Merge master.kernel.org:/pub/scm/linux/kernel/git/paulus/powerpc
[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 writting 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 writting 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         dbg("%s - port %d", __FUNCTION__, port->number);
213         if (port->write_urb_busy)
214                 return;
215
216         count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
217         if (count == 0)
218                 return;
219
220         buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
221         if (!buf) {
222                 err("%s- kzalloc(%d) failed.", __FUNCTION__,
223                     count + HCI_HEADER_LENGTH);
224                 return;
225         }
226
227         buf[0] = TX_HEADER_0;
228         buf[1] = TX_HEADER_1;
229         buf[2] = (unsigned char)count;
230         buf[3] = (unsigned char)(count >> 8);
231         serial_buf_get(priv->tx_buf,buf + HCI_HEADER_LENGTH, MAX_HCI_FRAMESIZE);
232
233         memcpy(port->write_urb->transfer_buffer, buf,
234                count + HCI_HEADER_LENGTH);
235
236         kfree(buf);
237         port->write_urb_busy = 1;
238         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
239                               count + HCI_HEADER_LENGTH,
240                               port->write_urb->transfer_buffer);
241         port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
242         port->write_urb->dev = port->serial->dev;
243         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
244
245         if (result) {
246                 dev_err(&port->dev,
247                         "%s - failed submitting write urb, error %d\n",
248                         __FUNCTION__, result);
249                 port->write_urb_busy = 0;
250         }
251
252         schedule_work(&port->work);
253 }
254
255 static void aircable_read(struct work_struct *work)
256 {
257         struct aircable_private *priv =
258                 container_of(work, struct aircable_private, rx_work);
259         struct usb_serial_port *port = priv->port;
260         struct tty_struct *tty;
261         unsigned char *data;
262         int count;
263         if (priv->rx_flags & THROTTLED){
264                 if (priv->rx_flags & ACTUALLY_THROTTLED)
265                         schedule_work(&priv->rx_work);
266                 return;
267         }
268
269         /* By now I will flush data to the tty in packages of no more than
270          * 64 bytes, to ensure I do not get throttled.
271          * Ask USB mailing list for better aproach.
272          */
273         tty = port->tty;
274
275         if (!tty) {
276                 schedule_work(&priv->rx_work);
277                 err("%s - No tty available", __FUNCTION__);
278                 return ;
279         }
280
281         count = min(64, serial_buf_data_avail(priv->rx_buf));
282
283         if (count <= 0)
284                 return; //We have finished sending everything.
285
286         tty_prepare_flip_string(tty, &data, count);
287         if (!data){
288                 err("%s- kzalloc(%d) failed.", __FUNCTION__, count);
289                 return;
290         }
291
292         serial_buf_get(priv->rx_buf, data, count);
293
294         tty_flip_buffer_push(tty);
295
296         if (serial_buf_data_avail(priv->rx_buf))
297                 schedule_work(&priv->rx_work);
298
299         return;
300 }
301 /* End of private methods */
302
303 static int aircable_probe(struct usb_serial *serial,
304                           const struct usb_device_id *id)
305 {
306         struct usb_host_interface *iface_desc = serial->interface->cur_altsetting;
307         struct usb_endpoint_descriptor *endpoint;
308         int num_bulk_out=0;
309         int i;
310
311         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
312                 endpoint = &iface_desc->endpoint[i].desc;
313                 if (usb_endpoint_is_bulk_out(endpoint)) {
314                         dbg("found bulk out on endpoint %d", i);
315                         ++num_bulk_out;
316                 }
317         }
318
319         if (num_bulk_out == 0) {
320                 dbg("Invalid interface, discarding");
321                 return -ENODEV;
322         }
323
324         return 0;
325 }
326
327 static int aircable_attach (struct usb_serial *serial)
328 {
329         struct usb_serial_port *port = serial->port[0];
330         struct aircable_private *priv;
331
332         priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
333         if (!priv){
334                 err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
335                         sizeof(struct aircable_private));
336                 return -ENOMEM;
337         }
338
339         /* Allocation of Circular Buffers */
340         priv->tx_buf = serial_buf_alloc();
341         if (priv->tx_buf == NULL) {
342                 kfree(priv);
343                 return -ENOMEM;
344         }
345
346         priv->rx_buf = serial_buf_alloc();
347         if (priv->rx_buf == NULL) {
348                 kfree(priv->tx_buf);
349                 kfree(priv);
350                 return -ENOMEM;
351         }
352
353         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
354         priv->port = port;
355         INIT_WORK(&priv->rx_work, aircable_read);
356
357         usb_set_serial_port_data(serial->port[0], priv);
358
359         return 0;
360 }
361
362 static void aircable_shutdown(struct usb_serial *serial)
