Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2

Linux/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@ucw.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_alloc_coherent() 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/slab.h>
 56 #include <linux/lp.h>
 57 #include <linux/mutex.h>
 58 #undef DEBUG
 59 #include <linux/usb.h>
 60 #include <linux/ratelimit.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           no_paper;               /* Paper Out happened */
167         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
168                                                         /* first 2 bytes are (big-endian) length */
169 };
170 
171 #ifdef DEBUG
172 static void usblp_dump(struct usblp *usblp)
173 {
174         struct device *dev = &usblp->intf->dev;
175         int p;
176 
177         dev_dbg(dev, "usblp=0x%p\n", usblp);
178         dev_dbg(dev, "dev=0x%p\n", usblp->dev);
179         dev_dbg(dev, "present=%d\n", usblp->present);
180         dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
181         dev_dbg(dev, "readcount=%d\n", usblp->readcount);
182         dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
183         for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
184                 dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
185                         usblp->protocol[p].alt_setting);
186                 dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
187                         usblp->protocol[p].epwrite);
188                 dev_dbg(dev, "protocol[%d].epread=%p\n", p,
189                         usblp->protocol[p].epread);
190         }
191         dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
192         dev_dbg(dev, "minor=%d\n", usblp->minor);
193         dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
194         dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
195         dev_dbg(dev, "quirks=%d\n", usblp->quirks);
196         dev_dbg(dev, "used=%d\n", usblp->used);
197         dev_dbg(dev, "bidir=%d\n", usblp->bidir);
198         dev_dbg(dev, "device_id_string=\"%s\"\n",
199                 usblp->device_id_string ?
200                         usblp->device_id_string + 2 :
201                         (unsigned char *)"(null)");
202 }
203 #endif
204 
205 /* Quirks: various printer quirks are handled by this table & its flags. */
206 
207 struct quirk_printer_struct {
208         __u16 vendorId;
209         __u16 productId;
210         unsigned int quirks;
211 };
212 
213 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
214 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
215 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
216 
217 static const struct quirk_printer_struct quirk_printers[] = {
218         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
219         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
220         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
221         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
222         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
223         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
224         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
225         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
226         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
227         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
228         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
229         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
230         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
231         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
232         { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
233         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
234         { 0, 0 }
235 };
236 
237 static int usblp_wwait(struct usblp *usblp, int nonblock);
238 static int usblp_wtest(struct usblp *usblp, int nonblock);
239 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
240 static int usblp_rtest(struct usblp *usblp, int nonblock);
241 static int usblp_submit_read(struct usblp *usblp);
242 static int usblp_select_alts(struct usblp *usblp);
243 static int usblp_set_protocol(struct usblp *usblp, int protocol);
244 static int usblp_cache_device_id_string(struct usblp *usblp);
245 
246 /* forward reference to make our lives easier */
247 static struct usb_driver usblp_driver;
248 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
249 
250 /*
251  * Functions for usblp control messages.
252  */
253 
254 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
255 {
256         int retval;
257         int index = usblp->ifnum;
258 
259         /* High byte has the interface index.
260            Low byte has the alternate setting.
261          */
262         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
263                 index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
264 
265         retval = usb_control_msg(usblp->dev,
266                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
267                 request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
268         dev_dbg(&usblp->intf->dev,
269                 "usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
270                 request, !!dir, recip, value, index, len, retval);
271         return retval < 0 ? retval : 0;
272 }
273 
274 #define usblp_read_status(usblp, status)\
275         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
276 #define usblp_get_id(usblp, config, id, maxlen)\
277         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
278 #define usblp_reset(usblp)\
279         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
280 
281 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
282         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
283 
284 /*
285  * See the description for usblp_select_alts() below for the usage
286  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
287  * case of any trouble.
288  */
289 static int proto_bias = -1;
290 
291 /*
292  * URB callback.
293  */
294 
295 static void usblp_bulk_read(struct urb *urb)
296 {
297         struct usblp *usblp = urb->context;
298         int status = urb->status;
299 
300         if (usblp->present && usblp->used) {
301                 if (status)
302                         printk(KERN_WARNING "usblp%d: "
303                             "nonzero read bulk status received: %d\n",
304                             usblp->minor, status);
305         }
306         spin_lock(&usblp->lock);
307         if (status < 0)
308                 usblp->rstatus = status;
309         else
310                 usblp->rstatus = urb->actual_length;
311         usblp->rcomplete = 1;
312         wake_up(&usblp->rwait);
313         spin_unlock(&usblp->lock);
314 
315         usb_free_urb(urb);
316 }
317 
318 static void usblp_bulk_write(struct urb *urb)
319 {
320         struct usblp *usblp = urb->context;
321         int status = urb->status;
322 
323         if (usblp->present && usblp->used) {
324                 if (status)
325                         printk(KERN_WARNING "usblp%d: "
326                             "nonzero write bulk status received: %d\n",
327                             usblp->minor, status);
328         }
329         spin_lock(&usblp->lock);
330         if (status < 0)
331                 usblp->wstatus = status;
332         else
333                 usblp->wstatus = urb->actual_length;
334         usblp->no_paper = 0;
335         usblp->wcomplete = 1;
336         wake_up(&usblp->wwait);
337         spin_unlock(&usblp->lock);
338 
339         usb_free_urb(urb);
340 }
341 
342 /*
343  * Get and print printer errors.
