xref: /openbmc/linux/drivers/usb/class/usblp.c (revision 98ddec80)
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):
97 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:                    ;
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  */
131 struct 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
168 static 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 
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 	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 
277 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
278 	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
279 
280 /*
281  * See the description for usblp_select_alts() below for the usage
282  * explanation.  Look into your /sys/kernel/debug/usb/devices and dmesg in
283  * case of any trouble.
284  */
285 static int proto_bias = -1;
286 
287 /*
288  * URB callback.
289  */
290 
291 static void usblp_bulk_read(struct urb *urb)
292 {
293 	struct usblp *usblp = urb->context;
294 	int status = urb->status;
295 
296 	if (usblp->present && usblp->used) {
297 		if (status)
298 			printk(KERN_WARNING "usblp%d: "
299 			    "nonzero read bulk status received: %d\n",
300 			    usblp->minor, status);
301 	}
302 	spin_lock(&usblp->lock);
303 	if (status < 0)
304 		usblp->rstatus = status;
305 	else
306 		usblp->rstatus = urb->actual_length;
307 	usblp->rcomplete = 1;
308 	wake_up(&usblp->rwait);
309 	spin_unlock(&usblp->lock);
310 
311 	usb_free_urb(urb);
312 }
313 
314 static void usblp_bulk_write(struct urb *urb)
315 {
316 	struct usblp *usblp = urb->context;
317 	int status = urb->status;
318 
319 	if (usblp->present && usblp->used) {
320 		if (status)
321 			printk(KERN_WARNING "usblp%d: "
322 			    "nonzero write bulk status received: %d\n",
323 			    usblp->minor, status);
324 	}
325 	spin_lock(&usblp->lock);
326 	if (status < 0)
327 		usblp->wstatus = status;
328 	else
329 		usblp->wstatus = urb->actual_length;
330 	usblp->no_paper = 0;
331 	usblp->wcomplete = 1;
332 	wake_up(&usblp->wwait);
333 	spin_unlock(&usblp->lock);
334 
335 	usb_free_urb(urb);
336 }
337 
338 /*
339  * Get and print printer errors.
340  */
341 
342 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
343 
344 static int usblp_check_status(struct usblp *usblp, int err)
345 {
346 	unsigned char status, newerr = 0;
347 	int error;
348 
349 	mutex_lock(&usblp->mut);
350 	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
351 		mutex_unlock(&usblp->mut);
352 		printk_ratelimited(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 __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
473 {
474 	__poll_t 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) ? EPOLLIN  | EPOLLRDNORM : 0) |
483 	   ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 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 	dev_dbg(&usblp->intf->dev,
504 		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
505 		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
506 
507 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
508 
509 		switch (_IOC_NR(cmd)) {
510 
511 		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
512 			if (_IOC_DIR(cmd) != _IOC_READ) {
513 				retval = -EINVAL;
514 				goto done;
515 			}
516 
517 			length = usblp_cache_device_id_string(usblp);
518 			if (length < 0) {
519 				retval = length;
520 				goto done;
521 			}
522 			if (length > _IOC_SIZE(cmd))
523 				length = _IOC_SIZE(cmd); /* truncate */
524 
525 			if (copy_to_user((void __user *) arg,
526 					usblp->device_id_string,
527 					(unsigned long) length)) {
528 				retval = -EFAULT;
529 				goto done;
530 			}
531 
532 			break;
533 
534 		case IOCNR_GET_PROTOCOLS:
535 			if (_IOC_DIR(cmd) != _IOC_READ ||
536 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
537 				retval = -EINVAL;
538 				goto done;
539 			}
540 
541 			twoints[0] = usblp->current_protocol;
542 			twoints[1] = 0;
543 			for (i = USBLP_FIRST_PROTOCOL;
544 			     i <= USBLP_LAST_PROTOCOL; i++) {
545 				if (usblp->protocol[i].alt_setting >= 0)
546 					twoints[1] |= (1<<i);
547 			}
548 
549 			if (copy_to_user((void __user *)arg,
550 					(unsigned char *)twoints,
551 					sizeof(twoints))) {
552 				retval = -EFAULT;
553 				goto done;
554 			}
555 
556 			break;
557 
558 		case IOCNR_SET_PROTOCOL:
559 			if (_IOC_DIR(cmd) != _IOC_WRITE) {
560 				retval = -EINVAL;
561 				goto done;
562 			}
563 
564 #ifdef DEBUG
565 			if (arg == -10) {
566 				usblp_dump(usblp);
567 				break;
568 			}
569 #endif
570 
571 			usblp_unlink_urbs(usblp);
572 			retval = usblp_set_protocol(usblp, arg);
573 			if (retval < 0) {
574 				usblp_set_protocol(usblp,
575 					usblp->current_protocol);
576 			}
577 			break;
578 
579 		case IOCNR_HP_SET_CHANNEL:
580 			if (_IOC_DIR(cmd) != _IOC_WRITE ||
581 			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
582 			    usblp->quirks & USBLP_QUIRK_BIDIR) {
583 				retval = -EINVAL;
584 				goto done;
585 			}
586 
587 			err = usblp_hp_channel_change_request(usblp,
588 				arg, &newChannel);
589 			if (err < 0) {
590 				dev_err(&usblp->dev->dev,
591 					"usblp%d: error = %d setting "
592 					"HP channel\n",
593 					usblp->minor, err);
594 				retval = -EIO;
595 				goto done;
596 			}
597 
598 			dev_dbg(&usblp->intf->dev,
599 				"usblp%d requested/got HP channel %ld/%d\n",
600 				usblp->minor, arg, newChannel);
601 			break;
602 
603 		case IOCNR_GET_BUS_ADDRESS:
604 			if (_IOC_DIR(cmd) != _IOC_READ ||
605 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
606 				retval = -EINVAL;
607 				goto done;
608 			}
609 
610 			twoints[0] = usblp->dev->bus->busnum;
611 			twoints[1] = usblp->dev->devnum;
612 			if (copy_to_user((void __user *)arg,
613 					(unsigned char *)twoints,
614 					sizeof(twoints))) {
615 				retval = -EFAULT;
616 				goto done;
617 			}
618 
619 			dev_dbg(&usblp->intf->dev,
620 				"usblp%d is bus=%d, device=%d\n",
621 				usblp->minor, twoints[0], twoints[1]);
622 			break;
623 
624 		case IOCNR_GET_VID_PID:
625 			if (_IOC_DIR(cmd) != _IOC_READ ||
626 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
627 				retval = -EINVAL;
628 				goto done;
629 			}
630 
631 			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
632 			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
633 			if (copy_to_user((void __user *)arg,
634 					(unsigned char *)twoints,
635 					sizeof(twoints))) {
636 				retval = -EFAULT;
637 				goto done;
638 			}
639 
640 			dev_dbg(&usblp->intf->dev,
641 				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
642 				usblp->minor, twoints[0], twoints[1]);
643 			break;
644 
645 		case IOCNR_SOFT_RESET:
646 			if (_IOC_DIR(cmd) != _IOC_NONE) {
647 				retval = -EINVAL;
648 				goto done;
649 			}
650 			retval = usblp_reset(usblp);
651 			break;
652 		default:
653 			retval = -ENOTTY;
654 		}
655 	else	/* old-style ioctl value */
656 		switch (cmd) {
657 
658 		case LPGETSTATUS:
659 			retval = usblp_read_status(usblp, usblp->statusbuf);
660 			if (retval) {
661 				printk_ratelimited(KERN_ERR "usblp%d:"
662 					    "failed reading printer status (%d)\n",
663 					    usblp->minor, retval);
664 				retval = -EIO;
665 				goto done;
666 			}
667 			status = *usblp->statusbuf;
668 			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
669 				retval = -EFAULT;
670 			break;
671 
