[PATCH v2 6/6] drm/mediatek: apply CMDQ control flow

[Bibby Hsieh]

Unlike other SoCs, MT8183 does not have "shadow"
registers for performaing an atomic video mode
set or page flip at vblank/vsync.

The CMDQ (Commend Queue) in MT8183 is used to help
update all relevant display controller registers
with critical time limation.

Signed-off-by: YT Shen <yt.shen@xxxxxxxxxxxx>
Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 163 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 45 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 9b2f7935ba28..7b47fe8ccee8 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -12,6 +12,8 @@
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
+#include <linux/of_address.h>
+#include <linux/soc/mediatek/mtk-cmdq.h>
 
 #include "mtk_drm_drv.h"
 #include "mtk_drm_crtc.h"
@@ -42,11 +44,17 @@ struct mtk_drm_crtc {
 	unsigned int			layer_nr;
 	bool				pending_planes;
 
+	struct cmdq_client		*cmdq_client;
+	u32				cmdq_event;
+
 	void __iomem			*config_regs;
 	const struct mtk_mmsys_reg_data *mmsys_reg_data;
 	struct mtk_disp_mutex		*mutex;
 	unsigned int			ddp_comp_nr;
 	struct mtk_ddp_comp		**ddp_comp;
+
+	/* lock for cmdq access */
+	struct mutex			chan_lock;
 };
 
 struct mtk_crtc_state {
@@ -56,6 +64,11 @@ struct mtk_crtc_state {
 	unsigned int			pending_width;
 	unsigned int			pending_height;
 	unsigned int			pending_vrefresh;
+	struct cmdq_pkt			*cmdq_handle;
+};
+
+struct mtk_cmdq_cb_data {
+	struct cmdq_pkt			*cmdq_handle;
 };
 
 static inline struct mtk_drm_crtc *to_mtk_crtc(struct drm_crtc *c)
@@ -229,6 +242,50 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 	return NULL;
 }
 
+#ifdef CONFIG_MTK_CMDQ
+static void ddp_cmdq_cb(struct cmdq_cb_data data)
+{
+	struct mtk_cmdq_cb_data *cb_data = data.data;
+
+	cmdq_pkt_destroy(cb_data->cmdq_handle);
+	kfree(cb_data);
+}
+
+static void mtk_cmdq_acquire(struct drm_crtc *crtc)
+{
+	struct mtk_crtc_state *mtk_crtc_state =
+			to_mtk_crtc_state(crtc->state);
+	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
+
+	mutex_lock(&mtk_crtc->chan_lock);
+	mtk_crtc_state->cmdq_handle =
+			cmdq_pkt_create(mtk_crtc->cmdq_client,
+					PAGE_SIZE);
+	cmdq_pkt_clear_event(mtk_crtc_state->cmdq_handle,
+			     mtk_crtc->cmdq_event);
+	cmdq_pkt_wfe(mtk_crtc_state->cmdq_handle, mtk_crtc->cmdq_event);
+}
+
+static void mtk_cmdq_release(struct drm_crtc *crtc)
+{
+	struct mtk_crtc_state *mtk_crtc_state =
+			to_mtk_crtc_state(crtc->state);
+	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
+	struct mtk_cmdq_cb_data *cb_data;
+
+	cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
+	if (!cb_data) {
+		DRM_DEV_ERROR(crtc->dev->dev, "Failed to alloc cb_data\n");
+		return;
+	}
+
+	cb_data->cmdq_handle = mtk_crtc_state->cmdq_handle;
+	cmdq_pkt_flush_async(mtk_crtc_state->cmdq_handle,
+			     ddp_cmdq_cb, cb_data);
+	mutex_unlock(&mtk_crtc->chan_lock);
+}
+#endif
+
 static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
 {
 	struct drm_crtc *crtc = &mtk_crtc->base;
@@ -383,7 +440,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
 	if (state->pending_config) {
 		mtk_ddp_comp_config(comp, state->pending_width,
 				    state->pending_height,
-				    state->pending_vrefresh, 0, NULL);
+				    state->pending_vrefresh, 0,
+				    state->cmdq_handle);
 
 		state->pending_config = false;
 	}
@@ -403,13 +461,54 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
 
 			if (comp)
 				mtk_ddp_comp_layer_config(comp, local_layer,
-							  plane_state, NULL);
+							  plane_state,
+							  state->cmdq_handle);
 			plane_state->pending.config = false;
 		}
 		mtk_crtc->pending_planes = false;
 	}
 }
 
