drivers/usb/class/usblp.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * usblp.c
   4  *
   5  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
   6  * Copyright (c) 1999 Pavel Machek      <pavel@ucw.cz>
   7  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
   8  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
   9  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
  10  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
  11  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
  12  *
  13  * USB Printer Device Class driver for USB printers and printer cables
  14  *
  15  * Sponsored by SuSE
  16  *
  17  * ChangeLog:
  18  *      v0.1 - thorough cleaning, URBification, almost a rewrite
  19  *      v0.2 - some more cleanups
  20  *      v0.3 - cleaner again, waitqueue fixes
  21  *      v0.4 - fixes in unidirectional mode
  22  *      v0.5 - add DEVICE_ID string support
  23  *      v0.6 - never time out
  24  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
  25  *      v0.8 - add devfs support
  26  *      v0.9 - fix unplug-while-open paths
  27  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
  28  *      v0.11 - add proto_bias option (Pete Zaitcev)
  29  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
  30  *      v0.13 - alloc space for statusbuf (<status> not on stack);
  31  *              use usb_alloc_coherent() for read buf & write buf;
  32  *      none  - Maintained in Linux kernel after v0.13
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/kernel.h>
  37 #include <linux/sched/signal.h>
  38 #include <linux/signal.h>
  39 #include <linux/poll.h>
  40 #include <linux/slab.h>
  41 #include <linux/lp.h>
  42 #include <linux/mutex.h>
  43 #undef DEBUG
  44 #include <linux/usb.h>
  45 #include <linux/usb/ch9.h>
  46 #include <linux/ratelimit.h>
  47
  48 /*
  49  * Version Information
  50  */
  51 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
  52 #define DRIVER_DESC "USB Printer Device Class driver"
  53
  54 #define USBLP_BUF_SIZE          8192
  55 #define USBLP_BUF_SIZE_IN       1024
  56 #define USBLP_DEVICE_ID_SIZE    1024
  57
  58 /* ioctls: */
  59 #define IOCNR_GET_DEVICE_ID             1
  60 #define IOCNR_GET_PROTOCOLS             2
  61 #define IOCNR_SET_PROTOCOL              3
  62 #define IOCNR_HP_SET_CHANNEL            4
  63 #define IOCNR_GET_BUS_ADDRESS           5
  64 #define IOCNR_GET_VID_PID               6
  65 #define IOCNR_SOFT_RESET                7
  66 /* Get device_id string: */
  67 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
  68 /* The following ioctls were added for http://hpoj.sourceforge.net:
  69  * Get two-int array:
  70  * [0]=current protocol
  71  *     (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
  72  *         3=USB_CLASS_PRINTER/1/3),
  73  * [1]=supported protocol mask (mask&(1<<n)!=0 means
  74  *     USB_CLASS_PRINTER/1/n supported):
  75  */
  76 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
  77 /*
  78  * Set protocol
  79  *     (arg: 1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
  80  *         3=USB_CLASS_PRINTER/1/3):
  81  */
  82 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
  83 /* Set channel number (HP Vendor-specific command): */
  84 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
  85 /* Get two-int array: [0]=bus number, [1]=device address: */
  86 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
  87 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
  88 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
  89 /* Perform class specific soft reset */
  90 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
  91
  92 /*
  93  * A DEVICE_ID string may include the printer's serial number.
  94  * It should end with a semi-colon (';').
  95  * An example from an HP 970C DeskJet printer is (this is one long string,
  96  * with the serial number changed):
  97 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:                    ;
  98  */
  99
 100 /*
 101  * USB Printer Requests
 102  */
 103
 104 #define USBLP_REQ_GET_ID                        0x00
 105 #define USBLP_REQ_GET_STATUS                    0x01
 106 #define USBLP_REQ_RESET                         0x02
 107 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
 108
 109 #define USBLP_MINORS            16
 110 #define USBLP_MINOR_BASE        0
 111
 112 #define USBLP_CTL_TIMEOUT       5000                    /* 5 seconds */
 113
 114 #define USBLP_FIRST_PROTOCOL    1
 115 #define USBLP_LAST_PROTOCOL     3
 116 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
 117
 118 /*
 119  * some arbitrary status buffer size;
 120  * need a status buffer that is allocated via kmalloc(), not on stack
 121  */
 122 #define STATUS_BUF_SIZE         8
 123
 124 /*
 125  * Locks down the locking order:
 126  * ->wmut locks wstatus.
 127  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
 128  * [rw]status. We only touch status when we know the side idle.
 129  * ->lock locks what interrupt accesses.
