drivers/usb/class/usblp.c

   1 /*
   2  * usblp.c
   3  *
   4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
   5  * Copyright (c) 1999 Pavel Machek      <pavel@suse.cz>
   6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
   7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
   8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
   9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
  10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
  11  *
  12  * USB Printer Device Class driver for USB printers and printer cables
  13  *
  14  * Sponsored by SuSE
  15  *
  16  * ChangeLog:
  17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
  18  *      v0.2 - some more cleanups
  19  *      v0.3 - cleaner again, waitqueue fixes
  20  *      v0.4 - fixes in unidirectional mode
  21  *      v0.5 - add DEVICE_ID string support
  22  *      v0.6 - never time out
  23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
  24  *      v0.8 - add devfs support
  25  *      v0.9 - fix unplug-while-open paths
  26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
  27  *      v0.11 - add proto_bias option (Pete Zaitcev)
  28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
  29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
  30  *              use usb_buffer_alloc() for read buf & write buf;
  31  */
  32
  33 /*
  34  * This program is free software; you can redistribute it and/or modify
  35  * it under the terms of the GNU General Public License as published by
  36  * the Free Software Foundation; either version 2 of the License, or
  37  * (at your option) any later version.
  38  *
  39  * This program is distributed in the hope that it will be useful,
  40  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  41  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  42  * GNU General Public License for more details.
  43  *
  44  * You should have received a copy of the GNU General Public License
  45  * along with this program; if not, write to the Free Software
  46  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  47  */
  48
  49 #include <linux/module.h>
  50 #include <linux/kernel.h>
  51 #include <linux/sched.h>
  52 #include <linux/signal.h>
  53 #include <linux/poll.h>
  54 #include <linux/init.h>
  55 #include <linux/slab.h>
  56 #include <linux/lp.h>
  57 #include <linux/mutex.h>
  58 #undef DEBUG
  59 #include <linux/usb.h>
  60
  61 /*
  62  * Version Information
  63  */
  64 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
  65 #define DRIVER_DESC "USB Printer Device Class driver"
  66
  67 #define USBLP_BUF_SIZE          8192
  68 #define USBLP_BUF_SIZE_IN       1024
  69 #define USBLP_DEVICE_ID_SIZE    1024
  70
  71 /* ioctls: */
  72 #define LPGETSTATUS             0x060b          /* same as in drivers/char/lp.c */
  73 #define IOCNR_GET_DEVICE_ID             1
  74 #define IOCNR_GET_PROTOCOLS             2
  75 #define IOCNR_SET_PROTOCOL              3
  76 #define IOCNR_HP_SET_CHANNEL            4
  77 #define IOCNR_GET_BUS_ADDRESS           5
  78 #define IOCNR_GET_VID_PID               6
  79 #define IOCNR_SOFT_RESET                7
  80 /* Get device_id string: */
  81 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
  82 /* The following ioctls were added for http://hpoj.sourceforge.net: */
  83 /* Get two-int array:
  84  * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
  85  * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
  86 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
  87 /* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
  88 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
  89 /* Set channel number (HP Vendor-specific command): */
  90 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
  91 /* Get two-int array: [0]=bus number, [1]=device address: */
  92 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
  93 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
  94 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
  95 /* Perform class specific soft reset */
  96 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
  97
  98 /*
  99  * A DEVICE_ID string may include the printer's serial number.
 100  * It should end with a semi-colon (';').
 101  * An example from an HP 970C DeskJet printer is (this is one long string,
 102  * with the serial number changed):
 103 MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
 104  */
 105
 106 /*
 107  * USB Printer Requests
 108  */
 109
 110 #define USBLP_REQ_GET_ID                        0x00
 111 #define USBLP_REQ_GET_STATUS                    0x01
 112 #define USBLP_REQ_RESET                         0x02
 113 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
 114
 115 #define USBLP_MINORS            16
 116 #define USBLP_MINOR_BASE        0
 117
 118 #define USBLP_WRITE_TIMEOUT     (5000)                  /* 5 seconds */
 119
 120 #define USBLP_FIRST_PROTOCOL    1
 121 #define USBLP_LAST_PROTOCOL     3
 122 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
 123
 124 /*
 125  * some arbitrary status buffer size;
 126  * need a status buffer that is allocated via kmalloc(), not on stack
 127  */
 128 #define STATUS_BUF_SIZE         8
 129
 130 /*
 131  * Locks down the locking order:
 132  * ->wmut locks wstatus.
 133  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
 134  * [rw]status. We only touch status when we know the side idle.
 135  * ->lock locks what interrupt accesses.
