linux/drivers/usb/class/usblp.c
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   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):
  97MFG: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 */
 131struct 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
 168static 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
 203struct 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
 213static 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
 233static int usblp_wwait(struct usblp *usblp, int nonblock);
 234static int usblp_wtest(struct usblp *usblp, int nonblock);
 235static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
 236static int usblp_rtest(struct usblp *usblp, int nonblock);
 237static int usblp_submit_read(struct usblp *usblp);
 238static int usblp_select_alts(struct usblp *usblp);
 239static int usblp_set_protocol(struct usblp *usblp, int protocol);
 240static int usblp_cache_device_id_string(struct usblp *usblp);
 241
 242/* forward reference to make our lives easier */
 243static struct usb_driver usblp_driver;
 244static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
 245
 246/*
 247 * Functions for usblp control messages.
 248 */
 249
 250static 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 */
 285static int proto_bias = -1;
 286
 287/*
 288 * URB callback.
 289 */
 290
 291static void usblp_bulk_read(struct urb *urb)
 292{
 293        struct usblp *usblp = urb->context;
 294        int status = urb->status;
 295        unsigned long flags;
 296
 297        if (usblp->present && usblp->used) {
 298                if (status)
 299                        printk(KERN_WARNING "usblp%d: "
 300                            "nonzero read bulk status received: %d\n",
 301                            usblp->minor, status);
 302        }
 303        spin_lock_irqsave(&usblp->lock, flags);
 304        if (status < 0)
 305                usblp->rstatus = status;
 306        else
 307                usblp->rstatus = urb->actual_length;
 308        usblp->rcomplete = 1;
 309        wake_up(&usblp->rwait);
 310        spin_unlock_irqrestore(&usblp->lock, flags);
 311
 312        usb_free_urb(urb);
 313}
 314
 315static void usblp_bulk_write(struct urb *urb)
 316{
 317        struct usblp *usblp = urb->context;
 318        int status = urb->status;
 319        unsigned long flags;
 320
 321        if (usblp->present && usblp->used) {
 322                if (status)
 323                        printk(KERN_WARNING "usblp%d: "
 324                            "nonzero write bulk status received: %d\n",
 325                            usblp->minor, status);
 326        }
 327        spin_lock_irqsave(&usblp->lock, flags);
 328        if (status < 0)
 329                usblp->wstatus = status;
 330        else
 331                usblp->wstatus = urb->actual_length;
 332        usblp->no_paper = 0;
 333        usblp->wcomplete = 1;
 334        wake_up(&usblp->wwait);
 335        spin_unlock_irqrestore(&usblp->lock, flags);
 336
 337        usb_free_urb(urb);
 338}
 339
 340/*
 341 * Get and print printer errors.
 342 */
 343
 344static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
 345
 346static int usblp_check_status(struct usblp *usblp, int err)
 347{
 348        unsigned char status, newerr = 0;
 349        int error;
 350
 351        mutex_lock(&usblp->mut);
 352        if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
 353                mutex_unlock(&usblp->mut);
 354                printk_ratelimited(KERN_ERR
 355                                "usblp%d: error %d reading printer status\n",
 356                                usblp->minor, error);
 357                return 0;
 358        }
 359        status = *usblp->statusbuf;
 360        mutex_unlock(&usblp->mut);
 361
 362        if (~status & LP_PERRORP)
 363                newerr = 3;
 364        if (status & LP_POUTPA)
 365                newerr = 1;
 366        if (~status & LP_PSELECD)
 367                newerr = 2;
 368
 369        if (newerr != err) {
 370                printk(KERN_INFO "usblp%d: %s\n",
 371                   usblp->minor, usblp_messages[newerr]);
 372        }
 373
 374        return newerr;
 375}
 376
 377static int handle_bidir(struct usblp *usblp)
 378{
 379        if (usblp->bidir && usblp->used) {
 380                if (usblp_submit_read(usblp) < 0)
 381                        return -EIO;
 382        }
 383        return 0;
 384}
 385
 386/*
 387 * File op functions.
