xref: /openbmc/linux/drivers/usb/class/usblp.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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/init.h>
56 #include <linux/slab.h>
57 #include <linux/lp.h>
58 #include <linux/mutex.h>
59 #undef DEBUG
60 #include <linux/usb.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 	int p;
175 
176 	dbg("usblp=0x%p", usblp);
177 	dbg("dev=0x%p", usblp->dev);
178 	dbg("present=%d", usblp->present);
179 	dbg("readbuf=0x%p", usblp->readbuf);
180 	dbg("readcount=%d", usblp->readcount);
181 	dbg("ifnum=%d", usblp->ifnum);
182     for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
183 	dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
184 	dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
185 	dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
186     }
187 	dbg("current_protocol=%d", usblp->current_protocol);
188 	dbg("minor=%d", usblp->minor);
189 	dbg("wstatus=%d", usblp->wstatus);
190 	dbg("rstatus=%d", usblp->rstatus);
191 	dbg("quirks=%d", usblp->quirks);
192 	dbg("used=%d", usblp->used);
193 	dbg("bidir=%d", usblp->bidir);
194 	dbg("device_id_string=\"%s\"",
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 
203 struct 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 
213 static 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 
233 static int usblp_wwait(struct usblp *usblp, int nonblock);
234 static int usblp_wtest(struct usblp *usblp, int nonblock);
235 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
236 static int usblp_rtest(struct usblp *usblp, int nonblock);
237 static int usblp_submit_read(struct usblp *usblp);
238 static int usblp_select_alts(struct usblp *usblp);
239 static int usblp_set_protocol(struct usblp *usblp, int protocol);
240 static int usblp_cache_device_id_string(struct usblp *usblp);
241 
242 /* forward reference to make our lives easier */
243 static struct usb_driver usblp_driver;
244 static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
245 
246 /*
247  * Functions for usblp control messages.
248  */
249 
250 static 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 	dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
265 		request, !!dir, recip, value, index, len, retval);
266 	return retval < 0 ? retval : 0;
267 }
268 
269 #define usblp_read_status(usblp, status)\
270 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
271 #define usblp_get_id(usblp, config, id, maxlen)\
272 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
273 #define usblp_reset(usblp)\
274 	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
275 
276 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
277 	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
278 
279 /*
280  * See the description for usblp_select_alts() below for the usage
281  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
282  * case of any trouble.
283  */
284 static int proto_bias = -1;
285 
286 /*
287  * URB callback.
288  */
289 
290 static void usblp_bulk_read(struct urb *urb)
291 {
292 	struct usblp *usblp = urb->context;
293 	int status = urb->status;
294 
295 	if (usblp->present && usblp->used) {
296 		if (status)
297 			printk(KERN_WARNING "usblp%d: "
298 			    "nonzero read bulk status received: %d\n",
299 			    usblp->minor, status);
300 	}
301 	spin_lock(&usblp->lock);
302 	if (status < 0)
303 		usblp->rstatus = status;
304 	else
305 		usblp->rstatus = urb->actual_length;
306 	usblp->rcomplete = 1;
307 	wake_up(&usblp->rwait);
308 	spin_unlock(&usblp->lock);
309 
310 	usb_free_urb(urb);
311 }
312 
313 static void usblp_bulk_write(struct urb *urb)
314 {
315 	struct usblp *usblp = urb->context;
316 	int status = urb->status;
317 
318 	if (usblp->present && usblp->used) {
319 		if (status)
320 			printk(KERN_WARNING "usblp%d: "
321 			    "nonzero write bulk status received: %d\n",
322 			    usblp->minor, status);
323 	}
324 	spin_lock(&usblp->lock);
325 	if (status < 0)
326 		usblp->wstatus = status;
327 	else
328 		usblp->wstatus = urb->actual_length;
329 	usblp->no_paper = 0;
330 	usblp->wcomplete = 1;
331 	wake_up(&usblp->wwait);
332 	spin_unlock(&usblp->lock);
333 
334 	usb_free_urb(urb);
335 }
336 
337 /*
338  * Get and print printer errors.