672 		case LPABORT:
673 			if (arg)
674 				usblp->flags |= LP_ABORT;
675 			else
676 				usblp->flags &= ~LP_ABORT;
677 			break;
678 
679 		default:
680 			retval = -ENOTTY;
681 		}
682 
683 done:
684 	mutex_unlock(&usblp->mut);
685 	return retval;
686 }
687 
688 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
689 {
690 	struct urb *urb;
691 	char *writebuf;
692 
693 	writebuf = kmalloc(transfer_length, GFP_KERNEL);
694 	if (writebuf == NULL)
695 		return NULL;
696 	urb = usb_alloc_urb(0, GFP_KERNEL);
697 	if (urb == NULL) {
698 		kfree(writebuf);
699 		return NULL;
700 	}
701 
702 	usb_fill_bulk_urb(urb, usblp->dev,
703 		usb_sndbulkpipe(usblp->dev,
704 		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
705 		writebuf, transfer_length, usblp_bulk_write, usblp);
706 	urb->transfer_flags |= URB_FREE_BUFFER;
707 
708 	return urb;
709 }
710 
711 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
712 {
713 	struct usblp *usblp = file->private_data;
714 	struct urb *writeurb;
715 	int rv;
716 	int transfer_length;
717 	ssize_t writecount = 0;
718 
719 	if (mutex_lock_interruptible(&usblp->wmut)) {
720 		rv = -EINTR;
721 		goto raise_biglock;
722 	}
723 	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
724 		goto raise_wait;
725 
726 	while (writecount < count) {
727 		/*
728 		 * Step 1: Submit next block.
729 		 */
730 		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
731 			transfer_length = USBLP_BUF_SIZE;
732 
733 		rv = -ENOMEM;
734 		writeurb = usblp_new_writeurb(usblp, transfer_length);
735 		if (writeurb == NULL)
736 			goto raise_urb;
737 		usb_anchor_urb(writeurb, &usblp->urbs);
738 
739 		if (copy_from_user(writeurb->transfer_buffer,
740 				   buffer + writecount, transfer_length)) {
741 			rv = -EFAULT;
742 			goto raise_badaddr;
743 		}
744 
745 		spin_lock_irq(&usblp->lock);
746 		usblp->wcomplete = 0;
747 		spin_unlock_irq(&usblp->lock);
748 		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
749 			usblp->wstatus = 0;
750 			spin_lock_irq(&usblp->lock);
751 			usblp->no_paper = 0;
752 			usblp->wcomplete = 1;
753 			wake_up(&usblp->wwait);
754 			spin_unlock_irq(&usblp->lock);
755 			if (rv != -ENOMEM)
756 				rv = -EIO;
757 			goto raise_submit;
758 		}
759 
760 		/*
761 		 * Step 2: Wait for transfer to end, collect results.
762 		 */
763 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
764 		if (rv < 0) {
765 			if (rv == -EAGAIN) {
766 				/* Presume that it's going to complete well. */
767 				writecount += transfer_length;
768 			}
769 			if (rv == -ENOSPC) {
770 				spin_lock_irq(&usblp->lock);
771 				usblp->no_paper = 1;	/* Mark for poll(2) */
772 				spin_unlock_irq(&usblp->lock);
773 				writecount += transfer_length;
774 			}
775 			/* Leave URB dangling, to be cleaned on close. */
776 			goto collect_error;
777 		}
778 
779 		if (usblp->wstatus < 0) {
780 			rv = -EIO;
781 			goto collect_error;
782 		}
783 		/*
784 		 * This is critical: it must be our URB, not other writer's.
785 		 * The wmut exists mainly to cover us here.
786 		 */
787 		writecount += usblp->wstatus;
788 	}
789 
790 	mutex_unlock(&usblp->wmut);
791 	return writecount;
792 
793 raise_submit:
794 raise_badaddr:
795 	usb_unanchor_urb(writeurb);
796 	usb_free_urb(writeurb);
797 raise_urb:
798 raise_wait:
799 collect_error:		/* Out of raise sequence */
800 	mutex_unlock(&usblp->wmut);
801 raise_biglock:
802 	return writecount ? writecount : rv;
803 }
804 
805 /*
806  * Notice that we fail to restart in a few cases: on EFAULT, on restart
807  * error, etc. This is the historical behaviour. In all such cases we return
808  * EIO, and applications loop in order to get the new read going.
