drivers/usb/class/usblp.c

   1 /*
   2  * usblp.c
   3  *
   4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
   5  * Copyright (c) 1999 Pavel Machek      <pavel@ucw.cz>
   6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
   7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
   8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
   9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
  10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
  11  *
  12  * USB Printer Device Class driver for USB printers and printer cables
  13  *
  14  * Sponsored by SuSE
  15  *
  16  * ChangeLog:
  17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
  18  *      v0.2 - some more cleanups
  19  *      v0.3 - cleaner again, waitqueue fixes
  20  *      v0.4 - fixes in unidirectional mode
  21  *      v0.5 - add DEVICE_ID string support
  22  *      v0.6 - never time out
  23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
  24  *      v0.8 - add devfs support
  25  *      v0.9 - fix unplug-while-open paths
  26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
  27  *      v0.11 - add proto_bias option (Pete Zaitcev)
  28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
  29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
  30  *              use usb_alloc_coherent() for read buf & write buf;
  31  *      none  - Maintained in Linux kernel after v0.13
  32  */
  33
  34 /*
  35  * This program is free software; you can redistribute it and/or modify
  36  * it under the terms of the GNU General Public License as published by
  37  * the Free Software Foundation; either version 2 of the License, or
  38  * (at your option) any later version.
  39  *
  40  * This program is distributed in the hope that it will be useful,
  41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  43  * GNU General Public License for more details.
  44  *
  45  * You should have received a copy of the GNU General Public License
  46  * along with this program; if not, write to the Free Software
  47  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/kernel.h>
  52 #include <linux/sched.h>
  53 #include <linux/signal.h>
  54 #include <linux/poll.h>
  55 #include <linux/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 #include <linux/ratelimit.h>
  62
  63 /*
  64  * Version Information
  65  */
  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_BUF_SIZE_IN       1024
  71 #define USBLP_DEVICE_ID_SIZE    1024
  72
  73 /* ioctls: */
  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_CTL_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 /*
 132  * Locks down the locking order:
 133  * ->wmut locks wstatus.
 134  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
 135  * [rw]status. We only touch status when we know the side idle.
 136  * ->lock locks what interrupt accesses.
 137  */
 138 struct usblp {
 139         struct usb_device       *dev;                   /* USB device */
 140         struct mutex            wmut;
 141         struct mutex            mut;
 142         spinlock_t              lock;           /* locks rcomplete, wcomplete */
 143         char                    *readbuf;               /* read transfer_buffer */
 144         char                    *statusbuf;             /* status transfer_buffer */
 145         struct usb_anchor       urbs;
 146         wait_queue_head_t       rwait, wwait;
 147         int                     readcount;              /* Counter for reads */
 148         int                     ifnum;                  /* Interface number */
 149         struct usb_interface    *intf;                  /* The interface */
 150         /* Alternate-setting numbers and endpoints for each protocol
 151          * (7/1/{index=1,2,3}) that the device supports: */
 152         struct {
 153                 int                             alt_setting;
 154                 struct usb_endpoint_descriptor  *epwrite;
 155                 struct usb_endpoint_descriptor  *epread;
 156         }                       protocol[USBLP_MAX_PROTOCOLS];
 157         int                     current_protocol;
 158         int                     minor;                  /* minor number of device */
 159         int                     wcomplete, rcomplete;
 160         int                     wstatus;        /* bytes written or error */
 161         int                     rstatus;        /* bytes ready or error */
 162         unsigned int            quirks;                 /* quirks flags */
 163         unsigned int            flags;                  /* mode flags */
 164         unsigned char           used;                   /* True if open */
 165         unsigned char           present;                /* True if not disconnected */
 166         unsigned char           bidir;                  /* interface is bidirectional */
 167         unsigned char           no_paper;               /* Paper Out happened */
 168         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
 169                                                         /* first 2 bytes are (big-endian) length */
 170 };
 171
 172 #ifdef DEBUG
 173 static void usblp_dump(struct usblp *usblp)
 174 {
 175         int p;
 176
 177         dbg("usblp=0x%p", usblp);
 178         dbg("dev=0x%p", usblp->dev);
 179         dbg("present=%d", usblp->present);
 180         dbg("readbuf=0x%p", usblp->readbuf);
 181         dbg("readcount=%d", usblp->readcount);
 182         dbg("ifnum=%d", usblp->ifnum);
 183     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
 184         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
 185         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
 186         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
 187     }
 188         dbg("current_protocol=%d", usblp->current_protocol);
 189         dbg("minor=%d", usblp->minor);
 190         dbg("wstatus=%d", usblp->wstatus);
 191         dbg("rstatus=%d", usblp->rstatus);
 192         dbg("quirks=%d", usblp->quirks);
 193         dbg("used=%d", usblp->used);
 194         dbg("bidir=%d", usblp->bidir);
 195         dbg("device_id_string=\"%s\"",
 196                 usblp->device_id_string ?
