drivers/usb/class/usblp.c

   1 /*
   2  * usblp.c
   3  *
   4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
   5  * Copyright (c) 1999 Pavel Machek      <pavel@suse.cz>
   6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
   7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
   8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
   9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
  10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
  11  *
  12  * USB Printer Device Class driver for USB printers and printer cables
  13  *
  14  * Sponsored by SuSE
  15  *
  16  * ChangeLog:
  17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
  18  *      v0.2 - some more cleanups
  19  *      v0.3 - cleaner again, waitqueue fixes
  20  *      v0.4 - fixes in unidirectional mode
  21  *      v0.5 - add DEVICE_ID string support
  22  *      v0.6 - never time out
  23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
  24  *      v0.8 - add devfs support
  25  *      v0.9 - fix unplug-while-open paths
  26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
  27  *      v0.11 - add proto_bias option (Pete Zaitcev)
  28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
  29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
  30  *              use usb_buffer_alloc() for read buf & write buf;
  31  */
  32
  33 /*
  34  * This program is free software; you can redistribute it and/or modify
  35  * it under the terms of the GNU General Public License as published by
  36  * the Free Software Foundation; either version 2 of the License, or
  37  * (at your option) any later version.
  38  *
  39  * This program is distributed in the hope that it will be useful,
  40  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  41  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  42  * GNU General Public License for more details.
  43  *
  44  * You should have received a copy of the GNU General Public License
  45  * along with this program; if not, write to the Free Software
  46  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  47  */
  48
  49 #include <linux/module.h>
  50 #include <linux/kernel.h>
  51 #include <linux/sched.h>
  52 #include <linux/signal.h>
  53 #include <linux/poll.h>
  54 #include <linux/init.h>
  55 #include <linux/slab.h>
  56 #include <linux/lp.h>
  57 #include <linux/mutex.h>
  58 #undef DEBUG
  59 #include <linux/usb.h>
  60
  61 /*
  62  * Version Information
  63  */
  64 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
  65 #define DRIVER_DESC "USB Printer Device Class driver"
  66
  67 #define USBLP_BUF_SIZE          8192
  68 #define USBLP_BUF_SIZE_IN       1024
  69 #define USBLP_DEVICE_ID_SIZE    1024
  70
  71 /* ioctls: */
  72 #define IOCNR_GET_DEVICE_ID             1
  73 #define IOCNR_GET_PROTOCOLS             2
  74 #define IOCNR_SET_PROTOCOL              3
  75 #define IOCNR_HP_SET_CHANNEL            4
  76 #define IOCNR_GET_BUS_ADDRESS           5
  77 #define IOCNR_GET_VID_PID               6
  78 #define IOCNR_SOFT_RESET                7
  79 /* Get device_id string: */
  80 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
  81 /* The following ioctls were added for http://hpoj.sourceforge.net: */
  82 /* Get two-int array:
  83  * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
  84  * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
  85 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
  86 /* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
  87 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
  88 /* Set channel number (HP Vendor-specific command): */
  89 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
  90 /* Get two-int array: [0]=bus number, [1]=device address: */
  91 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
  92 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
  93 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
  94 /* Perform class specific soft reset */
  95 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
  96
  97 /*
  98  * A DEVICE_ID string may include the printer's serial number.
  99  * It should end with a semi-colon (';').
 100  * An example from an HP 970C DeskJet printer is (this is one long string,
 101  * with the serial number changed):
 102 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:                    ;
 103  */
 104
 105 /*
 106  * USB Printer Requests
 107  */
 108
 109 #define USBLP_REQ_GET_ID                        0x00
 110 #define USBLP_REQ_GET_STATUS                    0x01
 111 #define USBLP_REQ_RESET                         0x02
 112 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
 113
 114 #define USBLP_MINORS            16
 115 #define USBLP_MINOR_BASE        0
 116
 117 #define USBLP_WRITE_TIMEOUT     (5000)                  /* 5 seconds */
 118
 119 #define USBLP_FIRST_PROTOCOL    1
 120 #define USBLP_LAST_PROTOCOL     3
 121 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
 122
 123 /*
 124  * some arbitrary status buffer size;
 125  * need a status buffer that is allocated via kmalloc(), not on stack
 126  */
 127 #define STATUS_BUF_SIZE         8
 128
 129 /*
 130  * Locks down the locking order:
 131  * ->wmut locks wstatus.
 132  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
 133  * [rw]status. We only touch status when we know the side idle.
 134  * ->lock locks what interrupt accesses.