339  */
340 
341 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
342 
343 static int usblp_check_status(struct usblp *usblp, int err)
344 {
345 	unsigned char status, newerr = 0;
346 	int error;
347 
348 	mutex_lock(&usblp->mut);
349 	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
350 		mutex_unlock(&usblp->mut);
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 	status = *usblp->statusbuf;
358 	mutex_unlock(&usblp->mut);
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) {
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 	usblp = usb_get_intfdata(intf);
405 	if (!usblp || !usblp->dev || !usblp->present)
406 		goto out;
407 
408 	retval = -EBUSY;
409 	if (usblp->used)
410 		goto out;
411 
412 	/*
413 	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
414 	 *  - We do not want persistent state which close(2) does not clear
415 	 *  - It is not used anyway, according to CUPS people
416 	 */
417 
418 	retval = usb_autopm_get_interface(intf);
419 	if (retval < 0)
420 		goto out;
421 	usblp->used = 1;
422 	file->private_data = usblp;
423 
424 	usblp->wcomplete = 1; /* we begin writeable */
425 	usblp->wstatus = 0;
426 	usblp->rcomplete = 0;
427 
428 	if (handle_bidir(usblp) < 0) {
429 		usb_autopm_put_interface(intf);
430 		usblp->used = 0;
431 		file->private_data = NULL;
432 		retval = -EIO;
433 	}
434 out:
435 	mutex_unlock(&usblp_mutex);
436 	return retval;
437 }
438 
439 static void usblp_cleanup(struct usblp *usblp)
440 {
441 	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
442 
443 	kfree(usblp->readbuf);
444 	kfree(usblp->device_id_string);
445 	kfree(usblp->statusbuf);
446 	kfree(usblp);
447 }
448 
449 static void usblp_unlink_urbs(struct usblp *usblp)
450 {
451 	usb_kill_anchored_urbs(&usblp->urbs);
452 }
453 
454 static int usblp_release(struct inode *inode, struct file *file)
455 {
456 	struct usblp *usblp = file->private_data;
457 
458 	usblp->flags &= ~LP_ABORT;
459 
460 	mutex_lock(&usblp_mutex);
461 	usblp->used = 0;
462 	if (usblp->present) {
463 		usblp_unlink_urbs(usblp);
464 		usb_autopm_put_interface(usblp->intf);
465 	} else		/* finish cleanup from disconnect */
466 		usblp_cleanup(usblp);
467 	mutex_unlock(&usblp_mutex);
468 	return 0;
469 }
470 
471 /* No kernel lock - fine */
472 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
473 {
474 	int ret;
475 	unsigned long flags;
476 
477 	struct usblp *usblp = file->private_data;
478 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
479 	poll_wait(file, &usblp->rwait, wait);
480 	poll_wait(file, &usblp->wwait, wait);
481 	spin_lock_irqsave(&usblp->lock, flags);
482 	ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
483 	   ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
484 	spin_unlock_irqrestore(&usblp->lock, flags);
485 	return ret;
486 }
487 
488 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
489 {
490 	struct usblp *usblp = file->private_data;
491 	int length, err, i;
492 	unsigned char newChannel;
493 	int status;
494 	int twoints[2];
495 	int retval = 0;
496 
497 	mutex_lock(&usblp->mut);
498 	if (!usblp->present) {
499 		retval = -ENODEV;
500 		goto done;
501 	}
502 
503 	dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
504 		_IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
505 
506 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
507 
508 		switch (_IOC_NR(cmd)) {
509 
510 		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
511 			if (_IOC_DIR(cmd) != _IOC_READ) {
512 				retval = -EINVAL;
513 				goto done;
514 			}
515 
516 			length = usblp_cache_device_id_string(usblp);
517 			if (length < 0) {
518 				retval = length;
519 				goto done;
520 			}
521 			if (length > _IOC_SIZE(cmd))
522 				length = _IOC_SIZE(cmd); /* truncate */
523 
524 			if (copy_to_user((void __user *) arg,
525 					usblp->device_id_string,
526 					(unsigned long) length)) {
527 				retval = -EFAULT;
528 				goto done;
529 			}
530 
531 			break;
532 
533 		case IOCNR_GET_PROTOCOLS:
534 			if (_IOC_DIR(cmd) != _IOC_READ ||
535 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
536 				retval = -EINVAL;
537 				goto done;
538 			}
539 
540 			twoints[0] = usblp->current_protocol;
541 			twoints[1] = 0;
542 			for (i = USBLP_FIRST_PROTOCOL;
543 			     i <= USBLP_LAST_PROTOCOL; i++) {
544 				if (usblp->protocol[i].alt_setting >= 0)
545 					twoints[1] |= (1<<i);
546 			}
547 
548 			if (copy_to_user((void __user *)arg,
