Merge tag 'exynos-drm-next-for-v6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-nextdrm-next-2023-04-24

A patch series for implementing fbdev emulation as in-kernel client.

- This patch series refactors fbdev callbacks to DRM client functions and
  simplifies fbdev emulation initialization including some code cleanups.
  The changes make fbdev emulation behave like a regular DRM client.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Inki Dae <inki.dae@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230417100624.35229-1-inki.dae@samsung.com

5 files changed, 94 insertions, 117 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 16c539657f73..6b73fb7a83c3 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -16,7 +16,6 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_file.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_ioctl.h>
@@ -108,7 +107,6 @@ static const struct drm_driver exynos_drm_driver = {
 	.driver_features	= DRIVER_MODESET | DRIVER_GEM
 				  | DRIVER_ATOMIC | DRIVER_RENDER,
 	.open			= exynos_drm_open,
-	.lastclose		= drm_fb_helper_lastclose,
 	.postclose		= exynos_drm_postclose,
 	.dumb_create		= exynos_drm_gem_dumb_create,
 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
@@ -288,19 +286,15 @@ static int exynos_drm_bind(struct device *dev)
 	/* init kms poll for handling hpd */
 	drm_kms_helper_poll_init(drm);
 
-	ret = exynos_drm_fbdev_init(drm);
-	if (ret)
-		goto err_cleanup_poll;
-
 	/* register the DRM device */
 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)
-		goto err_cleanup_fbdev;
+		goto err_cleanup_poll;
+
+	exynos_drm_fbdev_setup(drm);
 
 	return 0;
 
-err_cleanup_fbdev:
-	exynos_drm_fbdev_fini(drm);
 err_cleanup_poll:
 	drm_kms_helper_poll_fini(drm);
 err_unbind_all:
@@ -321,7 +315,6 @@ static void exynos_drm_unbind(struct device *dev)
 
 	drm_dev_unregister(drm);
 
-	exynos_drm_fbdev_fini(drm);
 	drm_kms_helper_poll_fini(drm);
 
 	component_unbind_all(drm->dev, drm);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 6ae9056e7a18..81d501efd013 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -197,8 +197,6 @@ struct drm_exynos_file_private {
  * @wait: wait an atomic commit to finish
  */
 struct exynos_drm_private {
-	struct drm_fb_helper *fb_helper;
-
 	struct device *g2d_dev;
 	struct device *dma_dev;
 	void *mapping;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
index 97f2dee2db29..fc1c5608db96 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
@@ -11,7 +11,6 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -157,7 +156,6 @@ static struct drm_mode_config_helper_funcs exynos_drm_mode_config_helpers = {
 
 static const struct drm_mode_config_funcs exynos_drm_mode_config_funcs = {
 	.fb_create = exynos_user_fb_create,
-	.output_poll_changed = drm_fb_helper_output_poll_changed,
 	.atomic_check = drm_atomic_helper_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 4929ffe5a09a..ea4b3d248aac 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -8,16 +8,12 @@
  *	Seung-Woo Kim <sw0312.kim@samsung.com>
  */
 
-#include <linux/console.h>
-#include <linux/dma-mapping.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_fb_helper.h>
-#include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_prime.h>
-#include <drm/drm_probe_helper.h>
 #include <drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
@@ -27,22 +23,26 @@
 #define MAX_CONNECTOR		4
 #define PREFERRED_BPP		32
 
-#define to_exynos_fbdev(x)	container_of(x, struct exynos_drm_fbdev,\
-				drm_fb_helper)
+static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct drm_fb_helper *helper = info->par;
+	struct drm_gem_object *obj = drm_gem_fb_get_obj(helper->fb, 0);
 
-struct exynos_drm_fbdev {
-	struct drm_fb_helper	drm_fb_helper;
-	struct exynos_drm_gem	*exynos_gem;
-};
+	return drm_gem_prime_mmap(obj, vma);
+}
 
-static int exynos_drm_fb_mmap(struct fb_info *info,
-			struct vm_area_struct *vma)
+static void exynos_drm_fb_destroy(struct fb_info *info)
 {
-	struct drm_fb_helper *helper = info->par;
-	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper);
-	struct exynos_drm_gem *exynos_gem = exynos_fbd->exynos_gem;
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_framebuffer *fb = fb_helper->fb;
+
+	drm_fb_helper_fini(fb_helper);
 
-	return drm_gem_prime_mmap(&exynos_gem->base, vma);
+	drm_framebuffer_remove(fb);
+
+	drm_client_release(&fb_helper->client);
+	drm_fb_helper_unprepare(fb_helper);
+	kfree(fb_helper);
 }
 
 static const struct fb_ops exynos_drm_fb_ops = {
@@ -54,6 +54,7 @@ static const struct fb_ops exynos_drm_fb_ops = {
 	.fb_fillrect	= drm_fb_helper_cfb_fillrect,
 	.fb_copyarea	= drm_fb_helper_cfb_copyarea,
 	.fb_imageblit	= drm_fb_helper_cfb_imageblit,
+	.fb_destroy	= exynos_drm_fb_destroy,
 };
 
 static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
@@ -89,7 +90,6 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 				    struct drm_fb_helper_surface_size *sizes)
 {
-	struct exynos_drm_fbdev *exynos_fbdev = to_exynos_fbdev(helper);
 	struct exynos_drm_gem *exynos_gem;
 	struct drm_device *dev = helper->dev;
 	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
@@ -113,8 +113,6 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 	if (IS_ERR(exynos_gem))
 		return PTR_ERR(exynos_gem);
 
