[PATCH 18/21] drm/nouveau/nvkm: add device to auxiliary bus for each nvkm_device

[Ben Skeggs <bskeggs@xxxxxxxxxx>]

This commit registers a device on the aux bus after core NVKM init
has finished, which will be used by a later commit to have the DRM
driver probe() against an aux device instead of a PCI or platform
device (in the case of Tegra).

Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
---
 drivers/gpu/drm/nouveau/Kconfig               |  1 +
 .../drm/nouveau/include/nvkm/core/device.h    |  3 ++
 drivers/gpu/drm/nouveau/nvkm/device/base.c    | 33 +++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig
index 4c10b400658c..6d0d46a0e66f 100644
--- a/drivers/gpu/drm/nouveau/Kconfig
+++ b/drivers/gpu/drm/nouveau/Kconfig
@@ -7,6 +7,7 @@ config DRM_NOUVEAU
 	depends on DRM_DISPLAY_HELPER
 	depends on PCI
 	depends on MMU
+	select AUXILIARY_BUS
 	select IOMMU_API
 	select FW_LOADER
 	select DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/device.h b/drivers/gpu/drm/nouveau/include/nvkm/core/device.h
index d8596fe0adea..855d1b20820d 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/device.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/device.h
@@ -5,6 +5,8 @@
 #include <core/intr.h>
 enum nvkm_subdev_type;
 
+#include <linux/auxiliary_bus.h>
+
 enum nvkm_device_type {
 	NVKM_DEVICE_PCI,
 	NVKM_DEVICE_AGP,
@@ -78,6 +80,7 @@ struct nvkm_device {
 		bool legacy_done;
 	} intr;
 
+	struct auxiliary_device auxdev;
 	const struct nvif_driver_func *driver;
 };
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/device/base.c b/drivers/gpu/drm/nouveau/nvkm/device/base.c
index 4f8298bf71ee..fbb6e20bc1f2 100644
--- a/drivers/gpu/drm/nouveau/nvkm/device/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/device/base.c
@@ -3029,6 +3029,9 @@ nvkm_device_del(struct nvkm_device **pdevice)
 	struct nvkm_device *device = *pdevice;
 	struct nvkm_subdev *subdev, *subtmp;
 	if (device) {
+		auxiliary_device_delete(&device->auxdev);
+		auxiliary_device_uninit(&device->auxdev);
+
 		nvkm_intr_dtor(device);
 
 		list_for_each_entry_safe_reverse(subdev, subtmp, &device->subdev, head)
@@ -3076,6 +3079,16 @@ nvkm_device_endianness(struct nvkm_device *device)
 	return true;
 }
 
+static DEFINE_IDA(nvkm_device_id);
+
+static void
+nvkm_device_release(struct device *dev)
+{
+	struct nvkm_device *device = container_of(dev, typeof(*device), auxdev.dev);
+
+	ida_free(&nvkm_device_id, device->auxdev.id);
+}
+
 int
 nvkm_device_ctor(const struct nvkm_device_func *func,
 		 const struct nvkm_device_quirk *quirk,
@@ -3335,5 +3348,25 @@ nvkm_device_ctor(const struct nvkm_device_func *func,
 		iounmap(device->pri);
 		device->pri = NULL;
 	}
+
+	if (ret == 0) {
+		ret = ida_alloc(&nvkm_device_id, GFP_KERNEL);
+		if (ret < 0)
+			return ret;
+
+		device->auxdev.dev.parent = device->dev;
+		device->auxdev.dev.release = nvkm_device_release;
+		device->auxdev.name = "device";
+		device->auxdev.id = ret;
+
+		ret = auxiliary_device_init(&device->auxdev);
+		if (ret)
+			return ret;
+
+		ret = auxiliary_device_add(&device->auxdev);
+		if (ret)
+			auxiliary_device_uninit(&device->auxdev);
+	}
+
 	return ret;
 }
-- 
2.44.0