549 					(unsigned char *)twoints,
550 					sizeof(twoints))) {
551 				retval = -EFAULT;
552 				goto done;
553 			}
554 
555 			break;
556 
557 		case IOCNR_SET_PROTOCOL:
558 			if (_IOC_DIR(cmd) != _IOC_WRITE) {
559 				retval = -EINVAL;
560 				goto done;
561 			}
562 
563 #ifdef DEBUG
564 			if (arg == -10) {
565 				usblp_dump(usblp);
566 				break;
567 			}
568 #endif
569 
570 			usblp_unlink_urbs(usblp);
571 			retval = usblp_set_protocol(usblp, arg);
572 			if (retval < 0) {
573 				usblp_set_protocol(usblp,
574 					usblp->current_protocol);
575 			}
576 			break;
577 
578 		case IOCNR_HP_SET_CHANNEL:
579 			if (_IOC_DIR(cmd) != _IOC_WRITE ||
580 			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
581 			    usblp->quirks & USBLP_QUIRK_BIDIR) {
582 				retval = -EINVAL;
583 				goto done;
584 			}
585 
586 			err = usblp_hp_channel_change_request(usblp,
587 				arg, &newChannel);
588 			if (err < 0) {
589 				dev_err(&usblp->dev->dev,
590 					"usblp%d: error = %d setting "
591 					"HP channel\n",
592 					usblp->minor, err);
593 				retval = -EIO;
594 				goto done;
595 			}
596 
597 			dbg("usblp%d requested/got HP channel %ld/%d",
598 				usblp->minor, arg, newChannel);
599 			break;
600 
601 		case IOCNR_GET_BUS_ADDRESS:
602 			if (_IOC_DIR(cmd) != _IOC_READ ||
603 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
604 				retval = -EINVAL;
605 				goto done;
606 			}
607 
608 			twoints[0] = usblp->dev->bus->busnum;
609 			twoints[1] = usblp->dev->devnum;
610 			if (copy_to_user((void __user *)arg,
611 					(unsigned char *)twoints,
612 					sizeof(twoints))) {
613 				retval = -EFAULT;
614 				goto done;
615 			}
616 
617 			dbg("usblp%d is bus=%d, device=%d",
618 				usblp->minor, twoints[0], twoints[1]);
619 			break;
620 
621 		case IOCNR_GET_VID_PID:
622 			if (_IOC_DIR(cmd) != _IOC_READ ||
623 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
624 				retval = -EINVAL;
625 				goto done;
626 			}
627 
628 			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
629 			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
630 			if (copy_to_user((void __user *)arg,
631 					(unsigned char *)twoints,
632 					sizeof(twoints))) {
633 				retval = -EFAULT;
634 				goto done;
635 			}
636 
637 			dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
638 				usblp->minor, twoints[0], twoints[1]);
639 			break;
640 
641 		case IOCNR_SOFT_RESET:
642 			if (_IOC_DIR(cmd) != _IOC_NONE) {
643 				retval = -EINVAL;
644 				goto done;
645 			}
646 			retval = usblp_reset(usblp);
647 			break;
648 		default:
649 			retval = -ENOTTY;
650 		}
651 	else	/* old-style ioctl value */
652 		switch (cmd) {
653 
654 		case LPGETSTATUS:
655 			if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
656 				if (printk_ratelimit())
657 					printk(KERN_ERR "usblp%d:"
658 					    "failed reading printer status (%d)\n",
659 					    usblp->minor, retval);
660 				retval = -EIO;
661 				goto done;
662 			}
663 			status = *usblp->statusbuf;
664 			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
665 				retval = -EFAULT;
666 			break;
667 
668 		case LPABORT:
669 			if (arg)
670 				usblp->flags |= LP_ABORT;
671 			else
672 				usblp->flags &= ~LP_ABORT;
673 			break;
674 
675 		default:
676 			retval = -ENOTTY;
677 		}
678 
679 done:
680 	mutex_unlock(&usblp->mut);
681 	return retval;
682 }
683 
684 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
685 {
686 	struct urb *urb;
687 	char *writebuf;
688 
689 	if ((writebuf = kmalloc(transfer_length, GFP_KERNEL)) == NULL)
690 		return NULL;
691 	if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL) {
692 		kfree(writebuf);
693 		return NULL;
694 	}
695 
696 	usb_fill_bulk_urb(urb, usblp->dev,
697 		usb_sndbulkpipe(usblp->dev,
698 		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
699 		writebuf, transfer_length, usblp_bulk_write, usblp);
700 	urb->transfer_flags |= URB_FREE_BUFFER;
701 
702 	return urb;
703 }
704 
705 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
706 {
707 	struct usblp *usblp = file->private_data;
708 	struct urb *writeurb;
709 	int rv;
710 	int transfer_length;
711 	ssize_t writecount = 0;
712 
713 	if (mutex_lock_interruptible(&usblp->wmut)) {
714 		rv = -EINTR;
715 		goto raise_biglock;
716 	}
717 	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
718 		goto raise_wait;
719 
720 	while (writecount < count) {
721 		/*
722 		 * Step 1: Submit next block.