 136  */
 137 struct usblp {
 138         struct usb_device       *dev;                   /* USB device */
 139         struct mutex            wmut;
 140         struct mutex            mut;
 141         spinlock_t              lock;           /* locks rcomplete, wcomplete */
 142         char                    *readbuf;               /* read transfer_buffer */
 143         char                    *statusbuf;             /* status transfer_buffer */
 144         struct usb_anchor       urbs;
 145         wait_queue_head_t       rwait, wwait;
 146         int                     readcount;              /* Counter for reads */
 147         int                     ifnum;                  /* Interface number */
 148         struct usb_interface    *intf;                  /* The interface */
 149         /* Alternate-setting numbers and endpoints for each protocol
 150          * (7/1/{index=1,2,3}) that the device supports: */
 151         struct {
 152                 int                             alt_setting;
 153                 struct usb_endpoint_descriptor  *epwrite;
 154                 struct usb_endpoint_descriptor  *epread;
 155         }                       protocol[USBLP_MAX_PROTOCOLS];
 156         int                     current_protocol;
 157         int                     minor;                  /* minor number of device */
 158         int                     wcomplete, rcomplete;
 159         int                     wstatus;        /* bytes written or error */
 160         int                     rstatus;        /* bytes ready or error */
 161         unsigned int            quirks;                 /* quirks flags */
 162         unsigned char           used;                   /* True if open */
 163         unsigned char           present;                /* True if not disconnected */
 164         unsigned char           bidir;                  /* interface is bidirectional */
 165         unsigned char           sleeping;               /* interface is suspended */
 166         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
 167                                                         /* first 2 bytes are (big-endian) length */
 168 };
 169
 170 #ifdef DEBUG
 171 static void usblp_dump(struct usblp *usblp) {
 172         int p;
 173
 174         dbg("usblp=0x%p", usblp);
 175         dbg("dev=0x%p", usblp->dev);
 176         dbg("present=%d", usblp->present);
 177         dbg("readbuf=0x%p", usblp->readbuf);
 178         dbg("readcount=%d", usblp->readcount);
 179         dbg("ifnum=%d", usblp->ifnum);
 180     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
 181         dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
 182         dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
 183         dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
 184     }
 185         dbg("current_protocol=%d", usblp->current_protocol);
 186         dbg("minor=%d", usblp->minor);
 187         dbg("wstatus=%d", usblp->wstatus);
 188         dbg("rstatus=%d", usblp->rstatus);
 189         dbg("quirks=%d", usblp->quirks);
 190         dbg("used=%d", usblp->used);
 191         dbg("bidir=%d", usblp->bidir);
 192         dbg("sleeping=%d", usblp->sleeping);
 193         dbg("device_id_string=\"%s\"",
 194                 usblp->device_id_string ?
 195                         usblp->device_id_string + 2 :
 196                         (unsigned char *)"(null)");
 197 }
 198 #endif
 199
 200 /* Quirks: various printer quirks are handled by this table & its flags. */
 201
 202 struct quirk_printer_struct {
 203         __u16 vendorId;
 204         __u16 productId;
 205         unsigned int quirks;
 206 };
 207
 208 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
 209 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
 210 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
 211
 212 static const struct quirk_printer_struct quirk_printers[] = {
 213         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
 214         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
 215         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
 216         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
 217         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
 218         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
 219         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
 220         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
 221         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
 222         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
 223         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
 224         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
 225         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
 226         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
 227         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
 228         { 0, 0 }
 229 };
 230
 231 static int usblp_wwait(struct usblp *usblp, int nonblock);
 232 static int usblp_wtest(struct usblp *usblp, int nonblock);
 233 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
 234 static int usblp_rtest(struct usblp *usblp, int nonblock);
 235 static int usblp_submit_read(struct usblp *usblp);
 236 static int usblp_select_alts(struct usblp *usblp);
 237 static int usblp_set_protocol(struct usblp *usblp, int protocol);
 238 static int usblp_cache_device_id_string(struct usblp *usblp);
 239
 240 /* forward reference to make our lives easier */
 241 static struct usb_driver usblp_driver;
 242 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 243
 244 /*
 245  * Functions for usblp control messages.
 246  */
 247
 248 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
 249 {
 250         int retval;
 251         int index = usblp->ifnum;
 252
 253         /* High byte has the interface index.
 254            Low byte has the alternate setting.
 255          */
 256         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
 257           index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
 258         }
 259
 260         retval = usb_control_msg(usblp->dev,
 261                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
 262                 request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
 263         dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
 264                 request, !!dir, recip, value, index, len, retval);
 265         return retval < 0 ? retval : 0;
 266 }
 267
 268 #define usblp_read_status(usblp, status)\
 269         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
 270 #define usblp_get_id(usblp, config, id, maxlen)\
 271         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
 272 #define usblp_reset(usblp)\
 273         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
 274
 275 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
 276         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
 277
 278 /*
 279  * See the description for usblp_select_alts() below for the usage
 280  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
 281  * case of any trouble.
 282  */
 283 static int proto_bias = -1;
 284
 285 /*
 286  * URB callback.
 287  */
 288
 289 static void usblp_bulk_read(struct urb *urb)
 290 {
 291         struct usblp *usblp = urb->context;
 292         int status = urb->status;
 293
 294         if (usblp->present && usblp->used) {
 295                 if (status)
 296                         printk(KERN_WARNING "usblp%d: "
 297                             "nonzero read bulk status received: %d\n",
 298                             usblp->minor, status);
 299         }
 300         spin_lock(&usblp->lock);
 301         if (status < 0)
 302                 usblp->rstatus = status;
 303         else
 304                 usblp->rstatus = urb->actual_length;
 305         usblp->rcomplete = 1;
 306         wake_up(&usblp->rwait);
 307         spin_unlock(&usblp->lock);
 308
 309         usb_free_urb(urb);
 310 }
 311
 312 static void usblp_bulk_write(struct urb *urb)
 313 {
 314         struct usblp *usblp = urb->context;
 315         int status = urb->status;
 316
 317         if (usblp->present && usblp->used) {
 318                 if (status)
 319                         printk(KERN_WARNING "usblp%d: "
 320                             "nonzero write bulk status received: %d\n",
 321                             usblp->minor, status);
 322         }
 323         spin_lock(&usblp->lock);
 324         if (status < 0)
 325                 usblp->wstatus = status;
 326         else
 327                 usblp->wstatus = urb->actual_length;
 328         usblp->wcomplete = 1;
 329         wake_up(&usblp->wwait);
 330         spin_unlock(&usblp->lock);
 331
 332         /* XXX Use usb_setup_bulk_urb when available. Talk to Marcel. */
 333         kfree(urb->transfer_buffer);
 334         urb->transfer_buffer = NULL;    /* Not refcounted, so to be safe... */
 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         error = usblp_read_status (usblp, usblp->statusbuf);
 350         if (error < 0) {
 351                 if (printk_ratelimit())
 352                         printk(KERN_ERR
 353                                 "usblp%d: error %d reading printer status\n",
 354                                 usblp->minor, error);
 355                 return 0;
 356         }
 357
 358         status = *usblp->statusbuf;
 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 && !usblp->sleeping) {
 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         }
 405         usblp = usb_get_intfdata (intf);
 406         if (!usblp || !usblp->dev || !usblp->present)
 407                 goto out;
 408
 409         retval = -EBUSY;
 410         if (usblp->used)
 411                 goto out;
 412
 413         /*
 414          * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
 415          * This is #if 0-ed because we *don't* want to fail an open
 416          * just because the printer is off-line.
