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drivers/usb/class/usblp.c: adjust error handling code
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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  *      none  - Maintained in Linux kernel after v0.13
32  */
33
34 /*
35  * This program is free software; you can redistribute it and/or modify
36  * it under the terms of the GNU General Public License as published by
37  * the Free Software Foundation; either version 2 of the License, or
38  * (at your option) any later version.
39  *
40  * This program is distributed in the hope that it will be useful,
41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
43  * GNU General Public License for more details.
44  *
45  * You should have received a copy of the GNU General Public License
46  * along with this program; if not, write to the Free Software
47  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
48  */
49
50 #include <linux/module.h>
51 #include <linux/kernel.h>
52 #include <linux/sched.h>
53 #include <linux/signal.h>
54 #include <linux/poll.h>
55 #include <linux/init.h>
56 #include <linux/slab.h>
57 #include <linux/lp.h>
58 #include <linux/mutex.h>
59 #undef DEBUG
60 #include <linux/usb.h>
61
62 /*
63  * Version Information
64  */
65 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
66 #define DRIVER_DESC "USB Printer Device Class driver"
67
68 #define USBLP_BUF_SIZE          8192
69 #define USBLP_BUF_SIZE_IN       1024
70 #define USBLP_DEVICE_ID_SIZE    1024
71
72 /* ioctls: */
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_CTL_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 int            flags;                  /* mode flags */
163         unsigned char           used;                   /* True if open */
164         unsigned char           present;                /* True if not disconnected */
165         unsigned char           bidir;                  /* interface is bidirectional */
166         unsigned char           sleeping;               /* interface is suspended */
167         unsigned char           no_paper;               /* Paper Out happened */
168         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
169                                                         /* first 2 bytes are (big-endian) length */
170 };
171
172 #ifdef DEBUG
173 static void usblp_dump(struct usblp *usblp) {
174         int p;
175
176         dbg("usblp=0x%p", usblp);
177         dbg("dev=0x%p", usblp->dev);
178         dbg("present=%d", usblp->present);
179         dbg("readbuf=0x%p", usblp->readbuf);
180         dbg("readcount=%d", usblp->readcount);
181         dbg("ifnum=%d", usblp->ifnum);
182     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
183         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
184         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
185         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
186     }
187         dbg("current_protocol=%d", usblp->current_protocol);
188         dbg("minor=%d", usblp->minor);
189         dbg("wstatus=%d", usblp->wstatus);
190         dbg("rstatus=%d", usblp->rstatus);
191         dbg("quirks=%d", usblp->quirks);
192         dbg("used=%d", usblp->used);
193         dbg("bidir=%d", usblp->bidir);
194         dbg("sleeping=%d", usblp->sleeping);
195         dbg("device_id_string=\"%s\"",
196                 usblp->device_id_string ?
197                         usblp->device_id_string + 2 :
198                         (unsigned char *)"(null)");
199 }
200 #endif
201
202 /* Quirks: various printer quirks are handled by this table & its flags. */
203
204 struct quirk_printer_struct {
205         __u16 vendorId;
206         __u16 productId;
207         unsigned int quirks;
208 };
209
210 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
211 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
212 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
213
214 static const struct quirk_printer_struct quirk_printers[] = {
215         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
216         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
217         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
218         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
219         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
220         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
221         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */   
222         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */   
223         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
224         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
225         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
226         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
227         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
228         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
229         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
230         { 0, 0 }
231 };
232
233 static int usblp_wwait(struct usblp *usblp, int nonblock);
234 static int usblp_wtest(struct usblp *usblp, int nonblock);
235 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
236 static int usblp_rtest(struct usblp *usblp, int nonblock);
237 static int usblp_submit_read(struct usblp *usblp);
238 static int usblp_select_alts(struct usblp *usblp);
239 static int usblp_set_protocol(struct usblp *usblp, int protocol);
240 static int usblp_cache_device_id_string(struct usblp *usblp);
241
242 /* forward reference to make our lives easier */
243 static struct usb_driver usblp_driver;
244 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
245
246 /*
247  * Functions for usblp control messages.
248  */
249
250 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
251 {
252         int retval;
253         int index = usblp->ifnum;
254
255         /* High byte has the interface index.
256            Low byte has the alternate setting.
257          */
258         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
259           index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
260         }
261
262         retval = usb_control_msg(usblp->dev,
263                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
264                 request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
265         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
266                 request, !!dir, recip, value, index, len, retval);
267         return retval < 0 ? retval : 0;
268 }
269
270 #define usblp_read_status(usblp, status)\
271         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
272 #define usblp_get_id(usblp, config, id, maxlen)\
273         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
274 #define usblp_reset(usblp)\
275         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
276
277 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
278         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
279
280 /*
281  * See the description for usblp_select_alts() below for the usage
282  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
283  * case of any trouble.
284  */
285 static int proto_bias = -1;
286
287 /*
288  * URB callback.