723 		 */
724 		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
725 			transfer_length = USBLP_BUF_SIZE;
726 
727 		rv = -ENOMEM;
728 		if ((writeurb = usblp_new_writeurb(usblp, transfer_length)) == NULL)
729 			goto raise_urb;
730 		usb_anchor_urb(writeurb, &usblp->urbs);
731 
732 		if (copy_from_user(writeurb->transfer_buffer,
733 				   buffer + writecount, transfer_length)) {
734 			rv = -EFAULT;
735 			goto raise_badaddr;
736 		}
737 
738 		spin_lock_irq(&usblp->lock);
739 		usblp->wcomplete = 0;
740 		spin_unlock_irq(&usblp->lock);
741 		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
742 			usblp->wstatus = 0;
743 			spin_lock_irq(&usblp->lock);
744 			usblp->no_paper = 0;
745 			usblp->wcomplete = 1;
746 			wake_up(&usblp->wwait);
747 			spin_unlock_irq(&usblp->lock);
748 			if (rv != -ENOMEM)
749 				rv = -EIO;
750 			goto raise_submit;
751 		}
752 
753 		/*
754 		 * Step 2: Wait for transfer to end, collect results.
755 		 */
756 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
757 		if (rv < 0) {
758 			if (rv == -EAGAIN) {
759 				/* Presume that it's going to complete well. */
760 				writecount += transfer_length;
761 			}
762 			if (rv == -ENOSPC) {
763 				spin_lock_irq(&usblp->lock);
764 				usblp->no_paper = 1;	/* Mark for poll(2) */
765 				spin_unlock_irq(&usblp->lock);
766 				writecount += transfer_length;
767 			}
768 			/* Leave URB dangling, to be cleaned on close. */
769 			goto collect_error;
770 		}
771 
772 		if (usblp->wstatus < 0) {
773 			rv = -EIO;
774 			goto collect_error;
775 		}
776 		/*
777 		 * This is critical: it must be our URB, not other writer's.
778 		 * The wmut exists mainly to cover us here.
779 		 */
780 		writecount += usblp->wstatus;
781 	}
782 
783 	mutex_unlock(&usblp->wmut);
784 	return writecount;
785 
786 raise_submit:
787 raise_badaddr:
788 	usb_unanchor_urb(writeurb);
789 	usb_free_urb(writeurb);
790 raise_urb:
791 raise_wait:
792 collect_error:		/* Out of raise sequence */
793 	mutex_unlock(&usblp->wmut);
794 raise_biglock:
795 	return writecount ? writecount : rv;
796 }
797 
798 /*
799  * Notice that we fail to restart in a few cases: on EFAULT, on restart
800  * error, etc. This is the historical behaviour. In all such cases we return
801  * EIO, and applications loop in order to get the new read going.
802  */
803 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
804 {
805 	struct usblp *usblp = file->private_data;
806 	ssize_t count;
807 	ssize_t avail;
808 	int rv;
809 
810 	if (!usblp->bidir)
811 		return -EINVAL;
812 
813 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
814 	if (rv < 0)
815 		return rv;
816 
817 	if ((avail = usblp->rstatus) < 0) {
818 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
819 		    usblp->minor, (int)avail);
820 		usblp_submit_read(usblp);
821 		count = -EIO;
822 		goto done;
823 	}
824 
825 	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
826 	if (count != 0 &&
827 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
828 		count = -EFAULT;
829 		goto done;
830 	}
831 
832 	if ((usblp->readcount += count) == avail) {
833 		if (usblp_submit_read(usblp) < 0) {
834 			/* We don't want to leak USB return codes into errno. */
835 			if (count == 0)
836 				count = -EIO;
837 			goto done;
838 		}
839 	}
840 
841 done:
842 	mutex_unlock(&usblp->mut);
843 	return count;
844 }
845 
846 /*
847  * Wait for the write path to come idle.
848  * This is called under the ->wmut, so the idle path stays idle.
849  *
850  * Our write path has a peculiar property: it does not buffer like a tty,
851  * but waits for the write to succeed. This allows our ->release to bug out
852  * without waiting for writes to drain. But it obviously does not work
853  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
854  * select(2) or poll(2) to wait for the buffer to drain before closing.
