iommu: Add Apple DART driver
The DART is an IOMMU that is used on Apple's M1 SoC. This driver
configures the DART such that it operates in bypass mode which is
enough to support DMA for the USB3 ports integrated on the SoC.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 3e35ce8..dabc1f9 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -14,4 +14,14 @@
memory if the IOMMU has been programmed to allow access to
that memory.
+config APPLE_DART
+ bool "Apple DART support"
+ depends on IOMMU && ARCH_APPLE
+ default y
+ help
+ Enable support for the DART on Apple SoCs. The DART is Apple's
+ IOMMU implementation. The driver performs the necessary
+ configuration to put the DART into bypass mode such that it can
+ be used transparently by U-Boot.
+
endmenu