drm/amdgpu: Use new drm_fb_helper functions

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- Fixed PTR_ERR issue mentioned by kbuild bot

Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c

@@ -53,9 +53,9 @@ static struct fb_ops amdgpufb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = drm_fb_helper_check_var,
 	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = cfb_fillrect,
-	.fb_copyarea = cfb_copyarea,
-	.fb_imageblit = cfb_imageblit,
+	.fb_fillrect = drm_fb_helper_cfb_fillrect,
+	.fb_copyarea = drm_fb_helper_cfb_copyarea,
+	.fb_imageblit = drm_fb_helper_cfb_imageblit,
 	.fb_pan_display = drm_fb_helper_pan_display,
 	.fb_blank = drm_fb_helper_blank,
 	.fb_setcmap = drm_fb_helper_setcmap,
@@ -179,7 +179,6 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 	struct drm_mode_fb_cmd2 mode_cmd;
 	struct drm_gem_object *gobj = NULL;
 	struct amdgpu_bo *rbo = NULL;
-	struct device *device = &adev->pdev->dev;
 	int ret;
 	unsigned long tmp;
 
@@ -201,9 +200,9 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 	rbo = gem_to_amdgpu_bo(gobj);
 
 	/* okay we have an object now allocate the framebuffer */
-	info = framebuffer_alloc(0, device);
-	if (info == NULL) {
-		ret = -ENOMEM;
+	info = drm_fb_helper_alloc_fbi(helper);
+	if (IS_ERR(info)) {
+		ret = PTR_ERR(info);
 		goto out_unref;
 	}
 
@@ -212,14 +211,13 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 	ret = amdgpu_framebuffer_init(adev->ddev, &rfbdev->rfb, &mode_cmd, gobj);
 	if (ret) {
 		DRM_ERROR("failed to initialize framebuffer %d\n", ret);
-		goto out_unref;
+		goto out_destroy_fbi;
 	}
 
 	fb = &rfbdev->rfb.base;
 
 	/* setup helper */
 	rfbdev->helper.fb = fb;
-	rfbdev->helper.fbdev = info;
 
 	memset_io(rbo->kptr, 0x0, amdgpu_bo_size(rbo));
 
@@ -239,11 +237,6 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 	drm_fb_helper_fill_var(info, &rfbdev->helper, sizes->fb_width, sizes->fb_height);
 
 	/* setup aperture base/size for vesafb takeover */
-	info->apertures = alloc_apertures(1);
-	if (!info->apertures) {
-		ret = -ENOMEM;
-		goto out_unref;
-	}
 	info->apertures->ranges[0].base = adev->ddev->mode_config.fb_base;
 	info->apertures->ranges[0].size = adev->mc.aper_size;
 
@@ -251,13 +244,7 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 
 	if (info->screen_base == NULL) {
 		ret = -ENOSPC;
-		goto out_unref;
-	}
-
-	ret = fb_alloc_cmap(&info->cmap, 256, 0);
-	if (ret) {
-		ret = -ENOMEM;
-		goto out_unref;
+		goto out_destroy_fbi;
 	}
 
 	DRM_INFO("fb mappable at 0x%lX\n",  info->fix.smem_start);
@@ -269,6 +256,8 @@ static int amdgpufb_create(struct drm_fb_helper *helper,
 	vga_switcheroo_client_fb_set(adev->ddev->pdev, info);
 	return 0;
 
+out_destroy_fbi:
+	drm_fb_helper_release_fbi(helper);
 out_unref:
 	if (rbo) {
 
@@ -290,17 +279,10 @@ void amdgpu_fb_output_poll_changed(struct amdgpu_device *adev)
 
 static int amdgpu_fbdev_destroy(struct drm_device *dev, struct amdgpu_fbdev *rfbdev)
 {
-	struct fb_info *info;
 	struct amdgpu_framebuffer *rfb = &rfbdev->rfb;
 
-	if (rfbdev->helper.fbdev) {
-		info = rfbdev->helper.fbdev;
-
-		unregister_framebuffer(info);
-		if (info->cmap.len)
-			fb_dealloc_cmap(&info->cmap);
-		framebuffer_release(info);
-	}
+	drm_fb_helper_unregister_fbi(&rfbdev->helper);
+	drm_fb_helper_release_fbi(&rfbdev->helper);
 
 	if (rfb->obj) {
 		amdgpufb_destroy_pinned_object(rfb->obj);
@@ -395,7 +377,8 @@ void amdgpu_fbdev_fini(struct amdgpu_device *adev)
 void amdgpu_fbdev_set_suspend(struct amdgpu_device *adev, int state)
 {
 	if (adev->mode_info.rfbdev)
-		fb_set_suspend(adev->mode_info.rfbdev->helper.fbdev, state);
+		drm_fb_helper_set_suspend(&adev->mode_info.rfbdev->helper,
+			state);
 }
 
 int amdgpu_fbdev_total_size(struct amdgpu_device *adev)