xref: /openbmc/linux/drivers/usb/class/usblp.c (revision d3597236)
1 /*
2  * usblp.c
3  *
4  * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
5  * Copyright (c) 1999 Pavel Machek	<pavel@ucw.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_alloc_coherent() for read buf & write buf;
31  *      none  - Maintained in Linux kernel after v0.13
32  */
33 
34 /*
35  * This program is free software; you can redistribute it and/or modify
36  * it under the terms of the GNU General Public License as published by
37  * the Free Software Foundation; either version 2 of the License, or
38  * (at your option) any later version.
39  *
40  * This program is distributed in the hope that it will be useful,
41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
43  * GNU General Public License for more details.
44  *
45  * You should have received a copy of the GNU General Public License
46  * along with this program; if not, write to the Free Software
47  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
48  */
49 
50 #include <linux/module.h>
51 #include <linux/kernel.h>
52 #include <linux/sched.h>
53 #include <linux/signal.h>
54 #include <linux/poll.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 #include <linux/ratelimit.h>
61 
62 /*
63  * Version Information
64  */
65 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
66 #define DRIVER_DESC "USB Printer Device Class driver"
67 
68 #define USBLP_BUF_SIZE		8192
69 #define USBLP_BUF_SIZE_IN	1024
70 #define USBLP_DEVICE_ID_SIZE	1024
71 
72 /* ioctls: */
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_CTL_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 int		flags;			/* mode flags */
163 	unsigned char		used;			/* True if open */
164 	unsigned char		present;		/* True if not disconnected */
165 	unsigned char		bidir;			/* interface is bidirectional */
166 	unsigned char		no_paper;		/* Paper Out happened */
167 	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
168 							/* first 2 bytes are (big-endian) length */
169 };
170 
171 #ifdef DEBUG
172 static void usblp_dump(struct usblp *usblp)
173 {
174 	struct device *dev = &usblp->intf->dev;
175 	int p;
176 
177 	dev_dbg(dev, "usblp=0x%p\n", usblp);
178 	dev_dbg(dev, "dev=0x%p\n", usblp->dev);
179 	dev_dbg(dev, "present=%d\n", usblp->present);
180 	dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
181 	dev_dbg(dev, "readcount=%d\n", usblp->readcount);
182 	dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
183 	for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
184 		dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
185 			usblp->protocol[p].alt_setting);
186 		dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
187 			usblp->protocol[p].epwrite);
188 		dev_dbg(dev, "protocol[%d].epread=%p\n", p,
189 			usblp->protocol[p].epread);
190 	}
191 	dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
192 	dev_dbg(dev, "minor=%d\n", usblp->minor);
193 	dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
194 	dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
195 	dev_dbg(dev, "quirks=%d\n", usblp->quirks);
196 	dev_dbg(dev, "used=%d\n", usblp->used);
197 	dev_dbg(dev, "bidir=%d\n", usblp->bidir);
198 	dev_dbg(dev, "device_id_string=\"%s\"\n",
199 		usblp->device_id_string ?
200 			usblp->device_id_string + 2 :
201 			(unsigned char *)"(null)");
202 }
203 #endif
204 
205 /* Quirks: various printer quirks are handled by this table & its flags. */
206 
207 struct quirk_printer_struct {
208 	__u16 vendorId;
209 	__u16 productId;
210 	unsigned int quirks;
211 };
212 
213 #define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
214 #define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
215 #define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */
216 
217 static const struct quirk_printer_struct quirk_printers[] = {
218 	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
219 	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
220 	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
221 	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
222 	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
223 	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
224 	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
225 	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
226 	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
227 	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
228 	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
229 	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
230 	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
231 	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
232 	{ 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
233 	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
234 	{ 0, 0 }
235 };
236 
237 static int usblp_wwait(struct usblp *usblp, int nonblock);
238 static int usblp_wtest(struct usblp *usblp, int nonblock);
239 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
240 static int usblp_rtest(struct usblp *usblp, int nonblock);
241 static int usblp_submit_read(struct usblp *usblp);
242 static int usblp_select_alts(struct usblp *usblp);
243 static int usblp_set_protocol(struct usblp *usblp, int protocol);
244 static int usblp_cache_device_id_string(struct usblp *usblp);
245 
246 /* forward reference to make our lives easier */
247 static struct usb_driver usblp_driver;
248 static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
249 
250 /*
251  * Functions for usblp control messages.
252  */
253 
254 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
255 {
256 	int retval;
257 	int index = usblp->ifnum;
258 
259 	/* High byte has the interface index.
260 	   Low byte has the alternate setting.
261 	 */
262 	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
263 		index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
264 
265 	retval = usb_control_msg(usblp->dev,
266 		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
267 		request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
268 	dev_dbg(&usblp->intf->dev,
269 		"usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
270 		request, !!dir, recip, value, index, len, retval);
271 	return retval < 0 ? retval : 0;
272 }
273 
274 #define usblp_read_status(usblp, status)\
275 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
276 #define usblp_get_id(usblp, config, id, maxlen)\
277 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
278 #define usblp_reset(usblp)\
279 	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
280 
281 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
282 	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
283 
284 /*
285  * See the description for usblp_select_alts() below for the usage
286  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
287  * case of any trouble.
