drm/mgag200: Embed instance of struct drm_device in struct mga_device

Following current best practice, the instance of struct drm_device is now
embedded in struct mga_device. The respective field has been renamed from
'dev' to 'base' to reflect the relationship. Conversion from DRM device is
done via upcast. Using dev_private is no longer possible.

The patch also open-codes drm_dev_alloc() and DRM device initialization
is now performed by a call to drm_device_init().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200605135803.19811-14-tzimmermann@suse.de

drivers/gpu/drm/mgag200/mgag200_drv.c

@@ -45,7 +45,7 @@ static struct drm_driver mgag200_driver = {
 
 static int mgag200_device_init(struct mga_device *mdev, unsigned long flags)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	int ret, option;
 
 	mdev->flags = mgag200_flags_from_driver_data(flags);
@@ -89,25 +89,24 @@ static int mgag200_device_init(struct mga_device *mdev, unsigned long flags)
 }
 
 static struct mga_device *
-mgag200_driver_load(struct pci_dev *pdev, unsigned long flags)
+mgag200_device_create(struct pci_dev *pdev, unsigned long flags)
 {
 	struct drm_device *dev;
 	struct mga_device *mdev;
 	int ret;
 
-	dev = drm_dev_alloc(&mgag200_driver, &pdev->dev);
-	if (IS_ERR(dev))
-		return ERR_CAST(dev);
+	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return ERR_PTR(-ENOMEM);
+	dev = &mdev->base;
+
+	ret = drm_dev_init(dev, &mgag200_driver, &pdev->dev);
+	if (ret)
+		return ERR_PTR(ret);
 
 	dev->pdev = pdev;
 	pci_set_drvdata(pdev, dev);
 
-	mdev = devm_kzalloc(dev->dev, sizeof(struct mga_device), GFP_KERNEL);
-	if (mdev == NULL)
-		return ERR_PTR(-ENOMEM);
-	dev->dev_private = (void *)mdev;
-	mdev->dev = dev;
-
 	ret = mgag200_device_init(mdev, flags);
 	if (ret)
 		goto err_drm_dev_put;
@@ -116,19 +115,9 @@ mgag200_driver_load(struct pci_dev *pdev, unsigned long flags)
 
 err_drm_dev_put:
 	drm_dev_put(dev);
-	dev->dev_private = NULL;
 	return ERR_PTR(ret);
 }
 
-static void mgag200_driver_unload(struct drm_device *dev)
-{
-	struct mga_device *mdev = to_mga_device(dev);
-
-	if (mdev == NULL)
-		return;
-	dev->dev_private = NULL;
-}
-
 /*
  * PCI driver
  */
@@ -161,21 +150,22 @@ mgag200_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		return ret;
 
-	mdev = mgag200_driver_load(pdev, ent->driver_data);
-	if (IS_ERR(mdev))
-		return PTR_ERR(mdev);
-	dev = mdev->dev;
+	mdev = mgag200_device_create(pdev, ent->driver_data);
+	if (IS_ERR(mdev)) {
+		ret = PTR_ERR(mdev);
+		goto err_drm_dev_put;
+	}
+	dev = &mdev->base;
 
 	ret = drm_dev_register(dev, ent->driver_data);
 	if (ret)
-		goto err_mgag200_driver_unload;
+		goto err_drm_dev_put;
 
 	drm_fbdev_generic_setup(dev, 0);
 
 	return 0;
 
-err_mgag200_driver_unload:
-	mgag200_driver_unload(dev);
+err_drm_dev_put:
 	drm_dev_put(dev);
 	return ret;
 }
@@ -185,7 +175,6 @@ static void mgag200_pci_remove(struct pci_dev *pdev)
 	struct drm_device *dev = pci_get_drvdata(pdev);
 
 	drm_dev_unregister(dev);
-	mgag200_driver_unload(dev);
 	drm_dev_put(dev);
 }
 

drivers/gpu/drm/mgag200/mgag200_drv.h

@@ -142,7 +142,7 @@ enum mga_type {
 #define IS_G200_SE(mdev) (mdev->type == G200_SE_A || mdev->type == G200_SE_B)
 
 struct mga_device {
-	struct drm_device		*dev;
+	struct drm_device		base;
 	unsigned long			flags;
 
 	resource_size_t			rmmio_base;
@@ -170,7 +170,7 @@ struct mga_device {
 
 static inline struct mga_device *to_mga_device(struct drm_device *dev)
 {
-	return dev->dev_private;
+	return container_of(dev, struct mga_device, base);
 }
 
 static inline enum mga_type

drivers/gpu/drm/mgag200/mgag200_mm.c

@@ -89,7 +89,7 @@ static void mgag200_mm_release(struct drm_device *dev, void *ptr)
 
 int mgag200_mm_init(struct mga_device *mdev)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	resource_size_t start, len;
 	int ret;
 

drivers/gpu/drm/mgag200/mgag200_mode.c

@@ -854,7 +854,7 @@ static void mga_g200wb_commit(struct drm_crtc *crtc)
 static void mgag200_set_startadd(struct mga_device *mdev,
 				 unsigned long offset)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	u32 startadd;
 	u8 crtcc, crtcd, crtcext0;
 
@@ -882,7 +882,7 @@ static void mgag200_set_startadd(struct mga_device *mdev,
 static void mgag200_set_pci_regs(struct mga_device *mdev)
 {
 	uint32_t option = 0, option2 = 0;
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 
 	switch (mdev->type) {
 	case G200_SE_A:
@@ -1153,7 +1153,7 @@ static void mgag200_set_offset(struct mga_device *mdev,
 static void mgag200_set_format_regs(struct mga_device *mdev,
 				    const struct drm_framebuffer *fb)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	const struct drm_format_info *format = fb->format;
 	unsigned int bpp, bppshift, scale;
 	u8 crtcext3, xmulctrl;
@@ -1537,7 +1537,7 @@ static const struct drm_connector_funcs mga_vga_connector_funcs = {
 
 static int mgag200_vga_connector_init(struct mga_device *mdev)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	struct mga_connector *mconnector = &mdev->connector;
 	struct drm_connector *connector = &mconnector->base;
 	struct mga_i2c_chan *i2c;
@@ -1579,7 +1579,7 @@ static void
 mgag200_handle_damage(struct mga_device *mdev, struct drm_framebuffer *fb,
 		      struct drm_rect *clip)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	void *vmap;
 
 	vmap = drm_gem_shmem_vmap(fb->obj[0]);
@@ -1718,7 +1718,7 @@ static unsigned int mgag200_preferred_depth(struct mga_device *mdev)
 
 int mgag200_modeset_init(struct mga_device *mdev)
 {
-	struct drm_device *dev = mdev->dev;
+	struct drm_device *dev = &mdev->base;
 	struct drm_connector *connector = &mdev->connector.base;
 	struct drm_simple_display_pipe *pipe = &mdev->display_pipe;
 	size_t format_count = ARRAY_SIZE(mgag200_simple_display_pipe_formats);