344  */
345 
346 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
347 
348 static int usblp_check_status(struct usblp *usblp, int err)
349 {
350         unsigned char status, newerr = 0;
351         int error;
352 
353         mutex_lock(&usblp->mut);
354         if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
355                 mutex_unlock(&usblp->mut);
356                 printk_ratelimited(KERN_ERR
357                                 "usblp%d: error %d reading printer status\n",
358                                 usblp->minor, error);
359                 return 0;
360         }
361         status = *usblp->statusbuf;
362         mutex_unlock(&usblp->mut);
363 
364         if (~status & LP_PERRORP)
365                 newerr = 3;
366         if (status & LP_POUTPA)
367                 newerr = 1;
368         if (~status & LP_PSELECD)
369                 newerr = 2;
370 
371         if (newerr != err) {
372                 printk(KERN_INFO "usblp%d: %s\n",
373                    usblp->minor, usblp_messages[newerr]);
374         }
375 
376         return newerr;
377 }
378 
379 static int handle_bidir(struct usblp *usblp)
380 {
381         if (usblp->bidir && usblp->used) {
382                 if (usblp_submit_read(usblp) < 0)
383                         return -EIO;
384         }
385         return 0;
386 }
387 
388 /*
389  * File op functions.
390  */
391 
392 static int usblp_open(struct inode *inode, struct file *file)
393 {
394         int minor = iminor(inode);
395         struct usblp *usblp;
396         struct usb_interface *intf;
397         int retval;
398 
399         if (minor < 0)
400                 return -ENODEV;
401 
402         mutex_lock(&usblp_mutex);
403 
404         retval = -ENODEV;
405         intf = usb_find_interface(&usblp_driver, minor);
406         if (!intf)
407                 goto out;
408         usblp = usb_get_intfdata(intf);
409         if (!usblp || !usblp->dev || !usblp->present)
410                 goto out;
411 
412         retval = -EBUSY;
413         if (usblp->used)
414                 goto out;
415 
416         /*
417          * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
418          *  - We do not want persistent state which close(2) does not clear
419          *  - It is not used anyway, according to CUPS people
420          */
421 
422         retval = usb_autopm_get_interface(intf);
423         if (retval < 0)
424                 goto out;
425         usblp->used = 1;
426         file->private_data = usblp;
427 
428         usblp->wcomplete = 1; /* we begin writeable */
429         usblp->wstatus = 0;
430         usblp->rcomplete = 0;
431 
432         if (handle_bidir(usblp) < 0) {
433                 usb_autopm_put_interface(intf);
434                 usblp->used = 0;
435                 file->private_data = NULL;
436                 retval = -EIO;
437         }
438 out:
439         mutex_unlock(&usblp_mutex);
440         return retval;
441 }
442 
443 static void usblp_cleanup(struct usblp *usblp)
444 {
445         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
446 
447         kfree(usblp->readbuf);
448         kfree(usblp->device_id_string);
449         kfree(usblp->statusbuf);
450         kfree(usblp);
451 }
452 
453 static void usblp_unlink_urbs(struct usblp *usblp)
454 {
455         usb_kill_anchored_urbs(&usblp->urbs);
456 }
457 
458 static int usblp_release(struct inode *inode, struct file *file)
459 {
460         struct usblp *usblp = file->private_data;
461 
462         usblp->flags &= ~LP_ABORT;
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) ? POLLIN  | POLLRDNORM : 0) |
487            ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
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         dev_dbg(&usblp->intf->dev,
508                 "usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
509                 _IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
510 
511         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
512 
513                 switch (_IOC_NR(cmd)) {
514 
515                 case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
516                         if (_IOC_DIR(cmd) != _IOC_READ) {
517                                 retval = -EINVAL;
518                                 goto done;
519                         }
520 
521                         length = usblp_cache_device_id_string(usblp);
522                         if (length < 0) {
523                                 retval = length;
524                                 goto done;
525                         }
526                         if (length > _IOC_SIZE(cmd))
527                                 length = _IOC_SIZE(cmd); /* truncate */
528 
529                         if (copy_to_user((void __user *) arg,
530                                         usblp->device_id_string,
531                                         (unsigned long) length)) {
532                                 retval = -EFAULT;
533                                 goto done;
534                         }
535 
536                         break;
537 
538                 case IOCNR_GET_PROTOCOLS:
539                         if (_IOC_DIR(cmd) != _IOC_READ ||
540                             _IOC_SIZE(cmd) < sizeof(twoints)) {
541                                 retval = -EINVAL;
542                                 goto done;
543                         }
544 
545                         twoints[0] = usblp->current_protocol;
546                         twoints[1] = 0;
547                         for (i = USBLP_FIRST_PROTOCOL;
548                              i <= USBLP_LAST_PROTOCOL; i++) {
549                                 if (usblp->protocol[i].alt_setting >= 0)
