kfifo: cleanup namespace
[linux-2.6.git] / drivers / usb / serial / generic.c
1 /*
2  * USB Serial Converter Generic functions
3  *
4  * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
5  *
6  *      This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License version
8  *      2 as published by the Free Software Foundation.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/tty.h>
16 #include <linux/tty_flip.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/usb.h>
20 #include <linux/usb/serial.h>
21 #include <linux/uaccess.h>
22 #include <linux/kfifo.h>
23
24 static int debug;
25
26 #ifdef CONFIG_USB_SERIAL_GENERIC
27
28 static int generic_probe(struct usb_interface *interface,
29                          const struct usb_device_id *id);
30
31 static __u16 vendor  = 0x05f9;
32 static __u16 product = 0xffff;
33
34 module_param(vendor, ushort, 0);
35 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
36
37 module_param(product, ushort, 0);
38 MODULE_PARM_DESC(product, "User specified USB idProduct");
39
40 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
41
42 /* we want to look at all devices, as the vendor/product id can change
43  * depending on the command line argument */
44 static struct usb_device_id generic_serial_ids[] = {
45         {.driver_info = 42},
46         {}
47 };
48
49 static struct usb_driver generic_driver = {
50         .name =         "usbserial_generic",
51         .probe =        generic_probe,
52         .disconnect =   usb_serial_disconnect,
53         .id_table =     generic_serial_ids,
54         .no_dynamic_id =        1,
55 };
56
57 /* All of the device info needed for the Generic Serial Converter */
58 struct usb_serial_driver usb_serial_generic_device = {
59         .driver = {
60                 .owner =        THIS_MODULE,
61                 .name =         "generic",
62         },
63         .id_table =             generic_device_ids,
64         .usb_driver =           &generic_driver,
65         .num_ports =            1,
66         .disconnect =           usb_serial_generic_disconnect,
67         .release =              usb_serial_generic_release,
68         .throttle =             usb_serial_generic_throttle,
69         .unthrottle =           usb_serial_generic_unthrottle,
70         .resume =               usb_serial_generic_resume,
71 };
72
73 static int generic_probe(struct usb_interface *interface,
74                                const struct usb_device_id *id)
75 {
76         const struct usb_device_id *id_pattern;
77
78         id_pattern = usb_match_id(interface, generic_device_ids);
79         if (id_pattern != NULL)
80                 return usb_serial_probe(interface, id);
81         return -ENODEV;
82 }
83 #endif
84
85 int usb_serial_generic_register(int _debug)
86 {
87         int retval = 0;
88
89         debug = _debug;
90 #ifdef CONFIG_USB_SERIAL_GENERIC
91         generic_device_ids[0].idVendor = vendor;
92         generic_device_ids[0].idProduct = product;
93         generic_device_ids[0].match_flags =
94                 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
95
96         /* register our generic driver with ourselves */
97         retval = usb_serial_register(&usb_serial_generic_device);
98         if (retval)
99                 goto exit;
100         retval = usb_register(&generic_driver);
101         if (retval)
102                 usb_serial_deregister(&usb_serial_generic_device);
103 exit:
104 #endif
105         return retval;
106 }
107
108 void usb_serial_generic_deregister(void)
109 {
110 #ifdef CONFIG_USB_SERIAL_GENERIC
111         /* remove our generic driver */
112         usb_deregister(&generic_driver);
113         usb_serial_deregister(&usb_serial_generic_device);
114 #endif
115 }
116
117 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
118 {
119         struct usb_serial *serial = port->serial;
120         int result = 0;
121         unsigned long flags;
122
123         dbg("%s - port %d", __func__, port->number);
124
125         /* clear the throttle flags */
126         spin_lock_irqsave(&port->lock, flags);
127         port->throttled = 0;
128         port->throttle_req = 0;
129         spin_unlock_irqrestore(&port->lock, flags);
130
131         /* if we have a bulk endpoint, start reading from it */
132         if (serial->num_bulk_in) {
133                 /* Start reading from the device */
134                 usb_fill_bulk_urb(port->read_urb, serial->dev,
135                                    usb_rcvbulkpipe(serial->dev,
136                                                 port->bulk_in_endpointAddress),
137                                    port->read_urb->transfer_buffer,
138                                    port->read_urb->transfer_buffer_length,
139                                    ((serial->type->read_bulk_callback) ?
