drivers/usb/class/usblp.c

   1 /*
   2  * usblp.c  Version 0.13
   3  *
   4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
   5  * Copyright (c) 1999 Pavel Machek      <pavel@suse.cz>
   6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
   7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
   8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
   9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
  10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
  11  *
  12  * USB Printer Device Class driver for USB printers and printer cables
  13  *
  14  * Sponsored by SuSE
  15  *
  16  * ChangeLog:
  17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
  18  *      v0.2 - some more cleanups
  19  *      v0.3 - cleaner again, waitqueue fixes
  20  *      v0.4 - fixes in unidirectional mode
  21  *      v0.5 - add DEVICE_ID string support
  22  *      v0.6 - never time out
  23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
  24  *      v0.8 - add devfs support
  25  *      v0.9 - fix unplug-while-open paths
  26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
  27  *      v0.11 - add proto_bias option (Pete Zaitcev)
  28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
  29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
  30  *              use usb_buffer_alloc() for read buf & write buf;
  31  */
  32
  33 /*
  34  * This program is free software; you can redistribute it and/or modify
  35  * it under the terms of the GNU General Public License as published by
  36  * the Free Software Foundation; either version 2 of the License, or
  37  * (at your option) any later version.
  38  *
  39  * This program is distributed in the hope that it will be useful,
  40  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  41  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  42  * GNU General Public License for more details.
  43  *
  44  * You should have received a copy of the GNU General Public License
  45  * along with this program; if not, write to the Free Software
  46  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  47  */
  48
  49 #include <linux/module.h>
  50 #include <linux/kernel.h>
  51 #include <linux/sched.h>
  52 #include <linux/smp_lock.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_VERSION "v0.13"
  66 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
  67 #define DRIVER_DESC "USB Printer Device Class driver"
  68
  69 #define USBLP_BUF_SIZE          8192
  70 #define USBLP_DEVICE_ID_SIZE    1024
  71
  72 /* ioctls: */
  73 #define LPGETSTATUS             0x060b          /* same as in drivers/char/lp.c */
  74 #define IOCNR_GET_DEVICE_ID             1
  75 #define IOCNR_GET_PROTOCOLS             2
  76 #define IOCNR_SET_PROTOCOL              3
  77 #define IOCNR_HP_SET_CHANNEL            4
  78 #define IOCNR_GET_BUS_ADDRESS           5
  79 #define IOCNR_GET_VID_PID               6
  80 #define IOCNR_SOFT_RESET                7
  81 /* Get device_id string: */
  82 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
  83 /* The following ioctls were added for http://hpoj.sourceforge.net: */
  84 /* Get two-int array:
  85  * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
  86  * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
  87 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
  88 /* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
  89 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
  90 /* Set channel number (HP Vendor-specific command): */
  91 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
  92 /* Get two-int array: [0]=bus number, [1]=device address: */
  93 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
  94 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
  95 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
  96 /* Perform class specific soft reset */
  97 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
  98
  99 /*
 100  * A DEVICE_ID string may include the printer's serial number.
 101  * It should end with a semi-colon (';').
 102  * An example from an HP 970C DeskJet printer is (this is one long string,
 103  * with the serial number changed):
 104 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:                    ;
 105  */
 106
 107 /*
 108  * USB Printer Requests
 109  */
 110
 111 #define USBLP_REQ_GET_ID                        0x00
 112 #define USBLP_REQ_GET_STATUS                    0x01
 113 #define USBLP_REQ_RESET                         0x02
 114 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
 115
 116 #define USBLP_MINORS            16
 117 #define USBLP_MINOR_BASE        0
 118
 119 #define USBLP_WRITE_TIMEOUT     (5000)                  /* 5 seconds */
 120
 121 #define USBLP_FIRST_PROTOCOL    1
 122 #define USBLP_LAST_PROTOCOL     3
 123 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
 124
 125 /*
 126  * some arbitrary status buffer size;
 127  * need a status buffer that is allocated via kmalloc(), not on stack
 128  */
 129 #define STATUS_BUF_SIZE         8
 130
 131 struct usblp {
 132         struct usb_device       *dev;                   /* USB device */
 133         struct mutex            mut;                    /* locks this struct, especially "dev" */
 134         char                    *writebuf;              /* write transfer_buffer */
 135         char                    *readbuf;               /* read transfer_buffer */
 136         char                    *statusbuf;             /* status transfer_buffer */
 137         struct urb              *readurb, *writeurb;    /* The urbs */
 138         wait_queue_head_t       wait;                   /* Zzzzz ... */
 139         int                     readcount;              /* Counter for reads */
 140         int                     ifnum;                  /* Interface number */
 141         struct usb_interface    *intf;                  /* The interface */
 142         /* Alternate-setting numbers and endpoints for each protocol
 143          * (7/1/{index=1,2,3}) that the device supports: */
 144         struct {
 145                 int                             alt_setting;
 146                 struct usb_endpoint_descriptor  *epwrite;
 147                 struct usb_endpoint_descriptor  *epread;
 148         }                       protocol[USBLP_MAX_PROTOCOLS];
 149         int                     current_protocol;
 150         int                     minor;                  /* minor number of device */
 151         int                     wcomplete;              /* writing is completed */
 152         int                     rcomplete;              /* reading is completed */
 153         unsigned int            quirks;                 /* quirks flags */
