xref: /openbmc/linux/drivers/usb/class/usblp.c (revision c21b37f6)
1 /*
2  * usblp.c
3  *
4  * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
5  * Copyright (c) 1999 Pavel Machek	<pavel@suse.cz>
6  * Copyright (c) 2000 Randy Dunlap	<rdunlap@xenotime.net>
7  * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
8  # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
9  # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
10  * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>
11  *
12  * USB Printer Device Class driver for USB printers and printer cables
13  *
14  * Sponsored by SuSE
15  *
16  * ChangeLog:
17  *	v0.1 - thorough cleaning, URBification, almost a rewrite
18  *	v0.2 - some more cleanups
19  *	v0.3 - cleaner again, waitqueue fixes
20  *	v0.4 - fixes in unidirectional mode
21  *	v0.5 - add DEVICE_ID string support
22  *	v0.6 - never time out
23  *	v0.7 - fixed bulk-IN read and poll (David Paschal)
24  *	v0.8 - add devfs support
25  *	v0.9 - fix unplug-while-open paths
26  *	v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
27  *	v0.11 - add proto_bias option (Pete Zaitcev)
28  *	v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
29  *	v0.13 - alloc space for statusbuf (<status> not on stack);
30  *		use usb_buffer_alloc() for read buf & write buf;
31  */
32 
33 /*
34  * This program is free software; you can redistribute it and/or modify
35  * it under the terms of the GNU General Public License as published by
36  * the Free Software Foundation; either version 2 of the License, or
37  * (at your option) any later version.
38  *
39  * This program is distributed in the hope that it will be useful,
40  * but WITHOUT ANY WARRANTY; without even the implied warranty of
41  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
42  * GNU General Public License for more details.
43  *
44  * You should have received a copy of the GNU General Public License
45  * along with this program; if not, write to the Free Software
46  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
47  */
48 
49 #include <linux/module.h>
50 #include <linux/kernel.h>
51 #include <linux/sched.h>
52 #include <linux/signal.h>
53 #include <linux/poll.h>
54 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/lp.h>
57 #include <linux/mutex.h>
58 #undef DEBUG
59 #include <linux/usb.h>
60 
61 /*
62  * Version Information
63  */
64 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
65 #define DRIVER_DESC "USB Printer Device Class driver"
66 
67 #define USBLP_BUF_SIZE		8192
68 #define USBLP_BUF_SIZE_IN	1024
69 #define USBLP_DEVICE_ID_SIZE	1024
70 
71 /* ioctls: */
72 #define LPGETSTATUS		0x060b		/* same as in drivers/char/lp.c */
73 #define IOCNR_GET_DEVICE_ID		1
74 #define IOCNR_GET_PROTOCOLS		2
75 #define IOCNR_SET_PROTOCOL		3
76 #define IOCNR_HP_SET_CHANNEL		4
77 #define IOCNR_GET_BUS_ADDRESS		5
78 #define IOCNR_GET_VID_PID		6
79 #define IOCNR_SOFT_RESET		7
80 /* Get device_id string: */
81 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
82 /* The following ioctls were added for http://hpoj.sourceforge.net: */
83 /* Get two-int array:
84  * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
85  * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
86 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
87 /* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
88 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
89 /* Set channel number (HP Vendor-specific command): */
90 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
91 /* Get two-int array: [0]=bus number, [1]=device address: */
92 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
93 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
94 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
95 /* Perform class specific soft reset */
96 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
97 
98 /*
99  * A DEVICE_ID string may include the printer's serial number.
100  * It should end with a semi-colon (';').
101  * An example from an HP 970C DeskJet printer is (this is one long string,
102  * with the serial number changed):
103 MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
104  */
105 
106 /*
107  * USB Printer Requests
108  */
109 
110 #define USBLP_REQ_GET_ID			0x00
111 #define USBLP_REQ_GET_STATUS			0x01
112 #define USBLP_REQ_RESET				0x02
113 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST	0x00	/* HP Vendor-specific */
114 
115 #define USBLP_MINORS		16
116 #define USBLP_MINOR_BASE	0
117 
118 #define USBLP_WRITE_TIMEOUT	(5000)			/* 5 seconds */
119 
120 #define USBLP_FIRST_PROTOCOL	1
121 #define USBLP_LAST_PROTOCOL	3
122 #define USBLP_MAX_PROTOCOLS	(USBLP_LAST_PROTOCOL+1)
123 
124 /*
125  * some arbitrary status buffer size;
126  * need a status buffer that is allocated via kmalloc(), not on stack
127  */
128 #define STATUS_BUF_SIZE		8
129 
130 /*
131  * Locks down the locking order:
132  * ->wmut locks wstatus.
133  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
134  * [rw]status. We only touch status when we know the side idle.
135  * ->lock locks what interrupt accesses.