288  */
289 static int proto_bias = -1;
290 
291 /*
292  * URB callback.
293  */
294 
295 static void usblp_bulk_read(struct urb *urb)
296 {
297 	struct usblp *usblp = urb->context;
298 	int status = urb->status;
299 
300 	if (usblp->present && usblp->used) {
301 		if (status)
302 			printk(KERN_WARNING "usblp%d: "
303 			    "nonzero read bulk status received: %d\n",
304 			    usblp->minor, status);
305 	}
306 	spin_lock(&usblp->lock);
307 	if (status < 0)
308 		usblp->rstatus = status;
309 	else
310 		usblp->rstatus = urb->actual_length;
311 	usblp->rcomplete = 1;
312 	wake_up(&usblp->rwait);
313 	spin_unlock(&usblp->lock);
314 
315 	usb_free_urb(urb);
316 }
317 
318 static void usblp_bulk_write(struct urb *urb)
319 {
320 	struct usblp *usblp = urb->context;
321 	int status = urb->status;
322 
323 	if (usblp->present && usblp->used) {
324 		if (status)
325 			printk(KERN_WARNING "usblp%d: "
326 			    "nonzero write bulk status received: %d\n",
327 			    usblp->minor, status);
328 	}
329 	spin_lock(&usblp->lock);
330 	if (status < 0)
331 		usblp->wstatus = status;
332 	else
333 		usblp->wstatus = urb->actual_length;
334 	usblp->no_paper = 0;
335 	usblp->wcomplete = 1;
336 	wake_up(&usblp->wwait);
337 	spin_unlock(&usblp->lock);
338 
339 	usb_free_urb(urb);
340 }
341 
342 /*
343  * Get and print printer errors.
344  */
345 
346 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
347 
348 static int usblp_check_status(struct usblp *usblp, int err)
349 {
350 	unsigned char status, newerr = 0;
351 	int error;
352 
353 	mutex_lock(&usblp->mut);
354 	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
355 		mutex_unlock(&usblp->mut);
356 		printk_ratelimited(KERN_ERR
357 				"usblp%d: error %d reading printer status\n",
358 				usblp->minor, error);
359 		return 0;
360 	}
361 	status = *usblp->statusbuf;
362 	mutex_unlock(&usblp->mut);
363 
364 	if (~status & LP_PERRORP)
365 		newerr = 3;
366 	if (status & LP_POUTPA)
367 		newerr = 1;
368 	if (~status & LP_PSELECD)
369 		newerr = 2;
370 
371 	if (newerr != err) {
372 		printk(KERN_INFO "usblp%d: %s\n",
373 		   usblp->minor, usblp_messages[newerr]);
374 	}
375 
376 	return newerr;
377 }
378 
379 static int handle_bidir(struct usblp *usblp)
380 {
381 	if (usblp->bidir && usblp->used) {
382 		if (usblp_submit_read(usblp) < 0)
383 			return -EIO;
384 	}
385 	return 0;
386 }
387 
388 /*
389  * File op functions.
390  */
391 
392 static int usblp_open(struct inode *inode, struct file *file)
393 {
394 	int minor = iminor(inode);
395 	struct usblp *usblp;
396 	struct usb_interface *intf;
397 	int retval;
398 
399 	if (minor < 0)
400 		return -ENODEV;
401 
402 	mutex_lock(&usblp_mutex);
403 
404 	retval = -ENODEV;
405 	intf = usb_find_interface(&usblp_driver, minor);
406 	if (!intf)
407 		goto out;
408 	usblp = usb_get_intfdata(intf);
409 	if (!usblp || !usblp->dev || !usblp->present)
410 		goto out;
411 
412 	retval = -EBUSY;
413 	if (usblp->used)
414 		goto out;
415 
416 	/*
417 	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
418 	 *  - We do not want persistent state which close(2) does not clear
419 	 *  - It is not used anyway, according to CUPS people
420 	 */
421 
422 	retval = usb_autopm_get_interface(intf);
423 	if (retval < 0)
424 		goto out;
425 	usblp->used = 1;
426 	file->private_data = usblp;
427 
428 	usblp->wcomplete = 1; /* we begin writeable */
429 	usblp->wstatus = 0;
430 	usblp->rcomplete = 0;
431 
432 	if (handle_bidir(usblp) < 0) {
433 		usb_autopm_put_interface(intf);
434 		usblp->used = 0;
435 		file->private_data = NULL;
436 		retval = -EIO;
437 	}
438 out:
439 	mutex_unlock(&usblp_mutex);
440 	return retval;
441 }
442 
443 static void usblp_cleanup(struct usblp *usblp)
444 {
445 	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
446 
447 	kfree(usblp->readbuf);
448 	kfree(usblp->device_id_string);
449 	kfree(usblp->statusbuf);
450 	kfree(usblp);
451 }
452 
453 static void usblp_unlink_urbs(struct usblp *usblp)
454 {
455 	usb_kill_anchored_urbs(&usblp->urbs);
456 }
457 
458 static int usblp_release(struct inode *inode, struct file *file)
459 {
460 	struct usblp *usblp = file->private_data;
461 
462 	usblp->flags &= ~LP_ABORT;
463 
464 	mutex_lock(&usblp_mutex);
465 	usblp->used = 0;
466 	if (usblp->present) {
467 		usblp_unlink_urbs(usblp);