 154         unsigned char           used;                   /* True if open */
 155         unsigned char           present;                /* True if not disconnected */
 156         unsigned char           bidir;                  /* interface is bidirectional */
 157         unsigned char           sleeping;               /* interface is suspended */
 158         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
 159                                                         /* first 2 bytes are (big-endian) length */
 160 };
 161
 162 #ifdef DEBUG
 163 static void usblp_dump(struct usblp *usblp) {
 164         int p;
 165
 166         dbg("usblp=0x%p", usblp);
 167         dbg("dev=0x%p", usblp->dev);
 168         dbg("present=%d", usblp->present);
 169         dbg("readbuf=0x%p", usblp->readbuf);
 170         dbg("writebuf=0x%p", usblp->writebuf);
 171         dbg("readurb=0x%p", usblp->readurb);
 172         dbg("writeurb=0x%p", usblp->writeurb);
 173         dbg("readcount=%d", usblp->readcount);
 174         dbg("ifnum=%d", usblp->ifnum);
 175     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
 176         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
 177         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
 178         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
 179     }
 180         dbg("current_protocol=%d", usblp->current_protocol);
 181         dbg("minor=%d", usblp->minor);
 182         dbg("wcomplete=%d", usblp->wcomplete);
 183         dbg("rcomplete=%d", usblp->rcomplete);
 184         dbg("quirks=%d", usblp->quirks);
 185         dbg("used=%d", usblp->used);
 186         dbg("bidir=%d", usblp->bidir);
 187         dbg("sleeping=%d", usblp->sleeping);
 188         dbg("device_id_string=\"%s\"",
 189                 usblp->device_id_string ?
 190                         usblp->device_id_string + 2 :
 191                         (unsigned char *)"(null)");
 192 }
 193 #endif
 194
 195 /* Quirks: various printer quirks are handled by this table & its flags. */
 196
 197 struct quirk_printer_struct {
 198         __u16 vendorId;
 199         __u16 productId;
 200         unsigned int quirks;
 201 };
 202
 203 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
 204 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
 205 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
 206
 207 static const struct quirk_printer_struct quirk_printers[] = {
 208         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
 209         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
 210         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
 211         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
 212         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
 213         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
 214         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
 215         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
 216         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
 217         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
 218         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
 219         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
 220         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
 221         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
 222         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
 223         { 0, 0 }
 224 };
 225
 226 static int usblp_select_alts(struct usblp *usblp);
 227 static int usblp_set_protocol(struct usblp *usblp, int protocol);
 228 static int usblp_cache_device_id_string(struct usblp *usblp);
 229
 230 /* forward reference to make our lives easier */
 231 static struct usb_driver usblp_driver;
 232 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 233
 234 /*
 235  * Functions for usblp control messages.
 236  */
 237
 238 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
 239 {
 240         int retval;
 241         int index = usblp->ifnum;
 242
 243         /* High byte has the interface index.
 244            Low byte has the alternate setting.
 245          */
 246         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
 247           index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
 248         }
 249
 250         retval = usb_control_msg(usblp->dev,
 251                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
 252                 request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
 253         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
 254                 request, !!dir, recip, value, index, len, retval);
 255         return retval < 0 ? retval : 0;
 256 }
 257
 258 #define usblp_read_status(usblp, status)\
 259         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
 260 #define usblp_get_id(usblp, config, id, maxlen)\
 261         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
 262 #define usblp_reset(usblp)\
 263         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
 264
 265 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
 266         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
 267
 268 /*
 269  * See the description for usblp_select_alts() below for the usage
 270  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
 271  * case of any trouble.
 272  */
 273 static int proto_bias = -1;
 274
 275 /*
 276  * URB callback.
 277  */
 278
 279 static void usblp_bulk_read(struct urb *urb)
 280 {
 281         struct usblp *usblp = urb->context;
 282
 283         if (unlikely(!usblp || !usblp->dev || !usblp->used))
 284                 return;
 285
 286         if (unlikely(!usblp->present))
 287                 goto unplug;
 288         if (unlikely(urb->status))
 289                 warn("usblp%d: nonzero read/write bulk status received: %d",
 290                         usblp->minor, urb->status);
 291         usblp->rcomplete = 1;
 292 unplug:
 293         wake_up_interruptible(&usblp->wait);
 294 }
 295
 296 static void usblp_bulk_write(struct urb *urb)
 297 {
 298         struct usblp *usblp = urb->context;
 299
 300         if (unlikely(!usblp || !usblp->dev || !usblp->used))
 301                 return;
 302         if (unlikely(!usblp->present))
 303                 goto unplug;
 304         if (unlikely(urb->status))
 305                 warn("usblp%d: nonzero read/write bulk status received: %d",
 306                         usblp->minor, urb->status);
 307         usblp->wcomplete = 1;
 308 unplug:
 309         wake_up_interruptible(&usblp->wait);
 310 }
 311
 312 /*
 313  * Get and print printer errors.
