Re: [PATCH v6 08/13] drm/sun4i: add support for Allwinner DE2 mixers

From: icenowy
Date: Thu May 04 2017 - 13:14:57 EST


å 2017-05-05 00:57ïicenowy@xxxxxxx åéï
å 2017-05-05 00:50ïicenowy@xxxxxxx åéï
å 2017-05-04 21:05ïMaxime Ripard åéï
On Thu, May 04, 2017 at 07:48:53PM +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 v6:
- Rebased on wens's multi-pipeline patchset.
Changes in v5:
- Changed some code alignment.
- Request real 32-bit DMA (prepare for 64-bit SoCs).
Changes in v4:
- Killed some dead code according to Jernej.

drivers/gpu/drm/sun4i/Kconfig | 10 +
drivers/gpu/drm/sun4i/Makefile | 3 +
drivers/gpu/drm/sun4i/sun8i_layer.c | 140 +++++++++++++
drivers/gpu/drm/sun4i/sun8i_layer.h | 36 ++++
drivers/gpu/drm/sun4i/sun8i_mixer.c | 394 ++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/sun4i/sun8i_mixer.h | 137 +++++++++++++
6 files changed, 720 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

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 a08df56759e3..a876c6b3027c 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -8,7 +8,10 @@ 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_BACKEND) += sun4i-backend.o
+obj-$(CONFIG_DRM_SUN4I_SUN8I_MIXER) += sun8i-mixer.o
obj-$(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..48f33d8e013b
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_layer.c
@@ -0,0 +1,140 @@
+/*
+ * 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_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 int sun8i_mixer_layer_atomic_check(struct drm_plane *plane,
+ struct drm_plane_state *state)
+{
+ return 0;
+}

This isn't needed.

+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 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@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 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..e216b84d5bb2
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
@@ -0,0 +1,394 @@
+/*
+ * 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/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"
+
+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);
+}

This function can be static

+
+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);
+}

This one too.

It's called from sun8i_layer.c, so it cannot be static.


+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->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));

X and Y are fixed point numbers. You want to keep only the higher 16
bits there.

Do you mean "lower 16 bits"? Thus should I (x & 0xffff) or ((u16)x) ?

Oh sorry, it's 16.16 ...

Went wrong again... it's surely not 16.16 .
crtc_* is integer, and src_* is 16.16 .


I'm misled by the sun4i_backend driver.

May I soon send out a patch to fix the sun4i_backend?


P.S. The negative coordinates are broken, how should I deal with it? or
is the coordinates promised to be not negative?

But surely we should deal with the failure of negative values.

I think I should hack the update_layer_buffer function to deal with the
failure of negative coordinates. -- The status of negative coordinate is
that the display size is croped, but at (0,0) the pixel displayed is still
the original (0,0), not the (-crtc_x, -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];
+ paddr += (state->src_x >> 16) * bpp;
+ paddr += (state->src_y >> 16) * 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;
+
+ 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);

You didn't call INIT_LIST_HEAD on that 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;
+
+ clk_disable_unprepare(mixer->mod_clk);

This line cannot be reached.

Maxime