289  */
290
291 static void usblp_bulk_read(struct urb *urb)
292 {
293         struct usblp *usblp = urb->context;
294         int status = urb->status;
295
296         if (usblp->present && usblp->used) {
297                 if (status)
298                         printk(KERN_WARNING "usblp%d: "
299                             "nonzero read bulk status received: %d\n",
300                             usblp->minor, status);
301         }
302         spin_lock(&usblp->lock);
303         if (status < 0)
304                 usblp->rstatus = status;
305         else
306                 usblp->rstatus = urb->actual_length;
307         usblp->rcomplete = 1;
308         wake_up(&usblp->rwait);
309         spin_unlock(&usblp->lock);
310
311         usb_free_urb(urb);
312 }
313
314 static void usblp_bulk_write(struct urb *urb)
315 {
316         struct usblp *usblp = urb->context;
317         int status = urb->status;
318
319         if (usblp->present && usblp->used) {
320                 if (status)
321                         printk(KERN_WARNING "usblp%d: "
322                             "nonzero write bulk status received: %d\n",
323                             usblp->minor, status);
324         }
325         spin_lock(&usblp->lock);
326         if (status < 0)
327                 usblp->wstatus = status;
328         else
329                 usblp->wstatus = urb->actual_length;
330         usblp->no_paper = 0;
331         usblp->wcomplete = 1;
332         wake_up(&usblp->wwait);
333         spin_unlock(&usblp->lock);
334
335         usb_free_urb(urb);
336 }
337
338 /*
339  * Get and print printer errors.
340  */
341
342 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
343
344 static int usblp_check_status(struct usblp *usblp, int err)
345 {
346         unsigned char status, newerr = 0;
347         int error;
348
349         mutex_lock(&usblp->mut);
350         if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
351                 mutex_unlock(&usblp->mut);
352                 if (printk_ratelimit())
353                         printk(KERN_ERR
354                                 "usblp%d: error %d reading printer status\n",
355                                 usblp->minor, error);
356                 return 0;
357         }
358         status = *usblp->statusbuf;
359         mutex_unlock(&usblp->mut);
360
361         if (~status & LP_PERRORP)
362                 newerr = 3;
363         if (status & LP_POUTPA)
364                 newerr = 1;
365         if (~status & LP_PSELECD)
366                 newerr = 2;
367
368         if (newerr != err) {
369                 printk(KERN_INFO "usblp%d: %s\n",
370                    usblp->minor, usblp_messages[newerr]);
371         }
372
373         return newerr;
374 }
375
376 static int handle_bidir (struct usblp *usblp)
377 {
378         if (usblp->bidir && usblp->used && !usblp->sleeping) {
379                 if (usblp_submit_read(usblp) < 0)
380                         return -EIO;
381         }
382         return 0;
383 }
384
385 /*
386  * File op functions.
387  */
388
389 static int usblp_open(struct inode *inode, struct file *file)
390 {
391         int minor = iminor(inode);
392         struct usblp *usblp;
393         struct usb_interface *intf;
394         int retval;
395
396         if (minor < 0)
397                 return -ENODEV;
398
399         mutex_lock (&usblp_mutex);
400
401         retval = -ENODEV;
402         intf = usb_find_interface(&usblp_driver, minor);
403         if (!intf) {
404                 goto out;
405         }
406         usblp = usb_get_intfdata (intf);
407         if (!usblp || !usblp->dev || !usblp->present)
408                 goto out;
409
410         retval = -EBUSY;
411         if (usblp->used)
412                 goto out;
413
414         /*
415          * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
416          *  - We do not want persistent state which close(2) does not clear
417          *  - It is not used anyway, according to CUPS people
418          */
419
420         retval = usb_autopm_get_interface(intf);
421         if (retval < 0)
422                 goto out;
423         usblp->used = 1;
424         file->private_data = usblp;
425
426         usblp->wcomplete = 1; /* we begin writeable */
427         usblp->wstatus = 0;
428         usblp->rcomplete = 0;
429
430         if (handle_bidir(usblp) < 0) {
431                 usb_autopm_put_interface(intf);
432                 usblp->used = 0;
433                 file->private_data = NULL;
434                 retval = -EIO;
435         }
436 out:
437         mutex_unlock (&usblp_mutex);
438         return retval;
439 }
440
441 static void usblp_cleanup (struct usblp *usblp)
442 {
443         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
444
445         kfree(usblp->readbuf);
446         kfree (usblp->device_id_string);
447         kfree (usblp->statusbuf);
448         kfree (usblp);
449 }
450
451 static void usblp_unlink_urbs(struct usblp *usblp)
452 {
453         usb_kill_anchored_urbs(&usblp->urbs);
454 }
455
456 static int usblp_release(struct inode *inode, struct file *file)
457 {
458         struct usblp *usblp = file->private_data;
459
460         usblp->flags &= ~LP_ABORT;
461
462         mutex_lock (&usblp_mutex);
463         usblp->used = 0;
464         if (usblp->present) {
465                 usblp_unlink_urbs(usblp);
466                 usb_autopm_put_interface(usblp->intf);
467         } else          /* finish cleanup from disconnect */
468                 usblp_cleanup (usblp);
469         mutex_unlock (&usblp_mutex);
470         return 0;
471 }
472
473 /* No kernel lock - fine */
474 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
475 {
476         int ret;
477         unsigned long flags;
478
479         struct usblp *usblp = file->private_data;
480         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
481         poll_wait(file, &usblp->rwait, wait);
482         poll_wait(file, &usblp->wwait, wait);
483         spin_lock_irqsave(&usblp->lock, flags);
484         ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
485            ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
486         spin_unlock_irqrestore(&usblp->lock, flags);
487         return ret;
488 }
489
490 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
491 {
492         struct usblp *usblp = file->private_data;
493         int length, err, i;
494         unsigned char newChannel;
495         int status;
496         int twoints[2];
497         int retval = 0;
498
499         mutex_lock (&usblp->mut);
500         if (!usblp->present) {
