2 * AIRcable USB Bluetooth Dongle Driver.
4 * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
5 * This program is free software; you can redistribute it and/or modify it under
6 * the terms of the GNU General Public License version 2 as published by the
7 * Free Software Foundation.
9 * The device works as an standard CDC device, it has 2 interfaces, the first
10 * one is for firmware access and the second is the serial one.
11 * The protocol is very simply, there are two posibilities reading or writing.
12 * When writing the first urb must have a Header that starts with 0x20 0x29 the
13 * next two bytes must say how much data will be sended.
14 * When reading the process is almost equal except that the header starts with
17 * The device simply need some stuff to understand data comming from the usb
18 * buffer: The First and Second byte is used for a Header, the Third and Fourth
19 * tells the device the amount of information the package holds.
20 * Packages are 60 bytes long Header Stuff.
21 * When writing to the device the first two bytes of the header are 0x20 0x29
22 * When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
23 * situation, when too much data arrives to the device because it sends the data
24 * but with out the header. I will use a simply hack to override this situation,
25 * if there is data coming that does not contain any header, then that is data
26 * that must go directly to the tty, as there is no documentation about if there
27 * is any other control code, I will simply check for the first
30 * The driver registers himself with the USB-serial core and the USB Core. I had
31 * to implement a probe function agains USB-serial, because other way, the
32 * driver was attaching himself to both interfaces. I have tryed with different
33 * configurations of usb_serial_driver with out exit, only the probe function
34 * could handle this correctly.
36 * I have taken some info from a Greg Kroah-Hartman article:
37 * http://www.linuxjournal.com/article/6573
38 * And from Linux Device Driver Kit CD, which is a great work, the authors taken
39 * the work to recompile lots of information an knowladge in drivers development
40 * and made it all avaible inside a cd.
41 * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
45 #include <linux/tty.h>
46 #include <linux/slab.h>
47 #include <linux/tty_flip.h>
48 #include <linux/circ_buf.h>
49 #include <linux/usb.h>
50 #include <linux/usb/serial.h>
54 /* Vendor and Product ID */
55 #define AIRCABLE_VID 0x16CA
56 #define AIRCABLE_USB_PID 0x1502
58 /* write buffer size defines */
59 #define AIRCABLE_BUF_SIZE 2048
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 MAX_HCI_FRAMESIZE 60
68 #define HCI_COMPLETE_FRAME 64
71 #define THROTTLED 0x01
72 #define ACTUALLY_THROTTLED 0x02
77 #define DRIVER_VERSION "v1.0b2"
78 #define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
79 #define DRIVER_DESC "AIRcable USB Driver"
81 /* ID table that will be registered with USB core */
82 static const struct usb_device_id id_table
[] = {
83 { USB_DEVICE(AIRCABLE_VID
, AIRCABLE_USB_PID
) },
86 MODULE_DEVICE_TABLE(usb
, id_table
);
89 /* Internal Structure */
90 struct aircable_private
{
91 spinlock_t rx_lock
; /* spinlock for the receive lines */
92 struct circ_buf
*tx_buf
; /* write buffer */
93 struct circ_buf
*rx_buf
; /* read buffer */
94 int rx_flags
; /* for throttilng */
95 struct work_struct rx_work
; /* work cue for the receiving line */
96 struct usb_serial_port
*port
; /* USB port with which associated */
101 /* Circular Buffer Methods, code from ti_usb_3410_5052 used */
105 * Clear out all data in the circular buffer.
107 static void serial_buf_clear(struct circ_buf
*cb
)
109 cb
->head
= cb
->tail
= 0;
115 * Allocate a circular buffer and all associated memory.
117 static struct circ_buf
*serial_buf_alloc(void)
120 cb
= kmalloc(sizeof(struct circ_buf
), GFP_KERNEL
);
123 cb
->buf
= kmalloc(AIRCABLE_BUF_SIZE
, GFP_KERNEL
);
124 if (cb
->buf
== NULL
) {
128 serial_buf_clear(cb
);
135 * Free the buffer and all associated memory.
137 static void serial_buf_free(struct circ_buf
*cb
)
144 * serial_buf_data_avail
146 * Return the number of bytes of data available in the circular
149 static int serial_buf_data_avail(struct circ_buf
*cb
)
151 return CIRC_CNT(cb
->head
, cb
->tail
, AIRCABLE_BUF_SIZE
);
157 * Copy data data from a user buffer and put it into the circular buffer.
158 * Restrict to the amount of space available.
160 * Return the number of bytes copied.