 197                         usblp->device_id_string + 2 :
 198                         (unsigned char *)"(null)");
 199 }
 200 #endif
 201
 202 /* Quirks: various printer quirks are handled by this table & its flags. */
 203
 204 struct quirk_printer_struct {
 205         __u16 vendorId;
 206         __u16 productId;
 207         unsigned int quirks;
 208 };
 209
 210 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
 211 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
 212 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
 213
 214 static const struct quirk_printer_struct quirk_printers[] = {
 215         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
 216         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
 217         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
 218         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
 219         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
 220         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
 221         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
 222         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
 223         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
 224         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
 225         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
 226         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
 227         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
 228         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
 229         { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
 230         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
 231         { 0, 0 }
 232 };
 233
 234 static int usblp_wwait(struct usblp *usblp, int nonblock);
 235 static int usblp_wtest(struct usblp *usblp, int nonblock);
 236 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
 237 static int usblp_rtest(struct usblp *usblp, int nonblock);
 238 static int usblp_submit_read(struct usblp *usblp);
 239 static int usblp_select_alts(struct usblp *usblp);
 240 static int usblp_set_protocol(struct usblp *usblp, int protocol);
 241 static int usblp_cache_device_id_string(struct usblp *usblp);
 242
 243 /* forward reference to make our lives easier */
 244 static struct usb_driver usblp_driver;
 245 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 246
 247 /*
 248  * Functions for usblp control messages.
 249  */
 250
 251 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
 252 {
 253         int retval;
 254         int index = usblp->ifnum;
 255
 256         /* High byte has the interface index.
 257            Low byte has the alternate setting.
 258          */
 259         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
 260                 index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
 261
 262         retval = usb_control_msg(usblp->dev,
 263                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
 264                 request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
 265         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
 266                 request, !!dir, recip, value, index, len, retval);
 267         return retval < 0 ? retval : 0;
 268 }
 269
 270 #define usblp_read_status(usblp, status)\
 271         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
 272 #define usblp_get_id(usblp, config, id, maxlen)\
 273         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
 274 #define usblp_reset(usblp)\
 275         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
 276
 277 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
 278         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
 279
 280 /*
 281  * See the description for usblp_select_alts() below for the usage
 282  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
 283  * case of any trouble.
 284  */
 285 static int proto_bias = -1;
 286
 287 /*
 288  * URB callback.
 289  */
 290
 291 static void usblp_bulk_read(struct urb *urb)
 292 {
 293         struct usblp *usblp = urb->context;
 294         int status = urb->status;
 295
 296         if (usblp->present && usblp->used) {
 297                 if (status)
 298                         printk(KERN_WARNING "usblp%d: "
 299                             "nonzero read bulk status received: %d\n",
 300                             usblp->minor, status);
 301         }
 302         spin_lock(&usblp->lock);
 303         if (status < 0)
 304                 usblp->rstatus = status;
 305         else
 306                 usblp->rstatus = urb->actual_length;
 307         usblp->rcomplete = 1;
 308         wake_up(&usblp->rwait);
 309         spin_unlock(&usblp->lock);
 310
 311         usb_free_urb(urb);
 312 }
 313
 314 static void usblp_bulk_write(struct urb *urb)
 315 {
 316         struct usblp *usblp = urb->context;
 317         int status = urb->status;
 318
 319         if (usblp->present && usblp->used) {
 320                 if (status)
 321                         printk(KERN_WARNING "usblp%d: "
 322                             "nonzero write bulk status received: %d\n",
 323                             usblp->minor, status);
 324         }
 325         spin_lock(&usblp->lock);
 326         if (status < 0)
 327                 usblp->wstatus = status;
 328         else
 329                 usblp->wstatus = urb->actual_length;
 330         usblp->no_paper = 0;
 331         usblp->wcomplete = 1;
 332         wake_up(&usblp->wwait);
 333         spin_unlock(&usblp->lock);
 334
 335         usb_free_urb(urb);
 336 }
 337
 338 /*
 339  * Get and print printer errors.
 340  */
 341
 342 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
 343
 344 static int usblp_check_status(struct usblp *usblp, int err)
 345 {
 346         unsigned char status, newerr = 0;
 347         int error;
 348
 349         mutex_lock(&usblp->mut);
 350         if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
 351                 mutex_unlock(&usblp->mut);
 352                 printk_ratelimited(KERN_ERR
 353                                 "usblp%d: error %d reading printer status\n",
 354                                 usblp->minor, error);
 355                 return 0;
 356         }
 357         status = *usblp->statusbuf;
 358         mutex_unlock(&usblp->mut);
 359
 360         if (~status & LP_PERRORP)
 361                 newerr = 3;
 362         if (status & LP_POUTPA)
 363                 newerr = 1;
 364         if (~status & LP_PSELECD)
 365                 newerr = 2;
 366
 367         if (newerr != err) {
 368                 printk(KERN_INFO "usblp%d: %s\n",
 369                    usblp->minor, usblp_messages[newerr]);
 370         }
 371
 372         return newerr;
 373 }
 374
 375 static int handle_bidir(struct usblp *usblp)
 376 {
 377         if (usblp->bidir && usblp->used) {
 378                 if (usblp_submit_read(usblp) < 0)
 379                         return -EIO;
 380         }
 381         return 0;
 382 }
 383
 384 /*
 385  * File op functions.
