drm/sun4i: add support for Allwinner DE2 mixers

Allwinner have a new "Display Engine 2.0" in their new SoCs, which comes
with mixers to do graphic processing and feed data to TCON, like the old
backends and frontends.

Add support for the mixer on Allwinner V3s SoC; it's the simplest one.

Currently a lot of functions are still missing -- more investigations
are needed to gain enough information for them.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

6 files changed, 734 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sun4i/Kconfig b/drivers/gpu/drm/sun4i/Kconfig
index 5a8227f37cc4..978ed5032762 100644
--- a/drivers/gpu/drm/sun4i/Kconfig
+++ b/drivers/gpu/drm/sun4i/Kconfig
@@ -22,3 +22,13 @@ config DRM_SUN4I_BACKEND
 	  original Allwinner Display Engine, which has a backend to
 	  do some alpha blending and feed graphics to TCON. If M is
 	  selected the module will be called sun4i-backend.
+
+config DRM_SUN8I_MIXER
+	tristate "Support for Allwinner Display Engine 2.0 Mixer"
+	depends on DRM_SUN4I
+	default MACH_SUN8I
+	help
+	  Choose this option if you have an Allwinner SoC with the
+	  Allwinner Display Engine 2.0, which has a mixer to do some
+	  graphics mixture and feed graphics to TCON, If M is
+	  selected the module will be called sun8i-mixer.
diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
index da561d064ab8..7fce97a6f4b8 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -8,8 +8,11 @@ sun4i-tcon-y += sun4i_crtc.o
 
 sun4i-backend-y += sun4i_backend.o sun4i_layer.o
 
+sun8i-mixer-y += sun8i_mixer.o sun8i_layer.o
+
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i-drm.o sun4i-tcon.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.o
 
 obj-$(CONFIG_DRM_SUN4I_BACKEND)		+= sun4i-backend.o
+obj-$(CONFIG_DRM_SUN8I_MIXER)		+= sun8i-mixer.o
diff --git a/drivers/gpu/drm/sun4i/sun8i_layer.c b/drivers/gpu/drm/sun4i/sun8i_layer.c
new file mode 100644
index 000000000000..e627eeece658
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_layer.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) Icenowy Zheng <icenowy@aosc.io>
+ *
+ * Based on sun4i_layer.h, which is:
+ *   Copyright (C) 2015 Free Electrons
+ *   Copyright (C) 2015 NextThing Co
+ *
+ *   Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_plane_helper.h>
+#include <drm/drmP.h>
+
+#include "sun8i_layer.h"
+#include "sun8i_mixer.h"
+
+struct sun8i_plane_desc {
+	       enum drm_plane_type     type;
+	       const uint32_t          *formats;
+	       uint32_t                nformats;
+};
+
+static void sun8i_mixer_layer_atomic_disable(struct drm_plane *plane,
+					       struct drm_plane_state *old_state)
+{
+	struct sun8i_layer *layer = plane_to_sun8i_layer(plane);
+	struct sun8i_mixer *mixer = layer->mixer;
+
+	sun8i_mixer_layer_enable(mixer, layer->id, false);
+}
+
+static void sun8i_mixer_layer_atomic_update(struct drm_plane *plane,
+					      struct drm_plane_state *old_state)
+{
+	struct sun8i_layer *layer = plane_to_sun8i_layer(plane);
+	struct sun8i_mixer *mixer = layer->mixer;
+
+	sun8i_mixer_update_layer_coord(mixer, layer->id, plane);
+	sun8i_mixer_update_layer_formats(mixer, layer->id, plane);
+	sun8i_mixer_update_layer_buffer(mixer, layer->id, plane);
+	sun8i_mixer_layer_enable(mixer, layer->id, true);
+}
+
+static struct drm_plane_helper_funcs sun8i_mixer_layer_helper_funcs = {
+	.atomic_disable	= sun8i_mixer_layer_atomic_disable,
+	.atomic_update	= sun8i_mixer_layer_atomic_update,
+};
+
+static const struct drm_plane_funcs sun8i_mixer_layer_funcs = {
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
+	.destroy		= drm_plane_cleanup,
+	.disable_plane		= drm_atomic_helper_disable_plane,
+	.reset			= drm_atomic_helper_plane_reset,
+	.update_plane		= drm_atomic_helper_update_plane,
+};
+
+static const uint32_t sun8i_mixer_layer_formats[] = {