809  */
810 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
811 {
812 	struct usblp *usblp = file->private_data;
813 	ssize_t count;
814 	ssize_t avail;
815 	int rv;
816 
817 	if (!usblp->bidir)
818 		return -EINVAL;
819 
820 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
821 	if (rv < 0)
822 		return rv;
823 
824 	if ((avail = usblp->rstatus) < 0) {
825 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
826 		    usblp->minor, (int)avail);
827 		usblp_submit_read(usblp);
828 		count = -EIO;
829 		goto done;
830 	}
831 
832 	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
833 	if (count != 0 &&
834 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
835 		count = -EFAULT;
836 		goto done;
837 	}
838 
839 	if ((usblp->readcount += count) == avail) {
840 		if (usblp_submit_read(usblp) < 0) {
841 			/* We don't want to leak USB return codes into errno. */
842 			if (count == 0)
843 				count = -EIO;
844 			goto done;
845 		}
846 	}
847 
848 done:
849 	mutex_unlock(&usblp->mut);
850 	return count;
851 }
852 
853 /*
854  * Wait for the write path to come idle.
855  * This is called under the ->wmut, so the idle path stays idle.
856  *
857  * Our write path has a peculiar property: it does not buffer like a tty,
858  * but waits for the write to succeed. This allows our ->release to bug out
859  * without waiting for writes to drain. But it obviously does not work
860  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
861  * select(2) or poll(2) to wait for the buffer to drain before closing.
862  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
863  */
864 static int usblp_wwait(struct usblp *usblp, int nonblock)
865 {
866 	DECLARE_WAITQUEUE(waita, current);
867 	int rc;
868 	int err = 0;
869 
870 	add_wait_queue(&usblp->wwait, &waita);
871 	for (;;) {
872 		if (mutex_lock_interruptible(&usblp->mut)) {
873 			rc = -EINTR;
874 			break;
875 		}
876 		set_current_state(TASK_INTERRUPTIBLE);
877 		rc = usblp_wtest(usblp, nonblock);
878 		mutex_unlock(&usblp->mut);
879 		if (rc <= 0)
880 			break;
881 
882 		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
883 			if (usblp->flags & LP_ABORT) {
884 				err = usblp_check_status(usblp, err);
885 				if (err == 1) {	/* Paper out */
886 					rc = -ENOSPC;
887 					break;
888 				}
889 			} else {
890 				/* Prod the printer, Gentoo#251237. */
891 				mutex_lock(&usblp->mut);
892 				usblp_read_status(usblp, usblp->statusbuf);
893 				mutex_unlock(&usblp->mut);
894 			}
895 		}
896 	}
897 	set_current_state(TASK_RUNNING);
898 	remove_wait_queue(&usblp->wwait, &waita);
899 	return rc;
900 }
901 
902 static int usblp_wtest(struct usblp *usblp, int nonblock)
903 {
904 	unsigned long flags;
905 
906 	if (!usblp->present)
907 		return -ENODEV;
908 	if (signal_pending(current))
909 		return -EINTR;
910 	spin_lock_irqsave(&usblp->lock, flags);
911 	if (usblp->wcomplete) {
912 		spin_unlock_irqrestore(&usblp->lock, flags);
913 		return 0;
914 	}
915 	spin_unlock_irqrestore(&usblp->lock, flags);
916 	if (nonblock)
917 		return -EAGAIN;
918 	return 1;
919 }
920 
921 /*
922  * Wait for read bytes to become available. This probably should have been
923  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
924  * name for functions which lock and return.
925  *
926  * We do not use wait_event_interruptible because it makes locking iffy.
