USB: usblp: add dynamic URBs, fix races
[linux-2.6.git] / drivers / usb / class / usblp.c
1 /*
2  * usblp.c
3  *
4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
5  * Copyright (c) 1999 Pavel Machek      <pavel@suse.cz>
6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
11  *
12  * USB Printer Device Class driver for USB printers and printer cables
13  *
14  * Sponsored by SuSE
15  *
16  * ChangeLog:
17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
18  *      v0.2 - some more cleanups
19  *      v0.3 - cleaner again, waitqueue fixes
20  *      v0.4 - fixes in unidirectional mode
21  *      v0.5 - add DEVICE_ID string support
22  *      v0.6 - never time out
23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
24  *      v0.8 - add devfs support
25  *      v0.9 - fix unplug-while-open paths
26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
27  *      v0.11 - add proto_bias option (Pete Zaitcev)
28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
30  *              use usb_buffer_alloc() for read buf & write buf;
31  */
32
33 /*
34  * This program is free software; you can redistribute it and/or modify
35  * it under the terms of the GNU General Public License as published by
36  * the Free Software Foundation; either version 2 of the License, or
37  * (at your option) any later version.
38  *
39  * This program is distributed in the hope that it will be useful,
40  * but WITHOUT ANY WARRANTY; without even the implied warranty of
41  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
42  * GNU General Public License for more details.
43  *
44  * You should have received a copy of the GNU General Public License
45  * along with this program; if not, write to the Free Software
46  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
47  */
48
49 #include <linux/module.h>
50 #include <linux/kernel.h>
51 #include <linux/sched.h>
52 #include <linux/signal.h>
53 #include <linux/poll.h>
54 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/lp.h>
57 #include <linux/mutex.h>
58 #undef DEBUG
59 #include <linux/usb.h>
60
61 /*
62  * Version Information
63  */
64 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
65 #define DRIVER_DESC "USB Printer Device Class driver"
66
67 #define USBLP_BUF_SIZE          8192
68 #define USBLP_BUF_SIZE_IN       1024
69 #define USBLP_DEVICE_ID_SIZE    1024
70
71 /* ioctls: */
72 #define LPGETSTATUS             0x060b          /* same as in drivers/char/lp.c */
73 #define IOCNR_GET_DEVICE_ID             1
74 #define IOCNR_GET_PROTOCOLS             2
75 #define IOCNR_SET_PROTOCOL              3
76 #define IOCNR_HP_SET_CHANNEL            4
77 #define IOCNR_GET_BUS_ADDRESS           5
78 #define IOCNR_GET_VID_PID               6
79 #define IOCNR_SOFT_RESET                7
80 /* Get device_id string: */
81 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
82 /* The following ioctls were added for http://hpoj.sourceforge.net: */
83 /* Get two-int array:
84  * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
85  * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
86 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
87 /* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
88 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
89 /* Set channel number (HP Vendor-specific command): */
90 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
91 /* Get two-int array: [0]=bus number, [1]=device address: */
92 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
93 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
94 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
95 /* Perform class specific soft reset */
96 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
97
98 /*
99  * A DEVICE_ID string may include the printer's serial number.
100  * It should end with a semi-colon (';').
101  * An example from an HP 970C DeskJet printer is (this is one long string,
102  * with the serial number changed):
103 MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
104  */
105
106 /*
107  * USB Printer Requests
108  */
109
110 #define USBLP_REQ_GET_ID                        0x00
111 #define USBLP_REQ_GET_STATUS                    0x01
112 #define USBLP_REQ_RESET                         0x02
113 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
114
115 #define USBLP_MINORS            16
116 #define USBLP_MINOR_BASE        0
117
118 #define USBLP_WRITE_TIMEOUT     (5000)                  /* 5 seconds */
119
120 #define USBLP_FIRST_PROTOCOL    1
121 #define USBLP_LAST_PROTOCOL     3
122 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
123
124 /*
125  * some arbitrary status buffer size;
126  * need a status buffer that is allocated via kmalloc(), not on stack
127  */
128 #define STATUS_BUF_SIZE         8
129
130 /*
131  * Locks down the locking order:
132  * ->wmut locks wstatus.
133  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
134  * [rw]status. We only touch status when we know the side idle.
135  * ->lock locks what interrupt accesses.
