1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Mediated device definition
4 *
5 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
6 *     Author: Neo Jia <cjia@nvidia.com>
7 *             Kirti Wankhede <kwankhede@nvidia.com>
8 */
9
10#ifndef MDEV_H
11#define MDEV_H
12
13#include <linux/device.h>
14#include <linux/uuid.h>
15
16struct mdev_type;
17
18struct mdev_device {
19	struct device dev;
20	guid_t uuid;
21	struct list_head next;
22	struct mdev_type *type;
23	bool active;
24};
25
26struct mdev_type {
27	/* set by the driver before calling mdev_register parent: */
28	const char *sysfs_name;
29	const char *pretty_name;
30
31	/* set by the core, can be used drivers */
32	struct mdev_parent *parent;
33
34	/* internal only */
35	struct kobject kobj;
36	struct kobject *devices_kobj;
37};
38
39/* embedded into the struct device that the mdev devices hang off */
40struct mdev_parent {
41	struct device *dev;
42	struct mdev_driver *mdev_driver;
43	struct kset *mdev_types_kset;
44	/* Synchronize device creation/removal with parent unregistration */
45	struct rw_semaphore unreg_sem;
46	struct mdev_type **types;
47	unsigned int nr_types;
48	atomic_t available_instances;
49};
50
51static inline struct mdev_device *to_mdev_device(struct device *dev)
52{
53	return container_of(dev, struct mdev_device, dev);
54}
55
56/**
57 * struct mdev_driver - Mediated device driver
58 * @device_api: string to return for the device_api sysfs
59 * @max_instances: maximum number of instances supported (optional)
60 * @probe: called when new device created
61 * @remove: called when device removed
62 * @get_available: Return the max number of instances that can be created
63 * @show_description: Print a description of the mtype
64 * @driver: device driver structure
65 **/
66struct mdev_driver {
67	const char *device_api;
68	unsigned int max_instances;
69	int (*probe)(struct mdev_device *dev);
70	void (*remove)(struct mdev_device *dev);
71	unsigned int (*get_available)(struct mdev_type *mtype);
72	ssize_t (*show_description)(struct mdev_type *mtype, char *buf);
73	struct device_driver driver;
74};
75
76int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
77		struct mdev_driver *mdev_driver, struct mdev_type **types,
78		unsigned int nr_types);
79void mdev_unregister_parent(struct mdev_parent *parent);
80
81int mdev_register_driver(struct mdev_driver *drv);
82void mdev_unregister_driver(struct mdev_driver *drv);
83
84static inline struct device *mdev_dev(struct mdev_device *mdev)
85{
86	return &mdev->dev;
87}
88
89#endif /* MDEV_H */
90