xref: /openbmc/linux/drivers/usb/class/usblp.c (revision e15a5365)
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 	unsigned long flags;
296 
297 	if (usblp->present && usblp->used) {
298 		if (status)
299 			printk(KERN_WARNING "usblp%d: "
300 			    "nonzero read bulk status received: %d\n",
301 			    usblp->minor, status);
302 	}
303 	spin_lock_irqsave(&usblp->lock, flags);
304 	if (status < 0)
305 		usblp->rstatus = status;
306 	else
307 		usblp->rstatus = urb->actual_length;
308 	usblp->rcomplete = 1;
309 	wake_up(&usblp->rwait);
310 	spin_unlock_irqrestore(&usblp->lock, flags);
311 
312 	usb_free_urb(urb);
313 }
314 
315 static void usblp_bulk_write(struct urb *urb)
316 {
317 	struct usblp *usblp = urb->context;
318 	int status = urb->status;
319 	unsigned long flags;
320 
321 	if (usblp->present && usblp->used) {
322 		if (status)
323 			printk(KERN_WARNING "usblp%d: "
324 			    "nonzero write bulk status received: %d\n",
325 			    usblp->minor, status);
326 	}
327 	spin_lock_irqsave(&usblp->lock, flags);
328 	if (status < 0)
329 		usblp->wstatus = status;
330 	else
331 		usblp->wstatus = urb->actual_length;
332 	usblp->no_paper = 0;
333 	usblp->wcomplete = 1;
334 	wake_up(&usblp->wwait);
335 	spin_unlock_irqrestore(&usblp->lock, flags);
336 
337 	usb_free_urb(urb);
338 }
339 
340 /*
341  * Get and print printer errors.
342  */
343 
344 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
345 
346 static int usblp_check_status(struct usblp *usblp, int err)
347 {
348 	unsigned char status, newerr = 0;
349 	int error;
350 
351 	mutex_lock(&usblp->mut);
352 	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
353 		mutex_unlock(&usblp->mut);
354 		printk_ratelimited(KERN_ERR
355 				"usblp%d: error %d reading printer status\n",
356 				usblp->minor, error);
357 		return 0;
358 	}
359 	status = *usblp->statusbuf;
360 	mutex_unlock(&usblp->mut);
361 
362 	if (~status & LP_PERRORP)
363 		newerr = 3;
364 	if (status & LP_POUTPA)
365 		newerr = 1;
366 	if (~status & LP_PSELECD)
367 		newerr = 2;
368 
369 	if (newerr != err) {
370 		printk(KERN_INFO "usblp%d: %s\n",
371 		   usblp->minor, usblp_messages[newerr]);
372 	}
373 
374 	return newerr;
375 }
376 
377 static int handle_bidir(struct usblp *usblp)
378 {
379 	if (usblp->bidir && usblp->used) {
380 		if (usblp_submit_read(usblp) < 0)
381 			return -EIO;
382 	}
383 	return 0;
384 }
385 
386 /*
387  * File op functions.
388  */
389 
390 static int usblp_open(struct inode *inode, struct file *file)
391 {
392 	int minor = iminor(inode);
393 	struct usblp *usblp;
394 	struct usb_interface *intf;
395 	int retval;
396 
397 	if (minor < 0)
398 		return -ENODEV;
399 
400 	mutex_lock(&usblp_mutex);
401 
402 	retval = -ENODEV;
403 	intf = usb_find_interface(&usblp_driver, minor);
404 	if (!intf)
405 		goto out;
406 	usblp = usb_get_intfdata(intf);
407 	if (!usblp || !usblp->dev || !usblp->present)
408 		goto out;
409 
410 	retval = -EBUSY;
411 	if (usblp->used)
412 		goto out;
413 
414 	/*
415 	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
416 	 *  - We do not want persistent state which close(2) does not clear
417 	 *  - It is not used anyway, according to CUPS people
418 	 */
419 
420 	retval = usb_autopm_get_interface(intf);
421 	if (retval < 0)
422 		goto out;
423 	usblp->used = 1;
424 	file->private_data = usblp;
425 
426 	usblp->wcomplete = 1; /* we begin writeable */
427 	usblp->wstatus = 0;
428 	usblp->rcomplete = 0;
429 
430 	if (handle_bidir(usblp) < 0) {
431 		usb_autopm_put_interface(intf);
432 		usblp->used = 0;
433 		file->private_data = NULL;
434 		retval = -EIO;
435 	}
436 out:
437 	mutex_unlock(&usblp_mutex);
438 	return retval;
439 }
440 
441 static void usblp_cleanup(struct usblp *usblp)
442 {
443 	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
444 
445 	kfree(usblp->readbuf);
446 	kfree(usblp->device_id_string);
447 	kfree(usblp->statusbuf);
448 	usb_put_intf(usblp->intf);
449 	kfree(usblp);
450 }
451 
452 static void usblp_unlink_urbs(struct usblp *usblp)
453 {
454 	usb_kill_anchored_urbs(&usblp->urbs);
455 }
456 
457 static int usblp_release(struct inode *inode, struct file *file)
458 {
