diff mbox series

[V4,5/5] virtio: Bind virtio device to device-tree node

Message ID 94c12705602929968477aaf27e02439eb7a7f253.1627362340.git.viresh.kumar@linaro.org
State Accepted
Commit 694a1116b405d887c893525a6766b390989c8606
Headers show
Series virtio: Add virtio-device bindings | expand

Commit Message

Viresh Kumar July 27, 2021, 5:23 a.m. UTC 
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@arndb.de>

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 3 deletions(-)

-- 
2.31.1.272.g89b43f80a514
diff mbox series

Patch

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 4b15c00c0a0a..5f80786c2aa2 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,deviceXXXXXXXX";
+	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;
+
+	ret = snprintf(compat, sizeof(compat), "virtio,device%x", dev->id.device);
+	BUG_ON(ret >= 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);