blob: 26e0ee2a9609398b700518122fbad0891013d204 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
*************
Bluetooth HCI
*************
Role: device only. This driver transports Bluetooth HCI commands, events, and
ACL data over USB. It does not implement a Bluetooth controller, Link Manager,
or host stack; the application must provide that functionality.
Configuration and descriptors
=============================
Enable ``CFG_TUD_BTH`` and use ``TUD_BTH_DESCRIPTOR`` in the configuration
descriptor.
.. list-table::
:header-rows: 1
:widths: 38 17 45
* - Option
- Default
- What it controls
* - ``CFG_TUD_BTH_ISO_ALT_COUNT``
- Required
- Number of isochronous voice alternate settings. Pass one paired
IN/OUT packet size per setting to ``TUD_BTH_DESCRIPTOR``.
* - ``CFG_TUD_BTH_EVENT_EPSIZE``
- ``16`` bytes
- Maximum HCI event interrupt-IN packet.
* - ``CFG_TUD_BTH_DATA_EPSIZE``
- ``64`` bytes
- ACL bulk endpoint packet size. Keep it consistent with the descriptor
and active bus speed.
* - ``CFG_TUD_BTH_HISTORICAL_COMPATIBLE``
- ``0``
- Uses the legacy HCI command request value required by some historical
controller implementations.
Set ``CFG_TUD_BTH_HISTORICAL_COMPATIBLE`` only for a controller that requires
the legacy ``bRequest = 0xe0`` behavior described by the Bluetooth Core
specification. It is not a general compatibility switch.
Data path
=========
.. list-table::
:header-rows: 1
:widths: 38 62
* - API or callback
- What it does
* - ``tud_bt_hci_cmd_cb()``
- Delivers one host HCI command to the controller implementation.
* - ``tud_bt_acl_data_received_cb()``
- Delivers received host-to-controller ACL bytes.
* - ``tud_bt_event_send()``
- Queues a controller-to-host HCI event; ``false`` means it was not
accepted.
* - ``tud_bt_acl_data_send()``
- Queues controller-to-host ACL data; ``false`` means it was not accepted.
* - ``tud_bt_event_sent_cb()`` /
``tud_bt_acl_data_sent_cb()``
- Reports completion and releases the corresponding application-owned
send buffer.
The host delivers HCI commands through ``tud_bt_hci_cmd_cb()`` and ACL data
through ``tud_bt_acl_data_received_cb()``. The controller sends HCI events with
``tud_bt_event_send()`` and ACL data with ``tud_bt_acl_data_send()``.
The send APIs do not copy the whole packet. Keep each buffer valid and
unchanged until ``tud_bt_event_sent_cb()`` or ``tud_bt_acl_data_sent_cb()``.
Check the boolean return value before considering a packet queued.
There is currently no dedicated Bluetooth device example. Use the public API
in ``src/class/bth/bth_device.h`` together with the Bluetooth Core USB
Transport and HCI packet formats.
|
