[PATCH V4 5/5] virtio: Bind virtio device to device-tree node
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2021-07-27 05:24:45
Also in:
lkml, virtualization
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
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(-)
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);
--
2.31.1.272.g89b43f80a514