136  */
137 struct usblp {
138         struct usb_device       *dev;                   /* USB device */
139         struct mutex            wmut;
140         struct mutex            mut;
141         spinlock_t              lock;           /* locks rcomplete, wcomplete */
142         char                    *readbuf;               /* read transfer_buffer */
143         char                    *statusbuf;             /* status transfer_buffer */
144         struct usb_anchor       urbs;
145         wait_queue_head_t       rwait, wwait;
146         int                     readcount;              /* Counter for reads */
147         int                     ifnum;                  /* Interface number */
148         struct usb_interface    *intf;                  /* The interface */
149         /* Alternate-setting numbers and endpoints for each protocol
150          * (7/1/{index=1,2,3}) that the device supports: */
151         struct {
152                 int                             alt_setting;
153                 struct usb_endpoint_descriptor  *epwrite;
154                 struct usb_endpoint_descriptor  *epread;
155         }                       protocol[USBLP_MAX_PROTOCOLS];
156         int                     current_protocol;
157         int                     minor;                  /* minor number of device */
158         int                     wcomplete, rcomplete;
159         int                     wstatus;        /* bytes written or error */
160         int                     rstatus;        /* bytes ready or error */
161         unsigned int            quirks;                 /* quirks flags */
162         unsigned char           used;                   /* True if open */
163         unsigned char           present;                /* True if not disconnected */
164         unsigned char           bidir;                  /* interface is bidirectional */
165         unsigned char           sleeping;               /* interface is suspended */
166         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
167                                                         /* first 2 bytes are (big-endian) length */
168 };
169
170 #ifdef DEBUG
171 static void usblp_dump(struct usblp *usblp) {
172         int p;
173
174         dbg("usblp=0x%p", usblp);
175         dbg("dev=0x%p", usblp->dev);
176         dbg("present=%d", usblp->present);
177         dbg("readbuf=0x%p", usblp->readbuf);
178         dbg("readcount=%d", usblp->readcount);
179         dbg("ifnum=%d", usblp->ifnum);
180     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
181         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
182         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
183         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
184     }
185         dbg("current_protocol=%d", usblp->current_protocol);
186         dbg("minor=%d", usblp->minor);
187         dbg("wstatus=%d", usblp->wstatus);
188         dbg("rstatus=%d", usblp->rstatus);
189         dbg("quirks=%d", usblp->quirks);
190         dbg("used=%d", usblp->used);
191         dbg("bidir=%d", usblp->bidir);
192         dbg("sleeping=%d", usblp->sleeping);
193         dbg("device_id_string=\"%s\"",
194                 usblp->device_id_string ?
195                         usblp->device_id_string + 2 :
196                         (unsigned char *)"(null)");
197 }
198 #endif
199
200 /* Quirks: various printer quirks are handled by this table & its flags. */
201
202 struct quirk_printer_struct {
203         __u16 vendorId;
204         __u16 productId;
205         unsigned int quirks;
206 };
207
208 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
209 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
210 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
211
212 static const struct quirk_printer_struct quirk_printers[] = {
213         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
214         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
215         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
216         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
217         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
218         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
219         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */   
220         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */   
221         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
222         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
223         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
224         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
225         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
226         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
227         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
228         { 0, 0 }
229 };
230
231 static int usblp_wwait(struct usblp *usblp, int nonblock);
232 static int usblp_wtest(struct usblp *usblp, int nonblock);
233 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
234 static int usblp_rtest(struct usblp *usblp, int nonblock);
235 static int usblp_submit_read(struct usblp *usblp);
236 static int usblp_select_alts(struct usblp *usblp);
237 static int usblp_set_protocol(struct usblp *usblp, int protocol);
238 static int usblp_cache_device_id_string(struct usblp *usblp);
239
240 /* forward reference to make our lives easier */
241 static struct usb_driver usblp_driver;
242 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
243
244 /*
245  * Functions for usblp control messages.
246  */
247
248 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
249 {
250         int retval;
251         int index = usblp->ifnum;
252
253         /* High byte has the interface index.
254            Low byte has the alternate setting.
255          */
256         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
257           index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
258         }
259
260         retval = usb_control_msg(usblp->dev,
261                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
262                 request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
263         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
264                 request, !!dir, recip, value, index, len, retval);
265         return retval < 0 ? retval : 0;
266 }
267
268 #define usblp_read_status(usblp, status)\
269         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
270 #define usblp_get_id(usblp, config, id, maxlen)\
271         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
272 #define usblp_reset(usblp)\
273         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
274
275 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
276         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
277
278 /*
279  * See the description for usblp_select_alts() below for the usage
280  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
281  * case of any trouble.
282  */
283 static int proto_bias = -1;
284
285 /*
286  * URB callback.
287  */
288
289 static void usblp_bulk_read(struct urb *urb)
290 {
291         struct usblp *usblp = urb->context;
292
293         if (usblp->present && usblp->used) {
294                 if (urb->status)
295                         printk(KERN_WARNING "usblp%d: "
296                             "nonzero read bulk status received: %d\n",
297                             usblp->minor, urb->status);
298         }
299         spin_lock(&usblp->lock);
300         if (urb->status < 0)
301                 usblp->rstatus = urb->status;
302         else
303                 usblp->rstatus = urb->actual_length;
304         usblp->rcomplete = 1;
305         wake_up(&usblp->rwait);
306         spin_unlock(&usblp->lock);
307
308         usb_free_urb(urb);
309 }
310
311 static void usblp_bulk_write(struct urb *urb)
312 {
313         struct usblp *usblp = urb->context;
314
315         if (usblp->present && usblp->used) {
316                 if (urb->status)
317                         printk(KERN_WARNING "usblp%d: "
318                             "nonzero write bulk status received: %d\n",
319                             usblp->minor, urb->status);
320         }
321         spin_lock(&usblp->lock);
322         if (urb->status < 0)
323                 usblp->wstatus = urb->status;
324         else
325                 usblp->wstatus = urb->actual_length;
326         usblp->wcomplete = 1;
327         wake_up(&usblp->wwait);
328         spin_unlock(&usblp->lock);
329
330         /* XXX Use usb_setup_bulk_urb when available. Talk to Marcel. */
331         kfree(urb->transfer_buffer);
332         urb->transfer_buffer = NULL;    /* Not refcounted, so to be safe... */
333         usb_free_urb(urb);
334 }
335
336 /*
337  * Get and print printer errors.