855  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
856  */
857 static int usblp_wwait(struct usblp *usblp, int nonblock)
858 {
859 	DECLARE_WAITQUEUE(waita, current);
860 	int rc;
861 	int err = 0;
862 
863 	add_wait_queue(&usblp->wwait, &waita);
864 	for (;;) {
865 		set_current_state(TASK_INTERRUPTIBLE);
866 		if (mutex_lock_interruptible(&usblp->mut)) {
867 			rc = -EINTR;
868 			break;
869 		}
870 		rc = usblp_wtest(usblp, nonblock);
871 		mutex_unlock(&usblp->mut);
872 		if (rc <= 0)
873 			break;
874 
875 		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
876 			if (usblp->flags & LP_ABORT) {
877 				err = usblp_check_status(usblp, err);
878 				if (err == 1) {	/* Paper out */
879 					rc = -ENOSPC;
880 					break;
881 				}
882 			} else {
883 				/* Prod the printer, Gentoo#251237. */
884 				mutex_lock(&usblp->mut);
885 				usblp_read_status(usblp, usblp->statusbuf);
886 				mutex_unlock(&usblp->mut);
887 			}
888 		}
889 	}
890 	set_current_state(TASK_RUNNING);
891 	remove_wait_queue(&usblp->wwait, &waita);
892 	return rc;
893 }
894 
895 static int usblp_wtest(struct usblp *usblp, int nonblock)
896 {
897 	unsigned long flags;
898 
899 	if (!usblp->present)
900 		return -ENODEV;
901 	if (signal_pending(current))
902 		return -EINTR;
903 	spin_lock_irqsave(&usblp->lock, flags);
904 	if (usblp->wcomplete) {
905 		spin_unlock_irqrestore(&usblp->lock, flags);
906 		return 0;
907 	}
908 	spin_unlock_irqrestore(&usblp->lock, flags);
909 	if (nonblock)
910 		return -EAGAIN;
911 	return 1;
912 }
913 
914 /*
915  * Wait for read bytes to become available. This probably should have been
916  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
917  * name for functions which lock and return.
918  *
919  * We do not use wait_event_interruptible because it makes locking iffy.
920  */
921 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
922 {
923 	DECLARE_WAITQUEUE(waita, current);
924 	int rc;
925 
926 	add_wait_queue(&usblp->rwait, &waita);
927 	for (;;) {
928 		if (mutex_lock_interruptible(&usblp->mut)) {
929 			rc = -EINTR;
930 			break;
931 		}
932 		set_current_state(TASK_INTERRUPTIBLE);
933 		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
934 			mutex_unlock(&usblp->mut);
935 			break;
936 		}
937 		if (rc == 0)	/* Keep it locked */
938 			break;
939 		mutex_unlock(&usblp->mut);
940 		schedule();
941 	}
942 	set_current_state(TASK_RUNNING);
943 	remove_wait_queue(&usblp->rwait, &waita);
944 	return rc;
945 }
946 
947 static int usblp_rtest(struct usblp *usblp, int nonblock)
948 {
949 	unsigned long flags;
950 
951 	if (!usblp->present)
952 		return -ENODEV;
953 	if (signal_pending(current))
954 		return -EINTR;
955 	spin_lock_irqsave(&usblp->lock, flags);
956 	if (usblp->rcomplete) {
957 		spin_unlock_irqrestore(&usblp->lock, flags);
958 		return 0;
959 	}
960 	spin_unlock_irqrestore(&usblp->lock, flags);
961 	if (nonblock)
962 		return -EAGAIN;
963 	return 1;
964 }
965 
966 /*
967  * Please check ->bidir and other such things outside for now.
968  */
969 static int usblp_submit_read(struct usblp *usblp)
970 {
971 	struct urb *urb;
972 	unsigned long flags;
973 	int rc;
974 
975 	rc = -ENOMEM;
976 	if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
977 		goto raise_urb;
978 
979 	usb_fill_bulk_urb(urb, usblp->dev,
980 		usb_rcvbulkpipe(usblp->dev,
981 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
982 		usblp->readbuf, USBLP_BUF_SIZE_IN,
983 		usblp_bulk_read, usblp);
984 	usb_anchor_urb(urb, &usblp->urbs);
985 
986 	spin_lock_irqsave(&usblp->lock, flags);
987 	usblp->readcount = 0; /* XXX Why here? */
988 	usblp->rcomplete = 0;
989 	spin_unlock_irqrestore(&usblp->lock, flags);
990 	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
991 		dbg("error submitting urb (%d)", rc);
992 		spin_lock_irqsave(&usblp->lock, flags);
993 		usblp->rstatus = rc;
994 		usblp->rcomplete = 1;
995 		spin_unlock_irqrestore(&usblp->lock, flags);
996 		goto raise_submit;
997 	}
998 
999 	return 0;
1000 
1001 raise_submit:
1002 	usb_unanchor_urb(urb);
1003 	usb_free_urb(urb);
1004 raise_urb:
1005 	return rc;
1006 }
1007 
1008 /*
1009  * Checks for printers that have quirks, such as requiring unidirectional
1010  * communication but reporting bidirectional; currently some HP printers
1011  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1012  * sent at each open (like some Epsons).
1013  * Returns 1 if found, 0 if not found.
1014  *
1015  * HP recommended that we use the bidirectional interface but
1016  * don't attempt any bulk IN transfers from the IN endpoint.
