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");