[RFC PATCH v4 1/2] devres: Provide new helper for devm functions

[Marc Gonzalez <marc.w.gonzalez@free.fr>]

Provide a simple wrapper for devres_alloc / devres_add.

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
---
 drivers/base/devres.c  | 28 ++++++++++++++++++++++++++++
 include/linux/device.h |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 0bbb328bd17f..7fe6cc34411e 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -685,6 +685,34 @@ int devres_release_group(struct device *dev, void *id)
 }
 EXPORT_SYMBOL_GPL(devres_release_group);
 
+/**
+ * devm_add - allocate and register new device resource
+ * @dev: device to add resource to
+ * @func: resource release function
+ * @arg: resource data
+ * @size: resource data size
+ *
+ * Simple wrapper for devres_alloc / devres_add.
+ * Release the resource if the allocation fails.
+ *
+ * RETURNS:
+ * 0 if the allocation succeeds, -ENOMEM otherwise.
+ */
+int devm_add(struct device *dev, dr_release_t func, void *arg, size_t size)
+{
+	void *data = devres_alloc(func, size, GFP_KERNEL);
+
+	if (!data) {
+		func(dev, arg);
+		return -ENOMEM;
+	}
+
+	memcpy(data, arg, size);
+	devres_add(dev, data);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_add);
+
 /*
  * Custom devres actions allow inserting a simple function call
  * into the teadown sequence.
diff --git a/include/linux/device.h b/include/linux/device.h
index 0cd7c647c16c..55be3be9b276 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -247,6 +247,9 @@ void __iomem *devm_of_iomap(struct device *dev,
 			    struct device_node *node, int index,
 			    resource_size_t *size);
 
+int devm_add(struct device *dev, dr_release_t func, void *arg, size_t size);
+#define devm_vadd(dev, func, type, args...) \
+	devm_add(dev, func, &(struct type){args}, sizeof(struct type))
 /* allows to add/remove a custom action to devres stack */
 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
-- 
2.17.1