 130  */
 131 struct usblp {
 132         struct usb_device       *dev;                   /* USB device */
 133         struct mutex            wmut;
 134         struct mutex            mut;
 135         spinlock_t              lock;           /* locks rcomplete, wcomplete */
 136         char                    *readbuf;               /* read transfer_buffer */
 137         char                    *statusbuf;             /* status transfer_buffer */
 138         struct usb_anchor       urbs;
 139         wait_queue_head_t       rwait, wwait;
 140         int                     readcount;              /* Counter for reads */
 141         int                     ifnum;                  /* Interface number */
 142         struct usb_interface    *intf;                  /* The interface */
 143         /*
 144          * Alternate-setting numbers and endpoints for each protocol
 145          * (USB_CLASS_PRINTER/1/{index=1,2,3}) that the device supports:
 146          */
 147         struct {
 148                 int                             alt_setting;
 149                 struct usb_endpoint_descriptor  *epwrite;
 150                 struct usb_endpoint_descriptor  *epread;
 151         }                       protocol[USBLP_MAX_PROTOCOLS];
 152         int                     current_protocol;
 153         int                     minor;                  /* minor number of device */
 154         int                     wcomplete, rcomplete;
 155         int                     wstatus;        /* bytes written or error */
 156         int                     rstatus;        /* bytes ready or error */
 157         unsigned int            quirks;                 /* quirks flags */
 158         unsigned int            flags;                  /* mode flags */
 159         unsigned char           used;                   /* True if open */
 160         unsigned char           present;                /* True if not disconnected */
 161         unsigned char           bidir;                  /* interface is bidirectional */
 162         unsigned char           no_paper;               /* Paper Out happened */
 163         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
 164                                                         /* first 2 bytes are (big-endian) length */
 165 };
 166
 167 #ifdef DEBUG
 168 static void usblp_dump(struct usblp *usblp)
 169 {
 170         struct device *dev = &usblp->intf->dev;
 171         int p;
 172
 173         dev_dbg(dev, "usblp=0x%p\n", usblp);
 174         dev_dbg(dev, "dev=0x%p\n", usblp->dev);
 175         dev_dbg(dev, "present=%d\n", usblp->present);
 176         dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
 177         dev_dbg(dev, "readcount=%d\n", usblp->readcount);
 178         dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
 179         for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
 180                 dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
 181                         usblp->protocol[p].alt_setting);
 182                 dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
 183                         usblp->protocol[p].epwrite);
 184                 dev_dbg(dev, "protocol[%d].epread=%p\n", p,
 185                         usblp->protocol[p].epread);
 186         }
 187         dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
 188         dev_dbg(dev, "minor=%d\n", usblp->minor);
 189         dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
 190         dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
 191         dev_dbg(dev, "quirks=%d\n", usblp->quirks);
 192         dev_dbg(dev, "used=%d\n", usblp->used);
 193         dev_dbg(dev, "bidir=%d\n", usblp->bidir);
 194         dev_dbg(dev, "device_id_string=\"%s\"\n",
 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         { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
 229         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
 230         { 0, 0 }
 231 };
 232
 233 static int usblp_wwait(struct usblp *usblp, int nonblock);
 234 static int usblp_wtest(struct usblp *usblp, int nonblock);
 235 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
 236 static int usblp_rtest(struct usblp *usblp, int nonblock);
 237 static int usblp_submit_read(struct usblp *usblp);
 238 static int usblp_select_alts(struct usblp *usblp);
 239 static int usblp_set_protocol(struct usblp *usblp, int protocol);
 240 static int usblp_cache_device_id_string(struct usblp *usblp);
 241
 242 /* forward reference to make our lives easier */
 243 static struct usb_driver usblp_driver;
 244 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 245
 246 /*
 247  * Functions for usblp control messages.
 248  */
 249
 250 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
 251 {
 252         int retval;
 253         int index = usblp->ifnum;
 254
 255         /* High byte has the interface index.