 386  */
 387
 388 static int usblp_open(struct inode *inode, struct file *file)
 389 {
 390         int minor = iminor(inode);
 391         struct usblp *usblp;
 392         struct usb_interface *intf;
 393         int retval;
 394
 395         if (minor < 0)
 396                 return -ENODEV;
 397
 398         mutex_lock(&usblp_mutex);
 399
 400         retval = -ENODEV;
 401         intf = usb_find_interface(&usblp_driver, minor);
 402         if (!intf)
 403                 goto out;
 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                 usb_autopm_put_interface(intf);
 430                 usblp->used = 0;
 431                 file->private_data = NULL;
 432                 retval = -EIO;
 433         }
 434 out:
 435         mutex_unlock(&usblp_mutex);
 436         return retval;
 437 }
 438
 439 static void usblp_cleanup(struct usblp *usblp)
 440 {
 441         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
 442
 443         kfree(usblp->readbuf);
 444         kfree(usblp->device_id_string);
 445         kfree(usblp->statusbuf);
 446         kfree(usblp);
 447 }
 448
 449 static void usblp_unlink_urbs(struct usblp *usblp)
 450 {
 451         usb_kill_anchored_urbs(&usblp->urbs);
 452 }
 453
 454 static int usblp_release(struct inode *inode, struct file *file)
 455 {
 456         struct usblp *usblp = file->private_data;
 457
 458         usblp->flags &= ~LP_ABORT;
 459
 460         mutex_lock(&usblp_mutex);
 461         usblp->used = 0;
 462         if (usblp->present) {
 463                 usblp_unlink_urbs(usblp);
 464                 usb_autopm_put_interface(usblp->intf);
 465         } else          /* finish cleanup from disconnect */
 466                 usblp_cleanup(usblp);
 467         mutex_unlock(&usblp_mutex);
 468         return 0;
 469 }
 470
 471 /* No kernel lock - fine */
 472 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
 473 {
 474         int ret;
 475         unsigned long flags;
 476
 477         struct usblp *usblp = file->private_data;
 478         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
 479         poll_wait(file, &usblp->rwait, wait);
 480         poll_wait(file, &usblp->wwait, wait);
 481         spin_lock_irqsave(&usblp->lock, flags);
 482         ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
 483            ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
 484         spin_unlock_irqrestore(&usblp->lock, flags);
 485         return ret;
 486 }
 487
 488 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 489 {
 490         struct usblp *usblp = file->private_data;
 491         int length, err, i;
 492         unsigned char newChannel;
 493         int status;
 494         int twoints[2];
 495         int retval = 0;
 496
 497         mutex_lock(&usblp->mut);
 498         if (!usblp->present) {
 499                 retval = -ENODEV;
 500                 goto done;
 501         }
 502
 503         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
 504                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
 505
 506         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 507
 508                 switch (_IOC_NR(cmd)) {
 509
 510                 case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 511                         if (_IOC_DIR(cmd) != _IOC_READ) {
 512                                 retval = -EINVAL;
 513                                 goto done;
 514                         }
 515
 516                         length = usblp_cache_device_id_string(usblp);
 517                         if (length < 0) {
 518                                 retval = length;
 519                                 goto done;
 520                         }
 521                         if (length > _IOC_SIZE(cmd))
 522                                 length = _IOC_SIZE(cmd); /* truncate */
 523
 524                         if (copy_to_user((void __user *) arg,
 525                                         usblp->device_id_string,
 526                                         (unsigned long) length)) {
 527                                 retval = -EFAULT;
 528                                 goto done;
 529                         }
 530
 531                         break;
 532
 533                 case IOCNR_GET_PROTOCOLS:
 534                         if (_IOC_DIR(cmd) != _IOC_READ ||
 535                             _IOC_SIZE(cmd) < sizeof(twoints)) {
 536                                 retval = -EINVAL;
 537                                 goto done;
 538                         }
 539
 540                         twoints[0] = usblp->current_protocol;
 541                         twoints[1] = 0;
 542                         for (i = USBLP_FIRST_PROTOCOL;
 543                              i <= USBLP_LAST_PROTOCOL; i++) {
 544                                 if (usblp->protocol[i].alt_setting >= 0)
 545                                         twoints[1] |= (1<<i);
 546                         }
 547
 548                         if (copy_to_user((void __user *)arg,
 549                                         (unsigned char *)twoints,
 550                                         sizeof(twoints))) {
 551                                 retval = -EFAULT;
 552                                 goto done;
 553                         }
 554
 555                         break;
 556
 557                 case IOCNR_SET_PROTOCOL:
 558                         if (_IOC_DIR(cmd) != _IOC_WRITE) {
 559                                 retval = -EINVAL;
 560                                 goto done;
 561                         }
 562
 563 #ifdef DEBUG
 564                         if (arg == -10) {
 565                                 usblp_dump(usblp);
 566                                 break;
 567                         }
 568 #endif
 569
 570                         usblp_unlink_urbs(usblp);
 571                         retval = usblp_set_protocol(usblp, arg);
 572                         if (retval < 0) {
 573                                 usblp_set_protocol(usblp,
 574                                         usblp->current_protocol);
 575                         }
 576                         break;
 577
 578                 case IOCNR_HP_SET_CHANNEL:
 579                         if (_IOC_DIR(cmd) != _IOC_WRITE ||
 580                             le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 581                             usblp->quirks & USBLP_QUIRK_BIDIR) {
 582                                 retval = -EINVAL;
 583                                 goto done;
 584                         }
 585
 586                         err = usblp_hp_channel_change_request(usblp,
 587                                 arg, &newChannel);
 588                         if (err < 0) {
 589                                 dev_err(&usblp->dev->dev,
 590                                         "usblp%d: error = %d setting "
 591                                         "HP channel\n",
