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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 <linux/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 = 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 .name = "aircable",
142 },
143 .id_table = id_table,
144 .bulk_out_size = HCI_COMPLETE_FRAME,
145 .calc_num_ports = aircable_calc_num_ports,
146 .process_read_urb = aircable_process_read_urb,
147 .prepare_write_buffer = aircable_prepare_write_buffer,
148 .throttle = usb_serial_generic_throttle,
149 .unthrottle = usb_serial_generic_unthrottle,
150};
151
152static struct usb_serial_driver * const serial_drivers[] = {
153 &aircable_device, NULL
154};
155
156module_usb_serial_driver(serial_drivers, id_table);
157
158MODULE_AUTHOR(DRIVER_AUTHOR);
159MODULE_DESCRIPTION(DRIVER_DESC);
160MODULE_LICENSE("GPL v2");
1/*
2 * AIRcable USB Bluetooth Dongle Driver.
3 *
4 * Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
5 * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
6 *
7 * This program is free software; you can redistribute it and/or modify it under
8 * the terms of the GNU General Public License version 2 as published by the
9 * Free Software Foundation.
10 *
11 * The device works as an standard CDC device, it has 2 interfaces, the first
12 * one is for firmware access and the second is the serial one.
13 * The protocol is very simply, there are two posibilities reading or writing.
14 * When writing the first urb must have a Header that starts with 0x20 0x29 the
15 * next two bytes must say how much data will be sended.
16 * When reading the process is almost equal except that the header starts with
17 * 0x00 0x20.
18 *
19 * The device simply need some stuff to understand data coming from the usb
20 * buffer: The First and Second byte is used for a Header, the Third and Fourth
21 * tells the device the amount of information the package holds.
22 * Packages are 60 bytes long Header Stuff.
23 * When writing to the device the first two bytes of the header are 0x20 0x29
24 * When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
25 * situation, when too much data arrives to the device because it sends the data
26 * but with out the header. I will use a simply hack to override this situation,
27 * if there is data coming that does not contain any header, then that is data
28 * that must go directly to the tty, as there is no documentation about if there
29 * is any other control code, I will simply check for the first
30 * one.
31 *
32 * The driver registers himself with the USB-serial core and the USB Core. I had
33 * to implement a probe function against USB-serial, because other way, the
34 * driver was attaching himself to both interfaces. I have tryed with different
35 * configurations of usb_serial_driver with out exit, only the probe function
36 * could handle this correctly.
37 *
38 * I have taken some info from a Greg Kroah-Hartman article:
39 * http://www.linuxjournal.com/article/6573
40 * And from Linux Device Driver Kit CD, which is a great work, the authors taken
41 * the work to recompile lots of information an knowladge in drivers development
42 * and made it all avaible inside a cd.
