drm/rockchip: fbdev: reintroduction rockchip drm fbdev

drm_fbdev_generic_setup(drm_dev, 0) register fbdev will register drm
client and lead to display black screen after kernel logo, so we
reintroduction rockchip drm fbdev.

fbdev register drm client will show black screen:

drm_kms_helper_hotplug_event
  ->drm_client_dev_hotplug
    ->client->funcs->hotplug
      ->drm_fbdev_client_hotplug
        ->drm_fb_helper_hotplug_event
          ->drm_fb_helper_set_par
            ...
              -> drm_atomic_commit

Signed-off-by: Sandy Huang <hjc@rock-chips.com>
Change-Id: Id2725e26c633c9ef5f4bd01f9f4fa45c072e8ef9

drivers/gpu/drm/rockchip/Makefile

@@ -6,6 +6,7 @@
 rockchipdrm-y := rockchip_drm_drv.o rockchip_drm_fb.o \
 		 rockchip_drm_gem.o rockchip_drm_logo.o rockchip_drm_clk.o\
 
+rockchipdrm-$(CONFIG_DRM_FBDEV_EMULATION) += rockchip_drm_fbdev.o
 rockchipdrm-$(CONFIG_ROCKCHIP_DRM_DEBUG) += rockchip_drm_debugfs.o
 rockchipdrm-$(CONFIG_ROCKCHIP_DRM_DIRECT_SHOW) += rockchip_drm_direct_show.o
 rockchipdrm-$(CONFIG_ROCKCHIP_DRM_SELF_TEST) += rockchip_drm_display_pattern.o	\

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -41,6 +41,7 @@
 
 #include "rockchip_drm_drv.h"
 #include "rockchip_drm_fb.h"
+#include "rockchip_drm_fbdev.h"
 #include "rockchip_drm_gem.h"
 #include "rockchip_drm_logo.h"
 
@@ -1722,11 +1723,19 @@ static int rockchip_drm_bind(struct device *dev)
 	if (ret)
 		goto err_kms_helper_poll_fini;
 
-	drm_fbdev_generic_setup(drm_dev, 0);
+	ret = rockchip_drm_fbdev_init(drm_dev);
+	if (ret)
+		goto err_drm_dev_unregister;
 
-	rockchip_drm_sysfs_init(drm_dev);
+	ret = rockchip_drm_sysfs_init(drm_dev);
+	if (ret)
+		goto err_drm_fbdev_fini;
 
 	return 0;
+err_drm_fbdev_fini:
+	rockchip_drm_fbdev_fini(drm_dev);
+err_drm_dev_unregister:
+	drm_dev_unregister(drm_dev);
 err_kms_helper_poll_fini:
 	rockchip_gem_pool_destroy(drm_dev);
 	drm_kms_helper_poll_fini(drm_dev);
@@ -1747,6 +1756,7 @@ static void rockchip_drm_unbind(struct device *dev)
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
 
 	rockchip_drm_sysfs_fini(drm_dev);
+	rockchip_drm_fbdev_fini(drm_dev);
 	drm_dev_unregister(drm_dev);
 
 	rockchip_gem_pool_destroy(drm_dev);

drivers/gpu/drm/rockchip/rockchip_drm_fb.c

@@ -389,6 +389,20 @@ static const struct drm_mode_config_funcs rockchip_drm_mode_config_funcs = {
 	.atomic_commit = drm_atomic_helper_commit,
 };
 
+struct drm_framebuffer *
+rockchip_drm_framebuffer_init(struct drm_device *dev,
+			      const struct drm_mode_fb_cmd2 *mode_cmd,
+			      struct drm_gem_object *obj)
+{
+	struct drm_framebuffer *fb;
+
+	fb = rockchip_fb_alloc(dev, mode_cmd, &obj, 1);
+	if (IS_ERR(fb))
+		return ERR_CAST(fb);
+
+	return fb;
+}
+
 void rockchip_drm_mode_config_init(struct drm_device *dev)
 {
 	dev->mode_config.min_width = 0;

drivers/gpu/drm/rockchip/rockchip_drm_fb.h

@@ -11,6 +11,10 @@
 #include "rockchip_drm_gem.h"
 