338  */
339
340 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
341
342 static int usblp_check_status(struct usblp *usblp, int err)
343 {
344         unsigned char status, newerr = 0;
345         int error;
346
347         error = usblp_read_status (usblp, usblp->statusbuf);
348         if (error < 0) {
349                 if (printk_ratelimit())
350                         printk(KERN_ERR
351                                 "usblp%d: error %d reading printer status\n",
352                                 usblp->minor, error);
353                 return 0;
354         }
355
356         status = *usblp->statusbuf;
357
358         if (~status & LP_PERRORP)
359                 newerr = 3;
360         if (status & LP_POUTPA)
361                 newerr = 1;
362         if (~status & LP_PSELECD)
363                 newerr = 2;
364
365         if (newerr != err) {
366                 printk(KERN_INFO "usblp%d: %s\n",
367                    usblp->minor, usblp_messages[newerr]);
368         }
369
370         return newerr;
371 }
372
373 static int handle_bidir (struct usblp *usblp)
374 {
375         if (usblp->bidir && usblp->used && !usblp->sleeping) {
376                 if (usblp_submit_read(usblp) < 0)
377                         return -EIO;
378         }
379         return 0;
380 }
381
382 /*
383  * File op functions.
384  */
385
386 static int usblp_open(struct inode *inode, struct file *file)
387 {
388         int minor = iminor(inode);
389         struct usblp *usblp;
390         struct usb_interface *intf;
391         int retval;
392
393         if (minor < 0)
394                 return -ENODEV;
395
396         mutex_lock (&usblp_mutex);
397
398         retval = -ENODEV;
399         intf = usb_find_interface(&usblp_driver, minor);
400         if (!intf) {
401                 goto out;
402         }
403         usblp = usb_get_intfdata (intf);
404         if (!usblp || !usblp->dev || !usblp->present)
405                 goto out;
406
407         retval = -EBUSY;
408         if (usblp->used)
409                 goto out;
410
411         /*
412          * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
413          * This is #if 0-ed because we *don't* want to fail an open
414          * just because the printer is off-line.
415          */
416 #if 0
417         if ((retval = usblp_check_status(usblp, 0))) {
418                 retval = retval > 1 ? -EIO : -ENOSPC;
419                 goto out;
420         }
421 #else
422         retval = 0;
423 #endif
424
425         retval = usb_autopm_get_interface(intf);
426         if (retval < 0)
427                 goto out;
428         usblp->used = 1;
429         file->private_data = usblp;
430
431         usblp->wcomplete = 1; /* we begin writeable */
432         usblp->wstatus = 0;
433         usblp->rcomplete = 0;
434
435         if (handle_bidir(usblp) < 0) {
436                 usblp->used = 0;
437                 file->private_data = NULL;
438                 retval = -EIO;
439         }
440 out:
441         mutex_unlock (&usblp_mutex);
442         return retval;
443 }
444
445 static void usblp_cleanup (struct usblp *usblp)
446 {
447         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
448
449         kfree(usblp->readbuf);
450         kfree (usblp->device_id_string);
451         kfree (usblp->statusbuf);
452         kfree (usblp);
453 }
454
455 static void usblp_unlink_urbs(struct usblp *usblp)
456 {
457         usb_kill_anchored_urbs(&usblp->urbs);
458 }
459
460 static int usblp_release(struct inode *inode, struct file *file)
461 {
462         struct usblp *usblp = file->private_data;
463
464         mutex_lock (&usblp_mutex);
465         usblp->used = 0;
466         if (usblp->present) {
467                 usblp_unlink_urbs(usblp);
468                 usb_autopm_put_interface(usblp->intf);
469         } else          /* finish cleanup from disconnect */
470                 usblp_cleanup (usblp);
471         mutex_unlock (&usblp_mutex);
472         return 0;
473 }
474
475 /* No kernel lock - fine */
476 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
477 {
478         int ret;
479         unsigned long flags;
480
481         struct usblp *usblp = file->private_data;
482         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
483         poll_wait(file, &usblp->rwait, wait);
484         poll_wait(file, &usblp->wwait, wait);
485         spin_lock_irqsave(&usblp->lock, flags);
486         ret = ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
487                                | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
488         spin_unlock_irqrestore(&usblp->lock, flags);
489         return ret;
490 }
491
492 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
493 {
494         struct usblp *usblp = file->private_data;
495         int length, err, i;
496         unsigned char newChannel;
497         int status;
498         int twoints[2];
499         int retval = 0;
500
501         mutex_lock (&usblp->mut);
502         if (!usblp->present) {
503                 retval = -ENODEV;
504                 goto done;
505         }
506
507         if (usblp->sleeping) {
508                 retval = -ENODEV;
509                 goto done;
510         }
511
512         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
513                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
514
515         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
516
517                 switch (_IOC_NR(cmd)) {
518
519                         case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
520                                 if (_IOC_DIR(cmd) != _IOC_READ) {
521                                         retval = -EINVAL;
522                                         goto done;
523                                 }
524
525                                 length = usblp_cache_device_id_string(usblp);
526                                 if (length < 0) {
527                                         retval = length;
528                                         goto done;
529                                 }
530                                 if (length > _IOC_SIZE(cmd))
531                                         length = _IOC_SIZE(cmd); /* truncate */
532
533                                 if (copy_to_user((void __user *) arg,
534                                                 usblp->device_id_string,
535                                                 (unsigned long) length)) {
536                                         retval = -EFAULT;
537                                         goto done;
538                                 }
539
540                                 break;
541
542                         case IOCNR_GET_PROTOCOLS:
543                                 if (_IOC_DIR(cmd) != _IOC_READ ||
544                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
545                                         retval = -EINVAL;
546                                         goto done;
547                                 }
548
549                                 twoints[0] = usblp->current_protocol;
550                                 twoints[1] = 0;
551                                 for (i = USBLP_FIRST_PROTOCOL;
552                                      i <= USBLP_LAST_PROTOCOL; i++) {
