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-rw-r--r--include/linux/device/faux.h69
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diff --git a/include/linux/device/faux.h b/include/linux/device/faux.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2025 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (c) 2025 The Linux Foundation
+ *
+ * A "simple" faux bus that allows devices to be created and added
+ * automatically to it. This is to be used whenever you need to create a
+ * device that is not associated with any "real" system resources, and do
+ * not want to have to deal with a bus/driver binding logic. It is
+ * intended to be very simple, with only a create and a destroy function
+ * available.
+ */
+#ifndef _FAUX_DEVICE_H_
+#define _FAUX_DEVICE_H_
+
+#include <linux/container_of.h>
+#include <linux/device.h>
+
+/**
+ * struct faux_device - a "faux" device
+ * @dev: internal struct device of the object
+ *
+ * A simple faux device that can be created/destroyed. To be used when a
+ * driver only needs to have a device to "hang" something off. This can be
+ * used for downloading firmware or other basic tasks. Use this instead of
+ * a struct platform_device if the device has no resources assigned to
+ * it at all.
+ */
+struct faux_device {
+ struct device dev;
+};
+#define to_faux_device(x) container_of_const((x), struct faux_device, dev)
+
+/**
+ * struct faux_device_ops - a set of callbacks for a struct faux_device
+ * @probe: called when a faux device is probed by the driver core
+ * before the device is fully bound to the internal faux bus
+ * code. If probe succeeds, return 0, otherwise return a
+ * negative error number to stop the probe sequence from
+ * succeeding.
+ * @remove: called when a faux device is removed from the system
+ *
+ * Both @probe and @remove are optional, if not needed, set to NULL.
+ */
+struct faux_device_ops {
+ int (*probe)(struct faux_device *faux_dev);
+ void (*remove)(struct faux_device *faux_dev);
+};
+
+struct faux_device *faux_device_create(const char *name,
+ struct device *parent,
+ const struct faux_device_ops *faux_ops);
+struct faux_device *faux_device_create_with_groups(const char *name,
+ struct device *parent,
+ const struct faux_device_ops *faux_ops,
+ const struct attribute_group **groups);
+void faux_device_destroy(struct faux_device *faux_dev);
+
+static inline void *faux_device_get_drvdata(const struct faux_device *faux_dev)
+{
+ return dev_get_drvdata(&faux_dev->dev);
+}
+
+static inline void faux_device_set_drvdata(struct faux_device *faux_dev, void *data)
+{
+ dev_set_drvdata(&faux_dev->dev, data);
+}
+
+#endif /* _FAUX_DEVICE_H_ */