Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
[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 = port->port.tty;
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                 return; /* We have finished sending everything. */
287
288         tty_prepare_flip_string(tty, &data, count);
289         if (!data) {
290                 err("%s- kzalloc(%d) failed.", __func__, count);
291                 return;
292         }
293
294         serial_buf_get(priv->rx_buf, data, count);
295
296         tty_flip_buffer_push(tty);
297
298         if (serial_buf_data_avail(priv->rx_buf))
299                 schedule_work(&priv->rx_work);
300
301         return;
302 }
303 /* End of private methods */
304
305 static int aircable_probe(struct usb_serial *serial,
306                           const struct usb_device_id *id)
307 {
308         struct usb_host_interface *iface_desc = serial->interface->
309                                                                 cur_altsetting;
310         struct usb_endpoint_descriptor *endpoint;
311         int num_bulk_out = 0;
312         int i;
313
314         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
315                 endpoint = &iface_desc->endpoint[i].desc;
316                 if (usb_endpoint_is_bulk_out(endpoint)) {
317                         dbg("found bulk out on endpoint %d", i);
318                         ++num_bulk_out;
319                 }
320         }
321
322         if (num_bulk_out == 0) {
323                 dbg("Invalid interface, discarding");
324                 return -ENODEV;
325         }
326
327         return 0;
328 }
329
330 static int aircable_attach(struct usb_serial *serial)
331 {
332         struct usb_serial_port *port = serial->port[0];
333         struct aircable_private *priv;
334
335         priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
336         if (!priv) {
337                 err("%s- kmalloc(%Zd) failed.", __func__,
338                         sizeof(struct aircable_private));
339                 return -ENOMEM;
340         }
341
342         /* Allocation of Circular Buffers */
343         priv->tx_buf = serial_buf_alloc();
344         if (priv->tx_buf == NULL) {
345                 kfree(priv);
346                 return -ENOMEM;
347         }
348
349         priv->rx_buf = serial_buf_alloc();
350         if (priv->rx_buf == NULL) {
351                 kfree(priv->tx_buf);
352                 kfree(priv);
353                 return -ENOMEM;
354         }
355
356         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
357         priv->port = port;
358         INIT_WORK(&priv->rx_work, aircable_read);
359
360         usb_set_serial_port_data(serial->port[0], priv);
361
362         return 0;
363 }
364
365 static void aircable_shutdown(struct usb_serial *serial)
366 {
367
368         struct usb_serial_port *port = serial->port[0];
369         struct aircable_private *priv = usb_get_serial_port_data(port);
370
371         dbg("%s", __func__);
372
373         if (priv) {
374                 serial_buf_free(priv->tx_buf);
375                 serial_buf_free(priv->rx_buf);
376                 usb_set_serial_port_data(port, NULL);
377                 kfree(priv);
378         }
379 }
380
381 static int aircable_write_room(struct tty_struct *tty)
382 {
383         struct usb_serial_port *port = tty->driver_data;
384         struct aircable_private *priv = usb_get_serial_port_data(port);
385         return serial_buf_data_avail(priv->tx_buf);
386 }
387
388 static int aircable_write(struct tty_struct *tty, struct usb_serial_port *port,
389                           const unsigned char *source, int count)
390 {
391         struct aircable_private *priv = usb_get_serial_port_data(port);
392         int temp;
393
394         dbg("%s - port %d, %d bytes", __func__, port->number, count);
395
396         usb_serial_debug_data(debug, &port->dev, __func__, count, source);
397
398         if (!count) {
399                 dbg("%s - write request of 0 bytes", __func__);
400                 return count;
401         }
402
403         temp = serial_buf_put(priv->tx_buf, source, count);
404
405         aircable_send(port);
406
407         if (count > AIRCABLE_BUF_SIZE)
408                 count = AIRCABLE_BUF_SIZE;
409
410         return count;
411
412 }
413
414 static void aircable_write_bulk_callback(struct urb *urb)
415 {
416         struct usb_serial_port *port = urb->context;
417         int status = urb->status;
418         int result;
419
420         dbg("%s - urb status: %d", __func__ , status);
421