553                                         if (usblp->protocol[i].alt_setting >= 0)
554                                                 twoints[1] |= (1<<i);
555                                 }
556
557                                 if (copy_to_user((void __user *)arg,
558                                                 (unsigned char *)twoints,
559                                                 sizeof(twoints))) {
560                                         retval = -EFAULT;
561                                         goto done;
562                                 }
563
564                                 break;
565
566                         case IOCNR_SET_PROTOCOL:
567                                 if (_IOC_DIR(cmd) != _IOC_WRITE) {
568                                         retval = -EINVAL;
569                                         goto done;
570                                 }
571
572 #ifdef DEBUG
573                                 if (arg == -10) {
574                                         usblp_dump(usblp);
575                                         break;
576                                 }
577 #endif
578
579                                 usblp_unlink_urbs(usblp);
580                                 retval = usblp_set_protocol(usblp, arg);
581                                 if (retval < 0) {
582                                         usblp_set_protocol(usblp,
583                                                 usblp->current_protocol);
584                                 }
585                                 break;
586
587                         case IOCNR_HP_SET_CHANNEL:
588                                 if (_IOC_DIR(cmd) != _IOC_WRITE ||
589                                     le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
590                                     usblp->quirks & USBLP_QUIRK_BIDIR) {
591                                         retval = -EINVAL;
592                                         goto done;
593                                 }
594
595                                 err = usblp_hp_channel_change_request(usblp,
596                                         arg, &newChannel);
597                                 if (err < 0) {
598                                         err("usblp%d: error = %d setting "
599                                                 "HP channel",
600                                                 usblp->minor, err);
601                                         retval = -EIO;
602                                         goto done;
603                                 }
604
605                                 dbg("usblp%d requested/got HP channel %ld/%d",
606                                         usblp->minor, arg, newChannel);
607                                 break;
608
609                         case IOCNR_GET_BUS_ADDRESS:
610                                 if (_IOC_DIR(cmd) != _IOC_READ ||
611                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
612                                         retval = -EINVAL;
613                                         goto done;
614                                 }
615
616                                 twoints[0] = usblp->dev->bus->busnum;
617                                 twoints[1] = usblp->dev->devnum;
618                                 if (copy_to_user((void __user *)arg,
619                                                 (unsigned char *)twoints,
620                                                 sizeof(twoints))) {
621                                         retval = -EFAULT;
622                                         goto done;
623                                 }
624
625                                 dbg("usblp%d is bus=%d, device=%d",
626                                         usblp->minor, twoints[0], twoints[1]);
627                                 break;
628
629                         case IOCNR_GET_VID_PID:
630                                 if (_IOC_DIR(cmd) != _IOC_READ ||
631                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
632                                         retval = -EINVAL;
633                                         goto done;
634                                 }
635
636                                 twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
637                                 twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
638                                 if (copy_to_user((void __user *)arg,
639                                                 (unsigned char *)twoints,
640                                                 sizeof(twoints))) {
641                                         retval = -EFAULT;
642                                         goto done;
643                                 }
644
645                                 dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
646                                         usblp->minor, twoints[0], twoints[1]);
647                                 break;
648
649                         case IOCNR_SOFT_RESET:
650                                 if (_IOC_DIR(cmd) != _IOC_NONE) {
651                                         retval = -EINVAL;
652                                         goto done;
653                                 }
654                                 retval = usblp_reset(usblp);
655                                 break;
656                         default:
657                                 retval = -ENOTTY;
658                 }
659         else    /* old-style ioctl value */
660                 switch (cmd) {
661
662                         case LPGETSTATUS:
663                                 if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
664                                         if (printk_ratelimit())
665                                                 printk(KERN_ERR "usblp%d:"
666                                                     "failed reading printer status (%d)\n",
667                                                     usblp->minor, retval);
668                                         retval = -EIO;
669                                         goto done;
670                                 }
671                                 status = *usblp->statusbuf;
672                                 if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
673                                         retval = -EFAULT;
674                                 break;
675
676                         default:
677                                 retval = -ENOTTY;
678                 }
679
680 done:
681         mutex_unlock (&usblp->mut);
682         return retval;
683 }
684
685 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
686 {
687         struct usblp *usblp = file->private_data;
688         char *writebuf;
689         struct urb *writeurb;
690         int rv;
691         int transfer_length;
692         ssize_t writecount = 0;
693
694         if (mutex_lock_interruptible(&usblp->wmut)) {
695                 rv = -EINTR;
696                 goto raise_biglock;
697         }
698         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
699                 goto raise_wait;
700
701         while (writecount < count) {
702                 /*
703                  * Step 1: Submit next block.