140                                      serial->type->read_bulk_callback :
141                                      usb_serial_generic_read_bulk_callback),
142                                    port);
143                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
144                 if (result)
145                         dev_err(&port->dev,
146                             "%s - failed resubmitting read urb, error %d\n",
147                                                         __func__, result);
148         }
149
150         return result;
151 }
152 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
153
154 static void generic_cleanup(struct usb_serial_port *port)
155 {
156         struct usb_serial *serial = port->serial;
157
158         dbg("%s - port %d", __func__, port->number);
159
160         if (serial->dev) {
161                 /* shutdown any bulk reads that might be going on */
162                 if (serial->num_bulk_out)
163                         usb_kill_urb(port->write_urb);
164                 if (serial->num_bulk_in)
165                         usb_kill_urb(port->read_urb);
166         }
167 }
168
169 void usb_serial_generic_close(struct usb_serial_port *port)
170 {
171         dbg("%s - port %d", __func__, port->number);
172         generic_cleanup(port);
173 }
174
175 static int usb_serial_multi_urb_write(struct tty_struct *tty,
176         struct usb_serial_port *port, const unsigned char *buf, int count)
177 {
178         unsigned long flags;
179         struct urb *urb;
180         unsigned char *buffer;
181         int status;
182         int towrite;
183         int bwrite = 0;
184
185         dbg("%s - port %d", __func__, port->number);
186
187         if (count == 0)
188                 dbg("%s - write request of 0 bytes", __func__);
189
190         while (count > 0) {
191                 towrite = (count > port->bulk_out_size) ?
192                         port->bulk_out_size : count;
193                 spin_lock_irqsave(&port->lock, flags);
194                 if (port->urbs_in_flight >
195                     port->serial->type->max_in_flight_urbs) {
196                         spin_unlock_irqrestore(&port->lock, flags);
197                         dbg("%s - write limit hit\n", __func__);
198                         return bwrite;
199                 }
200                 port->tx_bytes_flight += towrite;
201                 port->urbs_in_flight++;
202                 spin_unlock_irqrestore(&port->lock, flags);
203
204                 buffer = kmalloc(towrite, GFP_ATOMIC);
205                 if (!buffer) {
206                         dev_err(&port->dev,
207                         "%s ran out of kernel memory for urb ...\n", __func__);
208                         goto error_no_buffer;
209                 }
210
211                 urb = usb_alloc_urb(0, GFP_ATOMIC);
212                 if (!urb) {
213                         dev_err(&port->dev, "%s - no more free urbs\n",
214                                 __func__);
215                         goto error_no_urb;
216                 }
217
218                 /* Copy data */
219                 memcpy(buffer, buf + bwrite, towrite);
220                 usb_serial_debug_data(debug, &port->dev, __func__,
221                                       towrite, buffer);
222                 /* fill the buffer and send it */
223                 usb_fill_bulk_urb(urb, port->serial->dev,
224                         usb_sndbulkpipe(port->serial->dev,
225                                         port->bulk_out_endpointAddress),
226                         buffer, towrite,
227                         usb_serial_generic_write_bulk_callback, port);
228
229                 status = usb_submit_urb(urb, GFP_ATOMIC);
230                 if (status) {
231                         dev_err(&port->dev,
232                                 "%s - failed submitting write urb, error %d\n",
233                                 __func__, status);
234                         goto error;
235                 }
236
237                 /* This urb is the responsibility of the host driver now */
238                 usb_free_urb(urb);
239                 dbg("%s write: %d", __func__, towrite);
240                 count -= towrite;
241                 bwrite += towrite;
242         }
243         return bwrite;
244
245 error:
246         usb_free_urb(urb);
247 error_no_urb:
248         kfree(buffer);
249 error_no_buffer:
250         spin_lock_irqsave(&port->lock, flags);
251         port->urbs_in_flight--;
252         port->tx_bytes_flight -= towrite;
253         spin_unlock_irqrestore(&port->lock, flags);
254         return bwrite;