+	DRM_FORMAT_RGB888,
+	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_XRGB8888,
+};
+
+static const struct sun8i_plane_desc sun8i_mixer_planes[] = {
+	{
+		.type = DRM_PLANE_TYPE_PRIMARY,
+		.formats = sun8i_mixer_layer_formats,
+		.nformats = ARRAY_SIZE(sun8i_mixer_layer_formats),
+	},
+};
+
+static struct sun8i_layer *sun8i_layer_init_one(struct drm_device *drm,
+						struct sun8i_mixer *mixer,
+						const struct sun8i_plane_desc *plane)
+{
+	struct sun8i_layer *layer;
+	int ret;
+
+	layer = devm_kzalloc(drm->dev, sizeof(*layer), GFP_KERNEL);
+	if (!layer)
+		return ERR_PTR(-ENOMEM);
+
+	/* possible crtcs are set later */
+	ret = drm_universal_plane_init(drm, &layer->plane, 0,
+				       &sun8i_mixer_layer_funcs,
+				       plane->formats, plane->nformats,
+				       plane->type, NULL);
+	if (ret) {
+		dev_err(drm->dev, "Couldn't initialize layer\n");
+		return ERR_PTR(ret);
+	}
+
+	drm_plane_helper_add(&layer->plane,
+			     &sun8i_mixer_layer_helper_funcs);
+	layer->mixer = mixer;
+
+	return layer;
+}
+
+struct drm_plane **sun8i_layers_init(struct drm_device *drm,
+				     struct sunxi_engine *engine)
+{
+	struct drm_plane **planes;
+	struct sun8i_mixer *mixer = engine_to_sun8i_mixer(engine);
+	int i;
+
+	planes = devm_kcalloc(drm->dev, ARRAY_SIZE(sun8i_mixer_planes) + 1,
+			      sizeof(*planes), GFP_KERNEL);
+	if (!planes)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < ARRAY_SIZE(sun8i_mixer_planes); i++) {
+		const struct sun8i_plane_desc *plane = &sun8i_mixer_planes[i];
+		struct sun8i_layer *layer;
+
+		layer = sun8i_layer_init_one(drm, mixer, plane);
+		if (IS_ERR(layer)) {
+			dev_err(drm->dev, "Couldn't initialize %s plane\n",
+				i ? "overlay" : "primary");
+			return ERR_CAST(layer);
+		};
+
+		layer->id = i;
+		planes[i] = &layer->plane;
+	};
+
+	return planes;
+}
diff --git a/drivers/gpu/drm/sun4i/sun8i_layer.h b/drivers/gpu/drm/sun4i/sun8i_layer.h
new file mode 100644
index 000000000000..e5eccd27cff0
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_layer.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) Icenowy Zheng <icenowy@aosc.io>
+ *
+ * Based on sun4i_layer.h, which is:
+ *   Copyright (C) 2015 Free Electrons
+ *   Copyright (C) 2015 NextThing Co
+ *
+ *   Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#ifndef _SUN8I_LAYER_H_
+#define _SUN8I_LAYER_H_
+
+struct sunxi_engine;
+
+struct sun8i_layer {
+	struct drm_plane	plane;
+	struct sun4i_drv	*drv;
+	struct sun8i_mixer	*mixer;
+	int			id;
+};
+
+static inline struct sun8i_layer *
+plane_to_sun8i_layer(struct drm_plane *plane)
+{
+	return container_of(plane, struct sun8i_layer, plane);
+}
+
+struct drm_plane **sun8i_layers_init(struct drm_device *drm,
+				     struct sunxi_engine *engine);
+#endif /* _SUN8I_LAYER_H_ */
diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c
new file mode 100644
index 000000000000..cb193c5f1686
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
@@ -0,0 +1,414 @@
+/*
+ * Copyright (C) 2017 Icenowy Zheng <icenowy@aosc.io>
+ *
+ * Based on sun4i_backend.c, which is:
+ *   Copyright (C) 2015 Free Electrons
+ *   Copyright (C) 2015 NextThing Co
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_plane_helper.h>
+
+#include <linux/component.h>
+#include <linux/dma-mapping.h>
+#include <linux/reset.h>
+#include <linux/of_device.h>
+
+#include "sun4i_drv.h"
+#include "sun8i_mixer.h"
+#include "sun8i_layer.h"
+#include "sunxi_engine.h"
+
+static void sun8i_mixer_commit(struct sunxi_engine *engine)
+{
+	DRM_DEBUG_DRIVER("Committing changes\n");
+
+	regmap_write(engine->regs, SUN8I_MIXER_GLOBAL_DBUFF,
+		     SUN8I_MIXER_GLOBAL_DBUFF_ENABLE);
+}
+
+void sun8i_mixer_layer_enable(struct sun8i_mixer *mixer,
+				int layer, bool enable)
+{
+	u32 val;