704                  */
705                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
706                         transfer_length = USBLP_BUF_SIZE;
707
708                 rv = -ENOMEM;
709                 if ((writebuf = kmalloc(USBLP_BUF_SIZE, GFP_KERNEL)) == NULL)
710                         goto raise_buf;
711                 if ((writeurb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
712                         goto raise_urb;
713                 usb_fill_bulk_urb(writeurb, usblp->dev,
714                         usb_sndbulkpipe(usblp->dev,
715                           usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
716                         writebuf, transfer_length, usblp_bulk_write, usblp);
717                 usb_anchor_urb(writeurb, &usblp->urbs);
718
719                 if (copy_from_user(writebuf,
720                                    buffer + writecount, transfer_length)) {
721                         rv = -EFAULT;
722                         goto raise_badaddr;
723                 }
724
725                 spin_lock_irq(&usblp->lock);
726                 usblp->wcomplete = 0;
727                 spin_unlock_irq(&usblp->lock);
728                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
729                         usblp->wstatus = 0;
730                         spin_lock_irq(&usblp->lock);
731                         usblp->wcomplete = 1;
732                         wake_up(&usblp->wwait);
733                         spin_unlock_irq(&usblp->lock);
734                         if (rv != -ENOMEM)
735                                 rv = -EIO;
736                         goto raise_submit;
737                 }
738
739                 /*
740                  * Step 2: Wait for transfer to end, collect results.
741                  */
742                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
743                 if (rv < 0) {
744                         /*
745                          * If interrupted, we simply leave the URB to dangle,
746                          * so the ->release will call usb_kill_urb().
747                          */
748                         goto collect_error;
749                 }
750
751                 if (usblp->wstatus < 0) {
752                         usblp_check_status(usblp, 0);
753                         rv = -EIO;
754                         goto collect_error;
755                 }
756                 /*
757                  * This is critical: it must be our URB, not other writer's.
758                  * The wmut exists mainly to cover us here.
759                  */
760                 writecount += usblp->wstatus;
761         }
762
763         mutex_unlock(&usblp->wmut);
764         return writecount;
765
766 raise_submit:
767 raise_badaddr:
768         usb_unanchor_urb(writeurb);
769         usb_free_urb(writeurb);
770 raise_urb:
771         kfree(writebuf);
772 raise_buf:
773 raise_wait:
774 collect_error:          /* Out of raise sequence */
775         mutex_unlock(&usblp->wmut);
776 raise_biglock:
777         return writecount ? writecount : rv;
778 }
779
780 /*
781  * Notice that we fail to restart in a few cases: on EFAULT, on restart
782  * error, etc. This is the historical behaviour. In all such cases we return
783  * EIO, and applications loop in order to get the new read going.
784  */
785 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
786 {
787         struct usblp *usblp = file->private_data;
788         ssize_t count;
789         ssize_t avail;
790         int rv;
791
792         if (!usblp->bidir)
793                 return -EINVAL;
794
795         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
796         if (rv < 0)
797                 return rv;
798
799         if ((avail = usblp->rstatus) < 0) {
800                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
801                     usblp->minor, (int)avail);
802                 usblp_submit_read(usblp);
803                 count = -EIO;
804                 goto done;
805         }
806
807         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
808         if (count != 0 &&
809             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
810                 count = -EFAULT;
811                 goto done;
812         }
813
814         if ((usblp->readcount += count) == avail) {
815                 if (usblp_submit_read(usblp) < 0) {
816                         /* We don't want to leak USB return codes into errno. */
817                         if (count == 0)
818                                 count = -EIO;
819                         goto done;
820                 }
821         }
822
823 done:
824         mutex_unlock (&usblp->mut);
825         return count;
826 }
827
828 /*
829  * Wait for the write path to come idle.
830  * This is called under the ->wmut, so the idle path stays idle.
831  *
832  * Our write path has a peculiar property: it does not buffer like a tty,
833  * but waits for the write to succeed. This allows our ->release to bug out
834  * without waiting for writes to drain. But it obviously does not work
835  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
836  * select(2) or poll(2) to wait for the buffer to drain before closing.
837  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
838  *
839  * Old v0.13 code had a non-functional timeout for wait_event(). Someone forgot
840  * to check the return code for timeout expiration, so it had no effect.
841  * Apparently, it was intended to check for error conditons, such as out
842  * of paper. It is going to return when we settle things with CUPS. XXX
843  */
844 static int usblp_wwait(struct usblp *usblp, int nonblock)
845 {
846         DECLARE_WAITQUEUE(waita, current);
847         int rc;
848
849         add_wait_queue(&usblp->wwait, &waita);
850         for (;;) {
851                 if (mutex_lock_interruptible(&usblp->mut)) {
852                         rc = -EINTR;
853                         break;
854                 }
855                 set_current_state(TASK_INTERRUPTIBLE);
856                 if ((rc = usblp_wtest(usblp, nonblock)) < 0) {
857                         mutex_unlock(&usblp->mut);
858                         break;
859                 }
860                 mutex_unlock(&usblp->mut);
861                 if (rc == 0)
862                         break;
863                 schedule();
864         }
865         set_current_state(TASK_RUNNING);
866         remove_wait_queue(&usblp->wwait, &waita);
867         return rc;
868 }
869
870 static int usblp_wtest(struct usblp *usblp, int nonblock)
871 {
872         unsigned long flags;
873
874         if (!usblp->present)
875                 return -ENODEV;
876         if (signal_pending(current))
877                 return -EINTR;
878         spin_lock_irqsave(&usblp->lock, flags);
879         if (usblp->wcomplete) {
880                 spin_unlock_irqrestore(&usblp->lock, flags);
881                 return 0;
882         }
883         spin_unlock_irqrestore(&usblp->lock, flags);
884         if (usblp->sleeping)
885                 return -ENODEV;
886         if (nonblock)
887                 return -EAGAIN;
888         return 1;
889 }
890
891 /*
892  * Wait for read bytes to become available. This probably should have been
893  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
894  * name for functions which lock and return.