 314  */
 315
 316 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
 317
 318 static int usblp_check_status(struct usblp *usblp, int err)
 319 {
 320         unsigned char status, newerr = 0;
 321         int error;
 322
 323         error = usblp_read_status (usblp, usblp->statusbuf);
 324         if (error < 0) {
 325                 if (printk_ratelimit())
 326                         err("usblp%d: error %d reading printer status",
 327                                 usblp->minor, error);
 328                 return 0;
 329         }
 330
 331         status = *usblp->statusbuf;
 332
 333         if (~status & LP_PERRORP)
 334                 newerr = 3;
 335         if (status & LP_POUTPA)
 336                 newerr = 1;
 337         if (~status & LP_PSELECD)
 338                 newerr = 2;
 339
 340         if (newerr != err)
 341                 info("usblp%d: %s", usblp->minor, usblp_messages[newerr]);
 342
 343         return newerr;
 344 }
 345
 346 static int handle_bidir (struct usblp *usblp)
 347 {
 348         if (usblp->bidir && usblp->used && !usblp->sleeping) {
 349                 usblp->readcount = 0;
 350                 usblp->readurb->dev = usblp->dev;
 351                 if (usb_submit_urb(usblp->readurb, GFP_KERNEL) < 0) {
 352                         usblp->used = 0;
 353                         return -EIO;
 354                 }
 355         }
 356
 357         return 0;
 358 }
 359
 360 /*
 361  * File op functions.
 362  */
 363
 364 static int usblp_open(struct inode *inode, struct file *file)
 365 {
 366         int minor = iminor(inode);
 367         struct usblp *usblp;
 368         struct usb_interface *intf;
 369         int retval;
 370
 371         if (minor < 0)
 372                 return -ENODEV;
 373
 374         mutex_lock (&usblp_mutex);
 375
 376         retval = -ENODEV;
 377         intf = usb_find_interface(&usblp_driver, minor);
 378         if (!intf) {
 379                 goto out;
 380         }
 381         usblp = usb_get_intfdata (intf);
 382         if (!usblp || !usblp->dev || !usblp->present)
 383                 goto out;
 384
 385         retval = -EBUSY;
 386         if (usblp->used)
 387                 goto out;
 388
 389         /*
 390          * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
 391          * This is #if 0-ed because we *don't* want to fail an open
 392          * just because the printer is off-line.
 393          */
 394 #if 0
 395         if ((retval = usblp_check_status(usblp, 0))) {
 396                 retval = retval > 1 ? -EIO : -ENOSPC;
 397                 goto out;
 398         }
 399 #else
 400         retval = 0;
 401 #endif
 402
 403         retval = usb_autopm_get_interface(intf);
 404         if (retval < 0)
 405                 goto out;
 406         usblp->used = 1;
 407         file->private_data = usblp;
 408
 409         usblp->writeurb->transfer_buffer_length = 0;
 410         usblp->wcomplete = 1; /* we begin writeable */
 411         usblp->rcomplete = 0;
 412         usblp->writeurb->status = 0;
 413         usblp->readurb->status = 0;
 414
 415         if (handle_bidir(usblp) < 0) {
 416                 file->private_data = NULL;
 417                 retval = -EIO;
 418         }
 419 out:
 420         mutex_unlock (&usblp_mutex);
 421         return retval;
 422 }
 423
 424 static void usblp_cleanup (struct usblp *usblp)
 425 {
 426         info("usblp%d: removed", usblp->minor);
 427
 428         kfree (usblp->device_id_string);
 429         kfree (usblp->statusbuf);
 430         usb_free_urb(usblp->writeurb);
 431         usb_free_urb(usblp->readurb);
 432         kfree (usblp);
 433 }
 434
 435 static void usblp_unlink_urbs(struct usblp *usblp)
 436 {
 437         usb_kill_urb(usblp->writeurb);
 438         if (usblp->bidir)
 439                 usb_kill_urb(usblp->readurb);
 440 }
 441
 442 static int usblp_release(struct inode *inode, struct file *file)
 443 {
 444         struct usblp *usblp = file->private_data;
 445
 446         mutex_lock (&usblp_mutex);
 447         usblp->used = 0;
 448         if (usblp->present) {
 449                 usblp_unlink_urbs(usblp);
 450                 usb_autopm_put_interface(usblp->intf);
 451         } else          /* finish cleanup from disconnect */
 452                 usblp_cleanup (usblp);
 453         mutex_unlock (&usblp_mutex);
 454         return 0;
 455 }
 456
 457 /* No kernel lock - fine */
 458 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
 459 {
 460         struct usblp *usblp = file->private_data;
 461         poll_wait(file, &usblp->wait, wait);
 462         return ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
 463                                | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
 464 }
 465
 466 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 467 {
 468         struct usblp *usblp = file->private_data;
 469         int length, err, i;
 470         unsigned char newChannel;
 471         int status;
 472         int twoints[2];
 473         int retval = 0;
 474
 475         mutex_lock (&usblp->mut);
 476         if (!usblp->present) {
 477                 retval = -ENODEV;
 478                 goto done;
 479         }
 480
 481         if (usblp->sleeping) {
 482                 retval = -ENODEV;
 483                 goto done;
 484         }
 485
 486         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
 487                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
 488
 489         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 490
 491                 switch (_IOC_NR(cmd)) {
 492
 493                         case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 494                                 if (_IOC_DIR(cmd) != _IOC_READ) {
 495                                         retval = -EINVAL;
 496                                         goto done;
 497                                 }
 498
 499                                 length = usblp_cache_device_id_string(usblp);
 500                                 if (length < 0) {
 501                                         retval = length;
 502                                         goto done;
 503                                 }
 504                                 if (length > _IOC_SIZE(cmd))
 505                                         length = _IOC_SIZE(cmd); /* truncate */
 506
 507                                 if (copy_to_user((void __user *) arg,
 508                                                 usblp->device_id_string,
 509                                                 (unsigned long) length)) {
 510                                         retval = -EFAULT;
 511                                         goto done;