 417          */
 418 #if 0
 419         if ((retval = usblp_check_status(usblp, 0))) {
 420                 retval = retval > 1 ? -EIO : -ENOSPC;
 421                 goto out;
 422         }
 423 #else
 424         retval = 0;
 425 #endif
 426
 427         retval = usb_autopm_get_interface(intf);
 428         if (retval < 0)
 429                 goto out;
 430         usblp->used = 1;
 431         file->private_data = usblp;
 432
 433         usblp->wcomplete = 1; /* we begin writeable */
 434         usblp->wstatus = 0;
 435         usblp->rcomplete = 0;
 436
 437         if (handle_bidir(usblp) < 0) {
 438                 usblp->used = 0;
 439                 file->private_data = NULL;
 440                 retval = -EIO;
 441         }
 442 out:
 443         mutex_unlock (&usblp_mutex);
 444         return retval;
 445 }
 446
 447 static void usblp_cleanup (struct usblp *usblp)
 448 {
 449         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
 450
 451         kfree(usblp->readbuf);
 452         kfree (usblp->device_id_string);
 453         kfree (usblp->statusbuf);
 454         kfree (usblp);
 455 }
 456
 457 static void usblp_unlink_urbs(struct usblp *usblp)
 458 {
 459         usb_kill_anchored_urbs(&usblp->urbs);
 460 }
 461
 462 static int usblp_release(struct inode *inode, struct file *file)
 463 {
 464         struct usblp *usblp = file->private_data;
 465
 466         mutex_lock (&usblp_mutex);
 467         usblp->used = 0;
 468         if (usblp->present) {
 469                 usblp_unlink_urbs(usblp);
 470                 usb_autopm_put_interface(usblp->intf);
 471         } else          /* finish cleanup from disconnect */
 472                 usblp_cleanup (usblp);
 473         mutex_unlock (&usblp_mutex);
 474         return 0;
 475 }
 476
 477 /* No kernel lock - fine */
 478 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
 479 {
 480         int ret;
 481         unsigned long flags;
 482
 483         struct usblp *usblp = file->private_data;
 484         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
 485         poll_wait(file, &usblp->rwait, wait);
 486         poll_wait(file, &usblp->wwait, wait);
 487         spin_lock_irqsave(&usblp->lock, flags);
 488         ret = ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
 489                                | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
 490         spin_unlock_irqrestore(&usblp->lock, flags);
 491         return ret;
 492 }
 493
 494 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 495 {
 496         struct usblp *usblp = file->private_data;
 497         int length, err, i;
 498         unsigned char newChannel;
 499         int status;
 500         int twoints[2];
 501         int retval = 0;
 502
 503         mutex_lock (&usblp->mut);
 504         if (!usblp->present) {
 505                 retval = -ENODEV;
 506                 goto done;
 507         }
 508
 509         if (usblp->sleeping) {
 510                 retval = -ENODEV;
 511                 goto done;
 512         }
 513
 514         dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
 515                 _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
 516
 517         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 518
 519                 switch (_IOC_NR(cmd)) {
 520
 521                         case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 522                                 if (_IOC_DIR(cmd) != _IOC_READ) {
 523                                         retval = -EINVAL;
 524                                         goto done;
 525                                 }
 526
 527                                 length = usblp_cache_device_id_string(usblp);
 528                                 if (length < 0) {
 529                                         retval = length;
 530                                         goto done;
 531                                 }
 532                                 if (length > _IOC_SIZE(cmd))
 533                                         length = _IOC_SIZE(cmd); /* truncate */
 534
 535                                 if (copy_to_user((void __user *) arg,
 536                                                 usblp->device_id_string,
 537                                                 (unsigned long) length)) {
 538                                         retval = -EFAULT;
 539                                         goto done;
 540                                 }
 541
 542                                 break;
 543
 544                         case IOCNR_GET_PROTOCOLS:
 545                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 546                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 547                                         retval = -EINVAL;
 548                                         goto done;
 549                                 }
 550
 551                                 twoints[0] = usblp->current_protocol;
 552                                 twoints[1] = 0;
 553                                 for (i = USBLP_FIRST_PROTOCOL;
 554                                      i <= USBLP_LAST_PROTOCOL; i++) {
 555                                         if (usblp->protocol[i].alt_setting >= 0)
 556                                                 twoints[1] |= (1<<i);
 557                                 }
 558
 559                                 if (copy_to_user((void __user *)arg,
 560                                                 (unsigned char *)twoints,
 561                                                 sizeof(twoints))) {
 562                                         retval = -EFAULT;
 563                                         goto done;
 564                                 }
 565
 566                                 break;
 567
 568                         case IOCNR_SET_PROTOCOL:
 569                                 if (_IOC_DIR(cmd) != _IOC_WRITE) {
 570                                         retval = -EINVAL;
 571                                         goto done;
 572                                 }
 573
 574 #ifdef DEBUG
 575                                 if (arg == -10) {
 576                                         usblp_dump(usblp);
 577                                         break;
 578                                 }
 579 #endif
 580
 581                                 usblp_unlink_urbs(usblp);
 582                                 retval = usblp_set_protocol(usblp, arg);
 583                                 if (retval < 0) {
 584                                         usblp_set_protocol(usblp,
 585                                                 usblp->current_protocol);
 586                                 }
 587                                 break;
 588
 589                         case IOCNR_HP_SET_CHANNEL:
 590                                 if (_IOC_DIR(cmd) != _IOC_WRITE ||
 591                                     le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 592                                     usblp->quirks & USBLP_QUIRK_BIDIR) {
 593                                         retval = -EINVAL;
 594                                         goto done;
 595                                 }