550                                         twoints[1] |= (1<<i);
551                         }
552 
553                         if (copy_to_user((void __user *)arg,
554                                         (unsigned char *)twoints,
555                                         sizeof(twoints))) {
556                                 retval = -EFAULT;
557                                 goto done;
558                         }
559 
560                         break;
561 
562                 case IOCNR_SET_PROTOCOL:
563                         if (_IOC_DIR(cmd) != _IOC_WRITE) {
564                                 retval = -EINVAL;
565                                 goto done;
566                         }
567 
568 #ifdef DEBUG
569                         if (arg == -10) {
570                                 usblp_dump(usblp);
571                                 break;
572                         }
573 #endif
574 
575                         usblp_unlink_urbs(usblp);
576                         retval = usblp_set_protocol(usblp, arg);
577                         if (retval < 0) {
578                                 usblp_set_protocol(usblp,
579                                         usblp->current_protocol);
580                         }
581                         break;
582 
583                 case IOCNR_HP_SET_CHANNEL:
584                         if (_IOC_DIR(cmd) != _IOC_WRITE ||
585                             le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
586                             usblp->quirks & USBLP_QUIRK_BIDIR) {
587                                 retval = -EINVAL;
588                                 goto done;
589                         }
590 
591                         err = usblp_hp_channel_change_request(usblp,
592                                 arg, &newChannel);
593                         if (err < 0) {
594                                 dev_err(&usblp->dev->dev,
595                                         "usblp%d: error = %d setting "
596                                         "HP channel\n",
597                                         usblp->minor, err);
598                                 retval = -EIO;
599                                 goto done;
600                         }
601 
602                         dev_dbg(&usblp->intf->dev,
603                                 "usblp%d requested/got HP channel %ld/%d\n",
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                         dev_dbg(&usblp->intf->dev,
624                                 "usblp%d is bus=%d, device=%d\n",
625                                 usblp->minor, twoints[0], twoints[1]);
626                         break;
627 
628                 case IOCNR_GET_VID_PID:
629                         if (_IOC_DIR(cmd) != _IOC_READ ||
630                             _IOC_SIZE(cmd) < sizeof(twoints)) {
631                                 retval = -EINVAL;
632                                 goto done;
633                         }
634 
635                         twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
636                         twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
637                         if (copy_to_user((void __user *)arg,
638                                         (unsigned char *)twoints,
639                                         sizeof(twoints))) {
640                                 retval = -EFAULT;
641                                 goto done;
642                         }
643 
644                         dev_dbg(&usblp->intf->dev,
645                                 "usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
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                         retval = usblp_read_status(usblp, usblp->statusbuf);
664                         if (retval) {
665                                 printk_ratelimited(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                 case LPABORT:
677                         if (arg)
678                                 usblp->flags |= LP_ABORT;
679                         else
680                                 usblp->flags &= ~LP_ABORT;
681                         break;
682 
683                 default:
684                         retval = -ENOTTY;
685                 }
686 
687 done:
688         mutex_unlock(&usblp->mut);
689         return retval;
690 }
691 
692 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
693 {
694         struct urb *urb;
695         char *writebuf;
696 
697         writebuf = kmalloc(transfer_length, GFP_KERNEL);
698         if (writebuf == NULL)
699                 return NULL;
700         urb = usb_alloc_urb(0, GFP_KERNEL);
701         if (urb == NULL) {
702                 kfree(writebuf);
703                 return NULL;
704         }
705 
706         usb_fill_bulk_urb(urb, usblp->dev,
707                 usb_sndbulkpipe(usblp->dev,
708                  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
709                 writebuf, transfer_length, usblp_bulk_write, usblp);
710         urb->transfer_flags |= URB_FREE_BUFFER;
711 
712         return urb;
713 }
714 
715 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
716 {
717         struct usblp *usblp = file->private_data;
718         struct urb *writeurb;
719         int rv;
720         int transfer_length;
721         ssize_t writecount = 0;
722 
723         if (mutex_lock_interruptible(&usblp->wmut)) {
724                 rv = -EINTR;
725                 goto raise_biglock;
726         }
727         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
728                 goto raise_wait;
729 
730         while (writecount < count) {
731                 /*
732                  * Step 1: Submit next block.