 256            Low byte has the alternate setting.
 257          */
 258         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
 259                 index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
 260
 261         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_CTL_TIMEOUT);
 264         dev_dbg(&usblp->intf->dev,
 265                 "usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
 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 /sys/kernel/debug/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 __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
 473 {
 474         __poll_t 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         dev_dbg(&usblp->intf->dev,
 504                 "usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
 505                 _IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
 506
 507         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 508
 509                 switch (_IOC_NR(cmd)) {
 510
 511                 case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 512                         if (_IOC_DIR(cmd) != _IOC_READ) {
 513                                 retval = -EINVAL;
 514                                 goto done;
 515                         }
 516
 517                         length = usblp_cache_device_id_string(usblp);
 518                         if (length < 0) {
 519                                 retval = length;
 520                                 goto done;
 521                         }
 522                         if (length > _IOC_SIZE(cmd))
 523                                 length = _IOC_SIZE(cmd); /* truncate */
 524
 525                         if (copy_to_user((void __user *) arg,
 526                                         usblp->device_id_string,
 527                                         (unsigned long) length)) {
 528                                 retval = -EFAULT;
 529                                 goto done;
 530                         }
 531
 532                         break;
 533
 534                 case IOCNR_GET_PROTOCOLS:
 535                         if (_IOC_DIR(cmd) != _IOC_READ ||
 536                             _IOC_SIZE(cmd) < sizeof(twoints)) {
 537                                 retval = -EINVAL;
 538                                 goto done;
 539                         }
 540
 541                         twoints[0] = usblp->current_protocol;
 542                         twoints[1] = 0;
 543                         for (i = USBLP_FIRST_PROTOCOL;
 544                              i <= USBLP_LAST_PROTOCOL; i++) {
 545                                 if (usblp->protocol[i].alt_setting >= 0)
 546                                         twoints[1] |= (1<<i);
 547                         }
 548
 549                         if (copy_to_user((void __user *)arg,
 550                                         (unsigned char *)twoints,
 551                                         sizeof(twoints))) {
 552                                 retval = -EFAULT;
 553                                 goto done;
 554                         }
 555
 556                         break;
 557
 558                 case IOCNR_SET_PROTOCOL:
 559                         if (_IOC_DIR(cmd) != _IOC_WRITE) {
 560                                 retval = -EINVAL;
 561                                 goto done;
 562                         }
 563
 564 #ifdef DEBUG
 565                         if (arg == -10) {
 566                                 usblp_dump(usblp);
 567                                 break;
 568                         }
 569 #endif
 570
 571                         usblp_unlink_urbs(usblp);
 572                         retval = usblp_set_protocol(usblp, arg);
 573                         if (retval < 0) {
 574                                 usblp_set_protocol(usblp,
 575                                         usblp->current_protocol);
 576                         }
 577                         break;
 578
 579                 case IOCNR_HP_SET_CHANNEL:
 580                         if (_IOC_DIR(cmd) != _IOC_WRITE ||
 581                             le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 582                             usblp->quirks & USBLP_QUIRK_BIDIR) {
 583                                 retval = -EINVAL;
 584                                 goto done;
 585                         }
 586
 587                         err = usblp_hp_channel_change_request(usblp,
 588                                 arg, &newChannel);
 589                         if (err < 0) {
 590                                 dev_err(&usblp->dev->dev,
 591                                         "usblp%d: error = %d setting "
 592                                         "HP channel\n",
 593                                         usblp->minor, err);
 594                                 retval = -EIO;
 595                                 goto done;
 596                         }
 597
 598                         dev_dbg(&usblp->intf->dev,
 599                                 "usblp%d requested/got HP channel %ld/%d\n",
 600                                 usblp->minor, arg, newChannel);
 601                         break;
 602
 603                 case IOCNR_GET_BUS_ADDRESS:
 604                         if (_IOC_DIR(cmd) != _IOC_READ ||
 605                             _IOC_SIZE(cmd) < sizeof(twoints)) {
 606                                 retval = -EINVAL;
 607                                 goto done;
 608                         }
 609
 610                         twoints[0] = usblp->dev->bus->busnum;
 611                         twoints[1] = usblp->dev->devnum;
 612                         if (copy_to_user((void __user *)arg,
 613                                         (unsigned char *)twoints,
 614                                         sizeof(twoints))) {
 615                                 retval = -EFAULT;
 616                                 goto done;
 617                         }
 618
 619                         dev_dbg(&usblp->intf->dev,
 620                                 "usblp%d is bus=%d, device=%d\n",
 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                         dev_dbg(&usblp->intf->dev,
 641                                 "usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
 642                                 usblp->minor, twoints[0], twoints[1]);
 643                         break;
 644
 645                 case IOCNR_SOFT_RESET:
 646                         if (_IOC_DIR(cmd) != _IOC_NONE) {
 647                                 retval = -EINVAL;
 648                                 goto done;
 649                         }
 650                         retval = usblp_reset(usblp);
 651                         break;
 652                 default:
 653                         retval = -ENOTTY;
 654                 }
 655         else    /* old-style ioctl value */
 656                 switch (cmd) {
 657
 658                 case LPGETSTATUS:
 659                         retval = usblp_read_status(usblp, usblp->statusbuf);
 660                         if (retval) {
 661                                 printk_ratelimited(KERN_ERR "usblp%d:"
 662                                             "failed reading printer status (%d)\n",
 663                                             usblp->minor, retval);
 664                                 retval = -EIO;
 665                                 goto done;
 666                         }
 667                         status = *usblp->statusbuf;
 668                         if (copy_to_user((void __user *)arg, &status, sizeof(int)))
 669                                 retval = -EFAULT;
 670                         break;
 671
 672                 case LPABORT:
 673                         if (arg)
 674                                 usblp->flags |= LP_ABORT;
 675                         else
 676                                 usblp->flags &= ~LP_ABORT;
 677                         break;
 678
 679                 default:
 680                         retval = -ENOTTY;
 681                 }
 682
 683 done:
 684         mutex_unlock(&usblp->mut);
 685         return retval;
 686 }
 687
 688 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
 689 {
 690         struct urb *urb;
 691         char *writebuf;
 692
 693         writebuf = kmalloc(transfer_length, GFP_KERNEL);
 694         if (writebuf == NULL)
 695                 return NULL;
 696         urb = usb_alloc_urb(0, GFP_KERNEL);
 697         if (urb == NULL) {
 698                 kfree(writebuf);
 699                 return NULL;
 700         }
 701
 702         usb_fill_bulk_urb(urb, usblp->dev,
 703                 usb_sndbulkpipe(usblp->dev,
 704                  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 705                 writebuf, transfer_length, usblp_bulk_write, usblp);
 706         urb->transfer_flags |= URB_FREE_BUFFER;
 707
 708         return urb;
 709 }
 710
 711 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 712 {
 713         struct usblp *usblp = file->private_data;
 714         struct urb *writeurb;
 715         int rv;
 716         int transfer_length;
 717         ssize_t writecount = 0;
 718
 719         if (mutex_lock_interruptible(&usblp->wmut)) {
 720                 rv = -EINTR;
 721                 goto raise_biglock;
 722         }
 723         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 724                 goto raise_wait;
 725
 726         while (writecount < count) {
 727                 /*
 728                  * Step 1: Submit next block.
