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);
 472	mutex_unlock(&usblp_mutex);
 473	return 0;
 474}
 475
 476/* No kernel lock - fine */
 477static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
 478{
 479	__poll_t ret;
 480	unsigned long flags;
 481
 482	struct usblp *usblp = file->private_data;
 483	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
 484	poll_wait(file, &usblp->rwait, wait);
 485	poll_wait(file, &usblp->wwait, wait);
 486	spin_lock_irqsave(&usblp->lock, flags);
 487	ret = ((usblp->bidir && usblp->rcomplete) ? EPOLLIN  | EPOLLRDNORM : 0) |
 488	   ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 0);
 489	spin_unlock_irqrestore(&usblp->lock, flags);
 490	return ret;
 491}
 492
 493static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 494{
 495	struct usblp *usblp = file->private_data;
 496	int length, err, i;
 497	unsigned char newChannel;
 498	int status;
 499	int twoints[2];
 500	int retval = 0;
 501
 502	mutex_lock(&usblp->mut);
 503	if (!usblp->present) {
 504		retval = -ENODEV;
 505		goto done;
 506	}
 507
 508	dev_dbg(&usblp->intf->dev,
 509		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
 510		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
 511
 512	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
 513
 514		switch (_IOC_NR(cmd)) {
 515
 516		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
 517			if (_IOC_DIR(cmd) != _IOC_READ) {
 518				retval = -EINVAL;
 519				goto done;
 520			}
 521
 522			length = usblp_cache_device_id_string(usblp);
 523			if (length < 0) {
 524				retval = length;
 525				goto done;
 526			}
 527			if (length > _IOC_SIZE(cmd))
 528				length = _IOC_SIZE(cmd); /* truncate */
 529
 530			if (copy_to_user((void __user *) arg,
 531					usblp->device_id_string,
 532					(unsigned long) length)) {
 533				retval = -EFAULT;
 534				goto done;
 535			}
 536
 537			break;
 538
 539		case IOCNR_GET_PROTOCOLS:
 540			if (_IOC_DIR(cmd) != _IOC_READ ||
 541			    _IOC_SIZE(cmd) < sizeof(twoints)) {
 542				retval = -EINVAL;
 543				goto done;
 544			}
 545
 546			twoints[0] = usblp->current_protocol;
 547			twoints[1] = 0;
 548			for (i = USBLP_FIRST_PROTOCOL;
 549			     i <= USBLP_LAST_PROTOCOL; i++) {
 550				if (usblp->protocol[i].alt_setting >= 0)
 551					twoints[1] |= (1<<i);
 552			}
 553
 554			if (copy_to_user((void __user *)arg,
 555					(unsigned char *)twoints,
 556					sizeof(twoints))) {
 557				retval = -EFAULT;
 558				goto done;
 559			}
 560
 561			break;
 562
 563		case IOCNR_SET_PROTOCOL:
 564			if (_IOC_DIR(cmd) != _IOC_WRITE) {
 565				retval = -EINVAL;
 566				goto done;
 567			}
 568
 569#ifdef DEBUG
 570			if (arg == -10) {
 571				usblp_dump(usblp);
 572				break;
 573			}
 574#endif
 575
 576			usblp_unlink_urbs(usblp);
 577			retval = usblp_set_protocol(usblp, arg);
 578			if (retval < 0) {
 579				usblp_set_protocol(usblp,
 580					usblp->current_protocol);
 581			}
 582			break;
 583
 584		case IOCNR_HP_SET_CHANNEL:
 585			if (_IOC_DIR(cmd) != _IOC_WRITE ||
 586			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
 587			    usblp->quirks & USBLP_QUIRK_BIDIR) {
 588				retval = -EINVAL;
 589				goto done;
 590			}
 591
 592			err = usblp_hp_channel_change_request(usblp,
 593				arg, &newChannel);
 594			if (err < 0) {
 595				dev_err(&usblp->dev->dev,
 596					"usblp%d: error = %d setting "
 597					"HP channel\n",
 598					usblp->minor, err);
 599				retval = -EIO;