 512                                 }
 513
 514                                 break;
 515
 516                         case IOCNR_GET_PROTOCOLS:
 517                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 518                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 519                                         retval = -EINVAL;
 520                                         goto done;
 521                                 }
 522
 523                                 twoints[0] = usblp->current_protocol;
 524                                 twoints[1] = 0;
 525                                 for (i = USBLP_FIRST_PROTOCOL;
 526                                      i <= USBLP_LAST_PROTOCOL; i++) {
 527                                         if (usblp->protocol[i].alt_setting >= 0)
 528                                                 twoints[1] |= (1<<i);
 529                                 }
 530
 531                                 if (copy_to_user((void __user *)arg,
 532                                                 (unsigned char *)twoints,
 533                                                 sizeof(twoints))) {
 534                                         retval = -EFAULT;
 535                                         goto done;
 536                                 }
 537
 538                                 break;
 539
 540                         case IOCNR_SET_PROTOCOL:
 541                                 if (_IOC_DIR(cmd) != _IOC_WRITE) {
 542                                         retval = -EINVAL;
 543                                         goto done;
 544                                 }
 545
 546 #ifdef DEBUG
 547                                 if (arg == -10) {
 548                                         usblp_dump(usblp);
 549                                         break;
 550                                 }
 551 #endif
 552
 553                                 usblp_unlink_urbs(usblp);
 554                                 retval = usblp_set_protocol(usblp, arg);
 555                                 if (retval < 0) {
 556                                         usblp_set_protocol(usblp,
 557                                                 usblp->current_protocol);
 558                                 }
 559                                 break;
 560
 561                         case IOCNR_HP_SET_CHANNEL:
 562                                 if (_IOC_DIR(cmd) != _IOC_WRITE ||
 563                                     le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 564                                     usblp->quirks & USBLP_QUIRK_BIDIR) {
 565                                         retval = -EINVAL;
 566                                         goto done;
 567                                 }
 568
 569                                 err = usblp_hp_channel_change_request(usblp,
 570                                         arg, &newChannel);
 571                                 if (err < 0) {
 572                                         err("usblp%d: error = %d setting "
 573                                                 "HP channel",
 574                                                 usblp->minor, err);
 575                                         retval = -EIO;
 576                                         goto done;
 577                                 }
 578
 579                                 dbg("usblp%d requested/got HP channel %ld/%d",
 580                                         usblp->minor, arg, newChannel);
 581                                 break;
 582
 583                         case IOCNR_GET_BUS_ADDRESS:
 584                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 585                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 586                                         retval = -EINVAL;
 587                                         goto done;
 588                                 }
 589
 590                                 twoints[0] = usblp->dev->bus->busnum;
 591                                 twoints[1] = usblp->dev->devnum;
 592                                 if (copy_to_user((void __user *)arg,
 593                                                 (unsigned char *)twoints,
 594                                                 sizeof(twoints))) {
 595                                         retval = -EFAULT;
 596                                         goto done;
 597                                 }
 598
 599                                 dbg("usblp%d is bus=%d, device=%d",
 600                                         usblp->minor, twoints[0], twoints[1]);
 601                                 break;
 602
 603                         case IOCNR_GET_VID_PID:
 604                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 605                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 606                                         retval = -EINVAL;
 607                                         goto done;
 608                                 }
 609
 610                                 twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 611                                 twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 612                                 if (copy_to_user((void __user *)arg,
 613                                                 (unsigned char *)twoints,
 614                                                 sizeof(twoints))) {
 615                                         retval = -EFAULT;
 616                                         goto done;
 617                                 }
 618
 619                                 dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
 620                                         usblp->minor, twoints[0], twoints[1]);
 621                                 break;
 622
 623                         case IOCNR_SOFT_RESET:
 624                                 if (_IOC_DIR(cmd) != _IOC_NONE) {
 625                                         retval = -EINVAL;
 626                                         goto done;
 627                                 }
 628                                 retval = usblp_reset(usblp);
 629                                 break;
 630                         default:
 631                                 retval = -ENOTTY;
 632                 }
 633         else    /* old-style ioctl value */
 634                 switch (cmd) {
 635
 636                         case LPGETSTATUS:
 637                                 if (usblp_read_status(usblp, usblp->statusbuf)) {
 638                                         if (printk_ratelimit())
 639                                                 err("usblp%d: failed reading printer status",