501                 retval = -ENODEV;
502                 goto done;
503         }
504
505         if (usblp->sleeping) {
506                 retval = -ENODEV;
507                 goto done;
508         }
509
510         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
511                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
512
513         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
514
515                 switch (_IOC_NR(cmd)) {
516
517                         case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
518                                 if (_IOC_DIR(cmd) != _IOC_READ) {
519                                         retval = -EINVAL;
520                                         goto done;
521                                 }
522
523                                 length = usblp_cache_device_id_string(usblp);
524                                 if (length < 0) {
525                                         retval = length;
526                                         goto done;
527                                 }
528                                 if (length > _IOC_SIZE(cmd))
529                                         length = _IOC_SIZE(cmd); /* truncate */
530
531                                 if (copy_to_user((void __user *) arg,
532                                                 usblp->device_id_string,
533                                                 (unsigned long) length)) {
534                                         retval = -EFAULT;
535                                         goto done;
536                                 }
537
538                                 break;
539
540                         case IOCNR_GET_PROTOCOLS:
541                                 if (_IOC_DIR(cmd) != _IOC_READ ||
542                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
543                                         retval = -EINVAL;
544                                         goto done;
545                                 }
546
547                                 twoints[0] = usblp->current_protocol;
548                                 twoints[1] = 0;
549                                 for (i = USBLP_FIRST_PROTOCOL;
550                                      i <= USBLP_LAST_PROTOCOL; i++) {
551                                         if (usblp->protocol[i].alt_setting >= 0)
552                                                 twoints[1] |= (1<<i);
553                                 }
554
555                                 if (copy_to_user((void __user *)arg,
556                                                 (unsigned char *)twoints,
557                                                 sizeof(twoints))) {
558                                         retval = -EFAULT;
559                                         goto done;
560                                 }
561
562                                 break;
563
564                         case IOCNR_SET_PROTOCOL:
565                                 if (_IOC_DIR(cmd) != _IOC_WRITE) {
566                                         retval = -EINVAL;
567                                         goto done;
568                                 }
569
570 #ifdef DEBUG
571                                 if (arg == -10) {
572                                         usblp_dump(usblp);
573                                         break;
574                                 }
575 #endif
576
577                                 usblp_unlink_urbs(usblp);
578                                 retval = usblp_set_protocol(usblp, arg);
579                                 if (retval < 0) {
580                                         usblp_set_protocol(usblp,
581                                                 usblp->current_protocol);
582                                 }
583                                 break;
584
585                         case IOCNR_HP_SET_CHANNEL:
586                                 if (_IOC_DIR(cmd) != _IOC_WRITE ||
587                                     le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
588                                     usblp->quirks & USBLP_QUIRK_BIDIR) {
589                                         retval = -EINVAL;
590                                         goto done;
591                                 }
592
593                                 err = usblp_hp_channel_change_request(usblp,
594                                         arg, &newChannel);
595                                 if (err < 0) {
596                                         err("usblp%d: error = %d setting "
597                                                 "HP channel",
598                                                 usblp->minor, err);
599                                         retval = -EIO;
600                                         goto done;
601                                 }
602
603                                 dbg("usblp%d requested/got HP channel %ld/%d",
604                                         usblp->minor, arg, newChannel);
605                                 break;
606
607                         case IOCNR_GET_BUS_ADDRESS:
608                                 if (_IOC_DIR(cmd) != _IOC_READ ||
609                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
610                                         retval = -EINVAL;
611                                         goto done;
612                                 }
613
614                                 twoints[0] = usblp->dev->bus->busnum;
615                                 twoints[1] = usblp->dev->devnum;
616                                 if (copy_to_user((void __user *)arg,
617                                                 (unsigned char *)twoints,
618                                                 sizeof(twoints))) {
619                                         retval = -EFAULT;
620                                         goto done;
621                                 }
622
623                                 dbg("usblp%d is bus=%d, device=%d",
624                                         usblp->minor, twoints[0], twoints[1]);
625                                 break;
626
627                         case IOCNR_GET_VID_PID:
628                                 if (_IOC_DIR(cmd) != _IOC_READ ||
629                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
630                                         retval = -EINVAL;
631                                         goto done;
632                                 }
633
634                                 twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