 600				goto done;
 601			}
 602
 603			dev_dbg(&usblp->intf->dev,
 604				"usblp%d requested/got HP channel %ld/%d\n",
 605				usblp->minor, arg, newChannel);
 606			break;
 607
 608		case IOCNR_GET_BUS_ADDRESS:
 609			if (_IOC_DIR(cmd) != _IOC_READ ||
 610			    _IOC_SIZE(cmd) < sizeof(twoints)) {
 611				retval = -EINVAL;
 612				goto done;
 613			}
 614
 615			twoints[0] = usblp->dev->bus->busnum;
 616			twoints[1] = usblp->dev->devnum;
 617			if (copy_to_user((void __user *)arg,
 618					(unsigned char *)twoints,
 619					sizeof(twoints))) {
 620				retval = -EFAULT;
 621				goto done;
 622			}
 623
 624			dev_dbg(&usblp->intf->dev,
 625				"usblp%d is bus=%d, device=%d\n",
 626				usblp->minor, twoints[0], twoints[1]);
 627			break;
 628
 629		case IOCNR_GET_VID_PID:
 630			if (_IOC_DIR(cmd) != _IOC_READ ||
 631			    _IOC_SIZE(cmd) < sizeof(twoints)) {
 632				retval = -EINVAL;
 633				goto done;
 634			}
 635
 636			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
 637			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
 638			if (copy_to_user((void __user *)arg,
 639					(unsigned char *)twoints,
 640					sizeof(twoints))) {
 641				retval = -EFAULT;
 642				goto done;
 643			}
 644
 645			dev_dbg(&usblp->intf->dev,
 646				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
 647				usblp->minor, twoints[0], twoints[1]);
 648			break;
 649
 650		case IOCNR_SOFT_RESET:
 651			if (_IOC_DIR(cmd) != _IOC_NONE) {
 652				retval = -EINVAL;
 653				goto done;
 654			}
 655			retval = usblp_reset(usblp);
 656			break;
 657		default:
 658			retval = -ENOTTY;
 659		}
 660	else	/* old-style ioctl value */
 661		switch (cmd) {
 662
 663		case LPGETSTATUS:
 664			retval = usblp_read_status(usblp, usblp->statusbuf);
 665			if (retval) {
 666				printk_ratelimited(KERN_ERR "usblp%d:"
 667					    "failed reading printer status (%d)\n",
 668					    usblp->minor, retval);
 669				retval = -EIO;
 670				goto done;
 671			}
 672			status = *usblp->statusbuf;
 673			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
 674				retval = -EFAULT;
 675			break;
 676
 677		case LPABORT:
 678			if (arg)
 679				usblp->flags |= LP_ABORT;
 680			else
 681				usblp->flags &= ~LP_ABORT;
 682			break;
 683
 684		default:
 685			retval = -ENOTTY;
 686		}
 687
 688done:
 689	mutex_unlock(&usblp->mut);
 690	return retval;
 691}
 692
 693static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
 694{
 695	struct urb *urb;
 696	char *writebuf;
 697
 698	writebuf = kmalloc(transfer_length, GFP_KERNEL);
 699	if (writebuf == NULL)
 700		return NULL;
 701	urb = usb_alloc_urb(0, GFP_KERNEL);
 702	if (urb == NULL) {
 703		kfree(writebuf);
 704		return NULL;
 705	}
 706
 707	usb_fill_bulk_urb(urb, usblp->dev,
 708		usb_sndbulkpipe(usblp->dev,
 709		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
 710		writebuf, transfer_length, usblp_bulk_write, usblp);
 711	urb->transfer_flags |= URB_FREE_BUFFER;
 712
 713	return urb;
 714}
 715
 716static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 717{
 718	struct usblp *usblp = file->private_data;
 719	struct urb *writeurb;
 720	int rv;
 721	int transfer_length;
 722	ssize_t writecount = 0;
 723
 724	if (mutex_lock_interruptible(&usblp->wmut)) {
 725		rv = -EINTR;
 726		goto raise_biglock;
 727	}
 728	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
 729		goto raise_wait;
 730
 731	while (writecount < count) {
 732		/*
 733		 * Step 1: Submit next block.
