drm/sun4i: 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: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025201340.34227-8-noralf@tronnes.org

drivers/gpu/drm/sun4i/sun4i_drv.c

@@ -34,7 +34,6 @@ static struct drm_driver sun4i_drv_driver = {
 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_ATOMIC,
 
 	/* Generic Operations */
-	.lastclose		= drm_fb_helper_lastclose,
 	.fops			= &sun4i_drv_fops,
 	.name			= "sun4i-drm",
 	.desc			= "Allwinner sun4i Display Engine",
@@ -105,12 +104,7 @@ static int sun4i_drv_bind(struct device *dev)
 	/* Remove early framebuffers (ie. simplefb) */
 	drm_fb_helper_remove_conflicting_framebuffers(NULL, "sun4i-drm-fb", false);
 
-	/* Create our framebuffer */
-	ret = sun4i_framebuffer_init(drm);
-	if (ret) {
-		dev_err(drm->dev, "Couldn't create our framebuffer\n");
-		goto cleanup_mode_config;
-	}
+	sun4i_framebuffer_init(drm);
 
 	/* Enable connectors polling */
 	drm_kms_helper_poll_init(drm);
@@ -119,11 +113,12 @@ static int sun4i_drv_bind(struct device *dev)
 	if (ret)
 		goto finish_poll;
 
+	drm_fbdev_generic_setup(drm, 32);
+
 	return 0;
 
 finish_poll:
 	drm_kms_helper_poll_fini(drm);
-	sun4i_framebuffer_free(drm);
 cleanup_mode_config:
 	drm_mode_config_cleanup(drm);
 	of_reserved_mem_device_release(dev);
@@ -138,7 +133,6 @@ static void sun4i_drv_unbind(struct device *dev)
 
 	drm_dev_unregister(drm);
 	drm_kms_helper_poll_fini(drm);
-	sun4i_framebuffer_free(drm);
 	drm_mode_config_cleanup(drm);
 	of_reserved_mem_device_release(dev);
 	drm_dev_put(drm);

drivers/gpu/drm/sun4i/sun4i_framebuffer.c

@@ -12,8 +12,6 @@
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_fb_helper.h>
-#include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drmP.h>
 
@@ -37,7 +35,6 @@ static int sun4i_de_atomic_check(struct drm_device *dev,
 }
 
 static const struct drm_mode_config_funcs sun4i_de_mode_config_funcs = {
-	.output_poll_changed	= drm_fb_helper_output_poll_changed,
 	.atomic_check		= sun4i_de_atomic_check,
 	.atomic_commit		= drm_atomic_helper_commit,
 	.fb_create		= drm_gem_fb_create,
@@ -47,7 +44,7 @@ static struct drm_mode_config_helper_funcs sun4i_de_mode_config_helpers = {
 	.atomic_commit_tail	= drm_atomic_helper_commit_tail_rpm,
 };
 
-int sun4i_framebuffer_init(struct drm_device *drm)
+void sun4i_framebuffer_init(struct drm_device *drm)
 {
 	drm_mode_config_reset(drm);
 
@@ -56,11 +53,4 @@ int sun4i_framebuffer_init(struct drm_device *drm)
 
 	drm->mode_config.funcs = &sun4i_de_mode_config_funcs;
 	drm->mode_config.helper_private = &sun4i_de_mode_config_helpers;
-
-	return drm_fb_cma_fbdev_init(drm, 32, 0);
-}
-
-void sun4i_framebuffer_free(struct drm_device *drm)
-{
-	drm_fb_cma_fbdev_fini(drm);
 }

drivers/gpu/drm/sun4i/sun4i_framebuffer.h

@@ -13,7 +13,6 @@
 #ifndef _SUN4I_FRAMEBUFFER_H_
 #define _SUN4I_FRAMEBUFFER_H_
 
-int sun4i_framebuffer_init(struct drm_device *drm);
-void sun4i_framebuffer_free(struct drm_device *drm);
+void sun4i_framebuffer_init(struct drm_device *drm);
 
 #endif /* _SUN4I_FRAMEBUFFER_H_ */