468 		usb_autopm_put_interface(usblp->intf);
469 	} else		/* finish cleanup from disconnect */
470 		usblp_cleanup(usblp);
471 	mutex_unlock(&usblp_mutex);
472 	return 0;
473 }
474 
475 /* No kernel lock - fine */
476 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
477 {
478 	int ret;
479 	unsigned long flags;
480 
481 	struct usblp *usblp = file->private_data;
482 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
483 	poll_wait(file, &usblp->rwait, wait);
484 	poll_wait(file, &usblp->wwait, wait);
485 	spin_lock_irqsave(&usblp->lock, flags);
486 	ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
487 	   ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
488 	spin_unlock_irqrestore(&usblp->lock, flags);
489 	return ret;
490 }
491 
492 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
493 {
494 	struct usblp *usblp = file->private_data;
495 	int length, err, i;
496 	unsigned char newChannel;
497 	int status;
498 	int twoints[2];
499 	int retval = 0;
500 
501 	mutex_lock(&usblp->mut);
502 	if (!usblp->present) {
503 		retval = -ENODEV;
504 		goto done;
505 	}
506 
507 	dev_dbg(&usblp->intf->dev,
508 		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
509 		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
510 
511 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
512 
513 		switch (_IOC_NR(cmd)) {
514 
515 		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
516 			if (_IOC_DIR(cmd) != _IOC_READ) {
517 				retval = -EINVAL;
518 				goto done;
519 			}
520 
521 			length = usblp_cache_device_id_string(usblp);
522 			if (length < 0) {
523 				retval = length;
524 				goto done;
525 			}
526 			if (length > _IOC_SIZE(cmd))
527 				length = _IOC_SIZE(cmd); /* truncate */
528 
529 			if (copy_to_user((void __user *) arg,
530 					usblp->device_id_string,
531 					(unsigned long) length)) {
532 				retval = -EFAULT;
533 				goto done;
534 			}
535 
536 			break;
537 
538 		case IOCNR_GET_PROTOCOLS:
539 			if (_IOC_DIR(cmd) != _IOC_READ ||
540 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
541 				retval = -EINVAL;
542 				goto done;
543 			}
544 
545 			twoints[0] = usblp->current_protocol;
546 			twoints[1] = 0;
547 			for (i = USBLP_FIRST_PROTOCOL;
548 			     i <= USBLP_LAST_PROTOCOL; i++) {
549 				if (usblp->protocol[i].alt_setting >= 0)
550 					twoints[1] |= (1<<i);
551 			}
552 
553 			if (copy_to_user((void __user *)arg,
554 					(unsigned char *)twoints,
555 					sizeof(twoints))) {
556 				retval = -EFAULT;
557 				goto done;
558 			}
559 
560 			break;
561 
562 		case IOCNR_SET_PROTOCOL:
563 			if (_IOC_DIR(cmd) != _IOC_WRITE) {
564 				retval = -EINVAL;
565 				goto done;
566 			}
567 
568 #ifdef DEBUG
569 			if (arg == -10) {
570 				usblp_dump(usblp);
571 				break;
572 			}
573 #endif
574 
575 			usblp_unlink_urbs(usblp);
576 			retval = usblp_set_protocol(usblp, arg);
577 			if (retval < 0) {
578 				usblp_set_protocol(usblp,
579 					usblp->current_protocol);
580 			}
581 			break;
582 
583 		case IOCNR_HP_SET_CHANNEL:
584 			if (_IOC_DIR(cmd) != _IOC_WRITE ||
585 			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
586 			    usblp->quirks & USBLP_QUIRK_BIDIR) {
587 				retval = -EINVAL;
588 				goto done;
589 			}
590 
591 			err = usblp_hp_channel_change_request(usblp,
592 				arg, &newChannel);
593 			if (err < 0) {
594 				dev_err(&usblp->dev->dev,
595 					"usblp%d: error = %d setting "
596 					"HP channel\n",
597 					usblp->minor, err);
598 				retval = -EIO;
599 				goto done;
600 			}
601 
602 			dev_dbg(&usblp->intf->dev,
603 				"usblp%d requested/got HP channel %ld/%d\n",
604 				usblp->minor, arg, newChannel);
605 			break;
606 
607 		case IOCNR_GET_BUS_ADDRESS:
608 			if (_IOC_DIR(cmd) != _IOC_READ ||
609 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
610 				retval = -EINVAL;
611 				goto done;
612 			}
613 
614 			twoints[0] = usblp->dev->bus->busnum;
615 			twoints[1] = usblp->dev->devnum;
616 			if (copy_to_user((void __user *)arg,
617 					(unsigned char *)twoints,
618 					sizeof(twoints))) {
619 				retval = -EFAULT;
620 				goto done;
621 			}
622 
623 			dev_dbg(&usblp->intf->dev,
624 				"usblp%d is bus=%d, device=%d\n",
625 				usblp->minor, twoints[0], twoints[1]);
626 			break;
627 
628 		case IOCNR_GET_VID_PID:
629 			if (_IOC_DIR(cmd) != _IOC_READ ||
630 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
631 				retval = -EINVAL;
632 				goto done;
633 			}
634 
635 			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
636 			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
637 			if (copy_to_user((void __user *)arg,
638 					(unsigned char *)twoints,
639 					sizeof(twoints))) {
640 				retval = -EFAULT;
641 				goto done;
642 			}
643 
644 			dev_dbg(&usblp->intf->dev,
645 				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
646 				usblp->minor, twoints[0], twoints[1]);
647 			break;
648 
649 		case IOCNR_SOFT_RESET:
650 			if (_IOC_DIR(cmd) != _IOC_NONE) {
651 				retval = -EINVAL;
652 				goto done;
653 			}
654 			retval = usblp_reset(usblp);
655 			break;
656 		default:
657 			retval = -ENOTTY;
658 		}
659 	else	/* old-style ioctl value */
660 		switch (cmd) {
661 
662 		case LPGETSTATUS:
663 			retval = usblp_read_status(usblp, usblp->statusbuf);
664 			if (retval) {
665 				printk_ratelimited(KERN_ERR "usblp%d:"
666 					    "failed reading printer status (%d)\n",
667 					    usblp->minor, retval);
668 				retval = -EIO;
669 				goto done;
670 			}
671 			status = *usblp->statusbuf;
672 			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
673 				retval = -EFAULT;
674 			break;
675 
676 		case LPABORT:
677 			if (arg)
678 				usblp->flags |= LP_ABORT;
679 			else
680 				usblp->flags &= ~LP_ABORT;
681 			break;
682 
683 		default:
684 			retval = -ENOTTY;
685 		}
686 
687 done:
688 	mutex_unlock(&usblp->mut);
689 	return retval;
690 }
691 
692 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
693 {
694 	struct urb *urb;
695 	char *writebuf;
696 
697 	writebuf = kmalloc(transfer_length, GFP_KERNEL);
698 	if (writebuf == NULL)
699 		return NULL;
700 	urb = usb_alloc_urb(0, GFP_KERNEL);
701 	if (urb == NULL) {
702 		kfree(writebuf);
703 		return NULL;
704 	}
705 
706 	usb_fill_bulk_urb(urb, usblp->dev,
707 		usb_sndbulkpipe(usblp->dev,
708 		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
709 		writebuf, transfer_length, usblp_bulk_write, usblp);
710 	urb->transfer_flags |= URB_FREE_BUFFER;
711 
712 	return urb;
713 }
714 
715 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
716 {
717 	struct usblp *usblp = file->private_data;
718 	struct urb *writeurb;
719 	int rv;
720 	int transfer_length;
721 	ssize_t writecount = 0;
722 
723 	if (mutex_lock_interruptible(&usblp->wmut)) {
724 		rv = -EINTR;
725 		goto raise_biglock;
726 	}
727 	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
728 		goto raise_wait;
729 
730 	while (writecount < count) {
731 		/*
732 		 * Step 1: Submit next block.
733 		 */
734 		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
735 			transfer_length = USBLP_BUF_SIZE;
736 
737 		rv = -ENOMEM;
738 		writeurb = usblp_new_writeurb(usblp, transfer_length);
739 		if (writeurb == NULL)
740 			goto raise_urb;
741 		usb_anchor_urb(writeurb, &usblp->urbs);
742 
743 		if (copy_from_user(writeurb->transfer_buffer,
744 				   buffer + writecount, transfer_length)) {
745 			rv = -EFAULT;
746 			goto raise_badaddr;
747 		}
748 
749 		spin_lock_irq(&usblp->lock);
750 		usblp->wcomplete = 0;
751 		spin_unlock_irq(&usblp->lock);
752 		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
753 			usblp->wstatus = 0;
754 			spin_lock_irq(&usblp->lock);
755 			usblp->no_paper = 0;
756 			usblp->wcomplete = 1;
757 			wake_up(&usblp->wwait);
758 			spin_unlock_irq(&usblp->lock);
759 			if (rv != -ENOMEM)
760 				rv = -EIO;
761 			goto raise_submit;
762 		}
763 
764 		/*
765 		 * Step 2: Wait for transfer to end, collect results.
766 		 */
767 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
768 		if (rv < 0) {
769 			if (rv == -EAGAIN) {
770 				/* Presume that it's going to complete well. */
771 				writecount += transfer_length;
772 			}
773 			if (rv == -ENOSPC) {
774 				spin_lock_irq(&usblp->lock);
775 				usblp->no_paper = 1;	/* Mark for poll(2) */
776 				spin_unlock_irq(&usblp->lock);
777 				writecount += transfer_length;
778 			}
779 			/* Leave URB dangling, to be cleaned on close. */
780 			goto collect_error;
781 		}
782 
783 		if (usblp->wstatus < 0) {
784 			rv = -EIO;
785 			goto collect_error;
786 		}
787 		/*
788 		 * This is critical: it must be our URB, not other writer's.