 734		 */
 735		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
 736			transfer_length = USBLP_BUF_SIZE;
 737
 738		rv = -ENOMEM;
 739		writeurb = usblp_new_writeurb(usblp, transfer_length);
 740		if (writeurb == NULL)
 741			goto raise_urb;
 742		usb_anchor_urb(writeurb, &usblp->urbs);
 743
 744		if (copy_from_user(writeurb->transfer_buffer,
 745				   buffer + writecount, transfer_length)) {
 746			rv = -EFAULT;
 747			goto raise_badaddr;
 748		}
 749
 750		spin_lock_irq(&usblp->lock);
 751		usblp->wcomplete = 0;
 752		spin_unlock_irq(&usblp->lock);
 753		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
 754			usblp->wstatus = 0;
 755			spin_lock_irq(&usblp->lock);
 756			usblp->no_paper = 0;
 757			usblp->wcomplete = 1;
 758			wake_up(&usblp->wwait);
 759			spin_unlock_irq(&usblp->lock);
 760			if (rv != -ENOMEM)
 761				rv = -EIO;
 762			goto raise_submit;
 763		}
 764
 765		/*
 766		 * Step 2: Wait for transfer to end, collect results.
 767		 */
 768		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
 769		if (rv < 0) {
 770			if (rv == -EAGAIN) {
 771				/* Presume that it's going to complete well. */
 772				writecount += transfer_length;
 773			}
 774			if (rv == -ENOSPC) {
 775				spin_lock_irq(&usblp->lock);
 776				usblp->no_paper = 1;	/* Mark for poll(2) */
 777				spin_unlock_irq(&usblp->lock);
 778				writecount += transfer_length;
 779			}
 780			/* Leave URB dangling, to be cleaned on close. */
 781			goto collect_error;
 782		}
 783
 784		if (usblp->wstatus < 0) {
 785			rv = -EIO;
 786			goto collect_error;
 787		}
 788		/*
 789		 * This is critical: it must be our URB, not other writer's.
 790		 * The wmut exists mainly to cover us here.
 791		 */
 792		writecount += usblp->wstatus;
 793	}
 794
 795	mutex_unlock(&usblp->wmut);
 796	return writecount;
 797
 798raise_submit:
 799raise_badaddr:
 800	usb_unanchor_urb(writeurb);
 801	usb_free_urb(writeurb);
 802raise_urb:
 803raise_wait:
 804collect_error:		/* Out of raise sequence */
 805	mutex_unlock(&usblp->wmut);
 806raise_biglock:
 807	return writecount ? writecount : rv;
 808}
 809
 810/*
 811 * Notice that we fail to restart in a few cases: on EFAULT, on restart
 812 * error, etc. This is the historical behaviour. In all such cases we return
 813 * EIO, and applications loop in order to get the new read going.
 814 */
 815static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
 816{
 817	struct usblp *usblp = file->private_data;
 818	ssize_t count;
 819	ssize_t avail;
 820	int rv;
 821
 822	if (!usblp->bidir)
 823		return -EINVAL;
 824
 825	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
 826	if (rv < 0)
 827		return rv;
 828
 829	if ((avail = usblp->rstatus) < 0) {
 830		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 831		    usblp->minor, (int)avail);
 832		usblp_submit_read(usblp);
 833		count = -EIO;
 834		goto done;
 835	}
 836
 837	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
 838	if (count != 0 &&
 839	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
 840		count = -EFAULT;
 841		goto done;
 842	}
 843
 844	if ((usblp->readcount += count) == avail) {
 845		if (usblp_submit_read(usblp) < 0) {
 846			/* We don't want to leak USB return codes into errno. */
 847			if (count == 0)
 848				count = -EIO;
 849			goto done;
 850		}
 851	}
 852
 853done:
 854	mutex_unlock(&usblp->mut);
 855	return count;
 856}
 857
 858/*
 859 * Wait for the write path to come idle.
 860 * This is called under the ->wmut, so the idle path stays idle.
 861 *
 862 * Our write path has a peculiar property: it does not buffer like a tty,
 863 * but waits for the write to succeed. This allows our ->release to bug out
 864 * without waiting for writes to drain. But it obviously does not work
 865 * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 866 * select(2) or poll(2) to wait for the buffer to drain before closing.
