From d1c43cbc4968ef09a8c9adabc4c5ac308379ac1b Mon Sep 17 00:00:00 2001
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Thu, 16 Jun 2022 11:11:02 +0300
Subject: drm/msm/dpu: check both DPU and MDSS devices for the IOMMU
Git-commit: a07ea70a57e258289acc1bc41360c384cc53ec22
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849

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@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/489696/
Link: https://lore.kernel.org/r/20220616081106.350262-2-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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 0e938168b4ae..0509ebccbd5e 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -998,14 +998,22 @@ 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);
-- 
2.38.1