drm/msm: 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 msm 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

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Sean Paul <sean@poorly.run>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-77-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/msm/Kconfig

@@ -14,6 +14,7 @@ config DRM_MSM
 	select IOMMU_IO_PGTABLE
 	select QCOM_MDT_LOADER if ARCH_QCOM
 	select REGULATOR
+	select DRM_CLIENT_SELECTION
 	select DRM_DISPLAY_DP_AUX_BUS
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER

drivers/gpu/drm/msm/msm_drv.c

@@ -10,6 +10,7 @@
 #include <linux/of_address.h>
 #include <linux/uaccess.h>
 
+#include <drm/drm_client_setup.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_ioctl.h>
@@ -292,7 +293,7 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
 
 	if (priv->kms_init) {
 		drm_kms_helper_poll_init(ddev);
-		msm_fbdev_setup(ddev);
+		drm_client_setup(ddev, NULL);
 	}
 
 	return 0;
@@ -903,6 +904,7 @@ static const struct drm_driver msm_driver = {
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init       = msm_debugfs_init,
 #endif
+	MSM_FBDEV_DRIVER_OPS,
 	.show_fdinfo        = msm_show_fdinfo,
 	.ioctls             = msm_ioctls,
 	.num_ioctls         = ARRAY_SIZE(msm_ioctls),

drivers/gpu/drm/msm/msm_drv.h

@@ -40,6 +40,9 @@ extern struct fault_attr fail_gem_iova;
 #  define should_fail(attr, size) 0
 #endif
 
+struct drm_fb_helper;
+struct drm_fb_helper_surface_size;
+
 struct msm_kms;
 struct msm_gpu;
 struct msm_mmu;
@@ -294,11 +297,13 @@ struct drm_framebuffer * msm_alloc_stolen_fb(struct drm_device *dev,
 		int w, int h, int p, uint32_t format);
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-void msm_fbdev_setup(struct drm_device *dev);
+int msm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
+				 struct drm_fb_helper_surface_size *sizes);
+#define MSM_FBDEV_DRIVER_OPS \
+	.fbdev_probe = msm_fbdev_driver_fbdev_probe
 #else
-static inline void msm_fbdev_setup(struct drm_device *dev)
-{
-}
+#define MSM_FBDEV_DRIVER_OPS \
+	.fbdev_probe = NULL
 #endif
 
 struct hdmi;

drivers/gpu/drm/msm/msm_fbdev.c

@@ -65,8 +65,31 @@ static const struct fb_ops msm_fb_ops = {
 	.fb_destroy = msm_fbdev_fb_destroy,
 };
 
-static int msm_fbdev_create(struct drm_fb_helper *helper,
-		struct drm_fb_helper_surface_size *sizes)
+static int msm_fbdev_fb_dirty(struct drm_fb_helper *helper,
+			      struct drm_clip_rect *clip)
+{
+	struct drm_device *dev = helper->dev;
+	int ret;
+
+	/* Call damage handlers only if necessary */
+	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
+		return 0;
+
+	if (helper->fb->funcs->dirty) {
+		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
+		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct drm_fb_helper_funcs msm_fbdev_helper_funcs = {
+	.fb_dirty = msm_fbdev_fb_dirty,
+};
+
+int msm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
+				 struct drm_fb_helper_surface_size *sizes)
 {
 	struct drm_device *dev = helper->dev;
 	struct msm_drm_private *priv = dev->dev_private;
@@ -114,6 +137,7 @@ static int msm_fbdev_create(struct drm_fb_helper *helper,
 
 	DBG("fbi=%p, dev=%p", fbi, dev);
 
+	helper->funcs = &msm_fbdev_helper_funcs;
 	helper->fb = fb;
 
 	fbi->fbops = &msm_fb_ops;
@@ -138,119 +162,3 @@ static int msm_fbdev_create(struct drm_fb_helper *helper,
 	drm_framebuffer_remove(fb);
 	return ret;
 }
-
-static int msm_fbdev_fb_dirty(struct drm_fb_helper *helper,
-			      struct drm_clip_rect *clip)
-{
-	struct drm_device *dev = helper->dev;
-	int ret;
-
-	/* Call damage handlers only if necessary */
-	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
-		return 0;
-
-	if (helper->fb->funcs->dirty) {
-		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
-		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
-			return ret;
-	}
-
-	return 0;
-}
-
-static const struct drm_fb_helper_funcs msm_fb_helper_funcs = {
-	.fb_probe = msm_fbdev_create,
-	.fb_dirty = msm_fbdev_fb_dirty,
-};
-
-/*
- * struct drm_client
- */
-
-static void msm_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 msm_fbdev_client_restore(struct drm_client_dev *client)
-{
-	drm_fb_helper_lastclose(client->dev);
-
-	return 0;
-}
-
-static int msm_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 msm_fbdev_client_funcs = {
-	.owner		= THIS_MODULE,
-	.unregister	= msm_fbdev_client_unregister,
-	.restore	= msm_fbdev_client_restore,
-	.hotplug	= msm_fbdev_client_hotplug,
-};
-
-/* initialize fbdev helper */
-void msm_fbdev_setup(struct drm_device *dev)
-{
-	struct drm_fb_helper *helper;
-	int ret;
-
-	if (!fbdev)
-		return;
-
-	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
-	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
-
-	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
-	if (!helper)
-		return;
-	drm_fb_helper_prepare(dev, helper, 32, &msm_fb_helper_funcs);
-
-	ret = drm_client_init(dev, &helper->client, "fbdev", &msm_fbdev_client_funcs);
-	if (ret) {
-		drm_err(dev, "Failed to register client: %d\n", ret);
-		goto err_drm_fb_helper_unprepare;
-	}
-
-	drm_client_register(&helper->client);
-
-	return;
-
-err_drm_fb_helper_unprepare:
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
-}