 596
 597                                 err = usblp_hp_channel_change_request(usblp,
 598                                         arg, &newChannel);
 599                                 if (err < 0) {
 600                                         err("usblp%d: error = %d setting "
 601                                                 "HP channel",
 602                                                 usblp->minor, err);
 603                                         retval = -EIO;
 604                                         goto done;
 605                                 }
 606
 607                                 dbg("usblp%d requested/got HP channel %ld/%d",
 608                                         usblp->minor, arg, newChannel);
 609                                 break;
 610
 611                         case IOCNR_GET_BUS_ADDRESS:
 612                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 613                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 614                                         retval = -EINVAL;
 615                                         goto done;
 616                                 }
 617
 618                                 twoints[0] = usblp->dev->bus->busnum;
 619                                 twoints[1] = usblp->dev->devnum;
 620                                 if (copy_to_user((void __user *)arg,
 621                                                 (unsigned char *)twoints,
 622                                                 sizeof(twoints))) {
 623                                         retval = -EFAULT;
 624                                         goto done;
 625                                 }
 626
 627                                 dbg("usblp%d is bus=%d, device=%d",
 628                                         usblp->minor, twoints[0], twoints[1]);
 629                                 break;
 630
 631                         case IOCNR_GET_VID_PID:
 632                                 if (_IOC_DIR(cmd) != _IOC_READ ||
 633                                     _IOC_SIZE(cmd) < sizeof(twoints)) {
 634                                         retval = -EINVAL;
 635                                         goto done;
 636                                 }
 637
 638                                 twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 639                                 twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 640                                 if (copy_to_user((void __user *)arg,
 641                                                 (unsigned char *)twoints,
 642                                                 sizeof(twoints))) {
 643                                         retval = -EFAULT;
 644                                         goto done;
 645                                 }
 646
 647                                 dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
 648                                         usblp->minor, twoints[0], twoints[1]);
 649                                 break;
 650
 651                         case IOCNR_SOFT_RESET:
 652                                 if (_IOC_DIR(cmd) != _IOC_NONE) {
 653                                         retval = -EINVAL;
 654                                         goto done;
 655                                 }
 656                                 retval = usblp_reset(usblp);
 657                                 break;
 658                         default:
 659                                 retval = -ENOTTY;
 660                 }
 661         else    /* old-style ioctl value */
 662                 switch (cmd) {
 663
 664                         case LPGETSTATUS:
 665                                 if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
 666                                         if (printk_ratelimit())
 667                                                 printk(KERN_ERR "usblp%d:"
 668                                                     "failed reading printer status (%d)\n",
 669                                                     usblp->minor, retval);
 670                                         retval = -EIO;
 671                                         goto done;
 672                                 }
 673                                 status = *usblp->statusbuf;
 674                                 if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
 675                                         retval = -EFAULT;
 676                                 break;
 677
 678                         default:
 679                                 retval = -ENOTTY;
 680                 }
 681
 682 done:
 683         mutex_unlock (&usblp->mut);
 684         return retval;
 685 }
 686
 687 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 688 {
 689         struct usblp *usblp = file->private_data;
 690         char *writebuf;
 691         struct urb *writeurb;
 692         int rv;
 693         int transfer_length;
 694         ssize_t writecount = 0;
 695
 696         if (mutex_lock_interruptible(&usblp->wmut)) {
 697                 rv = -EINTR;
 698                 goto raise_biglock;
 699         }
 700         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 701                 goto raise_wait;
 702
 703         while (writecount < count) {
 704                 /*
 705                  * Step 1: Submit next block.
 706                  */
 707                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 708                         transfer_length = USBLP_BUF_SIZE;
 709
 710                 rv = -ENOMEM;
 711                 if ((writebuf = kmalloc(USBLP_BUF_SIZE, GFP_KERNEL)) == NULL)
 712                         goto raise_buf;
 713                 if ((writeurb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
 714                         goto raise_urb;
 715                 usb_fill_bulk_urb(writeurb, usblp->dev,
 716                         usb_sndbulkpipe(usblp->dev,
 717                           usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 718                         writebuf, transfer_length, usblp_bulk_write, usblp);
 719                 usb_anchor_urb(writeurb, &usblp->urbs);
 720
 721                 if (copy_from_user(writebuf,
 722                                    buffer + writecount, transfer_length)) {
 723                         rv = -EFAULT;
 724                         goto raise_badaddr;
 725                 }
 726
 727                 spin_lock_irq(&usblp->lock);
 728                 usblp->wcomplete = 0;
 729                 spin_unlock_irq(&usblp->lock);
 730                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 731                         usblp->wstatus = 0;
 732                         spin_lock_irq(&usblp->lock);
 733                         usblp->wcomplete = 1;
 734                         wake_up(&usblp->wwait);
 735                         spin_unlock_irq(&usblp->lock);
 736                         if (rv != -ENOMEM)
 737                                 rv = -EIO;
 738                         goto raise_submit;
 739                 }
 740
 741                 /*
 742                  * Step 2: Wait for transfer to end, collect results.