+	/* Currently the first UI channel is used */
+	int chan = mixer->cfg->vi_num;
+
+	DRM_DEBUG_DRIVER("Enabling layer %d in channel %d\n", layer, chan);
+
+	if (enable)
+		val = SUN8I_MIXER_CHAN_UI_LAYER_ATTR_EN;
+	else
+		val = 0;
+
+	regmap_update_bits(mixer->engine.regs,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(chan, layer),
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_EN, val);
+
+	/* Set the alpha configuration */
+	regmap_update_bits(mixer->engine.regs,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(chan, layer),
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MODE_MASK,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MODE_DEF);
+	regmap_update_bits(mixer->engine.regs,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(chan, layer),
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MASK,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_DEF);
+}
+
+static int sun8i_mixer_drm_format_to_layer(struct drm_plane *plane,
+					     u32 format, u32 *mode)
+{
+	switch (format) {
+	case DRM_FORMAT_ARGB8888:
+		*mode = SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_ARGB8888;
+		break;
+
+	case DRM_FORMAT_XRGB8888:
+		*mode = SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_XRGB8888;
+		break;
+
+	case DRM_FORMAT_RGB888:
+		*mode = SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_RGB888;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int sun8i_mixer_update_layer_coord(struct sun8i_mixer *mixer,
+				     int layer, struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	/* Currently the first UI channel is used */
+	int chan = mixer->cfg->vi_num;
+
+	DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
+
+	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
+		DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
+				 state->crtc_w, state->crtc_h);
+		regmap_write(mixer->engine.regs, SUN8I_MIXER_GLOBAL_SIZE,
+			     SUN8I_MIXER_SIZE(state->crtc_w,
+					      state->crtc_h));
+		DRM_DEBUG_DRIVER("Updating blender size\n");
+		regmap_write(mixer->engine.regs,
+			     SUN8I_MIXER_BLEND_ATTR_INSIZE(0),
+			     SUN8I_MIXER_SIZE(state->crtc_w,
+					      state->crtc_h));
+		regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_OUTSIZE,
+			     SUN8I_MIXER_SIZE(state->crtc_w,
+					      state->crtc_h));
+		DRM_DEBUG_DRIVER("Updating channel size\n");
+		regmap_write(mixer->engine.regs,
+			     SUN8I_MIXER_CHAN_UI_OVL_SIZE(chan),
+			     SUN8I_MIXER_SIZE(state->crtc_w,
+					      state->crtc_h));
+	}
+
+	/* Set the line width */
+	DRM_DEBUG_DRIVER("Layer line width: %d bytes\n", fb->pitches[0]);
+	regmap_write(mixer->engine.regs,
+		     SUN8I_MIXER_CHAN_UI_LAYER_PITCH(chan, layer),
+		     fb->pitches[0]);
+
+	/* Set height and width */
+	DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
+			 state->crtc_w, state->crtc_h);
+	regmap_write(mixer->engine.regs,
+		     SUN8I_MIXER_CHAN_UI_LAYER_SIZE(chan, layer),
+		     SUN8I_MIXER_SIZE(state->crtc_w, state->crtc_h));
+
+	/* Set base coordinates */
+	DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
+			 state->crtc_x, state->crtc_y);
+	regmap_write(mixer->engine.regs,
+		     SUN8I_MIXER_CHAN_UI_LAYER_COORD(chan, layer),
+		     SUN8I_MIXER_COORD(state->crtc_x, state->crtc_y));
+
+	return 0;
+}
+
+int sun8i_mixer_update_layer_formats(struct sun8i_mixer *mixer,
+				       int layer, struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	bool interlaced = false;
+	u32 val;
+	/* Currently the first UI channel is used */
+	int chan = mixer->cfg->vi_num;
+	int ret;
+
+	if (plane->state->crtc)
+		interlaced = plane->state->crtc->state->adjusted_mode.flags
+			& DRM_MODE_FLAG_INTERLACE;
+
+	regmap_update_bits(mixer->engine.regs, SUN8I_MIXER_BLEND_OUTCTL,
+			   SUN8I_MIXER_BLEND_OUTCTL_INTERLACED,
+			   interlaced ?