1017  * Here's some more detail on the problem:
1018  * The problem is not that it isn't bidirectional though. The problem
1019  * is that if you request a device ID, or status information, while
1020  * the buffers are full, the return data will end up in the print data
1021  * buffer. For example if you make sure you never request the device ID
1022  * while you are sending print data, and you don't try to query the
1023  * printer status every couple of milliseconds, you will probably be OK.
1024  */
1025 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1026 {
1027 	int i;
1028 
1029 	for (i = 0; quirk_printers[i].vendorId; i++) {
1030 		if (vendor == quirk_printers[i].vendorId &&
1031 		    product == quirk_printers[i].productId)
1032 			return quirk_printers[i].quirks;
1033 	}
1034 	return 0;
1035 }
1036 
1037 static const struct file_operations usblp_fops = {
1038 	.owner =	THIS_MODULE,
1039 	.read =		usblp_read,
1040 	.write =	usblp_write,
1041 	.poll =		usblp_poll,
1042 	.unlocked_ioctl =	usblp_ioctl,
1043 	.compat_ioctl =		usblp_ioctl,
1044 	.open =		usblp_open,
1045 	.release =	usblp_release,
1046 	.llseek =	noop_llseek,
1047 };
1048 
1049 static char *usblp_devnode(struct device *dev, mode_t *mode)
1050 {
1051 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1052 }
1053 
1054 static struct usb_class_driver usblp_class = {
1055 	.name =		"lp%d",
1056 	.devnode =	usblp_devnode,
1057 	.fops =		&usblp_fops,
1058 	.minor_base =	USBLP_MINOR_BASE,
1059 };
1060 
1061 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1062 {
1063 	struct usb_interface *intf = to_usb_interface(dev);
1064 	struct usblp *usblp = usb_get_intfdata(intf);
1065 
1066 	if (usblp->device_id_string[0] == 0 &&
1067 	    usblp->device_id_string[1] == 0)
1068 		return 0;
1069 
1070 	return sprintf(buf, "%s", usblp->device_id_string+2);
1071 }
1072 
1073 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1074 
1075 static int usblp_probe(struct usb_interface *intf,
1076 		       const struct usb_device_id *id)
1077 {
1078 	struct usb_device *dev = interface_to_usbdev(intf);
1079 	struct usblp *usblp;
1080 	int protocol;
1081 	int retval;
1082 
1083 	/* Malloc and start initializing usblp structure so we can use it
1084 	 * directly. */
1085 	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1086 	if (!usblp) {
1087 		retval = -ENOMEM;
1088 		goto abort_ret;
1089 	}
1090 	usblp->dev = dev;
1091 	mutex_init(&usblp->wmut);
1092 	mutex_init(&usblp->mut);
1093 	spin_lock_init(&usblp->lock);
1094 	init_waitqueue_head(&usblp->rwait);
1095 	init_waitqueue_head(&usblp->wwait);
1096 	init_usb_anchor(&usblp->urbs);
1097 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1098 	usblp->intf = intf;
1099 
1100 	/* Malloc device ID string buffer to the largest expected length,
1101 	 * since we can re-query it on an ioctl and a dynamic string
1102 	 * could change in length. */
1103 	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1104 		retval = -ENOMEM;
1105 		goto abort;
1106 	}
1107 
1108 	/*
1109 	 * Allocate read buffer. We somewhat wastefully
1110 	 * malloc both regardless of bidirectionality, because the
1111 	 * alternate setting can be changed later via an ioctl.
