Revert "drm/vkms: convert to use faux_device"

JIRA: https://issues.redhat.com/browse/RHEL-113577
Upstream Status: RHEL only

This reverts commit 5686601.

This commit was backported automatically as part of the DRM backport.

The faux bus is not available in this tree. Revert the change moving
the VKMS driver to this new bus.

NOTE: This commit does not compile due to missing RHEL-specific fix-ups,
which are split out into separate Git commits following this one.

If git bisect selected this commit, run "git bisect skip" and try again.
Repeat this until it selects a commit which compiles.

Signed-off-by: José Expósito <jexposit@redhat.com>

Author: jexposit

drivers/gpu/drm/vkms/vkms_drv.c

@@ -10,7 +10,7 @@
  */
 
 #include <linux/module.h>
-#include <linux/device/faux.h>
+#include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 
 #include <drm/clients/drm_client_setup.h>
@@ -149,27 +149,27 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
 static int vkms_create(struct vkms_config *config)
 {
 	int ret;
-	struct faux_device *fdev;
+	struct platform_device *pdev;
 	struct vkms_device *vkms_device;
 	const char *dev_name;
 
 	dev_name = vkms_config_get_device_name(config);
-	fdev = faux_device_create(dev_name, NULL, NULL);
-	if (!fdev)
-		return -ENODEV;
+	pdev = platform_device_register_simple(dev_name, -1, NULL, 0);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
 
-	if (!devres_open_group(&fdev->dev, NULL, GFP_KERNEL)) {
+	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
 		ret = -ENOMEM;
 		goto out_unregister;
 	}
 
-	vkms_device = devm_drm_dev_alloc(&fdev->dev, &vkms_driver,
+	vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
 					 struct vkms_device, drm);
 	if (IS_ERR(vkms_device)) {
 		ret = PTR_ERR(vkms_device);
 		goto out_devres;
 	}
-	vkms_device->faux_dev = fdev;
+	vkms_device->platform = pdev;
 	vkms_device->config = config;
 	config->dev = vkms_device;
 
@@ -203,9 +203,9 @@ static int vkms_create(struct vkms_config *config)
 	return 0;
 
 out_devres:
-	devres_release_group(&fdev->dev, NULL);
+	devres_release_group(&pdev->dev, NULL);
 out_unregister:
-	faux_device_destroy(fdev);
+	platform_device_unregister(pdev);
 	return ret;
 }
 
@@ -231,19 +231,19 @@ static int __init vkms_init(void)
 
 static void vkms_destroy(struct vkms_config *config)
 {
-	struct faux_device *fdev;
+	struct platform_device *pdev;
 
 	if (!config->dev) {
 		DRM_INFO("vkms_device is NULL.\n");
 		return;
 	}
 
-	fdev = config->dev->faux_dev;
+	pdev = config->dev->platform;
 
 	drm_dev_unregister(&config->dev->drm);
 	drm_atomic_helper_shutdown(&config->dev->drm);
-	devres_release_group(&fdev->dev, NULL);
-	faux_device_destroy(fdev);
+	devres_release_group(&pdev->dev, NULL);
+	platform_device_unregister(pdev);
 
 	config->dev = NULL;
 }

drivers/gpu/drm/vkms/vkms_drv.h

@@ -232,13 +232,13 @@ struct vkms_config;
  * struct vkms_device - Description of a VKMS device
  *
  * @drm - Base device in DRM
- * @faux_dev - Associated faux device
+ * @platform - Associated platform device
  * @output - Configuration and sub-components of the VKMS device
  * @config: Configuration used in this VKMS device
  */
 struct vkms_device {
 	struct drm_device drm;
-	struct faux_device *faux_dev;
+	struct platform_device *platform;
 	const struct vkms_config *config;
 };