drm/vgem/vgem_drv convert to use faux_device

The vgem driver does not need to create a platform device, as there is
no real platform resources associated it,  it only did so because it was
simple to do that in order to get a device to use for resource
management of drm resources.  Change the driver to use the faux device
instead as this is NOT a real platform device.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/2025070114-iron-shiny-b92e@gregkh

diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index 2752ab4f1c97e379b0974f3041a8f6a361ebcf9e..260c647339725d6a0fe0b377059148893ab12c69 100644 (file)
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -32,7 +32,7 @@
 
 #include <linux/dma-buf.h>
 #include <linux/module.h>
-#include <linux/platform_device.h>
+#include <linux/device/faux.h>
 #include <linux/shmem_fs.h>
 #include <linux/vmalloc.h>
 
@@ -52,7 +52,7 @@
 
 static struct vgem_device {
        struct drm_device drm;
-       struct platform_device *platform;
+       struct faux_device *faux_dev;
 } *vgem_device;
 
 static int vgem_open(struct drm_device *dev, struct drm_file *file)
@@ -127,27 +127,27 @@ static const struct drm_driver vgem_driver = {
 static int __init vgem_init(void)
 {
        int ret;
-       struct platform_device *pdev;
+       struct faux_device *fdev;
 
-       pdev = platform_device_register_simple("vgem", -1, NULL, 0);
-       if (IS_ERR(pdev))
-               return PTR_ERR(pdev);
+       fdev = faux_device_create("vgem", NULL, NULL);
+       if (!fdev)
+               return -ENODEV;
 
-       if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
+       if (!devres_open_group(&fdev->dev, NULL, GFP_KERNEL)) {
                ret = -ENOMEM;
                goto out_unregister;
        }
 
-       dma_coerce_mask_and_coherent(&pdev->dev,
+       dma_coerce_mask_and_coherent(&fdev->dev,
                                     DMA_BIT_MASK(64));
 
-       vgem_device = devm_drm_dev_alloc(&pdev->dev, &vgem_driver,
+       vgem_device = devm_drm_dev_alloc(&fdev->dev, &vgem_driver,
                                         struct vgem_device, drm);
        if (IS_ERR(vgem_device)) {
                ret = PTR_ERR(vgem_device);
                goto out_devres;
        }
-       vgem_device->platform = pdev;
+       vgem_device->faux_dev = fdev;
 
        /* Final step: expose the device/driver to userspace */
        ret = drm_dev_register(&vgem_device->drm, 0);
@@ -157,19 +157,19 @@ static int __init vgem_init(void)
        return 0;
 
 out_devres:
-       devres_release_group(&pdev->dev, NULL);
+       devres_release_group(&fdev->dev, NULL);
 out_unregister:
-       platform_device_unregister(pdev);
+       faux_device_destroy(fdev);
        return ret;
 }
 
 static void __exit vgem_exit(void)
 {
-       struct platform_device *pdev = vgem_device->platform;
+       struct faux_device *fdev = vgem_device->faux_dev;
 
        drm_dev_unregister(&vgem_device->drm);
-       devres_release_group(&pdev->dev, NULL);
-       platform_device_unregister(pdev);
+       devres_release_group(&fdev->dev, NULL);
+       faux_device_destroy(fdev);
 }
 
 module_init(vgem_init);