 #define ROCKCHIP_DRM_MODE_LOGO_FB	(1<<31) /* used for kernel logo, follow the define: DRM_MODE_FB_MODIFIERS at drm_mode.h */
+struct drm_framebuffer *
+rockchip_drm_framebuffer_init(struct drm_device *dev,
+			      const struct drm_mode_fb_cmd2 *mode_cmd,
+			      struct drm_gem_object *obj);
 
 void rockchip_drm_mode_config_init(struct drm_device *dev);
 struct drm_framebuffer *

drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c

@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author:Mark Yao <mark.yao@rock-chips.com>
+ */
+
+#include <drm/drm.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_probe_helper.h>
+
+#include "rockchip_drm_drv.h"
+#include "rockchip_drm_gem.h"
+#include "rockchip_drm_fb.h"
+#include "rockchip_drm_fbdev.h"
+
+#define PREFERRED_BPP		32
+
+static int rockchip_fbdev_mmap(struct fb_info *info,
+			       struct vm_area_struct *vma)
+{
+	struct drm_fb_helper *helper = info->par;
+	struct rockchip_drm_private *private = helper->dev->dev_private;
+
+	return rockchip_gem_mmap_buf(private->fbdev_bo, vma);
+}
+
+static const struct fb_ops rockchip_drm_fbdev_ops = {
+	.owner		= THIS_MODULE,
+	DRM_FB_HELPER_DEFAULT_OPS,
+	.fb_mmap	= rockchip_fbdev_mmap,
+	.fb_fillrect	= drm_fb_helper_cfb_fillrect,
+	.fb_copyarea	= drm_fb_helper_cfb_copyarea,
+	.fb_imageblit	= drm_fb_helper_cfb_imageblit,
+};
+
+static int rockchip_drm_fbdev_create(struct drm_fb_helper *helper,
+				     struct drm_fb_helper_surface_size *sizes)
+{
+	struct rockchip_drm_private *private = helper->dev->dev_private;
+	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
+	struct drm_device *dev = helper->dev;
+	struct rockchip_gem_object *rk_obj;
+	struct drm_framebuffer *fb;
+	unsigned int bytes_per_pixel;
+	unsigned long offset;
+	struct fb_info *fbi;
+	size_t size;
+	int ret;
+
+	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
+
+	mode_cmd.width = sizes->surface_width;
+	mode_cmd.height = sizes->surface_height;
+	mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
+	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+		sizes->surface_depth);
+
+	size = mode_cmd.pitches[0] * mode_cmd.height;
+
+	rk_obj = rockchip_gem_create_object(dev, size, true, 0);
+	if (IS_ERR(rk_obj))
+		return -ENOMEM;
+
+	private->fbdev_bo = &rk_obj->base;
+
+	fbi = drm_fb_helper_alloc_fbi(helper);
+	if (IS_ERR(fbi)) {
+		DRM_DEV_ERROR(dev->dev, "Failed to create framebuffer info.\n");
+		ret = PTR_ERR(fbi);
+		goto out;
+	}
+
+	helper->fb = rockchip_drm_framebuffer_init(dev, &mode_cmd,
+						   private->fbdev_bo);
+	if (IS_ERR(helper->fb)) {
+		DRM_DEV_ERROR(dev->dev,
+			      "Failed to allocate DRM framebuffer.\n");
+		ret = PTR_ERR(helper->fb);
+		goto out;
+	}
+
+	fbi->fbops = &rockchip_drm_fbdev_ops;
+
+	fb = helper->fb;
+	drm_fb_helper_fill_info(fbi, helper, sizes);
+
+	offset = fbi->var.xoffset * bytes_per_pixel;
+	offset += fbi->var.yoffset * fb->pitches[0];
+
+	dev->mode_config.fb_base = 0;
+	fbi->screen_base = rk_obj->kvaddr + offset;
+	fbi->screen_size = rk_obj->base.size;
+	fbi->fix.smem_len = rk_obj->base.size;
+
+	DRM_DEBUG_KMS("FB [%dx%d]-%d kvaddr=%p offset=%ld size=%zu\n",
+		      fb->width, fb->height, fb->format->depth,
+		      rk_obj->kvaddr,
+		      offset, size);
+
+	return 0;
+
+out:
+	drm_gem_object_put(&rk_obj->base);
+	return ret;
+}
+
+static const struct drm_fb_helper_funcs rockchip_drm_fb_helper_funcs = {
+	.fb_probe = rockchip_drm_fbdev_create,
+};
+
+int rockchip_drm_fbdev_init(struct drm_device *dev)
+{
+	struct rockchip_drm_private *private = dev->dev_private;
+	struct drm_fb_helper *helper;
+	int ret;
+
+	if (!dev->mode_config.num_crtc || !dev->mode_config.num_connector)
+		return -EINVAL;
+
+	helper = devm_kzalloc(dev->dev, sizeof(*helper), GFP_KERNEL);
+	if (!helper)
+		return -ENOMEM;
+	private->fbdev_helper = helper;
+
+	drm_fb_helper_prepare(dev, helper, &rockchip_drm_fb_helper_funcs);
+
+	ret = drm_fb_helper_init(dev, helper);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev->dev,
+			      "Failed to initialize drm fb helper - %d.\n",
+			      ret);
+		return ret;
+	}
+
+	ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev->dev,
+			      "Failed to set initial hw config - %d.\n",
+			      ret);
+		goto err_drm_fb_helper_fini;
+	}
+
+	return 0;
+
+err_drm_fb_helper_fini:
+	drm_fb_helper_fini(helper);
+	return ret;
+}
+
+void rockchip_drm_fbdev_fini(struct drm_device *dev)
+{
+	struct rockchip_drm_private *private = dev->dev_private;
+	struct drm_fb_helper *helper = private->fbdev_helper;
+
+	if (!helper)
+		return;
+
+	drm_fb_helper_unregister_fbi(helper);
+
+	if (helper->fb)
+		drm_framebuffer_put(helper->fb);
+
+	drm_fb_helper_fini(helper);
+}

