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");