 388 */
 389
 390static int usblp_open(struct inode *inode, struct file *file)
 391{
 392        int minor = iminor(inode);
 393        struct usblp *usblp;
 394        struct usb_interface *intf;
 395        int retval;
 396
 397        if (minor < 0)
 398                return -ENODEV;
 399
 400        mutex_lock(&usblp_mutex);
 401
 402        retval = -ENODEV;
 403        intf = usb_find_interface(&usblp_driver, minor);
 404        if (!intf)
 405                goto out;
 406        usblp = usb_get_intfdata(intf);
 407        if (!usblp || !usblp->dev || !usblp->present)
 408                goto out;
 409
 410        retval = -EBUSY;
 411        if (usblp->used)
 412                goto out;
 413
 414        /*
 415         * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
 416         *  - We do not want persistent state which close(2) does not clear
 417         *  - It is not used anyway, according to CUPS people
 418         */
 419
 420        retval = usb_autopm_get_interface(intf);
 421        if (retval < 0)
 422                goto out;
 423        usblp->used = 1;
 424        file->private_data = usblp;
 425
 426        usblp->wcomplete = 1; /* we begin writeable */
 427        usblp->wstatus = 0;
 428        usblp->rcomplete = 0;
 429
 430        if (handle_bidir(usblp) < 0) {
 431                usb_autopm_put_interface(intf);
 432                usblp->used = 0;
 433                file->private_data = NULL;
 434                retval = -EIO;
 435        }
 436out:
 437        mutex_unlock(&usblp_mutex);
 438        return retval;
 439}
 440
 441static void usblp_cleanup(struct usblp *usblp)
 442{
 443        printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
 444
 445        kfree(usblp->readbuf);
 446        kfree(usblp->device_id_string);
 447        kfree(usblp->statusbuf);
 448        usb_put_intf(usblp->intf);
 449        kfree(usblp);
 450}
 451
 452static void usblp_unlink_urbs(struct usblp *usblp)
 453{
 454        usb_kill_anchored_urbs(&usblp->urbs);
 455}
 456
 457static int usblp_release(struct inode *inode, struct file *file)
 458{
 459        struct usblp *usblp = file->private_data;
 460
 461        usblp->flags &= ~LP_ABORT;
 462
 463        mutex_lock(&usblp_mutex);
 464        usblp->used = 0;
 465        if (usblp->present)
 466                usblp_unlink_urbs(usblp);
 467
 468        usb_autopm_put_interface(usblp->intf);
 469
 470        if (!usblp->present)            /* finish cleanup from disconnect */
 471                usblp_cleanup(usblp);   /* any URBs must be dead */
 472
 473        mutex_unlock(&usblp_mutex);
 474        return 0;
 475}
 476
 477/* No kernel lock - fine */
 478static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
 479{
 480        __poll_t 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) ? EPOLLIN  | EPOLLRDNORM : 0) |
 489           ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 0);
 490        spin_unlock_irqrestore(&usblp->lock, flags);
 491        return ret;
 492}
 493
 494static 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        dev_dbg(&usblp->intf->dev,
 510                "usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
 511                _IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
 512
 513        if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
 514
 515                switch (_IOC_NR(cmd)) {
 516
 517                case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 518                        if (_IOC_DIR(cmd) != _IOC_READ) {
 519                                retval = -EINVAL;
 520                                goto done;
 521                        }
 522
 523                        length = usblp_cache_device_id_string(usblp);
 524                        if (length < 0) {
 525                                retval = length;
 526                                goto done;
 527                        }
 528                        if (length > _IOC_SIZE(cmd))
 529                                length = _IOC_SIZE(cmd); /* truncate */
 530
 531                        if (copy_to_user((void __user *) arg,
 532                                        usblp->device_id_string,
 533                                        (unsigned long) length)) {
 534                                retval = -EFAULT;
 535                                goto done;
 536                        }
 537
 538                        break;
 539
 540                case IOCNR_GET_PROTOCOLS:
 541                        if (_IOC_DIR(cmd) != _IOC_READ ||
 542                            _IOC_SIZE(cmd) < sizeof(twoints)) {
 543                                retval = -EINVAL;
 544                                goto done;
 545                        }
 546
 547                        twoints[0] = usblp->current_protocol;
 548                        twoints[1] = 0;
 549                        for (i = USBLP_FIRST_PROTOCOL;
 550                             i <= USBLP_LAST_PROTOCOL; i++) {
 551                                if (usblp->protocol[i].alt_setting >= 0)
 552                                        twoints[1] |= (1<<i);
 553                        }
 554
 555                        if (copy_to_user((void __user *)arg,
 556                                        (unsigned char *)twoints,
 557                                        sizeof(twoints))) {
 558                                retval = -EFAULT;
 559                                goto done;
 560                        }
 561
 562                        break;
 563
 564                case IOCNR_SET_PROTOCOL:
 565                        if (_IOC_DIR(cmd) != _IOC_WRITE) {
 566                                retval = -EINVAL;
 567                                goto done;
 568                        }
 569
 570#ifdef DEBUG
 571                        if (arg == -10) {