 743                  */
 744                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 745                 if (rv < 0) {
 746                         if (rv == -EAGAIN) {
 747                                 /* Presume that it's going to complete well. */
 748                                 writecount += transfer_length;
 749                         }
 750                         /* Leave URB dangling, to be cleaned on close. */
 751                         goto collect_error;
 752                 }
 753
 754                 if (usblp->wstatus < 0) {
 755                         usblp_check_status(usblp, 0);
 756                         rv = -EIO;
 757                         goto collect_error;
 758                 }
 759                 /*
 760                  * This is critical: it must be our URB, not other writer's.
 761                  * The wmut exists mainly to cover us here.
 762                  */
 763                 writecount += usblp->wstatus;
 764         }
 765
 766         mutex_unlock(&usblp->wmut);
 767         return writecount;
 768
 769 raise_submit:
 770 raise_badaddr:
 771         usb_unanchor_urb(writeurb);
 772         usb_free_urb(writeurb);
 773 raise_urb:
 774         kfree(writebuf);
 775 raise_buf:
 776 raise_wait:
 777 collect_error:          /* Out of raise sequence */
 778         mutex_unlock(&usblp->wmut);
 779 raise_biglock:
 780         return writecount ? writecount : rv;
 781 }
 782
 783 /*
 784  * Notice that we fail to restart in a few cases: on EFAULT, on restart
 785  * error, etc. This is the historical behaviour. In all such cases we return
 786  * EIO, and applications loop in order to get the new read going.
 787  */
 788 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 789 {
 790         struct usblp *usblp = file->private_data;
 791         ssize_t count;
 792         ssize_t avail;
 793         int rv;
 794
 795         if (!usblp->bidir)
 796                 return -EINVAL;
 797
 798         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 799         if (rv < 0)
 800                 return rv;
 801
 802         if ((avail = usblp->rstatus) < 0) {
 803                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 804                     usblp->minor, (int)avail);
 805                 usblp_submit_read(usblp);
 806                 count = -EIO;
 807                 goto done;
 808         }
 809
 810         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 811         if (count != 0 &&
 812             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 813                 count = -EFAULT;
 814                 goto done;
 815         }
 816
 817         if ((usblp->readcount += count) == avail) {
 818                 if (usblp_submit_read(usblp) < 0) {
 819                         /* We don't want to leak USB return codes into errno. */
 820                         if (count == 0)
 821                                 count = -EIO;
 822                         goto done;
 823                 }
 824         }
 825
 826 done:
 827         mutex_unlock (&usblp->mut);
 828         return count;
 829 }
 830
 831 /*
 832  * Wait for the write path to come idle.
 833  * This is called under the ->wmut, so the idle path stays idle.
 834  *
 835  * Our write path has a peculiar property: it does not buffer like a tty,
 836  * but waits for the write to succeed. This allows our ->release to bug out
 837  * without waiting for writes to drain. But it obviously does not work
 838  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 839  * select(2) or poll(2) to wait for the buffer to drain before closing.
 840  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 841  *
 842  * Old v0.13 code had a non-functional timeout for wait_event(). Someone forgot
 843  * to check the return code for timeout expiration, so it had no effect.
 844  * Apparently, it was intended to check for error conditons, such as out
 845  * of paper. It is going to return when we settle things with CUPS. XXX
 846  */
 847 static int usblp_wwait(struct usblp *usblp, int nonblock)
 848 {
 849         DECLARE_WAITQUEUE(waita, current);
 850         int rc;
 851
 852         add_wait_queue(&usblp->wwait, &waita);
 853         for (;;) {
 854                 if (mutex_lock_interruptible(&usblp->mut)) {
 855                         rc = -EINTR;
 856                         break;
 857                 }
 858                 set_current_state(TASK_INTERRUPTIBLE);
 859                 if ((rc = usblp_wtest(usblp, nonblock)) < 0) {
 860                         mutex_unlock(&usblp->mut);
 861                         break;
 862                 }
 863                 mutex_unlock(&usblp->mut);
 864                 if (rc == 0)
 865                         break;
 866                 schedule();
 867         }
 868         set_current_state(TASK_RUNNING);
 869         remove_wait_queue(&usblp->wwait, &waita);
 870         return rc;
 871 }
 872
 873 static int usblp_wtest(struct usblp *usblp, int nonblock)
 874 {
 875         unsigned long flags;
 876
 877         if (!usblp->present)
 878                 return -ENODEV;
 879         if (signal_pending(current))
 880                 return -EINTR;
 881         spin_lock_irqsave(&usblp->lock, flags);
 882         if (usblp->wcomplete) {
 883                 spin_unlock_irqrestore(&usblp->lock, flags);
 884                 return 0;
 885         }
 886         spin_unlock_irqrestore(&usblp->lock, flags);
 887         if (usblp->sleeping)
 888                 return -ENODEV;
 889         if (nonblock)
 890                 return -EAGAIN;
 891         return 1;
 892 }
 893
 894 /*
 895  * Wait for read bytes to become available. This probably should have been
 896  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 897  * name for functions which lock and return.