789 		 * The wmut exists mainly to cover us here.
790 		 */
791 		writecount += usblp->wstatus;
792 	}
793 
794 	mutex_unlock(&usblp->wmut);
795 	return writecount;
796 
797 raise_submit:
798 raise_badaddr:
799 	usb_unanchor_urb(writeurb);
800 	usb_free_urb(writeurb);
801 raise_urb:
802 raise_wait:
803 collect_error:		/* Out of raise sequence */
804 	mutex_unlock(&usblp->wmut);
805 raise_biglock:
806 	return writecount ? writecount : rv;
807 }
808 
809 /*
810  * Notice that we fail to restart in a few cases: on EFAULT, on restart
811  * error, etc. This is the historical behaviour. In all such cases we return
812  * EIO, and applications loop in order to get the new read going.
813  */
814 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
815 {
816 	struct usblp *usblp = file->private_data;
817 	ssize_t count;
818 	ssize_t avail;
819 	int rv;
820 
821 	if (!usblp->bidir)
822 		return -EINVAL;
823 
824 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
825 	if (rv < 0)
826 		return rv;
827 
828 	if ((avail = usblp->rstatus) < 0) {
829 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
830 		    usblp->minor, (int)avail);
831 		usblp_submit_read(usblp);
832 		count = -EIO;
833 		goto done;
834 	}
835 
836 	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
837 	if (count != 0 &&
838 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
839 		count = -EFAULT;
840 		goto done;
841 	}
842 
843 	if ((usblp->readcount += count) == avail) {
844 		if (usblp_submit_read(usblp) < 0) {
845 			/* We don't want to leak USB return codes into errno. */
846 			if (count == 0)
847 				count = -EIO;
848 			goto done;
849 		}
850 	}
851 
852 done:
853 	mutex_unlock(&usblp->mut);
854 	return count;
855 }
856 
857 /*
858  * Wait for the write path to come idle.
859  * This is called under the ->wmut, so the idle path stays idle.
860  *
861  * Our write path has a peculiar property: it does not buffer like a tty,
862  * but waits for the write to succeed. This allows our ->release to bug out
863  * without waiting for writes to drain. But it obviously does not work
864  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
865  * select(2) or poll(2) to wait for the buffer to drain before closing.
866  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
867  */
868 static int usblp_wwait(struct usblp *usblp, int nonblock)
869 {
870 	DECLARE_WAITQUEUE(waita, current);
871 	int rc;
872 	int err = 0;
873 
874 	add_wait_queue(&usblp->wwait, &waita);
875 	for (;;) {
876 		set_current_state(TASK_INTERRUPTIBLE);
877 		if (mutex_lock_interruptible(&usblp->mut)) {
878 			rc = -EINTR;
879 			break;
880 		}
881 		rc = usblp_wtest(usblp, nonblock);
882 		mutex_unlock(&usblp->mut);
883 		if (rc <= 0)
884 			break;
885 
886 		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
887 			if (usblp->flags & LP_ABORT) {
888 				err = usblp_check_status(usblp, err);
889 				if (err == 1) {	/* Paper out */
890 					rc = -ENOSPC;
891 					break;
892 				}
893 			} else {
894 				/* Prod the printer, Gentoo#251237. */
895 				mutex_lock(&usblp->mut);
896 				usblp_read_status(usblp, usblp->statusbuf);
897 				mutex_unlock(&usblp->mut);
898 			}
899 		}
900 	}
901 	set_current_state(TASK_RUNNING);
902 	remove_wait_queue(&usblp->wwait, &waita);
903 	return rc;
904 }
905 
906 static int usblp_wtest(struct usblp *usblp, int nonblock)
907 {
908 	unsigned long flags;
909 
910 	if (!usblp->present)
911 		return -ENODEV;
912 	if (signal_pending(current))
913 		return -EINTR;
914 	spin_lock_irqsave(&usblp->lock, flags);
915 	if (usblp->wcomplete) {
916 		spin_unlock_irqrestore(&usblp->lock, flags);
917 		return 0;
918 	}
919 	spin_unlock_irqrestore(&usblp->lock, flags);
920 	if (nonblock)
921 		return -EAGAIN;
922 	return 1;
923 }
924 
925 /*
926  * Wait for read bytes to become available. This probably should have been
927  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
928  * name for functions which lock and return.
929  *
930  * We do not use wait_event_interruptible because it makes locking iffy.