255 }
256
257 /**
258  * usb_serial_generic_write_start - kick off an URB write
259  * @port:       Pointer to the &struct usb_serial_port data
260  *
261  * Returns the number of bytes queued on success. This will be zero if there
262  * was nothing to send. Otherwise, it returns a negative errno value
263  */
264 static int usb_serial_generic_write_start(struct usb_serial_port *port)
265 {
266         struct usb_serial *serial = port->serial;
267         unsigned char *data;
268         int result;
269         int count;
270         unsigned long flags;
271         bool start_io;
272
273         /* Atomically determine whether we can and need to start a USB
274          * operation. */
275         spin_lock_irqsave(&port->lock, flags);
276         if (port->write_urb_busy)
277                 start_io = false;
278         else {
279                 start_io = (kfifo_len(port->write_fifo) != 0);
280                 port->write_urb_busy = start_io;
281         }
282         spin_unlock_irqrestore(&port->lock, flags);
283
284         if (!start_io)
285                 return 0;
286
287         data = port->write_urb->transfer_buffer;
288         count = kfifo_get_locked(port->write_fifo, data, port->bulk_out_size, &port->lock);
289         usb_serial_debug_data(debug, &port->dev, __func__, count, data);
290
291         /* set up our urb */
292         usb_fill_bulk_urb(port->write_urb, serial->dev,
293                            usb_sndbulkpipe(serial->dev,
294                                 port->bulk_out_endpointAddress),
295                            port->write_urb->transfer_buffer, count,
296                            ((serial->type->write_bulk_callback) ?
297                              serial->type->write_bulk_callback :
298                              usb_serial_generic_write_bulk_callback),
299                            port);
300
301         /* send the data out the bulk port */
302         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
303         if (result) {
304                 dev_err(&port->dev,
305                         "%s - failed submitting write urb, error %d\n",
306                                                 __func__, result);
307                 /* don't have to grab the lock here, as we will
308                    retry if != 0 */
309                 port->write_urb_busy = 0;
310         } else
311                 result = count;
312
313         return result;
314 }
315
316 /**
317  * usb_serial_generic_write - generic write function for serial USB devices
318  * @tty:        Pointer to &struct tty_struct for the device
319  * @port:       Pointer to the &usb_serial_port structure for the device
320  * @buf:        Pointer to the data to write
321  * @count:      Number of bytes to write
322  *
323  * Returns the number of characters actually written, which may be anything
324  * from zero to @count. If an error occurs, it returns the negative errno
325  * value.
326  */
327 int usb_serial_generic_write(struct tty_struct *tty,
328         struct usb_serial_port *port, const unsigned char *buf, int count)
329 {
330         struct usb_serial *serial = port->serial;
331         int result;
332
333         dbg("%s - port %d", __func__, port->number);
334
335         if (count == 0) {
336                 dbg("%s - write request of 0 bytes", __func__);
337                 return 0;
338         }
339
340         /* only do something if we have a bulk out endpoint */
341         if (!serial->num_bulk_out)
342                 return 0;
343
344         if (serial->type->max_in_flight_urbs)
345                 return usb_serial_multi_urb_write(tty, port,
346                                                   buf, count);
347
348         count = kfifo_put_locked(port->write_fifo, buf, count, &port->lock);
349         result = usb_serial_generic_write_start(port);
350
351         if (result >= 0)
352                 result = count;
353
354         return result;
355 }
356 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
357
358 int usb_serial_generic_write_room(struct tty_struct *tty)
359 {
360         struct usb_serial_port *port = tty->driver_data;
361         struct usb_serial *serial = port->serial;
362         unsigned long flags;
363         int room = 0;
364
365         dbg("%s - port %d", __func__, port->number);
366         spin_lock_irqsave(&port->lock, flags);
367         if (serial->type->max_in_flight_urbs) {
368                 if (port->urbs_in_flight < serial->type->max_in_flight_urbs)
369                         room = port->bulk_out_size *
370                                 (serial->type->max_in_flight_urbs -
