drm/tegra: Make legacy fbdev support optional

A lot of the modern userspace is capable of working without the legacy
fbdev support. kmscon can be used as a replacement for the framebuffer
console, and KMS X drivers create their own framebuffers.

Most people don't have a system where all of this works yet, though, so
leave support enabled by default.
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/Kconfig

@@ -3,13 +3,9 @@ config DRM_TEGRA
 	depends on ARCH_TEGRA || (ARM && COMPILE_TEST)
 	depends on DRM
 	depends on RESET_CONTROLLER
-	select DRM_KMS_FB_HELPER
 	select DRM_KMS_HELPER
 	select DRM_MIPI_DSI
 	select DRM_PANEL
-	select FB_SYS_FILLRECT
-	select FB_SYS_COPYAREA
-	select FB_SYS_IMAGEBLIT
 	select TEGRA_HOST1X
 	help
 	  Choose this option if you have an NVIDIA Tegra SoC.
@@ -19,6 +15,18 @@ config DRM_TEGRA
 
 if DRM_TEGRA
 
+config DRM_TEGRA_FBDEV
+	bool "Enable legacy fbdev support"
+	select DRM_KMS_FB_HELPER
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	default y
+	help
+	  Choose this option if you have a need for the legacy fbdev support.
+	  Note that this support also provides the Linux console on top of
+	  the Tegra modesetting driver.
+
 config DRM_TEGRA_DEBUG
 	bool "NVIDIA Tegra DRM debug support"
 	help

drivers/gpu/drm/tegra/drm.c

@@ -104,9 +104,11 @@ static void tegra_drm_context_free(struct tegra_drm_context *context)
 
 static void tegra_drm_lastclose(struct drm_device *drm)
 {
+#ifdef CONFIG_TEGRA_DRM_FBDEV
 	struct tegra_drm *tegra = drm->dev_private;
 
 	tegra_fbdev_restore_mode(tegra->fbdev);
+#endif
 }
 
 static struct host1x_bo *

drivers/gpu/drm/tegra/drm.h

@@ -27,10 +27,12 @@ struct tegra_fb {
 	unsigned int num_planes;
 };
 
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 struct tegra_fbdev {
 	struct drm_fb_helper base;
 	struct tegra_fb *fb;
 };
+#endif
 
 struct tegra_drm {
 	struct drm_device *drm;
@@ -38,7 +40,9 @@ struct tegra_drm {
 	struct mutex clients_lock;
 	struct list_head clients;
 
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 	struct tegra_fbdev *fbdev;
+#endif
 };
 
 struct tegra_drm_client;
@@ -265,7 +269,9 @@ bool tegra_fb_is_bottom_up(struct drm_framebuffer *framebuffer);
 bool tegra_fb_is_tiled(struct drm_framebuffer *framebuffer);
 extern int tegra_drm_fb_init(struct drm_device *drm);
 extern void tegra_drm_fb_exit(struct drm_device *drm);
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 extern void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev);
+#endif
 
 extern struct platform_driver tegra_dc_driver;
 extern struct platform_driver tegra_dsi_driver;

drivers/gpu/drm/tegra/fb.c

@@ -18,10 +18,12 @@ static inline struct tegra_fb *to_tegra_fb(struct drm_framebuffer *fb)
 	return container_of(fb, struct tegra_fb, base);
 }
 
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 static inline struct tegra_fbdev *to_tegra_fbdev(struct drm_fb_helper *helper)
 {
 	return container_of(helper, struct tegra_fbdev, base);
 }
+#endif
 
 struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,
 				    unsigned int index)
@@ -172,6 +174,7 @@ static struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 	return ERR_PTR(err);
 }
 
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 static struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_fillrect = sys_fillrect,
@@ -339,6 +342,15 @@ static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
 	kfree(fbdev);
 }
 
+void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev)
+{
+	if (fbdev) {
+		drm_modeset_lock_all(fbdev->base.dev);
+		drm_fb_helper_restore_fbdev_mode(&fbdev->base);
+		drm_modeset_unlock_all(fbdev->base.dev);
+	}
+}
+
 static void tegra_fb_output_poll_changed(struct drm_device *drm)
 {
 	struct tegra_drm *tegra = drm->dev_private;
@@ -346,16 +358,20 @@ static void tegra_fb_output_poll_changed(struct drm_device *drm)
 	if (tegra->fbdev)
 		drm_fb_helper_hotplug_event(&tegra->fbdev->base);
 }
+#endif
 
 static const struct drm_mode_config_funcs tegra_drm_mode_funcs = {
 	.fb_create = tegra_fb_create,
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 	.output_poll_changed = tegra_fb_output_poll_changed,
+#endif
 };
 
 int tegra_drm_fb_init(struct drm_device *drm)
 {
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 	struct tegra_drm *tegra = drm->dev_private;
-	struct tegra_fbdev *fbdev;
+#endif
 
 	drm->mode_config.min_width = 0;
 	drm->mode_config.min_height = 0;
@@ -365,28 +381,21 @@ int tegra_drm_fb_init(struct drm_device *drm)
 
 	drm->mode_config.funcs = &tegra_drm_mode_funcs;
 
-	fbdev = tegra_fbdev_create(drm, 32, drm->mode_config.num_crtc,
-				   drm->mode_config.num_connector);
-	if (IS_ERR(fbdev))
-		return PTR_ERR(fbdev);
-
-	tegra->fbdev = fbdev;
+#ifdef CONFIG_DRM_TEGRA_FBDEV
+	tegra->fbdev = tegra_fbdev_create(drm, 32, drm->mode_config.num_crtc,
+					  drm->mode_config.num_connector);
+	if (IS_ERR(tegra->fbdev))
+		return PTR_ERR(tegra->fbdev);
+#endif
 
 	return 0;
 }
 
 void tegra_drm_fb_exit(struct drm_device *drm)
 {
+#ifdef CONFIG_DRM_TEGRA_FBDEV
 	struct tegra_drm *tegra = drm->dev_private;
 
 	tegra_fbdev_free(tegra->fbdev);
-}
-
-void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev)
-{
-	if (fbdev) {
-		drm_modeset_lock_all(fbdev->base.dev);
-		drm_fb_helper_restore_fbdev_mode(&fbdev->base);
-		drm_modeset_unlock_all(fbdev->base.dev);
-	}
+#endif
 }