USB: serial: remove unnecessary bulk-urb re-fills
[cascardo/linux.git] / drivers / usb / serial / cyberjack.c
1 /*
2  *  REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver
3  *
4  *  Copyright (C) 2001  REINER SCT
5  *  Author: Matthias Bruestle
6  *
7  *  Contact: support@reiner-sct.com (see MAINTAINERS)
8  *
9  *  This program is largely derived from work by the linux-usb group
10  *  and associated source files.  Please see the usb/serial files for
11  *  individual credits and copyrights.
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or
16  *  (at your option) any later version.
17  *
18  *  Thanks to Greg Kroah-Hartman (greg@kroah.com) for his help and
19  *  patience.
20  *
21  *  In case of problems, please write to the contact e-mail address
22  *  mentioned above.
23  *
24  *  Please note that later models of the cyberjack reader family are
25  *  supported by a libusb-based userspace device driver.
26  *
27  *  Homepage: http://www.reiner-sct.de/support/treiber_cyberjack.php#linux
28  */
29
30
31 #include <linux/kernel.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/slab.h>
35 #include <linux/tty.h>
36 #include <linux/tty_driver.h>
37 #include <linux/tty_flip.h>
38 #include <linux/module.h>
39 #include <linux/spinlock.h>
40 #include <linux/uaccess.h>
41 #include <linux/usb.h>
42 #include <linux/usb/serial.h>
43
44 #define CYBERJACK_LOCAL_BUF_SIZE 32
45
46 static int debug;
47
48 /*
49  * Version Information
50  */
51 #define DRIVER_VERSION "v1.01"
52 #define DRIVER_AUTHOR "Matthias Bruestle"
53 #define DRIVER_DESC "REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver"
54
55
56 #define CYBERJACK_VENDOR_ID     0x0C4B
57 #define CYBERJACK_PRODUCT_ID    0x0100
58
59 /* Function prototypes */
60 static int cyberjack_startup(struct usb_serial *serial);
61 static void cyberjack_disconnect(struct usb_serial *serial);
62 static void cyberjack_release(struct usb_serial *serial);
63 static int  cyberjack_open(struct tty_struct *tty,
64         struct usb_serial_port *port);
65 static void cyberjack_close(struct usb_serial_port *port);
66 static int cyberjack_write(struct tty_struct *tty,
67         struct usb_serial_port *port, const unsigned char *buf, int count);
68 static int cyberjack_write_room(struct tty_struct *tty);
69 static void cyberjack_read_int_callback(struct urb *urb);
70 static void cyberjack_read_bulk_callback(struct urb *urb);
71 static void cyberjack_write_bulk_callback(struct urb *urb);
72
73 static const struct usb_device_id id_table[] = {
74         { USB_DEVICE(CYBERJACK_VENDOR_ID, CYBERJACK_PRODUCT_ID) },
75         { }                     /* Terminating entry */
76 };
77
78 MODULE_DEVICE_TABLE(usb, id_table);
79
80 static struct usb_driver cyberjack_driver = {
81         .name =         "cyberjack",
82         .probe =        usb_serial_probe,
83         .disconnect =   usb_serial_disconnect,
84         .id_table =     id_table,
85         .no_dynamic_id =        1,
86 };
87
88 static struct usb_serial_driver cyberjack_device = {
89         .driver = {
90                 .owner =        THIS_MODULE,
91                 .name =         "cyberjack",
92         },
93         .description =          "Reiner SCT Cyberjack USB card reader",
94         .usb_driver =           &cyberjack_driver,
95         .id_table =             id_table,
96         .num_ports =            1,
97         .attach =               cyberjack_startup,
98         .disconnect =           cyberjack_disconnect,
99         .release =              cyberjack_release,
100         .open =                 cyberjack_open,
101         .close =                cyberjack_close,
102         .write =                cyberjack_write,
103         .write_room =           cyberjack_write_room,
104         .read_int_callback =    cyberjack_read_int_callback,
105         .read_bulk_callback =   cyberjack_read_bulk_callback,
106         .write_bulk_callback =  cyberjack_write_bulk_callback,
107 };
108
109 struct cyberjack_private {
110         spinlock_t      lock;           /* Lock for SMP */
111         short           rdtodo;         /* Bytes still to read */
112         unsigned char   wrbuf[5*64];    /* Buffer for collecting data to write */
113         short           wrfilled;       /* Overall data size we already got */
114         short           wrsent;         /* Data already sent */
115 };
116
117 /* do some startup allocations not currently performed by usb_serial_probe() */
118 static int cyberjack_startup(struct usb_serial *serial)
119 {
120         struct cyberjack_private *priv;
121         int i;
122