 135  */
 136 struct usblp {
 137         struct usb_device       *dev;                   /* USB device */
 138         struct mutex            wmut;
 139         struct mutex            mut;
 140         spinlock_t              lock;           /* locks rcomplete, wcomplete */
 141         char                    *readbuf;               /* read transfer_buffer */
 142         char                    *statusbuf;             /* status transfer_buffer */
 143         struct usb_anchor       urbs;
 144         wait_queue_head_t       rwait, wwait;
 145         int                     readcount;              /* Counter for reads */
 146         int                     ifnum;                  /* Interface number */
 147         struct usb_interface    *intf;                  /* The interface */
 148         /* Alternate-setting numbers and endpoints for each protocol
 149          * (7/1/{index=1,2,3}) that the device supports: */
 150         struct {
 151                 int                             alt_setting;
 152                 struct usb_endpoint_descriptor  *epwrite;
 153                 struct usb_endpoint_descriptor  *epread;
 154         }                       protocol[USBLP_MAX_PROTOCOLS];
 155         int                     current_protocol;
 156         int                     minor;                  /* minor number of device */
 157         int                     wcomplete, rcomplete;
 158         int                     wstatus;        /* bytes written or error */
 159         int                     rstatus;        /* bytes ready or error */
 160         unsigned int            quirks;                 /* quirks flags */
 161         unsigned int            flags;                  /* mode flags */
 162         unsigned char           used;                   /* True if open */
 163         unsigned char           present;                /* True if not disconnected */
 164         unsigned char           bidir;                  /* interface is bidirectional */
 165         unsigned char           sleeping;               /* interface is suspended */
 166         unsigned char           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         int p;
 174
 175         dbg("usblp=0x%p", usblp);
 176         dbg("dev=0x%p", usblp->dev);
 177         dbg("present=%d", usblp->present);
 178         dbg("readbuf=0x%p", usblp->readbuf);
 179         dbg("readcount=%d", usblp->readcount);
 180         dbg("ifnum=%d", usblp->ifnum);
 181     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
 182         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
 183         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
 184         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
 185     }
 186         dbg("current_protocol=%d", usblp->current_protocol);
 187         dbg("minor=%d", usblp->minor);
 188         dbg("wstatus=%d", usblp->wstatus);
 189         dbg("rstatus=%d", usblp->rstatus);
 190         dbg("quirks=%d", usblp->quirks);
 191         dbg("used=%d", usblp->used);
 192         dbg("bidir=%d", usblp->bidir);
 193         dbg("sleeping=%d", usblp->sleeping);
 194         dbg("device_id_string=\"%s\"",
 195                 usblp->device_id_string ?
 196                         usblp->device_id_string + 2 :
 197                         (unsigned char *)"(null)");
 198 }
 199 #endif
 200
 201 /* Quirks: various printer quirks are handled by this table & its flags. */
 202
 203 struct quirk_printer_struct {
 204         __u16 vendorId;
 205         __u16 productId;
 206         unsigned int quirks;
 207 };
 208
 209 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
 210 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
 211 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
 212
 213 static const struct quirk_printer_struct quirk_printers[] = {
 214         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
 215         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
 216         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
 217         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
 218         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
 219         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
 220         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
 221         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
 222         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
 223         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
 224         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
 225         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
 226         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
 227         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
 228         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
 229         { 0, 0 }
 230 };
 231
 232 static int usblp_wwait(struct usblp *usblp, int nonblock);
 233 static int usblp_wtest(struct usblp *usblp, int nonblock);
 234 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
 235 static int usblp_rtest(struct usblp *usblp, int nonblock);
 236 static int usblp_submit_read(struct usblp *usblp);
 237 static int usblp_select_alts(struct usblp *usblp);
 238 static int usblp_set_protocol(struct usblp *usblp, int protocol);
 239 static int usblp_cache_device_id_string(struct usblp *usblp);
 240
 241 /* forward reference to make our lives easier */
 242 static struct usb_driver usblp_driver;
 243 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 244
 245 /*
 246  * Functions for usblp control messages.
 247  */
 248
 249 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
 250 {
 251         int retval;
 252         int index = usblp->ifnum;
 253
 254         /* High byte has the interface index.
 255            Low byte has the alternate setting.
 256          */
 257         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
 258           index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
 259         }
 260
 261         retval = usb_control_msg(usblp->dev,
 262                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
 263                 request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
 264         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
 265                 request, !!dir, recip, value, index, len, retval);
 266         return retval < 0 ? retval : 0;
 267 }
 268
 269 #define usblp_read_status(usblp, status)\
 270         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
 271 #define usblp_get_id(usblp, config, id, maxlen)\
 272         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
 273 #define usblp_reset(usblp)\
 274         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
 275
 276 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
 277         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
 278
 279 /*
 280  * See the description for usblp_select_alts() below for the usage
 281  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
 282  * case of any trouble.
 283  */
 284 static int proto_bias = -1;
 285
 286 /*
 287  * URB callback.
 288  */
 289
 290 static void usblp_bulk_read(struct urb *urb)
 291 {
 292         struct usblp *usblp = urb->context;
 293         int status = urb->status;
 294
 295         if (usblp->present && usblp->used) {
 296                 if (status)
 297                         printk(KERN_WARNING "usblp%d: "
 298                             "nonzero read bulk status received: %d\n",
 299                             usblp->minor, status);
 300         }
 301         spin_lock(&usblp->lock);
 302         if (status < 0)
 303                 usblp->rstatus = status;
 304         else
 305                 usblp->rstatus = urb->actual_length;
 306         usblp->rcomplete = 1;
 307         wake_up(&usblp->rwait);
 308         spin_unlock(&usblp->lock);
 309
 310         usb_free_urb(urb);
 311 }
 312
 313 static void usblp_bulk_write(struct urb *urb)
 314 {
 315         struct usblp *usblp = urb->context;
 316         int status = urb->status;
 317
 318         if (usblp->present && usblp->used) {
 319                 if (status)
 320                         printk(KERN_WARNING "usblp%d: "
 321                             "nonzero write bulk status received: %d\n",
 322                             usblp->minor, status);
 323         }
 324         spin_lock(&usblp->lock);
 325         if (status < 0)
 326                 usblp->wstatus = status;
 327         else
 328                 usblp->wstatus = urb->actual_length;
 329         usblp->no_paper = 0;
 330         usblp->wcomplete = 1;
 331         wake_up(&usblp->wwait);
 332         spin_unlock(&usblp->lock);
 333
 334         usb_free_urb(urb);
 335 }
 336
 337 /*
 338  * Get and print printer errors.
