drm/msm: pm runtime support for iommu

In particular, attach() and unmap() need pm-runtime get/put to ensure
iommu clks are enabled.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_iommu.c

@@ -38,14 +38,23 @@ static int msm_iommu_attach(struct msm_mmu *mmu, const char * const *names,
 			    int cnt)
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
-	return iommu_attach_device(iommu->domain, mmu->dev);
+	int ret;
+
+	pm_runtime_get_sync(mmu->dev);
+	ret = iommu_attach_device(iommu->domain, mmu->dev);
+	pm_runtime_put_sync(mmu->dev);
+
+	return ret;
 }
 
 static void msm_iommu_detach(struct msm_mmu *mmu, const char * const *names,
 			     int cnt)
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
+
+	pm_runtime_get_sync(mmu->dev);
 	iommu_detach_device(iommu->domain, mmu->dev);
+	pm_runtime_put_sync(mmu->dev);
 }
 
 static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
@@ -54,7 +63,9 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
 	size_t ret;
 
+//	pm_runtime_get_sync(mmu->dev);
 	ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
+//	pm_runtime_put_sync(mmu->dev);
 	WARN_ON(ret < 0);
 
 	return (ret == len) ? 0 : -EINVAL;
@@ -65,7 +76,9 @@ static int msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova,
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
 
+	pm_runtime_get_sync(mmu->dev);
 	iommu_unmap(iommu->domain, iova, len);
+	pm_runtime_put_sync(mmu->dev);
 
 	return 0;
 }