 640                                                         usblp->minor);
 641                                         retval = -EIO;
 642                                         goto done;
 643                                 }
 644                                 status = *usblp->statusbuf;
 645                                 if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
 646                                         retval = -EFAULT;
 647                                 break;
 648
 649                         default:
 650                                 retval = -ENOTTY;
 651                 }
 652
 653 done:
 654         mutex_unlock (&usblp->mut);
 655         return retval;
 656 }
 657
 658 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 659 {
 660         struct usblp *usblp = file->private_data;
 661         int timeout, intr, rv, err = 0, transfer_length = 0;
 662         size_t writecount = 0;
 663
 664         while (writecount < count) {
 665                 if (!usblp->wcomplete) {
 666                         barrier();
 667                         if (file->f_flags & O_NONBLOCK) {
 668                                 writecount += transfer_length;
 669                                 return writecount ? writecount : -EAGAIN;
 670                         }
 671
 672                         timeout = USBLP_WRITE_TIMEOUT;
 673
 674                         rv = wait_event_interruptible_timeout(usblp->wait, usblp->wcomplete || !usblp->present , timeout);
 675                         if (rv < 0)
 676                                 return writecount ? writecount : -EINTR;
 677                 }
 678                 intr = mutex_lock_interruptible (&usblp->mut);
 679                 if (intr)
 680                         return writecount ? writecount : -EINTR;
 681                 if (!usblp->present) {
 682                         mutex_unlock (&usblp->mut);
 683                         return -ENODEV;
 684                 }
 685
 686                 if (usblp->sleeping) {
 687                         mutex_unlock (&usblp->mut);
 688                         return writecount ? writecount : -ENODEV;
 689                 }
 690
 691                 if (usblp->writeurb->status != 0) {
 692                         if (usblp->quirks & USBLP_QUIRK_BIDIR) {
 693                                 if (!usblp->wcomplete)
 694                                         err("usblp%d: error %d writing to printer",
 695                                                 usblp->minor, usblp->writeurb->status);
 696                                 err = usblp->writeurb->status;
 697                         } else
 698                                 err = usblp_check_status(usblp, err);
 699                         mutex_unlock (&usblp->mut);
 700
 701                         /* if the fault was due to disconnect, let khubd's
 702                          * call to usblp_disconnect() grab usblp->mut ...
 703                          */
 704                         schedule ();
 705                         continue;
 706                 }
 707
 708                 /* We must increment writecount here, and not at the
 709                  * end of the loop. Otherwise, the final loop iteration may
 710                  * be skipped, leading to incomplete printer output.
 711                  */
 712                 writecount += transfer_length;
 713                 if (writecount == count) {
 714                         mutex_unlock(&usblp->mut);
 715                         break;
 716                 }
 717
 718                 transfer_length=(count - writecount);
 719                 if (transfer_length > USBLP_BUF_SIZE)
 720                         transfer_length = USBLP_BUF_SIZE;
 721
 722                 usblp->writeurb->transfer_buffer_length = transfer_length;
 723
 724                 if (copy_from_user(usblp->writeurb->transfer_buffer,
 725                                    buffer + writecount, transfer_length)) {
 726                         mutex_unlock(&usblp->mut);
 727                         return writecount ? writecount : -EFAULT;
 728                 }
 729
 730                 usblp->writeurb->dev = usblp->dev;
 731                 usblp->wcomplete = 0;
 732                 err = usb_submit_urb(usblp->writeurb, GFP_KERNEL);
 733                 if (err) {
 734                         usblp->wcomplete = 1;
 735                         if (err != -ENOMEM)
 736                                 count = -EIO;
 737                         else
 738                                 count = writecount ? writecount : -ENOMEM;
 739                         mutex_unlock (&usblp->mut);
 740                         break;
 741                 }
 742                 mutex_unlock (&usblp->mut);
 743         }
 744
 745         return count;
 746 }
 747
 748 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 749 {
 750         struct usblp *usblp = file->private_data;
 751         int rv, intr;
 752
 753         if (!usblp->bidir)
 754                 return -EINVAL;
 755
 756         intr = mutex_lock_interruptible (&usblp->mut);
 757         if (intr)
 758                 return -EINTR;
 759         if (!usblp->present) {
 760                 count = -ENODEV;
 761                 goto done;
 762         }
 763
 764         if (!usblp->rcomplete) {
 765                 barrier();
 766
 767                 if (file->f_flags & O_NONBLOCK) {
 768                         count = -EAGAIN;
 769                         goto done;
 770                 }
 771                 mutex_unlock(&usblp->mut);
 772                 rv = wait_event_interruptible(usblp->wait, usblp->rcomplete || !usblp->present);
 773                 mutex_lock(&usblp->mut);
 774                 if (rv < 0) {
 775                         count = -EINTR;
 776                         goto done;
 777                 }
 778         }
 779
 780         if (!usblp->present) {
 781                 count = -ENODEV;
 782                 goto done;
 783         }
 784
 785         if (usblp->sleeping) {
 786                 count = -ENODEV;
 787                 goto done;
 788         }
 789
 790         if (usblp->readurb->status) {
 791                 err("usblp%d: error %d reading from printer",
 792                         usblp->minor, usblp->readurb->status);
 793                 usblp->readurb->dev = usblp->dev;
 794                 usblp->readcount = 0;
 795                 usblp->rcomplete = 0;
 796                 if (usb_submit_urb(usblp->readurb, GFP_KERNEL) < 0)
 797                         dbg("error submitting urb");
 798                 count = -EIO;
 799                 goto done;
 800         }
 801
 802         count = count < usblp->readurb->actual_length - usblp->readcount ?