162 static int serial_buf_put(struct circ_buf
*cb
, const char *buf
, int count
)
166 c
= CIRC_SPACE_TO_END(cb
->head
, cb
->tail
, AIRCABLE_BUF_SIZE
);
171 memcpy(cb
->buf
+ cb
->head
, buf
, c
);
172 cb
->head
= (cb
->head
+ c
) & (AIRCABLE_BUF_SIZE
-1);
183 * Get data from the circular buffer and copy to the given buffer.
184 * Restrict to the amount of data available.
186 * Return the number of bytes copied.
188 static int serial_buf_get(struct circ_buf
*cb
, char *buf
, int count
)
192 c
= CIRC_CNT_TO_END(cb
->head
, cb
->tail
, AIRCABLE_BUF_SIZE
);
197 memcpy(buf
, cb
->buf
+ cb
->tail
, c
);
198 cb
->tail
= (cb
->tail
+ c
) & (AIRCABLE_BUF_SIZE
-1);
206 /* End of circula buffer methods */
208 static void aircable_send(struct usb_serial_port
*port
)
211 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
214 dbg("%s - port %d", __func__
, port
->number
);
215 if (port
->write_urb_busy
)
218 count
= min(serial_buf_data_avail(priv
->tx_buf
), MAX_HCI_FRAMESIZE
);
222 buf
= kzalloc(count
+ HCI_HEADER_LENGTH
, GFP_ATOMIC
);
224 dev_err(&port
->dev
, "%s- kzalloc(%d) failed.\n",
225 __func__
, count
+ HCI_HEADER_LENGTH
);
229 buf
[0] = TX_HEADER_0
;
230 buf
[1] = TX_HEADER_1
;
231 dbuf
= (__le16
*)&buf
[2];
232 *dbuf
= cpu_to_le16((u16
)count
);
233 serial_buf_get(priv
->tx_buf
, buf
+ HCI_HEADER_LENGTH
,
236 memcpy(port
->write_urb
->transfer_buffer
, buf
,
237 count
+ HCI_HEADER_LENGTH
);
240 port
->write_urb_busy
= 1;
241 usb_serial_debug_data(debug
, &port
->dev
, __func__
,
242 count
+ HCI_HEADER_LENGTH
,
243 port
->write_urb
->transfer_buffer
);
244 port
->write_urb
->transfer_buffer_length
= count
+ HCI_HEADER_LENGTH
;
245 port
->write_urb
->dev
= port
->serial
->dev
;
246 result
= usb_submit_urb(port
->write_urb
, GFP_ATOMIC
);
250 "%s - failed submitting write urb, error %d\n",
252 port
->write_urb_busy
= 0;
255 schedule_work(&port
->work
);
258 static void aircable_read(struct work_struct
*work
)
260 struct aircable_private
*priv
=
261 container_of(work
, struct aircable_private
, rx_work
);
262 struct usb_serial_port
*port
= priv
->port
;
263 struct tty_struct
*tty
;
266 if (priv
->rx_flags
& THROTTLED
) {
267 if (priv
->rx_flags
& ACTUALLY_THROTTLED
)
268 schedule_work(&priv
->rx_work
);
272 /* By now I will flush data to the tty in packages of no more than
273 * 64 bytes, to ensure I do not get throttled.
274 * Ask USB mailing list for better aproach.
