[PATCH 2/4] dmaengine: sh: rcar-dmac: SMMU doesn't need IPMMU workaround

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

R-Car Gen5 doesn't use an IPMMU anymore, but a SMMU. So, the workaround
for the IPMMU becomes optional. Add a flag to distinguish. No functional
change.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/dma/sh/rcar-dmac.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index cf07c17847d0..9c5210257097 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -219,10 +219,12 @@ struct rcar_dmac {
  * struct rcar_dmac_of_data - This driver's OF data
  * @chan_offset_base: DMAC channels base offset
  * @chan_offset_stride: DMAC channels offset stride
+ * @has_ipmmu: flag telling if DMAC is connected to an IPMMU
  */
 struct rcar_dmac_of_data {
 	u32 chan_offset_base;
 	u32 chan_offset_stride;
+	unsigned int has_ipmmu:1;
 };
 
 /* -----------------------------------------------------------------------------
@@ -1877,8 +1879,9 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	 * can't use it with the IPMMU. As the IOMMU API operates at the device
 	 * level we can't disable it selectively, so ignore channel 0 for now if
 	 * the device is part of an IOMMU group.
+	 * Not applicable if system uses something else than IPMMU like SMMU.
 	 */
-	if (device_iommu_mapped(&pdev->dev))
+	if (data->has_ipmmu && device_iommu_mapped(&pdev->dev))
 		dmac->channels_mask &= ~BIT(0);
 
 	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
@@ -2000,11 +2003,13 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 static const struct rcar_dmac_of_data rcar_dmac_data = {
 	.chan_offset_base = 0x8000,
 	.chan_offset_stride = 0x80,
+	.has_ipmmu = 1,
 };
 
 static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
 	.chan_offset_base = 0x0,
 	.chan_offset_stride = 0x1000,
+	.has_ipmmu = 1,
 };
 
 static const struct of_device_id rcar_dmac_of_ids[] = {
-- 
2.47.3