136  */
137 struct usblp {
138 	struct usb_device 	*dev;			/* USB device */
139 	struct mutex		wmut;
140 	struct mutex		mut;
141 	spinlock_t		lock;		/* locks rcomplete, wcomplete */
142 	char			*readbuf;		/* read transfer_buffer */
143 	char			*statusbuf;		/* status transfer_buffer */
144 	struct usb_anchor	urbs;
145 	wait_queue_head_t	rwait, wwait;
146 	int			readcount;		/* Counter for reads */
147 	int			ifnum;			/* Interface number */
148 	struct usb_interface	*intf;			/* The interface */
149 	/* Alternate-setting numbers and endpoints for each protocol
150 	 * (7/1/{index=1,2,3}) that the device supports: */
151 	struct {
152 		int				alt_setting;
153 		struct usb_endpoint_descriptor	*epwrite;
154 		struct usb_endpoint_descriptor	*epread;
155 	}			protocol[USBLP_MAX_PROTOCOLS];
156 	int			current_protocol;
157 	int			minor;			/* minor number of device */
158 	int			wcomplete, rcomplete;
159 	int			wstatus;	/* bytes written or error */
160 	int			rstatus;	/* bytes ready or error */
161 	unsigned int		quirks;			/* quirks flags */
162 	unsigned char		used;			/* True if open */
163 	unsigned char		present;		/* True if not disconnected */
164 	unsigned char		bidir;			/* interface is bidirectional */
165 	unsigned char		sleeping;		/* interface is suspended */
166 	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
167 							/* first 2 bytes are (big-endian) length */
168 };
169 
170 #ifdef DEBUG
171 static void usblp_dump(struct usblp *usblp) {
172 	int p;
173 
174 	dbg("usblp=0x%p", usblp);
175 	dbg("dev=0x%p", usblp->dev);
176 	dbg("present=%d", usblp->present);
177 	dbg("readbuf=0x%p", usblp->readbuf);
178 	dbg("readcount=%d", usblp->readcount);
179 	dbg("ifnum=%d", usblp->ifnum);
180     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
181 	dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
182 	dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
183 	dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
184     }
185 	dbg("current_protocol=%d", usblp->current_protocol);
186 	dbg("minor=%d", usblp->minor);
187 	dbg("wstatus=%d", usblp->wstatus);
188 	dbg("rstatus=%d", usblp->rstatus);
189 	dbg("quirks=%d", usblp->quirks);
190 	dbg("used=%d", usblp->used);
191 	dbg("bidir=%d", usblp->bidir);
192 	dbg("sleeping=%d", usblp->sleeping);
193 	dbg("device_id_string=\"%s\"",
194 		usblp->device_id_string ?
195 			usblp->device_id_string + 2 :
196 			(unsigned char *)"(null)");
197 }
198 #endif
199 
200 /* Quirks: various printer quirks are handled by this table & its flags. */
201 
202 struct quirk_printer_struct {
203 	__u16 vendorId;
204 	__u16 productId;
205 	unsigned int quirks;
206 };
207 
208 #define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
209 #define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
210 #define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */
211 
212 static const struct quirk_printer_struct quirk_printers[] = {
213 	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
214 	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
215 	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
216 	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
217 	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
218 	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
219 	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
220 	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
221 	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
222 	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
223 	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
224 	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
225 	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
226 	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
227 	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
228 	{ 0, 0 }
229 };
230 
231 static int usblp_wwait(struct usblp *usblp, int nonblock);
232 static int usblp_wtest(struct usblp *usblp, int nonblock);
233 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
234 static int usblp_rtest(struct usblp *usblp, int nonblock);
235 static int usblp_submit_read(struct usblp *usblp);
236 static int usblp_select_alts(struct usblp *usblp);
237 static int usblp_set_protocol(struct usblp *usblp, int protocol);
238 static int usblp_cache_device_id_string(struct usblp *usblp);
239 
240 /* forward reference to make our lives easier */
241 static struct usb_driver usblp_driver;
242 static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
243 
244 /*
245  * Functions for usblp control messages.
246  */
247 
248 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
249 {
250 	int retval;
251 	int index = usblp->ifnum;
252 
253 	/* High byte has the interface index.
254 	   Low byte has the alternate setting.
255 	 */
256 	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
257 	  index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
258 	}
259 
260 	retval = usb_control_msg(usblp->dev,
261 		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
262 		request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
263 	dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
264 		request, !!dir, recip, value, index, len, retval);
265 	return retval < 0 ? retval : 0;
266 }
267 
268 #define usblp_read_status(usblp, status)\
269 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
270 #define usblp_get_id(usblp, config, id, maxlen)\
271 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
272 #define usblp_reset(usblp)\
273 	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
274 
275 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
276 	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
277 
278 /*
279  * See the description for usblp_select_alts() below for the usage
280  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
281  * case of any trouble.
282  */
283 static int proto_bias = -1;
284 
285 /*
286  * URB callback.
287  */
288 
289 static void usblp_bulk_read(struct urb *urb)
290 {
291 	struct usblp *usblp = urb->context;
292 	int status = urb->status;
293 
294 	if (usblp->present && usblp->used) {
295 		if (status)
296 			printk(KERN_WARNING "usblp%d: "
297 			    "nonzero read bulk status received: %d\n",
298 			    usblp->minor, status);
299 	}
300 	spin_lock(&usblp->lock);
301 	if (status < 0)
302 		usblp->rstatus = status;
303 	else
304 		usblp->rstatus = urb->actual_length;
305 	usblp->rcomplete = 1;
306 	wake_up(&usblp->rwait);
307 	spin_unlock(&usblp->lock);
308 
309 	usb_free_urb(urb);
310 }
311 
312 static void usblp_bulk_write(struct urb *urb)
313 {
314 	struct usblp *usblp = urb->context;
315 	int status = urb->status;
316 
317 	if (usblp->present && usblp->used) {
318 		if (status)
319 			printk(KERN_WARNING "usblp%d: "
320 			    "nonzero write bulk status received: %d\n",
321 			    usblp->minor, status);
322 	}
323 	spin_lock(&usblp->lock);
324 	if (status < 0)
325 		usblp->wstatus = status;
326 	else
327 		usblp->wstatus = urb->actual_length;
328 	usblp->wcomplete = 1;
329 	wake_up(&usblp->wwait);
330 	spin_unlock(&usblp->lock);
331 
332 	/* XXX Use usb_setup_bulk_urb when available. Talk to Marcel. */
333 	kfree(urb->transfer_buffer);
334 	urb->transfer_buffer = NULL;	/* Not refcounted, so to be safe... */
335 	usb_free_urb(urb);
336 }
337 
338 /*
339  * Get and print printer errors.