+			   SUN8I_MIXER_BLEND_OUTCTL_INTERLACED : 0);
+
+	DRM_DEBUG_DRIVER("Switching display mixer interlaced mode %s\n",
+			 interlaced ? "on" : "off");
+
+	ret = sun8i_mixer_drm_format_to_layer(plane, fb->format->format,
+						&val);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Invalid format\n");
+		return ret;
+	}
+
+	regmap_update_bits(mixer->engine.regs,
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(chan, layer),
+			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_MASK, val);
+
+	return 0;
+}
+
+int sun8i_mixer_update_layer_buffer(struct sun8i_mixer *mixer,
+				      int layer, struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_gem_cma_object *gem;
+	dma_addr_t paddr;
+	/* Currently the first UI channel is used */
+	int chan = mixer->cfg->vi_num;
+	int bpp;
+
+	/* Get the physical address of the buffer in memory */
+	gem = drm_fb_cma_get_gem_obj(fb, 0);
+
+	DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->paddr);
+
+	/* Compute the start of the displayed memory */
+	bpp = fb->format->cpp[0];
+	paddr = gem->paddr + fb->offsets[0];
+
+	/* Fixup framebuffer address for src coordinates */
+	paddr += (state->src_x >> 16) * bpp;
+	paddr += (state->src_y >> 16) * fb->pitches[0];
+
+	/*
+	 * The hardware cannot correctly deal with negative crtc
+	 * coordinates, the display is cropped to the requested size,
+	 * but the display content is not moved.
+	 * Manually move the display content by fixup the framebuffer
+	 * address when crtc_x or crtc_y is negative, like what we
+	 * have did for src_x and src_y.
+	 */
+	if (state->crtc_x < 0)
+		paddr += -state->crtc_x * bpp;
+	if (state->crtc_y < 0)
+		paddr += -state->crtc_y * fb->pitches[0];
+
+	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
+
+	regmap_write(mixer->engine.regs,
+		     SUN8I_MIXER_CHAN_UI_LAYER_TOP_LADDR(chan, layer),
+		     lower_32_bits(paddr));
+
+	return 0;
+}
+
+static const struct sunxi_engine_ops sun8i_engine_ops = {
+	.commit		= sun8i_mixer_commit,
+	.layers_init	= sun8i_layers_init,
+};
+
+static struct regmap_config sun8i_mixer_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= 0xbfffc, /* guessed */
+};
+
+static int sun8i_mixer_bind(struct device *dev, struct device *master,
+			      void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct drm_device *drm = data;
+	struct sun4i_drv *drv = drm->dev_private;
+	struct sun8i_mixer *mixer;
+	struct resource *res;
+	void __iomem *regs;
+	int i, ret;
+
+	/*
+	 * The mixer uses single 32-bit register to store memory
+	 * addresses, so that it cannot deal with 64-bit memory
+	 * addresses.
+	 * Restrict the DMA mask so that the mixer won't be
+	 * allocated some memory that is too high.
