[PATCH v17 3/4] drm/msm/dpu: support plane splitting in quad-pipe case

[Jun Nie <jun.nie@linaro.org>]

The content of every half of screen is sent out via one interface in
dual-DSI case. The content for every interface is blended by a LM
pair in quad-pipe case, thus a LM pair should not blend any content
that cross the half of screen in this case. Clip plane into pipes per
left and right half screen ROI if topology is quad pipe case.

The clipped rectangle on every half of screen is futher handled by two
pipes if its width exceeds a limit for a single pipe.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/675416/
Link: https://lore.kernel.org/r/20250918-v6-16-rc2-quad-pipe-upstream-4-v16-9-ff6232e3472f@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c  |  11 +++
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h  |   2 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 139 +++++++++++++++++++++---------
 3 files changed, 110 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index debdbbe6160dd..87a934e3801f3 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -1606,6 +1606,17 @@ int dpu_crtc_vblank(struct drm_crtc *crtc, bool en)
 	return 0;
 }
 
+/**
+ * dpu_crtc_get_num_lm - Get mixer number in this CRTC pipeline
+ * @state: Pointer to drm crtc state object
+ */
+unsigned int dpu_crtc_get_num_lm(const struct drm_crtc_state *state)
+{
+	struct dpu_crtc_state *cstate = to_dpu_crtc_state(state);
+
+	return cstate->num_mixers;
+}
+
 #ifdef CONFIG_DEBUG_FS
 static int _dpu_debugfs_status_show(struct seq_file *s, void *data)
 {
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
index 94392b9b92454..6eaba5696e8e6 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
@@ -267,4 +267,6 @@ static inline enum dpu_crtc_client_type dpu_crtc_get_client_type(
 
 void dpu_crtc_frame_event_cb(struct drm_crtc *crtc, u32 event);
 
+unsigned int dpu_crtc_get_num_lm(const struct drm_crtc_state *state);
+
 #endif /* _DPU_CRTC_H_ */
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index 3c629f4df461d..2637abefe2602 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -881,50 +881,107 @@ static int dpu_plane_split(struct drm_plane *plane,
 	struct dpu_plane_state *pstate = to_dpu_plane_state(new_plane_state);
 	struct dpu_sw_pipe_cfg *pipe_cfg;
 	struct dpu_sw_pipe_cfg *r_pipe_cfg;
+	const struct drm_display_mode *mode = &crtc_state->adjusted_mode;
 	uint32_t max_linewidth;
+	u32 num_lm;
+	int stage_id, num_stages;
 
 	if (!new_plane_state->visible)
 		return 0;
 
-	/* move the assignment here, to ease handling to another pairs later */
-	pipe_cfg = &pstate->pipe_cfg[0];
-	r_pipe_cfg = &pstate->pipe_cfg[1];
-	/* state->src is 16.16, src_rect is not */
-	drm_rect_fp_to_int(&pipe_cfg->src_rect, &new_plane_state->src);
-
-	pipe_cfg->dst_rect = new_plane_state->dst;
+	num_lm = dpu_crtc_get_num_lm(crtc_state);
 
 	max_linewidth = pdpu->catalog->caps->max_linewidth;
 