422         /* This has been taken from cypress_m8.c cypress_write_int_callback */
423         switch (status) {
424         case 0:
425                 /* success */
426                 break;
427         case -ECONNRESET:
428         case -ENOENT:
429         case -ESHUTDOWN:
430                 /* this urb is terminated, clean up */
431                 dbg("%s - urb shutting down with status: %d",
432                     __func__, status);
433                 port->write_urb_busy = 0;
434                 return;
435         default:
436                 /* error in the urb, so we have to resubmit it */
437                 dbg("%s - Overflow in write", __func__);
438                 dbg("%s - nonzero write bulk status received: %d",
439                     __func__, status);
440                 port->write_urb->transfer_buffer_length = 1;
441                 port->write_urb->dev = port->serial->dev;
442                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
443                 if (result)
444                         dev_err(&urb->dev->dev,
445                             "%s - failed resubmitting write urb, error %d\n",
446                                                         __func__, result);
447                 else
448                         return;
449         }
450
451         port->write_urb_busy = 0;
452
453         aircable_send(port);
454 }
455
456 static void aircable_read_bulk_callback(struct urb *urb)
457 {
458         struct usb_serial_port *port = urb->context;
459         struct aircable_private *priv = usb_get_serial_port_data(port);
460         struct tty_struct *tty;
461         unsigned long no_packages, remaining, package_length, i;
462         int result, shift = 0;
463         unsigned char *temp;
464         int status = urb->status;
465
466         dbg("%s - port %d", __func__, port->number);
467
468         if (status) {
469                 dbg("%s - urb status = %d", __func__, status);
470                 if (!port->port.count) {
471                         dbg("%s - port is closed, exiting.", __func__);
472                         return;
473                 }
474                 if (status == -EPROTO) {
475                         dbg("%s - caught -EPROTO, resubmitting the urb",
476                             __func__);
477                         usb_fill_bulk_urb(port->read_urb, port->serial->dev,
478                                 usb_rcvbulkpipe(port->serial->dev,
479                                         port->bulk_in_endpointAddress),
480                                 port->read_urb->transfer_buffer,
481                                 port->read_urb->transfer_buffer_length,
482                                 aircable_read_bulk_callback, port);
483
484                         result = usb_submit_urb(urb, GFP_ATOMIC);
485                         if (result)
486                                 dev_err(&urb->dev->dev,
487                                         "%s - failed resubmitting read urb, error %d\n",
488                                         __func__, result);
489                         return;
490                 }
491                 dbg("%s - unable to handle the error, exiting.", __func__);
492                 return;
493         }
494
495         usb_serial_debug_data(debug, &port->dev, __func__,
496                                 urb->actual_length, urb->transfer_buffer);
497
498         tty = port->port.tty;
499         if (tty && urb->actual_length) {
500                 if (urb->actual_length <= 2) {
501                         /* This is an incomplete package */
502                         serial_buf_put(priv->rx_buf, urb->transfer_buffer,
503                                        urb->actual_length);
504                 } else {
505                         temp = urb->transfer_buffer;
506                         if (temp[0] == RX_HEADER_0)
507                                 shift = HCI_HEADER_LENGTH;
508
509                         remaining = urb->actual_length;
510                         no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
511
512                         if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
513                                 no_packages++;
514
515                         for (i = 0; i < no_packages; i++) {
516                                 if (remaining > (HCI_COMPLETE_FRAME))
517                                         package_length = HCI_COMPLETE_FRAME;
518                                 else
519                                         package_length = remaining;
520                                 remaining -= package_length;