+	 */
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "Cannot do 32-bit DMA.\n");
+		return ret;
+	}
+
+	mixer = devm_kzalloc(dev, sizeof(*mixer), GFP_KERNEL);
+	if (!mixer)
+		return -ENOMEM;
+	dev_set_drvdata(dev, mixer);
+	mixer->engine.ops = &sun8i_engine_ops;
+	mixer->engine.node = dev->of_node;
+	/* The ID of the mixer currently doesn't matter */
+	mixer->engine.id = -1;
+
+	mixer->cfg = of_device_get_match_data(dev);
+	if (!mixer->cfg)
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	mixer->engine.regs = devm_regmap_init_mmio(dev, regs,
+						   &sun8i_mixer_regmap_config);
+	if (IS_ERR(mixer->engine.regs)) {
+		dev_err(dev, "Couldn't create the mixer regmap\n");
+		return PTR_ERR(mixer->engine.regs);
+	}
+
+	mixer->reset = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(mixer->reset)) {
+		dev_err(dev, "Couldn't get our reset line\n");
+		return PTR_ERR(mixer->reset);
+	}
+
+	ret = reset_control_deassert(mixer->reset);
+	if (ret) {
+		dev_err(dev, "Couldn't deassert our reset line\n");
+		return ret;
+	}
+
+	mixer->bus_clk = devm_clk_get(dev, "bus");
+	if (IS_ERR(mixer->bus_clk)) {
+		dev_err(dev, "Couldn't get the mixer bus clock\n");
+		ret = PTR_ERR(mixer->bus_clk);
+		goto err_assert_reset;
+	}
+	clk_prepare_enable(mixer->bus_clk);
+
+	mixer->mod_clk = devm_clk_get(dev, "mod");
+	if (IS_ERR(mixer->mod_clk)) {
+		dev_err(dev, "Couldn't get the mixer module clock\n");
+		ret = PTR_ERR(mixer->mod_clk);
+		goto err_disable_bus_clk;
+	}
+	clk_prepare_enable(mixer->mod_clk);
+
+	list_add_tail(&mixer->engine.list, &drv->engine_list);
+
+	/* Reset the registers */
+	for (i = 0x0; i < 0x20000; i += 4)
+		regmap_write(mixer->engine.regs, i, 0);
+
+	/* Enable the mixer */
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_GLOBAL_CTL,
+		     SUN8I_MIXER_GLOBAL_CTL_RT_EN);
+
+	/* Initialize blender */
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_FCOLOR_CTL,
+		     SUN8I_MIXER_BLEND_FCOLOR_CTL_DEF);
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_PREMULTIPLY,
+		     SUN8I_MIXER_BLEND_PREMULTIPLY_DEF);
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_BKCOLOR,
+		     SUN8I_MIXER_BLEND_BKCOLOR_DEF);
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_MODE(0),
+		     SUN8I_MIXER_BLEND_MODE_DEF);
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_CK_CTL,
+		     SUN8I_MIXER_BLEND_CK_CTL_DEF);
+
+	regmap_write(mixer->engine.regs,
+		     SUN8I_MIXER_BLEND_ATTR_FCOLOR(0),
+		     SUN8I_MIXER_BLEND_ATTR_FCOLOR_DEF);
+
+	/* Select the first UI channel */
+	DRM_DEBUG_DRIVER("Selecting channel %d (first UI channel)\n",
+			 mixer->cfg->vi_num);
+	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_ROUTE,
+		     mixer->cfg->vi_num);
+
+	return 0;
+
+err_disable_bus_clk:
+	clk_disable_unprepare(mixer->bus_clk);
+err_assert_reset:
+	reset_control_assert(mixer->reset);
+	return ret;
+}
+
+static void sun8i_mixer_unbind(struct device *dev, struct device *master,
+				 void *data)
+{
+	struct sun8i_mixer *mixer = dev_get_drvdata(dev);
+
+	list_del(&mixer->engine.list);
+
+	clk_disable_unprepare(mixer->mod_clk);
+	clk_disable_unprepare(mixer->bus_clk);