 592                                         usblp->minor, err);
 593                                 retval = -EIO;
 594                                 goto done;
 595                         }
 596
 597                         dbg("usblp%d requested/got HP channel %ld/%d",
 598                                 usblp->minor, arg, newChannel);
 599                         break;
 600
 601                 case IOCNR_GET_BUS_ADDRESS:
 602                         if (_IOC_DIR(cmd) != _IOC_READ ||
 603                             _IOC_SIZE(cmd) < sizeof(twoints)) {
 604                                 retval = -EINVAL;
 605                                 goto done;
 606                         }
 607
 608                         twoints[0] = usblp->dev->bus->busnum;
 609                         twoints[1] = usblp->dev->devnum;
 610                         if (copy_to_user((void __user *)arg,
 611                                         (unsigned char *)twoints,
 612                                         sizeof(twoints))) {
 613                                 retval = -EFAULT;
 614                                 goto done;
 615                         }
 616
 617                         dbg("usblp%d is bus=%d, device=%d",
 618                                 usblp->minor, twoints[0], twoints[1]);
 619                         break;
 620
 621                 case IOCNR_GET_VID_PID:
 622                         if (_IOC_DIR(cmd) != _IOC_READ ||
 623                             _IOC_SIZE(cmd) < sizeof(twoints)) {
 624                                 retval = -EINVAL;
 625                                 goto done;
 626                         }
 627
 628                         twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 629                         twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 630                         if (copy_to_user((void __user *)arg,
 631                                         (unsigned char *)twoints,
 632                                         sizeof(twoints))) {
 633                                 retval = -EFAULT;
 634                                 goto done;
 635                         }
 636
 637                         dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
 638                                 usblp->minor, twoints[0], twoints[1]);
 639                         break;
 640
 641                 case IOCNR_SOFT_RESET:
 642                         if (_IOC_DIR(cmd) != _IOC_NONE) {
 643                                 retval = -EINVAL;
 644                                 goto done;
 645                         }
 646                         retval = usblp_reset(usblp);
 647                         break;
 648                 default:
 649                         retval = -ENOTTY;
 650                 }
 651         else    /* old-style ioctl value */
 652                 switch (cmd) {
 653
 654                 case LPGETSTATUS:
 655                         if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
 656                                 printk_ratelimited(KERN_ERR "usblp%d:"
 657                                             "failed reading printer status (%d)\n",
 658                                             usblp->minor, retval);
 659                                 retval = -EIO;
 660                                 goto done;
 661                         }
 662                         status = *usblp->statusbuf;
 663                         if (copy_to_user((void __user *)arg, &status, sizeof(int)))
 664                                 retval = -EFAULT;
 665                         break;
 666
 667                 case LPABORT:
 668                         if (arg)
 669                                 usblp->flags |= LP_ABORT;
 670                         else
 671                                 usblp->flags &= ~LP_ABORT;
 672                         break;
 673
 674                 default:
 675                         retval = -ENOTTY;
 676                 }
 677
 678 done:
 679         mutex_unlock(&usblp->mut);
 680         return retval;
 681 }
 682
 683 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
 684 {
 685         struct urb *urb;
 686         char *writebuf;
 687
 688         if ((writebuf = kmalloc(transfer_length, GFP_KERNEL)) == NULL)
 689                 return NULL;
 690         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL) {
 691                 kfree(writebuf);
 692                 return NULL;
 693         }
 694
 695         usb_fill_bulk_urb(urb, usblp->dev,
 696                 usb_sndbulkpipe(usblp->dev,
 697                  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 698                 writebuf, transfer_length, usblp_bulk_write, usblp);
 699         urb->transfer_flags |= URB_FREE_BUFFER;
 700
 701         return urb;
 702 }
 703
 704 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 705 {
 706         struct usblp *usblp = file->private_data;
 707         struct urb *writeurb;
 708         int rv;
 709         int transfer_length;
 710         ssize_t writecount = 0;
 711
 712         if (mutex_lock_interruptible(&usblp->wmut)) {
 713                 rv = -EINTR;
 714                 goto raise_biglock;
 715         }
 716         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 717                 goto raise_wait;
 718
 719         while (writecount < count) {
 720                 /*
 721                  * Step 1: Submit next block.
 722                  */
 723                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 724                         transfer_length = USBLP_BUF_SIZE;
 725
 726                 rv = -ENOMEM;
 727                 if ((writeurb = usblp_new_writeurb(usblp, transfer_length)) == NULL)
 728                         goto raise_urb;
 729                 usb_anchor_urb(writeurb, &usblp->urbs);
 730
 731                 if (copy_from_user(writeurb->transfer_buffer,
 732                                    buffer + writecount, transfer_length)) {
 733                         rv = -EFAULT;
 734                         goto raise_badaddr;
 735                 }
 736
 737                 spin_lock_irq(&usblp->lock);
 738                 usblp->wcomplete = 0;
 739                 spin_unlock_irq(&usblp->lock);
 740                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 741                         usblp->wstatus = 0;
 742                         spin_lock_irq(&usblp->lock);
 743                         usblp->no_paper = 0;
 744                         usblp->wcomplete = 1;
 745                         wake_up(&usblp->wwait);
 746                         spin_unlock_irq(&usblp->lock);
 747                         if (rv != -ENOMEM)
 748                                 rv = -EIO;
 749                         goto raise_submit;
 750                 }
 751
 752                 /*
 753                  * Step 2: Wait for transfer to end, collect results.