 867 * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 868 */
 869static int usblp_wwait(struct usblp *usblp, int nonblock)
 870{
 871	DECLARE_WAITQUEUE(waita, current);
 872	int rc;
 873	int err = 0;
 874
 875	add_wait_queue(&usblp->wwait, &waita);
 876	for (;;) {
 877		if (mutex_lock_interruptible(&usblp->mut)) {
 878			rc = -EINTR;
 879			break;
 880		}
 881		set_current_state(TASK_INTERRUPTIBLE);
 882		rc = usblp_wtest(usblp, nonblock);
 883		mutex_unlock(&usblp->mut);
 884		if (rc <= 0)
 885			break;
 886
 887		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
 888			if (usblp->flags & LP_ABORT) {
 889				err = usblp_check_status(usblp, err);
 890				if (err == 1) {	/* Paper out */
 891					rc = -ENOSPC;
 892					break;
 893				}
 894			} else {
 895				/* Prod the printer, Gentoo#251237. */
 896				mutex_lock(&usblp->mut);
 897				usblp_read_status(usblp, usblp->statusbuf);
 898				mutex_unlock(&usblp->mut);
 899			}
 900		}
 901	}
 902	set_current_state(TASK_RUNNING);
 903	remove_wait_queue(&usblp->wwait, &waita);
 904	return rc;
 905}
 906
 907static int usblp_wtest(struct usblp *usblp, int nonblock)
 908{
 909	unsigned long flags;
 910
 911	if (!usblp->present)
 912		return -ENODEV;
 913	if (signal_pending(current))
 914		return -EINTR;
 915	spin_lock_irqsave(&usblp->lock, flags);
 916	if (usblp->wcomplete) {
 917		spin_unlock_irqrestore(&usblp->lock, flags);
 918		return 0;
 919	}
 920	spin_unlock_irqrestore(&usblp->lock, flags);
 921	if (nonblock)
 922		return -EAGAIN;
 923	return 1;
 924}
 925
 926/*
 927 * Wait for read bytes to become available. This probably should have been
 928 * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 929 * name for functions which lock and return.
 930 *
 931 * We do not use wait_event_interruptible because it makes locking iffy.
 932 */
 933static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
 934{
 935	DECLARE_WAITQUEUE(waita, current);
 936	int rc;
 937
 938	add_wait_queue(&usblp->rwait, &waita);
 939	for (;;) {
 940		if (mutex_lock_interruptible(&usblp->mut)) {
 941			rc = -EINTR;
 942			break;
 943		}
 944		set_current_state(TASK_INTERRUPTIBLE);
 945		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
 946			mutex_unlock(&usblp->mut);
 947			break;
 948		}
 949		if (rc == 0)	/* Keep it locked */
 950			break;
 951		mutex_unlock(&usblp->mut);
 952		schedule();
 953	}
 954	set_current_state(TASK_RUNNING);
 955	remove_wait_queue(&usblp->rwait, &waita);
 956	return rc;
 957}
 958
 959static int usblp_rtest(struct usblp *usblp, int nonblock)
 960{
 961	unsigned long flags;
 962
 963	if (!usblp->present)
 964		return -ENODEV;
 965	if (signal_pending(current))
 966		return -EINTR;
 967	spin_lock_irqsave(&usblp->lock, flags);
 968	if (usblp->rcomplete) {
 969		spin_unlock_irqrestore(&usblp->lock, flags);
 970		return 0;
 971	}
 972	spin_unlock_irqrestore(&usblp->lock, flags);
 973	if (nonblock)
 974		return -EAGAIN;
 975	return 1;
 976}
 977
 978/*
 979 * Please check ->bidir and other such things outside for now.
 980 */
 981static int usblp_submit_read(struct usblp *usblp)
 982{
 983	struct urb *urb;
 984	unsigned long flags;
 985	int rc;
 986
 987	rc = -ENOMEM;
 988	urb = usb_alloc_urb(0, GFP_KERNEL);
 989	if (urb == NULL)
 990		goto raise_urb;
 991
 992	usb_fill_bulk_urb(urb, usblp->dev,
 993		usb_rcvbulkpipe(usblp->dev,
 994		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
 995		usblp->readbuf, USBLP_BUF_SIZE_IN,
 996		usblp_bulk_read, usblp);
 997	usb_anchor_urb(urb, &usblp->urbs);
 998
 999	spin_lock_irqsave(&usblp->lock, flags);
1000	usblp->readcount = 0; /* XXX Why here? */
1001	usblp->rcomplete = 0;
1002	spin_unlock_irqrestore(&usblp->lock, flags);
1003	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1004		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1005		spin_lock_irqsave(&usblp->lock, flags);
1006		usblp->rstatus = rc;
1007		usblp->rcomplete = 1;
1008		spin_unlock_irqrestore(&usblp->lock, flags);
1009		goto raise_submit;
1010	}
1011
1012	return 0;
1013
1014raise_submit:
1015	usb_unanchor_urb(urb);
1016	usb_free_urb(urb);
1017raise_urb:
1018	return rc;
1019}
1020
1021/*
1022 * Checks for printers that have quirks, such as requiring unidirectional
1023 * communication but reporting bidirectional; currently some HP printers
1024 * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1025 * sent at each open (like some Epsons).