 803                 count : usblp->readurb->actual_length - usblp->readcount;
 804
 805         if (copy_to_user(buffer, usblp->readurb->transfer_buffer + usblp->readcount, count)) {
 806                 count = -EFAULT;
 807                 goto done;
 808         }
 809
 810         if ((usblp->readcount += count) == usblp->readurb->actual_length) {
 811                 usblp->readcount = 0;
 812                 usblp->readurb->dev = usblp->dev;
 813                 usblp->rcomplete = 0;
 814                 if (usb_submit_urb(usblp->readurb, GFP_KERNEL)) {
 815                         count = -EIO;
 816                         goto done;
 817                 }
 818         }
 819
 820 done:
 821         mutex_unlock (&usblp->mut);
 822         return count;
 823 }
 824
 825 /*
 826  * Checks for printers that have quirks, such as requiring unidirectional
 827  * communication but reporting bidirectional; currently some HP printers
 828  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
 829  * sent at each open (like some Epsons).
 830  * Returns 1 if found, 0 if not found.
 831  *
 832  * HP recommended that we use the bidirectional interface but
 833  * don't attempt any bulk IN transfers from the IN endpoint.
 834  * Here's some more detail on the problem:
 835  * The problem is not that it isn't bidirectional though. The problem
 836  * is that if you request a device ID, or status information, while
 837  * the buffers are full, the return data will end up in the print data
 838  * buffer. For example if you make sure you never request the device ID
 839  * while you are sending print data, and you don't try to query the
 840  * printer status every couple of milliseconds, you will probably be OK.
 841  */
 842 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
 843 {
 844         int i;
 845
 846         for (i = 0; quirk_printers[i].vendorId; i++) {
 847                 if (vendor == quirk_printers[i].vendorId &&
 848                     product == quirk_printers[i].productId)
 849                         return quirk_printers[i].quirks;
 850         }
 851         return 0;
 852 }
 853
 854 static const struct file_operations usblp_fops = {
 855         .owner =        THIS_MODULE,
 856         .read =         usblp_read,
 857         .write =        usblp_write,
 858         .poll =         usblp_poll,
 859         .unlocked_ioctl =       usblp_ioctl,
 860         .compat_ioctl =         usblp_ioctl,
 861         .open =         usblp_open,
 862         .release =      usblp_release,
 863 };
 864
 865 static struct usb_class_driver usblp_class = {
 866         .name =         "lp%d",
 867         .fops =         &usblp_fops,
 868         .minor_base =   USBLP_MINOR_BASE,
 869 };
 870
 871 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
 872 {
 873         struct usb_interface *intf = to_usb_interface(dev);
 874         struct usblp *usblp = usb_get_intfdata (intf);
 875
 876         if (usblp->device_id_string[0] == 0 &&
 877             usblp->device_id_string[1] == 0)
 878                 return 0;
 879
 880         return sprintf(buf, "%s", usblp->device_id_string+2);
 881 }
 882
 883 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
 884
 885 static int usblp_probe(struct usb_interface *intf,
 886                        const struct usb_device_id *id)
 887 {
 888         struct usb_device *dev = interface_to_usbdev (intf);
 889         struct usblp *usblp = NULL;
 890         int protocol;
 891         int retval;
 892
 893         /* Malloc and start initializing usblp structure so we can use it
 894          * directly. */
 895         if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
 896                 err("out of memory for usblp");
 897                 goto abort;
 898         }
 899         usblp->dev = dev;
 900         mutex_init (&usblp->mut);
 901         init_waitqueue_head(&usblp->wait);
 902         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
 903         usblp->intf = intf;
 904
 905         usblp->writeurb = usb_alloc_urb(0, GFP_KERNEL);
 906         if (!usblp->writeurb) {
 907                 err("out of memory");
 908                 goto abort;
 909         }
 910         usblp->readurb = usb_alloc_urb(0, GFP_KERNEL);
 911         if (!usblp->readurb) {
 912                 err("out of memory");
 913                 goto abort;
 914         }
 915
 916         /* Malloc device ID string buffer to the largest expected length,
 917          * since we can re-query it on an ioctl and a dynamic string
 918          * could change in length. */
 919         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
 920                 err("out of memory for device_id_string");
 921                 goto abort;
 922         }
 923
 924         usblp->writebuf = usblp->readbuf = NULL;
 925         usblp->writeurb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 926         usblp->readurb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 927         /* Malloc write & read buffers.  We somewhat wastefully
 928          * malloc both regardless of bidirectionality, because the
 929          * alternate setting can be changed later via an ioctl. */
 930         if (!(usblp->writebuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
 931                                 GFP_KERNEL, &usblp->writeurb->transfer_dma))) {
 932                 err("out of memory for write buf");
 933                 goto abort;
 934         }
 935         if (!(usblp->readbuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
 936                                 GFP_KERNEL, &usblp->readurb->transfer_dma))) {
 937                 err("out of memory for read buf");
 938                 goto abort;
 939         }
 940
 941         /* Allocate buffer for printer status */
 942         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
 943         if (!usblp->statusbuf) {
 944                 err("out of memory for statusbuf");
 945                 goto abort;
 946         }
 947
 948         /* Lookup quirks for this printer. */
 949         usblp->quirks = usblp_quirks(
 950                 le16_to_cpu(dev->descriptor.idVendor),
 951                 le16_to_cpu(dev->descriptor.idProduct));
 952
 953         /* Analyze and pick initial alternate settings and endpoints. */
 954         protocol = usblp_select_alts(usblp);
 955         if (protocol < 0) {
 956                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
 957                         le16_to_cpu(dev->descriptor.idVendor),
 958                         le16_to_cpu(dev->descriptor.idProduct));
 959                 goto abort;
 960         }
 961
 962         /* Setup the selected alternate setting and endpoints. */
 963         if (usblp_set_protocol(usblp, protocol) < 0)
 964                 goto abort;
 965
 966         /* Retrieve and store the device ID string. */
 967         usblp_cache_device_id_string(usblp);
 968         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
 969         if (retval)
 970                 goto abort_intfdata;
 971
 972 #ifdef DEBUG
 973         usblp_check_status(usblp, 0);
 974 #endif
 975
 976         usb_set_intfdata (intf, usblp);
 977
 978         usblp->present = 1;
 979
 980         retval = usb_register_dev(intf, &usblp_class);