 339  */
 340
 341 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
 342
 343 static int usblp_check_status(struct usblp *usblp, int err)
 344 {
 345         unsigned char status, newerr = 0;
 346         int error;
 347
 348         error = usblp_read_status (usblp, usblp->statusbuf);
 349         if (error < 0) {
 350                 if (printk_ratelimit())
 351                         printk(KERN_ERR
 352                                 "usblp%d: error %d reading printer status\n",
 353                                 usblp->minor, error);
 354                 return 0;
 355         }
 356
 357         status = *usblp->statusbuf;
 358
 359         if (~status & LP_PERRORP)
 360                 newerr = 3;
 361         if (status & LP_POUTPA)
 362                 newerr = 1;
 363         if (~status & LP_PSELECD)
 364                 newerr = 2;
 365
 366         if (newerr != err) {
 367                 printk(KERN_INFO "usblp%d: %s\n",
 368                    usblp->minor, usblp_messages[newerr]);
 369         }
 370
 371         return newerr;
 372 }
 373
 374 static int handle_bidir (struct usblp *usblp)
 375 {
 376         if (usblp->bidir && usblp->used && !usblp->sleeping) {
 377                 if (usblp_submit_read(usblp) < 0)
 378                         return -EIO;
 379         }
 380         return 0;
 381 }
 382
 383 /*
 384  * File op functions.
 385  */
 386
 387 static int usblp_open(struct inode *inode, struct file *file)
 388 {
 389         int minor = iminor(inode);
 390         struct usblp *usblp;
 391         struct usb_interface *intf;
 392         int retval;
 393
 394         if (minor < 0)
 395                 return -ENODEV;
 396
 397         mutex_lock (&usblp_mutex);
 398
 399         retval = -ENODEV;
 400         intf = usb_find_interface(&usblp_driver, minor);
 401         if (!intf) {
 402                 goto out;
 403         }
 404         usblp = usb_get_intfdata (intf);
 405         if (!usblp || !usblp->dev || !usblp->present)
 406                 goto out;
 407
 408         retval = -EBUSY;
 409         if (usblp->used)
 410                 goto out;
 411
 412         /*
 413          * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
 414          *  - We do not want persistent state which close(2) does not clear
 415          *  - It is not used anyway, according to CUPS people
 416          */
 417
 418         retval = usb_autopm_get_interface(intf);
 419         if (retval < 0)
 420                 goto out;
 421         usblp->used = 1;
 422         file->private_data = usblp;
 423
 424         usblp->wcomplete = 1; /* we begin writeable */
 425         usblp->wstatus = 0;
 426         usblp->rcomplete = 0;
 427
 428         if (handle_bidir(usblp) < 0) {
 429                 usblp->used = 0;
 430                 file->private_data = NULL;
 431                 retval = -EIO;
 432         }
 433 out:
 434         mutex_unlock (&usblp_mutex);
 435         return retval;
 436 }
 437
 438 static void usblp_cleanup (struct usblp *usblp)
 439 {
 440         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
 441
 442         kfree(usblp->readbuf);
 443         kfree (usblp->device_id_string);
 444         kfree (usblp->statusbuf);
 445         kfree (usblp);
 446 }
 447
 448 static void usblp_unlink_urbs(struct usblp *usblp)
 449 {
 450         usb_kill_anchored_urbs(&usblp->urbs);
 451 }
 452
 453 static int usblp_release(struct inode *inode, struct file *file)
 454 {
 455         struct usblp *usblp = file->private_data;
 456
 457         usblp->flags &= ~LP_ABORT;
 458
 459         mutex_lock (&usblp_mutex);
 460         usblp->used = 0;
 461         if (usblp->present) {
 462                 usblp_unlink_urbs(usblp);
 463                 usb_autopm_put_interface(usblp->intf);
 464         } else          /* finish cleanup from disconnect */
 465                 usblp_cleanup (usblp);
 466         mutex_unlock (&usblp_mutex);
 467         return 0;
 468 }
 469
 470 /* No kernel lock - fine */
 471 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
 472 {
 473         int ret;
 474         unsigned long flags;
 475
 476         struct usblp *usblp = file->private_data;
 477         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
 478         poll_wait(file, &usblp->rwait, wait);
 479         poll_wait(file, &usblp->wwait, wait);
 480         spin_lock_irqsave(&usblp->lock, flags);
 481         ret = ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
 482            | ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
 483         spin_unlock_irqrestore(&usblp->lock, flags);
 484         return ret;
 485 }
 486
 487 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 488 {
 489         struct usblp *usblp = file->private_data;
 490         int length, err, i;
 491         unsigned char newChannel;
 492         int status;
 493         int twoints[2];
 494         int retval = 0;
 495
 496         mutex_lock (&usblp->mut);
 497         if (!usblp->present) {
 498                 retval = -ENODEV;
 499                 goto done;
 500         }
 501
 502         if (usblp->sleeping) {
 503                 retval = -ENODEV;
 504                 goto done;
 505         }
 506
 507         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
 508                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
 509
 510         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 511
 512                 switch (_IOC_NR(cmd)) {
 513
 514                         case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 515                                 if (_IOC_DIR(cmd) != _IOC_READ) {
 516                                         retval = -EINVAL;
 517                                         goto done;
 518                                 }
 519
 520                                 length = usblp_cache_device_id_string(usblp);
 521                                 if (length < 0) {
 522                                         retval = length;
 523                                         goto done;
 524                                 }
 525                                 if (length > _IOC_SIZE(cmd))
 526                                         length = _IOC_SIZE(cmd); /* truncate */
 527
 528                                 if (copy_to_user((void __user *) arg,
 529                                                 usblp->device_id_string,
 530                                                 (unsigned long) length)) {
 531                                         retval = -EFAULT;
 532                                         goto done;
 533                                 }
 534
 535                                 break;
 536
 537                         case IOCNR_GET_PROTOCOLS:
 538                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 539                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 540                                         retval = -EINVAL;
 541                                         goto done;
 542                                 }
 543
 544                                 twoints[0] = usblp->current_protocol;
 545                                 twoints[1] = 0;
 546                                 for (i = USBLP_FIRST_PROTOCOL;
 547                                      i <= USBLP_LAST_PROTOCOL; i++) {
 548                                         if (usblp->protocol[i].alt_setting >= 0)
 549                                                 twoints[1] |= (1<<i);
 550                                 }
 551