1026 * Returns 1 if found, 0 if not found.
1027 *
1028 * HP recommended that we use the bidirectional interface but
1029 * don't attempt any bulk IN transfers from the IN endpoint.
1030 * Here's some more detail on the problem:
1031 * The problem is not that it isn't bidirectional though. The problem
1032 * is that if you request a device ID, or status information, while
1033 * the buffers are full, the return data will end up in the print data
1034 * buffer. For example if you make sure you never request the device ID
1035 * while you are sending print data, and you don't try to query the
1036 * printer status every couple of milliseconds, you will probably be OK.
1037 */
1038static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1039{
1040	int i;
1041
1042	for (i = 0; quirk_printers[i].vendorId; i++) {
1043		if (vendor == quirk_printers[i].vendorId &&
1044		    product == quirk_printers[i].productId)
1045			return quirk_printers[i].quirks;
1046	}
1047	return 0;
1048}
1049
1050static const struct file_operations usblp_fops = {
1051	.owner =	THIS_MODULE,
1052	.read =		usblp_read,
1053	.write =	usblp_write,
1054	.poll =		usblp_poll,
1055	.unlocked_ioctl =	usblp_ioctl,
1056	.compat_ioctl =		usblp_ioctl,
1057	.open =		usblp_open,
1058	.release =	usblp_release,
1059	.llseek =	noop_llseek,
1060};
1061
1062static char *usblp_devnode(struct device *dev, umode_t *mode)
1063{
1064	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1065}
1066
1067static struct usb_class_driver usblp_class = {
1068	.name =		"lp%d",
1069	.devnode =	usblp_devnode,
1070	.fops =		&usblp_fops,
1071	.minor_base =	USBLP_MINOR_BASE,
1072};
1073
1074static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1075{
1076	struct usb_interface *intf = to_usb_interface(dev);
1077	struct usblp *usblp = usb_get_intfdata(intf);
1078
1079	if (usblp->device_id_string[0] == 0 &&
1080	    usblp->device_id_string[1] == 0)
1081		return 0;
1082
1083	return sprintf(buf, "%s", usblp->device_id_string+2);
1084}
1085
1086static DEVICE_ATTR_RO(ieee1284_id);
1087
1088static struct attribute *usblp_attrs[] = {
1089	&dev_attr_ieee1284_id.attr,
1090	NULL,
1091};
1092ATTRIBUTE_GROUPS(usblp);
1093
1094static int usblp_probe(struct usb_interface *intf,
1095		       const struct usb_device_id *id)
1096{
1097	struct usb_device *dev = interface_to_usbdev(intf);
1098	struct usblp *usblp;
1099	int protocol;
1100	int retval;
1101
1102	/* Malloc and start initializing usblp structure so we can use it
1103	 * directly. */
1104	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1105	if (!usblp) {
1106		retval = -ENOMEM;
1107		goto abort_ret;
1108	}
1109	usblp->dev = dev;
1110	mutex_init(&usblp->wmut);
1111	mutex_init(&usblp->mut);
1112	spin_lock_init(&usblp->lock);
1113	init_waitqueue_head(&usblp->rwait);
1114	init_waitqueue_head(&usblp->wwait);
1115	init_usb_anchor(&usblp->urbs);
1116	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1117	usblp->intf = usb_get_intf(intf);
1118
1119	/* Malloc device ID string buffer to the largest expected length,
1120	 * since we can re-query it on an ioctl and a dynamic string
1121	 * could change in length. */
1122	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1123		retval = -ENOMEM;
1124		goto abort;
1125	}
1126
1127	/*
1128	 * Allocate read buffer. We somewhat wastefully
1129	 * malloc both regardless of bidirectionality, because the
1130	 * alternate setting can be changed later via an ioctl.