 729                  */
 730                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 731                         transfer_length = USBLP_BUF_SIZE;
 732
 733                 rv = -ENOMEM;
 734                 writeurb = usblp_new_writeurb(usblp, transfer_length);
 735                 if (writeurb == NULL)
 736                         goto raise_urb;
 737                 usb_anchor_urb(writeurb, &usblp->urbs);
 738
 739                 if (copy_from_user(writeurb->transfer_buffer,
 740                                    buffer + writecount, transfer_length)) {
 741                         rv = -EFAULT;
 742                         goto raise_badaddr;
 743                 }
 744
 745                 spin_lock_irq(&usblp->lock);
 746                 usblp->wcomplete = 0;
 747                 spin_unlock_irq(&usblp->lock);
 748                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 749                         usblp->wstatus = 0;
 750                         spin_lock_irq(&usblp->lock);
 751                         usblp->no_paper = 0;
 752                         usblp->wcomplete = 1;
 753                         wake_up(&usblp->wwait);
 754                         spin_unlock_irq(&usblp->lock);
 755                         if (rv != -ENOMEM)
 756                                 rv = -EIO;
 757                         goto raise_submit;
 758                 }
 759
 760                 /*
 761                  * Step 2: Wait for transfer to end, collect results.
 762                  */
 763                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 764                 if (rv < 0) {
 765                         if (rv == -EAGAIN) {
 766                                 /* Presume that it's going to complete well. */
 767                                 writecount += transfer_length;
 768                         }
 769                         if (rv == -ENOSPC) {
 770                                 spin_lock_irq(&usblp->lock);
 771                                 usblp->no_paper = 1;    /* Mark for poll(2) */
 772                                 spin_unlock_irq(&usblp->lock);
 773                                 writecount += transfer_length;
 774                         }
 775                         /* Leave URB dangling, to be cleaned on close. */
 776                         goto collect_error;
 777                 }
 778
 779                 if (usblp->wstatus < 0) {
 780                         rv = -EIO;
 781                         goto collect_error;
 782                 }
 783                 /*
 784                  * This is critical: it must be our URB, not other writer's.
 785                  * The wmut exists mainly to cover us here.
 786                  */
 787                 writecount += usblp->wstatus;
 788         }
 789
 790         mutex_unlock(&usblp->wmut);
 791         return writecount;
 792
 793 raise_submit:
 794 raise_badaddr:
 795         usb_unanchor_urb(writeurb);
 796         usb_free_urb(writeurb);
 797 raise_urb:
 798 raise_wait:
 799 collect_error:          /* Out of raise sequence */
 800         mutex_unlock(&usblp->wmut);
 801 raise_biglock:
 802         return writecount ? writecount : rv;
 803 }
 804
 805 /*
 806  * Notice that we fail to restart in a few cases: on EFAULT, on restart
 807  * error, etc. This is the historical behaviour. In all such cases we return
 808  * EIO, and applications loop in order to get the new read going.
 809  */
 810 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 811 {
 812         struct usblp *usblp = file->private_data;
 813         ssize_t count;
 814         ssize_t avail;
 815         int rv;
 816
 817         if (!usblp->bidir)
 818                 return -EINVAL;
 819
 820         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 821         if (rv < 0)
 822                 return rv;
 823
 824         if ((avail = usblp->rstatus) < 0) {
 825                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 826                     usblp->minor, (int)avail);
 827                 usblp_submit_read(usblp);
 828                 count = -EIO;
 829                 goto done;
 830         }
 831
 832         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 833         if (count != 0 &&
 834             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 835                 count = -EFAULT;
 836                 goto done;
 837         }
 838
 839         if ((usblp->readcount += count) == avail) {
 840                 if (usblp_submit_read(usblp) < 0) {
 841                         /* We don't want to leak USB return codes into errno. */
 842                         if (count == 0)
 843                                 count = -EIO;
 844                         goto done;
 845                 }
 846         }
 847
 848 done:
 849         mutex_unlock(&usblp->mut);
 850         return count;
 851 }
 852
 853 /*
 854  * Wait for the write path to come idle.