931  */
932 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
933 {
934 	DECLARE_WAITQUEUE(waita, current);
935 	int rc;
936 
937 	add_wait_queue(&usblp->rwait, &waita);
938 	for (;;) {
939 		if (mutex_lock_interruptible(&usblp->mut)) {
940 			rc = -EINTR;
941 			break;
942 		}
943 		set_current_state(TASK_INTERRUPTIBLE);
944 		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
945 			mutex_unlock(&usblp->mut);
946 			break;
947 		}
948 		if (rc == 0)	/* Keep it locked */
949 			break;
950 		mutex_unlock(&usblp->mut);
951 		schedule();
952 	}
953 	set_current_state(TASK_RUNNING);
954 	remove_wait_queue(&usblp->rwait, &waita);
955 	return rc;
956 }
957 
958 static int usblp_rtest(struct usblp *usblp, int nonblock)
959 {
960 	unsigned long flags;
961 
962 	if (!usblp->present)
963 		return -ENODEV;
964 	if (signal_pending(current))
965 		return -EINTR;
966 	spin_lock_irqsave(&usblp->lock, flags);
967 	if (usblp->rcomplete) {
968 		spin_unlock_irqrestore(&usblp->lock, flags);
969 		return 0;
970 	}
971 	spin_unlock_irqrestore(&usblp->lock, flags);
972 	if (nonblock)
973 		return -EAGAIN;
974 	return 1;
975 }
976 
977 /*
978  * Please check ->bidir and other such things outside for now.
979  */
980 static int usblp_submit_read(struct usblp *usblp)
981 {
982 	struct urb *urb;
983 	unsigned long flags;
984 	int rc;
985 
986 	rc = -ENOMEM;
987 	urb = usb_alloc_urb(0, GFP_KERNEL);
988 	if (urb == NULL)
989 		goto raise_urb;
990 
991 	usb_fill_bulk_urb(urb, usblp->dev,
992 		usb_rcvbulkpipe(usblp->dev,
993 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
994 		usblp->readbuf, USBLP_BUF_SIZE_IN,
995 		usblp_bulk_read, usblp);
996 	usb_anchor_urb(urb, &usblp->urbs);
997 
998 	spin_lock_irqsave(&usblp->lock, flags);
999 	usblp->readcount = 0; /* XXX Why here? */
1000 	usblp->rcomplete = 0;
1001 	spin_unlock_irqrestore(&usblp->lock, flags);
1002 	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1003 		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1004 		spin_lock_irqsave(&usblp->lock, flags);
1005 		usblp->rstatus = rc;
1006 		usblp->rcomplete = 1;
1007 		spin_unlock_irqrestore(&usblp->lock, flags);
1008 		goto raise_submit;
1009 	}
1010 
1011 	return 0;
1012 
1013 raise_submit:
1014 	usb_unanchor_urb(urb);
1015 	usb_free_urb(urb);
1016 raise_urb:
1017 	return rc;
1018 }
1019 
1020 /*
1021  * Checks for printers that have quirks, such as requiring unidirectional
1022  * communication but reporting bidirectional; currently some HP printers
1023  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1024  * sent at each open (like some Epsons).
1025  * Returns 1 if found, 0 if not found.
1026  *
1027  * HP recommended that we use the bidirectional interface but
1028  * don't attempt any bulk IN transfers from the IN endpoint.
1029  * Here's some more detail on the problem:
1030  * The problem is not that it isn't bidirectional though. The problem
1031  * is that if you request a device ID, or status information, while
1032  * the buffers are full, the return data will end up in the print data
1033  * buffer. For example if you make sure you never request the device ID
1034  * while you are sending print data, and you don't try to query the
1035  * printer status every couple of milliseconds, you will probably be OK.
1036  */
1037 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1038 {
1039 	int i;
1040 
1041 	for (i = 0; quirk_printers[i].vendorId; i++) {
1042 		if (vendor == quirk_printers[i].vendorId &&
1043 		    product == quirk_printers[i].productId)
1044 			return quirk_printers[i].quirks;
1045 	}
1046 	return 0;
1047 }
1048 
1049 static const struct file_operations usblp_fops = {
1050 	.owner =	THIS_MODULE,
1051 	.read =		usblp_read,
1052 	.write =	usblp_write,
1053 	.poll =		usblp_poll,
1054 	.unlocked_ioctl =	usblp_ioctl,
1055 	.compat_ioctl =		usblp_ioctl,
1056 	.open =		usblp_open,
1057 	.release =	usblp_release,
1058 	.llseek =	noop_llseek,
1059 };
1060 
1061 static char *usblp_devnode(struct device *dev, umode_t *mode)
1062 {
1063 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1064 }
1065 
1066 static struct usb_class_driver usblp_class = {
1067 	.name =		"lp%d",
1068 	.devnode =	usblp_devnode,
1069 	.fops =		&usblp_fops,
1070 	.minor_base =	USBLP_MINOR_BASE,
1071 };
1072 
1073 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1074 {
1075 	struct usb_interface *intf = to_usb_interface(dev);
1076 	struct usblp *usblp = usb_get_intfdata(intf);
1077 
1078 	if (usblp->device_id_string[0] == 0 &&
1079 	    usblp->device_id_string[1] == 0)
1080 		return 0;
1081 
1082 	return sprintf(buf, "%s", usblp->device_id_string+2);
1083 }
1084 
1085 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1086 
1087 static int usblp_probe(struct usb_interface *intf,
1088 		       const struct usb_device_id *id)
1089 {
1090 	struct usb_device *dev = interface_to_usbdev(intf);
1091 	struct usblp *usblp;
1092 	int protocol;
1093 	int retval;
1094 
1095 	/* Malloc and start initializing usblp structure so we can use it
1096 	 * directly. */
1097 	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1098 	if (!usblp) {
1099 		retval = -ENOMEM;
1100 		goto abort_ret;
1101 	}
1102 	usblp->dev = dev;
1103 	mutex_init(&usblp->wmut);
1104 	mutex_init(&usblp->mut);
1105 	spin_lock_init(&usblp->lock);
1106 	init_waitqueue_head(&usblp->rwait);
1107 	init_waitqueue_head(&usblp->wwait);
1108 	init_usb_anchor(&usblp->urbs);
1109 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1110 	usblp->intf = intf;
1111 
1112 	/* Malloc device ID string buffer to the largest expected length,
1113 	 * since we can re-query it on an ioctl and a dynamic string
1114 	 * could change in length. */
1115 	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1116 		retval = -ENOMEM;
1117 		goto abort;
1118 	}
1119 
1120 	/*
1121 	 * Allocate read buffer. We somewhat wastefully
1122 	 * malloc both regardless of bidirectionality, because the
1123 	 * alternate setting can be changed later via an ioctl.