1131	 */
1132	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1133		retval = -ENOMEM;
1134		goto abort;
1135	}
1136
1137	/* Allocate buffer for printer status */
1138	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1139	if (!usblp->statusbuf) {
1140		retval = -ENOMEM;
1141		goto abort;
1142	}
1143
1144	/* Lookup quirks for this printer. */
1145	usblp->quirks = usblp_quirks(
1146		le16_to_cpu(dev->descriptor.idVendor),
1147		le16_to_cpu(dev->descriptor.idProduct));
1148
1149	/* Analyze and pick initial alternate settings and endpoints. */
1150	protocol = usblp_select_alts(usblp);
1151	if (protocol < 0) {
1152		dev_dbg(&intf->dev,
1153			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1154			le16_to_cpu(dev->descriptor.idVendor),
1155			le16_to_cpu(dev->descriptor.idProduct));
1156		retval = -ENODEV;
1157		goto abort;
1158	}
1159
1160	/* Setup the selected alternate setting and endpoints. */
1161	if (usblp_set_protocol(usblp, protocol) < 0) {
1162		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1163		goto abort;
1164	}
1165
1166	/* Retrieve and store the device ID string. */
1167	usblp_cache_device_id_string(usblp);
 
 
 
1168
1169#ifdef DEBUG
1170	usblp_check_status(usblp, 0);
1171#endif
1172
1173	usb_set_intfdata(intf, usblp);
1174
1175	usblp->present = 1;
1176
1177	retval = usb_register_dev(intf, &usblp_class);
1178	if (retval) {
1179		dev_err(&intf->dev,
1180			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1181			USBLP_MINOR_BASE, retval);
1182		goto abort_intfdata;
1183	}
1184	usblp->minor = intf->minor;
1185	dev_info(&intf->dev,
1186		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1187		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1188		usblp->ifnum,
1189		usblp->protocol[usblp->current_protocol].alt_setting,
1190		usblp->current_protocol,
1191		le16_to_cpu(usblp->dev->descriptor.idVendor),
1192		le16_to_cpu(usblp->dev->descriptor.idProduct));
1193
1194	return 0;
1195
1196abort_intfdata:
1197	usb_set_intfdata(intf, NULL);
 
1198abort:
1199	kfree(usblp->readbuf);
1200	kfree(usblp->statusbuf);
1201	kfree(usblp->device_id_string);
1202	usb_put_intf(usblp->intf);
1203	kfree(usblp);
1204abort_ret:
1205	return retval;
1206}
1207
1208/*
1209 * We are a "new" style driver with usb_device_id table,
1210 * but our requirements are too intricate for simple match to handle.
1211 *
1212 * The "proto_bias" option may be used to specify the preferred protocol
1213 * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1214 * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1215 * then we bind to it.
1216 *
1217 * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1218 * is compatible with a stream of characters. If we find it, we bind to it.
1219 *
1220 * Note that the people from hpoj.sourceforge.net need to be able to
1221 * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1222 * for this purpose.
1223 *
1224 * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1225 * even though it's probably not stream-compatible, because this matches
1226 * the behaviour of the old code.
1227 *
1228 * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1229 * - the unidirectional interface.
1230 */
1231static int usblp_select_alts(struct usblp *usblp)
1232{
1233	struct usb_interface *if_alt;
1234	struct usb_host_interface *ifd;
1235	struct usb_endpoint_descriptor *epwrite, *epread;
1236	int p, i;
1237	int res;
1238
1239	if_alt = usblp->intf;
1240
1241	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1242		usblp->protocol[p].alt_setting = -1;
1243
1244	/* Find out what we have. */
1245	for (i = 0; i < if_alt->num_altsetting; i++) {
1246		ifd = &if_alt->altsetting[i];
1247
1248		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1249		    ifd->desc.bInterfaceSubClass != 1)
1250			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1251				continue;
1252
1253		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1254		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1255			continue;
1256
1257		/* Look for the expected bulk endpoints. */
1258		if (ifd->desc.bInterfaceProtocol > 1) {
1259			res = usb_find_common_endpoints(ifd,
1260					&epread, &epwrite, NULL, NULL);
1261		} else {
1262			epread = NULL;
1263			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1264		}
1265
1266		/* Ignore buggy hardware without the right endpoints. */
1267		if (res)
1268			continue;
1269
1270		/* Turn off reads for buggy bidirectional printers. */
1271		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1272			printk(KERN_INFO "usblp%d: Disabling reads from "
1273			    "problematic bidirectional printer\n",
1274			    usblp->minor);
1275			epread = NULL;
1276		}
1277
1278		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1279				ifd->desc.bAlternateSetting;
1280		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1281		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1282	}
1283
1284	/* If our requested protocol is supported, then use it. */
1285	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1286	    proto_bias <= USBLP_LAST_PROTOCOL &&
1287	    usblp->protocol[proto_bias].alt_setting != -1)
1288		return proto_bias;
1289
1290	/* Ordering is important here. */
1291	if (usblp->protocol[2].alt_setting != -1)
1292		return 2;
1293	if (usblp->protocol[1].alt_setting != -1)
1294		return 1;
1295	if (usblp->protocol[3].alt_setting != -1)
1296		return 3;
1297
1298	/* If nothing is available, then don't bind to this device. */
1299	return -1;
1300}
1301
1302static int usblp_set_protocol(struct usblp *usblp, int protocol)
1303{
1304	int r, alts;
1305
1306	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1307		return -EINVAL;
1308
1309	alts = usblp->protocol[protocol].alt_setting;
1310	if (alts < 0)
1311		return -EINVAL;
1312	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1313	if (r < 0) {
1314		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1315			alts, usblp->ifnum);
1316		return r;
1317	}
1318
1319	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1320	usblp->current_protocol = protocol;
1321	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1322		usblp->minor, protocol);
1323	return 0;
1324}
1325
1326/* Retrieves and caches device ID string.