+	reset_control_assert(mixer->reset);
+}
+
+static const struct component_ops sun8i_mixer_ops = {
+	.bind	= sun8i_mixer_bind,
+	.unbind	= sun8i_mixer_unbind,
+};
+
+static int sun8i_mixer_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &sun8i_mixer_ops);
+}
+
+static int sun8i_mixer_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &sun8i_mixer_ops);
+
+	return 0;
+}
+
+static const struct sun8i_mixer_cfg sun8i_v3s_mixer_cfg = {
+	.vi_num = 2,
+	.ui_num = 1,
+};
+
+static const struct of_device_id sun8i_mixer_of_table[] = {
+	{
+		.compatible = "allwinner,sun8i-v3s-de2-mixer",
+		.data = &sun8i_v3s_mixer_cfg,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sun8i_mixer_of_table);
+
+static struct platform_driver sun8i_mixer_platform_driver = {
+	.probe		= sun8i_mixer_probe,
+	.remove		= sun8i_mixer_remove,
+	.driver		= {
+		.name		= "sun8i-mixer",
+		.of_match_table	= sun8i_mixer_of_table,
+	},
+};
+module_platform_driver(sun8i_mixer_platform_driver);
+
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_DESCRIPTION("Allwinner DE2 Mixer driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.h b/drivers/gpu/drm/sun4i/sun8i_mixer.h
new file mode 100644
index 000000000000..4785ac090b8c
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2017 Icenowy Zheng <icenowy@aosc.io>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#ifndef _SUN8I_MIXER_H_
+#define _SUN8I_MIXER_H_
+
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "sunxi_engine.h"
+
+#define SUN8I_MIXER_MAX_CHAN_COUNT		4
+
+#define SUN8I_MIXER_SIZE(w, h)			(((h) - 1) << 16 | ((w) - 1))
+#define SUN8I_MIXER_COORD(x, y)			((y) << 16 | (x))
+
+#define SUN8I_MIXER_GLOBAL_CTL			0x0
+#define SUN8I_MIXER_GLOBAL_STATUS		0x4
+#define SUN8I_MIXER_GLOBAL_DBUFF		0x8
+#define SUN8I_MIXER_GLOBAL_SIZE			0xc
+
+#define SUN8I_MIXER_GLOBAL_CTL_RT_EN		0x1
+
+#define SUN8I_MIXER_GLOBAL_DBUFF_ENABLE		0x1
+
+#define SUN8I_MIXER_BLEND_FCOLOR_CTL		0x1000
+#define SUN8I_MIXER_BLEND_ATTR_FCOLOR(x)	(0x1004 + 0x10 * (x) + 0x0)
+#define SUN8I_MIXER_BLEND_ATTR_INSIZE(x)	(0x1004 + 0x10 * (x) + 0x4)
+#define SUN8I_MIXER_BLEND_ATTR_OFFSET(x)	(0x1004 + 0x10 * (x) + 0x8)
+#define SUN8I_MIXER_BLEND_ROUTE			0x1080
+#define SUN8I_MIXER_BLEND_PREMULTIPLY		0x1084
+#define SUN8I_MIXER_BLEND_BKCOLOR		0x1088
+#define SUN8I_MIXER_BLEND_OUTSIZE		0x108c
+#define SUN8I_MIXER_BLEND_MODE(x)		(0x1090 + 0x04 * (x))
+#define SUN8I_MIXER_BLEND_CK_CTL		0x10b0
+#define SUN8I_MIXER_BLEND_CK_CFG		0x10b4
+#define SUN8I_MIXER_BLEND_CK_MAX(x)		(0x10c0 + 0x04 * (x))
+#define SUN8I_MIXER_BLEND_CK_MIN(x)		(0x10e0 + 0x04 * (x))
+#define SUN8I_MIXER_BLEND_OUTCTL		0x10fc
+
+/* The following numbers are some still unknown magic numbers */
+#define SUN8I_MIXER_BLEND_ATTR_FCOLOR_DEF	0xff000000
+#define SUN8I_MIXER_BLEND_FCOLOR_CTL_DEF	0x00000101
+#define SUN8I_MIXER_BLEND_PREMULTIPLY_DEF	0x0
+#define SUN8I_MIXER_BLEND_BKCOLOR_DEF		0xff000000
+#define SUN8I_MIXER_BLEND_MODE_DEF		0x03010301
+#define SUN8I_MIXER_BLEND_CK_CTL_DEF		0x0
+
+#define SUN8I_MIXER_BLEND_OUTCTL_INTERLACED	BIT(1)
+
+/*
+ * VI channels are not used now, but the support of them may be introduced in
+ * the future.
