +1117,63 @@ void virtio_uml_set_no_vq_suspend(struct virtio_device *vdev, 
		 no_vq_suspend ? "dis" : "en");

}



static void vu_of_conn_broken(struct work_struct *wk)

{

	/*

	 * We can't remove the device from the devicetree so the only thing we

	 * can do is warn.

	 */

	WARN_ON(1);

}



/* Platform device */



static struct virtio_uml_platform_data *

virtio_uml_create_pdata(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	struct virtio_uml_platform_data *pdata;

	int ret;



	if (!np)

		return ERR_PTR(-EINVAL);



	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);

	if (!pdata)

		return ERR_PTR(-ENOMEM);



	INIT_WORK(&pdata->conn_broken_wk, vu_of_conn_broken);

	pdata->pdev = pdev;



	ret = of_property_read_string(np, "socket-path", &pdata->socket_path);

	if (ret)

		return ERR_PTR(ret);



	ret = of_property_read_u32(np, "virtio-device-id",

				   &pdata->virtio_device_id);

	if (ret)

		return ERR_PTR(ret);



	return pdata;

}



static int virtio_uml_probe(struct platform_device *pdev)

{

	struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;

	struct virtio_uml_device *vu_dev;

	int rc;



	if (!pdata)

		return -EINVAL;

	if (!pdata) {

		pdata = virtio_uml_create_pdata(pdev);

		if (IS_ERR(pdata))

			return PTR_ERR(pdata);

	}



	vu_dev = kzalloc(sizeof(*vu_dev), GFP_KERNEL);

	if (!vu_dev)

		return -ENOMEM;



	vu_dev->pdata = pdata;

	vu_dev->vdev.dev.parent = &pdev->dev;

	vu_dev->vdev.dev.release = virtio_uml_release_dev;

	vu_dev->vdev.config = &virtio_uml_config_ops;