[PATCH v2 2/2] drm/imx: ipuv3-plane: support underlay plane

[Michael Tretter]

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 at pengutronix.de>
---
Changes in v2:
- Simplify and remove duplicate check for primary plane
- Rephrase commit message
---
 drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
index dfd036f3195e..f078235ed07b 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);
 

-- 
2.47.3