276 tty
= tty_port_tty_get(&port
->port
);
279 schedule_work(&priv
->rx_work
);
280 dev_err(&port
->dev
, "%s - No tty available\n", __func__
);
284 count
= min(64, serial_buf_data_avail(priv
->rx_buf
));
287 goto out
; /* We have finished sending everything. */
289 tty_prepare_flip_string(tty
, &data
, count
);
291 dev_err(&port
->dev
, "%s- kzalloc(%d) failed.",
296 serial_buf_get(priv
->rx_buf
, data
, count
);
298 tty_flip_buffer_push(tty
);
300 if (serial_buf_data_avail(priv
->rx_buf
))
301 schedule_work(&priv
->rx_work
);
306 /* End of private methods */
308 static int aircable_probe(struct usb_serial
*serial
,
309 const struct usb_device_id
*id
)
311 struct usb_host_interface
*iface_desc
= serial
->interface
->
313 struct usb_endpoint_descriptor
*endpoint
;
314 int num_bulk_out
= 0;
317 for (i
= 0; i
< iface_desc
->desc
.bNumEndpoints
; i
++) {
318 endpoint
= &iface_desc
->endpoint
[i
].desc
;
319 if (usb_endpoint_is_bulk_out(endpoint
)) {
320 dbg("found bulk out on endpoint %d", i
);
325 if (num_bulk_out
== 0) {
326 dbg("Invalid interface, discarding");
333 static int aircable_attach(struct usb_serial
*serial
)
335 struct usb_serial_port
*port
= serial
->port
[0];
336 struct aircable_private
*priv
;
338 priv
= kzalloc(sizeof(struct aircable_private
), GFP_KERNEL
);
340 dev_err(&port
->dev
, "%s- kmalloc(%Zd) failed.\n", __func__
,
341 sizeof(struct aircable_private
));
345 /* Allocation of Circular Buffers */
346 priv
->tx_buf
= serial_buf_alloc();
347 if (priv
->tx_buf
== NULL
) {
352 priv
->rx_buf
= serial_buf_alloc();
353 if (priv
->rx_buf
== NULL
) {
359 priv
->rx_flags
&= ~(THROTTLED
| ACTUALLY_THROTTLED
);
361 INIT_WORK(&priv
->rx_work
, aircable_read
);
363 usb_set_serial_port_data(serial
->port
[0], priv
);
368 static void aircable_release(struct usb_serial
*serial
)
371 struct usb_serial_port
*port
= serial
->port
[0];
372 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
377 serial_buf_free(priv
->tx_buf
);
378 serial_buf_free(priv
->rx_buf
);
383 static int aircable_write_room(struct tty_struct
*tty
)
385 struct usb_serial_port
*port
= tty
->driver_data
;
386 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
387 return serial_buf_data_avail(priv
->tx_buf
);
390 static int aircable_write(struct tty_struct
*tty
, struct usb_serial_port
*port
,
391 const unsigned char *source
, int count
)
393 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
396 dbg("%s - port %d, %d bytes", __func__
, port
->number
, count
);
398 usb_serial_debug_data(debug
, &port
->dev
, __func__
, count
, source
);
401 dbg("%s - write request of 0 bytes", __func__
);
405 temp
= serial_buf_put(priv
->tx_buf
, source
, count
);
409 if (count
> AIRCABLE_BUF_SIZE
)
410 count
= AIRCABLE_BUF_SIZE
;
416 static void aircable_write_bulk_callback(struct urb
*urb
)
418 struct usb_serial_port
*port
= urb
->context
;
419 int status
= urb
->status
;
422 dbg("%s - urb status: %d", __func__
, status
);
424 /* This has been taken from cypress_m8.c cypress_write_int_callback */
432 /* this urb is terminated, clean up */
433 dbg("%s - urb shutting down with status: %d",
435 port
->write_urb_busy
= 0;
438 /* error in the urb, so we have to resubmit it */
439 dbg("%s - Overflow in write", __func__
);
440 dbg("%s - nonzero write bulk status received: %d",
442 port
->write_urb
->transfer_buffer_length
= 1;
443 port
->write_urb
->dev
= port
->serial
->dev
;
444 result
= usb_submit_urb(port
->write_urb
, GFP_ATOMIC
);
446 dev_err(&urb
->dev
->dev
,
447 "%s - failed resubmitting write urb, error %d\n",
453 port
->write_urb_busy
= 0;
458 static void aircable_read_bulk_callback(struct urb
*urb
)
460 struct usb_serial_port
*port
= urb
->context
;
461 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
462 struct tty_struct
*tty
;
463 unsigned long no_packages
, remaining
, package_length
, i
;
464 int result
, shift
= 0;
466 int status
= urb
->status
;
468 dbg("%s - port %d", __func__
, port
->number
);
471 dbg("%s - urb status = %d", __func__
, status
);
472 if (status
== -EPROTO
) {
473 dbg("%s - caught -EPROTO, resubmitting the urb",
475 usb_fill_bulk_urb(port
->read_urb
, port
->serial
->dev