123         dbg("%s", __func__);
124
125         /* allocate the private data structure */
126         priv = kmalloc(sizeof(struct cyberjack_private), GFP_KERNEL);
127         if (!priv)
128                 return -ENOMEM;
129
130         /* set initial values */
131         spin_lock_init(&priv->lock);
132         priv->rdtodo = 0;
133         priv->wrfilled = 0;
134         priv->wrsent = 0;
135         usb_set_serial_port_data(serial->port[0], priv);
136
137         init_waitqueue_head(&serial->port[0]->write_wait);
138
139         for (i = 0; i < serial->num_ports; ++i) {
140                 int result;
141                 result = usb_submit_urb(serial->port[i]->interrupt_in_urb,
142                                         GFP_KERNEL);
143                 if (result)
144                         dev_err(&serial->dev->dev,
145                                 "usb_submit_urb(read int) failed\n");
146                 dbg("%s - usb_submit_urb(int urb)", __func__);
147         }
148
149         return 0;
150 }
151
152 static void cyberjack_disconnect(struct usb_serial *serial)
153 {
154         int i;
155
156         dbg("%s", __func__);
157
158         for (i = 0; i < serial->num_ports; ++i)
159                 usb_kill_urb(serial->port[i]->interrupt_in_urb);
160 }
161
162 static void cyberjack_release(struct usb_serial *serial)
163 {
164         int i;
165
166         dbg("%s", __func__);
167
168         for (i = 0; i < serial->num_ports; ++i) {
169                 /* My special items, the standard routines free my urbs */
170                 kfree(usb_get_serial_port_data(serial->port[i]));
171         }
172 }
173
174 static int  cyberjack_open(struct tty_struct *tty,
175                                         struct usb_serial_port *port)
176 {
177         struct cyberjack_private *priv;
178         unsigned long flags;
179         int result = 0;
180
181         dbg("%s - port %d", __func__, port->number);
182
183         dbg("%s - usb_clear_halt", __func__);
184         usb_clear_halt(port->serial->dev, port->write_urb->pipe);
185
186         priv = usb_get_serial_port_data(port);
187         spin_lock_irqsave(&priv->lock, flags);
188         priv->rdtodo = 0;
189         priv->wrfilled = 0;
190         priv->wrsent = 0;
191         spin_unlock_irqrestore(&priv->lock, flags);
192
193         return result;
194 }
195
196 static void cyberjack_close(struct usb_serial_port *port)
197 {
198         dbg("%s - port %d", __func__, port->number);
199
200         if (port->serial->dev) {
201                 /* shutdown any bulk reads that might be going on */
202                 usb_kill_urb(port->write_urb);
203                 usb_kill_urb(port->read_urb);
204         }
205 }
206
207 static int cyberjack_write(struct tty_struct *tty,
208         struct usb_serial_port *port, const unsigned char *buf, int count)
209 {
210         struct cyberjack_private *priv = usb_get_serial_port_data(port);
211         unsigned long flags;
212         int result;
213         int wrexpected;
214
215         dbg("%s - port %d", __func__, port->number);
216
217         if (count == 0) {
218                 dbg("%s - write request of 0 bytes", __func__);
219                 return 0;
220         }
221
222         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
223                 dbg("%s - already writing", __func__);
224                 return 0;
225         }
226
227         spin_lock_irqsave(&priv->lock, flags);
228
229         if (count+priv->wrfilled > sizeof(priv->wrbuf)) {
230                 /* To much data for buffer. Reset buffer. */
231                 priv->wrfilled = 0;
232                 spin_unlock_irqrestore(&priv->lock, flags);
233                 set_bit(0, &port->write_urbs_free);
234                 return 0;
235         }
236
237         /* Copy data */
238         memcpy(priv->wrbuf + priv->wrfilled, buf, count);
239
240         usb_serial_debug_data(debug, &port->dev, __func__, count,
241                 priv->wrbuf + priv->wrfilled);
242         priv->wrfilled += count;
243
244         if (priv->wrfilled >= 3) {
245                 wrexpected = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
246                 dbg("%s - expected data: %d", __func__, wrexpected);
247         } else
248                 wrexpected = sizeof(priv->wrbuf);
249
250         if (priv->wrfilled >= wrexpected) {
251                 /* We have enough data to begin transmission */
252                 int length;
253
254                 dbg("%s - transmitting data (frame 1)", __func__);
255                 length = (wrexpected > port->bulk_out_size) ?