 981         if (retval) {
 982                 err("Not able to get a minor for this device.");
 983                 goto abort_intfdata;
 984         }
 985         usblp->minor = intf->minor;
 986         info("usblp%d: USB %sdirectional printer dev %d "
 987                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X",
 988                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
 989                 usblp->ifnum,
 990                 usblp->protocol[usblp->current_protocol].alt_setting,
 991                 usblp->current_protocol,
 992                 le16_to_cpu(usblp->dev->descriptor.idVendor),
 993                 le16_to_cpu(usblp->dev->descriptor.idProduct));
 994
 995         return 0;
 996
 997 abort_intfdata:
 998         usb_set_intfdata (intf, NULL);
 999         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1000 abort:
1001         if (usblp) {
1002                 if (usblp->writebuf)
1003                         usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
1004                                 usblp->writebuf, usblp->writeurb->transfer_dma);
1005                 if (usblp->readbuf)
1006                         usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
1007                                 usblp->readbuf, usblp->writeurb->transfer_dma);
1008                 kfree(usblp->statusbuf);
1009                 kfree(usblp->device_id_string);
1010                 usb_free_urb(usblp->writeurb);
1011                 usb_free_urb(usblp->readurb);
1012                 kfree(usblp);
1013         }
1014         return -EIO;
1015 }
1016
1017 /*
1018  * We are a "new" style driver with usb_device_id table,
1019  * but our requirements are too intricate for simple match to handle.
1020  *
1021  * The "proto_bias" option may be used to specify the preferred protocol
1022  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1023  * supports the preferred protocol, then we bind to it.
1024  *
1025  * The best interface for us is 7/1/2, because it is compatible
1026  * with a stream of characters. If we find it, we bind to it.
1027  *
1028  * Note that the people from hpoj.sourceforge.net need to be able to
1029  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1030  *
1031  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1032  * stream-compatible, because this matches the behaviour of the old code.
1033  *
1034  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1035  */
1036 static int usblp_select_alts(struct usblp *usblp)
1037 {
1038         struct usb_interface *if_alt;
1039         struct usb_host_interface *ifd;
1040         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1041         int p, i, e;
1042
1043         if_alt = usblp->intf;
1044
1045         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1046                 usblp->protocol[p].alt_setting = -1;
1047
1048         /* Find out what we have. */
1049         for (i = 0; i < if_alt->num_altsetting; i++) {
1050                 ifd = &if_alt->altsetting[i];
1051
1052                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1053                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1054                                 continue;
1055
1056                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1057                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1058                         continue;
1059
1060                 /* Look for bulk OUT and IN endpoints. */
1061                 epwrite = epread = NULL;
1062                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1063                         epd = &ifd->endpoint[e].desc;
1064
1065                         if (usb_endpoint_is_bulk_out(epd))
1066                                 if (!epwrite)
1067                                         epwrite = epd;
1068
1069                         if (usb_endpoint_is_bulk_in(epd))
1070                                 if (!epread)
1071                                         epread = epd;
1072                 }
1073
1074                 /* Ignore buggy hardware without the right endpoints. */
1075                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1076                         continue;
1077
1078                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1079                  * and buggy bidirectional printers. */
1080                 if (ifd->desc.bInterfaceProtocol == 1) {
1081                         epread = NULL;
1082                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1083                         info("Disabling reads from problem bidirectional "
1084                                 "printer on usblp%d", usblp->minor);
1085                         epread = NULL;
1086                 }
1087
1088                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1089                                 ifd->desc.bAlternateSetting;
1090                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1091                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1092         }
1093
1094         /* If our requested protocol is supported, then use it. */
1095         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1096             proto_bias <= USBLP_LAST_PROTOCOL &&
1097             usblp->protocol[proto_bias].alt_setting != -1)
1098                 return proto_bias;
1099
1100         /* Ordering is important here. */
1101         if (usblp->protocol[2].alt_setting != -1)
1102                 return 2;
1103         if (usblp->protocol[1].alt_setting != -1)
1104                 return 1;
1105         if (usblp->protocol[3].alt_setting != -1)
1106                 return 3;
1107
1108         /* If nothing is available, then don't bind to this device. */
1109         return -1;
1110 }
1111
1112 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1113 {
1114         int r, alts;
1115
1116         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1117                 return -EINVAL;
1118
1119         alts = usblp->protocol[protocol].alt_setting;
1120         if (alts < 0)
1121                 return -EINVAL;
1122         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1123         if (r < 0) {
1124                 err("can't set desired altsetting %d on interface %d",
1125                         alts, usblp->ifnum);
1126                 return r;
1127         }
1128
1129         usb_fill_bulk_urb(usblp->writeurb, usblp->dev,
1130                 usb_sndbulkpipe(usblp->dev,
1131                   usblp->protocol[protocol].epwrite->bEndpointAddress),
1132                 usblp->writebuf, 0,
1133                 usblp_bulk_write, usblp);
1134
1135         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1136         if (usblp->bidir)
1137                 usb_fill_bulk_urb(usblp->readurb, usblp->dev,
1138                         usb_rcvbulkpipe(usblp->dev,
1139                           usblp->protocol[protocol].epread->bEndpointAddress),
1140                         usblp->readbuf, USBLP_BUF_SIZE,
1141                         usblp_bulk_read, usblp);
1142
1143         usblp->current_protocol = protocol;
1144         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1145         return 0;
1146 }
1147
1148 /* Retrieves and caches device ID string.
