Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6] / drivers / usb / serial / aircable.c
1 /*
2  * AIRcable USB Bluetooth Dongle Driver.
3  *
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.
8  *
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
15  * 0x00 0x20.
16  *
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
28  * one.
29  *
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.
35  *
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/
42  *
43  */
44
45 #include <linux/tty.h>
46 #include <linux/tty_flip.h>
47 #include <linux/circ_buf.h>
48 #include <linux/usb.h>
49 #include <linux/usb/serial.h>
50
51 static int debug;
52
53 /* Vendor and Product ID */
54 #define AIRCABLE_VID            0x16CA
55 #define AIRCABLE_USB_PID        0x1502
56
57 /* write buffer size defines */
58 #define AIRCABLE_BUF_SIZE       2048
59
60 /* Protocol Stuff */
61 #define HCI_HEADER_LENGTH       0x4
62 #define TX_HEADER_0             0x20
63 #define TX_HEADER_1             0x29
64 #define RX_HEADER_0             0x00
65 #define RX_HEADER_1             0x20
66 #define MAX_HCI_FRAMESIZE       60
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 "v1.0b2"
77 #define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
78 #define DRIVER_DESC "AIRcable USB Driver"
79
80 /* ID table that will be registered with USB core */
81 static struct usb_device_id id_table [] = {
82         { USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
83         { },
84 };
85 MODULE_DEVICE_TABLE(usb, id_table);
86
87
88 /* Internal Structure */
89 struct aircable_private {
90         spinlock_t rx_lock;             /* spinlock for the receive lines */
91         struct circ_buf *tx_buf;        /* write buffer */
92         struct circ_buf *rx_buf;        /* read buffer */
93         int rx_flags;                   /* for throttilng */
94         struct work_struct rx_work;     /* work cue for the receiving line */
95         struct usb_serial_port *port;   /* USB port with which associated */
96 };
97
98 /* Private methods */
99
100 /* Circular Buffer Methods, code from ti_usb_3410_5052 used */
101 /*
102  * serial_buf_clear
103  *
104  * Clear out all data in the circular buffer.
105  */
106 static void serial_buf_clear(struct circ_buf *cb)
107 {
108         cb->head = cb->tail = 0;
109 }
110
111 /*
112  * serial_buf_alloc
113  *
114  * Allocate a circular buffer and all associated memory.
115  */
116 static struct circ_buf *serial_buf_alloc(void)
117 {
118         struct circ_buf *cb;
119         cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
120         if (cb == NULL)
121                 return NULL;
122         cb->buf = kmalloc(AIRCABLE_BUF_SIZE, GFP_KERNEL);
123         if (cb->buf == NULL) {
124                 kfree(cb);
125                 return NULL;
126         }
127         serial_buf_clear(cb);
128         return cb;
129 }
130
131 /*
132  * serial_buf_free
133  *
134  * Free the buffer and all associated memory.
135  */
136 static void serial_buf_free(struct circ_buf *cb)
137 {
138         kfree(cb->buf);
139         kfree(cb);
140 }
141
142 /*
143  * serial_buf_data_avail
144  *
145  * Return the number of bytes of data available in the circular
146  * buffer.
147  */
148 static int serial_buf_data_avail(struct circ_buf *cb)
149 {
150         return CIRC_CNT(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
151 }
152
153 /*
154  * serial_buf_put
155  *
156  * Copy data data from a user buffer and put it into the circular buffer.
157  * Restrict to the amount of space available.
158  *
159  * Return the number of bytes copied.
160  */
161 static int serial_buf_put(struct circ_buf *cb, const char *buf, int count)
162 {
163         int c, ret = 0;
164         while (1) {
165                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
166                 if (count < c)
167                         c = count;
168                 if (c <= 0)
169                         break;
170                 memcpy(cb->buf + cb->head, buf, c);
171                 cb->head = (cb->head + c) & (AIRCABLE_BUF_SIZE-1);
172                 buf += c;
173                 count -= c;
174                 ret = c;
175         }
176         return ret;
177 }
178
179 /*
180  * serial_buf_get
181  *
182  * Get data from the circular buffer and copy to the given buffer.
183  * Restrict to the amount of data available.
184  *
185  * Return the number of bytes copied.