733                  */
734                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
735                         transfer_length = USBLP_BUF_SIZE;
736 
737                 rv = -ENOMEM;
738                 writeurb = usblp_new_writeurb(usblp, transfer_length);
739                 if (writeurb == NULL)
740                         goto raise_urb;
741                 usb_anchor_urb(writeurb, &usblp->urbs);
742 
743                 if (copy_from_user(writeurb->transfer_buffer,
744                                    buffer + writecount, transfer_length)) {
745                         rv = -EFAULT;
746                         goto raise_badaddr;
747                 }
748 
749                 spin_lock_irq(&usblp->lock);
750                 usblp->wcomplete = 0;
751                 spin_unlock_irq(&usblp->lock);
752                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
753                         usblp->wstatus = 0;
754                         spin_lock_irq(&usblp->lock);
755                         usblp->no_paper = 0;
756                         usblp->wcomplete = 1;
757                         wake_up(&usblp->wwait);
758                         spin_unlock_irq(&usblp->lock);
759                         if (rv != -ENOMEM)
760                                 rv = -EIO;
761                         goto raise_submit;
762                 }
763 
764                 /*
765                  * Step 2: Wait for transfer to end, collect results.
766                  */
767                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
768                 if (rv < 0) {
769                         if (rv == -EAGAIN) {
770                                 /* Presume that it's going to complete well. */
771                                 writecount += transfer_length;
772                         }
773                         if (rv == -ENOSPC) {
774                                 spin_lock_irq(&usblp->lock);
775                                 usblp->no_paper = 1;    /* Mark for poll(2) */
776                                 spin_unlock_irq(&usblp->lock);
777                                 writecount += transfer_length;
778                         }
779                         /* Leave URB dangling, to be cleaned on close. */
780                         goto collect_error;
781                 }
782 
783                 if (usblp->wstatus < 0) {
784                         rv = -EIO;
785                         goto collect_error;
786                 }
787                 /*
788                  * This is critical: it must be our URB, not other writer's.
789                  * The wmut exists mainly to cover us here.
790                  */
791                 writecount += usblp->wstatus;
792         }
793 
794         mutex_unlock(&usblp->wmut);
795         return writecount;
796 
797 raise_submit:
798 raise_badaddr:
799         usb_unanchor_urb(writeurb);
800         usb_free_urb(writeurb);
801 raise_urb:
802 raise_wait:
803 collect_error:          /* Out of raise sequence */
804         mutex_unlock(&usblp->wmut);
805 raise_biglock:
806         return writecount ? writecount : rv;
807 }
808 
809 /*
810  * Notice that we fail to restart in a few cases: on EFAULT, on restart
811  * error, etc. This is the historical behaviour. In all such cases we return
812  * EIO, and applications loop in order to get the new read going.
813  */
814 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
815 {
816         struct usblp *usblp = file->private_data;
817         ssize_t count;
818         ssize_t avail;
819         int rv;
820 
821         if (!usblp->bidir)
822                 return -EINVAL;
823 
824         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
825         if (rv < 0)
826                 return rv;
827 
828         if ((avail = usblp->rstatus) < 0) {
829                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
830                     usblp->minor, (int)avail);
831                 usblp_submit_read(usblp);
832                 count = -EIO;
833                 goto done;
834         }
835 
836         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
837         if (count != 0 &&
838             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
839                 count = -EFAULT;
840                 goto done;
841         }
842 
843         if ((usblp->readcount += count) == avail) {
844                 if (usblp_submit_read(usblp) < 0) {
845                         /* We don't want to leak USB return codes into errno. */
846                         if (count == 0)
847                                 count = -EIO;
848                         goto done;
849                 }
850         }
851 
852 done:
853         mutex_unlock(&usblp->mut);
854         return count;
855 }
856 
857 /*
858  * Wait for the write path to come idle.
859  * This is called under the ->wmut, so the idle path stays idle.
860  *
861  * Our write path has a peculiar property: it does not buffer like a tty,
862  * but waits for the write to succeed. This allows our ->release to bug out
863  * without waiting for writes to drain. But it obviously does not work
864  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
865  * select(2) or poll(2) to wait for the buffer to drain before closing.
