drm/tinydrm: Use drm_fb_cma_fbdev_init_with_funcs/fini()

Use drm_fb_cma_fbdev_init_with_funcs() 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.
Remove todo entry.

Cc: David Lechner <david@lechnology.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: David Lechner <david@lechnology.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: David Lechner <david@lechnolgy.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171208193743.34450-11-noralf@tronnes.org

Documentation/gpu/todo.rst

@@ -395,11 +395,6 @@ those drivers as simple as possible, so lots of room for refactoring:
   one of the ideas for having a shared dsi/dbi helper, abstracting away the
   transport details more.
 
-- tinydrm_lastclose could be drm_fb_helper_lastclose. Only thing we need
-  for that is to store the drm_fb_helper pointer somewhere in
-  drm_device->mode_config. And then we could roll that out to all the
-  drivers.
-
 - tinydrm_gem_cma_prime_import_sg_table should probably go into the cma
   helpers, as a _vmapped variant (since not every driver needs the vmap).
   And tinydrm_gem_cma_free_object could the be merged into

drivers/gpu/drm/tinydrm/core/tinydrm-core.c

@@ -10,6 +10,7 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/tinydrm/tinydrm.h>
 #include <linux/device.h>
@@ -35,23 +36,6 @@
  * and registers the DRM device using devm_tinydrm_register().
  */
 
-/**
- * tinydrm_lastclose - DRM lastclose helper
- * @drm: DRM device
- *
- * This function ensures that fbdev is restored when drm_lastclose() is called
- * on the last drm_release(). Drivers can use this as their
- * &drm_driver->lastclose callback.
- */
-void tinydrm_lastclose(struct drm_device *drm)
-{
-	struct tinydrm_device *tdev = drm->dev_private;
-
-	DRM_DEBUG_KMS("\n");
-	drm_fbdev_cma_restore_mode(tdev->fbdev_cma);
-}
-EXPORT_SYMBOL(tinydrm_lastclose);
-
 /**
  * tinydrm_gem_cma_prime_import_sg_table - Produce a CMA GEM object from
  *     another driver's scatter/gather table of pinned pages
@@ -214,35 +198,24 @@ EXPORT_SYMBOL(devm_tinydrm_init);
 static int tinydrm_register(struct tinydrm_device *tdev)
 {
 	struct drm_device *drm = tdev->drm;
-	int bpp = drm->mode_config.preferred_depth;
-	struct drm_fbdev_cma *fbdev;
 	int ret;
 
 	ret = drm_dev_register(tdev->drm, 0);
 	if (ret)
 		return ret;
 
-	fbdev = drm_fbdev_cma_init_with_funcs(drm, bpp ? bpp : 32,
-					      drm->mode_config.num_connector,
-					      tdev->fb_funcs);
-	if (IS_ERR(fbdev))
-		DRM_ERROR("Failed to initialize fbdev: %ld\n", PTR_ERR(fbdev));
-	else
-		tdev->fbdev_cma = fbdev;
+	ret = drm_fb_cma_fbdev_init_with_funcs(drm, 0, 0, tdev->fb_funcs);
+	if (ret)
+		DRM_ERROR("Failed to initialize fbdev: %d\n", ret);
 
 	return 0;
 }
 
 static void tinydrm_unregister(struct tinydrm_device *tdev)
 {
-	struct drm_fbdev_cma *fbdev_cma = tdev->fbdev_cma;
-
 	drm_atomic_helper_shutdown(tdev->drm);
-	/* don't restore fbdev in lastclose, keep pipeline disabled */
-	tdev->fbdev_cma = NULL;
+	drm_fb_cma_fbdev_fini(tdev->drm);
 	drm_dev_unregister(tdev->drm);
-	if (fbdev_cma)
-		drm_fbdev_cma_fini(fbdev_cma);
 }
 
 static void devm_tinydrm_register_release(void *data)

drivers/gpu/drm/tinydrm/ili9225.c

@@ -20,6 +20,7 @@
 #include <linux/spi/spi.h>
 #include <video/mipi_display.h>
 
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/tinydrm/mipi-dbi.h>
 #include <drm/tinydrm/tinydrm-helpers.h>
@@ -381,7 +382,7 @@ static struct drm_driver ili9225_driver = {
 				  DRIVER_ATOMIC,
 	.fops			= &ili9225_fops,
 	TINYDRM_GEM_DRIVER_OPS,
-	.lastclose		= tinydrm_lastclose,
+	.lastclose		= drm_fb_helper_lastclose,
 	.name			= "ili9225",
 	.desc			= "Ilitek ILI9225",
 	.date			= "20171106",

drivers/gpu/drm/tinydrm/mi0283qt.c

@@ -9,6 +9,7 @@
  * (at your option) any later version.
  */
 
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/tinydrm/ili9341.h>
 #include <drm/tinydrm/mipi-dbi.h>
@@ -140,7 +141,7 @@ static struct drm_driver mi0283qt_driver = {
 				  DRIVER_ATOMIC,
 	.fops			= &mi0283qt_fops,
 	TINYDRM_GEM_DRIVER_OPS,
-	.lastclose		= tinydrm_lastclose,
+	.lastclose		= drm_fb_helper_lastclose,
 	.debugfs_init		= mipi_dbi_debugfs_init,
 	.name			= "mi0283qt",
 	.desc			= "Multi-Inno MI0283QT",

drivers/gpu/drm/tinydrm/st7586.c

@@ -17,6 +17,7 @@
 #include <linux/spi/spi.h>
 #include <video/mipi_display.h>
 
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/tinydrm/mipi-dbi.h>
 #include <drm/tinydrm/tinydrm-helpers.h>
@@ -320,7 +321,7 @@ static struct drm_driver st7586_driver = {
 				  DRIVER_ATOMIC,
 	.fops			= &st7586_fops,
 	TINYDRM_GEM_DRIVER_OPS,
-	.lastclose		= tinydrm_lastclose,
+	.lastclose		= drm_fb_helper_lastclose,
 	.debugfs_init		= mipi_dbi_debugfs_init,
 	.name			= "st7586",
 	.desc			= "Sitronix ST7586",

include/drm/tinydrm/tinydrm.h

@@ -19,14 +19,12 @@
  * @drm: DRM device
  * @pipe: Display pipe structure
  * @dirty_lock: Serializes framebuffer flushing
- * @fbdev_cma: CMA fbdev structure
  * @fb_funcs: Framebuffer functions used when creating framebuffers
  */
 struct tinydrm_device {
 	struct drm_device *drm;
 	struct drm_simple_display_pipe pipe;
 	struct mutex dirty_lock;
-	struct drm_fbdev_cma *fbdev_cma;
 	const struct drm_framebuffer_funcs *fb_funcs;
 };
 
@@ -80,7 +78,6 @@ pipe_to_tinydrm(struct drm_simple_display_pipe *pipe)
 	.type = DRM_MODE_TYPE_DRIVER, \
 	.clock = 1 /* pass validation */
 
-void tinydrm_lastclose(struct drm_device *drm);
 void tinydrm_gem_cma_free_object(struct drm_gem_object *gem_obj);
 struct drm_gem_object *
 tinydrm_gem_cma_prime_import_sg_table(struct drm_device *drm,