+static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
+{
+	struct drm_crtc *crtc = &mtk_crtc->base;
+	struct mtk_drm_private *priv = crtc->dev->dev_private;
+	unsigned int pending_planes = 0;
+	int i;
+
+	for (i = 0; i < mtk_crtc->layer_nr; i++) {
+		struct drm_plane *plane = &mtk_crtc->planes[i];
+		struct mtk_plane_state *plane_state;
+
+		plane_state = to_mtk_plane_state(plane->state);
+		if (plane_state->pending.dirty) {
+			plane_state->pending.config = true;
+			plane_state->pending.dirty = false;
+			pending_planes |= BIT(i);
+		} else if (plane_state->pending.async_dirty) {
+			plane_state->pending.config = true;
+			plane_state->pending.async_update = false;
+			plane_state->pending.async_dirty = false;
+			pending_planes |= BIT(i);
+		}
+	}
+	if (pending_planes)
+		mtk_crtc->pending_planes = true;
+
+	if (priv->data->shadow_register) {
+		mtk_disp_mutex_acquire(mtk_crtc->mutex);
+		mtk_crtc_ddp_config(crtc);
+		mtk_disp_mutex_release(mtk_crtc->mutex);
+	}
+#ifdef CONFIG_MTK_CMDQ
+	if (mtk_crtc->cmdq_client) {
+		mtk_cmdq_acquire(crtc);
+		mtk_crtc_ddp_config(crtc);
+		mtk_cmdq_release(crtc);
+	}
+#endif
+}
+
 int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane,
 			     struct mtk_plane_state *state)
 {
@@ -425,34 +524,15 @@ int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane,
 void mtk_drm_crtc_async_update(struct drm_crtc *crtc, struct drm_plane *plane,
 			       struct drm_plane_state *new_state)
 {
-	struct mtk_drm_private *priv = crtc->dev->dev_private;
 	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
 	const struct drm_plane_helper_funcs *plane_helper_funcs =
 			plane->helper_private;
-	int i;
 
 	if (!mtk_crtc->enabled)
 		return;
 
 	plane_helper_funcs->atomic_update(plane, new_state);
-
-	for (i = 0; i < mtk_crtc->layer_nr; i++) {
-		struct drm_plane *plane = &mtk_crtc->planes[i];
-		struct mtk_plane_state *plane_state;
-
-		plane_state = to_mtk_plane_state(plane->state);
-		if (plane_state->pending.async_dirty) {
-			plane_state->pending.config = true;
-			plane_state->pending.async_update = false;
-			plane_state->pending.async_dirty = false;
-		}
-	}
-	mtk_crtc->pending_planes = true;
-	if (priv->data->shadow_register) {
-		mtk_disp_mutex_acquire(mtk_crtc->mutex);
-		mtk_crtc_ddp_config(crtc);
-		mtk_disp_mutex_release(mtk_crtc->mutex);
-	}
+	mtk_drm_crtc_hw_config(mtk_crtc);
 }
 
 static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
@@ -536,34 +616,14 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
 				      struct drm_crtc_state *old_crtc_state)
 {
 	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
-	struct mtk_drm_private *priv = crtc->dev->dev_private;
-	unsigned int pending_planes = 0;
 	int i;
 
 	if (mtk_crtc->event)
 		mtk_crtc->pending_needs_vblank = true;
-	for (i = 0; i < mtk_crtc->layer_nr; i++) {
-		struct drm_plane *plane = &mtk_crtc->planes[i];
-		struct mtk_plane_state *plane_state;
-
-		plane_state = to_mtk_plane_state(plane->state);
-		if (plane_state->pending.dirty) {
-			plane_state->pending.config = true;
-			plane_state->pending.dirty = false;
-			pending_planes |= BIT(i);
-		}
-	}
-	if (pending_planes)
-		mtk_crtc->pending_planes = true;
 	if (crtc->state->color_mgmt_changed)
 		for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
 			mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
-
-	if (priv->data->shadow_register) {
-		mtk_disp_mutex_acquire(mtk_crtc->mutex);
-		mtk_crtc_ddp_config(crtc);
-		mtk_disp_mutex_release(mtk_crtc->mutex);
-	}
+	mtk_drm_crtc_hw_config(mtk_crtc);
 }
 
 static const struct drm_crtc_funcs mtk_crtc_funcs = {
@@ -613,7 +673,7 @@ void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *comp)
 	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
 	struct mtk_drm_private *priv = crtc->dev->dev_private;
 
-	if (!priv->data->shadow_register)
+	if (!priv->data->shadow_register && !mtk_crtc->cmdq_client)
 		mtk_crtc_ddp_config(crtc);
 
 	mtk_drm_finish_page_flip(mtk_crtc);
@@ -755,6 +815,19 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
 	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, MTK_LUT_SIZE);
 	priv->num_pipes++;
-
+#ifdef CONFIG_MTK_CMDQ
+	mtk_crtc->cmdq_client =
+			cmdq_mbox_create(dev, drm_crtc_index(&mtk_crtc->base),
+					 2000);
+	of_property_read_u32_index(dev->of_node, "mediatek,gce-events",
+				   drm_crtc_index(&mtk_crtc->base),
+				   &mtk_crtc->cmdq_event);
+	if (IS_ERR(mtk_crtc->cmdq_client)) {
+		dev_dbg(dev, "mtk_crtc %d failed to create mailbox client, writing register by CPU now\n",
+			drm_crtc_index(&mtk_crtc->base));
+		mtk_crtc->cmdq_client = NULL;
+	}
+	mutex_init(&mtk_crtc->chan_lock);
+#endif
 	return 0;
 }
-- 
2.18.0