 855  * This is called under the ->wmut, so the idle path stays idle.
 856  *
 857  * Our write path has a peculiar property: it does not buffer like a tty,
 858  * but waits for the write to succeed. This allows our ->release to bug out
 859  * without waiting for writes to drain. But it obviously does not work
 860  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 861  * select(2) or poll(2) to wait for the buffer to drain before closing.
 862  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 863  */
 864 static int usblp_wwait(struct usblp *usblp, int nonblock)
 865 {
 866         DECLARE_WAITQUEUE(waita, current);
 867         int rc;
 868         int err = 0;
 869
 870         add_wait_queue(&usblp->wwait, &waita);
 871         for (;;) {
 872                 if (mutex_lock_interruptible(&usblp->mut)) {
 873                         rc = -EINTR;
 874                         break;
 875                 }
 876                 set_current_state(TASK_INTERRUPTIBLE);
 877                 rc = usblp_wtest(usblp, nonblock);
 878                 mutex_unlock(&usblp->mut);
 879                 if (rc <= 0)
 880                         break;
 881
 882                 if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
 883                         if (usblp->flags & LP_ABORT) {
 884                                 err = usblp_check_status(usblp, err);
 885                                 if (err == 1) { /* Paper out */
 886                                         rc = -ENOSPC;
 887                                         break;
 888                                 }
 889                         } else {
 890                                 /* Prod the printer, Gentoo#251237. */
 891                                 mutex_lock(&usblp->mut);
 892                                 usblp_read_status(usblp, usblp->statusbuf);
 893                                 mutex_unlock(&usblp->mut);
 894                         }
 895                 }
 896         }
 897         set_current_state(TASK_RUNNING);
 898         remove_wait_queue(&usblp->wwait, &waita);
 899         return rc;
 900 }
 901
 902 static int usblp_wtest(struct usblp *usblp, int nonblock)
 903 {
 904         unsigned long flags;
 905
 906         if (!usblp->present)
 907                 return -ENODEV;
 908         if (signal_pending(current))
 909                 return -EINTR;
 910         spin_lock_irqsave(&usblp->lock, flags);
 911         if (usblp->wcomplete) {
 912                 spin_unlock_irqrestore(&usblp->lock, flags);
 913                 return 0;
 914         }
 915         spin_unlock_irqrestore(&usblp->lock, flags);
 916         if (nonblock)
 917                 return -EAGAIN;
 918         return 1;
 919 }
 920
 921 /*
 922  * Wait for read bytes to become available. This probably should have been
 923  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 924  * name for functions which lock and return.
 925  *
 926  * We do not use wait_event_interruptible because it makes locking iffy.
 927  */
 928 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 929 {
 930         DECLARE_WAITQUEUE(waita, current);
 931         int rc;
 932
 933         add_wait_queue(&usblp->rwait, &waita);
 934         for (;;) {
 935                 if (mutex_lock_interruptible(&usblp->mut)) {
 936                         rc = -EINTR;
 937                         break;
 938                 }
 939                 set_current_state(TASK_INTERRUPTIBLE);
 940                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 941                         mutex_unlock(&usblp->mut);
 942                         break;
 943                 }
 944                 if (rc == 0)    /* Keep it locked */
 945                         break;
 946                 mutex_unlock(&usblp->mut);
 947                 schedule();
 948         }
 949         set_current_state(TASK_RUNNING);
 950         remove_wait_queue(&usblp->rwait, &waita);
 951         return rc;
 952 }
 953
 954 static int usblp_rtest(struct usblp *usblp, int nonblock)
 955 {
 956         unsigned long flags;
 957
 958         if (!usblp->present)
 959                 return -ENODEV;
 960         if (signal_pending(current))
 961                 return -EINTR;
 962         spin_lock_irqsave(&usblp->lock, flags);
 963         if (usblp->rcomplete) {
 964                 spin_unlock_irqrestore(&usblp->lock, flags);
 965                 return 0;
 966         }
 967         spin_unlock_irqrestore(&usblp->lock, flags);
 968         if (nonblock)
 969                 return -EAGAIN;
 970         return 1;
 971 }
 972
 973 /*
 974  * Please check ->bidir and other such things outside for now.