 552                                 if (copy_to_user((void __user *)arg,
 553                                                 (unsigned char *)twoints,
 554                                                 sizeof(twoints))) {
 555                                         retval = -EFAULT;
 556                                         goto done;
 557                                 }
 558
 559                                 break;
 560
 561                         case IOCNR_SET_PROTOCOL:
 562                                 if (_IOC_DIR(cmd) != _IOC_WRITE) {
 563                                         retval = -EINVAL;
 564                                         goto done;
 565                                 }
 566
 567 #ifdef DEBUG
 568                                 if (arg == -10) {
 569                                         usblp_dump(usblp);
 570                                         break;
 571                                 }
 572 #endif
 573
 574                                 usblp_unlink_urbs(usblp);
 575                                 retval = usblp_set_protocol(usblp, arg);
 576                                 if (retval < 0) {
 577                                         usblp_set_protocol(usblp,
 578                                                 usblp->current_protocol);
 579                                 }
 580                                 break;
 581
 582                         case IOCNR_HP_SET_CHANNEL:
 583                                 if (_IOC_DIR(cmd) != _IOC_WRITE ||
 584                                     le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 585                                     usblp->quirks & USBLP_QUIRK_BIDIR) {
 586                                         retval = -EINVAL;
 587                                         goto done;
 588                                 }
 589
 590                                 err = usblp_hp_channel_change_request(usblp,
 591                                         arg, &newChannel);
 592                                 if (err < 0) {
 593                                         err("usblp%d: error = %d setting "
 594                                                 "HP channel",
 595                                                 usblp->minor, err);
 596                                         retval = -EIO;
 597                                         goto done;
 598                                 }
 599
 600                                 dbg("usblp%d requested/got HP channel %ld/%d",
 601                                         usblp->minor, arg, newChannel);
 602                                 break;
 603
 604                         case IOCNR_GET_BUS_ADDRESS:
 605                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 606                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 607                                         retval = -EINVAL;
 608                                         goto done;
 609                                 }
 610
 611                                 twoints[0] = usblp->dev->bus->busnum;
 612                                 twoints[1] = usblp->dev->devnum;
 613                                 if (copy_to_user((void __user *)arg,
 614                                                 (unsigned char *)twoints,
 615                                                 sizeof(twoints))) {
 616                                         retval = -EFAULT;
 617                                         goto done;
 618                                 }
 619
 620                                 dbg("usblp%d is bus=%d, device=%d",
 621                                         usblp->minor, twoints[0], twoints[1]);
 622                                 break;
 623
 624                         case IOCNR_GET_VID_PID:
 625                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 626                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 627                                         retval = -EINVAL;
 628                                         goto done;
 629                                 }
 630
 631                                 twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 632                                 twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 633                                 if (copy_to_user((void __user *)arg,
 634                                                 (unsigned char *)twoints,
 635                                                 sizeof(twoints))) {
 636                                         retval = -EFAULT;
 637                                         goto done;
 638                                 }
 639
 640                                 dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
 641                                         usblp->minor, twoints[0], twoints[1]);
 642                                 break;
 643
 644                         case IOCNR_SOFT_RESET:
 645                                 if (_IOC_DIR(cmd) != _IOC_NONE) {
 646                                         retval = -EINVAL;
 647                                         goto done;
 648                                 }
 649                                 retval = usblp_reset(usblp);
 650                                 break;
 651                         default:
 652                                 retval = -ENOTTY;
 653                 }
 654         else    /* old-style ioctl value */
 655                 switch (cmd) {
 656
 657                         case LPGETSTATUS:
 658                                 if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
 659                                         if (printk_ratelimit())
 660                                                 printk(KERN_ERR "usblp%d:"
 661                                                     "failed reading printer status (%d)\n",
 662                                                     usblp->minor, retval);
 663                                         retval = -EIO;
 664                                         goto done;
 665                                 }
 666                                 status = *usblp->statusbuf;
 667                                 if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
 668                                         retval = -EFAULT;
 669                                 break;
 670
 671                         case LPABORT:
 672                                 if (arg)
 673                                         usblp->flags |= LP_ABORT;
 674                                 else
 675                                         usblp->flags &= ~LP_ABORT;
 676                                 break;
 677
 678                         default:
 679                                 retval = -ENOTTY;
 680                 }
 681
 682 done:
 683         mutex_unlock (&usblp->mut);
 684         return retval;
 685 }
 686
 687 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 688 {
 689         struct usblp *usblp = file->private_data;
 690         char *writebuf;
 691         struct urb *writeurb;
 692         int rv;
 693         int transfer_length;
 694         ssize_t writecount = 0;
 695
 696         if (mutex_lock_interruptible(&usblp->wmut)) {
 697                 rv = -EINTR;
 698                 goto raise_biglock;
 699         }
 700         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 701                 goto raise_wait;
 702
 703         while (writecount < count) {
 704                 /*
 705                  * Step 1: Submit next block.
