[PATCH 02/13] video: mediatek: add mixer component

The (ETHDR) mixer is one of the components of the video pipeline on
some MediaTek SoCs, such as the MT8188. Only the mixer sub-block of
the ethdr is used, which is its first register window.

Signed-off-by: Julien Stephan <[email protected]>
---
 drivers/video/mediatek/mtk_disp_mixer_mt8188.c | 76 ++++++++++++++++++++++++++
 drivers/video/mediatek/mtk_disp_mixer_mt8188.h | 16 ++++++
 2 files changed, 92 insertions(+)

diff --git a/drivers/video/mediatek/mtk_disp_mixer_mt8188.c b/drivers/video/mediatek/mtk_disp_mixer_mt8188.c
new file mode 100644
index 00000000000..60b027691ca
--- /dev/null
+++ b/drivers/video/mediatek/mtk_disp_mixer_mt8188.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Mediatek Video Disp Mixer Support
+ *
+ * Copyright (c) 2025 BayLibre, SAS.
+ * Author: Julien Stephan <[email protected]>
+ */
+
+#include <dm.h>
+
+#include "mtk_disp_comp.h"
+#include "mtk_disp_mixer_mt8188.h"
+
+#define MIX_EN			0xc
+#define MIX_ROI_SIZE		0x18
+#define MIX_DATAPATH_CON	0x1c
+#define OUTPUT_NO_RND		BIT(3)
+#define SOURCE_RGB_SEL		BIT(7)
+#define BACKGROUND_RELAY	(4 << 9)
+#define MIX_ROI_BGCLR		0x20
+#define BGCLR_BLACK		0xff000000
+#define MIX_SRC_CON		0x24
+
+#define MIX_SRC_L2_EN		BIT(2)
+#define L2_SRC_SEL		(2 << 20)
+#define L2_OUT_SEL		(2 << 22)
+
+#define MIX_FUNC_DCM0		0x120
+#define MIX_UPD_REG_CK_EN	BIT(0)
+#define MIX_FUNC_DCM1		0x124
+#define BG_CLR_CK_EN		BIT(7)
+#define MIX_CK_EN		BIT(9)
+#define MIX_FUNC_DCM_ENABLE	0xffffffff
+
+#define MIX_L2_CON		0x58
+#define NON_PREMULTI_SOURCE	(2 << 12)
+#define MIX_L2_SRC_SIZE		0x60
+
+void mtk_disp_mixer_config(struct udevice *dev, u16 width, u16 height)
+{
+	/* enable internal clocks */
+	mtk_disp_comp_write(dev, MIX_FUNC_DCM0, MIX_FUNC_DCM_ENABLE);
+	mtk_disp_comp_write(dev, MIX_FUNC_DCM1, MIX_FUNC_DCM_ENABLE);
+
+	/* enable mixer */
+	mtk_disp_comp_write(dev, MIX_EN, 0x1);
+
+	mtk_disp_comp_write(dev, MIX_ROI_SIZE, (height << 16) | width);
+	mtk_disp_comp_write(dev, MIX_DATAPATH_CON,
+			    OUTPUT_NO_RND | SOURCE_RGB_SEL);
+	mtk_disp_comp_write(dev, MIX_L2_SRC_SIZE, (height << 16) | width);
+	mtk_disp_comp_write(dev, MIX_ROI_BGCLR, BGCLR_BLACK);
+
+	/* only configure L2 since only rdma4 and rdma5 are used */
+	mtk_disp_comp_write(dev, MIX_L2_CON, NON_PREMULTI_SOURCE);
+	mtk_disp_comp_write(dev, MIX_SRC_CON,
+			    MIX_SRC_L2_EN | L2_SRC_SEL | L2_OUT_SEL);
+}
+
+static const struct udevice_id mtk_disp_mixer_ids[] = {
+	{ .compatible = "mediatek,mt8188-disp-ethdr" },
+	{}
+};
+
+/*
+ * The mixer is the first register window ("mixer" in reg-names) of the
+ * ethdr block, so binding the ethdr node with default register index 0
+ * gives the mixer registers.
+ */
+U_BOOT_DRIVER(mtk_disp_mixer) = {
+	.name	   = "mtk_disp_mixer",
+	.id	   = UCLASS_MISC,
+	.of_match  = mtk_disp_mixer_ids,
+	.probe	   = mtk_disp_comp_probe,
+	.priv_auto = sizeof(struct mtk_disp_comp_priv),
+};
diff --git a/drivers/video/mediatek/mtk_disp_mixer_mt8188.h b/drivers/video/mediatek/mtk_disp_mixer_mt8188.h
new file mode 100644
index 00000000000..a34aca6c757
--- /dev/null
+++ b/drivers/video/mediatek/mtk_disp_mixer_mt8188.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Mediatek Video Disp Mixer Support
+ *
+ * Copyright (c) 2025 BayLibre, SAS.
+ * Author: Julien Stephan <[email protected]>
+ */
+
+#ifndef _MTK_DISP_MIXER_H
+#define _MTK_DISP_MIXER_H
+
+struct udevice;
+
+void mtk_disp_mixer_config(struct udevice *dev, u16 width, u16 height);
+
+#endif

-- 
2.54.0