drm/exynos: add drm_iommu_attach_device_if_possible()

Every CRTC drivers in Exynos DRM implements the code which checks
whether IOMMU is supported or not, and if supported enable it.
Making new helper for it generalize each CRTC drivers.

Signed-off-by: Hyungwon Hwang <human.hwang@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

1 files changed, 8 insertions, 17 deletions

diff --git a/drivers/gpu/drm/exynos/exynos7_drm_decon.c b/drivers/gpu/drm/exynos/exynos7_drm_decon.c
index 2b9221cc811f..362532afd1a5 100644
--- a/drivers/gpu/drm/exynos/exynos7_drm_decon.c
+++ b/drivers/gpu/drm/exynos/exynos7_drm_decon.c
@@ -89,8 +89,9 @@ static void decon_wait_for_vblank(struct exynos_drm_crtc *crtc)
 		DRM_DEBUG_KMS("vblank wait timed out.\n");
 }
 
-static void decon_clear_channel(struct decon_context *ctx)
+static void decon_clear_channels(struct exynos_drm_crtc *crtc)
 {
+	struct decon_context *ctx = crtc->ctx;
 	unsigned int win, ch_enabled = 0;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
@@ -120,27 +121,16 @@ static int decon_ctx_initialize(struct decon_context *ctx,
 			struct drm_device *drm_dev)
 {
 	struct exynos_drm_private *priv = drm_dev->dev_private;
+	int ret;
 
 	ctx->drm_dev = drm_dev;
 	ctx->pipe = priv->pipe++;
 
-	/* attach this sub driver to iommu mapping if supported. */
-	if (is_drm_iommu_supported(ctx->drm_dev)) {
-		int ret;
-
-		/*
-		 * If any channel is already active, iommu will throw
-		 * a PAGE FAULT when enabled. So clear any channel if enabled.
-		 */
-		decon_clear_channel(ctx);
-		ret = drm_iommu_attach_device(ctx->drm_dev, ctx->dev);
-		if (ret) {
-			DRM_ERROR("drm_iommu_attach failed.\n");
-			return ret;
-		}
-	}
+	ret = drm_iommu_attach_device_if_possible(ctx->crtc, drm_dev, ctx->dev);
+	if (ret)
+		priv->pipe--;
 
-	return 0;
+	return ret;
 }
 
 static void decon_ctx_remove(struct decon_context *ctx)
@@ -633,6 +623,7 @@ static const struct exynos_drm_crtc_ops decon_crtc_ops = {
 	.wait_for_vblank = decon_wait_for_vblank,
 	.win_commit = decon_win_commit,
 	.win_disable = decon_win_disable,
+	.clear_channels = decon_clear_channels,
 };