 706                  */
 707                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 708                         transfer_length = USBLP_BUF_SIZE;
 709
 710                 rv = -ENOMEM;
 711                 if ((writebuf = kmalloc(USBLP_BUF_SIZE, GFP_KERNEL)) == NULL)
 712                         goto raise_buf;
 713                 if ((writeurb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
 714                         goto raise_urb;
 715                 usb_fill_bulk_urb(writeurb, usblp->dev,
 716                         usb_sndbulkpipe(usblp->dev,
 717                           usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 718                         writebuf, transfer_length, usblp_bulk_write, usblp);
 719                 writeurb->transfer_flags |= URB_FREE_BUFFER;
 720                 usb_anchor_urb(writeurb, &usblp->urbs);
 721
 722                 if (copy_from_user(writebuf,
 723                                    buffer + writecount, transfer_length)) {
 724                         rv = -EFAULT;
 725                         goto raise_badaddr;
 726                 }
 727
 728                 spin_lock_irq(&usblp->lock);
 729                 usblp->wcomplete = 0;
 730                 spin_unlock_irq(&usblp->lock);
 731                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 732                         usblp->wstatus = 0;
 733                         spin_lock_irq(&usblp->lock);
 734                         usblp->no_paper = 0;
 735                         usblp->wcomplete = 1;
 736                         wake_up(&usblp->wwait);
 737                         spin_unlock_irq(&usblp->lock);
 738                         if (rv != -ENOMEM)
 739                                 rv = -EIO;
 740                         goto raise_submit;
 741                 }
 742
 743                 /*
 744                  * Step 2: Wait for transfer to end, collect results.
 745                  */
 746                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 747                 if (rv < 0) {
 748                         if (rv == -EAGAIN) {
 749                                 /* Presume that it's going to complete well. */
 750                                 writecount += transfer_length;
 751                         }
 752                         if (rv == -ENOSPC) {
 753                                 spin_lock_irq(&usblp->lock);
 754                                 usblp->no_paper = 1;    /* Mark for poll(2) */
 755                                 spin_unlock_irq(&usblp->lock);
 756                                 writecount += transfer_length;
 757                         }
 758                         /* Leave URB dangling, to be cleaned on close. */
 759                         goto collect_error;
 760                 }
 761
 762                 if (usblp->wstatus < 0) {
 763                         rv = -EIO;
 764                         goto collect_error;
 765                 }
 766                 /*
 767                  * This is critical: it must be our URB, not other writer's.
 768                  * The wmut exists mainly to cover us here.
 769                  */
 770                 writecount += usblp->wstatus;
 771         }
 772
 773         mutex_unlock(&usblp->wmut);
 774         return writecount;
 775
 776 raise_submit:
 777 raise_badaddr:
 778         usb_unanchor_urb(writeurb);
 779         usb_free_urb(writeurb);
 780 raise_urb:
 781         kfree(writebuf);
 782 raise_buf:
 783 raise_wait:
 784 collect_error:          /* Out of raise sequence */
 785         mutex_unlock(&usblp->wmut);
 786 raise_biglock:
 787         return writecount ? writecount : rv;
 788 }
 789
 790 /*
 791  * Notice that we fail to restart in a few cases: on EFAULT, on restart
 792  * error, etc. This is the historical behaviour. In all such cases we return
 793  * EIO, and applications loop in order to get the new read going.
 794  */
 795 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 796 {
 797         struct usblp *usblp = file->private_data;
 798         ssize_t count;
 799         ssize_t avail;
 800         int rv;
 801
 802         if (!usblp->bidir)
 803                 return -EINVAL;
 804
 805         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 806         if (rv < 0)
 807                 return rv;
 808
 809         if ((avail = usblp->rstatus) < 0) {
 810                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 811                     usblp->minor, (int)avail);
 812                 usblp_submit_read(usblp);
 813                 count = -EIO;
 814                 goto done;
 815         }
 816
 817         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 818         if (count != 0 &&
 819             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 820                 count = -EFAULT;
 821                 goto done;
 822         }
 823
 824         if ((usblp->readcount += count) == avail) {
 825                 if (usblp_submit_read(usblp) < 0) {
 826                         /* We don't want to leak USB return codes into errno. */
 827                         if (count == 0)
 828                                 count = -EIO;
 829                         goto done;
 830                 }
 831         }
 832
 833 done:
 834         mutex_unlock (&usblp->mut);
 835         return count;
 836 }
 837
 838 /*
 839  * Wait for the write path to come idle.
 840  * This is called under the ->wmut, so the idle path stays idle.
 841  *
 842  * Our write path has a peculiar property: it does not buffer like a tty,
 843  * but waits for the write to succeed. This allows our ->release to bug out
 844  * without waiting for writes to drain. But it obviously does not work
 845  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 846  * select(2) or poll(2) to wait for the buffer to drain before closing.
 847  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 848  */
 849 static int usblp_wwait(struct usblp *usblp, int nonblock)
 850 {
 851         DECLARE_WAITQUEUE(waita, current);
 852         int rc;
 853         int err = 0;
 854
 855         add_wait_queue(&usblp->wwait, &waita);
 856         for (;;) {
 857                 set_current_state(TASK_INTERRUPTIBLE);
 858                 if (mutex_lock_interruptible(&usblp->mut)) {
 859                         rc = -EINTR;
 860                         break;
 861                 }
 862                 rc = usblp_wtest(usblp, nonblock);
 863                 mutex_unlock(&usblp->mut);
 864                 if (rc <= 0)
 865                         break;
 866
 867                 if (usblp->flags & LP_ABORT) {
 868                         if (schedule_timeout(msecs_to_jiffies(5000)) == 0) {
 869                                 err = usblp_check_status(usblp, err);
 870                                 if (err == 1) { /* Paper out */
 871                                         rc = -ENOSPC;
 872                                         break;
 873                                 }
 874                         }
 875                 } else {
 876                         schedule();
 877                 }
 878         }
 879         set_current_state(TASK_RUNNING);
 880         remove_wait_queue(&usblp->wwait, &waita);
 881         return rc;
 882 }
 883
 884 static int usblp_wtest(struct usblp *usblp, int nonblock)
 885 {
 886         unsigned long flags;
 887
 888         if (!usblp->present)
 889                 return -ENODEV;
 890         if (signal_pending(current))
 891                 return -EINTR;
 892         spin_lock_irqsave(&usblp->lock, flags);
 893         if (usblp->wcomplete) {
 894                 spin_unlock_irqrestore(&usblp->lock, flags);
 895                 return 0;
 896         }
 897         spin_unlock_irqrestore(&usblp->lock, flags);
 898         if (usblp->sleeping)
 899                 return -ENODEV;
 900         if (nonblock)
 901                 return -EAGAIN;
 902         return 1;
 903 }
 904
 905 /*
 906  * Wait for read bytes to become available. This probably should have been
 907  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 908  * name for functions which lock and return.