 754                  */
 755                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 756                 if (rv < 0) {
 757                         if (rv == -EAGAIN) {
 758                                 /* Presume that it's going to complete well. */
 759                                 writecount += transfer_length;
 760                         }
 761                         if (rv == -ENOSPC) {
 762                                 spin_lock_irq(&usblp->lock);
 763                                 usblp->no_paper = 1;    /* Mark for poll(2) */
 764                                 spin_unlock_irq(&usblp->lock);
 765                                 writecount += transfer_length;
 766                         }
 767                         /* Leave URB dangling, to be cleaned on close. */
 768                         goto collect_error;
 769                 }
 770
 771                 if (usblp->wstatus < 0) {
 772                         rv = -EIO;
 773                         goto collect_error;
 774                 }
 775                 /*
 776                  * This is critical: it must be our URB, not other writer's.
 777                  * The wmut exists mainly to cover us here.
 778                  */
 779                 writecount += usblp->wstatus;
 780         }
 781
 782         mutex_unlock(&usblp->wmut);
 783         return writecount;
 784
 785 raise_submit:
 786 raise_badaddr:
 787         usb_unanchor_urb(writeurb);
 788         usb_free_urb(writeurb);
 789 raise_urb:
 790 raise_wait:
 791 collect_error:          /* Out of raise sequence */
 792         mutex_unlock(&usblp->wmut);
 793 raise_biglock:
 794         return writecount ? writecount : rv;
 795 }
 796
 797 /*
 798  * Notice that we fail to restart in a few cases: on EFAULT, on restart
 799  * error, etc. This is the historical behaviour. In all such cases we return
 800  * EIO, and applications loop in order to get the new read going.
 801  */
 802 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 803 {
 804         struct usblp *usblp = file->private_data;
 805         ssize_t count;
 806         ssize_t avail;
 807         int rv;
 808
 809         if (!usblp->bidir)
 810                 return -EINVAL;
 811
 812         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 813         if (rv < 0)
 814                 return rv;
 815
 816         if ((avail = usblp->rstatus) < 0) {
 817                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 818                     usblp->minor, (int)avail);
 819                 usblp_submit_read(usblp);
 820                 count = -EIO;
 821                 goto done;
 822         }
 823
 824         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 825         if (count != 0 &&
 826             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 827                 count = -EFAULT;
 828                 goto done;
 829         }
 830
 831         if ((usblp->readcount += count) == avail) {
 832                 if (usblp_submit_read(usblp) < 0) {
 833                         /* We don't want to leak USB return codes into errno. */
 834                         if (count == 0)
 835                                 count = -EIO;
 836                         goto done;
 837                 }
 838         }
 839
 840 done:
 841         mutex_unlock(&usblp->mut);
 842         return count;
 843 }
 844
 845 /*
 846  * Wait for the write path to come idle.
 847  * This is called under the ->wmut, so the idle path stays idle.
 848  *
 849  * Our write path has a peculiar property: it does not buffer like a tty,
 850  * but waits for the write to succeed. This allows our ->release to bug out
 851  * without waiting for writes to drain. But it obviously does not work
 852  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 853  * select(2) or poll(2) to wait for the buffer to drain before closing.
 854  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 855  */
 856 static int usblp_wwait(struct usblp *usblp, int nonblock)
 857 {
 858         DECLARE_WAITQUEUE(waita, current);
 859         int rc;
 860         int err = 0;
 861
 862         add_wait_queue(&usblp->wwait, &waita);
 863         for (;;) {
 864                 if (mutex_lock_interruptible(&usblp->mut)) {
 865                         rc = -EINTR;
 866                         break;
 867                 }
 868                 set_current_state(TASK_INTERRUPTIBLE);
 869                 rc = usblp_wtest(usblp, nonblock);
 870                 mutex_unlock(&usblp->mut);
 871                 if (rc <= 0)
 872                         break;
 873
 874                 if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
 875                         if (usblp->flags & LP_ABORT) {
 876                                 err = usblp_check_status(usblp, err);
 877                                 if (err == 1) { /* Paper out */
 878                                         rc = -ENOSPC;
 879                                         break;
 880                                 }
 881                         } else {
 882                                 /* Prod the printer, Gentoo#251237. */
 883                                 mutex_lock(&usblp->mut);
 884                                 usblp_read_status(usblp, usblp->statusbuf);
 885                                 mutex_unlock(&usblp->mut);
 886                         }
 887                 }
 888         }
 889         set_current_state(TASK_RUNNING);
 890         remove_wait_queue(&usblp->wwait, &waita);
 891         return rc;
 892 }
 893
 894 static int usblp_wtest(struct usblp *usblp, int nonblock)
 895 {
 896         unsigned long flags;
 897
 898         if (!usblp->present)
 899                 return -ENODEV;
 900         if (signal_pending(current))
 901                 return -EINTR;
 902         spin_lock_irqsave(&usblp->lock, flags);
 903         if (usblp->wcomplete) {
 904                 spin_unlock_irqrestore(&usblp->lock, flags);
 905                 return 0;
 906         }
 907         spin_unlock_irqrestore(&usblp->lock, flags);
 908         if (nonblock)
 909                 return -EAGAIN;
 910         return 1;
 911 }
 912
 913 /*
 914  * Wait for read bytes to become available. This probably should have been
 915  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 916  * name for functions which lock and return.
 917  *
 918  * We do not use wait_event_interruptible because it makes locking iffy.