866  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
867  */
868 static int usblp_wwait(struct usblp *usblp, int nonblock)
869 {
870         DECLARE_WAITQUEUE(waita, current);
871         int rc;
872         int err = 0;
873 
874         add_wait_queue(&usblp->wwait, &waita);
875         for (;;) {
876                 set_current_state(TASK_INTERRUPTIBLE);
877                 if (mutex_lock_interruptible(&usblp->mut)) {
878                         rc = -EINTR;
879                         break;
880                 }
881                 rc = usblp_wtest(usblp, nonblock);
882                 mutex_unlock(&usblp->mut);
883                 if (rc <= 0)
884                         break;
885 
886                 if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
887                         if (usblp->flags & LP_ABORT) {
888                                 err = usblp_check_status(usblp, err);
889                                 if (err == 1) { /* Paper out */
890                                         rc = -ENOSPC;
891                                         break;
892                                 }
893                         } else {
894                                 /* Prod the printer, Gentoo#251237. */
895                                 mutex_lock(&usblp->mut);
896                                 usblp_read_status(usblp, usblp->statusbuf);
897                                 mutex_unlock(&usblp->mut);
898                         }
899                 }
900         }
901         set_current_state(TASK_RUNNING);
902         remove_wait_queue(&usblp->wwait, &waita);
903         return rc;
904 }
905 
906 static int usblp_wtest(struct usblp *usblp, int nonblock)
907 {
908         unsigned long flags;
909 
910         if (!usblp->present)
911                 return -ENODEV;
912         if (signal_pending(current))
913                 return -EINTR;
914         spin_lock_irqsave(&usblp->lock, flags);
915         if (usblp->wcomplete) {
916                 spin_unlock_irqrestore(&usblp->lock, flags);
917                 return 0;
918         }
919         spin_unlock_irqrestore(&usblp->lock, flags);
920         if (nonblock)
921                 return -EAGAIN;
922         return 1;
923 }
924 
925 /*
926  * Wait for read bytes to become available. This probably should have been
927  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
928  * name for functions which lock and return.
929  *
930  * We do not use wait_event_interruptible because it makes locking iffy.
931  */
932 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
933 {
934         DECLARE_WAITQUEUE(waita, current);
935         int rc;
936 
937         add_wait_queue(&usblp->rwait, &waita);
938         for (;;) {
939                 if (mutex_lock_interruptible(&usblp->mut)) {
940                         rc = -EINTR;
941                         break;
942                 }
943                 set_current_state(TASK_INTERRUPTIBLE);
944                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
945                         mutex_unlock(&usblp->mut);
946                         break;
947                 }
948                 if (rc == 0)    /* Keep it locked */
949                         break;
950                 mutex_unlock(&usblp->mut);
951                 schedule();
952         }
953         set_current_state(TASK_RUNNING);
954         remove_wait_queue(&usblp->rwait, &waita);
955         return rc;
956 }
957 
958 static int usblp_rtest(struct usblp *usblp, int nonblock)
959 {
960         unsigned long flags;
961 
962         if (!usblp->present)
963                 return -ENODEV;
964         if (signal_pending(current))
965                 return -EINTR;
966         spin_lock_irqsave(&usblp->lock, flags);
967         if (usblp->rcomplete) {
968                 spin_unlock_irqrestore(&usblp->lock, flags);
969                 return 0;
970         }
971         spin_unlock_irqrestore(&usblp->lock, flags);
972         if (nonblock)
973                 return -EAGAIN;
974         return 1;
975 }
976 
977 /*
978  * Please check ->bidir and other such things outside for now.
979  */
980 static int usblp_submit_read(struct usblp *usblp)
981 {
982         struct urb *urb;
983         unsigned long flags;
984         int rc;
985 
986         rc = -ENOMEM;
987         urb = usb_alloc_urb(0, GFP_KERNEL);
988         if (urb == NULL)
989                 goto raise_urb;
990 
991         usb_fill_bulk_urb(urb, usblp->dev,
992                 usb_rcvbulkpipe(usblp->dev,
993                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
994                 usblp->readbuf, USBLP_BUF_SIZE_IN,
995                 usblp_bulk_read, usblp);
996         usb_anchor_urb(urb, &usblp->urbs);
997 
998         spin_lock_irqsave(&usblp->lock, flags);
999         usblp->readcount = 0; /* XXX Why here? */
1000         usblp->rcomplete = 0;
1001         spin_unlock_irqrestore(&usblp->lock, flags);
1002         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1003                 dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1004                 spin_lock_irqsave(&usblp->lock, flags);
1005                 usblp->rstatus = rc;
1006                 usblp->rcomplete = 1;
1007                 spin_unlock_irqrestore(&usblp->lock, flags);
1008                 goto raise_submit;
1009         }
1010 
1011         return 0;
1012 
1013 raise_submit:
1014         usb_unanchor_urb(urb);
1015         usb_free_urb(urb);
1016 raise_urb:
1017         return rc;
1018 }
1019 
1020 /*
1021  * Checks for printers that have quirks, such as requiring unidirectional
1022  * communication but reporting bidirectional; currently some HP printers
1023  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1024  * sent at each open (like some Epsons).