371                                  port->urbs_in_flight);
372         } else if (serial->num_bulk_out)
373                 room = port->write_fifo->size - kfifo_len(port->write_fifo);
374         spin_unlock_irqrestore(&port->lock, flags);
375
376         dbg("%s - returns %d", __func__, room);
377         return room;
378 }
379
380 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
381 {
382         struct usb_serial_port *port = tty->driver_data;
383         struct usb_serial *serial = port->serial;
384         int chars = 0;
385         unsigned long flags;
386
387         dbg("%s - port %d", __func__, port->number);
388
389         if (serial->type->max_in_flight_urbs) {
390                 spin_lock_irqsave(&port->lock, flags);
391                 chars = port->tx_bytes_flight;
392                 spin_unlock_irqrestore(&port->lock, flags);
393         } else if (serial->num_bulk_out)
394                 chars = kfifo_len(port->write_fifo);
395
396         dbg("%s - returns %d", __func__, chars);
397         return chars;
398 }
399
400
401 void usb_serial_generic_resubmit_read_urb(struct usb_serial_port *port,
402                         gfp_t mem_flags)
403 {
404         struct urb *urb = port->read_urb;
405         struct usb_serial *serial = port->serial;
406         int result;
407
408         /* Continue reading from device */
409         usb_fill_bulk_urb(urb, serial->dev,
410                            usb_rcvbulkpipe(serial->dev,
411                                         port->bulk_in_endpointAddress),
412                            urb->transfer_buffer,
413                            urb->transfer_buffer_length,
414                            ((serial->type->read_bulk_callback) ?
415                              serial->type->read_bulk_callback :
416                              usb_serial_generic_read_bulk_callback), port);
417         result = usb_submit_urb(urb, mem_flags);
418         if (result)
419                 dev_err(&port->dev,
420                         "%s - failed resubmitting read urb, error %d\n",
421                                                         __func__, result);
422 }
423 EXPORT_SYMBOL_GPL(usb_serial_generic_resubmit_read_urb);
424
425 /* Push data to tty layer and resubmit the bulk read URB */
426 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
427 {
428         struct urb *urb = port->read_urb;
429         struct tty_struct *tty = tty_port_tty_get(&port->port);
430         char *ch = (char *)urb->transfer_buffer;
431         int i;
432
433         if (!tty)
434                 goto done;
435
436         /* The per character mucking around with sysrq path it too slow for
437            stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
438            where the USB serial is not a console anyway */
439         if (!port->console || !port->sysrq)
440                 tty_insert_flip_string(tty, ch, urb->actual_length);
441         else {
442                 /* Push data to tty */
443                 for (i = 0; i < urb->actual_length; i++, ch++) {
444                         if (!usb_serial_handle_sysrq_char(tty, port, *ch))
445                                 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
446                 }
447         }
448         tty_flip_buffer_push(tty);
449         tty_kref_put(tty);
450 done:
451         usb_serial_generic_resubmit_read_urb(port, GFP_ATOMIC);
452 }
453
454 void usb_serial_generic_read_bulk_callback(struct urb *urb)
455 {
456         struct usb_serial_port *port = urb->context;
457         unsigned char *data = urb->transfer_buffer;
458         int status = urb->status;
459         unsigned long flags;
460
461         dbg("%s - port %d", __func__, port->number);
462
463         if (unlikely(status != 0)) {
464                 dbg("%s - nonzero read bulk status received: %d",
465                     __func__, status);
466                 return;
467         }
468
469         usb_serial_debug_data(debug, &port->dev, __func__,
470                                                 urb->actual_length, data);
471
472         /* Throttle the device if requested by tty */
473         spin_lock_irqsave(&port->lock, flags);
474         port->throttled = port->throttle_req;
475         if (!port->throttled) {
476                 spin_unlock_irqrestore(&port->lock, flags);
477                 flush_and_resubmit_read_urb(port);
478         } else
479                 spin_unlock_irqrestore(&port->lock, flags);
480 }
481 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
482
483 void usb_serial_generic_write_bulk_callback(struct urb *urb)
484 {
485         unsigned long flags;