635                                 twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
636                                 if (copy_to_user((void __user *)arg,
637                                                 (unsigned char *)twoints,
638                                                 sizeof(twoints))) {
639                                         retval = -EFAULT;
640                                         goto done;
641                                 }
642
643                                 dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
644                                         usblp->minor, twoints[0], twoints[1]);
645                                 break;
646
647                         case IOCNR_SOFT_RESET:
648                                 if (_IOC_DIR(cmd) != _IOC_NONE) {
649                                         retval = -EINVAL;
650                                         goto done;
651                                 }
652                                 retval = usblp_reset(usblp);
653                                 break;
654                         default:
655                                 retval = -ENOTTY;
656                 }
657         else    /* old-style ioctl value */
658                 switch (cmd) {
659
660                         case LPGETSTATUS:
661                                 if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
662                                         if (printk_ratelimit())
663                                                 printk(KERN_ERR "usblp%d:"
664                                                     "failed reading printer status (%d)\n",
665                                                     usblp->minor, retval);
666                                         retval = -EIO;
667                                         goto done;
668                                 }
669                                 status = *usblp->statusbuf;
670                                 if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
671                                         retval = -EFAULT;
672                                 break;
673
674                         case LPABORT:
675                                 if (arg)
676                                         usblp->flags |= LP_ABORT;
677                                 else
678                                         usblp->flags &= ~LP_ABORT;
679                                 break;
680
681                         default:
682                                 retval = -ENOTTY;
683                 }
684
685 done:
686         mutex_unlock (&usblp->mut);
687         return retval;
688 }
689
690 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
691 {
692         struct urb *urb;
693         char *writebuf;
694
695         if ((writebuf = kmalloc(transfer_length, GFP_KERNEL)) == NULL)
696                 return NULL;
697         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL) {
698                 kfree(writebuf);
699                 return NULL;
700         }
701
702         usb_fill_bulk_urb(urb, usblp->dev,
703                 usb_sndbulkpipe(usblp->dev,
704                  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
705                 writebuf, transfer_length, usblp_bulk_write, usblp);
706         urb->transfer_flags |= URB_FREE_BUFFER;
707
708         return urb;
709 }
710
711 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
712 {
713         struct usblp *usblp = file->private_data;
714         struct urb *writeurb;
715         int rv;
716         int transfer_length;
717         ssize_t writecount = 0;
718
719         if (mutex_lock_interruptible(&usblp->wmut)) {
720                 rv = -EINTR;
721                 goto raise_biglock;
722         }
723         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
724                 goto raise_wait;
725
726         while (writecount < count) {
727                 /*
728                  * Step 1: Submit next block.
729                  */
730                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
731                         transfer_length = USBLP_BUF_SIZE;
732
733                 rv = -ENOMEM;
734                 if ((writeurb = usblp_new_writeurb(usblp, transfer_length)) == NULL)
735                         goto raise_urb;
736                 usb_anchor_urb(writeurb, &usblp->urbs);
737
738                 if (copy_from_user(writeurb->transfer_buffer,
739                                    buffer + writecount, transfer_length)) {
740                         rv = -EFAULT;
741                         goto raise_badaddr;
742                 }
743
744                 spin_lock_irq(&usblp->lock);
745                 usblp->wcomplete = 0;
746                 spin_unlock_irq(&usblp->lock);
747                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
748                         usblp->wstatus = 0;
749                         spin_lock_irq(&usblp->lock);
750                         usblp->no_paper = 0;
751                         usblp->wcomplete = 1;
752                         wake_up(&usblp->wwait);
753                         spin_unlock_irq(&usblp->lock);
754                         if (rv != -ENOMEM)
755                                 rv = -EIO;
756                         goto raise_submit;
757                 }
758
759                 /*
760                  * Step 2: Wait for transfer to end, collect results.
761                  */
762                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
763                 if (rv < 0) {
764                         if (rv == -EAGAIN) {
765                                 /* Presume that it's going to complete well. */
766                                 writecount += transfer_length;
767                         }
768                         if (rv == -ENOSPC) {
769                                 spin_lock_irq(&usblp->lock);
770                                 usblp->no_paper = 1;    /* Mark for poll(2) */
771                                 spin_unlock_irq(&usblp->lock);
772                                 writecount += transfer_length;
773                         }
774                         /* Leave URB dangling, to be cleaned on close. */
775                         goto collect_error;
776                 }
777
778                 if (usblp->wstatus < 0) {
779                         rv = -EIO;
780                         goto collect_error;
781                 }
782                 /*
783                  * This is critical: it must be our URB, not other writer's.
784                  * The wmut exists mainly to cover us here.
