[PATCH v2 02/19] driver core: platform: provide platform_device_set_of_node()

[Bartosz Golaszewski]

Encapsulate the reference counting logic for OF nodes assigned to
platform devices created with platform_device_alloc() in a helper
function. Make the kerneldoc state that this is the proper interface for
assigning OF nodes to dynamically allocated platform devices. This will
allow us to switch to counting the references of the device's firmware
nodes, not only the OF nodes.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
---
 drivers/base/platform.c         | 18 ++++++++++++++++++
 include/linux/platform_device.h |  3 +++
 2 files changed, 21 insertions(+)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index fb9120b0bcfe0e7dd9dfc0d29b91e0ad40a01440..3188d5aba5f90622f821c695049cacda030204fb 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -693,6 +693,24 @@ int platform_device_add_data(struct platform_device *pdev, const void *data,
 }
 EXPORT_SYMBOL_GPL(platform_device_add_data);
 
+/**
+ * platform_device_set_of_node - assign an OF node to device
+ * @pdev: platform device to add the node for
+ * @np: new device node
+ *
+ * Assign an OF node to this platform device. Internally keep track of the
+ * reference count. Devices created with platform_device_alloc() must use this
+ * function instead of assigning the node manually.
+ */
+void platform_device_set_of_node(struct platform_device *pdev,
+				 struct device_node *np)
+{
+	of_node_put(pdev->dev.of_node);
+	pdev->dev.of_node = of_node_get(np);
+	pdev->dev.fwnode = of_fwnode_handle(np);
+}
+EXPORT_SYMBOL_GPL(platform_device_set_of_node);
+
 /**
  * platform_device_add - add a platform device to device hierarchy
  * @pdev: platform device we're adding
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 26e6a43358e25cce2e2c38245dc0f0fc43923bf5..870d168aeff8558749eae71723e657ab150ce0be 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -19,6 +19,7 @@ struct irq_affinity;
 struct mfd_cell;
 struct property_entry;
 struct platform_device_id;
+struct device_node;
 
 struct platform_device {
 	const char	*name;
@@ -262,6 +263,8 @@ extern int platform_device_add_resources(struct platform_device *pdev,
 					 unsigned int num);
 extern int platform_device_add_data(struct platform_device *pdev,
 				    const void *data, size_t size);
+void platform_device_set_of_node(struct platform_device *pdev,
+				 struct device_node *np);
 extern int platform_device_add(struct platform_device *pdev);
 extern void platform_device_del(struct platform_device *pdev);
 extern void platform_device_put(struct platform_device *pdev);

-- 
2.47.3