[PATCH v5 1/5] drm/komeda: Add side by side assembling

["james qian wang (Arm Technology China)" <james.qian.wang@arm.com>]

Komeda HW can support side by side, which splits the internal display
processing to two single halves (LEFT/RIGHT) and handle them by two
pipelines separately.
komeda "side by side" is enabled by DT property: "side_by_side_master",
once DT configured side by side, komeda need to verify it with HW's
configuration, and assemble it for the further usage.

v3: Correct a typo.

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
---
 .../gpu/drm/arm/display/komeda/komeda_crtc.c  | 13 ++++-
 .../gpu/drm/arm/display/komeda/komeda_dev.c   |  4 ++
 .../gpu/drm/arm/display/komeda/komeda_dev.h   |  9 ++++
 .../gpu/drm/arm/display/komeda/komeda_kms.h   |  3 ++
 .../drm/arm/display/komeda/komeda_pipeline.c  | 50 +++++++++++++++++--
 .../drm/arm/display/komeda/komeda_pipeline.h  |  1 +
 6 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 1c452ea75999..cee9a1692e71 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -561,21 +561,30 @@ int komeda_kms_setup_crtcs(struct komeda_kms_dev *kms,
 	kms->n_crtcs = 0;
 
 	for (i = 0; i < mdev->n_pipelines; i++) {
+		/* if sbs, one komeda_dev only can represent one CRTC */
+		if (mdev->side_by_side && i != mdev->side_by_side_master)
+			continue;
+
 		crtc = &kms->crtcs[kms->n_crtcs];
 		master = mdev->pipelines[i];
 
 		crtc->master = master;
 		crtc->slave  = komeda_pipeline_get_slave(master);
+		crtc->side_by_side = mdev->side_by_side;
 
 		if (crtc->slave)
 			sprintf(str, "pipe-%d", crtc->slave->id);
 		else
 			sprintf(str, "None");
 
-		DRM_INFO("CRTC-%d: master(pipe-%d) slave(%s).\n",
-			 kms->n_crtcs, master->id, str);
+		DRM_INFO("CRTC-%d: master(pipe-%d) slave(%s) sbs(%s).\n",
+			 kms->n_crtcs, master->id, str,
+			 crtc->side_by_side ? "On" : "Off");
 
 		kms->n_crtcs++;
+
+		if (mdev->side_by_side)
+			break;
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 4e46f650fddf..0d0e8e4ebc9d 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -178,6 +178,10 @@ static int komeda_parse_dt(struct device *dev, struct komeda_dev *mdev)
 		}
 	}
 
+	/* this DT node is experimental hence undocumented */
+	mdev->side_by_side = !of_property_read_u32(np, "side_by_side_master",
+						   &mdev->side_by_side_master);
+
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index d406a4d83352..471604b42431 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -183,6 +183,15 @@ struct komeda_dev {
 
 	/** @irq: irq number */
 	int irq;
+	/**
+	 * @side_by_side:
+	 *
+	 * on sbs the whole display frame will be split to two halves (1:2),
+	 * master pipeline handles the left part, slave for the right part
+	 */
+	bool side_by_side;
+	/** @side_by_side_master: master pipe id for side by side */
+	int side_by_side_master;
 
 	/** @lock: used to protect dpmode */
 	struct mutex lock;
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 456f3c435719..ae6654fe95e2 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -76,6 +76,9 @@ struct komeda_crtc {
 	 */
 	struct komeda_pipeline *slave;
 
+	/** @side_by_side: if the master and slave works on side by side mode */
+	bool side_by_side;
+
 	/** @slave_planes: komeda slave planes mask */
 	u32 slave_planes;
 
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
index 452e505a1fd3..104e27cc1dc3 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
@@ -326,14 +326,56 @@ static void komeda_pipeline_assemble(struct komeda_pipeline *pipe)
 struct komeda_pipeline *
 komeda_pipeline_get_slave(struct komeda_pipeline *master)
 {
-	struct komeda_component *slave;
+	struct komeda_dev *mdev = master->mdev;
+	struct komeda_component *comp, *slave;
+	u32 avail_inputs;
+
+	/* on SBS, slave pipeline merge to master via image processor */
+	if (mdev->side_by_side) {
+		comp = &master->improc->base;
+		avail_inputs = KOMEDA_PIPELINE_IMPROCS;
+	} else {
+		comp = &master->compiz->base;
+		avail_inputs = KOMEDA_PIPELINE_COMPIZS;
+	}
 
-	slave = komeda_component_pickup_input(&master->compiz->base,
-					      KOMEDA_PIPELINE_COMPIZS);
+	slave = komeda_component_pickup_input(comp, avail_inputs);
 
 	return slave ? slave->pipeline : NULL;
 }
 
+static int komeda_assemble_side_by_side(struct komeda_dev *mdev)
+{
+	struct komeda_pipeline *master, *slave;
+	int i;
+
+	if (!mdev->side_by_side)
+		return 0;
+
+	if (mdev->side_by_side_master >= mdev->n_pipelines) {
+		DRM_ERROR("DT configured side by side master-%d is invalid.\n",
+			  mdev->side_by_side_master);
+		return -EINVAL;
+	}
+
+	master = mdev->pipelines[mdev->side_by_side_master];
+	slave = komeda_pipeline_get_slave(master);
+	if (!slave || slave->n_layers != master->n_layers) {
+		DRM_ERROR("Current HW doesn't support side by side.\n");
+		return -EINVAL;
+	}
+
+	if (!master->dual_link) {
+		DRM_DEBUG_ATOMIC("SBS can not work without dual link.\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < master->n_layers; i++)
+		master->layers[i]->sbs_slave = slave->layers[i];
+
+	return 0;
+}
+
 int komeda_assemble_pipelines(struct komeda_dev *mdev)
 {
 	struct komeda_pipeline *pipe;
@@ -346,7 +388,7 @@ int komeda_assemble_pipelines(struct komeda_dev *mdev)
 		komeda_pipeline_dump(pipe);
 	}
 
-	return 0;
+	return komeda_assemble_side_by_side(mdev);
 }
 
 void komeda_pipeline_dump_register(struct komeda_pipeline *pipe,
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
index ac8725e24853..20a076cce635 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
@@ -237,6 +237,7 @@ struct komeda_layer {
 	 * not the source buffer.
 	 */
 	struct komeda_layer *right;
+	struct komeda_layer *sbs_slave;
 };
 
 struct komeda_layer_state {
-- 
2.20.1