 919  */
 920 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 921 {
 922         DECLARE_WAITQUEUE(waita, current);
 923         int rc;
 924
 925         add_wait_queue(&usblp->rwait, &waita);
 926         for (;;) {
 927                 if (mutex_lock_interruptible(&usblp->mut)) {
 928                         rc = -EINTR;
 929                         break;
 930                 }
 931                 set_current_state(TASK_INTERRUPTIBLE);
 932                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 933                         mutex_unlock(&usblp->mut);
 934                         break;
 935                 }
 936                 if (rc == 0)    /* Keep it locked */
 937                         break;
 938                 mutex_unlock(&usblp->mut);
 939                 schedule();
 940         }
 941         set_current_state(TASK_RUNNING);
 942         remove_wait_queue(&usblp->rwait, &waita);
 943         return rc;
 944 }
 945
 946 static int usblp_rtest(struct usblp *usblp, int nonblock)
 947 {
 948         unsigned long flags;
 949
 950         if (!usblp->present)
 951                 return -ENODEV;
 952         if (signal_pending(current))
 953                 return -EINTR;
 954         spin_lock_irqsave(&usblp->lock, flags);
 955         if (usblp->rcomplete) {
 956                 spin_unlock_irqrestore(&usblp->lock, flags);
 957                 return 0;
 958         }
 959         spin_unlock_irqrestore(&usblp->lock, flags);
 960         if (nonblock)
 961                 return -EAGAIN;
 962         return 1;
 963 }
 964
 965 /*
 966  * Please check ->bidir and other such things outside for now.
 967  */
 968 static int usblp_submit_read(struct usblp *usblp)
 969 {
 970         struct urb *urb;
 971         unsigned long flags;
 972         int rc;
 973
 974         rc = -ENOMEM;
 975         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
 976                 goto raise_urb;
 977
 978         usb_fill_bulk_urb(urb, usblp->dev,
 979                 usb_rcvbulkpipe(usblp->dev,
 980                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
 981                 usblp->readbuf, USBLP_BUF_SIZE_IN,
 982                 usblp_bulk_read, usblp);
 983         usb_anchor_urb(urb, &usblp->urbs);
 984
 985         spin_lock_irqsave(&usblp->lock, flags);
 986         usblp->readcount = 0; /* XXX Why here? */
 987         usblp->rcomplete = 0;
 988         spin_unlock_irqrestore(&usblp->lock, flags);
 989         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
 990                 dbg("error submitting urb (%d)", rc);
 991                 spin_lock_irqsave(&usblp->lock, flags);
 992                 usblp->rstatus = rc;
 993                 usblp->rcomplete = 1;
 994                 spin_unlock_irqrestore(&usblp->lock, flags);
 995                 goto raise_submit;
 996         }
 997
 998         return 0;
 999
1000 raise_submit:
1001         usb_unanchor_urb(urb);
1002         usb_free_urb(urb);
1003 raise_urb:
1004         return rc;
1005 }
1006
1007 /*
1008  * Checks for printers that have quirks, such as requiring unidirectional
1009  * communication but reporting bidirectional; currently some HP printers
1010  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1011  * sent at each open (like some Epsons).
1012  * Returns 1 if found, 0 if not found.
1013  *
1014  * HP recommended that we use the bidirectional interface but
1015  * don't attempt any bulk IN transfers from the IN endpoint.
1016  * Here's some more detail on the problem:
1017  * The problem is not that it isn't bidirectional though. The problem
1018  * is that if you request a device ID, or status information, while
1019  * the buffers are full, the return data will end up in the print data
1020  * buffer. For example if you make sure you never request the device ID
1021  * while you are sending print data, and you don't try to query the
1022  * printer status every couple of milliseconds, you will probably be OK.
1023  */
1024 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1025 {
1026         int i;
1027
1028         for (i = 0; quirk_printers[i].vendorId; i++) {
1029                 if (vendor == quirk_printers[i].vendorId &&
1030                     product == quirk_printers[i].productId)
1031                         return quirk_printers[i].quirks;
1032         }
1033         return 0;
1034 }
1035
1036 static const struct file_operations usblp_fops = {
1037         .owner =        THIS_MODULE,
1038         .read =         usblp_read,
1039         .write =        usblp_write,
1040         .poll =         usblp_poll,
1041         .unlocked_ioctl =       usblp_ioctl,
1042         .compat_ioctl =         usblp_ioctl,
1043         .open =         usblp_open,
1044         .release =      usblp_release,
1045         .llseek =       noop_llseek,
1046 };
1047
1048 static char *usblp_devnode(struct device *dev, mode_t *mode)
1049 {
1050         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1051 }
1052
1053 static struct usb_class_driver usblp_class = {
1054         .name =         "lp%d",
1055         .devnode =      usblp_devnode,
1056         .fops =         &usblp_fops,
1057         .minor_base =   USBLP_MINOR_BASE,
1058 };
1059
1060 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1061 {
1062         struct usb_interface *intf = to_usb_interface(dev);
1063         struct usblp *usblp = usb_get_intfdata(intf);
1064
1065         if (usblp->device_id_string[0] == 0 &&
1066             usblp->device_id_string[1] == 0)
1067                 return 0;
1068
1069         return sprintf(buf, "%s", usblp->device_id_string+2);
1070 }
1071
1072 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1073
1074 static int usblp_probe(struct usb_interface *intf,
1075                        const struct usb_device_id *id)
1076 {
1077         struct usb_device *dev = interface_to_usbdev(intf);
1078         struct usblp *usblp;
1079         int protocol;
1080         int retval;
1081
1082         /* Malloc and start initializing usblp structure so we can use it
1083          * directly. */
1084         usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1085         if (!usblp) {
1086                 retval = -ENOMEM;
1087                 goto abort_ret;
1088         }
1089         usblp->dev = dev;
1090         mutex_init(&usblp->wmut);
1091         mutex_init(&usblp->mut);
1092         spin_lock_init(&usblp->lock);
1093         init_waitqueue_head(&usblp->rwait);
1094         init_waitqueue_head(&usblp->wwait);
1095         init_usb_anchor(&usblp->urbs);
1096         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1097         usblp->intf = intf;
1098
1099         /* Malloc device ID string buffer to the largest expected length,
1100          * since we can re-query it on an ioctl and a dynamic string
1101          * could change in length. */
1102         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1103                 retval = -ENOMEM;
1104                 goto abort;
1105         }
1106
1107         /*
1108          * Allocate read buffer. We somewhat wastefully
1109          * malloc both regardless of bidirectionality, because the
1110          * alternate setting can be changed later via an ioctl.