1025  * Returns 1 if found, 0 if not found.
1026  *
1027  * HP recommended that we use the bidirectional interface but
1028  * don't attempt any bulk IN transfers from the IN endpoint.
1029  * Here's some more detail on the problem:
1030  * The problem is not that it isn't bidirectional though. The problem
1031  * is that if you request a device ID, or status information, while
1032  * the buffers are full, the return data will end up in the print data
1033  * buffer. For example if you make sure you never request the device ID
1034  * while you are sending print data, and you don't try to query the
1035  * printer status every couple of milliseconds, you will probably be OK.
1036  */
1037 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1038 {
1039         int i;
1040 
1041         for (i = 0; quirk_printers[i].vendorId; i++) {
1042                 if (vendor == quirk_printers[i].vendorId &&
1043                     product == quirk_printers[i].productId)
1044                         return quirk_printers[i].quirks;
1045         }
1046         return 0;
1047 }
1048 
1049 static const struct file_operations usblp_fops = {
1050         .owner =        THIS_MODULE,
1051         .read =         usblp_read,
1052         .write =        usblp_write,
1053         .poll =         usblp_poll,
1054         .unlocked_ioctl =       usblp_ioctl,
1055         .compat_ioctl =         usblp_ioctl,
1056         .open =         usblp_open,
1057         .release =      usblp_release,
1058         .llseek =       noop_llseek,
1059 };
1060 
1061 static char *usblp_devnode(struct device *dev, umode_t *mode)
1062 {
1063         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1064 }
1065 
1066 static struct usb_class_driver usblp_class = {
1067         .name =         "lp%d",
1068         .devnode =      usblp_devnode,
1069         .fops =         &usblp_fops,
1070         .minor_base =   USBLP_MINOR_BASE,
1071 };
1072 
1073 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1074 {
1075         struct usb_interface *intf = to_usb_interface(dev);
1076         struct usblp *usblp = usb_get_intfdata(intf);
1077 
1078         if (usblp->device_id_string[0] == 0 &&
1079             usblp->device_id_string[1] == 0)
1080                 return 0;
1081 
1082         return sprintf(buf, "%s", usblp->device_id_string+2);
1083 }
1084 
1085 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1086 
1087 static int usblp_probe(struct usb_interface *intf,
1088                        const struct usb_device_id *id)
1089 {
1090         struct usb_device *dev = interface_to_usbdev(intf);
1091         struct usblp *usblp;
1092         int protocol;
1093         int retval;
1094 
1095         /* Malloc and start initializing usblp structure so we can use it
1096          * directly. */
1097         usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1098         if (!usblp) {
1099                 retval = -ENOMEM;
1100                 goto abort_ret;
1101         }
1102         usblp->dev = dev;
1103         mutex_init(&usblp->wmut);
1104         mutex_init(&usblp->mut);
1105         spin_lock_init(&usblp->lock);
1106         init_waitqueue_head(&usblp->rwait);
1107         init_waitqueue_head(&usblp->wwait);
1108         init_usb_anchor(&usblp->urbs);
1109         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1110         usblp->intf = intf;
1111 
1112         /* Malloc device ID string buffer to the largest expected length,
1113          * since we can re-query it on an ioctl and a dynamic string
1114          * could change in length. */
1115         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1116                 retval = -ENOMEM;
1117                 goto abort;
1118         }
1119 
1120         /*
1121          * Allocate read buffer. We somewhat wastefully
1122          * malloc both regardless of bidirectionality, because the
1123          * alternate setting can be changed later via an ioctl.
