[RFC 2/2] staging: android: ion: Add of_ion_device_get function

[Moritz Fischer <moritz.fischer@ettus.com>]

Allows to obtain a reference to the global /dev/ion backing
struct ion_device via devicetree.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
---
 drivers/staging/android/ion/ion.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index e237e9f..cea264e0 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -64,6 +64,16 @@ struct ion_device {
 	struct dentry *clients_debug_root;
 };
 
+struct ion_device *of_ion_device_get(struct device_node *node)
+{
+	struct miscdevice *mdev = of_misc_get(node);
+
+	if (IS_ERR(mdev))
+		return ERR_PTR(PTR_ERR(mdev));
+
+	return container_of(mdev, struct ion_device, dev);
+}
+
 /**
  * struct ion_client - a process/hw block local address space
  * @node:		node in the tree of all clients
-- 
2.7.4