drm/meson: Use drm_fbdev_generic_setup()

The CMA helper is already using the drm_fb_helper_generic_probe part of
the generic fbdev emulation. This patch makes full use of the generic
fbdev emulation by using its drm_client callbacks. This means that
drm_mode_config_funcs->output_poll_changed and drm_driver->lastclose are
now handled by the emulation code. Additionally fbdev unregister happens
automatically on drm_dev_unregister().

The drm_fbdev_generic_setup() call is put after drm_dev_register() in the
driver. This is done to highlight the fact that fbdev emulation is an
internal client that makes use of the driver, it is not part of the
driver as such. If fbdev setup fails, an error is printed, but the driver
succeeds probing.

Cc: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180908134648.2582-6-noralf@tronnes.org

drivers/gpu/drm/meson/meson_drv.c

@@ -68,15 +68,7 @@
  * - Powering Up HDMI controller and PHY
  */
 
-static void meson_fb_output_poll_changed(struct drm_device *dev)
-{
-	struct meson_drm *priv = dev->dev_private;
-
-	drm_fbdev_cma_hotplug_event(priv->fbdev);
-}
-
 static const struct drm_mode_config_funcs meson_mode_config_funcs = {
-	.output_poll_changed = meson_fb_output_poll_changed,
 	.atomic_check        = drm_atomic_helper_check,
 	.atomic_commit       = drm_atomic_helper_commit,
 	.fb_create           = drm_gem_fb_create,
@@ -282,13 +274,6 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 
 	drm_mode_config_reset(drm);
 
-	priv->fbdev = drm_fbdev_cma_init(drm, 32,
-					 drm->mode_config.num_connector);
-	if (IS_ERR(priv->fbdev)) {
-		ret = PTR_ERR(priv->fbdev);
-		goto free_drm;
-	}
-
 	drm_kms_helper_poll_init(drm);
 
 	platform_set_drvdata(pdev, priv);
@@ -297,6 +282,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	if (ret)
 		goto free_drm;
 
+	drm_fbdev_generic_setup(drm, 32);
+
 	return 0;
 
 free_drm:
@@ -313,11 +300,9 @@ static int meson_drv_bind(struct device *dev)
 static void meson_drv_unbind(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);
-	struct meson_drm *priv = drm->dev_private;
 
 	drm_dev_unregister(drm);
 	drm_kms_helper_poll_fini(drm);
-	drm_fbdev_cma_fini(priv->fbdev);
 	drm_mode_config_cleanup(drm);
 	drm_dev_put(drm);
 

drivers/gpu/drm/meson/meson_drv.h

@@ -33,7 +33,6 @@ struct meson_drm {
 
 	struct drm_device *drm;
 	struct drm_crtc *crtc;
-	struct drm_fbdev_cma *fbdev;
 	struct drm_plane *primary_plane;
 
 	/* Components Data */