+ */
+
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x0)
+#define SUN8I_MIXER_CHAN_UI_LAYER_SIZE(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x4)
+#define SUN8I_MIXER_CHAN_UI_LAYER_COORD(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x8)
+#define SUN8I_MIXER_CHAN_UI_LAYER_PITCH(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0xc)
+#define SUN8I_MIXER_CHAN_UI_LAYER_TOP_LADDR(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x10)
+#define SUN8I_MIXER_CHAN_UI_LAYER_BOT_LADDR(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x14)
+#define SUN8I_MIXER_CHAN_UI_LAYER_FCOLOR(ch, layer) \
+			(0x2000 + 0x1000 * (ch) + 0x20 * (layer) + 0x18)
+#define SUN8I_MIXER_CHAN_UI_TOP_HADDR(ch)	(0x2000 + 0x1000 * (ch) + 0x80)
+#define SUN8I_MIXER_CHAN_UI_BOT_HADDR(ch)	(0x2000 + 0x1000 * (ch) + 0x84)
+#define SUN8I_MIXER_CHAN_UI_OVL_SIZE(ch)	(0x2000 + 0x1000 * (ch) + 0x88)
+
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_EN		BIT(0)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MODE_MASK	GENMASK(2, 1)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_MASK	GENMASK(11, 8)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MASK	GENMASK(31, 24)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_MODE_DEF	(1 << 1)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_ARGB8888	(0 << 8)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_XRGB8888	(4 << 8)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_RGB888	(8 << 8)
+#define SUN8I_MIXER_CHAN_UI_LAYER_ATTR_ALPHA_DEF	(0xff << 24)
+
+/*
+ * These sub-engines are still unknown now, the EN registers are here only to
+ * be used to disable these sub-engines.
+ */
+#define SUN8I_MIXER_VSU_EN			0x20000
+#define SUN8I_MIXER_GSU1_EN			0x30000
+#define SUN8I_MIXER_GSU2_EN			0x40000
+#define SUN8I_MIXER_GSU3_EN			0x50000
+#define SUN8I_MIXER_FCE_EN			0xa0000
+#define SUN8I_MIXER_BWS_EN			0xa2000
+#define SUN8I_MIXER_LTI_EN			0xa4000
+#define SUN8I_MIXER_PEAK_EN			0xa6000
+#define SUN8I_MIXER_ASE_EN			0xa8000
+#define SUN8I_MIXER_FCC_EN			0xaa000
+#define SUN8I_MIXER_DCSC_EN			0xb0000
+
+struct sun8i_mixer_cfg {
+	int		vi_num;
+	int		ui_num;
+};
+
+struct sun8i_mixer {
+	struct sunxi_engine		engine;
+
+	const struct sun8i_mixer_cfg	*cfg;
+
+	struct reset_control		*reset;
+
+	struct clk			*bus_clk;
+	struct clk			*mod_clk;
+};
+
+static inline struct sun8i_mixer *
+engine_to_sun8i_mixer(struct sunxi_engine *engine)
+{
+	return container_of(engine, struct sun8i_mixer, engine);
+}
+
+void sun8i_mixer_layer_enable(struct sun8i_mixer *mixer,
+				int layer, bool enable);
+int sun8i_mixer_update_layer_coord(struct sun8i_mixer *mixer,
+				     int layer, struct drm_plane *plane);
+int sun8i_mixer_update_layer_formats(struct sun8i_mixer *mixer,
+				       int layer, struct drm_plane *plane);
+int sun8i_mixer_update_layer_buffer(struct sun8i_mixer *mixer,
+				      int layer, struct drm_plane *plane);
+#endif /* _SUN8I_MIXER_H_ */