186  */
187 static int serial_buf_get(struct circ_buf *cb, char *buf, int count)
188 {
189         int c, ret = 0;
190         while (1) {
191                 c = CIRC_CNT_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
192                 if (count < c)
193                         c = count;
194                 if (c <= 0)
195                         break;
196                 memcpy(buf, cb->buf + cb->tail, c);
197                 cb->tail = (cb->tail + c) & (AIRCABLE_BUF_SIZE-1);
198                 buf += c;
199                 count -= c;
200                 ret = c;
201         }
202         return ret;
203 }
204
205 /* End of circula buffer methods */
206
207 static void aircable_send(struct usb_serial_port *port)
208 {
209         int count, result;
210         struct aircable_private *priv = usb_get_serial_port_data(port);
211         unsigned char *buf;
212         __le16 *dbuf;
213         dbg("%s - port %d", __func__, port->number);
214         if (port->write_urb_busy)
215                 return;
216
217         count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
218         if (count == 0)
219                 return;
220
221         buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
222         if (!buf) {
223                 err("%s- kzalloc(%d) failed.", __func__,
224                     count + HCI_HEADER_LENGTH);
225                 return;
226         }
227
228         buf[0] = TX_HEADER_0;
229         buf[1] = TX_HEADER_1;
230         dbuf = (__le16 *)&buf[2];
231         *dbuf = cpu_to_le16((u16)count);
232         serial_buf_get(priv->tx_buf, buf + HCI_HEADER_LENGTH,
233                                                         MAX_HCI_FRAMESIZE);
234
235         memcpy(port->write_urb->transfer_buffer, buf,
236                count + HCI_HEADER_LENGTH);
237
238         kfree(buf);
239         port->write_urb_busy = 1;
240         usb_serial_debug_data(debug, &port->dev, __func__,
241                               count + HCI_HEADER_LENGTH,
242                               port->write_urb->transfer_buffer);
243         port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
244         port->write_urb->dev = port->serial->dev;
245         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
246
247         if (result) {
248                 dev_err(&port->dev,
249                         "%s - failed submitting write urb, error %d\n",
250                         __func__, result);
251                 port->write_urb_busy = 0;
252         }
253
254         schedule_work(&port->work);
255 }
256
257 static void aircable_read(struct work_struct *work)
258 {
259         struct aircable_private *priv =
260                 container_of(work, struct aircable_private, rx_work);
261         struct usb_serial_port *port = priv->port;
262         struct tty_struct *tty;
263         unsigned char *data;
264         int count;
265         if (priv->rx_flags & THROTTLED) {
266                 if (priv->rx_flags & ACTUALLY_THROTTLED)
267                         schedule_work(&priv->rx_work);
268                 return;
269         }
270
271         /* By now I will flush data to the tty in packages of no more than
272          * 64 bytes, to ensure I do not get throttled.
273          * Ask USB mailing list for better aproach.
274          */
275         tty = tty_port_tty_get(&port->port);
276
277         if (!tty) {
278                 schedule_work(&priv->rx_work);
279                 err("%s - No tty available", __func__);
280                 return ;
281         }
282
283         count = min(64, serial_buf_data_avail(priv->rx_buf));
284
285         if (count <= 0)
286                 goto out; /* We have finished sending everything. */
287
288         tty_prepare_flip_string(tty, &data, count);
289         if (!data) {
290                 dev_err(&port->dev, "%s- kzalloc(%d) failed.",
291                                                         __func__, count);
292                 goto out;
293         }
294
295         serial_buf_get(priv->rx_buf, data, count);
296
297         tty_flip_buffer_push(tty);
298
299         if (serial_buf_data_avail(priv->rx_buf))
300                 schedule_work(&priv->rx_work);
301 out:            
302         tty_kref_put(tty);
303         return;
304 }
305 /* End of private methods */
306
307 static int aircable_probe(struct usb_serial *serial,
308                           const struct usb_device_id *id)
309 {
310         struct usb_host_interface *iface_desc = serial->interface->
311                                                                 cur_altsetting;
312         struct usb_endpoint_descriptor *endpoint;
313         int num_bulk_out = 0;
314         int i;
315
316         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
317                 endpoint = &iface_desc->endpoint[i].desc;
318                 if (usb_endpoint_is_bulk_out(endpoint)) {
319                         dbg("found bulk out on endpoint %d", i);
320                         ++num_bulk_out;
321                 }
322         }
323
324         if (num_bulk_out == 0) {
325                 dbg("Invalid interface, discarding");
326                 return -ENODEV;
327         }
328
329         return 0;
330 }
331
332 static int aircable_attach(struct usb_serial *serial)
333 {
334         struct usb_serial_port *port = serial->port[0];
335         struct aircable_private *priv;
336
337         priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
338         if (!priv) {
339                 err("%s- kmalloc(%Zd) failed.", __func__,
340                         sizeof(struct aircable_private));