256                                         port->bulk_out_size : wrexpected;
257
258                 memcpy(port->write_urb->transfer_buffer, priv->wrbuf, length);
259                 priv->wrsent = length;
260
261                 /* set up our urb */
262                 port->write_urb->transfer_buffer_length = length;
263
264                 /* send the data out the bulk port */
265                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
266                 if (result) {
267                         dev_err(&port->dev,
268                                 "%s - failed submitting write urb, error %d",
269                                 __func__, result);
270                         /* Throw away data. No better idea what to do with it. */
271                         priv->wrfilled = 0;
272                         priv->wrsent = 0;
273                         spin_unlock_irqrestore(&priv->lock, flags);
274                         set_bit(0, &port->write_urbs_free);
275                         return 0;
276                 }
277
278                 dbg("%s - priv->wrsent=%d", __func__, priv->wrsent);
279                 dbg("%s - priv->wrfilled=%d", __func__, priv->wrfilled);
280
281                 if (priv->wrsent >= priv->wrfilled) {
282                         dbg("%s - buffer cleaned", __func__);
283                         memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
284                         priv->wrfilled = 0;
285                         priv->wrsent = 0;
286                 }
287         }
288
289         spin_unlock_irqrestore(&priv->lock, flags);
290
291         return count;
292 }
293
294 static int cyberjack_write_room(struct tty_struct *tty)
295 {
296         /* FIXME: .... */
297         return CYBERJACK_LOCAL_BUF_SIZE;
298 }
299
300 static void cyberjack_read_int_callback(struct urb *urb)
301 {
302         struct usb_serial_port *port = urb->context;
303         struct cyberjack_private *priv = usb_get_serial_port_data(port);
304         unsigned char *data = urb->transfer_buffer;
305         int status = urb->status;
306         int result;
307
308         dbg("%s - port %d", __func__, port->number);
309
310         /* the urb might have been killed. */
311         if (status)
312                 return;
313
314         usb_serial_debug_data(debug, &port->dev, __func__,
315                                                 urb->actual_length, data);
316
317         /* React only to interrupts signaling a bulk_in transfer */
318         if (urb->actual_length == 4 && data[0] == 0x01) {
319                 short old_rdtodo;
320
321                 /* This is a announcement of coming bulk_ins. */
322                 unsigned short size = ((unsigned short)data[3]<<8)+data[2]+3;
323
324                 spin_lock(&priv->lock);
325
326                 old_rdtodo = priv->rdtodo;
327
328                 if (old_rdtodo + size < old_rdtodo) {
329                         dbg("To many bulk_in urbs to do.");
330                         spin_unlock(&priv->lock);
331                         goto resubmit;
332                 }
333
334                 /* "+=" is probably more fault tollerant than "=" */
335                 priv->rdtodo += size;
336
337                 dbg("%s - rdtodo: %d", __func__, priv->rdtodo);
338
339                 spin_unlock(&priv->lock);
340
341                 if (!old_rdtodo) {
342                         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
343                         if (result)
344                                 dev_err(&port->dev, "%s - failed resubmitting "
345                                         "read urb, error %d\n",
346                                         __func__, result);
347                         dbg("%s - usb_submit_urb(read urb)", __func__);
348                 }
349         }
350
351 resubmit:
352         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
353         if (result)
354                 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
355         dbg("%s - usb_submit_urb(int urb)", __func__);
356 }
357
358 static void cyberjack_read_bulk_callback(struct urb *urb)
359 {
360         struct usb_serial_port *port = urb->context;
361         struct cyberjack_private *priv = usb_get_serial_port_data(port);
362         struct tty_struct *tty;
363         unsigned char *data = urb->transfer_buffer;
364         short todo;
365         int result;
366         int status = urb->status;
367
368         dbg("%s - port %d", __func__, port->number);
369
370         usb_serial_debug_data(debug, &port->dev, __func__,
371                                                 urb->actual_length, data);
372         if (status) {
373                 dbg("%s - nonzero read bulk status received: %d",
374                     __func__, status);
375                 return;
376         }
377
378         tty = tty_port_tty_get(&port->port);
379         if (!tty) {