1327 * Returns length, including length bytes but not null terminator.
1328 * On error, returns a negative errno value. */
1329static int usblp_cache_device_id_string(struct usblp *usblp)
1330{
1331	int err, length;
1332
1333	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1334	if (err < 0) {
1335		dev_dbg(&usblp->intf->dev,
1336			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1337			usblp->minor, err);
1338		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1339		return -EIO;
1340	}
1341
1342	/* First two bytes are length in big-endian.
1343	 * They count themselves, and we copy them into
1344	 * the user's buffer. */
1345	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1346	if (length < 2)
1347		length = 2;
1348	else if (length >= USBLP_DEVICE_ID_SIZE)
1349		length = USBLP_DEVICE_ID_SIZE - 1;
1350	usblp->device_id_string[length] = '\0';
1351
1352	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1353		usblp->minor, length, &usblp->device_id_string[2]);
1354
1355	return length;
1356}
1357
1358static void usblp_disconnect(struct usb_interface *intf)
1359{
1360	struct usblp *usblp = usb_get_intfdata(intf);
1361
1362	usb_deregister_dev(intf, &usblp_class);
1363
1364	if (!usblp || !usblp->dev) {
1365		dev_err(&intf->dev, "bogus disconnect\n");
1366		BUG();
1367	}
1368
 
 
1369	mutex_lock(&usblp_mutex);
1370	mutex_lock(&usblp->mut);
1371	usblp->present = 0;
1372	wake_up(&usblp->wwait);
1373	wake_up(&usblp->rwait);
1374	usb_set_intfdata(intf, NULL);
1375
1376	usblp_unlink_urbs(usblp);
1377	mutex_unlock(&usblp->mut);
1378
1379	if (!usblp->used)
1380		usblp_cleanup(usblp);
1381	mutex_unlock(&usblp_mutex);
1382}
1383
1384static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1385{
1386	struct usblp *usblp = usb_get_intfdata(intf);
1387
1388	usblp_unlink_urbs(usblp);
1389#if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1390	/* not strictly necessary, but just in case */
1391	wake_up(&usblp->wwait);
1392	wake_up(&usblp->rwait);
1393#endif
1394
1395	return 0;
1396}
1397
1398static int usblp_resume(struct usb_interface *intf)
1399{
1400	struct usblp *usblp = usb_get_intfdata(intf);
1401	int r;
1402
1403	r = handle_bidir(usblp);
1404
1405	return r;
1406}
1407
1408static const struct usb_device_id usblp_ids[] = {
1409	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1410	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1411	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1412	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1413	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1414	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1415	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1416	{ }						/* Terminating entry */
1417};
1418
1419MODULE_DEVICE_TABLE(usb, usblp_ids);
1420
1421static struct usb_driver usblp_driver = {
1422	.name =		"usblp",
1423	.probe =	usblp_probe,
1424	.disconnect =	usblp_disconnect,
1425	.suspend =	usblp_suspend,
1426	.resume =	usblp_resume,
1427	.id_table =	usblp_ids,
1428	.dev_groups =	usblp_groups,
1429	.supports_autosuspend =	1,
1430};
1431
1432module_usb_driver(usblp_driver);
1433
1434MODULE_AUTHOR(DRIVER_AUTHOR);
1435MODULE_DESCRIPTION(DRIVER_DESC);
1436module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1437MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1438MODULE_LICENSE("GPL");