 572                                usblp_dump(usblp);
 573                                break;
 574                        }
 575#endif
 576
 577                        usblp_unlink_urbs(usblp);
 578                        retval = usblp_set_protocol(usblp, arg);
 579                        if (retval < 0) {
 580                                usblp_set_protocol(usblp,
 581                                        usblp->current_protocol);
 582                        }
 583                        break;
 584
 585                case IOCNR_HP_SET_CHANNEL:
 586                        if (_IOC_DIR(cmd) != _IOC_WRITE ||
 587                            le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 588                            usblp->quirks & USBLP_QUIRK_BIDIR) {
 589                                retval = -EINVAL;
 590                                goto done;
 591                        }
 592
 593                        err = usblp_hp_channel_change_request(usblp,
 594                                arg, &newChannel);
 595                        if (err < 0) {
 596                                dev_err(&usblp->dev->dev,
 597                                        "usblp%d: error = %d setting "
 598                                        "HP channel\n",
 599                                        usblp->minor, err);
 600                                retval = -EIO;
 601                                goto done;
 602                        }
 603
 604                        dev_dbg(&usblp->intf->dev,
 605                                "usblp%d requested/got HP channel %ld/%d\n",
 606                                usblp->minor, arg, newChannel);
 607                        break;
 608
 609                case IOCNR_GET_BUS_ADDRESS:
 610                        if (_IOC_DIR(cmd) != _IOC_READ ||
 611                            _IOC_SIZE(cmd) < sizeof(twoints)) {
 612                                retval = -EINVAL;
 613                                goto done;
 614                        }
 615
 616                        twoints[0] = usblp->dev->bus->busnum;
 617                        twoints[1] = usblp->dev->devnum;
 618                        if (copy_to_user((void __user *)arg,
 619                                        (unsigned char *)twoints,
 620                                        sizeof(twoints))) {
 621                                retval = -EFAULT;
 622                                goto done;
 623                        }
 624
 625                        dev_dbg(&usblp->intf->dev,
 626                                "usblp%d is bus=%d, device=%d\n",
 627                                usblp->minor, twoints[0], twoints[1]);
 628                        break;
 629
 630                case IOCNR_GET_VID_PID:
 631                        if (_IOC_DIR(cmd) != _IOC_READ ||
 632                            _IOC_SIZE(cmd) < sizeof(twoints)) {
 633                                retval = -EINVAL;
 634                                goto done;
 635                        }
 636
 637                        twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 638                        twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 639                        if (copy_to_user((void __user *)arg,
 640                                        (unsigned char *)twoints,
 641                                        sizeof(twoints))) {
 642                                retval = -EFAULT;
 643                                goto done;
 644                        }
 645
 646                        dev_dbg(&usblp->intf->dev,
 647                                "usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
 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                        retval = usblp_read_status(usblp, usblp->statusbuf);
 666                        if (retval) {
 667                                printk_ratelimited(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                case LPABORT:
 679                        if (arg)
 680                                usblp->flags |= LP_ABORT;
 681                        else
 682                                usblp->flags &= ~LP_ABORT;
 683                        break;
 684
 685                default:
 686                        retval = -ENOTTY;
 687                }
 688
 689done:
 690        mutex_unlock(&usblp->mut);
 691        return retval;
 692}
 693
 694static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
 695{
 696        struct urb *urb;
 697        char *writebuf;
 698
 699        writebuf = kmalloc(transfer_length, GFP_KERNEL);
 700        if (writebuf == NULL)
 701                return NULL;
 702        urb = usb_alloc_urb(0, GFP_KERNEL);
 703        if (urb == NULL) {
 704                kfree(writebuf);
 705                return NULL;
 706        }
 707
 708        usb_fill_bulk_urb(urb, usblp->dev,
 709                usb_sndbulkpipe(usblp->dev,
 710                 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 711                writebuf, transfer_length, usblp_bulk_write, usblp);
 712        urb->transfer_flags |= URB_FREE_BUFFER;
 713
 714        return urb;
 715}
 716
 717static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 718{
 719        struct usblp *usblp = file->private_data;
 720        struct urb *writeurb;
 721        int rv;
 722        int transfer_length;
 723        ssize_t writecount = 0;
 724
 725        if (mutex_lock_interruptible(&usblp->wmut)) {
 726                rv = -EINTR;
 727                goto raise_biglock;
 728        }
 729        if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 730                goto raise_wait;
 731
 732        while (writecount < count) {
 733                /*
 734                 * Step 1: Submit next block.