785                  */
786                 writecount += usblp->wstatus;
787         }
788
789         mutex_unlock(&usblp->wmut);
790         return writecount;
791
792 raise_submit:
793 raise_badaddr:
794         usb_unanchor_urb(writeurb);
795         usb_free_urb(writeurb);
796 raise_urb:
797 raise_wait:
798 collect_error:          /* Out of raise sequence */
799         mutex_unlock(&usblp->wmut);
800 raise_biglock:
801         return writecount ? writecount : rv;
802 }
803
804 /*
805  * Notice that we fail to restart in a few cases: on EFAULT, on restart
806  * error, etc. This is the historical behaviour. In all such cases we return
807  * EIO, and applications loop in order to get the new read going.
808  */
809 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
810 {
811         struct usblp *usblp = file->private_data;
812         ssize_t count;
813         ssize_t avail;
814         int rv;
815
816         if (!usblp->bidir)
817                 return -EINVAL;
818
819         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
820         if (rv < 0)
821                 return rv;
822
823         if ((avail = usblp->rstatus) < 0) {
824                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
825                     usblp->minor, (int)avail);
826                 usblp_submit_read(usblp);
827                 count = -EIO;
828                 goto done;
829         }
830
831         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
832         if (count != 0 &&
833             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
834                 count = -EFAULT;
835                 goto done;
836         }
837
838         if ((usblp->readcount += count) == avail) {
839                 if (usblp_submit_read(usblp) < 0) {
840                         /* We don't want to leak USB return codes into errno. */
841                         if (count == 0)
842                                 count = -EIO;
843                         goto done;
844                 }
845         }
846
847 done:
848         mutex_unlock (&usblp->mut);
849         return count;
850 }
851
852 /*
853  * Wait for the write path to come idle.
854  * This is called under the ->wmut, so the idle path stays idle.
855  *
856  * Our write path has a peculiar property: it does not buffer like a tty,
857  * but waits for the write to succeed. This allows our ->release to bug out
858  * without waiting for writes to drain. But it obviously does not work
859  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
860  * select(2) or poll(2) to wait for the buffer to drain before closing.
861  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
862  */
863 static int usblp_wwait(struct usblp *usblp, int nonblock)
864 {
865         DECLARE_WAITQUEUE(waita, current);
866         int rc;
867         int err = 0;
868
869         add_wait_queue(&usblp->wwait, &waita);
870         for (;;) {
871                 set_current_state(TASK_INTERRUPTIBLE);
872                 if (mutex_lock_interruptible(&usblp->mut)) {
873                         rc = -EINTR;
874                         break;
875                 }
876                 rc = usblp_wtest(usblp, nonblock);
877                 mutex_unlock(&usblp->mut);
878                 if (rc <= 0)
879                         break;
880
881                 if (usblp->flags & LP_ABORT) {
882                         if (schedule_timeout(msecs_to_jiffies(5000)) == 0) {
883                                 err = usblp_check_status(usblp, err);
884                                 if (err == 1) { /* Paper out */
885                                         rc = -ENOSPC;
886                                         break;
887                                 }
888                         }
889                 } else {
890                         schedule();
891                 }
892         }
893         set_current_state(TASK_RUNNING);
894         remove_wait_queue(&usblp->wwait, &waita);
895         return rc;
896 }
897
898 static int usblp_wtest(struct usblp *usblp, int nonblock)
899 {
900         unsigned long flags;
901
902         if (!usblp->present)
903                 return -ENODEV;
904         if (signal_pending(current))
905                 return -EINTR;
906         spin_lock_irqsave(&usblp->lock, flags);
907         if (usblp->wcomplete) {
908                 spin_unlock_irqrestore(&usblp->lock, flags);
909                 return 0;
910         }
911         spin_unlock_irqrestore(&usblp->lock, flags);
912         if (usblp->sleeping)
913                 return -ENODEV;
914         if (nonblock)
915                 return -EAGAIN;
916         return 1;
917 }
918
919 /*
920  * Wait for read bytes to become available. This probably should have been
921  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
922  * name for functions which lock and return.
923  *
924  * We do not use wait_event_interruptible because it makes locking iffy.
925  */
926 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
927 {
928         DECLARE_WAITQUEUE(waita, current);
929         int rc;
930
931         add_wait_queue(&usblp->rwait, &waita);
932         for (;;) {
933                 if (mutex_lock_interruptible(&usblp->mut)) {
934                         rc = -EINTR;
935                         break;
936                 }
937                 set_current_state(TASK_INTERRUPTIBLE);
938                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
939                         mutex_unlock(&usblp->mut);
940                         break;
941                 }
942                 if (rc == 0)    /* Keep it locked */
943                         break;
944                 mutex_unlock(&usblp->mut);
945                 schedule();
946         }
947         set_current_state(TASK_RUNNING);
948         remove_wait_queue(&usblp->rwait, &waita);
949         return rc;
950 }
951
952 static int usblp_rtest(struct usblp *usblp, int nonblock)
953 {
954         unsigned long flags;
955
956         if (!usblp->present)
957                 return -ENODEV;
958         if (signal_pending(current))
959                 return -EINTR;
960         spin_lock_irqsave(&usblp->lock, flags);
961         if (usblp->rcomplete) {
962                 spin_unlock_irqrestore(&usblp->lock, flags);
963                 return 0;
964         }
965         spin_unlock_irqrestore(&usblp->lock, flags);
966         if (usblp->sleeping)
967                 return -ENODEV;
968         if (nonblock)
969                 return -EAGAIN;
970         return 1;
971 }
972
973 /*
974  * Please check ->bidir and other such things outside for now.