43 * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
44 *
45 */
46
47#include <asm/unaligned.h>
48#include <linux/tty.h>
49#include <linux/slab.h>
50#include <linux/module.h>
51#include <linux/tty_flip.h>
52#include <linux/usb.h>
53#include <linux/usb/serial.h>
54
55static bool debug;
56
57/* Vendor and Product ID */
58#define AIRCABLE_VID 0x16CA
59#define AIRCABLE_USB_PID 0x1502
60
61/* Protocol Stuff */
62#define HCI_HEADER_LENGTH 0x4
63#define TX_HEADER_0 0x20
64#define TX_HEADER_1 0x29
65#define RX_HEADER_0 0x00
66#define RX_HEADER_1 0x20
67#define HCI_COMPLETE_FRAME 64
68
69/* rx_flags */
70#define THROTTLED 0x01
71#define ACTUALLY_THROTTLED 0x02
72
73/*
74 * Version Information
75 */
76#define DRIVER_VERSION "v2.0"
77#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>, Johan Hovold <jhovold@gmail.com>"
78#define DRIVER_DESC "AIRcable USB Driver"
79
80/* ID table that will be registered with USB core */
81static const struct usb_device_id id_table[] = {
82 { USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
83 { },
84};
85MODULE_DEVICE_TABLE(usb, id_table);
86
87static int aircable_prepare_write_buffer(struct usb_serial_port *port,
88 void *dest, size_t size)
89{
90 int count;
91 unsigned char *buf = dest;
92
93 count = kfifo_out_locked(&port->write_fifo, buf + HCI_HEADER_LENGTH,
94 size - HCI_HEADER_LENGTH, &port->lock);
95 buf[0] = TX_HEADER_0;
96 buf[1] = TX_HEADER_1;
97 put_unaligned_le16(count, &buf[2]);
98
99 return count + HCI_HEADER_LENGTH;
100}
101
102static int aircable_probe(struct usb_serial *serial,
103 const struct usb_device_id *id)
104{
105 struct usb_host_interface *iface_desc = serial->interface->
106 cur_altsetting;
107 struct usb_endpoint_descriptor *endpoint;
108 int num_bulk_out = 0;
109 int i;
110
111 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
112 endpoint = &iface_desc->endpoint[i].desc;
113 if (usb_endpoint_is_bulk_out(endpoint)) {
114 dev_dbg(&serial->dev->dev,
115 "found bulk out on endpoint %d\n", i);
116 ++num_bulk_out;
117 }
118 }
119
120 if (num_bulk_out == 0) {
121 dev_dbg(&serial->dev->dev, "Invalid interface, discarding\n");
122 return -ENODEV;
123 }
124
125 return 0;
126}
127
128static int aircable_process_packet(struct tty_struct *tty,
129 struct usb_serial_port *port, int has_headers,
130 char *packet, int len)
131{
132 if (has_headers) {
133 len -= HCI_HEADER_LENGTH;
134 packet += HCI_HEADER_LENGTH;
135 }
136 if (len <= 0) {
137 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
138 return 0;
139 }
140
141 tty_insert_flip_string(tty, packet, len);
142
143 return len;
144}
145
146static void aircable_process_read_urb(struct urb *urb)
147{
148 struct usb_serial_port *port = urb->context;
149 char *data = (char *)urb->transfer_buffer;
150 struct tty_struct *tty;
151 int has_headers;
152 int count;
153 int len;
154 int i;
155
156 tty = tty_port_tty_get(&port->port);
157 if (!tty)
158 return;
159
160 has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0);
161
162 count = 0;
163 for (i = 0; i < urb->actual_length; i += HCI_COMPLETE_FRAME) {
164 len = min_t(int, urb->actual_length - i, HCI_COMPLETE_FRAME);
165 count += aircable_process_packet(tty, port, has_headers,
166 &data[i], len);
167 }
168
169 if (count)
170 tty_flip_buffer_push(tty);
171 tty_kref_put(tty);
172}
173
174static struct usb_serial_driver aircable_device = {
175 .driver = {
176 .owner = THIS_MODULE,
177 .name = "aircable",
178 },
179 .id_table = id_table,
180 .num_ports = 1,
181 .bulk_out_size = HCI_COMPLETE_FRAME,
182 .probe = aircable_probe,
183 .process_read_urb = aircable_process_read_urb,
184 .prepare_write_buffer = aircable_prepare_write_buffer,
185 .throttle = usb_serial_generic_throttle,
186 .unthrottle = usb_serial_generic_unthrottle,
187};
188
189static struct usb_serial_driver * const serial_drivers[] = {
190 &aircable_device, NULL
191};
192
193module_usb_serial_driver(serial_drivers, id_table);
194
195MODULE_AUTHOR(DRIVER_AUTHOR);
196MODULE_DESCRIPTION(DRIVER_DESC);
197MODULE_VERSION(DRIVER_VERSION);
198MODULE_LICENSE("GPL");
199
200module_param(debug, bool, S_IRUGO | S_IWUSR);
201MODULE_PARM_DESC(debug, "Debug enabled or not");