 735                 */
 736                if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 737                        transfer_length = USBLP_BUF_SIZE;
 738
 739                rv = -ENOMEM;
 740                writeurb = usblp_new_writeurb(usblp, transfer_length);
 741                if (writeurb == NULL)
 742                        goto raise_urb;
 743                usb_anchor_urb(writeurb, &usblp->urbs);
 744
 745                if (copy_from_user(writeurb->transfer_buffer,
 746                                   buffer + writecount, transfer_length)) {
 747                        rv = -EFAULT;
 748                        goto raise_badaddr;
 749                }
 750
 751                spin_lock_irq(&usblp->lock);
 752                usblp->wcomplete = 0;
 753                spin_unlock_irq(&usblp->lock);
 754                if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 755                        usblp->wstatus = 0;
 756                        spin_lock_irq(&usblp->lock);
 757                        usblp->no_paper = 0;
 758                        usblp->wcomplete = 1;
 759                        wake_up(&usblp->wwait);
 760                        spin_unlock_irq(&usblp->lock);
 761                        if (rv != -ENOMEM)
 762                                rv = -EIO;
 763                        goto raise_submit;
 764                }
 765
 766                /*
 767                 * Step 2: Wait for transfer to end, collect results.
 768                 */
 769                rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 770                if (rv < 0) {
 771                        if (rv == -EAGAIN) {
 772                                /* Presume that it's going to complete well. */
 773                                writecount += transfer_length;
 774                        }
 775                        if (rv == -ENOSPC) {
 776                                spin_lock_irq(&usblp->lock);
 777                                usblp->no_paper = 1;    /* Mark for poll(2) */
 778                                spin_unlock_irq(&usblp->lock);
 779                                writecount += transfer_length;
 780                        }
 781                        /* Leave URB dangling, to be cleaned on close. */
 782                        goto collect_error;
 783                }
 784
 785                if (usblp->wstatus < 0) {
 786                        rv = -EIO;
 787                        goto collect_error;
 788                }
 789                /*
 790                 * This is critical: it must be our URB, not other writer's.
 791                 * The wmut exists mainly to cover us here.
 792                 */
 793                writecount += usblp->wstatus;
 794        }
 795
 796        mutex_unlock(&usblp->wmut);
 797        return writecount;
 798
 799raise_submit:
 800raise_badaddr:
 801        usb_unanchor_urb(writeurb);
 802        usb_free_urb(writeurb);
 803raise_urb:
 804raise_wait:
 805collect_error:          /* Out of raise sequence */
 806        mutex_unlock(&usblp->wmut);
 807raise_biglock:
 808        return writecount ? writecount : rv;
 809}
 810
 811/*
 812 * Notice that we fail to restart in a few cases: on EFAULT, on restart
 813 * error, etc. This is the historical behaviour. In all such cases we return
 814 * EIO, and applications loop in order to get the new read going.
 815 */
 816static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 817{
 818        struct usblp *usblp = file->private_data;
 819        ssize_t count;
 820        ssize_t avail;
 821        int rv;
 822
 823        if (!usblp->bidir)
 824                return -EINVAL;
 825
 826        rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 827        if (rv < 0)
 828                return rv;
 829
 830        if (!usblp->present) {
 831                count = -ENODEV;
 832                goto done;
 833        }
 834
 835        if ((avail = usblp->rstatus) < 0) {
 836                printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 837                    usblp->minor, (int)avail);
 838                usblp_submit_read(usblp);
 839                count = -EIO;
 840                goto done;
 841        }
 842
 843        count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 844        if (count != 0 &&
 845            copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 846                count = -EFAULT;
 847                goto done;
 848        }
 849
 850        if ((usblp->readcount += count) == avail) {
 851                if (usblp_submit_read(usblp) < 0) {
 852                        /* We don't want to leak USB return codes into errno. */
 853                        if (count == 0)
 854                                count = -EIO;
 855                        goto done;
 856                }
 857        }
 858
 859done:
 860        mutex_unlock(&usblp->mut);
 861        return count;
 862}
 863
 864/*
 865 * Wait for the write path to come idle.
 866 * This is called under the ->wmut, so the idle path stays idle.
 867 *
 868 * Our write path has a peculiar property: it does not buffer like a tty,
 869 * but waits for the write to succeed. This allows our ->release to bug out
 870 * without waiting for writes to drain. But it obviously does not work
 871 * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 872 * select(2) or poll(2) to wait for the buffer to drain before closing.
