drm/exynos-drm: Run DRM default client setup

Rework fbdev probing to support fbdev_probe in struct drm_driver
and remove the old fb_probe callback. Provide an initializer macro
for struct drm_driver that sets the callback according to the kernel
configuration.

Call drm_client_setup() to run the kernel's default client setup
for DRM. Set fbdev_probe in struct drm_driver, so that the client
setup can start the common fbdev client.

The exynos-drm driver specifies a preferred color mode of 32. As this
is the default if no format has been given, leave it out entirely.

v5:
- select DRM_CLIENT_SELECTION
v4:
- revert an unrelated cleanup (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-75-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/exynos/Kconfig

@@ -4,6 +4,7 @@ config DRM_EXYNOS
 	depends on OF && DRM && COMMON_CLK
 	depends on ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
 	depends on MMU
+	select DRM_CLIENT_SELECTION
 	select DRM_DISPLAY_HELPER if DRM_EXYNOS_DP
 	select DRM_KMS_HELPER
 	select VIDEOMODE_HELPERS

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -15,6 +15,7 @@
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client_setup.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_fourcc.h>
@@ -111,6 +112,7 @@ static const struct drm_driver exynos_drm_driver = {
 	.dumb_create		= exynos_drm_gem_dumb_create,
 	.gem_prime_import	= exynos_drm_gem_prime_import,
 	.gem_prime_import_sg_table	= exynos_drm_gem_prime_import_sg_table,
+	EXYNOS_DRM_FBDEV_DRIVER_OPS,
 	.ioctls			= exynos_ioctls,
 	.num_ioctls		= ARRAY_SIZE(exynos_ioctls),
 	.fops			= &exynos_drm_driver_fops,
@@ -288,7 +290,7 @@ static int exynos_drm_bind(struct device *dev)
 	if (ret < 0)
 		goto err_cleanup_poll;
 
-	exynos_drm_fbdev_setup(drm);
+	drm_client_setup(drm, NULL);
 
 	return 0;
 

drivers/gpu/drm/exynos/exynos_drm_fbdev.c

@@ -23,7 +23,6 @@
 #include "exynos_drm_fbdev.h"
 
 #define MAX_CONNECTOR		4
-#define PREFERRED_BPP		32
 
 static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
@@ -87,8 +86,11 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 	return 0;
 }
 
-static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
-				    struct drm_fb_helper_surface_size *sizes)
+static const struct drm_fb_helper_funcs exynos_drm_fbdev_helper_funcs = {
+};
+
+int exynos_drm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
+					struct drm_fb_helper_surface_size *sizes)
 {
 	struct exynos_drm_gem *exynos_gem;
 	struct drm_device *dev = helper->dev;
@@ -120,6 +122,7 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 		ret = PTR_ERR(helper->fb);
 		goto err_destroy_gem;
 	}
+	helper->funcs = &exynos_drm_fbdev_helper_funcs;
 
 	ret = exynos_drm_fbdev_update(helper, sizes, exynos_gem);
 	if (ret < 0)
@@ -134,93 +137,3 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 	exynos_drm_gem_destroy(exynos_gem);
 	return ret;
 }
-
-static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
-	.fb_probe =	exynos_drm_fbdev_create,
-};
-
-/*
- * struct drm_client
- */
-
-static void exynos_drm_fbdev_client_unregister(struct drm_client_dev *client)
-{
-	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
-
-	if (fb_helper->info) {
-		drm_fb_helper_unregister_info(fb_helper);
-	} else {
-		drm_client_release(&fb_helper->client);
-		drm_fb_helper_unprepare(fb_helper);
-		kfree(fb_helper);
-	}
-}
-
-static int exynos_drm_fbdev_client_restore(struct drm_client_dev *client)
-{
-	drm_fb_helper_lastclose(client->dev);
-
-	return 0;
-}
-
-static int exynos_drm_fbdev_client_hotplug(struct drm_client_dev *client)
-{
-	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
-	struct drm_device *dev = client->dev;
-	int ret;
-
-	if (dev->fb_helper)
-		return drm_fb_helper_hotplug_event(dev->fb_helper);
-
-	ret = drm_fb_helper_init(dev, fb_helper);
-	if (ret)
-		goto err_drm_err;
-
-	if (!drm_drv_uses_atomic_modeset(dev))
-		drm_helper_disable_unused_functions(dev);
-
-	ret = drm_fb_helper_initial_config(fb_helper);
-	if (ret)
-		goto err_drm_fb_helper_fini;
-
-	return 0;
-
-err_drm_fb_helper_fini:
-	drm_fb_helper_fini(fb_helper);
-err_drm_err:
-	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
-	return ret;
-}
-
-static const struct drm_client_funcs exynos_drm_fbdev_client_funcs = {
-	.owner		= THIS_MODULE,
-	.unregister	= exynos_drm_fbdev_client_unregister,
-	.restore	= exynos_drm_fbdev_client_restore,
-	.hotplug	= exynos_drm_fbdev_client_hotplug,
-};
-
-void exynos_drm_fbdev_setup(struct drm_device *dev)
-{
-	struct drm_fb_helper *fb_helper;
-	int ret;
-
-	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
-	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
-
-	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
-	if (!fb_helper)
-		return;
-	drm_fb_helper_prepare(dev, fb_helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
-
-	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &exynos_drm_fbdev_client_funcs);
-	if (ret)
-		goto err_drm_client_init;
-
-	drm_client_register(&fb_helper->client);
-
-	return;
-
-err_drm_client_init:
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
-}

drivers/gpu/drm/exynos/exynos_drm_fbdev.h

@@ -11,12 +11,17 @@
 #ifndef _EXYNOS_DRM_FBDEV_H_
 #define _EXYNOS_DRM_FBDEV_H_
 
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-void exynos_drm_fbdev_setup(struct drm_device *dev);
+struct drm_fb_helper;
+struct drm_fb_helper_surface_size;
+
+#if defined(CONFIG_DRM_FBDEV_EMULATION)
+int exynos_drm_fbdev_driver_fbdev_probe(struct drm_fb_helper *fbh,
+					struct drm_fb_helper_surface_size *sizes);
+#define EXYNOS_DRM_FBDEV_DRIVER_OPS \
+	.fbdev_probe = exynos_drm_fbdev_driver_fbdev_probe
 #else
-static inline void exynos_drm_fbdev_setup(struct drm_device *dev)
-{
-}
+#define EXYNOS_DRM_FBDEV_DRIVER_OPS \
+	.fbdev_probe = NULL
 #endif
 
 #endif