[PATCH v3 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 at mediatek.com>
Signed-off-by: CK Hu <ck.hu at mediatek.com>
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
Signed-off-by: Bibby Hsieh <bibby.hsieh at mediatek.com>
Signed-off-by: Yongqiang Niu <yongqiang.niu at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 80 ++++++++++++++++++++++++-
 1 file changed, 77 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 9f1ff2f3f104..9340346e2727 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"
@@ -42,6 +44,9 @@ 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;
@@ -59,6 +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)
@@ -233,6 +243,47 @@ 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);
+
+	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_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);
+}
+#endif
+
 static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
 {
 	struct drm_crtc *crtc = &mtk_crtc->base;
@@ -393,7 +444,8 @@ 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;
 	}
@@ -413,7 +465,8 @@ 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;
@@ -452,6 +505,13 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
 		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
 	mutex_unlock(&mtk_crtc->hw_lock);
 }
 
@@ -528,6 +588,7 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
 	mtk_crtc->pending_planes = true;
 
 	/* Wait for planes to be disabled */
+	mtk_drm_crtc_hw_config(mtk_crtc);
 	drm_crtc_wait_one_vblank(crtc);
 
 	drm_crtc_vblank_off(crtc);
@@ -619,7 +680,7 @@ 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);
@@ -763,5 +824,18 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	priv->num_pipes++;
 	mutex_init(&mtk_crtc->hw_lock);
 
+#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;
+	}
+#endif
 	return 0;
 }
-- 
2.18.0