 909  *
 910  * We do not use wait_event_interruptible because it makes locking iffy.
 911  */
 912 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 913 {
 914         DECLARE_WAITQUEUE(waita, current);
 915         int rc;
 916
 917         add_wait_queue(&usblp->rwait, &waita);
 918         for (;;) {
 919                 if (mutex_lock_interruptible(&usblp->mut)) {
 920                         rc = -EINTR;
 921                         break;
 922                 }
 923                 set_current_state(TASK_INTERRUPTIBLE);
 924                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 925                         mutex_unlock(&usblp->mut);
 926                         break;
 927                 }
 928                 if (rc == 0)    /* Keep it locked */
 929                         break;
 930                 mutex_unlock(&usblp->mut);
 931                 schedule();
 932         }
 933         set_current_state(TASK_RUNNING);
 934         remove_wait_queue(&usblp->rwait, &waita);
 935         return rc;
 936 }
 937
 938 static int usblp_rtest(struct usblp *usblp, int nonblock)
 939 {
 940         unsigned long flags;
 941
 942         if (!usblp->present)
 943                 return -ENODEV;
 944         if (signal_pending(current))
 945                 return -EINTR;
 946         spin_lock_irqsave(&usblp->lock, flags);
 947         if (usblp->rcomplete) {
 948                 spin_unlock_irqrestore(&usblp->lock, flags);
 949                 return 0;
 950         }
 951         spin_unlock_irqrestore(&usblp->lock, flags);
 952         if (usblp->sleeping)
 953                 return -ENODEV;
 954         if (nonblock)
 955                 return -EAGAIN;
 956         return 1;
 957 }
 958
 959 /*
 960  * Please check ->bidir and other such things outside for now.
 961  */
 962 static int usblp_submit_read(struct usblp *usblp)
 963 {
 964         struct urb *urb;
 965         unsigned long flags;
 966         int rc;
 967
 968         rc = -ENOMEM;
 969         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
 970                 goto raise_urb;
 971
 972         usb_fill_bulk_urb(urb, usblp->dev,
 973                 usb_rcvbulkpipe(usblp->dev,
 974                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
 975                 usblp->readbuf, USBLP_BUF_SIZE_IN,
 976                 usblp_bulk_read, usblp);
 977         usb_anchor_urb(urb, &usblp->urbs);
 978
 979         spin_lock_irqsave(&usblp->lock, flags);
 980         usblp->readcount = 0; /* XXX Why here? */
 981         usblp->rcomplete = 0;
 982         spin_unlock_irqrestore(&usblp->lock, flags);
 983         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
 984                 dbg("error submitting urb (%d)", rc);
 985                 spin_lock_irqsave(&usblp->lock, flags);
 986                 usblp->rstatus = rc;
 987                 usblp->rcomplete = 1;
 988                 spin_unlock_irqrestore(&usblp->lock, flags);
 989                 goto raise_submit;
 990         }
 991
 992         return 0;
 993
 994 raise_submit:
 995         usb_unanchor_urb(urb);
 996         usb_free_urb(urb);
 997 raise_urb:
 998         return rc;
 999 }
1000
1001 /*
1002  * Checks for printers that have quirks, such as requiring unidirectional
1003  * communication but reporting bidirectional; currently some HP printers
1004  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1005  * sent at each open (like some Epsons).
1006  * Returns 1 if found, 0 if not found.
1007  *
1008  * HP recommended that we use the bidirectional interface but
1009  * don't attempt any bulk IN transfers from the IN endpoint.
1010  * Here's some more detail on the problem:
1011  * The problem is not that it isn't bidirectional though. The problem
1012  * is that if you request a device ID, or status information, while
1013  * the buffers are full, the return data will end up in the print data
1014  * buffer. For example if you make sure you never request the device ID
1015  * while you are sending print data, and you don't try to query the
1016  * printer status every couple of milliseconds, you will probably be OK.
