[PATCH v3 1/5] drm/msm/dpu: check both DPU and MDSS devices for the IOMMU

[Dmitry Baryshkov]

Follow the lead of MDP5 driver and check both DPU and MDSS devices for
the IOMMU specifiers.

Historically DPU devices had IOMMU specified in the MDSS device tree
node, but as some of MDP5 devices are being converted to the supported
by the DPU driver, the driver should adapt and check both devices.

Reviewed-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index e23e2552e802..e8bc6d5f6ac1 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -1002,14 +1002,22 @@ static int _dpu_kms_mmu_init(struct dpu_kms *dpu_kms)
 	struct msm_mmu *mmu;
 	struct device *dpu_dev = dpu_kms->dev->dev;
 	struct device *mdss_dev = dpu_dev->parent;
+	struct device *iommu_dev;
 
 	domain = iommu_domain_alloc(&platform_bus_type);
 	if (!domain)
 		return 0;
 
-	/* IOMMUs are a part of MDSS device tree binding, not the
-	 * MDP/DPU device. */
-	mmu = msm_iommu_new(mdss_dev, domain);
+	/*
+	 * IOMMUs can be a part of MDSS device tree binding, or the
+	 * MDP/DPU device.
+	 */
+	if (dev_iommu_fwspec_get(dpu_dev))
+		iommu_dev = dpu_dev;
+	else
+		iommu_dev = mdss_dev;
+
+	mmu = msm_iommu_new(iommu_dev, domain);
 	if (IS_ERR(mmu)) {
 		iommu_domain_free(domain);
 		return PTR_ERR(mmu);
-- 
2.35.1