 873 * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 874 */
 875static int usblp_wwait(struct usblp *usblp, int nonblock)
 876{
 877        DECLARE_WAITQUEUE(waita, current);
 878        int rc;
 879        int err = 0;
 880
 881        add_wait_queue(&usblp->wwait, &waita);
 882        for (;;) {
 883                if (mutex_lock_interruptible(&usblp->mut)) {
 884                        rc = -EINTR;
 885                        break;
 886                }
 887                set_current_state(TASK_INTERRUPTIBLE);
 888                rc = usblp_wtest(usblp, nonblock);
 889                mutex_unlock(&usblp->mut);
 890                if (rc <= 0)
 891                        break;
 892
 893                if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
 894                        if (usblp->flags & LP_ABORT) {
 895                                err = usblp_check_status(usblp, err);
 896                                if (err == 1) { /* Paper out */
 897                                        rc = -ENOSPC;
 898                                        break;
 899                                }
 900                        } else {
 901                                /* Prod the printer, Gentoo#251237. */
 902                                mutex_lock(&usblp->mut);
 903                                usblp_read_status(usblp, usblp->statusbuf);
 904                                mutex_unlock(&usblp->mut);
 905                        }
 906                }
 907        }
 908        set_current_state(TASK_RUNNING);
 909        remove_wait_queue(&usblp->wwait, &waita);
 910        return rc;
 911}
 912
 913static int usblp_wtest(struct usblp *usblp, int nonblock)
 914{
 915        unsigned long flags;
 916
 917        if (!usblp->present)
 918                return -ENODEV;
 919        if (signal_pending(current))
 920                return -EINTR;
 921        spin_lock_irqsave(&usblp->lock, flags);
 922        if (usblp->wcomplete) {
 923                spin_unlock_irqrestore(&usblp->lock, flags);
 924                return 0;
 925        }
 926        spin_unlock_irqrestore(&usblp->lock, flags);
 927        if (nonblock)
 928                return -EAGAIN;
 929        return 1;
 930}
 931
 932/*
 933 * Wait for read bytes to become available. This probably should have been
 934 * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 935 * name for functions which lock and return.
 936 *
 937 * We do not use wait_event_interruptible because it makes locking iffy.
 938 */
 939static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 940{
 941        DECLARE_WAITQUEUE(waita, current);
 942        int rc;
 943
 944        add_wait_queue(&usblp->rwait, &waita);
 945        for (;;) {
 946                if (mutex_lock_interruptible(&usblp->mut)) {
 947                        rc = -EINTR;
 948                        break;
 949                }
 950                set_current_state(TASK_INTERRUPTIBLE);
 951                if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 952                        mutex_unlock(&usblp->mut);
 953                        break;
 954                }
 955                if (rc == 0)    /* Keep it locked */
 956                        break;
 957                mutex_unlock(&usblp->mut);
 958                schedule();
 959        }
 960        set_current_state(TASK_RUNNING);
 961        remove_wait_queue(&usblp->rwait, &waita);
 962        return rc;
 963}
 964
 965static int usblp_rtest(struct usblp *usblp, int nonblock)
 966{
 967        unsigned long flags;
 968
 969        if (!usblp->present)
 970                return -ENODEV;
 971        if (signal_pending(current))
 972                return -EINTR;
 973        spin_lock_irqsave(&usblp->lock, flags);
 974        if (usblp->rcomplete) {
 975                spin_unlock_irqrestore(&usblp->lock, flags);
 976                return 0;
 977        }
 978        spin_unlock_irqrestore(&usblp->lock, flags);
 979        if (nonblock)
 980                return -EAGAIN;
 981        return 1;
 982}
 983
 984/*
 985 * Please check ->bidir and other such things outside for now.
 986 */
 987static int usblp_submit_read(struct usblp *usblp)
 988{
 989        struct urb *urb;
 990        unsigned long flags;
 991        int rc;
 992
 993        rc = -ENOMEM;
 994        urb = usb_alloc_urb(0, GFP_KERNEL);
 995        if (urb == NULL)
 996                goto raise_urb;
 997
 998        usb_fill_bulk_urb(urb, usblp->dev,
 999                usb_rcvbulkpipe(usblp->dev,
1000                  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
1001                usblp->readbuf, USBLP_BUF_SIZE_IN,
1002                usblp_bulk_read, usblp);
1003        usb_anchor_urb(urb, &usblp->urbs);
1004
1005        spin_lock_irqsave(&usblp->lock, flags);
1006        usblp->readcount = 0; /* XXX Why here? */
1007        usblp->rcomplete = 0;
1008        spin_unlock_irqrestore(&usblp->lock, flags);
1009        if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1010                dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1011                spin_lock_irqsave(&usblp->lock, flags);
1012                usblp->rstatus = rc;
1013                usblp->rcomplete = 1;
1014                spin_unlock_irqrestore(&usblp->lock, flags);
1015                goto raise_submit;
1016        }
1017
1018        return 0;
1019
1020raise_submit:
1021        usb_unanchor_urb(urb);
1022        usb_free_urb(urb);
1023raise_urb:
1024        return rc;
1025}
1026
1027/*
1028 * Checks for printers that have quirks, such as requiring unidirectional
1029 * communication but reporting bidirectional; currently some HP printers
1030 * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1031 * sent at each open (like some Epsons).
