Re: [PATCH v4 06/11] drm/sun4i: add support for Allwinner DE2 mixers

[Icenowy Zheng]

ä 2017å4æ18æ GMT+08:00 äå5:00:47, Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> åå:
>On Sun, Apr 16, 2017 at 08:08:44PM +0800, Icenowy Zheng wrote:
>> 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@xxxxxxx>
>> ---
>> Changes in v4:
>> - Killed some dead code according to Jernej.
>> 
>>  drivers/gpu/drm/sun4i/Kconfig       |  10 +
>>  drivers/gpu/drm/sun4i/Makefile      |   4 +
>>  drivers/gpu/drm/sun4i/sun8i_layer.c | 142 ++++++++++++++
>>  drivers/gpu/drm/sun4i/sun8i_layer.h |  36 ++++
>>  drivers/gpu/drm/sun4i/sun8i_mixer.c | 381
>++++++++++++++++++++++++++++++++++++
>>  drivers/gpu/drm/sun4i/sun8i_mixer.h | 131 +++++++++++++
>>  6 files changed, 704 insertions(+)
>>  create mode 100644 drivers/gpu/drm/sun4i/sun8i_layer.c
>>  create mode 100644 drivers/gpu/drm/sun4i/sun8i_layer.h
>>  create mode 100644 drivers/gpu/drm/sun4i/sun8i_mixer.c
>>  create mode 100644 drivers/gpu/drm/sun4i/sun8i_mixer.h
>> 
>> diff --git a/drivers/gpu/drm/sun4i/Kconfig
>b/drivers/gpu/drm/sun4i/Kconfig
>> index 5a8227f37cc4..15557484520d 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_SUN4I_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 1db1068b9be1..7625c2dad1bb 100644
>> --- a/drivers/gpu/drm/sun4i/Makefile
>> +++ b/drivers/gpu/drm/sun4i/Makefile
>> @@ -9,7 +9,11 @@ sun4i-tcon-y += sun4i_crtc.o
>>  sun4i-backend-y += sun4i_layer.o
>>  sun4i-backend-y += sun4i_backend.o
>>  
>> +sun8i-mixer-y += sun8i_layer.o
>> +sun8i-mixer-y += sun8i_mixer.o
>> +
>>  obj-$(CONFIG_DRM_SUN4I)		+= sun4i-drm.o sun4i-tcon.o
>>  obj-$(CONFIG_DRM_SUN4I_BACKEND)	+= sun4i-backend.o
>> +obj-$(CONFIG_DRM_SUN4I_SUN8I_MIXER) += sun8i-mixer.o
>
>Please align the value using tabs.

Should I re-align existed items?

>
>>  obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
>>  obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.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..d70a90d963b0
>> --- /dev/null
>> +++ b/drivers/gpu/drm/sun4i/sun8i_layer.c
>> @@ -0,0 +1,142 @@
>> +/*
>> + * Copyright (C) Icenowy Zheng <icenowy@xxxxxxx>
>> + *
>> + * Based on sun4i_layer.h, which is:
>> + *   Copyright (C) 2015 Free Electrons
>> + *   Copyright (C) 2015 NextThing Co
>> + *
>> + *   Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
>> + *
>> + * 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_crtc.h>
>> +#include <drm/drm_plane_helper.h>
>> +#include <drm/drmP.h>
>> +
>> +#include "sun4i_crtc.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 int sun8i_mixer_layer_atomic_check(struct drm_plane *plane,
>> +					    struct drm_plane_state *state)
>> +{
>> +	return 0;
>> +}
>> +
>> +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_check	= sun8i_mixer_layer_atomic_check,
>> +	.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_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 sun4i_crtc *crtc)
>> +{
>> +	struct drm_plane **planes;
>> +	struct sun8i_mixer *mixer = crtc->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..fe7e8a069d71
>> --- /dev/null
>> +++ b/drivers/gpu/drm/sun4i/sun8i_layer.h
>> @@ -0,0 +1,36 @@
>> +/*
>> + * Copyright (C) Icenowy Zheng <icenowy@xxxxxxx>
>> + *
>> + * Based on sun4i_layer.h, which is:
>> + *   Copyright (C) 2015 Free Electrons
>> + *   Copyright (C) 2015 NextThing Co
>> + *
>> + *   Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
>> + *
>> + * 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 sun4i_crtc;
>> +
>> +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 sun4i_crtc *crtc);
>> +#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..5cff3f3833a7
>> --- /dev/null
>> +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
>> @@ -0,0 +1,381 @@
>> +/*
>> + * Copyright (C) 2017 Icenowy Zheng <icenowy@xxxxxxx>
>> + *
>> + * 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/reset.h>
>> +#include <linux/of_device.h>
>> +
>> +#include "sun4i_drv.h"
>> +#include "sun8i_mixer.h"
>> +#include "sun8i_layer.h"
>> +#include "sunxi_engine.h"
>> +
>> +void sun8i_mixer_commit(void *mixer)
>> +{
>> +	struct sun8i_mixer *sun8i_mixer = mixer;
>> +
>> +	DRM_DEBUG_DRIVER("Committing changes\n");
>> +
>> +	regmap_write(sun8i_mixer->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->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->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->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);
>> +}
>> +EXPORT_SYMBOL(sun8i_mixer_layer_enable);
>
>Why do you need to export it?

Oh... not needed. This export is dead code.