927  */
928 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
929 {
930 	DECLARE_WAITQUEUE(waita, current);
931 	int rc;
932 
933 	add_wait_queue(&usblp->rwait, &waita);
934 	for (;;) {
935 		if (mutex_lock_interruptible(&usblp->mut)) {
936 			rc = -EINTR;
937 			break;
938 		}
939 		set_current_state(TASK_INTERRUPTIBLE);
940 		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
941 			mutex_unlock(&usblp->mut);
942 			break;
943 		}
944 		if (rc == 0)	/* Keep it locked */
945 			break;
946 		mutex_unlock(&usblp->mut);
947 		schedule();
948 	}
949 	set_current_state(TASK_RUNNING);
950 	remove_wait_queue(&usblp->rwait, &waita);
951 	return rc;
952 }
953 
954 static int usblp_rtest(struct usblp *usblp, int nonblock)
955 {
956 	unsigned long flags;
957 
958 	if (!usblp->present)
959 		return -ENODEV;
960 	if (signal_pending(current))
961 		return -EINTR;
962 	spin_lock_irqsave(&usblp->lock, flags);
963 	if (usblp->rcomplete) {
964 		spin_unlock_irqrestore(&usblp->lock, flags);
965 		return 0;
966 	}
967 	spin_unlock_irqrestore(&usblp->lock, flags);
968 	if (nonblock)
969 		return -EAGAIN;
970 	return 1;
971 }
972 
973 /*
974  * Please check ->bidir and other such things outside for now.
975  */
976 static int usblp_submit_read(struct usblp *usblp)
977 {
978 	struct urb *urb;
979 	unsigned long flags;
980 	int rc;
981 
982 	rc = -ENOMEM;
983 	urb = usb_alloc_urb(0, GFP_KERNEL);
984 	if (urb == NULL)
985 		goto raise_urb;
986 
987 	usb_fill_bulk_urb(urb, usblp->dev,
988 		usb_rcvbulkpipe(usblp->dev,
989 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
990 		usblp->readbuf, USBLP_BUF_SIZE_IN,
991 		usblp_bulk_read, usblp);
992 	usb_anchor_urb(urb, &usblp->urbs);
993 
994 	spin_lock_irqsave(&usblp->lock, flags);
995 	usblp->readcount = 0; /* XXX Why here? */
996 	usblp->rcomplete = 0;
997 	spin_unlock_irqrestore(&usblp->lock, flags);
998 	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
999 		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1000 		spin_lock_irqsave(&usblp->lock, flags);
1001 		usblp->rstatus = rc;
1002 		usblp->rcomplete = 1;
1003 		spin_unlock_irqrestore(&usblp->lock, flags);
1004 		goto raise_submit;
1005 	}
1006 
1007 	return 0;
1008 
1009 raise_submit:
1010 	usb_unanchor_urb(urb);
1011 	usb_free_urb(urb);
1012 raise_urb:
1013 	return rc;
1014 }
1015 
1016 /*
1017  * Checks for printers that have quirks, such as requiring unidirectional
1018  * communication but reporting bidirectional; currently some HP printers
1019  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1020  * sent at each open (like some Epsons).
1021  * Returns 1 if found, 0 if not found.
1022  *
1023  * HP recommended that we use the bidirectional interface but
1024  * don't attempt any bulk IN transfers from the IN endpoint.
1025  * Here's some more detail on the problem:
1026  * The problem is not that it isn't bidirectional though. The problem
1027  * is that if you request a device ID, or status information, while
1028  * the buffers are full, the return data will end up in the print data
1029  * buffer. For example if you make sure you never request the device ID
1030  * while you are sending print data, and you don't try to query the
1031  * printer status every couple of milliseconds, you will probably be OK.
1032  */
1033 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1034 {
1035 	int i;
1036 
1037 	for (i = 0; quirk_printers[i].vendorId; i++) {
1038 		if (vendor == quirk_printers[i].vendorId &&
1039 		    product == quirk_printers[i].productId)
1040 			return quirk_printers[i].quirks;
1041 	}
1042 	return 0;
1043 }
1044 
1045 static const struct file_operations usblp_fops = {
1046 	.owner =	THIS_MODULE,
1047 	.read =		usblp_read,
1048 	.write =	usblp_write,
1049 	.poll =		usblp_poll,
1050 	.unlocked_ioctl =	usblp_ioctl,
1051 	.compat_ioctl =		usblp_ioctl,
1052 	.open =		usblp_open,
1053 	.release =	usblp_release,
1054 	.llseek =	noop_llseek,
1055 };
1056 
1057 static char *usblp_devnode(struct device *dev, umode_t *mode)
1058 {
1059 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1060 }
1061 
1062 static struct usb_class_driver usblp_class = {
1063 	.name =		"lp%d",
1064 	.devnode =	usblp_devnode,
1065 	.fops =		&usblp_fops,
1066 	.minor_base =	USBLP_MINOR_BASE,
1067 };
1068 
1069 static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1070 {
1071 	struct usb_interface *intf = to_usb_interface(dev);
1072 	struct usblp *usblp = usb_get_intfdata(intf);
1073 
1074 	if (usblp->device_id_string[0] == 0 &&
1075 	    usblp->device_id_string[1] == 0)
1076 		return 0;
1077 
1078 	return sprintf(buf, "%s", usblp->device_id_string+2);
1079 }
1080 
1081 static DEVICE_ATTR_RO(ieee1284_id);
1082 
1083 static int usblp_probe(struct usb_interface *intf,
1084 		       const struct usb_device_id *id)
1085 {
1086 	struct usb_device *dev = interface_to_usbdev(intf);
1087 	struct usblp *usblp;
1088 	int protocol;
1089 	int retval;
1090 
1091 	/* Malloc and start initializing usblp structure so we can use it
1092 	 * directly. */
1093 	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1094 	if (!usblp) {
1095 		retval = -ENOMEM;
1096 		goto abort_ret;
1097 	}
1098 	usblp->dev = dev;
1099 	mutex_init(&usblp->wmut);
1100 	mutex_init(&usblp->mut);
1101 	spin_lock_init(&usblp->lock);
1102 	init_waitqueue_head(&usblp->rwait);
1103 	init_waitqueue_head(&usblp->wwait);
1104 	init_usb_anchor(&usblp->urbs);
1105 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1106 	usblp->intf = intf;
1107 
1108 	/* Malloc device ID string buffer to the largest expected length,
1109 	 * since we can re-query it on an ioctl and a dynamic string
1110 	 * could change in length. */
1111 	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1112 		retval = -ENOMEM;
1113 		goto abort;
1114 	}
1115 
1116 	/*
1117 	 * Allocate read buffer. We somewhat wastefully
1118 	 * malloc both regardless of bidirectionality, because the
1119 	 * alternate setting can be changed later via an ioctl.
1120 	 */
1121 	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1122 		retval = -ENOMEM;
1123 		goto abort;
1124 	}
1125 
1126 	/* Allocate buffer for printer status */
1127 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1128 	if (!usblp->statusbuf) {
1129 		retval = -ENOMEM;
1130 		goto abort;
1131 	}
1132 
1133 	/* Lookup quirks for this printer. */
1134 	usblp->quirks = usblp_quirks(
1135 		le16_to_cpu(dev->descriptor.idVendor),
1136 		le16_to_cpu(dev->descriptor.idProduct));
1137 
1138 	/* Analyze and pick initial alternate settings and endpoints. */
1139 	protocol = usblp_select_alts(usblp);
1140 	if (protocol < 0) {
1141 		dev_dbg(&intf->dev,
1142 			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1143 			le16_to_cpu(dev->descriptor.idVendor),
1144 			le16_to_cpu(dev->descriptor.idProduct));
1145 		retval = -ENODEV;
1146 		goto abort;
1147 	}
1148 
1149 	/* Setup the selected alternate setting and endpoints. */
1150 	if (usblp_set_protocol(usblp, protocol) < 0) {
1151 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1152 		goto abort;
1153 	}
1154 
1155 	/* Retrieve and store the device ID string. */
1156 	usblp_cache_device_id_string(usblp);
1157 	retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1158 	if (retval)
1159 		goto abort_intfdata;
1160 
1161 #ifdef DEBUG
1162 	usblp_check_status(usblp, 0);
1163 #endif
1164 
1165 	usb_set_intfdata(intf, usblp);
1166 
1167 	usblp->present = 1;
1168 
1169 	retval = usb_register_dev(intf, &usblp_class);
1170 	if (retval) {
1171 		dev_err(&intf->dev,
1172 			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1173 			USBLP_MINOR_BASE, retval);
1174 		goto abort_intfdata;
1175 	}
1176 	usblp->minor = intf->minor;
1177 	dev_info(&intf->dev,
1178 		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1179 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1180 		usblp->ifnum,
1181 		usblp->protocol[usblp->current_protocol].alt_setting,
1182 		usblp->current_protocol,
1183 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1184 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1185 
1186 	return 0;
1187 
1188 abort_intfdata:
1189 	usb_set_intfdata(intf, NULL);
1190 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1191 abort:
1192 	kfree(usblp->readbuf);
1193 	kfree(usblp->statusbuf);
1194 	kfree(usblp->device_id_string);
1195 	kfree(usblp);
1196 abort_ret:
1197 	return retval;
1198 }
1199 
1200 /*
1201  * We are a "new" style driver with usb_device_id table,
1202  * but our requirements are too intricate for simple match to handle.
1203  *
1204  * The "proto_bias" option may be used to specify the preferred protocol
1205  * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1206  * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1207  * then we bind to it.
1208  *
1209  * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1210  * is compatible with a stream of characters. If we find it, we bind to it.
1211  *
1212  * Note that the people from hpoj.sourceforge.net need to be able to
1213  * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1214  * for this purpose.
1215  *
1216  * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1217  * even though it's probably not stream-compatible, because this matches
1218  * the behaviour of the old code.
1219  *
1220  * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1221  * - the unidirectional interface.
1222  */
1223 static int usblp_select_alts(struct usblp *usblp)
1224 {
1225 	struct usb_interface *if_alt;
1226 	struct usb_host_interface *ifd;
1227 	struct usb_endpoint_descriptor *epwrite, *epread;
1228 	int p, i;
1229 	int res;
1230 
1231 	if_alt = usblp->intf;
1232 
1233 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1234 		usblp->protocol[p].alt_setting = -1;
1235 
1236 	/* Find out what we have. */
1237 	for (i = 0; i < if_alt->num_altsetting; i++) {
1238 		ifd = &if_alt->altsetting[i];
1239 
1240 		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1241 		    ifd->desc.bInterfaceSubClass != 1)
1242 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1243 				continue;
1244 
1245 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1246 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1247 			continue;
1248 
1249 		/* Look for the expected bulk endpoints. */
1250 		if (ifd->desc.bInterfaceProtocol > 1) {
1251 			res = usb_find_common_endpoints(ifd,
1252 					&epread, &epwrite, NULL, NULL);
1253 		} else {
1254 			epread = NULL;
1255 			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1256 		}
1257 
1258 		/* Ignore buggy hardware without the right endpoints. */
1259 		if (res)
1260 			continue;
1261 
1262 		/* Turn off reads for buggy bidirectional printers. */
1263 		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1264 			printk(KERN_INFO "usblp%d: Disabling reads from "
1265 			    "problematic bidirectional printer\n",
1266 			    usblp->minor);
1267 			epread = NULL;
1268 		}
1269 
1270 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1271 				ifd->desc.bAlternateSetting;
1272 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1273 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1274 	}
1275 
1276 	/* If our requested protocol is supported, then use it. */
1277 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1278 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1279 	    usblp->protocol[proto_bias].alt_setting != -1)
1280 		return proto_bias;
1281 
1282 	/* Ordering is important here. */
1283 	if (usblp->protocol[2].alt_setting != -1)
1284 		return 2;
1285 	if (usblp->protocol[1].alt_setting != -1)
1286 		return 1;
1287 	if (usblp->protocol[3].alt_setting != -1)
1288 		return 3;
1289 
1290 	/* If nothing is available, then don't bind to this device. */
1291 	return -1;
1292 }
1293 
1294 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1295 {
1296 	int r, alts;
1297 
1298 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1299 		return -EINVAL;
1300 
1301 	alts = usblp->protocol[protocol].alt_setting;
1302 	if (alts < 0)
1303 		return -EINVAL;
1304 	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1305 	if (r < 0) {
1306 		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1307 			alts, usblp->ifnum);
1308 		return r;
1309 	}
1310 
1311 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1312 	usblp->current_protocol = protocol;
1313 	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1314 		usblp->minor, protocol);
1315 	return 0;
1316 }
1317 
1318 /* Retrieves and caches device ID string.
1319  * Returns length, including length bytes but not null terminator.
1320  * On error, returns a negative errno value. */
1321 static int usblp_cache_device_id_string(struct usblp *usblp)
1322 {
1323 	int err, length;
1324 
1325 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1326 	if (err < 0) {
1327 		dev_dbg(&usblp->intf->dev,
1328 			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1329 			usblp->minor, err);
1330 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1331 		return -EIO;
1332 	}
1333 
1334 	/* First two bytes are length in big-endian.
1335 	 * They count themselves, and we copy them into
1336 	 * the user's buffer. */
1337 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1338 	if (length < 2)
1339 		length = 2;
1340 	else if (length >= USBLP_DEVICE_ID_SIZE)
1341 		length = USBLP_DEVICE_ID_SIZE - 1;
1342 	usblp->device_id_string[length] = '\0';
1343 
1344 	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1345 		usblp->minor, length, &usblp->device_id_string[2]);
1346 
1347 	return length;
1348 }
1349 
1350 static void usblp_disconnect(struct usb_interface *intf)
1351 {
1352 	struct usblp *usblp = usb_get_intfdata(intf);
1353 
1354 	usb_deregister_dev(intf, &usblp_class);
1355 
1356 	if (!usblp || !usblp->dev) {
1357 		dev_err(&intf->dev, "bogus disconnect\n");
1358 		BUG();
1359 	}
1360 
1361 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1362 
1363 	mutex_lock(&usblp_mutex);
1364 	mutex_lock(&usblp->mut);
1365 	usblp->present = 0;
1366 	wake_up(&usblp->wwait);
1367 	wake_up(&usblp->rwait);
1368 	usb_set_intfdata(intf, NULL);
1369 
1370 	usblp_unlink_urbs(usblp);
1371 	mutex_unlock(&usblp->mut);
1372 
1373 	if (!usblp->used)
1374 		usblp_cleanup(usblp);
1375 	mutex_unlock(&usblp_mutex);
1376 }
1377 
1378 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1379 {
1380 	struct usblp *usblp = usb_get_intfdata(intf);
1381 
1382 	usblp_unlink_urbs(usblp);
1383 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1384 	/* not strictly necessary, but just in case */
1385 	wake_up(&usblp->wwait);
1386 	wake_up(&usblp->rwait);
1387 #endif
1388 
1389 	return 0;
1390 }
1391 
1392 static int usblp_resume(struct usb_interface *intf)
1393 {
1394 	struct usblp *usblp = usb_get_intfdata(intf);
1395 	int r;
1396 
1397 	r = handle_bidir(usblp);
1398 
1399 	return r;
1400 }
1401 
1402 static const struct usb_device_id usblp_ids[] = {
1403 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1404 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1405 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1406 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1407 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1408 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1409 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1410 	{ }						/* Terminating entry */
1411 };
1412 
1413 MODULE_DEVICE_TABLE(usb, usblp_ids);
1414 
1415 static struct usb_driver usblp_driver = {
1416 	.name =		"usblp",
1417 	.probe =	usblp_probe,
1418 	.disconnect =	usblp_disconnect,
1419 	.suspend =	usblp_suspend,
1420 	.resume =	usblp_resume,
1421 	.id_table =	usblp_ids,
1422 	.supports_autosuspend =	1,
1423 };
1424 
1425 module_usb_driver(usblp_driver);
1426 
1427 MODULE_AUTHOR(DRIVER_AUTHOR);
1428 MODULE_DESCRIPTION(DRIVER_DESC);
1429 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1430 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1431 MODULE_LICENSE("GPL");
1432