1032 * Returns 1 if found, 0 if not found.
1033 *
1034 * HP recommended that we use the bidirectional interface but
1035 * don't attempt any bulk IN transfers from the IN endpoint.
1036 * Here's some more detail on the problem:
1037 * The problem is not that it isn't bidirectional though. The problem
1038 * is that if you request a device ID, or status information, while
1039 * the buffers are full, the return data will end up in the print data
1040 * buffer. For example if you make sure you never request the device ID
1041 * while you are sending print data, and you don't try to query the
1042 * printer status every couple of milliseconds, you will probably be OK.
1043 */
1044static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1045{
1046        int i;
1047
1048        for (i = 0; quirk_printers[i].vendorId; i++) {
1049                if (vendor == quirk_printers[i].vendorId &&
1050                    product == quirk_printers[i].productId)
1051                        return quirk_printers[i].quirks;
1052        }
1053        return 0;
1054}
1055
1056static const struct file_operations usblp_fops = {
1057        .owner =        THIS_MODULE,
1058        .read =         usblp_read,
1059        .write =        usblp_write,
1060        .poll =         usblp_poll,
1061        .unlocked_ioctl =       usblp_ioctl,
1062        .compat_ioctl =         usblp_ioctl,
1063        .open =         usblp_open,
1064        .release =      usblp_release,
1065        .llseek =       noop_llseek,
1066};
1067
1068static char *usblp_devnode(struct device *dev, umode_t *mode)
1069{
1070        return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1071}
1072
1073static struct usb_class_driver usblp_class = {
1074        .name =         "lp%d",
1075        .devnode =      usblp_devnode,
1076        .fops =         &usblp_fops,
1077        .minor_base =   USBLP_MINOR_BASE,
1078};
1079
1080static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1081{
1082        struct usb_interface *intf = to_usb_interface(dev);
1083        struct usblp *usblp = usb_get_intfdata(intf);
1084
1085        if (usblp->device_id_string[0] == 0 &&
1086            usblp->device_id_string[1] == 0)
1087                return 0;
1088
1089        return sprintf(buf, "%s", usblp->device_id_string+2);
1090}
1091
1092static DEVICE_ATTR_RO(ieee1284_id);
1093
1094static struct attribute *usblp_attrs[] = {
1095        &dev_attr_ieee1284_id.attr,
1096        NULL,
1097};
1098ATTRIBUTE_GROUPS(usblp);
1099
1100static int usblp_probe(struct usb_interface *intf,
1101                       const struct usb_device_id *id)
1102{
1103        struct usb_device *dev = interface_to_usbdev(intf);
1104        struct usblp *usblp;
1105        int protocol;
1106        int retval;
1107
1108        /* Malloc and start initializing usblp structure so we can use it
1109         * directly. */
1110        usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1111        if (!usblp) {
1112                retval = -ENOMEM;
1113                goto abort_ret;
1114        }
1115        usblp->dev = dev;
1116        mutex_init(&usblp->wmut);
1117        mutex_init(&usblp->mut);
1118        spin_lock_init(&usblp->lock);
1119        init_waitqueue_head(&usblp->rwait);
1120        init_waitqueue_head(&usblp->wwait);
1121        init_usb_anchor(&usblp->urbs);
1122        usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1123        usblp->intf = usb_get_intf(intf);
1124
1125        /* Malloc device ID string buffer to the largest expected length,
1126         * since we can re-query it on an ioctl and a dynamic string
1127         * could change in length. */
1128        if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1129                retval = -ENOMEM;
1130                goto abort;
1131        }
1132
1133        /*
1134         * Allocate read buffer. We somewhat wastefully
1135         * malloc both regardless of bidirectionality, because the
1136         * alternate setting can be changed later via an ioctl.