 898  *
 899  * We do not use wait_event_interruptible because it makes locking iffy.
 900  */
 901 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 902 {
 903         DECLARE_WAITQUEUE(waita, current);
 904         int rc;
 905
 906         add_wait_queue(&usblp->rwait, &waita);
 907         for (;;) {
 908                 if (mutex_lock_interruptible(&usblp->mut)) {
 909                         rc = -EINTR;
 910                         break;
 911                 }
 912                 set_current_state(TASK_INTERRUPTIBLE);
 913                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 914                         mutex_unlock(&usblp->mut);
 915                         break;
 916                 }
 917                 if (rc == 0)    /* Keep it locked */
 918                         break;
 919                 mutex_unlock(&usblp->mut);
 920                 schedule();
 921         }
 922         set_current_state(TASK_RUNNING);
 923         remove_wait_queue(&usblp->rwait, &waita);
 924         return rc;
 925 }
 926
 927 static int usblp_rtest(struct usblp *usblp, int nonblock)
 928 {
 929         unsigned long flags;
 930
 931         if (!usblp->present)
 932                 return -ENODEV;
 933         if (signal_pending(current))
 934                 return -EINTR;
 935         spin_lock_irqsave(&usblp->lock, flags);
 936         if (usblp->rcomplete) {
 937                 spin_unlock_irqrestore(&usblp->lock, flags);
 938                 return 0;
 939         }
 940         spin_unlock_irqrestore(&usblp->lock, flags);
 941         if (usblp->sleeping)
 942                 return -ENODEV;
 943         if (nonblock)
 944                 return -EAGAIN;
 945         return 1;
 946 }
 947
 948 /*
 949  * Please check ->bidir and other such things outside for now.
 950  */
 951 static int usblp_submit_read(struct usblp *usblp)
 952 {
 953         struct urb *urb;
 954         unsigned long flags;
 955         int rc;
 956
 957         rc = -ENOMEM;
 958         if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
 959                 goto raise_urb;
 960
 961         usb_fill_bulk_urb(urb, usblp->dev,
 962                 usb_rcvbulkpipe(usblp->dev,
 963                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
 964                 usblp->readbuf, USBLP_BUF_SIZE_IN,
 965                 usblp_bulk_read, usblp);
 966         usb_anchor_urb(urb, &usblp->urbs);
 967
 968         spin_lock_irqsave(&usblp->lock, flags);
 969         usblp->readcount = 0; /* XXX Why here? */
 970         usblp->rcomplete = 0;
 971         spin_unlock_irqrestore(&usblp->lock, flags);
 972         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
 973                 dbg("error submitting urb (%d)", rc);
 974                 spin_lock_irqsave(&usblp->lock, flags);
 975                 usblp->rstatus = rc;
 976                 usblp->rcomplete = 1;
 977                 spin_unlock_irqrestore(&usblp->lock, flags);
 978                 goto raise_submit;
 979         }
 980
 981         return 0;
 982
 983 raise_submit:
 984         usb_unanchor_urb(urb);
 985         usb_free_urb(urb);
 986 raise_urb:
 987         return rc;
 988 }
 989
 990 /*
 991  * Checks for printers that have quirks, such as requiring unidirectional
 992  * communication but reporting bidirectional; currently some HP printers
 993  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
 994  * sent at each open (like some Epsons).
 995  * Returns 1 if found, 0 if not found.
 996  *
 997  * HP recommended that we use the bidirectional interface but
 998  * don't attempt any bulk IN transfers from the IN endpoint.
 999  * Here's some more detail on the problem:
1000  * The problem is not that it isn't bidirectional though. The problem
1001  * is that if you request a device ID, or status information, while
1002  * the buffers are full, the return data will end up in the print data
1003  * buffer. For example if you make sure you never request the device ID
1004  * while you are sending print data, and you don't try to query the
1005  * printer status every couple of milliseconds, you will probably be OK.
1006  */
1007 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
1008 {
1009         int i;
1010
1011         for (i = 0; quirk_printers[i].vendorId; i++) {
1012                 if (vendor == quirk_printers[i].vendorId &&
1013                     product == quirk_printers[i].productId)
1014                         return quirk_printers[i].quirks;
1015         }
1016         return 0;
1017 }
1018
1019 static const struct file_operations usblp_fops = {
1020         .owner =        THIS_MODULE,
1021         .read =         usblp_read,
1022         .write =        usblp_write,
1023         .poll =         usblp_poll,
1024         .unlocked_ioctl =       usblp_ioctl,
1025         .compat_ioctl =         usblp_ioctl,
1026         .open =         usblp_open,
1027         .release =      usblp_release,
1028 };
1029
1030 static struct usb_class_driver usblp_class = {
1031         .name =         "lp%d",
1032         .fops =         &usblp_fops,
1033         .minor_base =   USBLP_MINOR_BASE,
1034 };
1035
1036 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1037 {
1038         struct usb_interface *intf = to_usb_interface(dev);
1039         struct usblp *usblp = usb_get_intfdata (intf);
1040
1041         if (usblp->device_id_string[0] == 0 &&
1042             usblp->device_id_string[1] == 0)
1043                 return 0;
1044
1045         return sprintf(buf, "%s", usblp->device_id_string+2);
1046 }
1047
1048 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1049
1050 static int usblp_probe(struct usb_interface *intf,
1051                        const struct usb_device_id *id)
1052 {
1053         struct usb_device *dev = interface_to_usbdev (intf);
1054         struct usblp *usblp = NULL;
1055         int protocol;
1056         int retval;
1057
1058         /* Malloc and start initializing usblp structure so we can use it
1059          * directly. */
1060         if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
1061                 retval = -ENOMEM;
1062                 goto abort;
1063         }
1064         usblp->dev = dev;
1065         mutex_init(&usblp->wmut);
1066         mutex_init (&usblp->mut);
1067         spin_lock_init(&usblp->lock);
1068         init_waitqueue_head(&usblp->rwait);
1069         init_waitqueue_head(&usblp->wwait);
1070         init_usb_anchor(&usblp->urbs);
1071         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1072         usblp->intf = intf;
1073
1074         /* Malloc device ID string buffer to the largest expected length,
1075          * since we can re-query it on an ioctl and a dynamic string
1076          * could change in length. */
1077         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1078                 retval = -ENOMEM;
1079                 goto abort;
1080         }
1081
1082         /*
1083          * Allocate read buffer. We somewhat wastefully
1084          * malloc both regardless of bidirectionality, because the
1085          * alternate setting can be changed later via an ioctl.