340  */
341 
342 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
343 
344 static int usblp_check_status(struct usblp *usblp, int err)
345 {
346 	unsigned char status, newerr = 0;
347 	int error;
348 
349 	error = usblp_read_status (usblp, usblp->statusbuf);
350 	if (error < 0) {
351 		if (printk_ratelimit())
352 			printk(KERN_ERR
353 				"usblp%d: error %d reading printer status\n",
354 				usblp->minor, error);
355 		return 0;
356 	}
357 
358 	status = *usblp->statusbuf;
359 
360 	if (~status & LP_PERRORP)
361 		newerr = 3;
362 	if (status & LP_POUTPA)
363 		newerr = 1;
364 	if (~status & LP_PSELECD)
365 		newerr = 2;
366 
367 	if (newerr != err) {
368 		printk(KERN_INFO "usblp%d: %s\n",
369 		   usblp->minor, usblp_messages[newerr]);
370 	}
371 
372 	return newerr;
373 }
374 
375 static int handle_bidir (struct usblp *usblp)
376 {
377 	if (usblp->bidir && usblp->used && !usblp->sleeping) {
378 		if (usblp_submit_read(usblp) < 0)
379 			return -EIO;
380 	}
381 	return 0;
382 }
383 
384 /*
385  * File op functions.
386  */
387 
388 static int usblp_open(struct inode *inode, struct file *file)
389 {
390 	int minor = iminor(inode);
391 	struct usblp *usblp;
392 	struct usb_interface *intf;
393 	int retval;
394 
395 	if (minor < 0)
396 		return -ENODEV;
397 
398 	mutex_lock (&usblp_mutex);
399 
400 	retval = -ENODEV;
401 	intf = usb_find_interface(&usblp_driver, minor);
402 	if (!intf) {
403 		goto out;
404 	}
405 	usblp = usb_get_intfdata (intf);
406 	if (!usblp || !usblp->dev || !usblp->present)
407 		goto out;
408 
409 	retval = -EBUSY;
410 	if (usblp->used)
411 		goto out;
412 
413 	/*
414 	 * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
415 	 * This is #if 0-ed because we *don't* want to fail an open
416 	 * just because the printer is off-line.
417 	 */
418 #if 0
419 	if ((retval = usblp_check_status(usblp, 0))) {
420 		retval = retval > 1 ? -EIO : -ENOSPC;
421 		goto out;
422 	}
423 #else
424 	retval = 0;
425 #endif
426 
427 	retval = usb_autopm_get_interface(intf);
428 	if (retval < 0)
429 		goto out;
430 	usblp->used = 1;
431 	file->private_data = usblp;
432 
433 	usblp->wcomplete = 1; /* we begin writeable */
434 	usblp->wstatus = 0;
435 	usblp->rcomplete = 0;
436 
437 	if (handle_bidir(usblp) < 0) {
438 		usblp->used = 0;
439 		file->private_data = NULL;
440 		retval = -EIO;
441 	}
442 out:
443 	mutex_unlock (&usblp_mutex);
444 	return retval;
445 }
446 
447 static void usblp_cleanup (struct usblp *usblp)
448 {
449 	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
450 
451 	kfree(usblp->readbuf);
452 	kfree (usblp->device_id_string);
453 	kfree (usblp->statusbuf);
454 	kfree (usblp);
455 }
456 
457 static void usblp_unlink_urbs(struct usblp *usblp)
458 {
459 	usb_kill_anchored_urbs(&usblp->urbs);
460 }
461 
462 static int usblp_release(struct inode *inode, struct file *file)
463 {
464 	struct usblp *usblp = file->private_data;
465 
466 	mutex_lock (&usblp_mutex);
467 	usblp->used = 0;
468 	if (usblp->present) {
469 		usblp_unlink_urbs(usblp);
470 		usb_autopm_put_interface(usblp->intf);
471 	} else 		/* finish cleanup from disconnect */
472 		usblp_cleanup (usblp);
473 	mutex_unlock (&usblp_mutex);
474 	return 0;
475 }
476 
477 /* No kernel lock - fine */
478 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
479 {
480 	int ret;
481 	unsigned long flags;
482 
483 	struct usblp *usblp = file->private_data;
484 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
485 	poll_wait(file, &usblp->rwait, wait);
486 	poll_wait(file, &usblp->wwait, wait);
487 	spin_lock_irqsave(&usblp->lock, flags);
488 	ret = ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
489  			       | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
490 	spin_unlock_irqrestore(&usblp->lock, flags);
491 	return ret;
492 }
493 
494 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
495 {
496 	struct usblp *usblp = file->private_data;
497 	int length, err, i;
498 	unsigned char newChannel;
499 	int status;
500 	int twoints[2];
501 	int retval = 0;
502 
503 	mutex_lock (&usblp->mut);
504 	if (!usblp->present) {
505 		retval = -ENODEV;
506 		goto done;
507 	}
508 
509 	if (usblp->sleeping) {
510 		retval = -ENODEV;
511 		goto done;
512 	}
513 
514 	dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
515 		_IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );
516 
517 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
518 
519 		switch (_IOC_NR(cmd)) {
520 
521 			case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
522 				if (_IOC_DIR(cmd) != _IOC_READ) {
523 					retval = -EINVAL;
524 					goto done;
525 				}
526 
527 				length = usblp_cache_device_id_string(usblp);