341                 return -ENOMEM;
342         }
343
344         /* Allocation of Circular Buffers */
345         priv->tx_buf = serial_buf_alloc();
346         if (priv->tx_buf == NULL) {
347                 kfree(priv);
348                 return -ENOMEM;
349         }
350
351         priv->rx_buf = serial_buf_alloc();
352         if (priv->rx_buf == NULL) {
353                 kfree(priv->tx_buf);
354                 kfree(priv);
355                 return -ENOMEM;
356         }
357
358         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
359         priv->port = port;
360         INIT_WORK(&priv->rx_work, aircable_read);
361
362         usb_set_serial_port_data(serial->port[0], priv);
363
364         return 0;
365 }
366
367 static void aircable_shutdown(struct usb_serial *serial)
368 {
369
370         struct usb_serial_port *port = serial->port[0];
371         struct aircable_private *priv = usb_get_serial_port_data(port);
372
373         dbg("%s", __func__);
374
375         if (priv) {
376                 serial_buf_free(priv->tx_buf);
377                 serial_buf_free(priv->rx_buf);
378                 usb_set_serial_port_data(port, NULL);
379                 kfree(priv);
380         }
381 }
382
383 static int aircable_write_room(struct tty_struct *tty)
384 {
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);
388 }
389
390 static int aircable_write(struct tty_struct *tty, struct usb_serial_port *port,
391                           const unsigned char *source, int count)
392 {
393         struct aircable_private *priv = usb_get_serial_port_data(port);
394         int temp;
395
396         dbg("%s - port %d, %d bytes", __func__, port->number, count);
397
398         usb_serial_debug_data(debug, &port->dev, __func__, count, source);
399
400         if (!count) {
401                 dbg("%s - write request of 0 bytes", __func__);
402                 return count;
403         }
404
405         temp = serial_buf_put(priv->tx_buf, source, count);
406
407         aircable_send(port);
408
409         if (count > AIRCABLE_BUF_SIZE)
410                 count = AIRCABLE_BUF_SIZE;
411
412         return count;
413
414 }
415
416 static void aircable_write_bulk_callback(struct urb *urb)
417 {
418         struct usb_serial_port *port = urb->context;
419         int status = urb->status;
420         int result;
421
422         dbg("%s - urb status: %d", __func__ , status);
423
424         /* This has been taken from cypress_m8.c cypress_write_int_callback */
425         switch (status) {
426         case 0:
427                 /* success */
428                 break;
429         case -ECONNRESET:
430         case -ENOENT:
431         case -ESHUTDOWN:
432                 /* this urb is terminated, clean up */
433                 dbg("%s - urb shutting down with status: %d",
434                     __func__, status);
435                 port->write_urb_busy = 0;
436                 return;
437         default:
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",
441                     __func__, status);
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);
445                 if (result)
446                         dev_err(&urb->dev->dev,
447                             "%s - failed resubmitting write urb, error %d\n",
448                                                         __func__, result);
449                 else
450                         return;
451         }
452
453         port->write_urb_busy = 0;
454
455         aircable_send(port);
456 }
457
458 static void aircable_read_bulk_callback(struct urb *urb)
459 {
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;
465         unsigned char *temp;
466         int status = urb->status;
467
468         dbg("%s - port %d", __func__, port->number);
469
470         if (status) {
471                 dbg("%s - urb status = %d", __func__, status);
472                 if (!port->port.count) {
473                         dbg("%s - port is closed, exiting.", __func__);
474                         return;
475                 }
476                 if (status == -EPROTO) {
477                         dbg("%s - caught -EPROTO, resubmitting the urb",
478                             __func__);
479                         usb_fill_bulk_urb(port->read_urb, port->serial->dev,
480                                 usb_rcvbulkpipe(port->serial->dev,
481                                         port->bulk_in_endpointAddress),
482                                 port->read_urb->transfer_buffer,
483                                 port->read_urb->transfer_buffer_length,
484                                 aircable_read_bulk_callback, port);
485
486                         result = usb_submit_urb(urb, GFP_ATOMIC);
487                         if (result)
488                                 dev_err(&urb->dev->dev,
489                                         "%s - failed resubmitting read urb, error %d\n",
490                                         __func__, result);
491                         return;
492                 }
493                 dbg("%s - unable to handle the error, exiting.", __func__);
494                 return;
495         }
496
497         usb_serial_debug_data(debug, &port->dev, __func__,
498                                 urb->actual_length, urb->transfer_buffer);
499
500         tty = tty_port_tty_get(&port->port);
501         if (tty && urb->actual_length) {
502                 if (urb->actual_length <= 2) {
503                         /* This is an incomplete package */
504                         serial_buf_put(priv->rx_buf, urb->transfer_buffer,