1017  */
1018 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
1019 {
1020         int i;
1021
1022         for (i = 0; quirk_printers[i].vendorId; i++) {
1023                 if (vendor == quirk_printers[i].vendorId &&
1024                     product == quirk_printers[i].productId)
1025                         return quirk_printers[i].quirks;
1026         }
1027         return 0;
1028 }
1029
1030 static const struct file_operations usblp_fops = {
1031         .owner =        THIS_MODULE,
1032         .read =         usblp_read,
1033         .write =        usblp_write,
1034         .poll =         usblp_poll,
1035         .unlocked_ioctl =       usblp_ioctl,
1036         .compat_ioctl =         usblp_ioctl,
1037         .open =         usblp_open,
1038         .release =      usblp_release,
1039 };
1040
1041 static struct usb_class_driver usblp_class = {
1042         .name =         "lp%d",
1043         .fops =         &usblp_fops,
1044         .minor_base =   USBLP_MINOR_BASE,
1045 };
1046
1047 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1048 {
1049         struct usb_interface *intf = to_usb_interface(dev);
1050         struct usblp *usblp = usb_get_intfdata (intf);
1051
1052         if (usblp->device_id_string[0] == 0 &&
1053             usblp->device_id_string[1] == 0)
1054                 return 0;
1055
1056         return sprintf(buf, "%s", usblp->device_id_string+2);
1057 }
1058
1059 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1060
1061 static int usblp_probe(struct usb_interface *intf,
1062                        const struct usb_device_id *id)
1063 {
1064         struct usb_device *dev = interface_to_usbdev (intf);
1065         struct usblp *usblp = NULL;
1066         int protocol;
1067         int retval;
1068
1069         /* Malloc and start initializing usblp structure so we can use it
1070          * directly. */
1071         if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
1072                 retval = -ENOMEM;
1073                 goto abort;
1074         }
1075         usblp->dev = dev;
1076         mutex_init(&usblp->wmut);
1077         mutex_init (&usblp->mut);
1078         spin_lock_init(&usblp->lock);
1079         init_waitqueue_head(&usblp->rwait);
1080         init_waitqueue_head(&usblp->wwait);
1081         init_usb_anchor(&usblp->urbs);
1082         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1083         usblp->intf = intf;
1084
1085         /* Malloc device ID string buffer to the largest expected length,
1086          * since we can re-query it on an ioctl and a dynamic string
1087          * could change in length. */
1088         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1089                 retval = -ENOMEM;
1090                 goto abort;
1091         }
1092
1093         /*
1094          * Allocate read buffer. We somewhat wastefully
1095          * malloc both regardless of bidirectionality, because the
1096          * alternate setting can be changed later via an ioctl.
1097          */
1098         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1099                 retval = -ENOMEM;
1100                 goto abort;
1101         }
1102
1103         /* Allocate buffer for printer status */
1104         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1105         if (!usblp->statusbuf) {
1106                 retval = -ENOMEM;
1107                 goto abort;
1108         }
1109
1110         /* Lookup quirks for this printer. */
1111         usblp->quirks = usblp_quirks(
1112                 le16_to_cpu(dev->descriptor.idVendor),
1113                 le16_to_cpu(dev->descriptor.idProduct));
1114
1115         /* Analyze and pick initial alternate settings and endpoints. */
1116         protocol = usblp_select_alts(usblp);
1117         if (protocol < 0) {
1118                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1119                         le16_to_cpu(dev->descriptor.idVendor),
1120                         le16_to_cpu(dev->descriptor.idProduct));
1121                 retval = -ENODEV;
1122                 goto abort;
1123         }
1124
1125         /* Setup the selected alternate setting and endpoints. */
1126         if (usblp_set_protocol(usblp, protocol) < 0) {
1127                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1128                 goto abort;
1129         }
1130
1131         /* Retrieve and store the device ID string. */
1132         usblp_cache_device_id_string(usblp);
1133         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1134         if (retval)
1135                 goto abort_intfdata;
1136
1137 #ifdef DEBUG
1138         usblp_check_status(usblp, 0);
1139 #endif
1140
1141         usb_set_intfdata (intf, usblp);
1142
1143         usblp->present = 1;
1144
1145         retval = usb_register_dev(intf, &usblp_class);
1146         if (retval) {
1147                 printk(KERN_ERR "usblp: Not able to get a minor"
1148                     " (base %u, slice default): %d\n",
1149                     USBLP_MINOR_BASE, retval);
1150                 goto abort_intfdata;
1151         }
1152         usblp->minor = intf->minor;
1153         printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1154                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1155                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1156                 usblp->ifnum,
1157                 usblp->protocol[usblp->current_protocol].alt_setting,
1158                 usblp->current_protocol,
1159                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1160                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1161
1162         return 0;
1163
1164 abort_intfdata:
1165         usb_set_intfdata (intf, NULL);
1166         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1167 abort:
1168         if (usblp) {
1169                 kfree(usblp->readbuf);
1170                 kfree(usblp->statusbuf);
1171                 kfree(usblp->device_id_string);
1172                 kfree(usblp);
1173         }
1174         return retval;
1175 }
1176
1177 /*
1178  * We are a "new" style driver with usb_device_id table,
1179  * but our requirements are too intricate for simple match to handle.
1180  *
1181  * The "proto_bias" option may be used to specify the preferred protocol
1182  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1183  * supports the preferred protocol, then we bind to it.
1184  *
1185  * The best interface for us is 7/1/2, because it is compatible
1186  * with a stream of characters. If we find it, we bind to it.
1187  *
1188  * Note that the people from hpoj.sourceforge.net need to be able to
1189  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1190  *
1191  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1192  * stream-compatible, because this matches the behaviour of the old code.