528 				if (length < 0) {
529 					retval = length;
530 					goto done;
531 				}
532 				if (length > _IOC_SIZE(cmd))
533 					length = _IOC_SIZE(cmd); /* truncate */
534 
535 				if (copy_to_user((void __user *) arg,
536 						usblp->device_id_string,
537 						(unsigned long) length)) {
538 					retval = -EFAULT;
539 					goto done;
540 				}
541 
542 				break;
543 
544 			case IOCNR_GET_PROTOCOLS:
545 				if (_IOC_DIR(cmd) != _IOC_READ ||
546 				    _IOC_SIZE(cmd) < sizeof(twoints)) {
547 					retval = -EINVAL;
548 					goto done;
549 				}
550 
551 				twoints[0] = usblp->current_protocol;
552 				twoints[1] = 0;
553 				for (i = USBLP_FIRST_PROTOCOL;
554 				     i <= USBLP_LAST_PROTOCOL; i++) {
555 					if (usblp->protocol[i].alt_setting >= 0)
556 						twoints[1] |= (1<<i);
557 				}
558 
559 				if (copy_to_user((void __user *)arg,
560 						(unsigned char *)twoints,
561 						sizeof(twoints))) {
562 					retval = -EFAULT;
563 					goto done;
564 				}
565 
566 				break;
567 
568 			case IOCNR_SET_PROTOCOL:
569 				if (_IOC_DIR(cmd) != _IOC_WRITE) {
570 					retval = -EINVAL;
571 					goto done;
572 				}
573 
574 #ifdef DEBUG
575 				if (arg == -10) {
576 					usblp_dump(usblp);
577 					break;
578 				}
579 #endif
580 
581 				usblp_unlink_urbs(usblp);
582 				retval = usblp_set_protocol(usblp, arg);
583 				if (retval < 0) {
584 					usblp_set_protocol(usblp,
585 						usblp->current_protocol);
586 				}
587 				break;
588 
589 			case IOCNR_HP_SET_CHANNEL:
590 				if (_IOC_DIR(cmd) != _IOC_WRITE ||
591 				    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
592 				    usblp->quirks & USBLP_QUIRK_BIDIR) {
593 					retval = -EINVAL;
594 					goto done;
595 				}
596 
597 				err = usblp_hp_channel_change_request(usblp,
598 					arg, &newChannel);
599 				if (err < 0) {
600 					err("usblp%d: error = %d setting "
601 						"HP channel",
602 						usblp->minor, err);
603 					retval = -EIO;
604 					goto done;
605 				}
606 
607 				dbg("usblp%d requested/got HP channel %ld/%d",
608 					usblp->minor, arg, newChannel);
609 				break;
610 
611 			case IOCNR_GET_BUS_ADDRESS:
612 				if (_IOC_DIR(cmd) != _IOC_READ ||
613 				    _IOC_SIZE(cmd) < sizeof(twoints)) {
614 					retval = -EINVAL;
615 					goto done;
616 				}
617 
618 				twoints[0] = usblp->dev->bus->busnum;
619 				twoints[1] = usblp->dev->devnum;
620 				if (copy_to_user((void __user *)arg,
621 						(unsigned char *)twoints,
622 						sizeof(twoints))) {
623 					retval = -EFAULT;
624 					goto done;
625 				}
626 
627 				dbg("usblp%d is bus=%d, device=%d",
628 					usblp->minor, twoints[0], twoints[1]);
629 				break;
630 
631 			case IOCNR_GET_VID_PID:
632 				if (_IOC_DIR(cmd) != _IOC_READ ||
633 				    _IOC_SIZE(cmd) < sizeof(twoints)) {
634 					retval = -EINVAL;
635 					goto done;
636 				}
637 
638 				twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
639 				twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
640 				if (copy_to_user((void __user *)arg,
641 						(unsigned char *)twoints,
642 						sizeof(twoints))) {
643 					retval = -EFAULT;
644 					goto done;
645 				}
646 
647 				dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
648 					usblp->minor, twoints[0], twoints[1]);
649 				break;
650 
651 			case IOCNR_SOFT_RESET:
652 				if (_IOC_DIR(cmd) != _IOC_NONE) {
653 					retval = -EINVAL;
654 					goto done;
655 				}
656 				retval = usblp_reset(usblp);
657 				break;
658 			default:
659 				retval = -ENOTTY;
660 		}
661 	else	/* old-style ioctl value */
662 		switch (cmd) {
663 
664 			case LPGETSTATUS:
665 				if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
666 					if (printk_ratelimit())
667 						printk(KERN_ERR "usblp%d:"
668 						    "failed reading printer status (%d)\n",
669 						    usblp->minor, retval);
670 					retval = -EIO;
671 					goto done;
672 				}
673 				status = *usblp->statusbuf;
674 				if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
675 					retval = -EFAULT;
676 				break;
677 
678 			default:
679 				retval = -ENOTTY;
680 		}
681 
682 done:
683 	mutex_unlock (&usblp->mut);
684 	return retval;
685 }
686 
687 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
688 {
689 	struct usblp *usblp = file->private_data;
690 	char *writebuf;
691 	struct urb *writeurb;
692 	int rv;
693 	int transfer_length;
694 	ssize_t writecount = 0;
695 
696 	if (mutex_lock_interruptible(&usblp->wmut)) {
697 		rv = -EINTR;
698 		goto raise_biglock;
699 	}
700 	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
701 		goto raise_wait;
702 
703 	while (writecount < count) {
704 		/*
705 		 * Step 1: Submit next block.