1111          */
1112         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1113                 retval = -ENOMEM;
1114                 goto abort;
1115         }
1116
1117         /* Allocate buffer for printer status */
1118         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1119         if (!usblp->statusbuf) {
1120                 retval = -ENOMEM;
1121                 goto abort;
1122         }
1123
1124         /* Lookup quirks for this printer. */
1125         usblp->quirks = usblp_quirks(
1126                 le16_to_cpu(dev->descriptor.idVendor),
1127                 le16_to_cpu(dev->descriptor.idProduct));
1128
1129         /* Analyze and pick initial alternate settings and endpoints. */
1130         protocol = usblp_select_alts(usblp);
1131         if (protocol < 0) {
1132                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1133                         le16_to_cpu(dev->descriptor.idVendor),
1134                         le16_to_cpu(dev->descriptor.idProduct));
1135                 retval = -ENODEV;
1136                 goto abort;
1137         }
1138
1139         /* Setup the selected alternate setting and endpoints. */
1140         if (usblp_set_protocol(usblp, protocol) < 0) {
1141                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1142                 goto abort;
1143         }
1144
1145         /* Retrieve and store the device ID string. */
1146         usblp_cache_device_id_string(usblp);
1147         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1148         if (retval)
1149                 goto abort_intfdata;
1150
1151 #ifdef DEBUG
1152         usblp_check_status(usblp, 0);
1153 #endif
1154
1155         usb_set_intfdata(intf, usblp);
1156
1157         usblp->present = 1;
1158
1159         retval = usb_register_dev(intf, &usblp_class);
1160         if (retval) {
1161                 printk(KERN_ERR "usblp: Not able to get a minor"
1162                     " (base %u, slice default): %d\n",
1163                     USBLP_MINOR_BASE, retval);
1164                 goto abort_intfdata;
1165         }
1166         usblp->minor = intf->minor;
1167         printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1168                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1169                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1170                 usblp->ifnum,
1171                 usblp->protocol[usblp->current_protocol].alt_setting,
1172                 usblp->current_protocol,
1173                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1174                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1175
1176         return 0;
1177
1178 abort_intfdata:
1179         usb_set_intfdata(intf, NULL);
1180         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1181 abort:
1182         kfree(usblp->readbuf);
1183         kfree(usblp->statusbuf);
1184         kfree(usblp->device_id_string);
1185         kfree(usblp);
1186 abort_ret:
1187         return retval;
1188 }
1189
1190 /*
1191  * We are a "new" style driver with usb_device_id table,
1192  * but our requirements are too intricate for simple match to handle.
1193  *
1194  * The "proto_bias" option may be used to specify the preferred protocol
1195  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1196  * supports the preferred protocol, then we bind to it.
1197  *
1198  * The best interface for us is 7/1/2, because it is compatible
1199  * with a stream of characters. If we find it, we bind to it.
1200  *
1201  * Note that the people from hpoj.sourceforge.net need to be able to
1202  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1203  *
1204  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1205  * stream-compatible, because this matches the behaviour of the old code.