521
522                                 serial_buf_put(priv->rx_buf,
523                                         urb->transfer_buffer + shift +
524                                         (HCI_COMPLETE_FRAME) * (i),
525                                         package_length - shift);
526                         }
527                 }
528                 aircable_read(&priv->rx_work);
529         }
530
531         /* Schedule the next read _if_ we are still open */
532         if (port->port.count) {
533                 usb_fill_bulk_urb(port->read_urb, port->serial->dev,
534                                   usb_rcvbulkpipe(port->serial->dev,
535                                           port->bulk_in_endpointAddress),
536                                   port->read_urb->transfer_buffer,
537                                   port->read_urb->transfer_buffer_length,
538                                   aircable_read_bulk_callback, port);
539
540                 result = usb_submit_urb(urb, GFP_ATOMIC);
541                 if (result)
542                         dev_err(&urb->dev->dev,
543                                 "%s - failed resubmitting read urb, error %d\n",
544                                 __func__, result);
545         }
546
547         return;
548 }
549
550 /* Based on ftdi_sio.c throttle */
551 static void aircable_throttle(struct tty_struct *tty)
552 {
553         struct usb_serial_port *port = tty->driver_data;
554         struct aircable_private *priv = usb_get_serial_port_data(port);
555         unsigned long flags;
556
557         dbg("%s - port %d", __func__, port->number);
558
559         spin_lock_irqsave(&priv->rx_lock, flags);
560         priv->rx_flags |= THROTTLED;
561         spin_unlock_irqrestore(&priv->rx_lock, flags);
562 }
563
564 /* Based on ftdi_sio.c unthrottle */
565 static void aircable_unthrottle(struct tty_struct *tty)
566 {
567         struct usb_serial_port *port = tty->driver_data;
568         struct aircable_private *priv = usb_get_serial_port_data(port);
569         int actually_throttled;
570         unsigned long flags;
571
572         dbg("%s - port %d", __func__, port->number);
573
574         spin_lock_irqsave(&priv->rx_lock, flags);
575         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
576         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
577         spin_unlock_irqrestore(&priv->rx_lock, flags);
578
579         if (actually_throttled)
580                 schedule_work(&priv->rx_work);
581 }
582
583 static struct usb_driver aircable_driver = {
584         .name =         "aircable",
585         .probe =        usb_serial_probe,
586         .disconnect =   usb_serial_disconnect,
587         .id_table =     id_table,
588         .no_dynamic_id =        1,
589 };
590
591 static struct usb_serial_driver aircable_device = {
592         .driver = {
593                 .owner =        THIS_MODULE,
594                 .name =         "aircable",
595         },
596         .usb_driver =           &aircable_driver,
597         .id_table =             id_table,
598         .num_ports =            1,
599         .attach =               aircable_attach,
600         .probe =                aircable_probe,
601         .shutdown =             aircable_shutdown,
602         .write =                aircable_write,
603         .write_room =           aircable_write_room,
604         .write_bulk_callback =  aircable_write_bulk_callback,
605         .read_bulk_callback =   aircable_read_bulk_callback,
606         .throttle =             aircable_throttle,
607         .unthrottle =           aircable_unthrottle,
608 };
609
610 static int __init aircable_init(void)
611 {
612         int retval;
613         retval = usb_serial_register(&aircable_device);
614         if (retval)
615                 goto failed_serial_register;
616         retval = usb_register(&aircable_driver);
617         if (retval)
618                 goto failed_usb_register;
619         return 0;
620
621 failed_serial_register:
622         usb_serial_deregister(&aircable_device);
623 failed_usb_register:
624         return retval;
625 }
626
627 static void __exit aircable_exit(void)
628 {
629         usb_deregister(&aircable_driver);
630         usb_serial_deregister(&aircable_device);
631 }
632
633 MODULE_AUTHOR(DRIVER_AUTHOR);
634 MODULE_DESCRIPTION(DRIVER_DESC);
635 MODULE_VERSION(DRIVER_VERSION);
636 MODULE_LICENSE("GPL");
637
638 module_init(aircable_init);
639 module_exit(aircable_exit);
640
641 module_param(debug, bool, S_IRUGO | S_IWUSR);
642 MODULE_PARM_DESC(debug, "Debug enabled or not");