363 {
364
365         struct usb_serial_port *port = serial->port[0];
366         struct aircable_private *priv = usb_get_serial_port_data(port);
367
368         dbg("%s", __FUNCTION__);
369
370         if (priv) {
371                 serial_buf_free(priv->tx_buf);
372                 serial_buf_free(priv->rx_buf);
373                 usb_set_serial_port_data(port, NULL);
374                 kfree(priv);
375         }
376 }
377
378 static int aircable_write_room(struct usb_serial_port *port)
379 {
380         struct aircable_private *priv = usb_get_serial_port_data(port);
381         return serial_buf_data_avail(priv->tx_buf);
382 }
383
384 static int aircable_write(struct usb_serial_port *port,
385                           const unsigned char *source, int count)
386 {
387         struct aircable_private *priv = usb_get_serial_port_data(port);
388         int temp;
389
390         dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
391
392         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);
393
394         if (!count){
395                 dbg("%s - write request of 0 bytes", __FUNCTION__);
396                 return count;
397         }
398
399         temp = serial_buf_put(priv->tx_buf, source, count);
400
401         aircable_send(port);
402
403         if (count > AIRCABLE_BUF_SIZE)
404                 count = AIRCABLE_BUF_SIZE;
405
406         return count;
407
408 }
409
410 static void aircable_write_bulk_callback(struct urb *urb)
411 {
412         struct usb_serial_port *port = urb->context;
413         int result;
414
415         dbg("%s - urb->status: %d", __FUNCTION__ , urb->status);
416
417         /* This has been taken from cypress_m8.c cypress_write_int_callback */
418         switch (urb->status) {
419                 case 0:
420                         /* success */
421                         break;
422                 case -ECONNRESET:
423                 case -ENOENT:
424                 case -ESHUTDOWN:
425                         /* this urb is terminated, clean up */
426                         dbg("%s - urb shutting down with status: %d",
427                             __FUNCTION__, urb->status);
428                         port->write_urb_busy = 0;
429                         return;
430                 default:
431                         /* error in the urb, so we have to resubmit it */
432                         dbg("%s - Overflow in write", __FUNCTION__);
433                         dbg("%s - nonzero write bulk status received: %d",
434                             __FUNCTION__, urb->status);
435                         port->write_urb->transfer_buffer_length = 1;
436                         port->write_urb->dev = port->serial->dev;
437                         result = usb_submit_urb(port->write_urb, GFP_KERNEL);
438                         if (result)
439                                 dev_err(&urb->dev->dev,
440                                         "%s - failed resubmitting write urb, error %d\n",
441                                         __FUNCTION__, result);
442                         else
443                                 return;
444         }
445
446         port->write_urb_busy = 0;
447
448         aircable_send(port);
449 }
450
451 static void aircable_read_bulk_callback(struct urb *urb)
452 {
453         struct usb_serial_port *port = urb->context;
454         struct aircable_private *priv = usb_get_serial_port_data(port);
455         struct tty_struct *tty;
456         unsigned long no_packages, remaining, package_length, i;
457         int result, shift = 0;
458         unsigned char *temp;
459
460         dbg("%s - port %d", __FUNCTION__, port->number);
461
462         if (urb->status) {
463                 dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
464                 if (!port->open_count) {
465                         dbg("%s - port is closed, exiting.", __FUNCTION__);
466                         return;
467                 }
468                 if (urb->status == -EPROTO) {
469                         dbg("%s - caught -EPROTO, resubmitting the urb",
470                             __FUNCTION__);
471                         usb_fill_bulk_urb(port->read_urb, port->serial->dev,
472                                           usb_rcvbulkpipe(port->serial->dev,
473                                                           port->bulk_in_endpointAddress),
474                                           port->read_urb->transfer_buffer,
475                                           port->read_urb->transfer_buffer_length,
476                                           aircable_read_bulk_callback, port);
477
478                         result = usb_submit_urb(urb, GFP_ATOMIC);
479                         if (result)
480                                 dev_err(&urb->dev->dev,
481                                         "%s - failed resubmitting read urb, error %d\n",
482                                         __FUNCTION__, result);
483                         return;
484                 }
485                 dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
486                 return;
487         }
488
489         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
490                                 urb->actual_length,urb->transfer_buffer);
491
492         tty = port->tty;
493         if (tty && urb->actual_length) {
494                 if (urb->actual_length <= 2) {
495                         /* This is an incomplete package */