1086          */
1087         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1088                 retval = -ENOMEM;
1089                 goto abort;
1090         }
1091
1092         /* Allocate buffer for printer status */
1093         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1094         if (!usblp->statusbuf) {
1095                 retval = -ENOMEM;
1096                 goto abort;
1097         }
1098
1099         /* Lookup quirks for this printer. */
1100         usblp->quirks = usblp_quirks(
1101                 le16_to_cpu(dev->descriptor.idVendor),
1102                 le16_to_cpu(dev->descriptor.idProduct));
1103
1104         /* Analyze and pick initial alternate settings and endpoints. */
1105         protocol = usblp_select_alts(usblp);
1106         if (protocol < 0) {
1107                 dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1108                         le16_to_cpu(dev->descriptor.idVendor),
1109                         le16_to_cpu(dev->descriptor.idProduct));
1110                 retval = -ENODEV;
1111                 goto abort;
1112         }
1113
1114         /* Setup the selected alternate setting and endpoints. */
1115         if (usblp_set_protocol(usblp, protocol) < 0) {
1116                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1117                 goto abort;
1118         }
1119
1120         /* Retrieve and store the device ID string. */
1121         usblp_cache_device_id_string(usblp);
1122         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1123         if (retval)
1124                 goto abort_intfdata;
1125
1126 #ifdef DEBUG
1127         usblp_check_status(usblp, 0);
1128 #endif
1129
1130         usb_set_intfdata (intf, usblp);
1131
1132         usblp->present = 1;
1133
1134         retval = usb_register_dev(intf, &usblp_class);
1135         if (retval) {
1136                 printk(KERN_ERR "usblp: Not able to get a minor"
1137                     " (base %u, slice default): %d\n",
1138                     USBLP_MINOR_BASE, retval);
1139                 goto abort_intfdata;
1140         }
1141         usblp->minor = intf->minor;
1142         printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1143                 "if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1144                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1145                 usblp->ifnum,
1146                 usblp->protocol[usblp->current_protocol].alt_setting,
1147                 usblp->current_protocol,
1148                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1149                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1150
1151         return 0;
1152
1153 abort_intfdata:
1154         usb_set_intfdata (intf, NULL);
1155         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1156 abort:
1157         if (usblp) {
1158                 kfree(usblp->readbuf);
1159                 kfree(usblp->statusbuf);
1160                 kfree(usblp->device_id_string);
1161                 kfree(usblp);
1162         }
1163         return retval;
1164 }
1165
1166 /*
1167  * We are a "new" style driver with usb_device_id table,
1168  * but our requirements are too intricate for simple match to handle.
1169  *
1170  * The "proto_bias" option may be used to specify the preferred protocol
1171  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1172  * supports the preferred protocol, then we bind to it.
1173  *
1174  * The best interface for us is 7/1/2, because it is compatible
1175  * with a stream of characters. If we find it, we bind to it.
1176  *
1177  * Note that the people from hpoj.sourceforge.net need to be able to
1178  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1179  *
1180  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1181  * stream-compatible, because this matches the behaviour of the old code.