-	drm_rect_rotate(&pipe_cfg->src_rect,
-			new_plane_state->fb->width, new_plane_state->fb->height,
-			new_plane_state->rotation);
+	/*
+	 * We have 1 mixer pair cfg for 1:1:1 and 2:2:1 topology, 2 mixer pair
+	 * configs for left and right half screen in case of 4:4:2 topology.
+	 * But we may have 2 rect to split wide plane that exceeds limit with 1
+	 * config for 2:2:1. So need to handle both wide plane splitting, and
+	 * two halves of screen splitting for quad-pipe case. Check dest
+	 * rectangle left/right clipping first, then check wide rectangle
+	 * splitting in every half next.
+	 */
+	num_stages = (num_lm + 1) / 2;
+	/* iterate mixer configs for this plane, to separate left/right with the id */
+	for (stage_id = 0; stage_id < num_stages; stage_id++) {
+		struct drm_rect mixer_rect = {
+			.x1 = stage_id * mode->hdisplay / num_stages,
+			.y1 = 0,
+			.x2 = (stage_id + 1) * mode->hdisplay / num_stages,
+			.y2 = mode->vdisplay
+			};
+		int cfg_idx = stage_id * PIPES_PER_STAGE;
+
+		pipe_cfg = &pstate->pipe_cfg[cfg_idx];
+		r_pipe_cfg = &pstate->pipe_cfg[cfg_idx + 1];
+
+		drm_rect_fp_to_int(&pipe_cfg->src_rect, &new_plane_state->src);
+
+		drm_rect_rotate(&pipe_cfg->src_rect,
+				new_plane_state->fb->width, new_plane_state->fb->height,
+				new_plane_state->rotation);
+
+		pipe_cfg->dst_rect = new_plane_state->dst;
+
+		DPU_DEBUG_PLANE(pdpu, "checking src " DRM_RECT_FMT
+				" vs clip window " DRM_RECT_FMT "\n",
+				DRM_RECT_ARG(&pipe_cfg->src_rect),
+				DRM_RECT_ARG(&mixer_rect));
+
+		/*
+		 * If this plane does not fall into mixer rect, check next
+		 * mixer rect.
+		 */
+		if (!drm_rect_clip_scaled(&pipe_cfg->src_rect,
+					  &pipe_cfg->dst_rect,
+					  &mixer_rect)) {
+			memset(pipe_cfg, 0, 2 * sizeof(struct dpu_sw_pipe_cfg));
 
-	if ((drm_rect_width(&pipe_cfg->src_rect) > max_linewidth) ||
-	     _dpu_plane_calc_clk(&crtc_state->adjusted_mode, pipe_cfg) > max_mdp_clk_rate) {
-		if (drm_rect_width(&pipe_cfg->src_rect) > 2 * max_linewidth) {
-			DPU_DEBUG_PLANE(pdpu, "invalid src " DRM_RECT_FMT " line:%u\n",
-					DRM_RECT_ARG(&pipe_cfg->src_rect), max_linewidth);
-			return -E2BIG;
+			continue;
 		}
 
-		*r_pipe_cfg = *pipe_cfg;
-		pipe_cfg->src_rect.x2 = (pipe_cfg->src_rect.x1 + pipe_cfg->src_rect.x2) >> 1;
-		pipe_cfg->dst_rect.x2 = (pipe_cfg->dst_rect.x1 + pipe_cfg->dst_rect.x2) >> 1;
-		r_pipe_cfg->src_rect.x1 = pipe_cfg->src_rect.x2;
-		r_pipe_cfg->dst_rect.x1 = pipe_cfg->dst_rect.x2;
-	} else {
-		memset(r_pipe_cfg, 0, sizeof(*r_pipe_cfg));
-	}
+		pipe_cfg->dst_rect.x1 -= mixer_rect.x1;
+		pipe_cfg->dst_rect.x2 -= mixer_rect.x1;
+
+		DPU_DEBUG_PLANE(pdpu, "Got clip src:" DRM_RECT_FMT " dst: " DRM_RECT_FMT "\n",
+				DRM_RECT_ARG(&pipe_cfg->src_rect), DRM_RECT_ARG(&pipe_cfg->dst_rect));
+
+		/* Split wide rect into 2 rect */
+		if ((drm_rect_width(&pipe_cfg->src_rect) > max_linewidth) ||
+		     _dpu_plane_calc_clk(mode, pipe_cfg) > max_mdp_clk_rate) {
+
+			if (drm_rect_width(&pipe_cfg->src_rect) > 2 * max_linewidth) {
+				DPU_DEBUG_PLANE(pdpu, "invalid src " DRM_RECT_FMT " line:%u\n",
+						DRM_RECT_ARG(&pipe_cfg->src_rect), max_linewidth);
+				return -E2BIG;
+			}
+
+			memcpy(r_pipe_cfg, pipe_cfg, sizeof(struct dpu_sw_pipe_cfg));
+			pipe_cfg->src_rect.x2 = (pipe_cfg->src_rect.x1 + pipe_cfg->src_rect.x2) >> 1;
+			pipe_cfg->dst_rect.x2 = (pipe_cfg->dst_rect.x1 + pipe_cfg->dst_rect.x2) >> 1;
+			r_pipe_cfg->src_rect.x1 = pipe_cfg->src_rect.x2;
+			r_pipe_cfg->dst_rect.x1 = pipe_cfg->dst_rect.x2;
+			DPU_DEBUG_PLANE(pdpu, "Split wide plane into:"
+					DRM_RECT_FMT " and " DRM_RECT_FMT "\n",
+					DRM_RECT_ARG(&pipe_cfg->src_rect),
+					DRM_RECT_ARG(&r_pipe_cfg->src_rect));
+		} else {
+			memset(r_pipe_cfg, 0, sizeof(struct dpu_sw_pipe_cfg));
+		}
 