1112 	 */
1113 	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1114 		retval = -ENOMEM;
1115 		goto abort;
1116 	}
1117 
1118 	/* Allocate buffer for printer status */
1119 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1120 	if (!usblp->statusbuf) {
1121 		retval = -ENOMEM;
1122 		goto abort;
1123 	}
1124 
1125 	/* Lookup quirks for this printer. */
1126 	usblp->quirks = usblp_quirks(
1127 		le16_to_cpu(dev->descriptor.idVendor),
1128 		le16_to_cpu(dev->descriptor.idProduct));
1129 
1130 	/* Analyze and pick initial alternate settings and endpoints. */
1131 	protocol = usblp_select_alts(usblp);
1132 	if (protocol < 0) {
1133 		dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
1134 			le16_to_cpu(dev->descriptor.idVendor),
1135 			le16_to_cpu(dev->descriptor.idProduct));
1136 		retval = -ENODEV;
1137 		goto abort;
1138 	}
1139 
1140 	/* Setup the selected alternate setting and endpoints. */
1141 	if (usblp_set_protocol(usblp, protocol) < 0) {
1142 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1143 		goto abort;
1144 	}
1145 
1146 	/* Retrieve and store the device ID string. */
1147 	usblp_cache_device_id_string(usblp);
1148 	retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1149 	if (retval)
1150 		goto abort_intfdata;
1151 
1152 #ifdef DEBUG
1153 	usblp_check_status(usblp, 0);
1154 #endif
1155 
1156 	usb_set_intfdata(intf, usblp);
1157 
1158 	usblp->present = 1;
1159 
1160 	retval = usb_register_dev(intf, &usblp_class);
1161 	if (retval) {
1162 		printk(KERN_ERR "usblp: Not able to get a minor"
1163 		    " (base %u, slice default): %d\n",
1164 		    USBLP_MINOR_BASE, retval);
1165 		goto abort_intfdata;
1166 	}
1167 	usblp->minor = intf->minor;
1168 	printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
1169 		"if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1170 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1171 		usblp->ifnum,
1172 		usblp->protocol[usblp->current_protocol].alt_setting,
1173 		usblp->current_protocol,
1174 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1175 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1176 
1177 	return 0;
1178 
1179 abort_intfdata:
1180 	usb_set_intfdata(intf, NULL);
1181 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1182 abort:
1183 	kfree(usblp->readbuf);
1184 	kfree(usblp->statusbuf);
1185 	kfree(usblp->device_id_string);
1186 	kfree(usblp);
1187 abort_ret:
1188 	return retval;
1189 }
1190 
1191 /*
1192  * We are a "new" style driver with usb_device_id table,
1193  * but our requirements are too intricate for simple match to handle.
1194  *
1195  * The "proto_bias" option may be used to specify the preferred protocol
1196  * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
1197  * supports the preferred protocol, then we bind to it.
1198  *
1199  * The best interface for us is 7/1/2, because it is compatible
1200  * with a stream of characters. If we find it, we bind to it.
1201  *
1202  * Note that the people from hpoj.sourceforge.net need to be able to
1203  * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
1204  *
1205  * Failing 7/1/2, we look for 7/1/3, even though it's probably not
1206  * stream-compatible, because this matches the behaviour of the old code.
1207  *
1208  * If nothing else, we bind to 7/1/1 - the unidirectional interface.
1209  */
1210 static int usblp_select_alts(struct usblp *usblp)
1211 {
1212 	struct usb_interface *if_alt;
1213 	struct usb_host_interface *ifd;
1214 	struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1215 	int p, i, e;
1216 
1217 	if_alt = usblp->intf;
1218 
1219 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1220 		usblp->protocol[p].alt_setting = -1;
1221 
1222 	/* Find out what we have. */
1223 	for (i = 0; i < if_alt->num_altsetting; i++) {
1224 		ifd = &if_alt->altsetting[i];
1225 
1226 		if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
1227 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1228 				continue;
1229 
1230 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1231 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1232 			continue;
1233 
1234 		/* Look for bulk OUT and IN endpoints. */
1235 		epwrite = epread = NULL;
1236 		for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1237 			epd = &ifd->endpoint[e].desc;
1238 
1239 			if (usb_endpoint_is_bulk_out(epd))
1240 				if (!epwrite)
1241 					epwrite = epd;
1242 
1243 			if (usb_endpoint_is_bulk_in(epd))
1244 				if (!epread)
1245 					epread = epd;
1246 		}
1247 
1248 		/* Ignore buggy hardware without the right endpoints. */
1249 		if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1250 			continue;
1251 
1252 		/* Turn off reads for 7/1/1 (unidirectional) interfaces
1253 		 * and buggy bidirectional printers. */
1254 		if (ifd->desc.bInterfaceProtocol == 1) {
1255 			epread = NULL;
1256 		} else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1257 			printk(KERN_INFO "usblp%d: Disabling reads from "
1258 			    "problematic bidirectional printer\n",
1259 			    usblp->minor);
1260 			epread = NULL;
1261 		}
1262 
1263 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1264 				ifd->desc.bAlternateSetting;
1265 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1266 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1267 	}
1268 
1269 	/* If our requested protocol is supported, then use it. */
1270 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1271 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1272 	    usblp->protocol[proto_bias].alt_setting != -1)
1273 		return proto_bias;
1274 
1275 	/* Ordering is important here. */
1276 	if (usblp->protocol[2].alt_setting != -1)
1277 		return 2;
1278 	if (usblp->protocol[1].alt_setting != -1)
1279 		return 1;
1280 	if (usblp->protocol[3].alt_setting != -1)
1281 		return 3;
1282 
1283 	/* If nothing is available, then don't bind to this device. */
1284 	return -1;
1285 }
1286 
1287 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1288 {
1289 	int r, alts;
1290 
1291 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1292 		return -EINVAL;
1293 
1294 	alts = usblp->protocol[protocol].alt_setting;
1295 	if (alts < 0)
1296 		return -EINVAL;
1297 	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1298 	if (r < 0) {
1299 		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1300 			alts, usblp->ifnum);
1301 		return r;
1302 	}
1303 
1304 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1305 	usblp->current_protocol = protocol;
1306 	dbg("usblp%d set protocol %d", usblp->minor, protocol);
1307 	return 0;
1308 }
1309 
1310 /* Retrieves and caches device ID string.