1124 	 */
1125 	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1126 		retval = -ENOMEM;
1127 		goto abort;
1128 	}
1129 
1130 	/* Allocate buffer for printer status */
1131 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1132 	if (!usblp->statusbuf) {
1133 		retval = -ENOMEM;
1134 		goto abort;
1135 	}
1136 
1137 	/* Lookup quirks for this printer. */
1138 	usblp->quirks = usblp_quirks(
1139 		le16_to_cpu(dev->descriptor.idVendor),
1140 		le16_to_cpu(dev->descriptor.idProduct));
1141 
1142 	/* Analyze and pick initial alternate settings and endpoints. */
1143 	protocol = usblp_select_alts(usblp);
1144 	if (protocol < 0) {
1145 		dev_dbg(&intf->dev,
1146 			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1147 			le16_to_cpu(dev->descriptor.idVendor),
1148 			le16_to_cpu(dev->descriptor.idProduct));
1149 		retval = -ENODEV;
1150 		goto abort;
1151 	}
1152 
1153 	/* Setup the selected alternate setting and endpoints. */
1154 	if (usblp_set_protocol(usblp, protocol) < 0) {
1155 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1156 		goto abort;
1157 	}
1158 
1159 	/* Retrieve and store the device ID string. */
1160 	usblp_cache_device_id_string(usblp);
1161 	retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1162 	if (retval)
1163 		goto abort_intfdata;
1164 
1165 #ifdef DEBUG
1166 	usblp_check_status(usblp, 0);
1167 #endif
1168 
1169 	usb_set_intfdata(intf, usblp);
1170 
1171 	usblp->present = 1;
1172 
1173 	retval = usb_register_dev(intf, &usblp_class);
1174 	if (retval) {
1175 		dev_err(&intf->dev,
1176 			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1177 			USBLP_MINOR_BASE, retval);
1178 		goto abort_intfdata;
1179 	}
1180 	usblp->minor = intf->minor;
1181 	dev_info(&intf->dev,
1182 		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1183 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1184 		usblp->ifnum,
1185 		usblp->protocol[usblp->current_protocol].alt_setting,
1186 		usblp->current_protocol,
1187 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1188 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1189 
1190 	return 0;
1191 
1192 abort_intfdata:
1193 	usb_set_intfdata(intf, NULL);
1194 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1195 abort:
1196 	kfree(usblp->readbuf);
1197 	kfree(usblp->statusbuf);
1198 	kfree(usblp->device_id_string);
1199 	kfree(usblp);
1200 abort_ret:
1201 	return retval;
1202 }
1203 
1204 /*
1205  * We are a "new" style driver with usb_device_id table,
1206  * but our requirements are too intricate for simple match to handle.
1207  *
1208  * The "proto_bias" option may be used to specify the preferred protocol
1209  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1210  * supports the preferred protocol, then we bind to it.
1211  *
1212  * The best interface for us is 7/1/2, because it is compatible
1213  * with a stream of characters. If we find it, we bind to it.
1214  *
1215  * Note that the people from hpoj.sourceforge.net need to be able to
1216  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1217  *
1218  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1219  * stream-compatible, because this matches the behaviour of the old code.
