media: s5p-mfc: add iommu support

This patch adds support for IOMMU to s5p-mfc device driver. MFC firmware
is limited and it cannot use the default configuration. If IOMMU is
available, the patch disables the default DMA address space
configuration and creates a new address space of size limited to 256M
and base address set to 0x20000000.

For now the same address space is shared by both 'left' and 'right'
memory channels, because the DMA/IOMMU frameworks do not support
configuring them separately. This is not optimal, but besides limiting
total address space available has no other drawbacks (MFC firmware
supports 256M of address space per each channel).

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index fff5f4369802..6ee620ee8cd5 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -30,6 +30,7 @@
 #include "s5p_mfc_dec.h"
 #include "s5p_mfc_enc.h"
 #include "s5p_mfc_intr.h"
+#include "s5p_mfc_iommu.h"
 #include "s5p_mfc_opr.h"
 #include "s5p_mfc_cmd.h"
 #include "s5p_mfc_pm.h"
@@ -1084,6 +1085,22 @@ static int s5p_mfc_configure_dma_memory(struct s5p_mfc_dev *mfc_dev)
 	struct device *dev = &mfc_dev->plat_dev->dev;
 
 	/*
+	 * When IOMMU is available, we cannot use the default configuration,
+	 * because of MFC firmware requirements: address space limited to
+	 * 256M and non-zero default start address.
+	 * This is still simplified, not optimal configuration, but for now
+	 * IOMMU core doesn't allow to configure device's IOMMUs channel
+	 * separately.
+	 */
+	if (exynos_is_iommu_available(dev)) {
+		int ret = exynos_configure_iommu(dev, S5P_MFC_IOMMU_DMA_BASE,
+						 S5P_MFC_IOMMU_DMA_SIZE);
+		if (ret == 0)
+			mfc_dev->mem_dev_l = mfc_dev->mem_dev_r = dev;
+		return ret;
+	}
+
+	/*
 	 * Create and initialize virtual devices for accessing
 	 * reserved memory regions.
 	 */
@@ -1103,6 +1120,13 @@ static int s5p_mfc_configure_dma_memory(struct s5p_mfc_dev *mfc_dev)
 
 static void s5p_mfc_unconfigure_dma_memory(struct s5p_mfc_dev *mfc_dev)
 {
+	struct device *dev = &mfc_dev->plat_dev->dev;
+
+	if (exynos_is_iommu_available(dev)) {
+		exynos_unconfigure_iommu(dev);
+		return;
+	}
+
 	device_unregister(mfc_dev->mem_dev_l);
 	device_unregister(mfc_dev->mem_dev_r);
 }