1.. SPDX-License-Identifier: GPL-2.0
2
3===============================================
4TEE (Trusted Execution Environment) driver API
5===============================================
6
7Kernel provides a TEE bus infrastructure where a Trusted Application is
8represented as a device identified via Universally Unique Identifier (UUID) and
9client drivers register a table of supported device UUIDs.
10
11TEE bus infrastructure registers following APIs:
12
13match():
14  iterates over the client driver UUID table to find a corresponding
15  match for device UUID. If a match is found, then this particular device is
16  probed via corresponding probe API registered by the client driver. This
17  process happens whenever a device or a client driver is registered with TEE
18  bus.
19
20uevent():
21  notifies user-space (udev) whenever a new device is registered on
22  TEE bus for auto-loading of modularized client drivers.
23
24TEE bus device enumeration is specific to underlying TEE implementation, so it
25is left open for TEE drivers to provide corresponding implementation.
26
27Then TEE client driver can talk to a matched Trusted Application using APIs
28listed in include/linux/tee_drv.h.
29
30TEE client driver example
31-------------------------
32
33Suppose a TEE client driver needs to communicate with a Trusted Application
34having UUID: ``ac6a4085-0e82-4c33-bf98-8eb8e118b6c2``, so driver registration
35snippet would look like::
36
37	static const struct tee_client_device_id client_id_table[] = {
38		{UUID_INIT(0xac6a4085, 0x0e82, 0x4c33,
39			   0xbf, 0x98, 0x8e, 0xb8, 0xe1, 0x18, 0xb6, 0xc2)},
40		{}
41	};
42
43	MODULE_DEVICE_TABLE(tee, client_id_table);
44
45	static struct tee_client_driver client_driver = {
46		.id_table	= client_id_table,
47		.driver		= {
48			.name		= DRIVER_NAME,
49			.bus		= &tee_bus_type,
50			.probe		= client_probe,
51			.remove		= client_remove,
52		},
53	};
54
55	static int __init client_init(void)
56	{
57		return driver_register(&client_driver.driver);
58	}
59
60	static void __exit client_exit(void)
61	{
62		driver_unregister(&client_driver.driver);
63	}
64
65	module_init(client_init);
66	module_exit(client_exit);
67