1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * usblp.c
4 *
5 * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
6 * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
7 * Copyright (c) 2000 Randy Dunlap	<rdunlap@xenotime.net>
8 * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
9 # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
10 # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
11 * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>
12 *
13 * USB Printer Device Class driver for USB printers and printer cables
14 *
15 * Sponsored by SuSE
16 *
17 * ChangeLog:
18 *	v0.1 - thorough cleaning, URBification, almost a rewrite
19 *	v0.2 - some more cleanups
20 *	v0.3 - cleaner again, waitqueue fixes
21 *	v0.4 - fixes in unidirectional mode
22 *	v0.5 - add DEVICE_ID string support
23 *	v0.6 - never time out
24 *	v0.7 - fixed bulk-IN read and poll (David Paschal)
25 *	v0.8 - add devfs support
26 *	v0.9 - fix unplug-while-open paths
27 *	v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
28 *	v0.11 - add proto_bias option (Pete Zaitcev)
29 *	v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
30 *	v0.13 - alloc space for statusbuf (<status> not on stack);
31 *		use usb_alloc_coherent() for read buf & write buf;
32 *      none  - Maintained in Linux kernel after v0.13
33 */
34
35#include <linux/module.h>
36#include <linux/kernel.h>
37#include <linux/sched/signal.h>
38#include <linux/signal.h>
39#include <linux/poll.h>
40#include <linux/slab.h>
41#include <linux/lp.h>
42#include <linux/mutex.h>
43#undef DEBUG
44#include <linux/usb.h>
45#include <linux/usb/ch9.h>
46#include <linux/ratelimit.h>
47
48/*
49 * Version Information
50 */
51#define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
52#define DRIVER_DESC "USB Printer Device Class driver"
53
54#define USBLP_BUF_SIZE		8192
55#define USBLP_BUF_SIZE_IN	1024
56#define USBLP_DEVICE_ID_SIZE	1024
57
58/* ioctls: */
59#define IOCNR_GET_DEVICE_ID		1
60#define IOCNR_GET_PROTOCOLS		2
61#define IOCNR_SET_PROTOCOL		3
62#define IOCNR_HP_SET_CHANNEL		4
63#define IOCNR_GET_BUS_ADDRESS		5
64#define IOCNR_GET_VID_PID		6
65#define IOCNR_SOFT_RESET		7
66/* Get device_id string: */
67#define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
68/* The following ioctls were added for http://hpoj.sourceforge.net:
69 * Get two-int array:
70 * [0]=current protocol
71 *     (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
72 *         3=USB_CLASS_PRINTER/1/3),
73 * [1]=supported protocol mask (mask&(1<<n)!=0 means
74 *     USB_CLASS_PRINTER/1/n supported):
75 */
76#define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
77/*
78 * Set protocol
79 *     (arg: 1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
80 *         3=USB_CLASS_PRINTER/1/3):
81 */
82#define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
83/* Set channel number (HP Vendor-specific command): */
84#define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
85/* Get two-int array: [0]=bus number, [1]=device address: */
86#define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
87/* Get two-int array: [0]=vendor ID, [1]=product ID: */
88#define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
89/* Perform class specific soft reset */
90#define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
91
92/*
93 * A DEVICE_ID string may include the printer's serial number.
94 * It should end with a semi-colon (';').
95 * An example from an HP 970C DeskJet printer is (this is one long string,
96 * with the serial number changed):
97MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
98 */
99
100/*
101 * USB Printer Requests
102 */
103
104#define USBLP_REQ_GET_ID			0x00
105#define USBLP_REQ_GET_STATUS			0x01
106#define USBLP_REQ_RESET				0x02
107#define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST	0x00	/* HP Vendor-specific */
108
109#define USBLP_MINORS		16
110#define USBLP_MINOR_BASE	0
111
112#define USBLP_CTL_TIMEOUT	5000			/* 5 seconds */
113
114#define USBLP_FIRST_PROTOCOL	1
115#define USBLP_LAST_PROTOCOL	3
116#define USBLP_MAX_PROTOCOLS	(USBLP_LAST_PROTOCOL+1)
117
118/*
119 * some arbitrary status buffer size;
120 * need a status buffer that is allocated via kmalloc(), not on stack
121 */
122#define STATUS_BUF_SIZE		8
123
124/*
125 * Locks down the locking order:
126 * ->wmut locks wstatus.
127 * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
128 * [rw]status. We only touch status when we know the side idle.
129 * ->lock locks what interrupt accesses.
130 */
131struct usblp {
132	struct usb_device	*dev;			/* USB device */
133	struct mutex		wmut;
134	struct mutex		mut;
135	spinlock_t		lock;		/* locks rcomplete, wcomplete */
136	char			*readbuf;		/* read transfer_buffer */
137	char			*statusbuf;		/* status transfer_buffer */
138	struct usb_anchor	urbs;
139	wait_queue_head_t	rwait, wwait;
140	int			readcount;		/* Counter for reads */
141	int			ifnum;			/* Interface number */
142	struct usb_interface	*intf;			/* The interface */
143	/*
144	 * Alternate-setting numbers and endpoints for each protocol
145	 * (USB_CLASS_PRINTER/1/{index=1,2,3}) that the device supports:
146	 */
147	struct {
148		int				alt_setting;
149		struct usb_endpoint_descriptor	*epwrite;
150		struct usb_endpoint_descriptor	*epread;
151	}			protocol[USBLP_MAX_PROTOCOLS];
152	int			current_protocol;
153	int			minor;			/* minor number of device */
154	int			wcomplete, rcomplete;
155	int			wstatus;	/* bytes written or error */
156	int			rstatus;	/* bytes ready or error */
157	unsigned int		quirks;			/* quirks flags */
158	unsigned int		flags;			/* mode flags */
159	unsigned char		used;			/* True if open */
160	unsigned char		present;		/* True if not disconnected */
161	unsigned char		bidir;			/* interface is bidirectional */
162	unsigned char		no_paper;		/* Paper Out happened */
163	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
164							/* first 2 bytes are (big-endian) length */
165};
166
167#ifdef DEBUG
168static void usblp_dump(struct usblp *usblp)
169{
170	struct device *dev = &usblp->intf->dev;
171	int p;
172
173	dev_dbg(dev, "usblp=0x%p\n", usblp);
174	dev_dbg(dev, "dev=0x%p\n", usblp->dev);
175	dev_dbg(dev, "present=%d\n", usblp->present);
176	dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
177	dev_dbg(dev, "readcount=%d\n", usblp->readcount);
178	dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
179	for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
180		dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
181			usblp->protocol[p].alt_setting);
182		dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
183			usblp->protocol[p].epwrite);
184		dev_dbg(dev, "protocol[%d].epread=%p\n", p,
185			usblp->protocol[p].epread);
186	}
187	dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
188	dev_dbg(dev, "minor=%d\n", usblp->minor);
189	dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
190	dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
191	dev_dbg(dev, "quirks=%d\n", usblp->quirks);
192	dev_dbg(dev, "used=%d\n", usblp->used);
193	dev_dbg(dev, "bidir=%d\n", usblp->bidir);
194	dev_dbg(dev, "device_id_string=\"%s\"\n",
195		usblp->device_id_string ?
196			usblp->device_id_string + 2 :
197			(unsigned char *)"(null)");
198}
199#endif
200
201/* Quirks: various printer quirks are handled by this table & its flags. */
202
203struct quirk_printer_struct {
204	__u16 vendorId;
205	__u16 productId;
206	unsigned int quirks;
207};
208
209#define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
210#define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
211#define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */
212
213static const struct quirk_printer_struct quirk_printers[] = {
214	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
215	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
216	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
217	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
218	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
219	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
220	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
221	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
222	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
223	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
224	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
225	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
226	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
227	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
228	{ 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
229	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
230	{ 0, 0 }
231};
232
233static int usblp_wwait(struct usblp *usblp, int nonblock);
234static int usblp_wtest(struct usblp *usblp, int nonblock);
235static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
236static int usblp_rtest(struct usblp *usblp, int nonblock);
237static int usblp_submit_read(struct usblp *usblp);
238static int usblp_select_alts(struct usblp *usblp);
239static int usblp_set_protocol(struct usblp *usblp, int protocol);
240static int usblp_cache_device_id_string(struct usblp *usblp);
241
242/* forward reference to make our lives easier */
243static struct usb_driver usblp_driver;
244static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
245
246/*
247 * Functions for usblp control messages.
248 */
249
250static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
251{
252	int retval;
253	int index = usblp->ifnum;
254
255	/* High byte has the interface index.
256	   Low byte has the alternate setting.
257	 */
258	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
259		index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
260
261	retval = usb_control_msg(usblp->dev,
262		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
263		request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
264	dev_dbg(&usblp->intf->dev,
265		"usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
266		request, !!dir, recip, value, index, len, retval);
267	return retval < 0 ? retval : 0;
268}
269
270#define usblp_read_status(usblp, status)\
271	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
272#define usblp_get_id(usblp, config, id, maxlen)\
273	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
274#define usblp_reset(usblp)\
275	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
276
277static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel)
278{
279	u8 *buf;
280	int ret;
281
282	buf = kzalloc(1, GFP_KERNEL);
283	if (!buf)
284		return -ENOMEM;
285
286	ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
287			USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
288			channel, buf, 1);
289	if (ret == 0)
290		*new_channel = buf[0];
291
292	kfree(buf);
293
294	return ret;
295}
296
297/*
298 * See the description for usblp_select_alts() below for the usage
299 * explanation.  Look into your /sys/kernel/debug/usb/devices and dmesg in
300 * case of any trouble.
301 */
302static int proto_bias = -1;
303
304/*
305 * URB callback.
306 */
307
308static void usblp_bulk_read(struct urb *urb)
309{
310	struct usblp *usblp = urb->context;
311	int status = urb->status;
312	unsigned long flags;
313
314	if (usblp->present && usblp->used) {
315		if (status)
316			printk(KERN_WARNING "usblp%d: "
317			    "nonzero read bulk status received: %d\n",
318			    usblp->minor, status);
319	}
320	spin_lock_irqsave(&usblp->lock, flags);
321	if (status < 0)
322		usblp->rstatus = status;
323	else
324		usblp->rstatus = urb->actual_length;
325	usblp->rcomplete = 1;
326	wake_up(&usblp->rwait);
327	spin_unlock_irqrestore(&usblp->lock, flags);
328
329	usb_free_urb(urb);
330}
331
332static void usblp_bulk_write(struct urb *urb)
333{
334	struct usblp *usblp = urb->context;
335	int status = urb->status;
336	unsigned long flags;
337
338	if (usblp->present && usblp->used) {
339		if (status)
340			printk(KERN_WARNING "usblp%d: "
341			    "nonzero write bulk status received: %d\n",
342			    usblp->minor, status);
343	}
344	spin_lock_irqsave(&usblp->lock, flags);
345	if (status < 0)
346		usblp->wstatus = status;
347	else
348		usblp->wstatus = urb->actual_length;
349	usblp->no_paper = 0;
350	usblp->wcomplete = 1;
351	wake_up(&usblp->wwait);
352	spin_unlock_irqrestore(&usblp->lock, flags);
353
354	usb_free_urb(urb);
355}
356
357/*
358 * Get and print printer errors.
359 */
360
361static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
362
363static int usblp_check_status(struct usblp *usblp, int err)
364{
365	unsigned char status, newerr = 0;
366	int error;
367
368	mutex_lock(&usblp->mut);
369	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
370		mutex_unlock(&usblp->mut);
371		printk_ratelimited(KERN_ERR
372				"usblp%d: error %d reading printer status\n",
373				usblp->minor, error);
374		return 0;
375	}
376	status = *usblp->statusbuf;
377	mutex_unlock(&usblp->mut);
378
379	if (~status & LP_PERRORP)
380		newerr = 3;
381	if (status & LP_POUTPA)
382		newerr = 1;
383	if (~status & LP_PSELECD)
384		newerr = 2;
385
386	if (newerr != err) {
387		printk(KERN_INFO "usblp%d: %s\n",
388		   usblp->minor, usblp_messages[newerr]);
389	}
390
391	return newerr;
392}
393
394static int handle_bidir(struct usblp *usblp)
395{
396	if (usblp->bidir && usblp->used) {
397		if (usblp_submit_read(usblp) < 0)
398			return -EIO;
399	}
400	return 0;
401}
402
403/*
404 * File op functions.
405 */
406
407static int usblp_open(struct inode *inode, struct file *file)
408{
409	int minor = iminor(inode);
410	struct usblp *usblp;
411	struct usb_interface *intf;
412	int retval;
413
414	if (minor < 0)
415		return -ENODEV;
416
417	mutex_lock(&usblp_mutex);
418
419	retval = -ENODEV;
420	intf = usb_find_interface(&usblp_driver, minor);
421	if (!intf)
422		goto out;
423	usblp = usb_get_intfdata(intf);
424	if (!usblp || !usblp->dev || !usblp->present)
425		goto out;
426
427	retval = -EBUSY;
428	if (usblp->used)
429		goto out;
430
431	/*
432	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
433	 *  - We do not want persistent state which close(2) does not clear
434	 *  - It is not used anyway, according to CUPS people
435	 */
436
437	retval = usb_autopm_get_interface(intf);
438	if (retval < 0)
439		goto out;
440	usblp->used = 1;
441	file->private_data = usblp;
442
443	usblp->wcomplete = 1; /* we begin writeable */
444	usblp->wstatus = 0;
445	usblp->rcomplete = 0;
446
447	if (handle_bidir(usblp) < 0) {
448		usb_autopm_put_interface(intf);
449		usblp->used = 0;
450		file->private_data = NULL;
451		retval = -EIO;
452	}
453out:
454	mutex_unlock(&usblp_mutex);
455	return retval;
456}
457
458static void usblp_cleanup(struct usblp *usblp)
459{
460	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
461
462	kfree(usblp->readbuf);
463	kfree(usblp->device_id_string);
464	kfree(usblp->statusbuf);
465	usb_put_intf(usblp->intf);
466	kfree(usblp);
467}
468
469static void usblp_unlink_urbs(struct usblp *usblp)
470{
471	usb_kill_anchored_urbs(&usblp->urbs);
472}
473
474static int usblp_release(struct inode *inode, struct file *file)
475{
476	struct usblp *usblp = file->private_data;
477
478	usblp->flags &= ~LP_ABORT;
479
480	mutex_lock(&usblp_mutex);
481	usblp->used = 0;
482	if (usblp->present)
483		usblp_unlink_urbs(usblp);
484
485	usb_autopm_put_interface(usblp->intf);
486
487	if (!usblp->present)		/* finish cleanup from disconnect */
488		usblp_cleanup(usblp);	/* any URBs must be dead */
489
490	mutex_unlock(&usblp_mutex);
491	return 0;
492}
493
494/* No kernel lock - fine */
495static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
496{
497	struct usblp *usblp = file->private_data;
498	__poll_t ret = 0;
499	unsigned long flags;
500
501	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
502	poll_wait(file, &usblp->rwait, wait);
503	poll_wait(file, &usblp->wwait, wait);
504
505	mutex_lock(&usblp->mut);
506	if (!usblp->present)
507		ret |= EPOLLHUP;
508	mutex_unlock(&usblp->mut);
509
510	spin_lock_irqsave(&usblp->lock, flags);
511	if (usblp->bidir && usblp->rcomplete)
512		ret |= EPOLLIN  | EPOLLRDNORM;
513	if (usblp->no_paper || usblp->wcomplete)
514		ret |= EPOLLOUT | EPOLLWRNORM;
515	spin_unlock_irqrestore(&usblp->lock, flags);
516	return ret;
517}
518
519static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
520{
521	struct usblp *usblp = file->private_data;
522	int length, err, i;
523	unsigned char newChannel;
524	int status;
525	int twoints[2];
526	int retval = 0;
527
528	mutex_lock(&usblp->mut);
529	if (!usblp->present) {
530		retval = -ENODEV;
531		goto done;
532	}
533
534	dev_dbg(&usblp->intf->dev,
535		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
536		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
537
538	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
539
540		switch (_IOC_NR(cmd)) {
541
542		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
543			if (_IOC_DIR(cmd) != _IOC_READ) {
544				retval = -EINVAL;
545				goto done;
546			}
547
548			length = usblp_cache_device_id_string(usblp);
549			if (length < 0) {
550				retval = length;
551				goto done;
552			}
553			if (length > _IOC_SIZE(cmd))
554				length = _IOC_SIZE(cmd); /* truncate */
555
556			if (copy_to_user((void __user *) arg,
557					usblp->device_id_string,
558					(unsigned long) length)) {
559				retval = -EFAULT;
560				goto done;
561			}
562
563			break;
564
565		case IOCNR_GET_PROTOCOLS:
566			if (_IOC_DIR(cmd) != _IOC_READ ||
567			    _IOC_SIZE(cmd) < sizeof(twoints)) {
568				retval = -EINVAL;
569				goto done;
570			}
571
572			twoints[0] = usblp->current_protocol;
573			twoints[1] = 0;
574			for (i = USBLP_FIRST_PROTOCOL;
575			     i <= USBLP_LAST_PROTOCOL; i++) {
576				if (usblp->protocol[i].alt_setting >= 0)
577					twoints[1] |= (1<<i);
578			}
579
580			if (copy_to_user((void __user *)arg,
581					(unsigned char *)twoints,
582					sizeof(twoints))) {
583				retval = -EFAULT;
584				goto done;
585			}
586
587			break;
588
589		case IOCNR_SET_PROTOCOL:
590			if (_IOC_DIR(cmd) != _IOC_WRITE) {
591				retval = -EINVAL;
592				goto done;
593			}
594
595#ifdef DEBUG
596			if (arg == -10) {
597				usblp_dump(usblp);
598				break;
599			}
600#endif
601
602			usblp_unlink_urbs(usblp);
603			retval = usblp_set_protocol(usblp, arg);
604			if (retval < 0) {
605				usblp_set_protocol(usblp,
606					usblp->current_protocol);
607			}
608			break;
609
610		case IOCNR_HP_SET_CHANNEL:
611			if (_IOC_DIR(cmd) != _IOC_WRITE ||
612			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
613			    usblp->quirks & USBLP_QUIRK_BIDIR) {
614				retval = -EINVAL;
615				goto done;
616			}
617
618			err = usblp_hp_channel_change_request(usblp,
619				arg, &newChannel);
620			if (err < 0) {
621				dev_err(&usblp->dev->dev,
622					"usblp%d: error = %d setting "
623					"HP channel\n",
624					usblp->minor, err);
625				retval = -EIO;
626				goto done;
627			}
628
629			dev_dbg(&usblp->intf->dev,
630				"usblp%d requested/got HP channel %ld/%d\n",
631				usblp->minor, arg, newChannel);
632			break;
633
634		case IOCNR_GET_BUS_ADDRESS:
635			if (_IOC_DIR(cmd) != _IOC_READ ||
636			    _IOC_SIZE(cmd) < sizeof(twoints)) {
637				retval = -EINVAL;
638				goto done;
639			}
640
641			twoints[0] = usblp->dev->bus->busnum;
642			twoints[1] = usblp->dev->devnum;
643			if (copy_to_user((void __user *)arg,
644					(unsigned char *)twoints,
645					sizeof(twoints))) {
646				retval = -EFAULT;
647				goto done;
648			}
649
650			dev_dbg(&usblp->intf->dev,
651				"usblp%d is bus=%d, device=%d\n",
652				usblp->minor, twoints[0], twoints[1]);
653			break;
654
655		case IOCNR_GET_VID_PID:
656			if (_IOC_DIR(cmd) != _IOC_READ ||
657			    _IOC_SIZE(cmd) < sizeof(twoints)) {
658				retval = -EINVAL;
659				goto done;
660			}
661
662			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
663			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
664			if (copy_to_user((void __user *)arg,
665					(unsigned char *)twoints,
666					sizeof(twoints))) {
667				retval = -EFAULT;
668				goto done;
669			}
670
671			dev_dbg(&usblp->intf->dev,
672				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
673				usblp->minor, twoints[0], twoints[1]);
674			break;
675
676		case IOCNR_SOFT_RESET:
677			if (_IOC_DIR(cmd) != _IOC_NONE) {
678				retval = -EINVAL;
679				goto done;
680			}
681			retval = usblp_reset(usblp);
682			break;
683		default:
684			retval = -ENOTTY;
685		}
686	else	/* old-style ioctl value */
687		switch (cmd) {
688
689		case LPGETSTATUS:
690			retval = usblp_read_status(usblp, usblp->statusbuf);
691			if (retval) {
692				printk_ratelimited(KERN_ERR "usblp%d:"
693					    "failed reading printer status (%d)\n",
694					    usblp->minor, retval);
695				retval = -EIO;
696				goto done;
697			}
698			status = *usblp->statusbuf;
699			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
700				retval = -EFAULT;
701			break;
702
703		case LPABORT:
704			if (arg)
705				usblp->flags |= LP_ABORT;
706			else
707				usblp->flags &= ~LP_ABORT;
708			break;
709
710		default:
711			retval = -ENOTTY;
712		}
713
714done:
715	mutex_unlock(&usblp->mut);
716	return retval;
717}
718
719static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
720{
721	struct urb *urb;
722	char *writebuf;
723
724	writebuf = kmalloc(transfer_length, GFP_KERNEL);
725	if (writebuf == NULL)
726		return NULL;
727	urb = usb_alloc_urb(0, GFP_KERNEL);
728	if (urb == NULL) {
729		kfree(writebuf);
730		return NULL;
731	}
732
733	usb_fill_bulk_urb(urb, usblp->dev,
734		usb_sndbulkpipe(usblp->dev,
735		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
736		writebuf, transfer_length, usblp_bulk_write, usblp);
737	urb->transfer_flags |= URB_FREE_BUFFER;
738
739	return urb;
740}
741
742static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
743{
744	struct usblp *usblp = file->private_data;
745	struct urb *writeurb;
746	int rv;
747	int transfer_length;
748	ssize_t writecount = 0;
749
750	if (mutex_lock_interruptible(&usblp->wmut)) {
751		rv = -EINTR;
752		goto raise_biglock;
753	}
754	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
755		goto raise_wait;
756
757	while (writecount < count) {
758		/*
759		 * Step 1: Submit next block.
760		 */
761		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
762			transfer_length = USBLP_BUF_SIZE;
763
764		rv = -ENOMEM;
765		writeurb = usblp_new_writeurb(usblp, transfer_length);
766		if (writeurb == NULL)
767			goto raise_urb;
768		usb_anchor_urb(writeurb, &usblp->urbs);
769
770		if (copy_from_user(writeurb->transfer_buffer,
771				   buffer + writecount, transfer_length)) {
772			rv = -EFAULT;
773			goto raise_badaddr;
774		}
775
776		spin_lock_irq(&usblp->lock);
777		usblp->wcomplete = 0;
778		spin_unlock_irq(&usblp->lock);
779		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
780			usblp->wstatus = 0;
781			spin_lock_irq(&usblp->lock);
782			usblp->no_paper = 0;
783			usblp->wcomplete = 1;
784			wake_up(&usblp->wwait);
785			spin_unlock_irq(&usblp->lock);
786			if (rv != -ENOMEM)
787				rv = -EIO;
788			goto raise_submit;
789		}
790
791		/*
792		 * Step 2: Wait for transfer to end, collect results.
793		 */
794		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
795		if (rv < 0) {
796			if (rv == -EAGAIN) {
797				/* Presume that it's going to complete well. */
798				writecount += transfer_length;
799			}
800			if (rv == -ENOSPC) {
801				spin_lock_irq(&usblp->lock);
802				usblp->no_paper = 1;	/* Mark for poll(2) */
803				spin_unlock_irq(&usblp->lock);
804				writecount += transfer_length;
805			}
806			/* Leave URB dangling, to be cleaned on close. */
807			goto collect_error;
808		}
809
810		if (usblp->wstatus < 0) {
811			rv = -EIO;
812			goto collect_error;
813		}
814		/*
815		 * This is critical: it must be our URB, not other writer's.
816		 * The wmut exists mainly to cover us here.
817		 */
818		writecount += usblp->wstatus;
819	}
820
821	mutex_unlock(&usblp->wmut);
822	return writecount;
823
824raise_submit:
825raise_badaddr:
826	usb_unanchor_urb(writeurb);
827	usb_free_urb(writeurb);
828raise_urb:
829raise_wait:
830collect_error:		/* Out of raise sequence */
831	mutex_unlock(&usblp->wmut);
832raise_biglock:
833	return writecount ? writecount : rv;
834}
835
836/*
837 * Notice that we fail to restart in a few cases: on EFAULT, on restart
838 * error, etc. This is the historical behaviour. In all such cases we return
839 * EIO, and applications loop in order to get the new read going.
840 */
841static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
842{
843	struct usblp *usblp = file->private_data;
844	ssize_t count;
845	ssize_t avail;
846	int rv;
847
848	if (!usblp->bidir)
849		return -EINVAL;
850
851	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
852	if (rv < 0)
853		return rv;
854
855	if (!usblp->present) {
856		count = -ENODEV;
857		goto done;
858	}
859
860	if ((avail = usblp->rstatus) < 0) {
861		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
862		    usblp->minor, (int)avail);
863		usblp_submit_read(usblp);
864		count = -EIO;
865		goto done;
866	}
867
868	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
869	if (count != 0 &&
870	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
871		count = -EFAULT;
872		goto done;
873	}
874
875	if ((usblp->readcount += count) == avail) {
876		if (usblp_submit_read(usblp) < 0) {
877			/* We don't want to leak USB return codes into errno. */
878			if (count == 0)
879				count = -EIO;
880			goto done;
881		}
882	}
883
884done:
885	mutex_unlock(&usblp->mut);
886	return count;
887}
888
889/*
890 * Wait for the write path to come idle.
891 * This is called under the ->wmut, so the idle path stays idle.
892 *
893 * Our write path has a peculiar property: it does not buffer like a tty,
894 * but waits for the write to succeed. This allows our ->release to bug out
895 * without waiting for writes to drain. But it obviously does not work
896 * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
897 * select(2) or poll(2) to wait for the buffer to drain before closing.
898 * Alternatively, set blocking mode with fcntl and issue a zero-size write.
899 */
900static int usblp_wwait(struct usblp *usblp, int nonblock)
901{
902	DECLARE_WAITQUEUE(waita, current);
903	int rc;
904	int err = 0;
905
906	add_wait_queue(&usblp->wwait, &waita);
907	for (;;) {
908		if (mutex_lock_interruptible(&usblp->mut)) {
909			rc = -EINTR;
910			break;
911		}
912		set_current_state(TASK_INTERRUPTIBLE);
913		rc = usblp_wtest(usblp, nonblock);
914		mutex_unlock(&usblp->mut);
915		if (rc <= 0)
916			break;
917
918		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
919			if (usblp->flags & LP_ABORT) {
920				err = usblp_check_status(usblp, err);
921				if (err == 1) {	/* Paper out */
922					rc = -ENOSPC;
923					break;
924				}
925			} else {
926				/* Prod the printer, Gentoo#251237. */
927				mutex_lock(&usblp->mut);
928				usblp_read_status(usblp, usblp->statusbuf);
929				mutex_unlock(&usblp->mut);
930			}
931		}
932	}
933	set_current_state(TASK_RUNNING);
934	remove_wait_queue(&usblp->wwait, &waita);
935	return rc;
936}
937
938static int usblp_wtest(struct usblp *usblp, int nonblock)
939{
940	unsigned long flags;
941
942	if (!usblp->present)
943		return -ENODEV;
944	if (signal_pending(current))
945		return -EINTR;
946	spin_lock_irqsave(&usblp->lock, flags);
947	if (usblp->wcomplete) {
948		spin_unlock_irqrestore(&usblp->lock, flags);
949		return 0;
950	}
951	spin_unlock_irqrestore(&usblp->lock, flags);
952	if (nonblock)
953		return -EAGAIN;
954	return 1;
955}
956
957/*
958 * Wait for read bytes to become available. This probably should have been
959 * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
960 * name for functions which lock and return.
961 *
962 * We do not use wait_event_interruptible because it makes locking iffy.
963 */
964static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
965{
966	DECLARE_WAITQUEUE(waita, current);
967	int rc;
968
969	add_wait_queue(&usblp->rwait, &waita);
970	for (;;) {
971		if (mutex_lock_interruptible(&usblp->mut)) {
972			rc = -EINTR;
973			break;
974		}
975		set_current_state(TASK_INTERRUPTIBLE);
976		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
977			mutex_unlock(&usblp->mut);
978			break;
979		}
980		if (rc == 0)	/* Keep it locked */
981			break;
982		mutex_unlock(&usblp->mut);
983		schedule();
984	}
985	set_current_state(TASK_RUNNING);
986	remove_wait_queue(&usblp->rwait, &waita);
987	return rc;
988}
989
990static int usblp_rtest(struct usblp *usblp, int nonblock)
991{
992	unsigned long flags;
993
994	if (!usblp->present)
995		return -ENODEV;
996	if (signal_pending(current))
997		return -EINTR;
998	spin_lock_irqsave(&usblp->lock, flags);
999	if (usblp->rcomplete) {
1000		spin_unlock_irqrestore(&usblp->lock, flags);
1001		return 0;
1002	}
1003	spin_unlock_irqrestore(&usblp->lock, flags);
1004	if (nonblock)
1005		return -EAGAIN;
1006	return 1;
1007}
1008
1009/*
1010 * Please check ->bidir and other such things outside for now.
1011 */
1012static int usblp_submit_read(struct usblp *usblp)
1013{
1014	struct urb *urb;
1015	unsigned long flags;
1016	int rc;
1017
1018	rc = -ENOMEM;
1019	urb = usb_alloc_urb(0, GFP_KERNEL);
1020	if (urb == NULL)
1021		goto raise_urb;
1022
1023	usb_fill_bulk_urb(urb, usblp->dev,
1024		usb_rcvbulkpipe(usblp->dev,
1025		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
1026		usblp->readbuf, USBLP_BUF_SIZE_IN,
1027		usblp_bulk_read, usblp);
1028	usb_anchor_urb(urb, &usblp->urbs);
1029
1030	spin_lock_irqsave(&usblp->lock, flags);
1031	usblp->readcount = 0; /* XXX Why here? */
1032	usblp->rcomplete = 0;
1033	spin_unlock_irqrestore(&usblp->lock, flags);
1034	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1035		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1036		spin_lock_irqsave(&usblp->lock, flags);
1037		usblp->rstatus = rc;
1038		usblp->rcomplete = 1;
1039		spin_unlock_irqrestore(&usblp->lock, flags);
1040		goto raise_submit;
1041	}
1042
1043	return 0;
1044
1045raise_submit:
1046	usb_unanchor_urb(urb);
1047	usb_free_urb(urb);
1048raise_urb:
1049	return rc;
1050}
1051
1052/*
1053 * Checks for printers that have quirks, such as requiring unidirectional
1054 * communication but reporting bidirectional; currently some HP printers
1055 * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1056 * sent at each open (like some Epsons).
1057 * Returns 1 if found, 0 if not found.
1058 *
1059 * HP recommended that we use the bidirectional interface but
1060 * don't attempt any bulk IN transfers from the IN endpoint.
1061 * Here's some more detail on the problem:
1062 * The problem is not that it isn't bidirectional though. The problem
1063 * is that if you request a device ID, or status information, while
1064 * the buffers are full, the return data will end up in the print data
1065 * buffer. For example if you make sure you never request the device ID
1066 * while you are sending print data, and you don't try to query the
1067 * printer status every couple of milliseconds, you will probably be OK.
1068 */
1069static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1070{
1071	int i;
1072
1073	for (i = 0; quirk_printers[i].vendorId; i++) {
1074		if (vendor == quirk_printers[i].vendorId &&
1075		    product == quirk_printers[i].productId)
1076			return quirk_printers[i].quirks;
1077	}
1078	return 0;
1079}
1080
1081static const struct file_operations usblp_fops = {
1082	.owner =	THIS_MODULE,
1083	.read =		usblp_read,
1084	.write =	usblp_write,
1085	.poll =		usblp_poll,
1086	.unlocked_ioctl =	usblp_ioctl,
1087	.compat_ioctl =		usblp_ioctl,
1088	.open =		usblp_open,
1089	.release =	usblp_release,
1090	.llseek =	noop_llseek,
1091};
1092
1093static char *usblp_devnode(const struct device *dev, umode_t *mode)
1094{
1095	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1096}
1097
1098static struct usb_class_driver usblp_class = {
1099	.name =		"lp%d",
1100	.devnode =	usblp_devnode,
1101	.fops =		&usblp_fops,
1102	.minor_base =	USBLP_MINOR_BASE,
1103};
1104
1105static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1106{
1107	struct usb_interface *intf = to_usb_interface(dev);
1108	struct usblp *usblp = usb_get_intfdata(intf);
1109
1110	if (usblp->device_id_string[0] == 0 &&
1111	    usblp->device_id_string[1] == 0)
1112		return 0;
1113
1114	return sprintf(buf, "%s", usblp->device_id_string+2);
1115}
1116
1117static DEVICE_ATTR_RO(ieee1284_id);
1118
1119static struct attribute *usblp_attrs[] = {
1120	&dev_attr_ieee1284_id.attr,
1121	NULL,
1122};
1123ATTRIBUTE_GROUPS(usblp);
1124
1125static int usblp_probe(struct usb_interface *intf,
1126		       const struct usb_device_id *id)
1127{
1128	struct usb_device *dev = interface_to_usbdev(intf);
1129	struct usblp *usblp;
1130	int protocol;
1131	int retval;
1132
1133	/* Malloc and start initializing usblp structure so we can use it
1134	 * directly. */
1135	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1136	if (!usblp) {
1137		retval = -ENOMEM;
1138		goto abort_ret;
1139	}
1140	usblp->dev = dev;
1141	mutex_init(&usblp->wmut);
1142	mutex_init(&usblp->mut);
1143	spin_lock_init(&usblp->lock);
1144	init_waitqueue_head(&usblp->rwait);
1145	init_waitqueue_head(&usblp->wwait);
1146	init_usb_anchor(&usblp->urbs);
1147	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1148	usblp->intf = usb_get_intf(intf);
1149
1150	/* Malloc device ID string buffer to the largest expected length,
1151	 * since we can re-query it on an ioctl and a dynamic string
1152	 * could change in length. */
1153	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1154		retval = -ENOMEM;
1155		goto abort;
1156	}
1157
1158	/*
1159	 * Allocate read buffer. We somewhat wastefully
1160	 * malloc both regardless of bidirectionality, because the
1161	 * alternate setting can be changed later via an ioctl.
1162	 */
1163	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1164		retval = -ENOMEM;
1165		goto abort;
1166	}
1167
1168	/* Allocate buffer for printer status */
1169	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1170	if (!usblp->statusbuf) {
1171		retval = -ENOMEM;
1172		goto abort;
1173	}
1174
1175	/* Lookup quirks for this printer. */
1176	usblp->quirks = usblp_quirks(
1177		le16_to_cpu(dev->descriptor.idVendor),
1178		le16_to_cpu(dev->descriptor.idProduct));
1179
1180	/* Analyze and pick initial alternate settings and endpoints. */
1181	protocol = usblp_select_alts(usblp);
1182	if (protocol < 0) {
1183		dev_dbg(&intf->dev,
1184			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1185			le16_to_cpu(dev->descriptor.idVendor),
1186			le16_to_cpu(dev->descriptor.idProduct));
1187		retval = -ENODEV;
1188		goto abort;
1189	}
1190
1191	/* Setup the selected alternate setting and endpoints. */
1192	if (usblp_set_protocol(usblp, protocol) < 0) {
1193		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1194		goto abort;
1195	}
1196
1197	/* Retrieve and store the device ID string. */
1198	usblp_cache_device_id_string(usblp);
1199
1200#ifdef DEBUG
1201	usblp_check_status(usblp, 0);
1202#endif
1203
1204	usb_set_intfdata(intf, usblp);
1205
1206	usblp->present = 1;
1207
1208	retval = usb_register_dev(intf, &usblp_class);
1209	if (retval) {
1210		dev_err(&intf->dev,
1211			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1212			USBLP_MINOR_BASE, retval);
1213		goto abort_intfdata;
1214	}
1215	usblp->minor = intf->minor;
1216	dev_info(&intf->dev,
1217		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1218		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1219		usblp->ifnum,
1220		usblp->protocol[usblp->current_protocol].alt_setting,
1221		usblp->current_protocol,
1222		le16_to_cpu(usblp->dev->descriptor.idVendor),
1223		le16_to_cpu(usblp->dev->descriptor.idProduct));
1224
1225	return 0;
1226
1227abort_intfdata:
1228	usb_set_intfdata(intf, NULL);
1229abort:
1230	kfree(usblp->readbuf);
1231	kfree(usblp->statusbuf);
1232	kfree(usblp->device_id_string);
1233	usb_put_intf(usblp->intf);
1234	kfree(usblp);
1235abort_ret:
1236	return retval;
1237}
1238
1239/*
1240 * We are a "new" style driver with usb_device_id table,
1241 * but our requirements are too intricate for simple match to handle.
1242 *
1243 * The "proto_bias" option may be used to specify the preferred protocol
1244 * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1245 * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1246 * then we bind to it.
1247 *
1248 * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1249 * is compatible with a stream of characters. If we find it, we bind to it.
1250 *
1251 * Note that the people from hpoj.sourceforge.net need to be able to
1252 * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1253 * for this purpose.
1254 *
1255 * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1256 * even though it's probably not stream-compatible, because this matches
1257 * the behaviour of the old code.
1258 *
1259 * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1260 * - the unidirectional interface.
1261 */
1262static int usblp_select_alts(struct usblp *usblp)
1263{
1264	struct usb_interface *if_alt;
1265	struct usb_host_interface *ifd;
1266	struct usb_endpoint_descriptor *epwrite, *epread;
1267	int p, i;
1268	int res;
1269
1270	if_alt = usblp->intf;
1271
1272	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1273		usblp->protocol[p].alt_setting = -1;
1274
1275	/* Find out what we have. */
1276	for (i = 0; i < if_alt->num_altsetting; i++) {
1277		ifd = &if_alt->altsetting[i];
1278
1279		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1280		    ifd->desc.bInterfaceSubClass != 1)
1281			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1282				continue;
1283
1284		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1285		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1286			continue;
1287
1288		/* Look for the expected bulk endpoints. */
1289		if (ifd->desc.bInterfaceProtocol > 1) {
1290			res = usb_find_common_endpoints(ifd,
1291					&epread, &epwrite, NULL, NULL);
1292		} else {
1293			epread = NULL;
1294			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1295		}
1296
1297		/* Ignore buggy hardware without the right endpoints. */
1298		if (res)
1299			continue;
1300
1301		/* Turn off reads for buggy bidirectional printers. */
1302		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1303			printk(KERN_INFO "usblp%d: Disabling reads from "
1304			    "problematic bidirectional printer\n",
1305			    usblp->minor);
1306			epread = NULL;
1307		}
1308
1309		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1310				ifd->desc.bAlternateSetting;
1311		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1312		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1313	}
1314
1315	/* If our requested protocol is supported, then use it. */
1316	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1317	    proto_bias <= USBLP_LAST_PROTOCOL &&
1318	    usblp->protocol[proto_bias].alt_setting != -1)
1319		return proto_bias;
1320
1321	/* Ordering is important here. */
1322	if (usblp->protocol[2].alt_setting != -1)
1323		return 2;
1324	if (usblp->protocol[1].alt_setting != -1)
1325		return 1;
1326	if (usblp->protocol[3].alt_setting != -1)
1327		return 3;
1328
1329	/* If nothing is available, then don't bind to this device. */
1330	return -1;
1331}
1332
1333static int usblp_set_protocol(struct usblp *usblp, int protocol)
1334{
1335	int r, alts;
1336
1337	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1338		return -EINVAL;
1339
1340	/* Don't unnecessarily set the interface if there's a single alt. */
1341	if (usblp->intf->num_altsetting > 1) {
1342		alts = usblp->protocol[protocol].alt_setting;
1343		if (alts < 0)
1344			return -EINVAL;
1345		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1346		if (r < 0) {
1347			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1348				alts, usblp->ifnum);
1349			return r;
1350		}
1351	}
1352
1353	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1354	usblp->current_protocol = protocol;
1355	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1356		usblp->minor, protocol);
1357	return 0;
1358}
1359
1360/* Retrieves and caches device ID string.
1361 * Returns length, including length bytes but not null terminator.
1362 * On error, returns a negative errno value. */
1363static int usblp_cache_device_id_string(struct usblp *usblp)
1364{
1365	int err, length;
1366
1367	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1368	if (err < 0) {
1369		dev_dbg(&usblp->intf->dev,
1370			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1371			usblp->minor, err);
1372		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1373		return -EIO;
1374	}
1375
1376	/* First two bytes are length in big-endian.
1377	 * They count themselves, and we copy them into
1378	 * the user's buffer. */
1379	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1380	if (length < 2)
1381		length = 2;
1382	else if (length >= USBLP_DEVICE_ID_SIZE)
1383		length = USBLP_DEVICE_ID_SIZE - 1;
1384	usblp->device_id_string[length] = '\0';
1385
1386	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1387		usblp->minor, length, &usblp->device_id_string[2]);
1388
1389	return length;
1390}
1391
1392static void usblp_disconnect(struct usb_interface *intf)
1393{
1394	struct usblp *usblp = usb_get_intfdata(intf);
1395
1396	usb_deregister_dev(intf, &usblp_class);
1397
1398	if (!usblp || !usblp->dev) {
1399		dev_err(&intf->dev, "bogus disconnect\n");
1400		BUG();
1401	}
1402
1403	mutex_lock(&usblp_mutex);
1404	mutex_lock(&usblp->mut);
1405	usblp->present = 0;
1406	wake_up(&usblp->wwait);
1407	wake_up(&usblp->rwait);
1408	usb_set_intfdata(intf, NULL);
1409
1410	usblp_unlink_urbs(usblp);
1411	mutex_unlock(&usblp->mut);
1412	usb_poison_anchored_urbs(&usblp->urbs);
1413
1414	if (!usblp->used)
1415		usblp_cleanup(usblp);
1416
1417	mutex_unlock(&usblp_mutex);
1418}
1419
1420static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1421{
1422	struct usblp *usblp = usb_get_intfdata(intf);
1423
1424	usblp_unlink_urbs(usblp);
1425#if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1426	/* not strictly necessary, but just in case */
1427	wake_up(&usblp->wwait);
1428	wake_up(&usblp->rwait);
1429#endif
1430
1431	return 0;
1432}
1433
1434static int usblp_resume(struct usb_interface *intf)
1435{
1436	struct usblp *usblp = usb_get_intfdata(intf);
1437	int r;
1438
1439	r = handle_bidir(usblp);
1440
1441	return r;
1442}
1443
1444static const struct usb_device_id usblp_ids[] = {
1445	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1446	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1447	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1448	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1449	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1450	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1451	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1452	{ }						/* Terminating entry */
1453};
1454
1455MODULE_DEVICE_TABLE(usb, usblp_ids);
1456
1457static struct usb_driver usblp_driver = {
1458	.name =		"usblp",
1459	.probe =	usblp_probe,
1460	.disconnect =	usblp_disconnect,
1461	.suspend =	usblp_suspend,
1462	.resume =	usblp_resume,
1463	.id_table =	usblp_ids,
1464	.dev_groups =	usblp_groups,
1465	.supports_autosuspend =	1,
1466};
1467
1468module_usb_driver(usblp_driver);
1469
1470MODULE_AUTHOR(DRIVER_AUTHOR);
1471MODULE_DESCRIPTION(DRIVER_DESC);
1472module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1473MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1474MODULE_LICENSE("GPL");
1475