496                         serial_buf_put(priv->rx_buf, urb->transfer_buffer,
497                                        urb->actual_length);
498                 } else {
499                         temp = urb->transfer_buffer;
500                         if (temp[0] == RX_HEADER_0)
501                                 shift = HCI_HEADER_LENGTH;
502
503                         remaining = urb->actual_length;
504                         no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
505
506                         if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
507                                 no_packages+=1;
508
509                         for (i = 0; i < no_packages ;i++) {
510                                 if (remaining > (HCI_COMPLETE_FRAME))
511                                         package_length = HCI_COMPLETE_FRAME;
512                                 else
513                                         package_length = remaining;
514                                 remaining -= package_length;
515
516                                 serial_buf_put(priv->rx_buf,
517                                         urb->transfer_buffer + shift +
518                                         (HCI_COMPLETE_FRAME) * (i),
519                                         package_length - shift);
520                         }
521                 }
522                 aircable_read(&priv->rx_work);
523         }
524
525         /* Schedule the next read _if_ we are still open */
526         if (port->open_count) {
527                 usb_fill_bulk_urb(port->read_urb, port->serial->dev,
528                                   usb_rcvbulkpipe(port->serial->dev,
529                                                   port->bulk_in_endpointAddress),
530                                   port->read_urb->transfer_buffer,
531                                   port->read_urb->transfer_buffer_length,
532                                   aircable_read_bulk_callback, port);
533
534                 result = usb_submit_urb(urb, GFP_ATOMIC);
535                 if (result)
536                         dev_err(&urb->dev->dev,
537                                 "%s - failed resubmitting read urb, error %d\n",
538                                 __FUNCTION__, result);
539         }
540
541         return;
542 }
543
544 /* Based on ftdi_sio.c throttle */
545 static void aircable_throttle(struct usb_serial_port *port)
546 {
547         struct aircable_private *priv = usb_get_serial_port_data(port);
548         unsigned long flags;
549
550         dbg("%s - port %d", __FUNCTION__, port->number);
551
552         spin_lock_irqsave(&priv->rx_lock, flags);
553         priv->rx_flags |= THROTTLED;
554         spin_unlock_irqrestore(&priv->rx_lock, flags);
555 }
556
557 /* Based on ftdi_sio.c unthrottle */
558 static void aircable_unthrottle(struct usb_serial_port *port)
559 {
560         struct aircable_private *priv = usb_get_serial_port_data(port);
561         int actually_throttled;
562         unsigned long flags;
563
564         dbg("%s - port %d", __FUNCTION__, port->number);
565
566         spin_lock_irqsave(&priv->rx_lock, flags);
567         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
568         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
569         spin_unlock_irqrestore(&priv->rx_lock, flags);
570
571         if (actually_throttled)
572                 schedule_work(&priv->rx_work);
573 }
574
575 static struct usb_driver aircable_driver = {
576         .name =         "aircable",
577         .probe =        usb_serial_probe,
578         .disconnect =   usb_serial_disconnect,
579         .id_table =     id_table,
580         .no_dynamic_id =        1,
581 };
582
583 static struct usb_serial_driver aircable_device = {
584         .driver = {
585                 .owner =        THIS_MODULE,
586                 .name =         "aircable",
587         },
588         .usb_driver =           &aircable_driver,
589         .id_table =             id_table,
590         .num_ports =            1,
591         .attach =               aircable_attach,
592         .probe =                aircable_probe,
593         .shutdown =             aircable_shutdown,
594         .write =                aircable_write,
595         .write_room =           aircable_write_room,
596         .write_bulk_callback =  aircable_write_bulk_callback,
597         .read_bulk_callback =   aircable_read_bulk_callback,
598         .throttle =             aircable_throttle,
599         .unthrottle =           aircable_unthrottle,
600 };
601
602 static int __init aircable_init (void)
603 {
604         int retval;
605         retval = usb_serial_register(&aircable_device);
606         if (retval)
607                 goto failed_serial_register;
608         retval = usb_register(&aircable_driver);
609         if (retval)
610                 goto failed_usb_register;
611         return 0;
612
613 failed_serial_register:
614         usb_serial_deregister(&aircable_device);
615 failed_usb_register:
616         return retval;
617 }
618
619 static void __exit aircable_exit (void)
620 {
621         usb_deregister(&aircable_driver);
622         usb_serial_deregister(&aircable_device);
623 }
624
625 MODULE_AUTHOR(DRIVER_AUTHOR);
626 MODULE_DESCRIPTION(DRIVER_DESC);
627 MODULE_VERSION(DRIVER_VERSION);
628 MODULE_LICENSE("GPL");
629
630 module_init(aircable_init);
631 module_exit(aircable_exit);
632
633 module_param(debug, bool, S_IRUGO | S_IWUSR);
634 MODULE_PARM_DESC(debug, "Debug enabled or not");