706 		 */
707 		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
708 			transfer_length = USBLP_BUF_SIZE;
709 
710 		rv = -ENOMEM;
711 		if ((writebuf = kmalloc(USBLP_BUF_SIZE, GFP_KERNEL)) == NULL)
712 			goto raise_buf;
713 		if ((writeurb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
714 			goto raise_urb;
715 		usb_fill_bulk_urb(writeurb, usblp->dev,
716 			usb_sndbulkpipe(usblp->dev,
717 			  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
718 			writebuf, transfer_length, usblp_bulk_write, usblp);
719 		usb_anchor_urb(writeurb, &usblp->urbs);
720 
721 		if (copy_from_user(writebuf,
722 				   buffer + writecount, transfer_length)) {
723 			rv = -EFAULT;
724 			goto raise_badaddr;
725 		}
726 
727 		spin_lock_irq(&usblp->lock);
728 		usblp->wcomplete = 0;
729 		spin_unlock_irq(&usblp->lock);
730 		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
731 			usblp->wstatus = 0;
732 			spin_lock_irq(&usblp->lock);
733 			usblp->wcomplete = 1;
734 			wake_up(&usblp->wwait);
735 			spin_unlock_irq(&usblp->lock);
736 			if (rv != -ENOMEM)
737 				rv = -EIO;
738 			goto raise_submit;
739 		}
740 
741 		/*
742 		 * Step 2: Wait for transfer to end, collect results.
743 		 */
744 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
745 		if (rv < 0) {
746 			if (rv == -EAGAIN) {
747 				/* Presume that it's going to complete well. */
748 				writecount += transfer_length;
749 			}
750 			/* Leave URB dangling, to be cleaned on close. */
751 			goto collect_error;
752 		}
753 
754 		if (usblp->wstatus < 0) {
755 			usblp_check_status(usblp, 0);
756 			rv = -EIO;
757 			goto collect_error;
758 		}
759 		/*
760 		 * This is critical: it must be our URB, not other writer's.
761 		 * The wmut exists mainly to cover us here.
762 		 */
763 		writecount += usblp->wstatus;
764 	}
765 
766 	mutex_unlock(&usblp->wmut);
767 	return writecount;
768 
769 raise_submit:
770 raise_badaddr:
771 	usb_unanchor_urb(writeurb);
772 	usb_free_urb(writeurb);
773 raise_urb:
774 	kfree(writebuf);
775 raise_buf:
776 raise_wait:
777 collect_error:		/* Out of raise sequence */
778 	mutex_unlock(&usblp->wmut);
779 raise_biglock:
780 	return writecount ? writecount : rv;
781 }
782 
783 /*
784  * Notice that we fail to restart in a few cases: on EFAULT, on restart
785  * error, etc. This is the historical behaviour. In all such cases we return
786  * EIO, and applications loop in order to get the new read going.
787  */
788 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
789 {
790 	struct usblp *usblp = file->private_data;
791 	ssize_t count;
792 	ssize_t avail;
793 	int rv;
794 
795 	if (!usblp->bidir)
796 		return -EINVAL;
797 
798 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
799 	if (rv < 0)
800 		return rv;
801 
802 	if ((avail = usblp->rstatus) < 0) {
803 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
804 		    usblp->minor, (int)avail);
805 		usblp_submit_read(usblp);
806 		count = -EIO;
807 		goto done;
808 	}
809 
810 	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
811 	if (count != 0 &&
812 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
813 		count = -EFAULT;
814 		goto done;
815 	}
816 
817 	if ((usblp->readcount += count) == avail) {
818 		if (usblp_submit_read(usblp) < 0) {
819 			/* We don't want to leak USB return codes into errno. */
820 			if (count == 0)
821 				count = -EIO;
822 			goto done;
823 		}
824 	}
825 
826 done:
827 	mutex_unlock (&usblp->mut);
828 	return count;
829 }
830 
831 /*
832  * Wait for the write path to come idle.
833  * This is called under the ->wmut, so the idle path stays idle.
834  *
835  * Our write path has a peculiar property: it does not buffer like a tty,
836  * but waits for the write to succeed. This allows our ->release to bug out
837  * without waiting for writes to drain. But it obviously does not work
838  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
839  * select(2) or poll(2) to wait for the buffer to drain before closing.
840  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
841  *
842  * Old v0.13 code had a non-functional timeout for wait_event(). Someone forgot
843  * to check the return code for timeout expiration, so it had no effect.
844  * Apparently, it was intended to check for error conditons, such as out
845  * of paper. It is going to return when we settle things with CUPS. XXX
846  */
847 static int usblp_wwait(struct usblp *usblp, int nonblock)
848 {
849 	DECLARE_WAITQUEUE(waita, current);
850 	int rc;
851 
852 	add_wait_queue(&usblp->wwait, &waita);
853 	for (;;) {
854 		if (mutex_lock_interruptible(&usblp->mut)) {
855 			rc = -EINTR;
856 			break;
857 		}
858 		set_current_state(TASK_INTERRUPTIBLE);
859 		if ((rc = usblp_wtest(usblp, nonblock)) < 0) {
860 			mutex_unlock(&usblp->mut);
861 			break;
862 		}
863 		mutex_unlock(&usblp->mut);
864 		if (rc == 0)
865 			break;
866 		schedule();
867 	}
868 	set_current_state(TASK_RUNNING);
869 	remove_wait_queue(&usblp->wwait, &waita);
870 	return rc;
871 }
872 
873 static int usblp_wtest(struct usblp *usblp, int nonblock)
874 {
875 	unsigned long flags;
876 
877 	if (!usblp->present)
878 		return -ENODEV;
879 	if (signal_pending(current))
880 		return -EINTR;
881 	spin_lock_irqsave(&usblp->lock, flags);
882 	if (usblp->wcomplete) {
883 		spin_unlock_irqrestore(&usblp->lock, flags);
884 		return 0;
885 	}
886 	spin_unlock_irqrestore(&usblp->lock, flags);
887 	if (usblp->sleeping)
888 		return -ENODEV;
889 	if (nonblock)
890 		return -EAGAIN;
891 	return 1;
892 }
893 
894 /*
895  * Wait for read bytes to become available. This probably should have been
896  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
897  * name for functions which lock and return.