380                 dbg("%s - ignoring since device not open", __func__);
381                 return;
382         }
383         if (urb->actual_length) {
384                 tty_insert_flip_string(tty, data, urb->actual_length);
385                 tty_flip_buffer_push(tty);
386         }
387         tty_kref_put(tty);
388
389         spin_lock(&priv->lock);
390
391         /* Reduce urbs to do by one. */
392         priv->rdtodo -= urb->actual_length;
393         /* Just to be sure */
394         if (priv->rdtodo < 0)
395                 priv->rdtodo = 0;
396         todo = priv->rdtodo;
397
398         spin_unlock(&priv->lock);
399
400         dbg("%s - rdtodo: %d", __func__, todo);
401
402         /* Continue to read if we have still urbs to do. */
403         if (todo /* || (urb->actual_length==port->bulk_in_endpointAddress)*/) {
404                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
405                 if (result)
406                         dev_err(&port->dev, "%s - failed resubmitting read "
407                                 "urb, error %d\n", __func__, result);
408                 dbg("%s - usb_submit_urb(read urb)", __func__);
409         }
410 }
411
412 static void cyberjack_write_bulk_callback(struct urb *urb)
413 {
414         struct usb_serial_port *port = urb->context;
415         struct cyberjack_private *priv = usb_get_serial_port_data(port);
416         int status = urb->status;
417
418         dbg("%s - port %d", __func__, port->number);
419
420         set_bit(0, &port->write_urbs_free);
421         if (status) {
422                 dbg("%s - nonzero write bulk status received: %d",
423                     __func__, status);
424                 return;
425         }
426
427         spin_lock(&priv->lock);
428
429         /* only do something if we have more data to send */
430         if (priv->wrfilled) {
431                 int length, blksize, result;
432
433                 dbg("%s - transmitting data (frame n)", __func__);
434
435                 length = ((priv->wrfilled - priv->wrsent) > port->bulk_out_size) ?
436                         port->bulk_out_size : (priv->wrfilled - priv->wrsent);
437
438                 memcpy(port->write_urb->transfer_buffer,
439                                         priv->wrbuf + priv->wrsent, length);
440                 priv->wrsent += length;
441
442                 /* set up our urb */
443                 port->write_urb->transfer_buffer_length = length;
444
445                 /* send the data out the bulk port */
446                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
447                 if (result) {
448                         dev_err(&port->dev,
449                                 "%s - failed submitting write urb, error %d\n",
450                                 __func__, result);
451                         /* Throw away data. No better idea what to do with it. */
452                         priv->wrfilled = 0;
453                         priv->wrsent = 0;
454                         goto exit;
455                 }
456
457                 dbg("%s - priv->wrsent=%d", __func__, priv->wrsent);
458                 dbg("%s - priv->wrfilled=%d", __func__, priv->wrfilled);
459
460                 blksize = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
461
462                 if (priv->wrsent >= priv->wrfilled ||
463                                         priv->wrsent >= blksize) {
464                         dbg("%s - buffer cleaned", __func__);
465                         memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
466                         priv->wrfilled = 0;
467                         priv->wrsent = 0;
468                 }
469         }
470
471 exit:
472         spin_unlock(&priv->lock);
473         usb_serial_port_softint(port);
474 }
475
476 static int __init cyberjack_init(void)
477 {
478         int retval;
479         retval  = usb_serial_register(&cyberjack_device);
480         if (retval)
481                 goto failed_usb_serial_register;
482         retval = usb_register(&cyberjack_driver);
483         if (retval)
484                 goto failed_usb_register;
485
486         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION " "
487                DRIVER_AUTHOR "\n");
488         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
489
490         return 0;
491 failed_usb_register:
492         usb_serial_deregister(&cyberjack_device);
493 failed_usb_serial_register:
494         return retval;
495 }
496
497 static void __exit cyberjack_exit(void)
498 {
499         usb_deregister(&cyberjack_driver);
500         usb_serial_deregister(&cyberjack_device);
501 }
502
503 module_init(cyberjack_init);
504 module_exit(cyberjack_exit);
505
506 MODULE_AUTHOR(DRIVER_AUTHOR);
507 MODULE_DESCRIPTION(DRIVER_DESC);
508 MODULE_VERSION(DRIVER_VERSION);
509 MODULE_LICENSE("GPL");
510
511 module_param(debug, bool, S_IRUGO | S_IWUSR);
512 MODULE_PARM_DESC(debug, "Debug enabled or not");