[2/3] software node: Introduce device_add_software_node()

Commit Message

Heikki Krogerus Aug. 25, 2020, 1:59 p.m. UTC

This helper will register a software node and then assign
it to device at the same time. The function will also make
sure that the device can't have more than one software node.

Signed-off-by: Heikki Krogerus <[e-mail]>
---
 drivers/base/swnode.c    | 45 ++++++++++++++++++++++++++++++++++++++++
 include/linux/property.h |  3 +++
 2 files changed, 48 insertions(+)

Comments

Andy Shevchenko Aug. 25, 2020, 2:32 p.m. UTC | #1

On Tue, Aug 25, 2020 at 04:59:50PM +0300, Heikki Krogerus wrote:
> This helper will register a software node and then assign
> it to device at the same time. The function will also make
> sure that the device can't have more than one software node.

> +	/* Only one software node per device. */
> +	if (dev_to_swnode(dev))
> +		return -EBUSY;

> +	swnode = dev_to_swnode(dev);
> +	if (!swnode)
> +		return;

Hmm... I didn't find implementation of dev_to_swnode().
What did I miss?

Andy Shevchenko Aug. 25, 2020, 2:33 p.m. UTC | #2

On Tue, Aug 25, 2020 at 05:32:28PM +0300, Andy Shevchenko wrote:
> On Tue, Aug 25, 2020 at 04:59:50PM +0300, Heikki Krogerus wrote:
> > This helper will register a software node and then assign
> > it to device at the same time. The function will also make
> > sure that the device can't have more than one software node.
> 
> > +	/* Only one software node per device. */
> > +	if (dev_to_swnode(dev))
> > +		return -EBUSY;
> 
> > +	swnode = dev_to_swnode(dev);
> > +	if (!swnode)
> > +		return;
> 
> Hmm... I didn't find implementation of dev_to_swnode().
> What did I miss?

Now found, I was looking into header, but it's defined in the c-file in
previous patch.

Patch

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 9a13a61a2f0bb..ec14f02565a65 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -1356,6 +1356,51 @@  void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 
+/**
+ * device_add_software_node - Assign software node to a device
+ * @dev: The device the software node is meant for.
+ * @swnode: The software node.
+ *
+ * This function will register @swnode and make it the secondary firmware node
+ * pointer of @dev. If @dev has no primary node, then @swnode will become the primary
+ * node.
+ */
+int device_add_software_node(struct device *dev, const struct software_node *swnode)
+{
+	int ret;
+
+	/* Only one software node per device. */
+	if (dev_to_swnode(dev))
+		return -EBUSY;
+
+	ret = software_node_register(swnode);
+	if (ret)
+		return ret;
+
+	set_secondary_fwnode(dev, software_node_fwnode(swnode));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_add_software_node);
+
+/**
+ * device_remove_software_node - Remove device's software node
+ * @dev: The device with the software node.
+ *
+ * This function will unregister the software node of @dev.
+ */
+void device_remove_software_node(struct device *dev)
+{
+	struct swnode *swnode;
+
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
+		return;
+
+	kobject_put(&swnode->kobj);
+}
+EXPORT_SYMBOL_GPL(device_remove_software_node);
+
 int software_node_notify(struct device *dev, unsigned long action)
 {
 	struct swnode *swnode;
diff --git a/include/linux/property.h b/include/linux/property.h
index 4a2e0edb78275..5f84286183f9a 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -468,4 +468,7 @@  fwnode_create_software_node(const struct property_entry *properties,
 			    const struct fwnode_handle *parent);
 void fwnode_remove_software_node(struct fwnode_handle *fwnode);
 
+int device_add_software_node(struct device *dev, const struct software_node *swnode);
+void device_remove_software_node(struct device *dev);
+
 #endif /* _LINUX_PROPERTY_H_ */