From: Michael Tretter <m.tretter@pengutronix.de>
Date: Thu, 19 Feb 2026 11:32:58 +0000 (+0100)
Subject: drm/imx: ipuv3-plane: support underlay plane
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ecbcceea4767dc11881986cb41a9962cac6f6c39;p=thirdparty%2Fkernel%2Flinux.git

drm/imx: ipuv3-plane: support underlay plane

The IPUv3 overlay plane may be placed over or under the primary plane.

Set the zpos of the primary to an immutable position of 1 to have the
possibility to place the other plane underneath it.

Set the zpos of other planes (the overlay plane) to a mutable value
between 0 (the lowest possible value of a zpos) and directly above the
primary plane with the latter being the default.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patch.msgid.link/20260219-drm-imx-underlay-plane-v2-2-26ef829c5483@pengutronix.de
---

diff --git a/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
index ff483089b26b9..c1c7be4e26c64 100644
--- a/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
+++ b/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
@@ -890,7 +890,7 @@ struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 {
 	struct ipu_plane *ipu_plane;
 	const uint64_t *modifiers = ipu_format_modifiers;
-	unsigned int zpos = (type == DRM_PLANE_TYPE_PRIMARY) ? 0 : 1;
+	unsigned int primary_zpos = 1;
 	unsigned int format_count;
 	const uint32_t *formats;
 	int ret;
@@ -923,17 +923,16 @@ struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 	ipu_plane->dma = dma;
 	ipu_plane->dp_flow = dp;
 
-	if (type == DRM_PLANE_TYPE_PRIMARY)
+	if (type == DRM_PLANE_TYPE_PRIMARY) {
 		drm_plane_helper_add(&ipu_plane->base, &ipu_primary_plane_helper_funcs);
-	else
-		drm_plane_helper_add(&ipu_plane->base, &ipu_plane_helper_funcs);
-
-	if (dp == IPU_DP_FLOW_SYNC_BG || dp == IPU_DP_FLOW_SYNC_FG)
-		ret = drm_plane_create_zpos_property(&ipu_plane->base, zpos, 0,
-						     1);
-	else
 		ret = drm_plane_create_zpos_immutable_property(&ipu_plane->base,
-							       0);
+							       primary_zpos);
+	} else {
+		drm_plane_helper_add(&ipu_plane->base, &ipu_plane_helper_funcs);
+		ret = drm_plane_create_zpos_property(&ipu_plane->base,
+						     primary_zpos + 1, 0,
+						     primary_zpos + 1);
+	}
 	if (ret)
 		return ERR_PTR(ret);