898  *
899  * We do not use wait_event_interruptible because it makes locking iffy.
900  */
901 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
902 {
903 	DECLARE_WAITQUEUE(waita, current);
904 	int rc;
905 
906 	add_wait_queue(&usblp->rwait, &waita);
907 	for (;;) {
908 		if (mutex_lock_interruptible(&usblp->mut)) {
909 			rc = -EINTR;
910 			break;
911 		}
912 		set_current_state(TASK_INTERRUPTIBLE);
913 		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
914 			mutex_unlock(&usblp->mut);
915 			break;
916 		}
917 		if (rc == 0)	/* Keep it locked */
918 			break;
919 		mutex_unlock(&usblp->mut);
920 		schedule();
921 	}
922 	set_current_state(TASK_RUNNING);
923 	remove_wait_queue(&usblp->rwait, &waita);
924 	return rc;
925 }
926 
927 static int usblp_rtest(struct usblp *usblp, int nonblock)
928 {
929 	unsigned long flags;
930 
931 	if (!usblp->present)
932 		return -ENODEV;
933 	if (signal_pending(current))
934 		return -EINTR;
935 	spin_lock_irqsave(&usblp->lock, flags);
936 	if (usblp->rcomplete) {
937 		spin_unlock_irqrestore(&usblp->lock, flags);
938 		return 0;
939 	}
940 	spin_unlock_irqrestore(&usblp->lock, flags);
941 	if (usblp->sleeping)
942 		return -ENODEV;
943 	if (nonblock)
944 		return -EAGAIN;
945 	return 1;
946 }
947 
948 /*
949  * Please check ->bidir and other such things outside for now.
950  */
951 static int usblp_submit_read(struct usblp *usblp)
952 {
953 	struct urb *urb;
954 	unsigned long flags;
955 	int rc;
956 
957 	rc = -ENOMEM;
958 	if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
959 		goto raise_urb;
960 
961 	usb_fill_bulk_urb(urb, usblp->dev,
962 		usb_rcvbulkpipe(usblp->dev,
963 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
964 		usblp->readbuf, USBLP_BUF_SIZE_IN,
965 		usblp_bulk_read, usblp);
966 	usb_anchor_urb(urb, &usblp->urbs);
967 
968 	spin_lock_irqsave(&usblp->lock, flags);
969 	usblp->readcount = 0; /* XXX Why here? */
970 	usblp->rcomplete = 0;
971 	spin_unlock_irqrestore(&usblp->lock, flags);
972 	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
973 		dbg("error submitting urb (%d)", rc);
974 		spin_lock_irqsave(&usblp->lock, flags);
975 		usblp->rstatus = rc;
976 		usblp->rcomplete = 1;
977 		spin_unlock_irqrestore(&usblp->lock, flags);
978 		goto raise_submit;
979 	}
980 
981 	return 0;
982 
983 raise_submit:
984 	usb_unanchor_urb(urb);
985 	usb_free_urb(urb);
986 raise_urb:
987 	return rc;
988 }
989 
990 /*
991  * Checks for printers that have quirks, such as requiring unidirectional
992  * communication but reporting bidirectional; currently some HP printers
993  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
994  * sent at each open (like some Epsons).
995  * Returns 1 if found, 0 if not found.
996  *
997  * HP recommended that we use the bidirectional interface but
998  * don't attempt any bulk IN transfers from the IN endpoint.
999  * Here's some more detail on the problem:
1000  * The problem is not that it isn't bidirectional though. The problem
1001  * is that if you request a device ID, or status information, while
1002  * the buffers are full, the return data will end up in the print data
1003  * buffer. For example if you make sure you never request the device ID
1004  * while you are sending print data, and you don't try to query the
1005  * printer status every couple of milliseconds, you will probably be OK.
1006  */
1007 static unsigned int usblp_quirks (__u16 vendor, __u16 product)
1008 {
1009 	int i;
1010 
1011 	for (i = 0; quirk_printers[i].vendorId; i++) {
1012 		if (vendor == quirk_printers[i].vendorId &&
1013 		    product == quirk_printers[i].productId)
1014 			return quirk_printers[i].quirks;
1015  	}
1016 	return 0;
1017 }
1018 
1019 static const struct file_operations usblp_fops = {
1020 	.owner =	THIS_MODULE,
1021 	.read =		usblp_read,
1022 	.write =	usblp_write,
1023 	.poll =		usblp_poll,
1024 	.unlocked_ioctl =	usblp_ioctl,
1025 	.compat_ioctl =		usblp_ioctl,
1026 	.open =		usblp_open,
1027 	.release =	usblp_release,
1028 };
1029 
1030 static struct usb_class_driver usblp_class = {
1031 	.name =		"lp%d",
1032 	.fops =		&usblp_fops,
1033 	.minor_base =	USBLP_MINOR_BASE,
1034 };
1035 
1036 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1037 {
1038 	struct usb_interface *intf = to_usb_interface(dev);
1039 	struct usblp *usblp = usb_get_intfdata (intf);
1040 
1041 	if (usblp->device_id_string[0] == 0 &&
1042 	    usblp->device_id_string[1] == 0)
1043 		return 0;
1044 
1045 	return sprintf(buf, "%s", usblp->device_id_string+2);
1046 }
1047 
1048 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1049 
1050 static int usblp_probe(struct usb_interface *intf,
1051 		       const struct usb_device_id *id)
1052 {
1053 	struct usb_device *dev = interface_to_usbdev (intf);
1054 	struct usblp *usblp = NULL;
1055 	int protocol;
1056 	int retval;
1057 
1058 	/* Malloc and start initializing usblp structure so we can use it
1059 	 * directly. */
1060 	if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
1061 		retval = -ENOMEM;
1062 		goto abort;
1063 	}
1064 	usblp->dev = dev;
1065 	mutex_init(&usblp->wmut);
1066 	mutex_init (&usblp->mut);
1067 	spin_lock_init(&usblp->lock);
1068 	init_waitqueue_head(&usblp->rwait);
1069 	init_waitqueue_head(&usblp->wwait);
1070 	init_usb_anchor(&usblp->urbs);
1071 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1072 	usblp->intf = intf;
1073 
1074 	/* Malloc device ID string buffer to the largest expected length,
1075 	 * since we can re-query it on an ioctl and a dynamic string
1076 	 * could change in length. */
1077 	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1078 		retval = -ENOMEM;
1079 		goto abort;
1080 	}
1081 
1082 	/*
1083 	 * Allocate read buffer. We somewhat wastefully
1084 	 * malloc both regardless of bidirectionality, because the
1085 	 * alternate setting can be changed later via an ioctl.