895  *
896  * We do not use wait_event_interruptible because it makes locking iffy.
897  */
898 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
899 {
900         DECLARE_WAITQUEUE(waita, current);
901         int rc;
902
903         add_wait_queue(&usblp->rwait, &waita);
904         for (;;) {
905                 if (mutex_lock_interruptible(&usblp->mut)) {
906                         rc = -EINTR;
907                         break;
908                 }
909                 set_current_state(TASK_INTERRUPTIBLE);
910                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
911                         mutex_unlock(&usblp->mut);
912                         break;
913                 }
914                 if (rc == 0)    /* Keep it locked */
915                         break;
916                 mutex_unlock(&usblp->mut);
917                 schedule();
918         }
919         set_current_state(TASK_RUNNING);
920         remove_wait_queue(&usblp->rwait, &waita);
921         return rc;
922 }
923
924 static int usblp_rtest(struct usblp *usblp, int nonblock)
925 {
926         unsigned long flags;
927
928         if (!usblp->present)
929                 return -ENODEV;
930         if (signal_pending(current))
931                 return -EINTR;
932         spin_lock_irqsave(&usblp->lock, flags);
933         if (usblp->rcomplete) {
934                 spin_unlock_irqrestore(&usblp->lock, flags);
935                 return 0;
936         }
937         spin_unlock_irqrestore(&usblp->lock, flags);
938         if (usblp->sleeping)
939                 return -ENODEV;
940         if (nonblock)
941                 return -EAGAIN;
942         return 1;
943 }
944
945 /*
946  * Please check ->bidir and other such things outside for now.
947  */
948 static int usblp_submit_read(struct usblp *usblp)
949 {
950         struct urb *urb;
951         unsigned long flags;
952         int rc;
953
954         rc = -ENOMEM;
955         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
956                 goto raise_urb;
957
958         usb_fill_bulk_urb(urb, usblp->dev,
959                 usb_rcvbulkpipe(usblp->dev,
960                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
961                 usblp->readbuf, USBLP_BUF_SIZE_IN,
962                 usblp_bulk_read, usblp);
963         usb_anchor_urb(urb, &usblp->urbs);
964
965         spin_lock_irqsave(&usblp->lock, flags);
966         usblp->readcount = 0; /* XXX Why here? */
967         usblp->rcomplete = 0;
968         spin_unlock_irqrestore(&usblp->lock, flags);
969         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
970                 dbg("error submitting urb (%d)", rc);
971                 spin_lock_irqsave(&usblp->lock, flags);
972                 usblp->rstatus = rc;
973                 usblp->rcomplete = 1;
974                 spin_unlock_irqrestore(&usblp->lock, flags);
975                 goto raise_submit;
976         }
977
978         return 0;
979
980 raise_submit:
981         usb_unanchor_urb(urb);
982         usb_free_urb(urb);
983 raise_urb:
984         return rc;
985 }
986
987 /*
988  * Checks for printers that have quirks, such as requiring unidirectional
989  * communication but reporting bidirectional; currently some HP printers
990  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
991  * sent at each open (like some Epsons).
992  * Returns 1 if found, 0 if not found.
993  *
994  * HP recommended that we use the bidirectional interface but
995  * don't attempt any bulk IN transfers from the IN endpoint.
996  * Here's some more detail on the problem:
997  * The problem is not that it isn't bidirectional though. The problem
998  * is that if you request a device ID, or status information, while
999  * the buffers are full, the return data will end up in the print data
1000  * buffer. For example if you make sure you never request the device ID
1001  * while you are sending print data, and you don't try to query the
1002  * printer status every couple of milliseconds, you will probably be OK.
1003  */
1004 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
1005 {
1006         int i;
1007
1008         for (i = 0; quirk_printers[i].vendorId; i++) {
1009                 if (vendor == quirk_printers[i].vendorId &&
1010                     product == quirk_printers[i].productId)
1011                         return quirk_printers[i].quirks;
1012         }
1013         return 0;
1014 }
1015
1016 static const struct file_operations usblp_fops = {
1017         .owner =        THIS_MODULE,
1018         .read =         usblp_read,
1019         .write =        usblp_write,
1020         .poll =         usblp_poll,
1021         .unlocked_ioctl =       usblp_ioctl,
1022         .compat_ioctl =         usblp_ioctl,
1023         .open =         usblp_open,
1024         .release =      usblp_release,
1025 };
1026
1027 static struct usb_class_driver usblp_class = {
1028         .name =         "lp%d",
1029         .fops =         &usblp_fops,
1030         .minor_base =   USBLP_MINOR_BASE,
1031 };
1032
1033 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1034 {
1035         struct usb_interface *intf = to_usb_interface(dev);
1036         struct usblp *usblp = usb_get_intfdata (intf);
1037
1038         if (usblp->device_id_string[0] == 0 &&
1039             usblp->device_id_string[1] == 0)
1040                 return 0;
1041
1042         return sprintf(buf, "%s", usblp->device_id_string+2);
1043 }
1044
1045 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1046
1047 static int usblp_probe(struct usb_interface *intf,
1048                        const struct usb_device_id *id)
1049 {
1050         struct usb_device *dev = interface_to_usbdev (intf);
1051         struct usblp *usblp = NULL;
1052         int protocol;
1053         int retval;
1054
1055         /* Malloc and start initializing usblp structure so we can use it
1056          * directly. */
1057         if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
1058                 retval = -ENOMEM;
1059                 goto abort;
1060         }
1061         usblp->dev = dev;
1062         mutex_init(&usblp->wmut);
1063         mutex_init (&usblp->mut);
1064         spin_lock_init(&usblp->lock);
1065         init_waitqueue_head(&usblp->rwait);
1066         init_waitqueue_head(&usblp->wwait);
1067         init_usb_anchor(&usblp->urbs);
1068         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1069         usblp->intf = intf;
1070
1071         /* Malloc device ID string buffer to the largest expected length,
1072          * since we can re-query it on an ioctl and a dynamic string
1073          * could change in length. */
1074         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1075                 retval = -ENOMEM;
1076                 goto abort;
1077         }
1078
1079         /*
1080          * Allocate read buffer. We somewhat wastefully
1081          * malloc both regardless of bidirectionality, because the
1082          * alternate setting can be changed later via an ioctl.
