An of_node can be set to a device using device_set_node(). This function cannot prevent any of_node and/or fwnode overwrites.

When adding an of_node on an already present device, the following operations need to be done: - Attach the of_node if no of_node were already attached - Attach the of_node as a fwnode if no fwnode were already attached

This is the purpose of device_add_of_node(). device_remove_of_node() reverts the operations done by device_add_of_node().

Cc: stable@vger.kernel.org Signed-off-by: Herve Codina herve.codina@bootlin.com --- drivers/base/core.c | 52 ++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 54 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c index 24c572031403..0aa63371f55d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -5118,6 +5118,58 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(set_secondary_fwnode);

+/** + * device_remove_of_node - Remove an of_node from a device + * @dev: device whose device-tree node is being removed + */ +void device_remove_of_node(struct device *dev) +{ + dev = get_device(dev); + if (!dev) + return; + + if (!dev->of_node) + goto end; + + if (dev->fwnode == of_fwnode_handle(dev->of_node)) + dev->fwnode = NULL; + + of_node_put(dev->of_node); + dev->of_node = NULL; + +end: + put_device(dev); +} +EXPORT_SYMBOL_GPL(device_remove_of_node); + +/** + * device_add_of_node - Add an of_node to an existing device + * @dev: device whose device-tree node is being added + * @of_node: of_node to add + */ +void device_add_of_node(struct device *dev, struct device_node *of_node) +{ + if (!of_node) + return; + + dev = get_device(dev); + if (!dev) + return; + + if (WARN(dev->of_node, "%s: Cannot replace node %pOF with %pOF\n", + dev_name(dev), dev->of_node, of_node)) + goto end; + + dev->of_node = of_node_get(of_node); + + if (!dev->fwnode) + dev->fwnode = of_fwnode_handle(of_node); + +end: + put_device(dev); +} +EXPORT_SYMBOL_GPL(device_add_of_node); + /** * device_set_of_node_from_dev - reuse device-tree node of another device * @dev: device whose device-tree node is being set diff --git a/include/linux/device.h b/include/linux/device.h index b4bde8d22697..e3aa25ce1f90 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1146,6 +1146,8 @@ int device_online(struct device *dev); void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode); void device_set_node(struct device *dev, struct fwnode_handle *fwnode); +void device_add_of_node(struct device *dev, struct device_node *of_node); +void device_remove_of_node(struct device *dev); void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);

static inline struct device_node *dev_of_node(struct device *dev)