-	drm_rect_rotate_inv(&pipe_cfg->src_rect,
-			    new_plane_state->fb->width, new_plane_state->fb->height,
-			    new_plane_state->rotation);
-	if (drm_rect_width(&r_pipe_cfg->src_rect) != 0)
-		drm_rect_rotate_inv(&r_pipe_cfg->src_rect,
-				    new_plane_state->fb->width, new_plane_state->fb->height,
+		drm_rect_rotate_inv(&pipe_cfg->src_rect,
+				    new_plane_state->fb->width,
+				    new_plane_state->fb->height,
 				    new_plane_state->rotation);
 
+		if (drm_rect_width(&r_pipe_cfg->src_rect) != 0)
+			drm_rect_rotate_inv(&r_pipe_cfg->src_rect,
+					    new_plane_state->fb->width,
+					    new_plane_state->fb->height,
+					    new_plane_state->rotation);
+	}
+
 	return 0;
 }
 
@@ -998,20 +1055,18 @@ static int dpu_plane_atomic_check_sspp(struct drm_plane *plane,
 		drm_atomic_get_new_plane_state(state, plane);
 	struct dpu_plane *pdpu = to_dpu_plane(plane);
 	struct dpu_plane_state *pstate = to_dpu_plane_state(new_plane_state);
-	struct dpu_sw_pipe *pipe = &pstate->pipe[0];
-	struct dpu_sw_pipe *r_pipe = &pstate->pipe[1];
-	struct dpu_sw_pipe_cfg *pipe_cfg = &pstate->pipe_cfg[0];
-	struct dpu_sw_pipe_cfg *r_pipe_cfg = &pstate->pipe_cfg[1];
-	int ret = 0;
 
-	ret = dpu_plane_atomic_check_pipe(pdpu, pipe, pipe_cfg,
-					  &crtc_state->adjusted_mode,
-					  new_plane_state);
-	if (ret)
-		return ret;
+	struct dpu_sw_pipe *pipe;
+	struct dpu_sw_pipe_cfg *pipe_cfg;
+	int ret = 0, i;
 
-	if (drm_rect_width(&r_pipe_cfg->src_rect) != 0) {
-		ret = dpu_plane_atomic_check_pipe(pdpu, r_pipe, r_pipe_cfg,
+	for (i = 0; i < PIPES_PER_PLANE; i++) {
+		pipe = &pstate->pipe[i];
+		pipe_cfg = &pstate->pipe_cfg[i];
+		if (!drm_rect_width(&pipe_cfg->src_rect))
+			continue;
+		DPU_DEBUG_PLANE(pdpu, "pipe %d is in use, validate it\n", i);
+		ret = dpu_plane_atomic_check_pipe(pdpu, pipe, pipe_cfg,
 						  &crtc_state->adjusted_mode,
 						  new_plane_state);
 		if (ret)

-- 
2.43.0