 975  */
 976 static int usblp_submit_read(struct usblp *usblp)
 977 {
 978         struct urb *urb;
 979         unsigned long flags;
 980         int rc;
 981
 982         rc = -ENOMEM;
 983         urb = usb_alloc_urb(0, GFP_KERNEL);
 984         if (urb == NULL)
 985                 goto raise_urb;
 986
 987         usb_fill_bulk_urb(urb, usblp->dev,
 988                 usb_rcvbulkpipe(usblp->dev,
 989                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
 990                 usblp->readbuf, USBLP_BUF_SIZE_IN,
 991                 usblp_bulk_read, usblp);
 992         usb_anchor_urb(urb, &usblp->urbs);
 993
 994         spin_lock_irqsave(&usblp->lock, flags);
 995         usblp->readcount = 0; /* XXX Why here? */
 996         usblp->rcomplete = 0;
 997         spin_unlock_irqrestore(&usblp->lock, flags);
 998         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
 999                 dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1000                 spin_lock_irqsave(&usblp->lock, flags);
1001                 usblp->rstatus = rc;
1002                 usblp->rcomplete = 1;
1003                 spin_unlock_irqrestore(&usblp->lock, flags);
1004                 goto raise_submit;
1005         }
1006
1007         return 0;
1008
1009 raise_submit:
1010         usb_unanchor_urb(urb);
1011         usb_free_urb(urb);
1012 raise_urb:
1013         return rc;
1014 }
1015
1016 /*
1017  * Checks for printers that have quirks, such as requiring unidirectional
1018  * communication but reporting bidirectional; currently some HP printers
1019  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1020  * sent at each open (like some Epsons).
1021  * Returns 1 if found, 0 if not found.
1022  *
1023  * HP recommended that we use the bidirectional interface but
1024  * don't attempt any bulk IN transfers from the IN endpoint.
1025  * Here's some more detail on the problem:
1026  * The problem is not that it isn't bidirectional though. The problem
1027  * is that if you request a device ID, or status information, while
1028  * the buffers are full, the return data will end up in the print data
1029  * buffer. For example if you make sure you never request the device ID
1030  * while you are sending print data, and you don't try to query the
1031  * printer status every couple of milliseconds, you will probably be OK.
1032  */
1033 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1034 {
1035         int i;
1036
1037         for (i = 0; quirk_printers[i].vendorId; i++) {
1038                 if (vendor == quirk_printers[i].vendorId &&
1039                     product == quirk_printers[i].productId)
1040                         return quirk_printers[i].quirks;
1041         }
1042         return 0;
1043 }
1044
1045 static const struct file_operations usblp_fops = {
1046         .owner =        THIS_MODULE,
1047         .read =         usblp_read,
1048         .write =        usblp_write,
1049         .poll =         usblp_poll,
1050         .unlocked_ioctl =       usblp_ioctl,
1051         .compat_ioctl =         usblp_ioctl,
1052         .open =         usblp_open,
1053         .release =      usblp_release,
1054         .llseek =       noop_llseek,
1055 };
1056
1057 static char *usblp_devnode(struct device *dev, umode_t *mode)
1058 {
1059         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1060 }
1061
1062 static struct usb_class_driver usblp_class = {
1063         .name =         "lp%d",
1064         .devnode =      usblp_devnode,
1065         .fops =         &usblp_fops,
1066         .minor_base =   USBLP_MINOR_BASE,
1067 };
1068
1069 static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1070 {
1071         struct usb_interface *intf = to_usb_interface(dev);
1072         struct usblp *usblp = usb_get_intfdata(intf);
1073
1074         if (usblp->device_id_string[0] == 0 &&
1075             usblp->device_id_string[1] == 0)
1076                 return 0;
1077
1078         return sprintf(buf, "%s", usblp->device_id_string+2);
1079 }
1080
1081 static DEVICE_ATTR_RO(ieee1284_id);
1082
1083 static int usblp_probe(struct usb_interface *intf,
1084                        const struct usb_device_id *id)
1085 {
1086         struct usb_device *dev = interface_to_usbdev(intf);
1087         struct usblp *usblp;
1088         int protocol;
1089         int retval;
1090
1091         /* Malloc and start initializing usblp structure so we can use it
1092          * directly. */
1093         usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1094         if (!usblp) {
1095                 retval = -ENOMEM;
1096                 goto abort_ret;
1097         }
1098         usblp->dev = dev;
1099         mutex_init(&usblp->wmut);
1100         mutex_init(&usblp->mut);
1101         spin_lock_init(&usblp->lock);
1102         init_waitqueue_head(&usblp->rwait);
1103         init_waitqueue_head(&usblp->wwait);
1104         init_usb_anchor(&usblp->urbs);
1105         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1106         usblp->intf = intf;
1107
1108         /* Malloc device ID string buffer to the largest expected length,
1109          * since we can re-query it on an ioctl and a dynamic string
1110          * could change in length. */
1111         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1112                 retval = -ENOMEM;
1113                 goto abort;
1114         }
1115
1116         /*
1117          * Allocate read buffer. We somewhat wastefully
1118          * malloc both regardless of bidirectionality, because the
1119          * alternate setting can be changed later via an ioctl.