505                                        urb->actual_length);
506                 } else {
507                         temp = urb->transfer_buffer;
508                         if (temp[0] == RX_HEADER_0)
509                                 shift = HCI_HEADER_LENGTH;
510
511                         remaining = urb->actual_length;
512                         no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
513
514                         if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
515                                 no_packages++;
516
517                         for (i = 0; i < no_packages; i++) {
518                                 if (remaining > (HCI_COMPLETE_FRAME))
519                                         package_length = HCI_COMPLETE_FRAME;
520                                 else
521                                         package_length = remaining;
522                                 remaining -= package_length;
523
524                                 serial_buf_put(priv->rx_buf,
525                                         urb->transfer_buffer + shift +
526                                         (HCI_COMPLETE_FRAME) * (i),
527                                         package_length - shift);
528                         }
529                 }
530                 aircable_read(&priv->rx_work);
531         }
532         tty_kref_put(tty);
533
534         /* Schedule the next read _if_ we are still open */
535         if (port->port.count) {
536                 usb_fill_bulk_urb(port->read_urb, port->serial->dev,
537                                   usb_rcvbulkpipe(port->serial->dev,
538                                           port->bulk_in_endpointAddress),
539                                   port->read_urb->transfer_buffer,
540                                   port->read_urb->transfer_buffer_length,
541                                   aircable_read_bulk_callback, port);
542
543                 result = usb_submit_urb(urb, GFP_ATOMIC);
544                 if (result)
545                         dev_err(&urb->dev->dev,
546                                 "%s - failed resubmitting read urb, error %d\n",
547                                 __func__, result);
548         }
549
550         return;
551 }
552
553 /* Based on ftdi_sio.c throttle */
554 static void aircable_throttle(struct tty_struct *tty)
555 {
556         struct usb_serial_port *port = tty->driver_data;
557         struct aircable_private *priv = usb_get_serial_port_data(port);
558         unsigned long flags;
559
560         dbg("%s - port %d", __func__, port->number);
561
562         spin_lock_irqsave(&priv->rx_lock, flags);
563         priv->rx_flags |= THROTTLED;
564         spin_unlock_irqrestore(&priv->rx_lock, flags);
565 }
566
567 /* Based on ftdi_sio.c unthrottle */
568 static void aircable_unthrottle(struct tty_struct *tty)
569 {
570         struct usb_serial_port *port = tty->driver_data;
571         struct aircable_private *priv = usb_get_serial_port_data(port);
572         int actually_throttled;
573         unsigned long flags;
574
575         dbg("%s - port %d", __func__, port->number);
576
577         spin_lock_irqsave(&priv->rx_lock, flags);
578         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
579         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
580         spin_unlock_irqrestore(&priv->rx_lock, flags);
581
582         if (actually_throttled)
583                 schedule_work(&priv->rx_work);
584 }
585
586 static struct usb_driver aircable_driver = {
587         .name =         "aircable",
588         .probe =        usb_serial_probe,
589         .disconnect =   usb_serial_disconnect,
590         .id_table =     id_table,
591         .no_dynamic_id =        1,
592 };
593
594 static struct usb_serial_driver aircable_device = {
595         .driver = {
596                 .owner =        THIS_MODULE,
597                 .name =         "aircable",
598         },
599         .usb_driver =           &aircable_driver,
600         .id_table =             id_table,
601         .num_ports =            1,
602         .attach =               aircable_attach,
603         .probe =                aircable_probe,
604         .shutdown =             aircable_shutdown,
605         .write =                aircable_write,
606         .write_room =           aircable_write_room,
607         .write_bulk_callback =  aircable_write_bulk_callback,
608         .read_bulk_callback =   aircable_read_bulk_callback,
609         .throttle =             aircable_throttle,
610         .unthrottle =           aircable_unthrottle,
611 };
612
613 static int __init aircable_init(void)
614 {
615         int retval;
616         retval = usb_serial_register(&aircable_device);
617         if (retval)
618                 goto failed_serial_register;
619         retval = usb_register(&aircable_driver);
620         if (retval)
621                 goto failed_usb_register;
622         return 0;
623
624 failed_serial_register:
625         usb_serial_deregister(&aircable_device);
626 failed_usb_register:
627         return retval;
628 }
629
630 static void __exit aircable_exit(void)
631 {
632         usb_deregister(&aircable_driver);
633         usb_serial_deregister(&aircable_device);
634 }
635
636 MODULE_AUTHOR(DRIVER_AUTHOR);
637 MODULE_DESCRIPTION(DRIVER_DESC);
638 MODULE_VERSION(DRIVER_VERSION);
639 MODULE_LICENSE("GPL");
640
641 module_init(aircable_init);
642 module_exit(aircable_exit);
643
644 module_param(debug, bool, S_IRUGO | S_IWUSR);
645 MODULE_PARM_DESC(debug, "Debug enabled or not");