1137         */
1138        if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1139                retval = -ENOMEM;
1140                goto abort;
1141        }
1142
1143        /* Allocate buffer for printer status */
1144        usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1145        if (!usblp->statusbuf) {
1146                retval = -ENOMEM;
1147                goto abort;
1148        }
1149
1150        /* Lookup quirks for this printer. */
1151        usblp->quirks = usblp_quirks(
1152                le16_to_cpu(dev->descriptor.idVendor),
1153                le16_to_cpu(dev->descriptor.idProduct));
1154
1155        /* Analyze and pick initial alternate settings and endpoints. */
1156        protocol = usblp_select_alts(usblp);
1157        if (protocol < 0) {
1158                dev_dbg(&intf->dev,
1159                        "incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1160                        le16_to_cpu(dev->descriptor.idVendor),
1161                        le16_to_cpu(dev->descriptor.idProduct));
1162                retval = -ENODEV;
1163                goto abort;
1164        }
1165
1166        /* Setup the selected alternate setting and endpoints. */
1167        if (usblp_set_protocol(usblp, protocol) < 0) {
1168                retval = -ENODEV;       /* ->probe isn't ->ioctl */
1169                goto abort;
1170        }
1171
1172        /* Retrieve and store the device ID string. */
1173        usblp_cache_device_id_string(usblp);
1174
1175#ifdef DEBUG
1176        usblp_check_status(usblp, 0);
1177#endif
1178
1179        usb_set_intfdata(intf, usblp);
1180
1181        usblp->present = 1;
1182
1183        retval = usb_register_dev(intf, &usblp_class);
1184        if (retval) {
1185                dev_err(&intf->dev,
1186                        "usblp: Not able to get a minor (base %u, slice default): %d\n",
1187                        USBLP_MINOR_BASE, retval);
1188                goto abort_intfdata;
1189        }
1190        usblp->minor = intf->minor;
1191        dev_info(&intf->dev,
1192                "usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1193                usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1194                usblp->ifnum,
1195                usblp->protocol[usblp->current_protocol].alt_setting,
1196                usblp->current_protocol,
1197                le16_to_cpu(usblp->dev->descriptor.idVendor),
1198                le16_to_cpu(usblp->dev->descriptor.idProduct));
1199
1200        return 0;
1201
1202abort_intfdata:
1203        usb_set_intfdata(intf, NULL);
1204abort:
1205        kfree(usblp->readbuf);
1206        kfree(usblp->statusbuf);
1207        kfree(usblp->device_id_string);
1208        usb_put_intf(usblp->intf);
1209        kfree(usblp);
1210abort_ret:
1211        return retval;
1212}
1213
1214/*
1215 * We are a "new" style driver with usb_device_id table,
1216 * but our requirements are too intricate for simple match to handle.
1217 *
1218 * The "proto_bias" option may be used to specify the preferred protocol
1219 * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1220 * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1221 * then we bind to it.
1222 *
1223 * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1224 * is compatible with a stream of characters. If we find it, we bind to it.
1225 *
1226 * Note that the people from hpoj.sourceforge.net need to be able to
1227 * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1228 * for this purpose.
1229 *
1230 * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1231 * even though it's probably not stream-compatible, because this matches
1232 * the behaviour of the old code.
1233 *
1234 * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1235 * - the unidirectional interface.
1236 */
1237static int usblp_select_alts(struct usblp *usblp)
1238{
1239        struct usb_interface *if_alt;
1240        struct usb_host_interface *ifd;
1241        struct usb_endpoint_descriptor *epwrite, *epread;
1242        int p, i;
1243        int res;
1244
1245        if_alt = usblp->intf;
1246
1247        for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1248                usblp->protocol[p].alt_setting = -1;
1249
1250        /* Find out what we have. */
1251        for (i = 0; i < if_alt->num_altsetting; i++) {
1252                ifd = &if_alt->altsetting[i];
1253
1254                if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1255                    ifd->desc.bInterfaceSubClass != 1)
1256                        if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1257                                continue;
1258
1259                if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1260                    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1261                        continue;
1262
1263                /* Look for the expected bulk endpoints. */
1264                if (ifd->desc.bInterfaceProtocol > 1) {
1265                        res = usb_find_common_endpoints(ifd,
1266                                        &epread, &epwrite, NULL, NULL);
1267                } else {
1268                        epread = NULL;
1269                        res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1270                }
1271
1272                /* Ignore buggy hardware without the right endpoints. */
1273                if (res)
1274                        continue;
1275
1276                /* Turn off reads for buggy bidirectional printers. */
1277                if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1278                        printk(KERN_INFO "usblp%d: Disabling reads from "
1279                            "problematic bidirectional printer\n",
1280                            usblp->minor);
1281                        epread = NULL;
1282                }
1283
1284                usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1285                                ifd->desc.bAlternateSetting;
1286                usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1287                usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1288        }
1289
1290        /* If our requested protocol is supported, then use it. */
1291        if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1292            proto_bias <= USBLP_LAST_PROTOCOL &&
1293            usblp->protocol[proto_bias].alt_setting != -1)
1294                return proto_bias;
1295
1296        /* Ordering is important here. */
1297        if (usblp->protocol[2].alt_setting != -1)
1298                return 2;
1299        if (usblp->protocol[1].alt_setting != -1)
1300                return 1;
1301        if (usblp->protocol[3].alt_setting != -1)
1302                return 3;
1303
1304        /* If nothing is available, then don't bind to this device. */
1305        return -1;
1306}
1307
1308static int usblp_set_protocol(struct usblp *usblp, int protocol)
1309{
1310        int r, alts;
1311
1312        if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1313                return -EINVAL;
1314
1315        alts = usblp->protocol[protocol].alt_setting;
1316        if (alts < 0)
1317                return -EINVAL;
1318        r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1319        if (r < 0) {
1320                printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1321                        alts, usblp->ifnum);
1322                return r;
1323        }
1324
1325        usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1326        usblp->current_protocol = protocol;
1327        dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1328                usblp->minor, protocol);
1329        return 0;
1330}
1331
1332/* Retrieves and caches device ID string.