1124          */
1125         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1126                 retval = -ENOMEM;
1127                 goto abort;
1128         }
1129 
1130         /* Allocate buffer for printer status */
1131         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1132         if (!usblp->statusbuf) {
1133                 retval = -ENOMEM;
1134                 goto abort;
1135         }
1136 
1137         /* Lookup quirks for this printer. */
1138         usblp->quirks = usblp_quirks(
1139                 le16_to_cpu(dev->descriptor.idVendor),
1140                 le16_to_cpu(dev->descriptor.idProduct));
1141 
1142         /* Analyze and pick initial alternate settings and endpoints. */
1143         protocol = usblp_select_alts(usblp);
1144         if (protocol < 0) {
1145                 dev_dbg(&intf->dev,
1146                         "incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1147                         le16_to_cpu(dev->descriptor.idVendor),
1148                         le16_to_cpu(dev->descriptor.idProduct));
1149                 retval = -ENODEV;
1150                 goto abort;
1151         }
1152 
1153         /* Setup the selected alternate setting and endpoints. */
1154         if (usblp_set_protocol(usblp, protocol) < 0) {
1155                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1156                 goto abort;
1157         }
1158 
1159         /* Retrieve and store the device ID string. */
1160         usblp_cache_device_id_string(usblp);
1161         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1162         if (retval)
1163                 goto abort_intfdata;
1164 
1165 #ifdef DEBUG
1166         usblp_check_status(usblp, 0);
1167 #endif
1168 
1169         usb_set_intfdata(intf, usblp);
1170 
1171         usblp->present = 1;
1172 
1173         retval = usb_register_dev(intf, &usblp_class);
1174         if (retval) {
1175                 dev_err(&intf->dev,
1176                         "usblp: Not able to get a minor (base %u, slice default): %d\n",
1177                         USBLP_MINOR_BASE, retval);
1178                 goto abort_intfdata;
1179         }
1180         usblp->minor = intf->minor;
1181         dev_info(&intf->dev,
1182                 "usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1183                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1184                 usblp->ifnum,
1185                 usblp->protocol[usblp->current_protocol].alt_setting,
1186                 usblp->current_protocol,
1187                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1188                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1189 
1190         return 0;
1191 
1192 abort_intfdata:
1193         usb_set_intfdata(intf, NULL);
1194         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1195 abort:
1196         kfree(usblp->readbuf);
1197         kfree(usblp->statusbuf);
1198         kfree(usblp->device_id_string);
1199         kfree(usblp);
1200 abort_ret:
1201         return retval;
1202 }
1203 
1204 /*
1205  * We are a "new" style driver with usb_device_id table,
1206  * but our requirements are too intricate for simple match to handle.
1207  *
1208  * The "proto_bias" option may be used to specify the preferred protocol
1209  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1210  * supports the preferred protocol, then we bind to it.
1211  *
1212  * The best interface for us is 7/1/2, because it is compatible
1213  * with a stream of characters. If we find it, we bind to it.
1214  *
1215  * Note that the people from hpoj.sourceforge.net need to be able to
1216  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1217  *
1218  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1219  * stream-compatible, because this matches the behaviour of the old code.
1220  *
1221  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1222  */
1223 static int usblp_select_alts(struct usblp *usblp)
1224 {
1225         struct usb_interface *if_alt;
1226         struct usb_host_interface *ifd;
1227         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1228         int p, i, e;
1229 
1230         if_alt = usblp->intf;
1231 
1232         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1233                 usblp->protocol[p].alt_setting = -1;
1234 
1235         /* Find out what we have. */
1236         for (i = 0; i < if_alt->num_altsetting; i++) {
1237                 ifd = &if_alt->altsetting[i];
1238 
1239                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1240                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1241                                 continue;
1242 
1243                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1244                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1245                         continue;
1246 
1247                 /* Look for bulk OUT and IN endpoints. */
1248                 epwrite = epread = NULL;
1249                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1250                         epd = &ifd->endpoint[e].desc;
1251 
1252                         if (usb_endpoint_is_bulk_out(epd))
1253                                 if (!epwrite)
1254                                         epwrite = epd;
1255 
1256                         if (usb_endpoint_is_bulk_in(epd))
1257                                 if (!epread)
1258                                         epread = epd;
1259                 }
1260 
1261                 /* Ignore buggy hardware without the right endpoints. */
1262                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1263                         continue;
1264 
1265                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1266                  * and buggy bidirectional printers. */
1267                 if (ifd->desc.bInterfaceProtocol == 1) {
1268                         epread = NULL;
1269                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1270                         printk(KERN_INFO "usblp%d: Disabling reads from "
1271                             "problematic bidirectional printer\n",
1272                             usblp->minor);
1273                         epread = NULL;
1274                 }
1275 
1276                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1277                                 ifd->desc.bAlternateSetting;
1278                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1279                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1280         }
1281 
1282         /* If our requested protocol is supported, then use it. */
1283         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1284             proto_bias <= USBLP_LAST_PROTOCOL &&
1285             usblp->protocol[proto_bias].alt_setting != -1)
1286                 return proto_bias;
1287 
1288         /* Ordering is important here. */
1289         if (usblp->protocol[2].alt_setting != -1)
1290                 return 2;
1291         if (usblp->protocol[1].alt_setting != -1)
1292                 return 1;
1293         if (usblp->protocol[3].alt_setting != -1)
1294                 return 3;
1295 
1296         /* If nothing is available, then don't bind to this device. */
1297         return -1;
1298 }
1299 
1300 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1301 {
1302         int r, alts;
1303 
1304         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1305                 return -EINVAL;
1306 
1307         alts = usblp->protocol[protocol].alt_setting;
1308         if (alts < 0)
1309                 return -EINVAL;
1310         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1311         if (r < 0) {
1312                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1313                         alts, usblp->ifnum);
1314                 return r;
1315         }
1316 
1317         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1318         usblp->current_protocol = protocol;
1319         dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1320                 usblp->minor, protocol);
1321         return 0;
1322 }
1323 
1324 /* Retrieves and caches device ID string.
