Add MERGE engine file:
MERGE module is used to merge two slice-per-line inputs
into one side-by-side output.

Signed-off-by: jason-jh.lin <redacted>
---
 drivers/gpu/drm/mediatek/Makefile           |   1 +
 drivers/gpu/drm/mediatek/mtk_disp_drv.h     |   8 +
 drivers/gpu/drm/mediatek/mtk_disp_merge.c   | 268 ++++++++++++++++++++
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  16 ++
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   1 +
 drivers/gpu/drm/mediatek/mtk_drm_drv.c      |   2 +
 drivers/gpu/drm/mediatek/mtk_drm_drv.h      |   1 +
 7 files changed, 297 insertions(+)
 create mode 100644 drivers/gpu/drm/mediatek/mtk_disp_merge.c

diff --git a/drivers/gpu/drm/mediatek/Makefile b/drivers/gpu/drm/mediatek/Makefile
index dc54a7a69005..538e0087a44c 100644
--- a/drivers/gpu/drm/mediatek/Makefile
+++ b/drivers/gpu/drm/mediatek/Makefile

@@ -3,6 +3,7 @@
 mediatek-drm-y := mtk_disp_ccorr.o \
                  mtk_disp_color.o \
                  mtk_disp_gamma.o \
+                 mtk_disp_merge.o \
                  mtk_disp_ovl.o \
                  mtk_disp_rdma.o \
                  mtk_drm_crtc.o \

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index cafd9df2d63b..f407cd9d873e 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h

@@ -46,6 +46,14 @@ void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state);
 void mtk_gamma_start(struct device *dev);
 void mtk_gamma_stop(struct device *dev);

+int mtk_merge_clk_enable(struct device *dev);
+void mtk_merge_clk_disable(struct device *dev);
+void mtk_merge_config(struct device *dev, unsigned int width,
+                     unsigned int height, unsigned int vrefresh,
+                     unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
+void mtk_merge_start(struct device *dev);
+void mtk_merge_stop(struct device *dev);
+
 void mtk_ovl_bgclr_in_on(struct device *dev);
 void mtk_ovl_bgclr_in_off(struct device *dev);
 void mtk_ovl_bypass_shadow(struct device *dev);

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_merge.c b/drivers/gpu/drm/mediatek/mtk_disp_merge.c
new file mode 100644
index 000000000000..ebcb646bde9c
--- /dev/null
+++ b/drivers/gpu/drm/mediatek/mtk_disp_merge.c

@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 MediaTek Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/soc/mediatek/mtk-cmdq.h>
+
+#include "mtk_drm_ddp_comp.h"
+#include "mtk_drm_drv.h"
+#include "mtk_disp_drv.h"
+
+#define DISP_REG_MERGE_CTRL            0x000
+#define MERGE_EN                               1
+#define DISP_REG_MERGE_CFG_0           0x010
+#define DISP_REG_MERGE_CFG_4           0x020
+#define DISP_REG_MERGE_CFG_10          0x038
+/* no swap */
+#define SWAP_MODE                              0
+#define FLD_SWAP_MODE                          GENMASK(4, 0)
+#define DISP_REG_MERGE_CFG_12          0x040
+#define CFG_10_10_1PI_2PO_BUF_MODE             6
+#define CFG_10_10_2PI_2PO_BUF_MODE             8
+#define FLD_CFG_MERGE_MODE                     GENMASK(4, 0)
+#define DISP_REG_MERGE_CFG_24          0x070
+#define DISP_REG_MERGE_CFG_25          0x074
+#define DISP_REG_MERGE_CFG_36          0x0a0
+#define ULTRA_EN                               1