1120          */
1121         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1122                 retval = -ENOMEM;
1123                 goto abort;
1124         }
1125
1126         /* Allocate buffer for printer status */
1127         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1128         if (!usblp->statusbuf) {
1129                 retval = -ENOMEM;
1130                 goto abort;
1131         }
1132
1133         /* Lookup quirks for this printer. */
1134         usblp->quirks = usblp_quirks(
1135                 le16_to_cpu(dev->descriptor.idVendor),
1136                 le16_to_cpu(dev->descriptor.idProduct));
1137
1138         /* Analyze and pick initial alternate settings and endpoints. */
1139         protocol = usblp_select_alts(usblp);
1140         if (protocol < 0) {
1141                 dev_dbg(&intf->dev,
1142                         "incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1143                         le16_to_cpu(dev->descriptor.idVendor),
1144                         le16_to_cpu(dev->descriptor.idProduct));
1145                 retval = -ENODEV;
1146                 goto abort;
1147         }
1148
1149         /* Setup the selected alternate setting and endpoints. */
1150         if (usblp_set_protocol(usblp, protocol) < 0) {
1151                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1152                 goto abort;
1153         }
1154
1155         /* Retrieve and store the device ID string. */
1156         usblp_cache_device_id_string(usblp);
1157         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1158         if (retval)
1159                 goto abort_intfdata;
1160
1161 #ifdef DEBUG
1162         usblp_check_status(usblp, 0);
1163 #endif
1164
1165         usb_set_intfdata(intf, usblp);
1166
1167         usblp->present = 1;
1168
1169         retval = usb_register_dev(intf, &usblp_class);
1170         if (retval) {
1171                 dev_err(&intf->dev,
1172                         "usblp: Not able to get a minor (base %u, slice default): %d\n",
1173                         USBLP_MINOR_BASE, retval);
1174                 goto abort_intfdata;
1175         }
1176         usblp->minor = intf->minor;
1177         dev_info(&intf->dev,
1178                 "usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1179                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1180                 usblp->ifnum,
1181                 usblp->protocol[usblp->current_protocol].alt_setting,
1182                 usblp->current_protocol,
1183                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1184                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1185
1186         return 0;
1187
1188 abort_intfdata:
1189         usb_set_intfdata(intf, NULL);
1190         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1191 abort:
1192         kfree(usblp->readbuf);
1193         kfree(usblp->statusbuf);
1194         kfree(usblp->device_id_string);
1195         kfree(usblp);
1196 abort_ret:
1197         return retval;
1198 }
1199
1200 /*
1201  * We are a "new" style driver with usb_device_id table,
1202  * but our requirements are too intricate for simple match to handle.
1203  *
1204  * The "proto_bias" option may be used to specify the preferred protocol
1205  * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1206  * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1207  * then we bind to it.
1208  *
1209  * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1210  * is compatible with a stream of characters. If we find it, we bind to it.
1211  *
1212  * Note that the people from hpoj.sourceforge.net need to be able to
1213  * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1214  * for this purpose.
1215  *
1216  * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1217  * even though it's probably not stream-compatible, because this matches
1218  * the behaviour of the old code.
1219  *
1220  * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1221  * - the unidirectional interface.