>
>> +
>> +static int sun8i_mixer_drm_format_to_layer(struct drm_plane *plane,
>> +					     u32 format, u32 *mode)
>> +{
>> +	switch (format) {
>> +	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->regs, SUN8I_MIXER_GLOBAL_SIZE,
>> +			     SUN8I_MIXER_SIZE(state->crtc_w,
>> +					      state->crtc_h));
>> +		DRM_DEBUG_DRIVER("Updating blender size\n");
>> +		regmap_write(mixer->regs,
>> +			     SUN8I_MIXER_BLEND_ATTR_INSIZE(0),
>> +			     SUN8I_MIXER_SIZE(state->crtc_w,
>> +					      state->crtc_h));
>> +		regmap_write(mixer->regs, SUN8I_MIXER_BLEND_OUTSIZE,
>> +			     SUN8I_MIXER_SIZE(state->crtc_w,
>> +					      state->crtc_h));
>> +		DRM_DEBUG_DRIVER("Updating channel size\n");
>> +		regmap_write(mixer->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->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->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->regs, SUN8I_MIXER_CHAN_UI_LAYER_COORD(chan,
>layer),
>> +		     SUN8I_MIXER_COORD(state->crtc_x, state->crtc_y));
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(sun8i_mixer_update_layer_coord);
>> +
>> +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->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");
>
>You're not using interlaced anywhere.

ok.

>
>> +
>> +	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->regs,
>> +			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(chan, layer),
>> +			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_FBFMT_MASK, val);
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(sun8i_mixer_update_layer_formats);
>> +
>> +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;
>> +	uint32_t paddr_u32;
>> +	/* 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];
>> +	paddr += (state->src_x >> 16) * bpp;
>> +	paddr += (state->src_y >> 16) * fb->pitches[0];
>> +
>> +	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
>> +
>> +	paddr_u32 = (uint32_t) paddr;
>
>How does that work on 64-bits systems ?

The hardware is not designed to work on 64-bit systems.

Even 64-bit A64/H5 has also 3GiB memory limit.

The address cell in mixer hardware is also only 32-bit.

So we should just keep the force conversion here. If we then really met 4GiB-capable AW SoC without changing DE2, I think we should have other way to limit CMA pool inside 4GiB.

>
>> +
>> +	regmap_write(mixer->regs,
>> +		     SUN8I_MIXER_CHAN_UI_LAYER_TOP_LADDR(chan, layer),
>> +		     paddr_u32);
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(sun8i_mixer_update_layer_buffer);
>> +
>> +static const struct sunxi_engine_ops sun8i_engine_ops = {
>> +	.commit = sun8i_mixer_commit,
>> +	.layers_init = sun8i_layers_init,
>
>Align with tabs.
>
>> +};
>> +
>> +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;
>> +
>> +	mixer = devm_kzalloc(dev, sizeof(*mixer), GFP_KERNEL);
>> +	if (!mixer)
>> +		return -ENOMEM;
>> +	dev_set_drvdata(dev, mixer);
>> +	drv->engine = mixer;
>> +	drv->engine_ops = &sun8i_engine_ops;
>> +
>> +	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->regs = devm_regmap_init_mmio(dev, regs,
>> +					      &sun8i_mixer_regmap_config);
>> +	if (IS_ERR(mixer->regs)) {
>> +		dev_err(dev, "Couldn't create the mixer regmap\n");
>> +		return PTR_ERR(mixer->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);
>> +
>> +	/* Reset the registers */
>> +	for (i = 0x0; i < 0x20000; i += 4)
>> +		regmap_write(mixer->regs, i, 0);
>> +
>> +	/* Enable the mixer */
>> +	regmap_write(mixer->regs, SUN8I_MIXER_GLOBAL_CTL,
>> +		     SUN8I_MIXER_GLOBAL_CTL_RT_EN);
>> +
>> +	/* Initialize blender */
>> +	regmap_write(mixer->regs, SUN8I_MIXER_BLEND_FCOLOR_CTL,
>> +		     SUN8I_MIXER_BLEND_FCOLOR_CTL_DEF);
>> +	regmap_write(mixer->regs, SUN8I_MIXER_BLEND_PREMULTIPLY,
>> +		     SUN8I_MIXER_BLEND_PREMULTIPLY_DEF);
>> +	regmap_write(mixer->regs, SUN8I_MIXER_BLEND_BKCOLOR,
>> +		     SUN8I_MIXER_BLEND_BKCOLOR_DEF);
>> +	regmap_write(mixer->regs, SUN8I_MIXER_BLEND_MODE(0),
>> +		     SUN8I_MIXER_BLEND_MODE_DEF);
>> +	regmap_write(mixer->regs, SUN8I_MIXER_BLEND_CK_CTL,
>> +		     SUN8I_MIXER_BLEND_CK_CTL_DEF);
>> +
>> +	regmap_write(mixer->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->regs, SUN8I_MIXER_BLEND_ROUTE,
>> +		     mixer->cfg->vi_num);
>> +
>> +	return 0;
>> +
>> +	clk_disable_unprepare(mixer->mod_clk);
>> +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);
>> +
>> +	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@xxxxxxx>");
>> +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..a4a365ae44c9
>> --- /dev/null
>> +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.h
>> @@ -0,0 +1,131 @@
>> +/*
>> + * Copyright (C) 2017 Icenowy Zheng <icenowy@xxxxxxx>
>> + *
>> + * 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 "sun4i_layer.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 regmap			*regs;
>> +
>> +	const struct sun8i_mixer_cfg	*cfg;
>> +
>> +	struct reset_control		*reset;
>> +
>> +	struct clk			*bus_clk;
>> +	struct clk			*mod_clk;
>> +};
>> +
>> +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_ */
>
>Thanks,
>Maxime