1325  * Returns length, including length bytes but not null terminator.
1326  * On error, returns a negative errno value. */
1327 static int usblp_cache_device_id_string(struct usblp *usblp)
1328 {
1329         int err, length;
1330 
1331         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1332         if (err < 0) {
1333                 dev_dbg(&usblp->intf->dev,
1334                         "usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1335                         usblp->minor, err);
1336                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1337                 return -EIO;
1338         }
1339 
1340         /* First two bytes are length in big-endian.
1341          * They count themselves, and we copy them into
1342          * the user's buffer. */
1343         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1344         if (length < 2)
1345                 length = 2;
1346         else if (length >= USBLP_DEVICE_ID_SIZE)
1347                 length = USBLP_DEVICE_ID_SIZE - 1;
1348         usblp->device_id_string[length] = '\0';
1349 
1350         dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1351                 usblp->minor, length, &usblp->device_id_string[2]);
1352 
1353         return length;
1354 }
1355 
1356 static void usblp_disconnect(struct usb_interface *intf)
1357 {
1358         struct usblp *usblp = usb_get_intfdata(intf);
1359 
1360         usb_deregister_dev(intf, &usblp_class);
1361 
1362         if (!usblp || !usblp->dev) {
1363                 dev_err(&intf->dev, "bogus disconnect\n");
1364                 BUG();
1365         }
1366 
1367         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1368 
1369         mutex_lock(&usblp_mutex);
1370         mutex_lock(&usblp->mut);
1371         usblp->present = 0;
1372         wake_up(&usblp->wwait);
1373         wake_up(&usblp->rwait);
1374         usb_set_intfdata(intf, NULL);
1375 
1376         usblp_unlink_urbs(usblp);
1377         mutex_unlock(&usblp->mut);
1378 
1379         if (!usblp->used)
1380                 usblp_cleanup(usblp);
1381         mutex_unlock(&usblp_mutex);
1382 }
1383 
1384 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1385 {
1386         struct usblp *usblp = usb_get_intfdata(intf);
1387 
1388         usblp_unlink_urbs(usblp);
1389 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1390         /* not strictly necessary, but just in case */
1391         wake_up(&usblp->wwait);
1392         wake_up(&usblp->rwait);
1393 #endif
1394 
1395         return 0;
1396 }
1397 
1398 static int usblp_resume(struct usb_interface *intf)
1399 {
1400         struct usblp *usblp = usb_get_intfdata(intf);
1401         int r;
1402 
1403         r = handle_bidir(usblp);
1404 
1405         return r;
1406 }
1407 
1408 static const struct usb_device_id usblp_ids[] = {
1409         { USB_DEVICE_INFO(7, 1, 1) },
1410         { USB_DEVICE_INFO(7, 1, 2) },
1411         { USB_DEVICE_INFO(7, 1, 3) },
1412         { USB_INTERFACE_INFO(7, 1, 1) },
1413         { USB_INTERFACE_INFO(7, 1, 2) },
1414         { USB_INTERFACE_INFO(7, 1, 3) },
1415         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1416         { }                                             /* Terminating entry */
1417 };
1418 
1419 MODULE_DEVICE_TABLE(usb, usblp_ids);
1420 
1421 static struct usb_driver usblp_driver = {
1422         .name =         "usblp",
1423         .probe =        usblp_probe,
1424         .disconnect =   usblp_disconnect,
1425         .suspend =      usblp_suspend,
1426         .resume =       usblp_resume,
1427         .id_table =     usblp_ids,
1428         .supports_autosuspend = 1,
1429 };
1430 
1431 module_usb_driver(usblp_driver);
1432 
1433 MODULE_AUTHOR(DRIVER_AUTHOR);
1434 MODULE_DESCRIPTION(DRIVER_DESC);
1435 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1436 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1437 MODULE_LICENSE("GPL");
1438 

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