,
476 usb_rcvbulkpipe(port
->serial
->dev
,
477 port
->bulk_in_endpointAddress
),
478 port
->read_urb
->transfer_buffer
,
479 port
->read_urb
->transfer_buffer_length
,
480 aircable_read_bulk_callback
, port
);
482 result
= usb_submit_urb(urb
, GFP_ATOMIC
);
484 dev_err(&urb
->dev
->dev
,
485 "%s - failed resubmitting read urb, error %d\n",
489 dbg("%s - unable to handle the error, exiting.", __func__
);
493 usb_serial_debug_data(debug
, &port
->dev
, __func__
,
494 urb
->actual_length
, urb
->transfer_buffer
);
496 tty
= tty_port_tty_get(&port
->port
);
497 if (tty
&& urb
->actual_length
) {
498 if (urb
->actual_length
<= 2) {
499 /* This is an incomplete package */
500 serial_buf_put(priv
->rx_buf
, urb
->transfer_buffer
,
503 temp
= urb
->transfer_buffer
;
504 if (temp
[0] == RX_HEADER_0
)
505 shift
= HCI_HEADER_LENGTH
;
507 remaining
= urb
->actual_length
;
508 no_packages
= urb
->actual_length
/ (HCI_COMPLETE_FRAME
);
510 if (urb
->actual_length
% HCI_COMPLETE_FRAME
!= 0)
513 for (i
= 0; i
< no_packages
; i
++) {
514 if (remaining
> (HCI_COMPLETE_FRAME
))
515 package_length
= HCI_COMPLETE_FRAME
;
517 package_length
= remaining
;
518 remaining
-= package_length
;
520 serial_buf_put(priv
->rx_buf
,
521 urb
->transfer_buffer
+ shift
+
522 (HCI_COMPLETE_FRAME
) * (i
),
523 package_length
- shift
);
526 aircable_read(&priv
->rx_work
);
530 /* Schedule the next read */
531 usb_fill_bulk_urb(port
->read_urb
, port
->serial
->dev
,
532 usb_rcvbulkpipe(port
->serial
->dev
,
533 port
->bulk_in_endpointAddress
),
534 port
->read_urb
->transfer_buffer
,
535 port
->read_urb
->transfer_buffer_length
,
536 aircable_read_bulk_callback
, port
);
538 result
= usb_submit_urb(urb
, GFP_ATOMIC
);
539 if (result
&& result
!= -EPERM
)
540 dev_err(&urb
->dev
->dev
,
541 "%s - failed resubmitting read urb, error %d\n",
545 /* Based on ftdi_sio.c throttle */
546 static void aircable_throttle(struct tty_struct
*tty
)
548 struct usb_serial_port
*port
= tty
->driver_data
;
549 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
551 dbg("%s - port %d", __func__
, port
->number
);
553 spin_lock_irq(&priv
->rx_lock
);
554 priv
->rx_flags
|= THROTTLED
;
555 spin_unlock_irq(&priv
->rx_lock
);
558 /* Based on ftdi_sio.c unthrottle */
559 static void aircable_unthrottle(struct tty_struct
*tty
)
561 struct usb_serial_port
*port
= tty
->driver_data
;
562 struct aircable_private
*priv
= usb_get_serial_port_data(port
);
563 int actually_throttled
;
565 dbg("%s - port %d", __func__
, port
->number
);
567 spin_lock_irq(&priv
->rx_lock
);
568 actually_throttled
= priv
->rx_flags
& ACTUALLY_THROTTLED
;
569 priv
->rx_flags
&= ~(THROTTLED
| ACTUALLY_THROTTLED
);
570 spin_unlock_irq(&priv
->rx_lock
);
572 if (actually_throttled
)
573 schedule_work(&priv
->rx_work
);
576 static struct usb_driver aircable_driver
= {
578 .probe
= usb_serial_probe
,
579 .disconnect
= usb_serial_disconnect
,
580 .id_table
= id_table
,
584 static struct usb_serial_driver aircable_device
= {
586 .owner
= THIS_MODULE
,
589 .usb_driver
= &aircable_driver
,
590 .id_table
= id_table
,
592 .attach
= aircable_attach
,
593 .probe
= aircable_probe
,
594 .release
= aircable_release
,
595 .write
= aircable_write
,
596 .write_room
= aircable_write_room
,
597 .write_bulk_callback
= aircable_write_bulk_callback
,
598 .read_bulk_callback
= aircable_read_bulk_callback
,
599 .throttle
= aircable_throttle
,
600 .unthrottle
= aircable_unthrottle
,
603 static int __init
aircable_init(void)
606 retval
= usb_serial_register(&aircable_device
);
608 goto failed_serial_register
;
609 retval
= usb_register(&aircable_driver
);
611 goto failed_usb_register
;
615 usb_serial_deregister(&aircable_device
);
616 failed_serial_register
:
620 static void __exit
aircable_exit(void)
622 usb_deregister(&aircable_driver
);
623 usb_serial_deregister(&aircable_device
);
626 MODULE_AUTHOR(DRIVER_AUTHOR
);
627 MODULE_DESCRIPTION(DRIVER_DESC
);
628 MODULE_VERSION(DRIVER_VERSION
);
629 MODULE_LICENSE("GPL");
631 module_init(aircable_init
);
632 module_exit(aircable_exit
);
634 module_param(debug
, bool, S_IRUGO
| S_IWUSR
);
635 MODULE_PARM_DESC(debug
, "Debug enabled or not");