1083          */
1084         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1085                 retval = -ENOMEM;
1086                 goto abort;
1087         }
1088
1089         /* Allocate buffer for printer status */
1090         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1091         if (!usblp->statusbuf) {
1092                 retval = -ENOMEM;
1093                 goto abort;
1094         }
1095
1096         /* Lookup quirks for this printer. */
1097         usblp->quirks = usblp_quirks(
1098                 le16_to_cpu(dev->descriptor.idVendor),
1099                 le16_to_cpu(dev->descriptor.idProduct));
1100
1101         /* Analyze and pick initial alternate settings and endpoints. */
1102         protocol = usblp_select_alts(usblp);
1103         if (protocol < 0) {
1104                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1105                         le16_to_cpu(dev->descriptor.idVendor),
1106                         le16_to_cpu(dev->descriptor.idProduct));
1107                 retval = -ENODEV;
1108                 goto abort;
1109         }
1110
1111         /* Setup the selected alternate setting and endpoints. */
1112         if (usblp_set_protocol(usblp, protocol) < 0) {
1113                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1114                 goto abort;
1115         }
1116
1117         /* Retrieve and store the device ID string. */
1118         usblp_cache_device_id_string(usblp);
1119         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1120         if (retval)
1121                 goto abort_intfdata;
1122
1123 #ifdef DEBUG
1124         usblp_check_status(usblp, 0);
1125 #endif
1126
1127         usb_set_intfdata (intf, usblp);
1128
1129         usblp->present = 1;
1130
1131         retval = usb_register_dev(intf, &usblp_class);
1132         if (retval) {
1133                 printk(KERN_ERR "usblp: Not able to get a minor"
1134                     " (base %u, slice default): %d\n",
1135                     USBLP_MINOR_BASE, retval);
1136                 goto abort_intfdata;
1137         }
1138         usblp->minor = intf->minor;
1139         printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1140                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1141                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1142                 usblp->ifnum,
1143                 usblp->protocol[usblp->current_protocol].alt_setting,
1144                 usblp->current_protocol,
1145                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1146                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1147
1148         return 0;
1149
1150 abort_intfdata:
1151         usb_set_intfdata (intf, NULL);
1152         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1153 abort:
1154         if (usblp) {
1155                 kfree(usblp->readbuf);
1156                 kfree(usblp->statusbuf);
1157                 kfree(usblp->device_id_string);
1158                 kfree(usblp);
1159         }
1160         return retval;
1161 }
1162
1163 /*
1164  * We are a "new" style driver with usb_device_id table,
1165  * but our requirements are too intricate for simple match to handle.
1166  *
1167  * The "proto_bias" option may be used to specify the preferred protocol
1168  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1169  * supports the preferred protocol, then we bind to it.
1170  *
1171  * The best interface for us is 7/1/2, because it is compatible
1172  * with a stream of characters. If we find it, we bind to it.
1173  *
1174  * Note that the people from hpoj.sourceforge.net need to be able to
1175  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1176  *
1177  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1178  * stream-compatible, because this matches the behaviour of the old code.
1179  *
1180  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1181  */
1182 static int usblp_select_alts(struct usblp *usblp)
1183 {
1184         struct usb_interface *if_alt;
1185         struct usb_host_interface *ifd;
1186         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1187         int p, i, e;
1188
1189         if_alt = usblp->intf;
1190
1191         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1192                 usblp->protocol[p].alt_setting = -1;
1193
1194         /* Find out what we have. */
1195         for (i = 0; i < if_alt->num_altsetting; i++) {
1196                 ifd = &if_alt->altsetting[i];
1197
1198                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1199                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1200                                 continue;
1201
1202                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1203                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1204                         continue;
1205
1206                 /* Look for bulk OUT and IN endpoints. */
1207                 epwrite = epread = NULL;
1208                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1209                         epd = &ifd->endpoint[e].desc;
1210
1211                         if (usb_endpoint_is_bulk_out(epd))
1212                                 if (!epwrite)
1213                                         epwrite = epd;
1214
1215                         if (usb_endpoint_is_bulk_in(epd))
1216                                 if (!epread)
1217                                         epread = epd;
1218                 }
1219
1220                 /* Ignore buggy hardware without the right endpoints. */
1221                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1222                         continue;
1223
1224                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1225                  * and buggy bidirectional printers. */
1226                 if (ifd->desc.bInterfaceProtocol == 1) {
1227                         epread = NULL;
1228                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1229                         printk(KERN_INFO "usblp%d: Disabling reads from "
1230                             "problematic bidirectional printer\n",
1231                             usblp->minor);
1232                         epread = NULL;
1233                 }
1234
1235                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1236                                 ifd->desc.bAlternateSetting;
1237                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1238                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1239         }
1240
1241         /* If our requested protocol is supported, then use it. */
1242         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1243             proto_bias <= USBLP_LAST_PROTOCOL &&
1244             usblp->protocol[proto_bias].alt_setting != -1)
1245                 return proto_bias;
1246
1247         /* Ordering is important here. */
1248         if (usblp->protocol[2].alt_setting != -1)
1249                 return 2;
1250         if (usblp->protocol[1].alt_setting != -1)
1251                 return 1;
1252         if (usblp->protocol[3].alt_setting != -1)
1253                 return 3;
1254
1255         /* If nothing is available, then don't bind to this device. */
1256         return -1;
1257 }
1258
1259 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1260 {
1261         int r, alts;
1262
1263         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1264                 return -EINVAL;
1265
1266         alts = usblp->protocol[protocol].alt_setting;
1267         if (alts < 0)
1268                 return -EINVAL;
1269         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1270         if (r < 0) {
1271                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1272                         alts, usblp->ifnum);
1273                 return r;
1274         }
1275
1276         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1277         usblp->current_protocol = protocol;
1278         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1279         return 0;
1280 }
1281
1282 /* Retrieves and caches device ID string.