1222  */
1223 static int usblp_select_alts(struct usblp *usblp)
1224 {
1225         struct usb_interface *if_alt;
1226         struct usb_host_interface *ifd;
1227         struct usb_endpoint_descriptor *epwrite, *epread;
1228         int p, i;
1229         int res;
1230
1231         if_alt = usblp->intf;
1232
1233         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1234                 usblp->protocol[p].alt_setting = -1;
1235
1236         /* Find out what we have. */
1237         for (i = 0; i < if_alt->num_altsetting; i++) {
1238                 ifd = &if_alt->altsetting[i];
1239
1240                 if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1241                     ifd->desc.bInterfaceSubClass != 1)
1242                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1243                                 continue;
1244
1245                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1246                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1247                         continue;
1248
1249                 /* Look for the expected bulk endpoints. */
1250                 if (ifd->desc.bInterfaceProtocol > 1) {
1251                         res = usb_find_common_endpoints(ifd,
1252                                         &epread, &epwrite, NULL, NULL);
1253                 } else {
1254                         epread = NULL;
1255                         res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1256                 }
1257
1258                 /* Ignore buggy hardware without the right endpoints. */
1259                 if (res)
1260                         continue;
1261
1262                 /* Turn off reads for buggy bidirectional printers. */
1263                 if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1264                         printk(KERN_INFO "usblp%d: Disabling reads from "
1265                             "problematic bidirectional printer\n",
1266                             usblp->minor);
1267                         epread = NULL;
1268                 }
1269
1270                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1271                                 ifd->desc.bAlternateSetting;
1272                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1273                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1274         }
1275
1276         /* If our requested protocol is supported, then use it. */
1277         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1278             proto_bias <= USBLP_LAST_PROTOCOL &&
1279             usblp->protocol[proto_bias].alt_setting != -1)
1280                 return proto_bias;
1281
1282         /* Ordering is important here. */
1283         if (usblp->protocol[2].alt_setting != -1)
1284                 return 2;
1285         if (usblp->protocol[1].alt_setting != -1)
1286                 return 1;
1287         if (usblp->protocol[3].alt_setting != -1)
1288                 return 3;
1289
1290         /* If nothing is available, then don't bind to this device. */
1291         return -1;
1292 }
1293
1294 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1295 {
1296         int r, alts;
1297
1298         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1299                 return -EINVAL;
1300
1301         alts = usblp->protocol[protocol].alt_setting;
1302         if (alts < 0)
1303                 return -EINVAL;
1304         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1305         if (r < 0) {
1306                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1307                         alts, usblp->ifnum);
1308                 return r;
1309         }
1310
1311         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1312         usblp->current_protocol = protocol;
1313         dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1314                 usblp->minor, protocol);
1315         return 0;
1316 }
1317
1318 /* Retrieves and caches device ID string.
1319  * Returns length, including length bytes but not null terminator.
1320  * On error, returns a negative errno value. */
1321 static int usblp_cache_device_id_string(struct usblp *usblp)
1322 {
1323         int err, length;
1324
1325         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1326         if (err < 0) {
1327                 dev_dbg(&usblp->intf->dev,
1328                         "usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1329                         usblp->minor, err);
1330                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1331                 return -EIO;
1332         }
1333
1334         /* First two bytes are length in big-endian.
1335          * They count themselves, and we copy them into
1336          * the user's buffer. */
1337         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1338         if (length < 2)
1339                 length = 2;
1340         else if (length >= USBLP_DEVICE_ID_SIZE)
1341                 length = USBLP_DEVICE_ID_SIZE - 1;
1342         usblp->device_id_string[length] = '\0';
1343
1344         dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1345                 usblp->minor, length, &usblp->device_id_string[2]);
1346
1347         return length;
1348 }
1349
1350 static void usblp_disconnect(struct usb_interface *intf)
1351 {
1352         struct usblp *usblp = usb_get_intfdata(intf);
1353
1354         usb_deregister_dev(intf, &usblp_class);
1355
1356         if (!usblp || !usblp->dev) {
1357                 dev_err(&intf->dev, "bogus disconnect\n");
1358                 BUG();
1359         }
1360
1361         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1362
1363         mutex_lock(&usblp_mutex);
1364         mutex_lock(&usblp->mut);
1365         usblp->present = 0;
1366         wake_up(&usblp->wwait);
1367         wake_up(&usblp->rwait);
1368         usb_set_intfdata(intf, NULL);
1369
1370         usblp_unlink_urbs(usblp);
1371         mutex_unlock(&usblp->mut);
1372
1373         if (!usblp->used)
1374                 usblp_cleanup(usblp);
1375         mutex_unlock(&usblp_mutex);
1376 }
1377
1378 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1379 {
1380         struct usblp *usblp = usb_get_intfdata(intf);
1381
1382         usblp_unlink_urbs(usblp);
1383 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1384         /* not strictly necessary, but just in case */
1385         wake_up(&usblp->wwait);
1386         wake_up(&usblp->rwait);
1387 #endif
1388
1389         return 0;
1390 }
1391
1392 static int usblp_resume(struct usb_interface *intf)
1393 {
1394         struct usblp *usblp = usb_get_intfdata(intf);
1395         int r;
1396
1397         r = handle_bidir(usblp);
1398
1399         return r;
1400 }
1401
1402 static const struct usb_device_id usblp_ids[] = {
1403         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1404         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1405         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1406         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1407         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1408         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1409         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1410         { }                                             /* Terminating entry */
1411 };
1412
1413 MODULE_DEVICE_TABLE(usb, usblp_ids);
1414
1415 static struct usb_driver usblp_driver = {
1416         .name =         "usblp",
1417         .probe =        usblp_probe,
1418         .disconnect =   usblp_disconnect,
1419         .suspend =      usblp_suspend,
1420         .resume =       usblp_resume,
1421         .id_table =     usblp_ids,
1422         .supports_autosuspend = 1,
1423 };
1424
1425 module_usb_driver(usblp_driver);
1426
1427 MODULE_AUTHOR(DRIVER_AUTHOR);
1428 MODULE_DESCRIPTION(DRIVER_DESC);
1429 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1430 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1431 MODULE_LICENSE("GPL");