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192.168.1.100 / T800 / 19f421ece02e978f016bb6ceca25d3d8846eeace / . / src / kernel / linux / v4.19 / drivers / usb / serial / aircable.c
blob: 84d52953dd0a1df9f60bb0c0d008269639cdbd62 [file] [log] [blame]
xjb04a4022021-11-25 15:01:52 +0800[diff] [blame]1// SPDX-License-Identifier: GPL-2.0
2/*
3 * AIRcable USB Bluetooth Dongle Driver.
4 *
5 * Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
6 * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
7 *
8 * The device works as an standard CDC device, it has 2 interfaces, the first
9 * one is for firmware access and the second is the serial one.
10 * The protocol is very simply, there are two possibilities reading or writing.
11 * When writing the first urb must have a Header that starts with 0x20 0x29 the
12 * next two bytes must say how much data will be sent.
13 * When reading the process is almost equal except that the header starts with
14 * 0x00 0x20.
15 *
16 * The device simply need some stuff to understand data coming from the usb
17 * buffer: The First and Second byte is used for a Header, the Third and Fourth
18 * tells the device the amount of information the package holds.
19 * Packages are 60 bytes long Header Stuff.
20 * When writing to the device the first two bytes of the header are 0x20 0x29
21 * When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
22 * situation, when too much data arrives to the device because it sends the data
23 * but with out the header. I will use a simply hack to override this situation,
24 * if there is data coming that does not contain any header, then that is data
25 * that must go directly to the tty, as there is no documentation about if there
26 * is any other control code, I will simply check for the first
27 * one.
28 *
29 * I have taken some info from a Greg Kroah-Hartman article:
30 * http://www.linuxjournal.com/article/6573
31 * And from Linux Device Driver Kit CD, which is a great work, the authors taken
32 * the work to recompile lots of information an knowledge in drivers development
33 * and made it all available inside a cd.
34 * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
35 *
36 */
37
38#include <asm/unaligned.h>
39#include <linux/tty.h>
40#include <linux/slab.h>
41#include <linux/module.h>
42#include <linux/tty_flip.h>
43#include <linux/usb.h>
44#include <linux/usb/serial.h>
45
46/* Vendor and Product ID */
47#define AIRCABLE_VID 0x16CA
48#define AIRCABLE_USB_PID 0x1502
49
50/* Protocol Stuff */
51#define HCI_HEADER_LENGTH 0x4
52#define TX_HEADER_0 0x20
53#define TX_HEADER_1 0x29
54#define RX_HEADER_0 0x00
55#define RX_HEADER_1 0x20
56#define HCI_COMPLETE_FRAME 64
57
58/* rx_flags */
59#define THROTTLED 0x01
60#define ACTUALLY_THROTTLED 0x02
61
62#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>, Johan Hovold <jhovold@gmail.com>"
63#define DRIVER_DESC "AIRcable USB Driver"
64
65/* ID table that will be registered with USB core */
66static const struct usb_device_id id_table[] = {
67 { USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
68 { },
69};
70MODULE_DEVICE_TABLE(usb, id_table);
71
72static int aircable_prepare_write_buffer(struct usb_serial_port *port,
73 void *dest, size_t size)
74{
75 int count;
76 unsigned char *buf = dest;
77
78 count = kfifo_out_locked(&port->write_fifo, buf + HCI_HEADER_LENGTH,
79 size - HCI_HEADER_LENGTH, &port->lock);
80 buf[0] = TX_HEADER_0;
81 buf[1] = TX_HEADER_1;
82 put_unaligned_le16(count, &buf[2]);
83
84 return count + HCI_HEADER_LENGTH;
85}
86
87static int aircable_calc_num_ports(struct usb_serial *serial,
88 struct usb_serial_endpoints *epds)
89{
90 /* Ignore the first interface, which has no bulk endpoints. */
91 if (epds->num_bulk_out == 0) {
92 dev_dbg(&serial->interface->dev,
93 "ignoring interface with no bulk-out endpoints\n");
94 return -ENODEV;
95 }
96
97 return 1;
98}
99
100static int aircable_process_packet(struct usb_serial_port *port,
101 int has_headers, char *packet, int len)
102{
103 if (has_headers) {
104 len -= HCI_HEADER_LENGTH;
105 packet += HCI_HEADER_LENGTH;
106 }
107 if (len <= 0) {
108 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
109 return 0;
110 }
111
112 tty_insert_flip_string(&port->port, packet, len);
113
114 return len;
115}
116
117static void aircable_process_read_urb(struct urb *urb)
118{
119 struct usb_serial_port *port = urb->context;
120 char *data = (char *)urb->transfer_buffer;
121 int has_headers;
122 int count;
123 int len;
124 int i;
125
126 has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0);
127
128 count = 0;
129 for (i = 0; i < urb->actual_length; i += HCI_COMPLETE_FRAME) {
130 len = min_t(int, urb->actual_length - i, HCI_COMPLETE_FRAME);
131 count += aircable_process_packet(port, has_headers,
132 &data[i], len);
133 }
134
135 if (count)
136 tty_flip_buffer_push(&port->port);
137}
138
139static struct usb_serial_driver aircable_device = {
140 .driver = {
141 .owner = THIS_MODULE,
142 .name = "aircable",
143 },
144 .id_table = id_table,
145 .bulk_out_size = HCI_COMPLETE_FRAME,
146 .calc_num_ports = aircable_calc_num_ports,
147 .process_read_urb = aircable_process_read_urb,
148 .prepare_write_buffer = aircable_prepare_write_buffer,
149 .throttle = usb_serial_generic_throttle,
150 .unthrottle = usb_serial_generic_unthrottle,
151};
152
153static struct usb_serial_driver * const serial_drivers[] = {
154 &aircable_device, NULL
155};
156
157module_usb_serial_driver(serial_drivers, id_table);
158
159MODULE_AUTHOR(DRIVER_AUTHOR);
160MODULE_DESCRIPTION(DRIVER_DESC);
161MODULE_LICENSE("GPL v2");