drivers/gpu/drm/rockchip/rockchip_drm_fbdev.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author:Mark Yao <mark.yao@rock-chips.com>
+ */
+
+#ifndef _ROCKCHIP_DRM_FBDEV_H
+#define _ROCKCHIP_DRM_FBDEV_H
+
+#if defined(CONFIG_DRM_FBDEV_EMULATION)
+int rockchip_drm_fbdev_init(struct drm_device *dev);
+void rockchip_drm_fbdev_fini(struct drm_device *dev);
+#else
+static inline int rockchip_drm_fbdev_init(struct drm_device *dev)
+{
+	return 0;
+}
+
+static inline void rockchip_drm_fbdev_fini(struct drm_device *dev)
+{
+}
+#endif
+
+#endif /* _ROCKCHIP_DRM_FBDEV_H */

drivers/gpu/drm/rockchip/rockchip_drm_gem.c

@@ -594,6 +594,18 @@ const struct drm_gem_object_funcs rockchip_gem_object_funcs = {
 	.vm_ops = &drm_gem_dma_vm_ops,
 };
 
+int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
+			  struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = drm_gem_mmap_obj(obj, obj->size, vma);
+	if (ret)
+		return ret;
+
+	return rockchip_drm_gem_object_mmap(obj, vma);
+}
+
 static struct rockchip_gem_object *
 rockchip_gem_alloc_object(struct drm_device *drm, unsigned int size,
 			  unsigned int flags)

drivers/gpu/drm/rockchip/rockchip_drm_gem.h

@@ -54,6 +54,10 @@ void rockchip_gem_free_object(struct drm_gem_object *obj);
 int rockchip_gem_dumb_create(struct drm_file *file_priv,
 			     struct drm_device *dev,
 			     struct drm_mode_create_dumb *args);
+/* mmap a gem object to userspace. */
+int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
+			  struct vm_area_struct *vma);
+
 /*
  * request gem object creation and buffer allocation as the size
  * that it is calculated with framebuffer information such as width,