486         struct usb_serial_port *port = urb->context;
487         int status = urb->status;
488
489         dbg("%s - port %d", __func__, port->number);
490
491         if (port->serial->type->max_in_flight_urbs) {
492                 spin_lock_irqsave(&port->lock, flags);
493                 --port->urbs_in_flight;
494                 port->tx_bytes_flight -= urb->transfer_buffer_length;
495                 if (port->urbs_in_flight < 0)
496                         port->urbs_in_flight = 0;
497                 spin_unlock_irqrestore(&port->lock, flags);
498
499                 if (status) {
500                         dbg("%s - nonzero multi-urb write bulk status "
501                                 "received: %d", __func__, status);
502                         return;
503                 }
504         } else {
505                 port->write_urb_busy = 0;
506
507                 if (status) {
508                         dbg("%s - nonzero multi-urb write bulk status "
509                                 "received: %d", __func__, status);
510                         kfifo_reset(port->write_fifo);
511                 } else
512                         usb_serial_generic_write_start(port);
513         }
514
515         usb_serial_port_softint(port);
516 }
517 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
518
519 void usb_serial_generic_throttle(struct tty_struct *tty)
520 {
521         struct usb_serial_port *port = tty->driver_data;
522         unsigned long flags;
523
524         dbg("%s - port %d", __func__, port->number);
525
526         /* Set the throttle request flag. It will be picked up
527          * by usb_serial_generic_read_bulk_callback(). */
528         spin_lock_irqsave(&port->lock, flags);
529         port->throttle_req = 1;
530         spin_unlock_irqrestore(&port->lock, flags);
531 }
532
533 void usb_serial_generic_unthrottle(struct tty_struct *tty)
534 {
535         struct usb_serial_port *port = tty->driver_data;
536         int was_throttled;
537         unsigned long flags;
538
539         dbg("%s - port %d", __func__, port->number);
540
541         /* Clear the throttle flags */
542         spin_lock_irqsave(&port->lock, flags);
543         was_throttled = port->throttled;
544         port->throttled = port->throttle_req = 0;
545         spin_unlock_irqrestore(&port->lock, flags);
546
547         if (was_throttled) {
548                 /* Resume reading from device */
549                 flush_and_resubmit_read_urb(port);
550         }
551 }
552
553 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
554                         struct usb_serial_port *port, unsigned int ch)
555 {
556         if (port->sysrq && port->console) {
557                 if (ch && time_before(jiffies, port->sysrq)) {
558                         handle_sysrq(ch, tty);
559                         port->sysrq = 0;
560                         return 1;
561                 }
562                 port->sysrq = 0;
563         }
564         return 0;
565 }
566 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
567
568 int usb_serial_handle_break(struct usb_serial_port *port)
569 {
570         if (!port->sysrq) {
571                 port->sysrq = jiffies + HZ*5;
572                 return 1;
573         }
574         port->sysrq = 0;
575         return 0;
576 }
577 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
578
579 int usb_serial_generic_resume(struct usb_serial *serial)
580 {
581         struct usb_serial_port *port;
582         int i, c = 0, r;
583
584         for (i = 0; i < serial->num_ports; i++) {
585                 port = serial->port[i];
586                 if (!port->port.count)
587                         continue;
588
589                 if (port->read_urb) {
590                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
591                         if (r < 0)
592                                 c++;
593                 }
594
595                 if (port->write_urb) {
596                         r = usb_serial_generic_write_start(port);
597                         if (r < 0)
598                                 c++;
599                 }
600         }
601
602         return c ? -EIO : 0;
603 }
604 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
605
606 void usb_serial_generic_disconnect(struct usb_serial *serial)
607 {
608         int i;
609
610         dbg("%s", __func__);
611
612         /* stop reads and writes on all ports */
613         for (i = 0; i < serial->num_ports; ++i)
614                 generic_cleanup(serial->port[i]);
615 }
616
617 void usb_serial_generic_release(struct usb_serial *serial)
618 {
619         dbg("%s", __func__);
620 }