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 ff483089b26b9b4fd9746dc213f0c9a62c306ce9..c1c7be4e26c64dc53ac818d5dd77aaf543cefd37 100644 (file)
--- 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);