1311  * Returns length, including length bytes but not null terminator.
1312  * On error, returns a negative errno value. */
1313 static int usblp_cache_device_id_string(struct usblp *usblp)
1314 {
1315 	int err, length;
1316 
1317 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1318 	if (err < 0) {
1319 		dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
1320 			usblp->minor, err);
1321 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1322 		return -EIO;
1323 	}
1324 
1325 	/* First two bytes are length in big-endian.
1326 	 * They count themselves, and we copy them into
1327 	 * the user's buffer. */
1328 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1329 	if (length < 2)
1330 		length = 2;
1331 	else if (length >= USBLP_DEVICE_ID_SIZE)
1332 		length = USBLP_DEVICE_ID_SIZE - 1;
1333 	usblp->device_id_string[length] = '\0';
1334 
1335 	dbg("usblp%d Device ID string [len=%d]=\"%s\"",
1336 		usblp->minor, length, &usblp->device_id_string[2]);
1337 
1338 	return length;
1339 }
1340 
1341 static void usblp_disconnect(struct usb_interface *intf)
1342 {
1343 	struct usblp *usblp = usb_get_intfdata(intf);
1344 
1345 	usb_deregister_dev(intf, &usblp_class);
1346 
1347 	if (!usblp || !usblp->dev) {
1348 		dev_err(&intf->dev, "bogus disconnect\n");
1349 		BUG();
1350 	}
1351 
1352 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1353 
1354 	mutex_lock(&usblp_mutex);
1355 	mutex_lock(&usblp->mut);
1356 	usblp->present = 0;
1357 	wake_up(&usblp->wwait);
1358 	wake_up(&usblp->rwait);
1359 	usb_set_intfdata(intf, NULL);
1360 
1361 	usblp_unlink_urbs(usblp);
1362 	mutex_unlock(&usblp->mut);
1363 
1364 	if (!usblp->used)
1365 		usblp_cleanup(usblp);
1366 	mutex_unlock(&usblp_mutex);
1367 }
1368 
1369 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1370 {
1371 	struct usblp *usblp = usb_get_intfdata(intf);
1372 
1373 	usblp_unlink_urbs(usblp);
1374 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1375 	/* not strictly necessary, but just in case */
1376 	wake_up(&usblp->wwait);
1377 	wake_up(&usblp->rwait);
1378 #endif
1379 
1380 	return 0;
1381 }
1382 
1383 static int usblp_resume(struct usb_interface *intf)
1384 {
1385 	struct usblp *usblp = usb_get_intfdata(intf);
1386 	int r;
1387 
1388 	r = handle_bidir(usblp);
1389 
1390 	return r;
1391 }
1392 
1393 static const struct usb_device_id usblp_ids[] = {
1394 	{ USB_DEVICE_INFO(7, 1, 1) },
1395 	{ USB_DEVICE_INFO(7, 1, 2) },
1396 	{ USB_DEVICE_INFO(7, 1, 3) },
1397 	{ USB_INTERFACE_INFO(7, 1, 1) },
1398 	{ USB_INTERFACE_INFO(7, 1, 2) },
1399 	{ USB_INTERFACE_INFO(7, 1, 3) },
1400 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1401 	{ }						/* Terminating entry */
1402 };
1403 
1404 MODULE_DEVICE_TABLE(usb, usblp_ids);
1405 
1406 static struct usb_driver usblp_driver = {
1407 	.name =		"usblp",
1408 	.probe =	usblp_probe,
1409 	.disconnect =	usblp_disconnect,
1410 	.suspend =	usblp_suspend,
1411 	.resume =	usblp_resume,
1412 	.id_table =	usblp_ids,
1413 	.supports_autosuspend =	1,
1414 };
1415 
1416 static int __init usblp_init(void)
1417 {
1418 	return usb_register(&usblp_driver);
1419 }
1420 
1421 static void __exit usblp_exit(void)
1422 {
1423 	usb_deregister(&usblp_driver);
1424 }
1425 
1426 module_init(usblp_init);
1427 module_exit(usblp_exit);
1428 
1429 MODULE_AUTHOR(DRIVER_AUTHOR);
1430 MODULE_DESCRIPTION(DRIVER_DESC);
1431 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1432 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1433 MODULE_LICENSE("GPL");
1434