drm/sti: Use drm_fb_cma_fbdev_init/fini()

Use drm_fb_cma_fbdev_init() and drm_fb_cma_fbdev_fini() which relies on
the fact that drm_device holds a pointer to the drm_fb_helper structure.
This means that the driver doesn't have to keep track of that.
Also use the drm_fb_helper functions directly.

Cc: Benjamin Gaignard <[e-mail]>
Cc: Vincent Abriou <[e-mail]>
Signed-off-by: Noralf Trønnes <[e-mail]>
Acked-by: Benjamin Gaignard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/sti/sti_drv.c

···
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_of.h>
 
···
 	return ret;
 }
 
-static void sti_output_poll_changed(struct drm_device *ddev)
-{
-	struct sti_private *private = ddev->dev_private;
-
-	drm_fbdev_cma_hotplug_event(private->fbdev);
-}
-
 static const struct drm_mode_config_funcs sti_mode_config_funcs = {
 	.fb_create = drm_gem_fb_create,
-	.output_poll_changed = sti_output_poll_changed,
+	.output_poll_changed = drm_fb_helper_output_poll_changed,
 	.atomic_check = sti_atomic_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };
···
 {
 	struct sti_private *private = ddev->dev_private;
 
-	if (private->fbdev) {
-		drm_fbdev_cma_fini(private->fbdev);
-		private->fbdev = NULL;
-	}
-
+	drm_fb_cma_fbdev_fini(ddev);
 	drm_kms_helper_poll_fini(ddev);
 	component_unbind_all(ddev->dev, ddev);
 	kfree(private);
···
 static int sti_bind(struct device *dev)
 {
 	struct drm_device *ddev;
-	struct sti_private *private;
-	struct drm_fbdev_cma *fbdev;
 	int ret;
 
 	ddev = drm_dev_alloc(&sti_driver, dev);
···
 
 	drm_mode_config_reset(ddev);
 
-	private = ddev->dev_private;
 	if (ddev->mode_config.num_connector) {
-		fbdev = drm_fbdev_cma_init(ddev, 32,
-					   ddev->mode_config.num_connector);
-		if (IS_ERR(fbdev)) {
+		ret = drm_fb_cma_fbdev_init(ddev, 32, 0);
+		if (ret)
 			DRM_DEBUG_DRIVER("Warning: fails to create fbdev\n");
-			fbdev = NULL;
-		}
-		private->fbdev = fbdev;
 	}
 
 	return 0;

drivers/gpu/drm/sti/sti_drv.h

···
 	struct sti_compositor *compo;
 	struct drm_property *plane_zorder_property;
 	struct drm_device *drm_dev;
-	struct drm_fbdev_cma *fbdev;
 };
 
 extern struct platform_driver sti_tvout_driver;