iommu: provide helper function to configure an IOMMU for an of master

The generic IOMMU device-tree bindings can be used to add arbitrary OF
masters to an IOMMU with a compliant binding.

This patch introduces of_iommu_configure, which does exactly that.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index 5762cdc8effe..d03abbb11c34 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -1,6 +1,7 @@
 #ifndef __OF_IOMMU_H
 #define __OF_IOMMU_H
 
+#include <linux/device.h>
 #include <linux/iommu.h>
 #include <linux/of.h>
 
@@ -11,6 +12,7 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix,
                              size_t *size);
 
 extern void of_iommu_init(void);
+extern struct iommu_ops *of_iommu_configure(struct device *dev);
 
 #else
 
@@ -22,6 +24,10 @@ static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
 }
 
 static inline void of_iommu_init(void) { }
+static inline struct iommu_ops *of_iommu_configure(struct device *dev)
+{
+        return NULL;
+}
 
 #endif  /* CONFIG_OF_IOMMU */