1149  * Returns length, including length bytes but not null terminator.
1150  * On error, returns a negative errno value. */
1151 static int usblp_cache_device_id_string(struct usblp *usblp)
1152 {
1153         int err, length;
1154
1155         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1156         if (err < 0) {
1157                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1158                         usblp->minor, err);
1159                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1160                 return -EIO;
1161         }
1162
1163         /* First two bytes are length in big-endian.
1164          * They count themselves, and we copy them into
1165          * the user's buffer. */
1166         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1167         if (length < 2)
1168                 length = 2;
1169         else if (length >= USBLP_DEVICE_ID_SIZE)
1170                 length = USBLP_DEVICE_ID_SIZE - 1;
1171         usblp->device_id_string[length] = '\0';
1172
1173         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1174                 usblp->minor, length, &usblp->device_id_string[2]);
1175
1176         return length;
1177 }
1178
1179 static void usblp_disconnect(struct usb_interface *intf)
1180 {
1181         struct usblp *usblp = usb_get_intfdata (intf);
1182
1183         usb_deregister_dev(intf, &usblp_class);
1184
1185         if (!usblp || !usblp->dev) {
1186                 err("bogus disconnect");
1187                 BUG ();
1188         }
1189
1190         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1191
1192         mutex_lock (&usblp_mutex);
1193         mutex_lock (&usblp->mut);
1194         usblp->present = 0;
1195         usb_set_intfdata (intf, NULL);
1196
1197         usblp_unlink_urbs(usblp);
1198         usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
1199                         usblp->writebuf, usblp->writeurb->transfer_dma);
1200         usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
1201                         usblp->readbuf, usblp->readurb->transfer_dma);
1202         mutex_unlock (&usblp->mut);
1203
1204         if (!usblp->used)
1205                 usblp_cleanup (usblp);
1206         mutex_unlock (&usblp_mutex);
1207 }
1208
1209 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1210 {
1211         struct usblp *usblp = usb_get_intfdata (intf);
1212
1213         /* we take no more IO */
1214         usblp->sleeping = 1;
1215         usblp_unlink_urbs(usblp);
1216
1217         return 0;
1218 }
1219
1220 static int usblp_resume (struct usb_interface *intf)
1221 {
1222         struct usblp *usblp = usb_get_intfdata (intf);
1223         int r;
1224
1225         usblp->sleeping = 0;
1226         r = handle_bidir (usblp);
1227
1228         return r;
1229 }
1230
1231 static struct usb_device_id usblp_ids [] = {
1232         { USB_DEVICE_INFO(7, 1, 1) },
1233         { USB_DEVICE_INFO(7, 1, 2) },
1234         { USB_DEVICE_INFO(7, 1, 3) },
1235         { USB_INTERFACE_INFO(7, 1, 1) },
1236         { USB_INTERFACE_INFO(7, 1, 2) },
1237         { USB_INTERFACE_INFO(7, 1, 3) },
1238         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1239         { }                                             /* Terminating entry */
1240 };
1241
1242 MODULE_DEVICE_TABLE (usb, usblp_ids);
1243
1244 static struct usb_driver usblp_driver = {
1245         .name =         "usblp",
1246         .probe =        usblp_probe,
1247         .disconnect =   usblp_disconnect,
1248         .suspend =      usblp_suspend,
1249         .resume =       usblp_resume,
1250         .id_table =     usblp_ids,
1251         .supports_autosuspend = 1,
1252 };
1253
1254 static int __init usblp_init(void)
1255 {
1256         int retval;
1257         retval = usb_register(&usblp_driver);
1258         if (!retval)
1259                 info(DRIVER_VERSION ": " DRIVER_DESC);
1260
1261         return retval;
1262 }
1263
1264 static void __exit usblp_exit(void)
1265 {
1266         usb_deregister(&usblp_driver);
1267 }
1268
1269 module_init(usblp_init);
1270 module_exit(usblp_exit);
1271
1272 MODULE_AUTHOR( DRIVER_AUTHOR );
1273 MODULE_DESCRIPTION( DRIVER_DESC );
1274 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1275 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1276 MODULE_LICENSE("GPL");