1333 * Returns length, including length bytes but not null terminator.
1334 * On error, returns a negative errno value. */
1335static int usblp_cache_device_id_string(struct usblp *usblp)
1336{
1337        int err, length;
1338
1339        err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1340        if (err < 0) {
1341                dev_dbg(&usblp->intf->dev,
1342                        "usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1343                        usblp->minor, err);
1344                usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1345                return -EIO;
1346        }
1347
1348        /* First two bytes are length in big-endian.
1349         * They count themselves, and we copy them into
1350         * the user's buffer. */
1351        length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1352        if (length < 2)
1353                length = 2;
1354        else if (length >= USBLP_DEVICE_ID_SIZE)
1355                length = USBLP_DEVICE_ID_SIZE - 1;
1356        usblp->device_id_string[length] = '\0';
1357
1358        dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1359                usblp->minor, length, &usblp->device_id_string[2]);
1360
1361        return length;
1362}
1363
1364static void usblp_disconnect(struct usb_interface *intf)
1365{
1366        struct usblp *usblp = usb_get_intfdata(intf);
1367
1368        usb_deregister_dev(intf, &usblp_class);
1369
1370        if (!usblp || !usblp->dev) {
1371                dev_err(&intf->dev, "bogus disconnect\n");
1372                BUG();
1373        }
1374
1375        mutex_lock(&usblp_mutex);
1376        mutex_lock(&usblp->mut);
1377        usblp->present = 0;
1378        wake_up(&usblp->wwait);
1379        wake_up(&usblp->rwait);
1380        usb_set_intfdata(intf, NULL);
1381
1382        usblp_unlink_urbs(usblp);
1383        mutex_unlock(&usblp->mut);
1384        usb_poison_anchored_urbs(&usblp->urbs);
1385
1386        if (!usblp->used)
1387                usblp_cleanup(usblp);
1388
1389        mutex_unlock(&usblp_mutex);
1390}
1391
1392static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1393{
1394        struct usblp *usblp = usb_get_intfdata(intf);
1395
1396        usblp_unlink_urbs(usblp);
1397#if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1398        /* not strictly necessary, but just in case */
1399        wake_up(&usblp->wwait);
1400        wake_up(&usblp->rwait);
1401#endif
1402
1403        return 0;
1404}
1405
1406static int usblp_resume(struct usb_interface *intf)
1407{
1408        struct usblp *usblp = usb_get_intfdata(intf);
1409        int r;
1410
1411        r = handle_bidir(usblp);
1412
1413        return r;
1414}
1415
1416static const struct usb_device_id usblp_ids[] = {
1417        { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1418        { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1419        { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1420        { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1421        { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1422        { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1423        { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1424        { }                                             /* Terminating entry */
1425};
1426
1427MODULE_DEVICE_TABLE(usb, usblp_ids);
1428
1429static struct usb_driver usblp_driver = {
1430        .name =         "usblp",
1431        .probe =        usblp_probe,
1432        .disconnect =   usblp_disconnect,
1433        .suspend =      usblp_suspend,
1434        .resume =       usblp_resume,
1435        .id_table =     usblp_ids,
1436        .dev_groups =   usblp_groups,
1437        .supports_autosuspend = 1,
1438};
1439
1440module_usb_driver(usblp_driver);
1441
1442MODULE_AUTHOR(DRIVER_AUTHOR);
1443MODULE_DESCRIPTION(DRIVER_DESC);
1444module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1445MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1446MODULE_LICENSE("GPL");
1447