1283  * Returns length, including length bytes but not null terminator.
1284  * On error, returns a negative errno value. */
1285 static int usblp_cache_device_id_string(struct usblp *usblp)
1286 {
1287         int err, length;
1288
1289         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1290         if (err < 0) {
1291                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1292                         usblp->minor, err);
1293                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1294                 return -EIO;
1295         }
1296
1297         /* First two bytes are length in big-endian.
1298          * They count themselves, and we copy them into
1299          * the user's buffer. */
1300         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1301         if (length < 2)
1302                 length = 2;
1303         else if (length >= USBLP_DEVICE_ID_SIZE)
1304                 length = USBLP_DEVICE_ID_SIZE - 1;
1305         usblp->device_id_string[length] = '\0';
1306
1307         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1308                 usblp->minor, length, &usblp->device_id_string[2]);
1309
1310         return length;
1311 }
1312
1313 static void usblp_disconnect(struct usb_interface *intf)
1314 {
1315         struct usblp *usblp = usb_get_intfdata (intf);
1316
1317         usb_deregister_dev(intf, &usblp_class);
1318
1319         if (!usblp || !usblp->dev) {
1320                 err("bogus disconnect");
1321                 BUG ();
1322         }
1323
1324         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1325
1326         mutex_lock (&usblp_mutex);
1327         mutex_lock (&usblp->mut);
1328         usblp->present = 0;
1329         wake_up(&usblp->wwait);
1330         wake_up(&usblp->rwait);
1331         usb_set_intfdata (intf, NULL);
1332
1333         usblp_unlink_urbs(usblp);
1334         mutex_unlock (&usblp->mut);
1335
1336         if (!usblp->used)
1337                 usblp_cleanup (usblp);
1338         mutex_unlock (&usblp_mutex);
1339 }
1340
1341 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1342 {
1343         struct usblp *usblp = usb_get_intfdata (intf);
1344
1345         /* we take no more IO */
1346         usblp->sleeping = 1;
1347         usblp_unlink_urbs(usblp);
1348 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1349         /* not strictly necessary, but just in case */
1350         wake_up(&usblp->wwait);
1351         wake_up(&usblp->rwait);
1352 #endif
1353
1354         return 0;
1355 }
1356
1357 static int usblp_resume (struct usb_interface *intf)
1358 {
1359         struct usblp *usblp = usb_get_intfdata (intf);
1360         int r;
1361
1362         usblp->sleeping = 0;
1363         r = handle_bidir (usblp);
1364
1365         return r;
1366 }
1367
1368 static struct usb_device_id usblp_ids [] = {
1369         { USB_DEVICE_INFO(7, 1, 1) },
1370         { USB_DEVICE_INFO(7, 1, 2) },
1371         { USB_DEVICE_INFO(7, 1, 3) },
1372         { USB_INTERFACE_INFO(7, 1, 1) },
1373         { USB_INTERFACE_INFO(7, 1, 2) },
1374         { USB_INTERFACE_INFO(7, 1, 3) },
1375         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1376         { }                                             /* Terminating entry */
1377 };
1378
1379 MODULE_DEVICE_TABLE (usb, usblp_ids);
1380
1381 static struct usb_driver usblp_driver = {
1382         .name =         "usblp",
1383         .probe =        usblp_probe,
1384         .disconnect =   usblp_disconnect,
1385         .suspend =      usblp_suspend,
1386         .resume =       usblp_resume,
1387         .id_table =     usblp_ids,
1388         .supports_autosuspend = 1,
1389 };
1390
1391 static int __init usblp_init(void)
1392 {
1393         return usb_register(&usblp_driver);
1394 }
1395
1396 static void __exit usblp_exit(void)
1397 {
1398         usb_deregister(&usblp_driver);
1399 }
1400
1401 module_init(usblp_init);
1402 module_exit(usblp_exit);
1403
1404 MODULE_AUTHOR( DRIVER_AUTHOR );
1405 MODULE_DESCRIPTION( DRIVER_DESC );
1406 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1407 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1408 MODULE_LICENSE("GPL");