[PATCH V3 5/5] virtio: Bind virtio device to device-tree node

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Bind the virtio devices with their of_node. This will help users of the
virtio devices to mention their dependencies on the device in the DT
itself. Like GPIO pin users can use the phandle of the device node, or
the node may contain more subnodes to add i2c or spi eeproms and other
users.

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
 drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 4b15c00c0a0a..d001e84a5b23 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -4,6 +4,7 @@
 #include <linux/virtio_config.h>
 #include <linux/module.h>
 #include <linux/idr.h>
+#include <linux/of.h>
 #include <uapi/linux/virtio_ids.h>
 
 /* Unique numbering for virtio devices. */
@@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)
 
 	/* Acknowledge the device's existence again. */
 	virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+	of_node_put(dev->dev.of_node);
+
 	return 0;
 }
 
@@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
 }
 EXPORT_SYMBOL_GPL(unregister_virtio_driver);
 
+static int virtio_device_of_init(struct virtio_device *dev)
+{
+	struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
+	char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
+	int ret, count;
+
+	if (!pnode)
+		return 0;
+
+	count = of_get_available_child_count(pnode);
+	if (!count)
+		return 0;
+
+	/* There can be only 1 child node */
+	if (WARN_ON(count > 1))
+		return -EINVAL;
+
+	np = of_get_next_available_child(pnode, NULL);
+	if (WARN_ON(!np))
+		return -ENODEV;
+
+	BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
+	       sizeof(compat));
+
+	if (!of_device_is_compatible(np, compat)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	dev->dev.of_node = np;
+	return 0;
+
+out:
+	of_node_put(np);
+	return ret;
+}
+
 /**
  * register_virtio_device - register virtio device
  * @dev        : virtio device to be registered
@@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
 	dev->index = err;
 	dev_set_name(&dev->dev, "virtio%u", dev->index);
 
+	err = virtio_device_of_init(dev);
+	if (err)
+		goto out_ida_remove;
+
 	spin_lock_init(&dev->config_lock);
 	dev->config_enabled = false;
 	dev->config_change_pending = false;
@@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
 	 */
 	err = device_add(&dev->dev);
 	if (err)
-		ida_simple_remove(&virtio_index_ida, dev->index);
+		goto out_of_node_put;
+
+	return 0;
+
+out_of_node_put:
+	of_node_put(dev->dev.of_node);
+out_ida_remove:
+	ida_simple_remove(&virtio_index_ida, dev->index);
 out:
-	if (err)
-		virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
+	virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
 	return err;
 }
 EXPORT_SYMBOL_GPL(register_virtio_device);
-- 
2.31.1.272.g89b43f80a514

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux