xref: /linux/drivers/usb/class/usblp.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * usblp.c
4  *
5  * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
6  * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
7  * Copyright (c) 2000 Randy Dunlap	<rdunlap@xenotime.net>
8  * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
9  # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
10  # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
11  * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>
12  *
13  * USB Printer Device Class driver for USB printers and printer cables
14  *
15  * Sponsored by SuSE
16  *
17  * ChangeLog:
18  *	v0.1 - thorough cleaning, URBification, almost a rewrite
19  *	v0.2 - some more cleanups
20  *	v0.3 - cleaner again, waitqueue fixes
21  *	v0.4 - fixes in unidirectional mode
22  *	v0.5 - add DEVICE_ID string support
23  *	v0.6 - never time out
24  *	v0.7 - fixed bulk-IN read and poll (David Paschal)
25  *	v0.8 - add devfs support
26  *	v0.9 - fix unplug-while-open paths
27  *	v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
28  *	v0.11 - add proto_bias option (Pete Zaitcev)
29  *	v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
30  *	v0.13 - alloc space for statusbuf (<status> not on stack);
31  *		use usb_alloc_coherent() for read buf & write buf;
32  *      none  - Maintained in Linux kernel after v0.13
33  */
34 
35 #include <linux/module.h>
36 #include <linux/kernel.h>
37 #include <linux/minmax.h>
38 #include <linux/sched/signal.h>
39 #include <linux/signal.h>
40 #include <linux/poll.h>
41 #include <linux/slab.h>
42 #include <linux/lp.h>
43 #include <linux/mutex.h>
44 #undef DEBUG
45 #include <linux/usb.h>
46 #include <linux/usb/ch9.h>
47 #include <linux/ratelimit.h>
48 
49 /*
50  * Version Information
51  */
52 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
53 #define DRIVER_DESC "USB Printer Device Class driver"
54 
55 #define USBLP_BUF_SIZE		8192
56 #define USBLP_BUF_SIZE_IN	1024
57 #define USBLP_DEVICE_ID_SIZE	1024
58 
59 /* ioctls: */
60 #define IOCNR_GET_DEVICE_ID		1
61 #define IOCNR_GET_PROTOCOLS		2
62 #define IOCNR_SET_PROTOCOL		3
63 #define IOCNR_HP_SET_CHANNEL		4
64 #define IOCNR_GET_BUS_ADDRESS		5
65 #define IOCNR_GET_VID_PID		6
66 #define IOCNR_SOFT_RESET		7
67 /* Get device_id string: */
68 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
69 /* The following ioctls were added for http://hpoj.sourceforge.net:
70  * Get two-int array:
71  * [0]=current protocol
72  *     (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
73  *         3=USB_CLASS_PRINTER/1/3),
74  * [1]=supported protocol mask (mask&(1<<n)!=0 means
75  *     USB_CLASS_PRINTER/1/n supported):
76  */
77 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
78 /*
79  * Set protocol
80  *     (arg: 1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
81  *         3=USB_CLASS_PRINTER/1/3):
82  */
83 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
84 /* Set channel number (HP Vendor-specific command): */
85 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
86 /* Get two-int array: [0]=bus number, [1]=device address: */
87 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
88 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
89 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
90 /* Perform class specific soft reset */
91 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0)
92 
93 /*
94  * A DEVICE_ID string may include the printer's serial number.
95  * It should end with a semi-colon (';').
96  * An example from an HP 970C DeskJet printer is (this is one long string,
97  * with the serial number changed):
98 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:                    ;
99  */
100 
101 /*
102  * USB Printer Requests
103  */
104 
105 #define USBLP_REQ_GET_ID			0x00
106 #define USBLP_REQ_GET_STATUS			0x01
107 #define USBLP_REQ_RESET				0x02
108 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST	0x00	/* HP Vendor-specific */
109 
110 #define USBLP_MINORS		16
111 #define USBLP_MINOR_BASE	0
112 
113 #define USBLP_CTL_TIMEOUT	5000			/* 5 seconds */
114 
115 #define USBLP_FIRST_PROTOCOL	1
116 #define USBLP_LAST_PROTOCOL	3
117 #define USBLP_MAX_PROTOCOLS	(USBLP_LAST_PROTOCOL+1)
118 
119 /*
120  * some arbitrary status buffer size;
121  * need a status buffer that is allocated via kmalloc(), not on stack
122  */
123 #define STATUS_BUF_SIZE		8
124 
125 /*
126  * Locks down the locking order:
127  * ->wmut locks wstatus.
128  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
129  * [rw]status. We only touch status when we know the side idle.
130  * ->lock locks what interrupt accesses.
131  */
132 struct usblp {
133 	struct usb_device	*dev;			/* USB device */
134 	struct mutex		wmut;
135 	struct mutex		mut;
136 	spinlock_t		lock;		/* locks rcomplete, wcomplete */
137 	char			*readbuf;		/* read transfer_buffer */
138 	char			*statusbuf;		/* status transfer_buffer */
139 	struct usb_anchor	urbs;
140 	wait_queue_head_t	rwait, wwait;
141 	int			readcount;		/* Counter for reads */
142 	int			ifnum;			/* Interface number */
143 	struct usb_interface	*intf;			/* The interface */
144 	/*
145 	 * Alternate-setting numbers and endpoints for each protocol
146 	 * (USB_CLASS_PRINTER/1/{index=1,2,3}) that the device supports:
147 	 */
148 	struct {
149 		int				alt_setting;
150 		struct usb_endpoint_descriptor	*epwrite;
151 		struct usb_endpoint_descriptor	*epread;
152 	}			protocol[USBLP_MAX_PROTOCOLS];
153 	int			current_protocol;
154 	int			minor;			/* minor number of device */
155 	int			wcomplete, rcomplete;
156 	int			wstatus;	/* bytes written or error */
157 	int			rstatus;	/* bytes ready or error */
158 	unsigned int		quirks;			/* quirks flags */
159 	unsigned int		flags;			/* mode flags */
160 	unsigned char		used;			/* True if open */
161 	unsigned char		present;		/* True if not disconnected */
162 	unsigned char		bidir;			/* interface is bidirectional */
163 	unsigned char		no_paper;		/* Paper Out happened */
164 	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
165 							/* first 2 bytes are (big-endian) length */
166 };
167 
168 #ifdef DEBUG
169 static void usblp_dump(struct usblp *usblp)
170 {
171 	struct device *dev = &usblp->intf->dev;
172 	int p;
173 
174 	dev_dbg(dev, "usblp=0x%p\n", usblp);
175 	dev_dbg(dev, "dev=0x%p\n", usblp->dev);
176 	dev_dbg(dev, "present=%d\n", usblp->present);
177 	dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
178 	dev_dbg(dev, "readcount=%d\n", usblp->readcount);
179 	dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
180 	for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
181 		dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
182 			usblp->protocol[p].alt_setting);
183 		dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
184 			usblp->protocol[p].epwrite);
185 		dev_dbg(dev, "protocol[%d].epread=%p\n", p,
186 			usblp->protocol[p].epread);
187 	}
188 	dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
189 	dev_dbg(dev, "minor=%d\n", usblp->minor);
190 	dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
191 	dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
192 	dev_dbg(dev, "quirks=%d\n", usblp->quirks);
193 	dev_dbg(dev, "used=%d\n", usblp->used);
194 	dev_dbg(dev, "bidir=%d\n", usblp->bidir);
195 	dev_dbg(dev, "device_id_string=\"%s\"\n",
196 		usblp->device_id_string ?
197 			usblp->device_id_string + 2 :
198 			(unsigned char *)"(null)");
199 }
200 #endif
201 
202 /* Quirks: various printer quirks are handled by this table & its flags. */
203 
204 struct quirk_printer_struct {
205 	__u16 vendorId;
206 	__u16 productId;
207 	unsigned int quirks;
208 };
209 
210 #define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
211 #define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
212 #define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */
213 
214 static const struct quirk_printer_struct quirk_printers[] = {
215 	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
216 	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
217 	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
218 	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
219 	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
220 	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
221 	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
222 	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
223 	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
224 	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
225 	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
226 	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
227 	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
228 	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
229 	{ 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
230 	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
231 	{ 0, 0 }
232 };
233 
234 static int usblp_wwait(struct usblp *usblp, int nonblock);
235 static int usblp_wtest(struct usblp *usblp, int nonblock);
236 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
237 static int usblp_rtest(struct usblp *usblp, int nonblock);
238 static int usblp_submit_read(struct usblp *usblp);
239 static int usblp_select_alts(struct usblp *usblp);
240 static int usblp_set_protocol(struct usblp *usblp, int protocol);
241 static int usblp_cache_device_id_string(struct usblp *usblp);
242 
243 /* forward reference to make our lives easier */
244 static struct usb_driver usblp_driver;
245 static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
246 
247 /*
248  * Functions for usblp control messages.
249  */
250 
251 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
252 {
253 	int retval;
254 	int index = usblp->ifnum;
255 
256 	/* High byte has the interface index.
257 	   Low byte has the alternate setting.
258 	 */
259 	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
260 		index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
261 
262 	retval = usb_control_msg(usblp->dev,
263 		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
264 		request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
265 	dev_dbg(&usblp->intf->dev,
266 		"usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
267 		request, !!dir, recip, value, index, len, retval);
268 	return retval < 0 ? retval : 0;
269 }
270 
271 #define usblp_read_status(usblp, status)\
272 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
273 #define usblp_get_id(usblp, config, id, maxlen)\
274 	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
275 #define usblp_reset(usblp)\
276 	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
277 
278 static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel)
279 {
280 	u8 *buf;
281 	int ret;
282 
283 	buf = kzalloc(1, GFP_KERNEL);
284 	if (!buf)
285 		return -ENOMEM;
286 
287 	ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
288 			USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
289 			channel, buf, 1);
290 	if (ret == 0)
291 		*new_channel = buf[0];
292 
293 	kfree(buf);
294 
295 	return ret;
296 }
297 
298 /*
299  * See the description for usblp_select_alts() below for the usage
300  * explanation.  Look into your /sys/kernel/debug/usb/devices and dmesg in
301  * case of any trouble.
302  */
303 static int proto_bias = -1;
304 
305 /*
306  * URB callback.
307  */
308 
309 static void usblp_bulk_read(struct urb *urb)
310 {
311 	struct usblp *usblp = urb->context;
312 	int status = urb->status;
313 	unsigned long flags;
314 
315 	if (usblp->present && usblp->used) {
316 		if (status)
317 			printk(KERN_WARNING "usblp%d: "
318 			    "nonzero read bulk status received: %d\n",
319 			    usblp->minor, status);
320 	}
321 	spin_lock_irqsave(&usblp->lock, flags);
322 	if (status < 0)
323 		usblp->rstatus = status;
324 	else
325 		usblp->rstatus = urb->actual_length;
326 	usblp->rcomplete = 1;
327 	wake_up(&usblp->rwait);
328 	spin_unlock_irqrestore(&usblp->lock, flags);
329 
330 	usb_free_urb(urb);
331 }
332 
333 static void usblp_bulk_write(struct urb *urb)
334 {
335 	struct usblp *usblp = urb->context;
336 	int status = urb->status;
337 	unsigned long flags;
338 
339 	if (usblp->present && usblp->used) {
340 		if (status)
341 			printk(KERN_WARNING "usblp%d: "
342 			    "nonzero write bulk status received: %d\n",
343 			    usblp->minor, status);
344 	}
345 	spin_lock_irqsave(&usblp->lock, flags);
346 	if (status < 0)
347 		usblp->wstatus = status;
348 	else
349 		usblp->wstatus = urb->actual_length;
350 	usblp->no_paper = 0;
351 	usblp->wcomplete = 1;
352 	wake_up(&usblp->wwait);
353 	spin_unlock_irqrestore(&usblp->lock, flags);
354 
355 	usb_free_urb(urb);
356 }
357 
358 /*
359  * Get and print printer errors.
360  */
361 
362 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
363 
364 static int usblp_check_status(struct usblp *usblp, int err)
365 {
366 	unsigned char status, newerr = 0;
367 	int error;
368 
369 	mutex_lock(&usblp->mut);
370 	error = usblp_read_status(usblp, usblp->statusbuf);
371 	if (error < 0) {
372 		mutex_unlock(&usblp->mut);
373 		printk_ratelimited(KERN_ERR
374 				"usblp%d: error %d reading printer status\n",
375 				usblp->minor, error);
376 		return 0;
377 	}
378 	status = *usblp->statusbuf;
379 	mutex_unlock(&usblp->mut);
380 
381 	if (~status & LP_PERRORP)
382 		newerr = 3;
383 	if (status & LP_POUTPA)
384 		newerr = 1;
385 	if (~status & LP_PSELECD)
386 		newerr = 2;
387 
388 	if (newerr != err) {
389 		printk(KERN_INFO "usblp%d: %s\n",
390 		   usblp->minor, usblp_messages[newerr]);
391 	}
392 
393 	return newerr;
394 }
395 
396 static int handle_bidir(struct usblp *usblp)
397 {
398 	if (usblp->bidir && usblp->used) {
399 		if (usblp_submit_read(usblp) < 0)
400 			return -EIO;
401 	}
402 	return 0;
403 }
404 
405 /*
406  * File op functions.
407  */
408 
409 static int usblp_open(struct inode *inode, struct file *file)
410 {
411 	int minor = iminor(inode);
412 	struct usblp *usblp;
413 	struct usb_interface *intf;
414 	int retval;
415 
416 	if (minor < 0)
417 		return -ENODEV;
418 
419 	mutex_lock(&usblp_mutex);
420 
421 	retval = -ENODEV;
422 	intf = usb_find_interface(&usblp_driver, minor);
423 	if (!intf)
424 		goto out;
425 	usblp = usb_get_intfdata(intf);
426 	if (!usblp || !usblp->dev || !usblp->present)
427 		goto out;
428 
429 	retval = -EBUSY;
430 	if (usblp->used)
431 		goto out;
432 
433 	/*
434 	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
435 	 *  - We do not want persistent state which close(2) does not clear
436 	 *  - It is not used anyway, according to CUPS people
437 	 */
438 
439 	retval = usb_autopm_get_interface(intf);
440 	if (retval < 0)
441 		goto out;
442 	usblp->used = 1;
443 	file->private_data = usblp;
444 
445 	usblp->wcomplete = 1; /* we begin writeable */
446 	usblp->wstatus = 0;
447 	usblp->rcomplete = 0;
448 
449 	if (handle_bidir(usblp) < 0) {
450 		usb_autopm_put_interface(intf);
451 		usblp->used = 0;
452 		file->private_data = NULL;
453 		retval = -EIO;
454 	}
455 out:
456 	mutex_unlock(&usblp_mutex);
457 	return retval;
458 }
459 
460 static void usblp_cleanup(struct usblp *usblp)
461 {
462 	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
463 
464 	kfree(usblp->readbuf);
465 	kfree(usblp->device_id_string);
466 	kfree(usblp->statusbuf);
467 	usb_put_intf(usblp->intf);
468 	kfree(usblp);
469 }
470 
471 static void usblp_unlink_urbs(struct usblp *usblp)
472 {
473 	usb_kill_anchored_urbs(&usblp->urbs);
474 }
475 
476 static int usblp_release(struct inode *inode, struct file *file)
477 {
478 	struct usblp *usblp = file->private_data;
479 
480 	usblp->flags &= ~LP_ABORT;
481 
482 	mutex_lock(&usblp_mutex);
483 	usblp->used = 0;
484 	if (usblp->present)
485 		usblp_unlink_urbs(usblp);
486 
487 	usb_autopm_put_interface(usblp->intf);
488 
489 	if (!usblp->present)		/* finish cleanup from disconnect */
490 		usblp_cleanup(usblp);	/* any URBs must be dead */
491 
492 	mutex_unlock(&usblp_mutex);
493 	return 0;
494 }
495 
496 /* No kernel lock - fine */
497 static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
498 {
499 	struct usblp *usblp = file->private_data;
500 	__poll_t ret = 0;
501 	unsigned long flags;
502 
503 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
504 	poll_wait(file, &usblp->rwait, wait);
505 	poll_wait(file, &usblp->wwait, wait);
506 
507 	mutex_lock(&usblp->mut);
508 	if (!usblp->present)
509 		ret |= EPOLLHUP;
510 	mutex_unlock(&usblp->mut);
511 
512 	spin_lock_irqsave(&usblp->lock, flags);
513 	if (usblp->bidir && usblp->rcomplete)
514 		ret |= EPOLLIN  | EPOLLRDNORM;
515 	if (usblp->no_paper || usblp->wcomplete)
516 		ret |= EPOLLOUT | EPOLLWRNORM;
517 	spin_unlock_irqrestore(&usblp->lock, flags);
518 	return ret;
519 }
520 
521 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
522 {
523 	struct usblp *usblp = file->private_data;
524 	int length, err, i;
525 	unsigned char newChannel;
526 	int status;
527 	int twoints[2];
528 	int retval = 0;
529 
530 	mutex_lock(&usblp->mut);
531 	if (!usblp->present) {
532 		retval = -ENODEV;
533 		goto done;
534 	}
535 
536 	dev_dbg(&usblp->intf->dev,
537 		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
538 		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
539 
540 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
541 
542 		switch (_IOC_NR(cmd)) {
543 
544 		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
545 			if (_IOC_DIR(cmd) != _IOC_READ) {
546 				retval = -EINVAL;
547 				goto done;
548 			}
549 
550 			length = usblp_cache_device_id_string(usblp);
551 			if (length < 0) {
552 				retval = length;
553 				goto done;
554 			}
555 			if (length > _IOC_SIZE(cmd))
556 				length = _IOC_SIZE(cmd); /* truncate */
557 
558 			if (copy_to_user((void __user *) arg,
559 					usblp->device_id_string,
560 					(unsigned long) length)) {
561 				retval = -EFAULT;
562 				goto done;
563 			}
564 
565 			break;
566 
567 		case IOCNR_GET_PROTOCOLS:
568 			if (_IOC_DIR(cmd) != _IOC_READ ||
569 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
570 				retval = -EINVAL;
571 				goto done;
572 			}
573 
574 			twoints[0] = usblp->current_protocol;
575 			twoints[1] = 0;
576 			for (i = USBLP_FIRST_PROTOCOL;
577 			     i <= USBLP_LAST_PROTOCOL; i++) {
578 				if (usblp->protocol[i].alt_setting >= 0)
579 					twoints[1] |= (1<<i);
580 			}
581 
582 			if (copy_to_user((void __user *)arg,
583 					(unsigned char *)twoints,
584 					sizeof(twoints))) {
585 				retval = -EFAULT;
586 				goto done;
587 			}
588 
589 			break;
590 
591 		case IOCNR_SET_PROTOCOL:
592 			if (_IOC_DIR(cmd) != _IOC_WRITE) {
593 				retval = -EINVAL;
594 				goto done;
595 			}
596 
597 #ifdef DEBUG
598 			if (arg == -10) {
599 				usblp_dump(usblp);
600 				break;
601 			}
602 #endif
603 
604 			usblp_unlink_urbs(usblp);
605 			retval = usblp_set_protocol(usblp, arg);
606 			if (retval < 0) {
607 				usblp_set_protocol(usblp,
608 					usblp->current_protocol);
609 			}
610 			break;
611 
612 		case IOCNR_HP_SET_CHANNEL:
613 			if (_IOC_DIR(cmd) != _IOC_WRITE ||
614 			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
615 			    usblp->quirks & USBLP_QUIRK_BIDIR) {
616 				retval = -EINVAL;
617 				goto done;
618 			}
619 
620 			err = usblp_hp_channel_change_request(usblp,
621 				arg, &newChannel);
622 			if (err < 0) {
623 				dev_err(&usblp->dev->dev,
624 					"usblp%d: error = %d setting "
625 					"HP channel\n",
626 					usblp->minor, err);
627 				retval = -EIO;
628 				goto done;
629 			}
630 
631 			dev_dbg(&usblp->intf->dev,
632 				"usblp%d requested/got HP channel %ld/%d\n",
633 				usblp->minor, arg, newChannel);
634 			break;
635 
636 		case IOCNR_GET_BUS_ADDRESS:
637 			if (_IOC_DIR(cmd) != _IOC_READ ||
638 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
639 				retval = -EINVAL;
640 				goto done;
641 			}
642 
643 			twoints[0] = usblp->dev->bus->busnum;
644 			twoints[1] = usblp->dev->devnum;
645 			if (copy_to_user((void __user *)arg,
646 					(unsigned char *)twoints,
647 					sizeof(twoints))) {
648 				retval = -EFAULT;
649 				goto done;
650 			}
651 
652 			dev_dbg(&usblp->intf->dev,
653 				"usblp%d is bus=%d, device=%d\n",
654 				usblp->minor, twoints[0], twoints[1]);
655 			break;
656 
657 		case IOCNR_GET_VID_PID:
658 			if (_IOC_DIR(cmd) != _IOC_READ ||
659 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
660 				retval = -EINVAL;
661 				goto done;
662 			}
663 
664 			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
665 			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
666 			if (copy_to_user((void __user *)arg,
667 					(unsigned char *)twoints,
668 					sizeof(twoints))) {
669 				retval = -EFAULT;
670 				goto done;
671 			}
672 
673 			dev_dbg(&usblp->intf->dev,
674 				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
675 				usblp->minor, twoints[0], twoints[1]);
676 			break;
677 
678 		case IOCNR_SOFT_RESET:
679 			if (_IOC_DIR(cmd) != _IOC_NONE) {
680 				retval = -EINVAL;
681 				goto done;
682 			}
683 			retval = usblp_reset(usblp);
684 			break;
685 		default:
686 			retval = -ENOTTY;
687 		}
688 	else	/* old-style ioctl value */
689 		switch (cmd) {
690 
691 		case LPGETSTATUS:
692 			retval = usblp_read_status(usblp, usblp->statusbuf);
693 			if (retval) {
694 				printk_ratelimited(KERN_ERR "usblp%d:"
695 					    "failed reading printer status (%d)\n",
696 					    usblp->minor, retval);
697 				retval = -EIO;
698 				goto done;
699 			}
700 			status = *usblp->statusbuf;
701 			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
702 				retval = -EFAULT;
703 			break;
704 
705 		case LPABORT:
706 			if (arg)
707 				usblp->flags |= LP_ABORT;
708 			else
709 				usblp->flags &= ~LP_ABORT;
710 			break;
711 
712 		default:
713 			retval = -ENOTTY;
714 		}
715 
716 done:
717 	mutex_unlock(&usblp->mut);
718 	return retval;
719 }
720 
721 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
722 {
723 	struct urb *urb;
724 	char *writebuf;
725 
726 	writebuf = kmalloc(transfer_length, GFP_KERNEL);
727 	if (writebuf == NULL)
728 		return NULL;
729 	urb = usb_alloc_urb(0, GFP_KERNEL);
730 	if (urb == NULL) {
731 		kfree(writebuf);
732 		return NULL;
733 	}
734 
735 	usb_fill_bulk_urb(urb, usblp->dev,
736 		usb_sndbulkpipe(usblp->dev,
737 		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
738 		writebuf, transfer_length, usblp_bulk_write, usblp);
739 	urb->transfer_flags |= URB_FREE_BUFFER;
740 
741 	return urb;
742 }
743 
744 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
745 {
746 	struct usblp *usblp = file->private_data;
747 	struct urb *writeurb;
748 	int rv;
749 	int transfer_length;
750 	ssize_t writecount = 0;
751 
752 	if (mutex_lock_interruptible(&usblp->wmut)) {
753 		rv = -EINTR;
754 		goto raise_biglock;
755 	}
756 	rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK));
757 	if (rv < 0)
758 		goto raise_wait;
759 
760 	while (writecount < count) {
761 		/*
762 		 * Step 1: Submit next block.
763 		 */
764 		transfer_length = count - writecount;
765 		if (transfer_length > USBLP_BUF_SIZE)
766 			transfer_length = USBLP_BUF_SIZE;
767 
768 		rv = -ENOMEM;
769 		writeurb = usblp_new_writeurb(usblp, transfer_length);
770 		if (writeurb == NULL)
771 			goto raise_urb;
772 		usb_anchor_urb(writeurb, &usblp->urbs);
773 
774 		if (copy_from_user(writeurb->transfer_buffer,
775 				   buffer + writecount, transfer_length)) {
776 			rv = -EFAULT;
777 			goto raise_badaddr;
778 		}
779 
780 		spin_lock_irq(&usblp->lock);
781 		usblp->wcomplete = 0;
782 		spin_unlock_irq(&usblp->lock);
783 
784 		rv = usb_submit_urb(writeurb, GFP_KERNEL);
785 		if (rv < 0) {
786 			usblp->wstatus = 0;
787 			spin_lock_irq(&usblp->lock);
788 			usblp->no_paper = 0;
789 			usblp->wcomplete = 1;
790 			wake_up(&usblp->wwait);
791 			spin_unlock_irq(&usblp->lock);
792 			if (rv != -ENOMEM)
793 				rv = -EIO;
794 			goto raise_submit;
795 		}
796 
797 		/*
798 		 * Step 2: Wait for transfer to end, collect results.
799 		 */
800 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
801 		if (rv < 0) {
802 			if (rv == -EAGAIN) {
803 				/* Presume that it's going to complete well. */
804 				writecount += transfer_length;
805 			}
806 			if (rv == -ENOSPC) {
807 				spin_lock_irq(&usblp->lock);
808 				usblp->no_paper = 1;	/* Mark for poll(2) */
809 				spin_unlock_irq(&usblp->lock);
810 				writecount += transfer_length;
811 			}
812 			/* Leave URB dangling, to be cleaned on close. */
813 			goto collect_error;
814 		}
815 
816 		if (usblp->wstatus < 0) {
817 			rv = -EIO;
818 			goto collect_error;
819 		}
820 		/*
821 		 * This is critical: it must be our URB, not other writer's.
822 		 * The wmut exists mainly to cover us here.
823 		 */
824 		writecount += usblp->wstatus;
825 	}
826 
827 	mutex_unlock(&usblp->wmut);
828 	return writecount;
829 
830 raise_submit:
831 raise_badaddr:
832 	usb_unanchor_urb(writeurb);
833 	usb_free_urb(writeurb);
834 raise_urb:
835 raise_wait:
836 collect_error:		/* Out of raise sequence */
837 	mutex_unlock(&usblp->wmut);
838 raise_biglock:
839 	return writecount ? writecount : rv;
840 }
841 
842 /*
843  * Notice that we fail to restart in a few cases: on EFAULT, on restart
844  * error, etc. This is the historical behaviour. In all such cases we return
845  * EIO, and applications loop in order to get the new read going.
846  */
847 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
848 {
849 	struct usblp *usblp = file->private_data;
850 	ssize_t count;
851 	ssize_t avail;
852 	int rv;
853 
854 	if (!usblp->bidir)
855 		return -EINVAL;
856 
857 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
858 	if (rv < 0)
859 		return rv;
860 
861 	if (!usblp->present) {
862 		count = -ENODEV;
863 		goto done;
864 	}
865 
866 	avail = usblp->rstatus;
867 	if (avail < 0) {
868 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
869 			usblp->minor, (int)avail);
870 		usblp_submit_read(usblp);
871 		count = -EIO;
872 		goto done;
873 	}
874 
875 	count = min_t(ssize_t, len, avail - usblp->readcount);
876 	if (count != 0 &&
877 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
878 		count = -EFAULT;
879 		goto done;
880 	}
881 
882 	usblp->readcount += count;
883 	if (usblp->readcount == avail) {
884 		if (usblp_submit_read(usblp) < 0) {
885 			/* We don't want to leak USB return codes into errno. */
886 			if (count == 0)
887 				count = -EIO;
888 			goto done;
889 		}
890 	}
891 
892 done:
893 	mutex_unlock(&usblp->mut);
894 	return count;
895 }
896 
897 /*
898  * Wait for the write path to come idle.
899  * This is called under the ->wmut, so the idle path stays idle.
900  *
901  * Our write path has a peculiar property: it does not buffer like a tty,
902  * but waits for the write to succeed. This allows our ->release to bug out
903  * without waiting for writes to drain. But it obviously does not work
904  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
905  * select(2) or poll(2) to wait for the buffer to drain before closing.
906  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
907  */
908 static int usblp_wwait(struct usblp *usblp, int nonblock)
909 {
910 	DECLARE_WAITQUEUE(waita, current);
911 	int rc;
912 	int err = 0;
913 
914 	add_wait_queue(&usblp->wwait, &waita);
915 	for (;;) {
916 		if (mutex_lock_interruptible(&usblp->mut)) {
917 			rc = -EINTR;
918 			break;
919 		}
920 		set_current_state(TASK_INTERRUPTIBLE);
921 		rc = usblp_wtest(usblp, nonblock);
922 		mutex_unlock(&usblp->mut);
923 		if (rc <= 0)
924 			break;
925 
926 		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
927 			if (usblp->flags & LP_ABORT) {
928 				err = usblp_check_status(usblp, err);
929 				if (err == 1) {	/* Paper out */
930 					rc = -ENOSPC;
931 					break;
932 				}
933 			} else {
934 				/* Prod the printer, Gentoo#251237. */
935 				mutex_lock(&usblp->mut);
936 				usblp_read_status(usblp, usblp->statusbuf);
937 				mutex_unlock(&usblp->mut);
938 			}
939 		}
940 	}
941 	set_current_state(TASK_RUNNING);
942 	remove_wait_queue(&usblp->wwait, &waita);
943 	return rc;
944 }
945 
946 static int usblp_wtest(struct usblp *usblp, int nonblock)
947 {
948 	unsigned long flags;
949 
950 	if (!usblp->present)
951 		return -ENODEV;
952 	if (signal_pending(current))
953 		return -EINTR;
954 	spin_lock_irqsave(&usblp->lock, flags);
955 	if (usblp->wcomplete) {
956 		spin_unlock_irqrestore(&usblp->lock, flags);
957 		return 0;
958 	}
959 	spin_unlock_irqrestore(&usblp->lock, flags);
960 	if (nonblock)
961 		return -EAGAIN;
962 	return 1;
963 }
964 
965 /*
966  * Wait for read bytes to become available. This probably should have been
967  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
968  * name for functions which lock and return.
969  *
970  * We do not use wait_event_interruptible because it makes locking iffy.
971  */
972 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
973 {
974 	DECLARE_WAITQUEUE(waita, current);
975 	int rc;
976 
977 	add_wait_queue(&usblp->rwait, &waita);
978 	for (;;) {
979 		if (mutex_lock_interruptible(&usblp->mut)) {
980 			rc = -EINTR;
981 			break;
982 		}
983 		set_current_state(TASK_INTERRUPTIBLE);
984 		rc = usblp_rtest(usblp, nonblock);
985 		if (rc < 0) {
986 			mutex_unlock(&usblp->mut);
987 			break;
988 		}
989 		if (rc == 0)	/* Keep it locked */
990 			break;
991 		mutex_unlock(&usblp->mut);
992 		schedule();
993 	}
994 	set_current_state(TASK_RUNNING);
995 	remove_wait_queue(&usblp->rwait, &waita);
996 	return rc;
997 }
998 
999 static int usblp_rtest(struct usblp *usblp, int nonblock)
1000 {
1001 	unsigned long flags;
1002 
1003 	if (!usblp->present)
1004 		return -ENODEV;
1005 	if (signal_pending(current))
1006 		return -EINTR;
1007 	spin_lock_irqsave(&usblp->lock, flags);
1008 	if (usblp->rcomplete) {
1009 		spin_unlock_irqrestore(&usblp->lock, flags);
1010 		return 0;
1011 	}
1012 	spin_unlock_irqrestore(&usblp->lock, flags);
1013 	if (nonblock)
1014 		return -EAGAIN;
1015 	return 1;
1016 }
1017 
1018 /*
1019  * Please check ->bidir and other such things outside for now.
1020  */
1021 static int usblp_submit_read(struct usblp *usblp)
1022 {
1023 	struct urb *urb;
1024 	unsigned long flags;
1025 	int rc;
1026 
1027 	rc = -ENOMEM;
1028 	urb = usb_alloc_urb(0, GFP_KERNEL);
1029 	if (urb == NULL)
1030 		goto raise_urb;
1031 
1032 	usb_fill_bulk_urb(urb, usblp->dev,
1033 		usb_rcvbulkpipe(usblp->dev,
1034 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
1035 		usblp->readbuf, USBLP_BUF_SIZE_IN,
1036 		usblp_bulk_read, usblp);
1037 	usb_anchor_urb(urb, &usblp->urbs);
1038 
1039 	spin_lock_irqsave(&usblp->lock, flags);
1040 	usblp->readcount = 0; /* XXX Why here? */
1041 	usblp->rcomplete = 0;
1042 	spin_unlock_irqrestore(&usblp->lock, flags);
1043 	rc = usb_submit_urb(urb, GFP_KERNEL);
1044 	if (rc < 0) {
1045 		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1046 		spin_lock_irqsave(&usblp->lock, flags);
1047 		usblp->rstatus = rc;
1048 		usblp->rcomplete = 1;
1049 		spin_unlock_irqrestore(&usblp->lock, flags);
1050 		goto raise_submit;
1051 	}
1052 
1053 	return 0;
1054 
1055 raise_submit:
1056 	usb_unanchor_urb(urb);
1057 	usb_free_urb(urb);
1058 raise_urb:
1059 	return rc;
1060 }
1061 
1062 /*
1063  * Checks for printers that have quirks, such as requiring unidirectional
1064  * communication but reporting bidirectional; currently some HP printers
1065  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1066  * sent at each open (like some Epsons).
1067  * Returns 1 if found, 0 if not found.
1068  *
1069  * HP recommended that we use the bidirectional interface but
1070  * don't attempt any bulk IN transfers from the IN endpoint.
1071  * Here's some more detail on the problem:
1072  * The problem is not that it isn't bidirectional though. The problem
1073  * is that if you request a device ID, or status information, while
1074  * the buffers are full, the return data will end up in the print data
1075  * buffer. For example if you make sure you never request the device ID
1076  * while you are sending print data, and you don't try to query the
1077  * printer status every couple of milliseconds, you will probably be OK.
1078  */
1079 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1080 {
1081 	int i;
1082 
1083 	for (i = 0; quirk_printers[i].vendorId; i++) {
1084 		if (vendor == quirk_printers[i].vendorId &&
1085 		    product == quirk_printers[i].productId)
1086 			return quirk_printers[i].quirks;
1087 	}
1088 	return 0;
1089 }
1090 
1091 static const struct file_operations usblp_fops = {
1092 	.owner =	THIS_MODULE,
1093 	.read =		usblp_read,
1094 	.write =	usblp_write,
1095 	.poll =		usblp_poll,
1096 	.unlocked_ioctl =	usblp_ioctl,
1097 	.compat_ioctl =		usblp_ioctl,
1098 	.open =		usblp_open,
1099 	.release =	usblp_release,
1100 	.llseek =	noop_llseek,
1101 };
1102 
1103 static char *usblp_devnode(const struct device *dev, umode_t *mode)
1104 {
1105 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1106 }
1107 
1108 static struct usb_class_driver usblp_class = {
1109 	.name =		"lp%d",
1110 	.devnode =	usblp_devnode,
1111 	.fops =		&usblp_fops,
1112 	.minor_base =	USBLP_MINOR_BASE,
1113 };
1114 
1115 static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1116 {
1117 	struct usb_interface *intf = to_usb_interface(dev);
1118 	struct usblp *usblp = usb_get_intfdata(intf);
1119 
1120 	if (usblp->device_id_string[0] == 0 &&
1121 	    usblp->device_id_string[1] == 0)
1122 		return 0;
1123 
1124 	return sprintf(buf, "%s", usblp->device_id_string+2);
1125 }
1126 
1127 static DEVICE_ATTR_RO(ieee1284_id);
1128 
1129 static struct attribute *usblp_attrs[] = {
1130 	&dev_attr_ieee1284_id.attr,
1131 	NULL,
1132 };
1133 ATTRIBUTE_GROUPS(usblp);
1134 
1135 static int usblp_probe(struct usb_interface *intf,
1136 		       const struct usb_device_id *id)
1137 {
1138 	struct usb_device *dev = interface_to_usbdev(intf);
1139 	struct usblp *usblp;
1140 	int protocol;
1141 	int retval;
1142 
1143 	/* Malloc and start initializing usblp structure so we can use it
1144 	 * directly. */
1145 	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1146 	if (!usblp) {
1147 		retval = -ENOMEM;
1148 		goto abort_ret;
1149 	}
1150 	usblp->dev = dev;
1151 	mutex_init(&usblp->wmut);
1152 	mutex_init(&usblp->mut);
1153 	spin_lock_init(&usblp->lock);
1154 	init_waitqueue_head(&usblp->rwait);
1155 	init_waitqueue_head(&usblp->wwait);
1156 	init_usb_anchor(&usblp->urbs);
1157 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1158 	usblp->intf = usb_get_intf(intf);
1159 
1160 	/* Malloc device ID string buffer to the largest expected length,
1161 	 * since we can re-query it on an ioctl and a dynamic string
1162 	 * could change in length. */
1163 	usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL);
1164 	if (!usblp->device_id_string) {
1165 		retval = -ENOMEM;
1166 		goto abort;
1167 	}
1168 
1169 	/*
1170 	 * Allocate read buffer. We somewhat wastefully
1171 	 * malloc both regardless of bidirectionality, because the
1172 	 * alternate setting can be changed later via an ioctl.
1173 	 */
1174 	usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL);
1175 	if (!usblp->readbuf) {
1176 		retval = -ENOMEM;
1177 		goto abort;
1178 	}
1179 
1180 	/* Allocate buffer for printer status */
1181 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1182 	if (!usblp->statusbuf) {
1183 		retval = -ENOMEM;
1184 		goto abort;
1185 	}
1186 
1187 	/* Lookup quirks for this printer. */
1188 	usblp->quirks = usblp_quirks(
1189 		le16_to_cpu(dev->descriptor.idVendor),
1190 		le16_to_cpu(dev->descriptor.idProduct));
1191 
1192 	/* Analyze and pick initial alternate settings and endpoints. */
1193 	protocol = usblp_select_alts(usblp);
1194 	if (protocol < 0) {
1195 		dev_dbg(&intf->dev,
1196 			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1197 			le16_to_cpu(dev->descriptor.idVendor),
1198 			le16_to_cpu(dev->descriptor.idProduct));
1199 		retval = -ENODEV;
1200 		goto abort;
1201 	}
1202 
1203 	/* Setup the selected alternate setting and endpoints. */
1204 	if (usblp_set_protocol(usblp, protocol) < 0) {
1205 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1206 		goto abort;
1207 	}
1208 
1209 	/* Retrieve and store the device ID string. */
1210 	usblp_cache_device_id_string(usblp);
1211 
1212 #ifdef DEBUG
1213 	usblp_check_status(usblp, 0);
1214 #endif
1215 
1216 	usb_set_intfdata(intf, usblp);
1217 
1218 	usblp->present = 1;
1219 
1220 	retval = usb_register_dev(intf, &usblp_class);
1221 	if (retval) {
1222 		dev_err(&intf->dev,
1223 			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1224 			USBLP_MINOR_BASE, retval);
1225 		goto abort_intfdata;
1226 	}
1227 	usblp->minor = intf->minor;
1228 	dev_info(&intf->dev,
1229 		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1230 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1231 		usblp->ifnum,
1232 		usblp->protocol[usblp->current_protocol].alt_setting,
1233 		usblp->current_protocol,
1234 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1235 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1236 
1237 	return 0;
1238 
1239 abort_intfdata:
1240 	usb_set_intfdata(intf, NULL);
1241 abort:
1242 	kfree(usblp->readbuf);
1243 	kfree(usblp->statusbuf);
1244 	kfree(usblp->device_id_string);
1245 	usb_put_intf(usblp->intf);
1246 	kfree(usblp);
1247 abort_ret:
1248 	return retval;
1249 }
1250 
1251 /*
1252  * We are a "new" style driver with usb_device_id table,
1253  * but our requirements are too intricate for simple match to handle.
1254  *
1255  * The "proto_bias" option may be used to specify the preferred protocol
1256  * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1257  * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1258  * then we bind to it.
1259  *
1260  * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1261  * is compatible with a stream of characters. If we find it, we bind to it.
1262  *
1263  * Note that the people from hpoj.sourceforge.net need to be able to
1264  * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1265  * for this purpose.
1266  *
1267  * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1268  * even though it's probably not stream-compatible, because this matches
1269  * the behaviour of the old code.
1270  *
1271  * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1272  * - the unidirectional interface.
1273  */
1274 static int usblp_select_alts(struct usblp *usblp)
1275 {
1276 	struct usb_interface *if_alt;
1277 	struct usb_host_interface *ifd;
1278 	struct usb_endpoint_descriptor *epwrite, *epread;
1279 	int p, i;
1280 	int res;
1281 
1282 	if_alt = usblp->intf;
1283 
1284 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1285 		usblp->protocol[p].alt_setting = -1;
1286 
1287 	/* Find out what we have. */
1288 	for (i = 0; i < if_alt->num_altsetting; i++) {
1289 		ifd = &if_alt->altsetting[i];
1290 
1291 		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1292 		    ifd->desc.bInterfaceSubClass != 1)
1293 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1294 				continue;
1295 
1296 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1297 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1298 			continue;
1299 
1300 		/* Look for the expected bulk endpoints. */
1301 		if (ifd->desc.bInterfaceProtocol > 1) {
1302 			res = usb_find_common_endpoints(ifd,
1303 					&epread, &epwrite, NULL, NULL);
1304 		} else {
1305 			epread = NULL;
1306 			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1307 		}
1308 
1309 		/* Ignore buggy hardware without the right endpoints. */
1310 		if (res)
1311 			continue;
1312 
1313 		/* Turn off reads for buggy bidirectional printers. */
1314 		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1315 			printk(KERN_INFO "usblp%d: Disabling reads from "
1316 			    "problematic bidirectional printer\n",
1317 			    usblp->minor);
1318 			epread = NULL;
1319 		}
1320 
1321 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1322 				ifd->desc.bAlternateSetting;
1323 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1324 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1325 	}
1326 
1327 	/* If our requested protocol is supported, then use it. */
1328 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1329 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1330 	    usblp->protocol[proto_bias].alt_setting != -1)
1331 		return proto_bias;
1332 
1333 	/* Ordering is important here. */
1334 	if (usblp->protocol[2].alt_setting != -1)
1335 		return 2;
1336 	if (usblp->protocol[1].alt_setting != -1)
1337 		return 1;
1338 	if (usblp->protocol[3].alt_setting != -1)
1339 		return 3;
1340 
1341 	/* If nothing is available, then don't bind to this device. */
1342 	return -1;
1343 }
1344 
1345 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1346 {
1347 	int r, alts;
1348 
1349 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1350 		return -EINVAL;
1351 
1352 	alts = usblp->protocol[protocol].alt_setting;
1353 	if (alts < 0)
1354 		return -EINVAL;
1355 
1356 	/* Don't unnecessarily set the interface if there's a single alt. */
1357 	if (usblp->intf->num_altsetting > 1) {
1358 		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1359 		if (r < 0) {
1360 			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1361 				alts, usblp->ifnum);
1362 			return r;
1363 		}
1364 	}
1365 
1366 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1367 	usblp->current_protocol = protocol;
1368 	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1369 		usblp->minor, protocol);
1370 	return 0;
1371 }
1372 
1373 /* Retrieves and caches device ID string.
1374  * Returns length, including length bytes but not null terminator.
1375  * On error, returns a negative errno value. */
1376 static int usblp_cache_device_id_string(struct usblp *usblp)
1377 {
1378 	int err, length;
1379 
1380 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1381 	if (err < 0) {
1382 		dev_dbg(&usblp->intf->dev,
1383 			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1384 			usblp->minor, err);
1385 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1386 		return -EIO;
1387 	}
1388 
1389 	/* First two bytes are length in big-endian.
1390 	 * They count themselves, and we copy them into
1391 	 * the user's buffer. */
1392 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1393 	if (length < 2)
1394 		length = 2;
1395 	else if (length >= USBLP_DEVICE_ID_SIZE)
1396 		length = USBLP_DEVICE_ID_SIZE - 1;
1397 	usblp->device_id_string[length] = '\0';
1398 
1399 	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1400 		usblp->minor, length, &usblp->device_id_string[2]);
1401 
1402 	return length;
1403 }
1404 
1405 static void usblp_disconnect(struct usb_interface *intf)
1406 {
1407 	struct usblp *usblp = usb_get_intfdata(intf);
1408 
1409 	usb_deregister_dev(intf, &usblp_class);
1410 
1411 	if (!usblp || !usblp->dev) {
1412 		dev_err(&intf->dev, "bogus disconnect\n");
1413 		BUG();
1414 	}
1415 
1416 	mutex_lock(&usblp_mutex);
1417 	mutex_lock(&usblp->mut);
1418 	usblp->present = 0;
1419 	wake_up(&usblp->wwait);
1420 	wake_up(&usblp->rwait);
1421 	usb_set_intfdata(intf, NULL);
1422 
1423 	usblp_unlink_urbs(usblp);
1424 	mutex_unlock(&usblp->mut);
1425 	usb_poison_anchored_urbs(&usblp->urbs);
1426 
1427 	if (!usblp->used)
1428 		usblp_cleanup(usblp);
1429 
1430 	mutex_unlock(&usblp_mutex);
1431 }
1432 
1433 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1434 {
1435 	struct usblp *usblp = usb_get_intfdata(intf);
1436 
1437 	usblp_unlink_urbs(usblp);
1438 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1439 	/* not strictly necessary, but just in case */
1440 	wake_up(&usblp->wwait);
1441 	wake_up(&usblp->rwait);
1442 #endif
1443 
1444 	return 0;
1445 }
1446 
1447 static int usblp_resume(struct usb_interface *intf)
1448 {
1449 	struct usblp *usblp = usb_get_intfdata(intf);
1450 	int r;
1451 
1452 	r = handle_bidir(usblp);
1453 
1454 	return r;
1455 }
1456 
1457 static const struct usb_device_id usblp_ids[] = {
1458 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1459 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1460 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1461 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1462 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1463 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1464 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1465 	{ }						/* Terminating entry */
1466 };
1467 
1468 MODULE_DEVICE_TABLE(usb, usblp_ids);
1469 
1470 static struct usb_driver usblp_driver = {
1471 	.name =		"usblp",
1472 	.probe =	usblp_probe,
1473 	.disconnect =	usblp_disconnect,
1474 	.suspend =	usblp_suspend,
1475 	.resume =	usblp_resume,
1476 	.id_table =	usblp_ids,
1477 	.dev_groups =	usblp_groups,
1478 	.supports_autosuspend =	1,
1479 };
1480 
1481 module_usb_driver(usblp_driver);
1482 
1483 MODULE_AUTHOR(DRIVER_AUTHOR);
1484 MODULE_DESCRIPTION(DRIVER_DESC);
1485 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1486 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1487 MODULE_LICENSE("GPL");
1488