1086 	 */
1087 	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1088 		retval = -ENOMEM;
1089 		goto abort;
1090 	}
1091 
1092 	/* Allocate buffer for printer status */
1093 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1094 	if (!usblp->statusbuf) {
1095 		retval = -ENOMEM;
1096 		goto abort;
1097 	}
1098 
1099 	/* Lookup quirks for this printer. */
1100 	usblp->quirks = usblp_quirks(
1101 		le16_to_cpu(dev->descriptor.idVendor),
1102 		le16_to_cpu(dev->descriptor.idProduct));
1103 
1104 	/* Analyze and pick initial alternate settings and endpoints. */
1105 	protocol = usblp_select_alts(usblp);
1106 	if (protocol < 0) {
1107 		dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1108 			le16_to_cpu(dev->descriptor.idVendor),
1109 			le16_to_cpu(dev->descriptor.idProduct));
1110 		retval = -ENODEV;
1111 		goto abort;
1112 	}
1113 
1114 	/* Setup the selected alternate setting and endpoints. */
1115 	if (usblp_set_protocol(usblp, protocol) < 0) {
1116 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1117 		goto abort;
1118 	}
1119 
1120 	/* Retrieve and store the device ID string. */
1121 	usblp_cache_device_id_string(usblp);
1122 	retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1123 	if (retval)
1124 		goto abort_intfdata;
1125 
1126 #ifdef DEBUG
1127 	usblp_check_status(usblp, 0);
1128 #endif
1129 
1130 	usb_set_intfdata (intf, usblp);
1131 
1132 	usblp->present = 1;
1133 
1134 	retval = usb_register_dev(intf, &usblp_class);
1135 	if (retval) {
1136 		printk(KERN_ERR "usblp: Not able to get a minor"
1137 		    " (base %u, slice default): %d\n",
1138 		    USBLP_MINOR_BASE, retval);
1139 		goto abort_intfdata;
1140 	}
1141 	usblp->minor = intf->minor;
1142 	printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1143 		"if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1144 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1145 		usblp->ifnum,
1146 		usblp->protocol[usblp->current_protocol].alt_setting,
1147 		usblp->current_protocol,
1148 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1149 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1150 
1151 	return 0;
1152 
1153 abort_intfdata:
1154 	usb_set_intfdata (intf, NULL);
1155 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1156 abort:
1157 	if (usblp) {
1158 		kfree(usblp->readbuf);
1159 		kfree(usblp->statusbuf);
1160 		kfree(usblp->device_id_string);
1161 		kfree(usblp);
1162 	}
1163 	return retval;
1164 }
1165 
1166 /*
1167  * We are a "new" style driver with usb_device_id table,
1168  * but our requirements are too intricate for simple match to handle.
1169  *
1170  * The "proto_bias" option may be used to specify the preferred protocol
1171  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1172  * supports the preferred protocol, then we bind to it.
1173  *
1174  * The best interface for us is 7/1/2, because it is compatible
1175  * with a stream of characters. If we find it, we bind to it.
1176  *
1177  * Note that the people from hpoj.sourceforge.net need to be able to
1178  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1179  *
1180  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1181  * stream-compatible, because this matches the behaviour of the old code.
1182  *
1183  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1184  */
1185 static int usblp_select_alts(struct usblp *usblp)
1186 {
1187 	struct usb_interface *if_alt;
1188 	struct usb_host_interface *ifd;
1189 	struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1190 	int p, i, e;
1191 
1192 	if_alt = usblp->intf;
1193 
1194 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1195 		usblp->protocol[p].alt_setting = -1;
1196 
1197 	/* Find out what we have. */
1198 	for (i = 0; i < if_alt->num_altsetting; i++) {
1199 		ifd = &if_alt->altsetting[i];
1200 
1201 		if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1202 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1203 				continue;
1204 
1205 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1206 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1207 			continue;
1208 
1209 		/* Look for bulk OUT and IN endpoints. */
1210 		epwrite = epread = NULL;
1211 		for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1212 			epd = &ifd->endpoint[e].desc;
1213 
1214 			if (usb_endpoint_is_bulk_out(epd))
1215 				if (!epwrite)
1216 					epwrite = epd;
1217 
1218 			if (usb_endpoint_is_bulk_in(epd))
1219 				if (!epread)
1220 					epread = epd;
1221 		}
1222 
1223 		/* Ignore buggy hardware without the right endpoints. */
1224 		if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1225 			continue;
1226 
1227 		/* Turn off reads for 7/1/1 (unidirectional) interfaces
1228 		 * and buggy bidirectional printers. */
1229 		if (ifd->desc.bInterfaceProtocol == 1) {
1230 			epread = NULL;
1231 		} else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1232 			printk(KERN_INFO "usblp%d: Disabling reads from "
1233 			    "problematic bidirectional printer\n",
1234 			    usblp->minor);
1235 			epread = NULL;
1236 		}
1237 
1238 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1239 				ifd->desc.bAlternateSetting;
1240 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1241 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1242 	}
1243 
1244 	/* If our requested protocol is supported, then use it. */
1245 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1246 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1247 	    usblp->protocol[proto_bias].alt_setting != -1)
1248 		return proto_bias;
1249 
1250 	/* Ordering is important here. */
1251 	if (usblp->protocol[2].alt_setting != -1)
1252 		return 2;
1253 	if (usblp->protocol[1].alt_setting != -1)
1254 		return 1;
1255 	if (usblp->protocol[3].alt_setting != -1)
1256 		return 3;
1257 
1258 	/* If nothing is available, then don't bind to this device. */
1259 	return -1;
1260 }
1261 
1262 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1263 {
1264 	int r, alts;
1265 
1266 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1267 		return -EINVAL;
1268 
1269 	alts = usblp->protocol[protocol].alt_setting;
1270 	if (alts < 0)
1271 		return -EINVAL;
1272 	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1273 	if (r < 0) {
1274 		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1275 			alts, usblp->ifnum);
1276 		return r;
1277 	}
1278 
1279 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1280 	usblp->current_protocol = protocol;
1281 	dbg("usblp%d set protocol %d", usblp->minor, protocol);
1282 	return 0;
1283 }
1284 
1285 /* Retrieves and caches device ID string.
1286  * Returns length, including length bytes but not null terminator.
1287  * On error, returns a negative errno value. */
1288 static int usblp_cache_device_id_string(struct usblp *usblp)
1289 {
1290 	int err, length;
1291 
1292 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1293 	if (err < 0) {
1294 		dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1295 			usblp->minor, err);
1296 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1297 		return -EIO;
1298 	}
1299 
1300 	/* First two bytes are length in big-endian.
1301 	 * They count themselves, and we copy them into
1302 	 * the user's buffer. */
1303 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1304 	if (length < 2)
1305 		length = 2;
1306 	else if (length >= USBLP_DEVICE_ID_SIZE)
1307 		length = USBLP_DEVICE_ID_SIZE - 1;
1308 	usblp->device_id_string[length] = '\0';
1309 
1310 	dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1311 		usblp->minor, length, &usblp->device_id_string[2]);
1312 
1313 	return length;
1314 }
1315 
1316 static void usblp_disconnect(struct usb_interface *intf)
1317 {
1318 	struct usblp *usblp = usb_get_intfdata (intf);
1319 
1320 	usb_deregister_dev(intf, &usblp_class);
1321 
1322 	if (!usblp || !usblp->dev) {
1323 		err("bogus disconnect");
1324 		BUG ();
1325 	}
1326 
1327 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1328 
1329 	mutex_lock (&usblp_mutex);
1330 	mutex_lock (&usblp->mut);
1331 	usblp->present = 0;
1332 	wake_up(&usblp->wwait);
1333 	wake_up(&usblp->rwait);
1334 	usb_set_intfdata (intf, NULL);
1335 
1336 	usblp_unlink_urbs(usblp);
1337 	mutex_unlock (&usblp->mut);
1338 
1339 	if (!usblp->used)
1340 		usblp_cleanup (usblp);
1341 	mutex_unlock (&usblp_mutex);
1342 }
1343 
1344 static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
1345 {
1346 	struct usblp *usblp = usb_get_intfdata (intf);
1347 
1348 	/* we take no more IO */
1349 	usblp->sleeping = 1;
1350 	usblp_unlink_urbs(usblp);
1351 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1352 	/* not strictly necessary, but just in case */
1353 	wake_up(&usblp->wwait);
1354 	wake_up(&usblp->rwait);
1355 #endif
1356 
1357 	return 0;
1358 }
1359 
1360 static int usblp_resume (struct usb_interface *intf)
1361 {
1362 	struct usblp *usblp = usb_get_intfdata (intf);
1363 	int r;
1364 
1365 	usblp->sleeping = 0;
1366 	r = handle_bidir (usblp);
1367 
1368 	return r;
1369 }
1370 
1371 static struct usb_device_id usblp_ids [] = {
1372 	{ USB_DEVICE_INFO(7, 1, 1) },
1373 	{ USB_DEVICE_INFO(7, 1, 2) },
1374 	{ USB_DEVICE_INFO(7, 1, 3) },
1375 	{ USB_INTERFACE_INFO(7, 1, 1) },
1376 	{ USB_INTERFACE_INFO(7, 1, 2) },
1377 	{ USB_INTERFACE_INFO(7, 1, 3) },
1378 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1379 	{ }						/* Terminating entry */
1380 };
1381 
1382 MODULE_DEVICE_TABLE (usb, usblp_ids);
1383 
1384 static struct usb_driver usblp_driver = {
1385 	.name =		"usblp",
1386 	.probe =	usblp_probe,
1387 	.disconnect =	usblp_disconnect,
1388 	.suspend =	usblp_suspend,
1389 	.resume =	usblp_resume,
1390 	.id_table =	usblp_ids,
1391 	.supports_autosuspend =	1,
1392 };
1393 
1394 static int __init usblp_init(void)
1395 {
1396 	return usb_register(&usblp_driver);
1397 }
1398 
1399 static void __exit usblp_exit(void)
1400 {
1401 	usb_deregister(&usblp_driver);
1402 }
1403 
1404 module_init(usblp_init);
1405 module_exit(usblp_exit);
1406 
1407 MODULE_AUTHOR( DRIVER_AUTHOR );
1408 MODULE_DESCRIPTION( DRIVER_DESC );
1409 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1410 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1411 MODULE_LICENSE("GPL");
1412