1220  *
1221  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1222  */
1223 static int usblp_select_alts(struct usblp *usblp)
1224 {
1225 	struct usb_interface *if_alt;
1226 	struct usb_host_interface *ifd;
1227 	struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1228 	int p, i, e;
1229 
1230 	if_alt = usblp->intf;
1231 
1232 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1233 		usblp->protocol[p].alt_setting = -1;
1234 
1235 	/* Find out what we have. */
1236 	for (i = 0; i < if_alt->num_altsetting; i++) {
1237 		ifd = &if_alt->altsetting[i];
1238 
1239 		if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1240 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1241 				continue;
1242 
1243 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1244 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1245 			continue;
1246 
1247 		/* Look for bulk OUT and IN endpoints. */
1248 		epwrite = epread = NULL;
1249 		for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1250 			epd = &ifd->endpoint[e].desc;
1251 
1252 			if (usb_endpoint_is_bulk_out(epd))
1253 				if (!epwrite)
1254 					epwrite = epd;
1255 
1256 			if (usb_endpoint_is_bulk_in(epd))
1257 				if (!epread)
1258 					epread = epd;
1259 		}
1260 
1261 		/* Ignore buggy hardware without the right endpoints. */
1262 		if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1263 			continue;
1264 
1265 		/* Turn off reads for 7/1/1 (unidirectional) interfaces
1266 		 * and buggy bidirectional printers. */
1267 		if (ifd->desc.bInterfaceProtocol == 1) {
1268 			epread = NULL;
1269 		} else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1270 			printk(KERN_INFO "usblp%d: Disabling reads from "
1271 			    "problematic bidirectional printer\n",
1272 			    usblp->minor);
1273 			epread = NULL;
1274 		}
1275 
1276 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1277 				ifd->desc.bAlternateSetting;
1278 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1279 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1280 	}
1281 
1282 	/* If our requested protocol is supported, then use it. */
1283 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1284 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1285 	    usblp->protocol[proto_bias].alt_setting != -1)
1286 		return proto_bias;
1287 
1288 	/* Ordering is important here. */
1289 	if (usblp->protocol[2].alt_setting != -1)
1290 		return 2;
1291 	if (usblp->protocol[1].alt_setting != -1)
1292 		return 1;
1293 	if (usblp->protocol[3].alt_setting != -1)
1294 		return 3;
1295 
1296 	/* If nothing is available, then don't bind to this device. */
1297 	return -1;
1298 }
1299 
1300 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1301 {
1302 	int r, alts;
1303 
1304 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1305 		return -EINVAL;
1306 
1307 	alts = usblp->protocol[protocol].alt_setting;
1308 	if (alts < 0)
1309 		return -EINVAL;
1310 	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1311 	if (r < 0) {
1312 		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1313 			alts, usblp->ifnum);
1314 		return r;
1315 	}
1316 
1317 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1318 	usblp->current_protocol = protocol;
1319 	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1320 		usblp->minor, protocol);
1321 	return 0;
1322 }
1323 
1324 /* Retrieves and caches device ID string.
1325  * Returns length, including length bytes but not null terminator.
1326  * On error, returns a negative errno value. */
1327 static int usblp_cache_device_id_string(struct usblp *usblp)
1328 {
1329 	int err, length;
1330 
1331 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1332 	if (err < 0) {
1333 		dev_dbg(&usblp->intf->dev,
1334 			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1335 			usblp->minor, err);
1336 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1337 		return -EIO;
1338 	}
1339 
1340 	/* First two bytes are length in big-endian.
1341 	 * They count themselves, and we copy them into
1342 	 * the user's buffer. */
1343 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1344 	if (length < 2)
1345 		length = 2;
1346 	else if (length >= USBLP_DEVICE_ID_SIZE)
1347 		length = USBLP_DEVICE_ID_SIZE - 1;
1348 	usblp->device_id_string[length] = '\0';
1349 
1350 	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1351 		usblp->minor, length, &usblp->device_id_string[2]);
1352 
1353 	return length;
1354 }
1355 
1356 static void usblp_disconnect(struct usb_interface *intf)
1357 {
1358 	struct usblp *usblp = usb_get_intfdata(intf);
1359 
1360 	usb_deregister_dev(intf, &usblp_class);
1361 
1362 	if (!usblp || !usblp->dev) {
1363 		dev_err(&intf->dev, "bogus disconnect\n");
1364 		BUG();
1365 	}
1366 
1367 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
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 
1384 static 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 
1398 static 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 
1408 static const struct usb_device_id usblp_ids[] = {
1409 	{ USB_DEVICE_INFO(7, 1, 1) },
1410 	{ USB_DEVICE_INFO(7, 1, 2) },
1411 	{ USB_DEVICE_INFO(7, 1, 3) },
1412 	{ USB_INTERFACE_INFO(7, 1, 1) },
1413 	{ USB_INTERFACE_INFO(7, 1, 2) },
1414 	{ USB_INTERFACE_INFO(7, 1, 3) },
1415 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1416 	{ }						/* Terminating entry */
1417 };
1418 
1419 MODULE_DEVICE_TABLE(usb, usblp_ids);
1420 
1421 static 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 	.supports_autosuspend =	1,
1429 };
1430 
1431 module_usb_driver(usblp_driver);
1432 
1433 MODULE_AUTHOR(DRIVER_AUTHOR);
1434 MODULE_DESCRIPTION(DRIVER_DESC);
1435 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1436 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1437 MODULE_LICENSE("GPL");
1438