1182  *
1183  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1184  */
1185 static int usblp_select_alts(struct usblp *usblp)
1186 {
1187         struct usb_interface *if_alt;
1188         struct usb_host_interface *ifd;
1189         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1190         int p, i, e;
1191
1192         if_alt = usblp->intf;
1193
1194         for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1195                 usblp->protocol[p].alt_setting = -1;
1196
1197         /* Find out what we have. */
1198         for (i = 0; i < if_alt->num_altsetting; i++) {
1199                 ifd = &if_alt->altsetting[i];
1200
1201                 if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1202                         if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1203                                 continue;
1204
1205                 if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1206                     ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1207                         continue;
1208
1209                 /* Look for bulk OUT and IN endpoints. */
1210                 epwrite = epread = NULL;
1211                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1212                         epd = &ifd->endpoint[e].desc;
1213
1214                         if (usb_endpoint_is_bulk_out(epd))
1215                                 if (!epwrite)
1216                                         epwrite = epd;
1217
1218                         if (usb_endpoint_is_bulk_in(epd))
1219                                 if (!epread)
1220                                         epread = epd;
1221                 }
1222
1223                 /* Ignore buggy hardware without the right endpoints. */
1224                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1225                         continue;
1226
1227                 /* Turn off reads for 7/1/1 (unidirectional) interfaces
1228                  * and buggy bidirectional printers. */
1229                 if (ifd->desc.bInterfaceProtocol == 1) {
1230                         epread = NULL;
1231                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1232                         printk(KERN_INFO "usblp%d: Disabling reads from "
1233                             "problematic bidirectional printer\n",
1234                             usblp->minor);
1235                         epread = NULL;
1236                 }
1237
1238                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1239                                 ifd->desc.bAlternateSetting;
1240                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1241                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1242         }
1243
1244         /* If our requested protocol is supported, then use it. */
1245         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1246             proto_bias <= USBLP_LAST_PROTOCOL &&
1247             usblp->protocol[proto_bias].alt_setting != -1)
1248                 return proto_bias;
1249
1250         /* Ordering is important here. */
1251         if (usblp->protocol[2].alt_setting != -1)
1252                 return 2;
1253         if (usblp->protocol[1].alt_setting != -1)
1254                 return 1;
1255         if (usblp->protocol[3].alt_setting != -1)
1256                 return 3;
1257
1258         /* If nothing is available, then don't bind to this device. */
1259         return -1;
1260 }
1261
1262 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1263 {
1264         int r, alts;
1265
1266         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1267                 return -EINVAL;
1268
1269         alts = usblp->protocol[protocol].alt_setting;
1270         if (alts < 0)
1271                 return -EINVAL;
1272         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1273         if (r < 0) {
1274                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1275                         alts, usblp->ifnum);
1276                 return r;
1277         }
1278
1279         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1280         usblp->current_protocol = protocol;
1281         dbg("usblp%d set protocol %d", usblp->minor, protocol);
1282         return 0;
1283 }
1284
1285 /* Retrieves and caches device ID string.
1286  * Returns length, including length bytes but not null terminator.
1287  * On error, returns a negative errno value. */
1288 static int usblp_cache_device_id_string(struct usblp *usblp)
1289 {
1290         int err, length;
1291
1292         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1293         if (err < 0) {
1294                 dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1295                         usblp->minor, err);
1296                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1297                 return -EIO;
1298         }
1299
1300         /* First two bytes are length in big-endian.
1301          * They count themselves, and we copy them into
1302          * the user's buffer. */
1303         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1304         if (length < 2)
1305                 length = 2;
1306         else if (length >= USBLP_DEVICE_ID_SIZE)
1307                 length = USBLP_DEVICE_ID_SIZE - 1;
1308         usblp->device_id_string[length] = '\0';
1309
1310         dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1311                 usblp->minor, length, &usblp->device_id_string[2]);
1312
1313         return length;
1314 }
1315
1316 static void usblp_disconnect(struct usb_interface *intf)
1317 {
1318         struct usblp *usblp = usb_get_intfdata (intf);
1319
1320         usb_deregister_dev(intf, &usblp_class);
1321
1322         if (!usblp || !usblp->dev) {
1323                 err("bogus disconnect");
1324                 BUG ();
1325         }
1326
1327         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1328
1329         mutex_lock (&usblp_mutex);
1330         mutex_lock (&usblp->mut);
1331         usblp->present = 0;
1332         wake_up(&usblp->wwait);
1333         wake_up(&usblp->rwait);
1334         usb_set_intfdata (intf, NULL);
1335
1336         usblp_unlink_urbs(usblp);
1337         mutex_unlock (&usblp->mut);
1338
1339         if (!usblp->used)
1340                 usblp_cleanup (usblp);
1341         mutex_unlock (&usblp_mutex);
1342 }
1343
1344 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1345 {
1346         struct usblp *usblp = usb_get_intfdata (intf);
1347
1348         /* we take no more IO */
1349         usblp->sleeping = 1;
1350         usblp_unlink_urbs(usblp);
1351 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1352         /* not strictly necessary, but just in case */
1353         wake_up(&usblp->wwait);
1354         wake_up(&usblp->rwait);
1355 #endif
1356
1357         return 0;
1358 }
1359
1360 static int usblp_resume (struct usb_interface *intf)
1361 {
1362         struct usblp *usblp = usb_get_intfdata (intf);
1363         int r;
1364
1365         usblp->sleeping = 0;
1366         r = handle_bidir (usblp);
1367
1368         return r;
1369 }
1370
1371 static struct usb_device_id usblp_ids [] = {
1372         { USB_DEVICE_INFO(7, 1, 1) },
1373         { USB_DEVICE_INFO(7, 1, 2) },
1374         { USB_DEVICE_INFO(7, 1, 3) },
1375         { USB_INTERFACE_INFO(7, 1, 1) },
1376         { USB_INTERFACE_INFO(7, 1, 2) },
1377         { USB_INTERFACE_INFO(7, 1, 3) },
1378         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1379         { }                                             /* Terminating entry */
1380 };
1381
1382 MODULE_DEVICE_TABLE (usb, usblp_ids);
1383
1384 static struct usb_driver usblp_driver = {
1385         .name =         "usblp",
1386         .probe =        usblp_probe,
1387         .disconnect =   usblp_disconnect,
1388         .suspend =      usblp_suspend,
1389         .resume =       usblp_resume,
1390         .id_table =     usblp_ids,
1391         .supports_autosuspend = 1,
1392 };
1393
1394 static int __init usblp_init(void)
1395 {
1396         return usb_register(&usblp_driver);
1397 }
1398
1399 static void __exit usblp_exit(void)
1400 {
1401         usb_deregister(&usblp_driver);
1402 }
1403
1404 module_init(usblp_init);
1405 module_exit(usblp_exit);
1406
1407 MODULE_AUTHOR( DRIVER_AUTHOR );
1408 MODULE_DESCRIPTION( DRIVER_DESC );
1409 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1410 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1411 MODULE_LICENSE("GPL");