1206  *
1207  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1208  */
1209 static int usblp_select_alts(struct usblp *usblp)
1210 {
1211         struct usb_interface *if_alt;
1212         struct usb_host_interface *ifd;
1213         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1214         int p, i, e;
1215
1216         if_alt = usblp->intf;
1217
1218         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1219                 usblp->protocol[p].alt_setting = -1;
1220
1221         /* Find out what we have. */
1222         for (i = 0; i < if_alt->num_altsetting; i++) {
1223                 ifd = &if_alt->altsetting[i];
1224
1225                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1226                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1227                                 continue;
1228
1229                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1230                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1231                         continue;
1232
1233                 /* Look for bulk OUT and IN endpoints. */
1234                 epwrite = epread = NULL;
1235                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1236                         epd = &ifd->endpoint[e].desc;
1237
1238                         if (usb_endpoint_is_bulk_out(epd))
1239                                 if (!epwrite)
1240                                         epwrite = epd;
1241
1242                         if (usb_endpoint_is_bulk_in(epd))
1243                                 if (!epread)
1244                                         epread = epd;
1245                 }
1246
1247                 /* Ignore buggy hardware without the right endpoints. */
1248                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1249                         continue;
1250
1251                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1252                  * and buggy bidirectional printers. */
1253                 if (ifd->desc.bInterfaceProtocol == 1) {
1254                         epread = NULL;
1255                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1256                         printk(KERN_INFO "usblp%d: Disabling reads from "
1257                             "problematic bidirectional printer\n",
1258                             usblp->minor);
1259                         epread = NULL;
1260                 }
1261
1262                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1263                                 ifd->desc.bAlternateSetting;
1264                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1265                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1266         }
1267
1268         /* If our requested protocol is supported, then use it. */
1269         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1270             proto_bias <= USBLP_LAST_PROTOCOL &&
1271             usblp->protocol[proto_bias].alt_setting != -1)
1272                 return proto_bias;
1273
1274         /* Ordering is important here. */
1275         if (usblp->protocol[2].alt_setting != -1)
1276                 return 2;
1277         if (usblp->protocol[1].alt_setting != -1)
1278                 return 1;
1279         if (usblp->protocol[3].alt_setting != -1)
1280                 return 3;
1281
1282         /* If nothing is available, then don't bind to this device. */
1283         return -1;
1284 }
1285
1286 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1287 {
1288         int r, alts;
1289
1290         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1291                 return -EINVAL;
1292
1293         alts = usblp->protocol[protocol].alt_setting;
1294         if (alts < 0)
1295                 return -EINVAL;
1296         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1297         if (r < 0) {
1298                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1299                         alts, usblp->ifnum);
1300                 return r;
1301         }
1302
1303         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1304         usblp->current_protocol = protocol;
1305         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1306         return 0;
1307 }
1308
1309 /* Retrieves and caches device ID string.
1310  * Returns length, including length bytes but not null terminator.
1311  * On error, returns a negative errno value. */
1312 static int usblp_cache_device_id_string(struct usblp *usblp)
1313 {
1314         int err, length;
1315
1316         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1317         if (err < 0) {
1318                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1319                         usblp->minor, err);
1320                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1321                 return -EIO;
1322         }
1323
1324         /* First two bytes are length in big-endian.
1325          * They count themselves, and we copy them into
1326          * the user's buffer. */
1327         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1328         if (length < 2)
1329                 length = 2;
1330         else if (length >= USBLP_DEVICE_ID_SIZE)
1331                 length = USBLP_DEVICE_ID_SIZE - 1;
1332         usblp->device_id_string[length] = '\0';
1333
1334         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1335                 usblp->minor, length, &usblp->device_id_string[2]);
1336
1337         return length;
1338 }
1339
1340 static void usblp_disconnect(struct usb_interface *intf)
1341 {
1342         struct usblp *usblp = usb_get_intfdata(intf);
1343
1344         usb_deregister_dev(intf, &usblp_class);
1345
1346         if (!usblp || !usblp->dev) {
1347                 dev_err(&intf->dev, "bogus disconnect\n");
1348                 BUG();
1349         }
1350
1351         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1352
1353         mutex_lock(&usblp_mutex);
1354         mutex_lock(&usblp->mut);
1355         usblp->present = 0;
1356         wake_up(&usblp->wwait);
1357         wake_up(&usblp->rwait);
1358         usb_set_intfdata(intf, NULL);
1359
1360         usblp_unlink_urbs(usblp);
1361         mutex_unlock(&usblp->mut);
1362
1363         if (!usblp->used)
1364                 usblp_cleanup(usblp);
1365         mutex_unlock(&usblp_mutex);
1366 }
1367
1368 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1369 {
1370         struct usblp *usblp = usb_get_intfdata(intf);
1371
1372         usblp_unlink_urbs(usblp);
1373 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1374         /* not strictly necessary, but just in case */
1375         wake_up(&usblp->wwait);
1376         wake_up(&usblp->rwait);
1377 #endif
1378
1379         return 0;
1380 }
1381
1382 static int usblp_resume(struct usb_interface *intf)
1383 {
1384         struct usblp *usblp = usb_get_intfdata(intf);
1385         int r;
1386
1387         r = handle_bidir(usblp);
1388
1389         return r;
1390 }
1391
1392 static const struct usb_device_id usblp_ids[] = {
1393         { USB_DEVICE_INFO(7, 1, 1) },
1394         { USB_DEVICE_INFO(7, 1, 2) },
1395         { USB_DEVICE_INFO(7, 1, 3) },
1396         { USB_INTERFACE_INFO(7, 1, 1) },
1397         { USB_INTERFACE_INFO(7, 1, 2) },
1398         { USB_INTERFACE_INFO(7, 1, 3) },
1399         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1400         { }                                             /* Terminating entry */
1401 };
1402
1403 MODULE_DEVICE_TABLE(usb, usblp_ids);
1404
1405 static struct usb_driver usblp_driver = {
1406         .name =         "usblp",
1407         .probe =        usblp_probe,
1408         .disconnect =   usblp_disconnect,
1409         .suspend =      usblp_suspend,
1410         .resume =       usblp_resume,
1411         .id_table =     usblp_ids,
1412         .supports_autosuspend = 1,
1413 };
1414
1415 static int __init usblp_init(void)
1416 {
1417         return usb_register(&usblp_driver);
1418 }
1419
1420 static void __exit usblp_exit(void)
1421 {
1422         usb_deregister(&usblp_driver);
1423 }
1424
1425 module_init(usblp_init);
1426 module_exit(usblp_exit);
1427
1428 MODULE_AUTHOR(DRIVER_AUTHOR);
1429 MODULE_DESCRIPTION(DRIVER_DESC);
1430 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1431 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1432 MODULE_LICENSE("GPL");