975  */
976 static int usblp_submit_read(struct usblp *usblp)
977 {
978         struct urb *urb;
979         unsigned long flags;
980         int rc;
981
982         rc = -ENOMEM;
983         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
984                 goto raise_urb;
985
986         usb_fill_bulk_urb(urb, usblp->dev,
987                 usb_rcvbulkpipe(usblp->dev,
988                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
989                 usblp->readbuf, USBLP_BUF_SIZE_IN,
990                 usblp_bulk_read, usblp);
991         usb_anchor_urb(urb, &usblp->urbs);
992
993         spin_lock_irqsave(&usblp->lock, flags);
994         usblp->readcount = 0; /* XXX Why here? */
995         usblp->rcomplete = 0;
996         spin_unlock_irqrestore(&usblp->lock, flags);
997         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
998                 dbg("error submitting urb (%d)", rc);
999                 spin_lock_irqsave(&usblp->lock, flags);
1000                 usblp->rstatus = rc;
1001                 usblp->rcomplete = 1;
1002                 spin_unlock_irqrestore(&usblp->lock, flags);
1003                 goto raise_submit;
1004         }
1005
1006         return 0;
1007
1008 raise_submit:
1009         usb_unanchor_urb(urb);
1010         usb_free_urb(urb);
1011 raise_urb:
1012         return rc;
1013 }
1014
1015 /*
1016  * Checks for printers that have quirks, such as requiring unidirectional
1017  * communication but reporting bidirectional; currently some HP printers
1018  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1019  * sent at each open (like some Epsons).
1020  * Returns 1 if found, 0 if not found.
1021  *
1022  * HP recommended that we use the bidirectional interface but
1023  * don't attempt any bulk IN transfers from the IN endpoint.
1024  * Here's some more detail on the problem:
1025  * The problem is not that it isn't bidirectional though. The problem
1026  * is that if you request a device ID, or status information, while
1027  * the buffers are full, the return data will end up in the print data
1028  * buffer. For example if you make sure you never request the device ID
1029  * while you are sending print data, and you don't try to query the
1030  * printer status every couple of milliseconds, you will probably be OK.
1031  */
1032 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
1033 {
1034         int i;
1035
1036         for (i = 0; quirk_printers[i].vendorId; i++) {
1037                 if (vendor == quirk_printers[i].vendorId &&
1038                     product == quirk_printers[i].productId)
1039                         return quirk_printers[i].quirks;
1040         }
1041         return 0;
1042 }
1043
1044 static const struct file_operations usblp_fops = {
1045         .owner =        THIS_MODULE,
1046         .read =         usblp_read,
1047         .write =        usblp_write,
1048         .poll =         usblp_poll,
1049         .unlocked_ioctl =       usblp_ioctl,
1050         .compat_ioctl =         usblp_ioctl,
1051         .open =         usblp_open,
1052         .release =      usblp_release,
1053 };
1054
1055 static struct usb_class_driver usblp_class = {
1056         .name =         "lp%d",
1057         .fops =         &usblp_fops,
1058         .minor_base =   USBLP_MINOR_BASE,
1059 };
1060
1061 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1062 {
1063         struct usb_interface *intf = to_usb_interface(dev);
1064         struct usblp *usblp = usb_get_intfdata (intf);
1065
1066         if (usblp->device_id_string[0] == 0 &&
1067             usblp->device_id_string[1] == 0)
1068                 return 0;
1069
1070         return sprintf(buf, "%s", usblp->device_id_string+2);
1071 }
1072
1073 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1074
1075 static int usblp_probe(struct usb_interface *intf,
1076                        const struct usb_device_id *id)
1077 {
1078         struct usb_device *dev = interface_to_usbdev (intf);
1079         struct usblp *usblp;
1080         int protocol;
1081         int retval;
1082
1083         /* Malloc and start initializing usblp structure so we can use it
1084          * directly. */
1085         usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1086         if (!usblp) {
1087                 retval = -ENOMEM;
1088                 goto abort_ret;
1089         }
1090         usblp->dev = dev;
1091         mutex_init(&usblp->wmut);
1092         mutex_init (&usblp->mut);
1093         spin_lock_init(&usblp->lock);
1094         init_waitqueue_head(&usblp->rwait);
1095         init_waitqueue_head(&usblp->wwait);
1096         init_usb_anchor(&usblp->urbs);
1097         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1098         usblp->intf = intf;
1099
1100         /* Malloc device ID string buffer to the largest expected length,
1101          * since we can re-query it on an ioctl and a dynamic string
1102          * could change in length. */
1103         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1104                 retval = -ENOMEM;
1105                 goto abort;
1106         }
1107
1108         /*
1109          * Allocate read buffer. We somewhat wastefully
1110          * malloc both regardless of bidirectionality, because the
1111          * alternate setting can be changed later via an ioctl.