-	exynos_fbdev->exynos_gem = exynos_gem;
-
 	helper->fb =
 		exynos_drm_framebuffer_init(dev, &mode_cmd, &exynos_gem, 1);
 	if (IS_ERR(helper->fb)) {
@@ -127,19 +125,13 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 	if (ret < 0)
 		goto err_destroy_framebuffer;
 
-	return ret;
+	return 0;
 
 err_destroy_framebuffer:
 	drm_framebuffer_cleanup(helper->fb);
+	helper->fb = NULL;
 err_destroy_gem:
 	exynos_drm_gem_destroy(exynos_gem);
-
-	/*
-	 * if failed, all resources allocated above would be released by
-	 * drm_mode_config_cleanup() when drm_load() had been called prior
-	 * to any specific driver such as fimd or hdmi driver.
-	 */
-
 	return ret;
 }
 
@@ -147,80 +139,92 @@ static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
 	.fb_probe =	exynos_drm_fbdev_create,
 };
 
-int exynos_drm_fbdev_init(struct drm_device *dev)
+/*
+ * struct drm_client
+ */
+
+static void exynos_drm_fbdev_client_unregister(struct drm_client_dev *client)
 {
-	struct exynos_drm_fbdev *fbdev;
-	struct exynos_drm_private *private = dev->dev_private;
-	struct drm_fb_helper *helper;
-	int ret;
+	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);
 
-	if (!dev->mode_config.num_crtc)
-		return 0;
+	return 0;
+}
 
-	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
-	if (!fbdev)
-		return -ENOMEM;
+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;
 
-	private->fb_helper = helper = &fbdev->drm_fb_helper;
+	if (dev->fb_helper)
+		return drm_fb_helper_hotplug_event(dev->fb_helper);
 
-	drm_fb_helper_prepare(dev, helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
+	ret = drm_fb_helper_init(dev, fb_helper);
+	if (ret)
+		goto err_drm_err;
 
-	ret = drm_fb_helper_init(dev, helper);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev,
-			      "failed to initialize drm fb helper.\n");
-		goto err_init;
-	}
+	if (!drm_drv_uses_atomic_modeset(dev))
+		drm_helper_disable_unused_functions(dev);
 
-	ret = drm_fb_helper_initial_config(helper);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev,
-			      "failed to set up hw configuration.\n");
-		goto err_setup;
-	}
+	ret = drm_fb_helper_initial_config(fb_helper);
+	if (ret)
+		goto err_drm_fb_helper_fini;
 
 	return 0;
 
-err_setup:
-	drm_fb_helper_fini(helper);
-err_init:
-	drm_fb_helper_unprepare(helper);
-	private->fb_helper = NULL;
-	kfree(fbdev);
-
+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 void exynos_drm_fbdev_destroy(struct drm_device *dev,
-				      struct drm_fb_helper *fb_helper)
+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_framebuffer *fb;
+	struct drm_fb_helper *fb_helper;
+	int ret;
 
-	/* release drm framebuffer and real buffer */
-	if (fb_helper->fb && fb_helper->fb->funcs) {
-		fb = fb_helper->fb;
-		if (fb)
-			drm_framebuffer_remove(fb);
-	}
+	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
+	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 
-	drm_fb_helper_unregister_info(fb_helper);
+	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);
 
-	drm_fb_helper_fini(fb_helper);
-}
+	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &exynos_drm_fbdev_client_funcs);
+	if (ret)
+		goto err_drm_client_init;
 
-void exynos_drm_fbdev_fini(struct drm_device *dev)
-{
-	struct exynos_drm_private *private = dev->dev_private;
-	struct exynos_drm_fbdev *fbdev;
+	ret = exynos_drm_fbdev_client_hotplug(&fb_helper->client);
+	if (ret)
+		drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
 
-	if (!private || !private->fb_helper)
-		return;
+	drm_client_register(&fb_helper->client);
 
-	fbdev = to_exynos_fbdev(private->fb_helper);
+	return;
 
-	exynos_drm_fbdev_destroy(dev, private->fb_helper);
-	drm_fb_helper_unprepare(private->fb_helper);
-	kfree(fbdev);
-	private->fb_helper = NULL;
+err_drm_client_init:
+	drm_fb_helper_unprepare(fb_helper);
+	kfree(fb_helper);
 }
-
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.h b/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
index 3b1e98e84580..1e1dea627cd9 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
@@ -12,27 +12,11 @@
 #define _EXYNOS_DRM_FBDEV_H_
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-
-int exynos_drm_fbdev_init(struct drm_device *dev);
-void exynos_drm_fbdev_fini(struct drm_device *dev);
-
+void exynos_drm_fbdev_setup(struct drm_device *dev);
 #else
-
-static inline int exynos_drm_fbdev_init(struct drm_device *dev)
-{
-	return 0;
-}
-
-static inline void exynos_drm_fbdev_fini(struct drm_device *dev)
+static inline void exynos_drm_fbdev_setup(struct drm_device *dev)
 {
 }
-
-static inline void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
-{
-}
-
-#define exynos_drm_output_poll_changed (NULL)
-
 #endif
 
 #endif