1193  *
1194  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1195  */
1196 static int usblp_select_alts(struct usblp *usblp)
1197 {
1198         struct usb_interface *if_alt;
1199         struct usb_host_interface *ifd;
1200         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1201         int p, i, e;
1202
1203         if_alt = usblp->intf;
1204
1205         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1206                 usblp->protocol[p].alt_setting = -1;
1207
1208         /* Find out what we have. */
1209         for (i = 0; i < if_alt->num_altsetting; i++) {
1210                 ifd = &if_alt->altsetting[i];
1211
1212                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1213                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1214                                 continue;
1215
1216                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1217                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1218                         continue;
1219
1220                 /* Look for bulk OUT and IN endpoints. */
1221                 epwrite = epread = NULL;
1222                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1223                         epd = &ifd->endpoint[e].desc;
1224
1225                         if (usb_endpoint_is_bulk_out(epd))
1226                                 if (!epwrite)
1227                                         epwrite = epd;
1228
1229                         if (usb_endpoint_is_bulk_in(epd))
1230                                 if (!epread)
1231                                         epread = epd;
1232                 }
1233
1234                 /* Ignore buggy hardware without the right endpoints. */
1235                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1236                         continue;
1237
1238                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1239                  * and buggy bidirectional printers. */
1240                 if (ifd->desc.bInterfaceProtocol == 1) {
1241                         epread = NULL;
1242                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1243                         printk(KERN_INFO "usblp%d: Disabling reads from "
1244                             "problematic bidirectional printer\n",
1245                             usblp->minor);
1246                         epread = NULL;
1247                 }
1248
1249                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1250                                 ifd->desc.bAlternateSetting;
1251                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1252                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1253         }
1254
1255         /* If our requested protocol is supported, then use it. */
1256         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1257             proto_bias <= USBLP_LAST_PROTOCOL &&
1258             usblp->protocol[proto_bias].alt_setting != -1)
1259                 return proto_bias;
1260
1261         /* Ordering is important here. */
1262         if (usblp->protocol[2].alt_setting != -1)
1263                 return 2;
1264         if (usblp->protocol[1].alt_setting != -1)
1265                 return 1;
1266         if (usblp->protocol[3].alt_setting != -1)
1267                 return 3;
1268
1269         /* If nothing is available, then don't bind to this device. */
1270         return -1;
1271 }
1272
1273 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1274 {
1275         int r, alts;
1276
1277         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1278                 return -EINVAL;
1279
1280         alts = usblp->protocol[protocol].alt_setting;
1281         if (alts < 0)
1282                 return -EINVAL;
1283         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1284         if (r < 0) {
1285                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1286                         alts, usblp->ifnum);
1287                 return r;
1288         }
1289
1290         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1291         usblp->current_protocol = protocol;
1292         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1293         return 0;
1294 }
1295
1296 /* Retrieves and caches device ID string.
1297  * Returns length, including length bytes but not null terminator.
1298  * On error, returns a negative errno value. */
1299 static int usblp_cache_device_id_string(struct usblp *usblp)
1300 {
1301         int err, length;
1302
1303         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1304         if (err < 0) {
1305                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1306                         usblp->minor, err);
1307                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1308                 return -EIO;
1309         }
1310
1311         /* First two bytes are length in big-endian.
1312          * They count themselves, and we copy them into
1313          * the user's buffer. */
1314         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1315         if (length < 2)
1316                 length = 2;
1317         else if (length >= USBLP_DEVICE_ID_SIZE)
1318                 length = USBLP_DEVICE_ID_SIZE - 1;
1319         usblp->device_id_string[length] = '\0';
1320
1321         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1322                 usblp->minor, length, &usblp->device_id_string[2]);
1323
1324         return length;
1325 }
1326
1327 static void usblp_disconnect(struct usb_interface *intf)
1328 {
1329         struct usblp *usblp = usb_get_intfdata (intf);
1330
1331         usb_deregister_dev(intf, &usblp_class);
1332
1333         if (!usblp || !usblp->dev) {
1334                 err("bogus disconnect");
1335                 BUG ();
1336         }
1337
1338         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1339
1340         mutex_lock (&usblp_mutex);
1341         mutex_lock (&usblp->mut);
1342         usblp->present = 0;
1343         wake_up(&usblp->wwait);
1344         wake_up(&usblp->rwait);
1345         usb_set_intfdata (intf, NULL);
1346
1347         usblp_unlink_urbs(usblp);
1348         mutex_unlock (&usblp->mut);
1349
1350         if (!usblp->used)
1351                 usblp_cleanup (usblp);
1352         mutex_unlock (&usblp_mutex);
1353 }
1354
1355 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1356 {
1357         struct usblp *usblp = usb_get_intfdata (intf);
1358
1359         /* we take no more IO */
1360         usblp->sleeping = 1;
1361         usblp_unlink_urbs(usblp);
1362 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1363         /* not strictly necessary, but just in case */
1364         wake_up(&usblp->wwait);
1365         wake_up(&usblp->rwait);
1366 #endif
1367
1368         return 0;
1369 }
1370
1371 static int usblp_resume (struct usb_interface *intf)
1372 {
1373         struct usblp *usblp = usb_get_intfdata (intf);
1374         int r;
1375
1376         usblp->sleeping = 0;
1377         r = handle_bidir (usblp);
1378
1379         return r;
1380 }
1381
1382 static struct usb_device_id usblp_ids [] = {
1383         { USB_DEVICE_INFO(7, 1, 1) },
1384         { USB_DEVICE_INFO(7, 1, 2) },
1385         { USB_DEVICE_INFO(7, 1, 3) },
1386         { USB_INTERFACE_INFO(7, 1, 1) },
1387         { USB_INTERFACE_INFO(7, 1, 2) },
1388         { USB_INTERFACE_INFO(7, 1, 3) },
1389         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1390         { }                                             /* Terminating entry */
1391 };
1392
1393 MODULE_DEVICE_TABLE (usb, usblp_ids);
1394
1395 static struct usb_driver usblp_driver = {
1396         .name =         "usblp",
1397         .probe =        usblp_probe,
1398         .disconnect =   usblp_disconnect,
1399         .suspend =      usblp_suspend,
1400         .resume =       usblp_resume,
1401         .id_table =     usblp_ids,
1402         .supports_autosuspend = 1,
1403 };
1404
1405 static int __init usblp_init(void)
1406 {
1407         return usb_register(&usblp_driver);
1408 }
1409
1410 static void __exit usblp_exit(void)
1411 {
1412         usb_deregister(&usblp_driver);
1413 }
1414
1415 module_init(usblp_init);
1416 module_exit(usblp_exit);
1417
1418 MODULE_AUTHOR( DRIVER_AUTHOR );
1419 MODULE_DESCRIPTION( DRIVER_DESC );
1420 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1421 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1422 MODULE_LICENSE("GPL");