1112          */
1113         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1114                 retval = -ENOMEM;
1115                 goto abort;
1116         }
1117
1118         /* Allocate buffer for printer status */
1119         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1120         if (!usblp->statusbuf) {
1121                 retval = -ENOMEM;
1122                 goto abort;
1123         }
1124
1125         /* Lookup quirks for this printer. */
1126         usblp->quirks = usblp_quirks(
1127                 le16_to_cpu(dev->descriptor.idVendor),
1128                 le16_to_cpu(dev->descriptor.idProduct));
1129
1130         /* Analyze and pick initial alternate settings and endpoints. */
1131         protocol = usblp_select_alts(usblp);
1132         if (protocol < 0) {
1133                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1134                         le16_to_cpu(dev->descriptor.idVendor),
1135                         le16_to_cpu(dev->descriptor.idProduct));
1136                 retval = -ENODEV;
1137                 goto abort;
1138         }
1139
1140         /* Setup the selected alternate setting and endpoints. */
1141         if (usblp_set_protocol(usblp, protocol) < 0) {
1142                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1143                 goto abort;
1144         }
1145
1146         /* Retrieve and store the device ID string. */
1147         usblp_cache_device_id_string(usblp);
1148         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1149         if (retval)
1150                 goto abort_intfdata;
1151
1152 #ifdef DEBUG
1153         usblp_check_status(usblp, 0);
1154 #endif
1155
1156         usb_set_intfdata (intf, usblp);
1157
1158         usblp->present = 1;
1159
1160         retval = usb_register_dev(intf, &usblp_class);
1161         if (retval) {
1162                 printk(KERN_ERR "usblp: Not able to get a minor"
1163                     " (base %u, slice default): %d\n",
1164                     USBLP_MINOR_BASE, retval);
1165                 goto abort_intfdata;
1166         }
1167         usblp->minor = intf->minor;
1168         printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1169                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1170                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1171                 usblp->ifnum,
1172                 usblp->protocol[usblp->current_protocol].alt_setting,
1173                 usblp->current_protocol,
1174                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1175                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1176
1177         return 0;
1178
1179 abort_intfdata:
1180         usb_set_intfdata (intf, NULL);
1181         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1182 abort:
1183         kfree(usblp->readbuf);
1184         kfree(usblp->statusbuf);
1185         kfree(usblp->device_id_string);
1186         kfree(usblp);
1187 abort_ret:
1188         return retval;
1189 }
1190
1191 /*
1192  * We are a "new" style driver with usb_device_id table,
1193  * but our requirements are too intricate for simple match to handle.
1194  *
1195  * The "proto_bias" option may be used to specify the preferred protocol
1196  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1197  * supports the preferred protocol, then we bind to it.
1198  *
1199  * The best interface for us is 7/1/2, because it is compatible
1200  * with a stream of characters. If we find it, we bind to it.
1201  *
1202  * Note that the people from hpoj.sourceforge.net need to be able to
1203  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1204  *
1205  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1206  * stream-compatible, because this matches the behaviour of the old code.
1207  *
1208  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1209  */
1210 static int usblp_select_alts(struct usblp *usblp)
1211 {
1212         struct usb_interface *if_alt;
1213         struct usb_host_interface *ifd;
1214         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1215         int p, i, e;
1216
1217         if_alt = usblp->intf;
1218
1219         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1220                 usblp->protocol[p].alt_setting = -1;
1221
1222         /* Find out what we have. */
1223         for (i = 0; i < if_alt->num_altsetting; i++) {
1224                 ifd = &if_alt->altsetting[i];
1225
1226                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1227                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1228                                 continue;
1229
1230                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1231                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1232                         continue;
1233
1234                 /* Look for bulk OUT and IN endpoints. */
1235                 epwrite = epread = NULL;
1236                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1237                         epd = &ifd->endpoint[e].desc;
1238
1239                         if (usb_endpoint_is_bulk_out(epd))
1240                                 if (!epwrite)
1241                                         epwrite = epd;
1242
1243                         if (usb_endpoint_is_bulk_in(epd))
1244                                 if (!epread)
1245                                         epread = epd;
1246                 }
1247
1248                 /* Ignore buggy hardware without the right endpoints. */
1249                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1250                         continue;
1251
1252                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1253                  * and buggy bidirectional printers. */
1254                 if (ifd->desc.bInterfaceProtocol == 1) {
1255                         epread = NULL;
1256                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1257                         printk(KERN_INFO "usblp%d: Disabling reads from "
1258                             "problematic bidirectional printer\n",
1259                             usblp->minor);
1260                         epread = NULL;
1261                 }
1262
1263                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1264                                 ifd->desc.bAlternateSetting;
1265                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1266                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1267         }
1268
1269         /* If our requested protocol is supported, then use it. */
1270         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1271             proto_bias <= USBLP_LAST_PROTOCOL &&
1272             usblp->protocol[proto_bias].alt_setting != -1)
1273                 return proto_bias;
1274
1275         /* Ordering is important here. */
1276         if (usblp->protocol[2].alt_setting != -1)
1277                 return 2;
1278         if (usblp->protocol[1].alt_setting != -1)
1279                 return 1;
1280         if (usblp->protocol[3].alt_setting != -1)
1281                 return 3;
1282
1283         /* If nothing is available, then don't bind to this device. */
1284         return -1;
1285 }
1286
1287 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1288 {
1289         int r, alts;
1290
1291         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1292                 return -EINVAL;
1293
1294         alts = usblp->protocol[protocol].alt_setting;
1295         if (alts < 0)
1296                 return -EINVAL;
1297         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1298         if (r < 0) {
1299                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1300                         alts, usblp->ifnum);
1301                 return r;
1302         }
1303
1304         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1305         usblp->current_protocol = protocol;
1306         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1307         return 0;
1308 }
1309
1310 /* Retrieves and caches device ID string.
1311  * Returns length, including length bytes but not null terminator.
1312  * On error, returns a negative errno value. */
1313 static int usblp_cache_device_id_string(struct usblp *usblp)
1314 {
1315         int err, length;
1316
1317         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1318         if (err < 0) {
1319                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1320                         usblp->minor, err);
1321                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1322                 return -EIO;
1323         }
1324
1325         /* First two bytes are length in big-endian.
1326          * They count themselves, and we copy them into
1327          * the user's buffer. */
1328         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1329         if (length < 2)
1330                 length = 2;
1331         else if (length >= USBLP_DEVICE_ID_SIZE)
1332                 length = USBLP_DEVICE_ID_SIZE - 1;
1333         usblp->device_id_string[length] = '\0';
1334
1335         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1336                 usblp->minor, length, &usblp->device_id_string[2]);
1337
1338         return length;
1339 }
1340
1341 static void usblp_disconnect(struct usb_interface *intf)
1342 {
1343         struct usblp *usblp = usb_get_intfdata (intf);
1344
1345         usb_deregister_dev(intf, &usblp_class);
1346
1347         if (!usblp || !usblp->dev) {
1348                 err("bogus disconnect");
1349                 BUG ();
1350         }
1351
1352         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1353
1354         mutex_lock (&usblp_mutex);
1355         mutex_lock (&usblp->mut);
1356         usblp->present = 0;
1357         wake_up(&usblp->wwait);
1358         wake_up(&usblp->rwait);
1359         usb_set_intfdata (intf, NULL);
1360
1361         usblp_unlink_urbs(usblp);
1362         mutex_unlock (&usblp->mut);
1363
1364         if (!usblp->used)
1365                 usblp_cleanup (usblp);
1366         mutex_unlock (&usblp_mutex);
1367 }
1368
1369 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1370 {
1371         struct usblp *usblp = usb_get_intfdata (intf);
1372
1373         /* we take no more IO */
1374         usblp->sleeping = 1;
1375         usblp_unlink_urbs(usblp);
1376 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1377         /* not strictly necessary, but just in case */
1378         wake_up(&usblp->wwait);
1379         wake_up(&usblp->rwait);
1380 #endif
1381
1382         return 0;
1383 }
1384
1385 static int usblp_resume (struct usb_interface *intf)
1386 {
1387         struct usblp *usblp = usb_get_intfdata (intf);
1388         int r;
1389
1390         usblp->sleeping = 0;
1391         r = handle_bidir (usblp);
1392
1393         return r;
1394 }
1395
1396 static struct usb_device_id usblp_ids [] = {
1397         { USB_DEVICE_INFO(7, 1, 1) },
1398         { USB_DEVICE_INFO(7, 1, 2) },
1399         { USB_DEVICE_INFO(7, 1, 3) },
1400         { USB_INTERFACE_INFO(7, 1, 1) },
1401         { USB_INTERFACE_INFO(7, 1, 2) },
1402         { USB_INTERFACE_INFO(7, 1, 3) },
1403         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1404         { }                                             /* Terminating entry */
1405 };
1406
1407 MODULE_DEVICE_TABLE (usb, usblp_ids);
1408
1409 static struct usb_driver usblp_driver = {
1410         .name =         "usblp",
1411         .probe =        usblp_probe,
1412         .disconnect =   usblp_disconnect,
1413         .suspend =      usblp_suspend,
1414         .resume =       usblp_resume,
1415         .id_table =     usblp_ids,
1416         .supports_autosuspend = 1,
1417 };
1418
1419 static int __init usblp_init(void)
1420 {
1421         return usb_register(&usblp_driver);
1422 }
1423
1424 static void __exit usblp_exit(void)
1425 {
1426         usb_deregister(&usblp_driver);
1427 }
1428
1429 module_init(usblp_init);
1430 module_exit(usblp_exit);
1431
1432 MODULE_AUTHOR( DRIVER_AUTHOR );
1433 MODULE_DESCRIPTION( DRIVER_DESC );
1434 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1435 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1436 MODULE_LICENSE("GPL");