459 	struct usblp *usblp = file->private_data;
460 
461 	usblp->flags &= ~LP_ABORT;
462 
463 	mutex_lock(&usblp_mutex);
464 	usblp->used = 0;
465 	if (usblp->present)
466 		usblp_unlink_urbs(usblp);
467 
468 	usb_autopm_put_interface(usblp->intf);
469 
470 	if (!usblp->present)		/* finish cleanup from disconnect */
471 		usblp_cleanup(usblp);	/* any URBs must be dead */
472 
473 	mutex_unlock(&usblp_mutex);
474 	return 0;
475 }
476 
477 /* No kernel lock - fine */
478 static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
479 {
480 	__poll_t ret;
481 	unsigned long flags;
482 
483 	struct usblp *usblp = file->private_data;
484 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
485 	poll_wait(file, &usblp->rwait, wait);
486 	poll_wait(file, &usblp->wwait, wait);
487 	spin_lock_irqsave(&usblp->lock, flags);
488 	ret = ((usblp->bidir && usblp->rcomplete) ? EPOLLIN  | EPOLLRDNORM : 0) |
489 	   ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 0);
490 	spin_unlock_irqrestore(&usblp->lock, flags);
491 	return ret;
492 }
493 
494 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
495 {
496 	struct usblp *usblp = file->private_data;
497 	int length, err, i;
498 	unsigned char newChannel;
499 	int status;
500 	int twoints[2];
501 	int retval = 0;
502 
503 	mutex_lock(&usblp->mut);
504 	if (!usblp->present) {
505 		retval = -ENODEV;
506 		goto done;
507 	}
508 
509 	dev_dbg(&usblp->intf->dev,
510 		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
511 		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
512 
513 	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
514 
515 		switch (_IOC_NR(cmd)) {
516 
517 		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
518 			if (_IOC_DIR(cmd) != _IOC_READ) {
519 				retval = -EINVAL;
520 				goto done;
521 			}
522 
523 			length = usblp_cache_device_id_string(usblp);
524 			if (length < 0) {
525 				retval = length;
526 				goto done;
527 			}
528 			if (length > _IOC_SIZE(cmd))
529 				length = _IOC_SIZE(cmd); /* truncate */
530 
531 			if (copy_to_user((void __user *) arg,
532 					usblp->device_id_string,
533 					(unsigned long) length)) {
534 				retval = -EFAULT;
535 				goto done;
536 			}
537 
538 			break;
539 
540 		case IOCNR_GET_PROTOCOLS:
541 			if (_IOC_DIR(cmd) != _IOC_READ ||
542 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
543 				retval = -EINVAL;
544 				goto done;
545 			}
546 
547 			twoints[0] = usblp->current_protocol;
548 			twoints[1] = 0;
549 			for (i = USBLP_FIRST_PROTOCOL;
550 			     i <= USBLP_LAST_PROTOCOL; i++) {
551 				if (usblp->protocol[i].alt_setting >= 0)
552 					twoints[1] |= (1<<i);
553 			}
554 
555 			if (copy_to_user((void __user *)arg,
556 					(unsigned char *)twoints,
557 					sizeof(twoints))) {
558 				retval = -EFAULT;
559 				goto done;
560 			}
561 
562 			break;
563 
564 		case IOCNR_SET_PROTOCOL:
565 			if (_IOC_DIR(cmd) != _IOC_WRITE) {
566 				retval = -EINVAL;
567 				goto done;
568 			}
569 
570 #ifdef DEBUG
571 			if (arg == -10) {
572 				usblp_dump(usblp);
573 				break;
574 			}
575 #endif
576 
577 			usblp_unlink_urbs(usblp);
578 			retval = usblp_set_protocol(usblp, arg);
579 			if (retval < 0) {
580 				usblp_set_protocol(usblp,
581 					usblp->current_protocol);
582 			}
583 			break;
584 
585 		case IOCNR_HP_SET_CHANNEL:
586 			if (_IOC_DIR(cmd) != _IOC_WRITE ||
587 			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
588 			    usblp->quirks & USBLP_QUIRK_BIDIR) {
589 				retval = -EINVAL;
590 				goto done;
591 			}
592 
593 			err = usblp_hp_channel_change_request(usblp,
594 				arg, &newChannel);
595 			if (err < 0) {
596 				dev_err(&usblp->dev->dev,
597 					"usblp%d: error = %d setting "
598 					"HP channel\n",
599 					usblp->minor, err);
600 				retval = -EIO;
601 				goto done;
602 			}
603 
604 			dev_dbg(&usblp->intf->dev,
605 				"usblp%d requested/got HP channel %ld/%d\n",
606 				usblp->minor, arg, newChannel);
607 			break;
608 
609 		case IOCNR_GET_BUS_ADDRESS:
610 			if (_IOC_DIR(cmd) != _IOC_READ ||
611 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
612 				retval = -EINVAL;
613 				goto done;
614 			}
615 
616 			twoints[0] = usblp->dev->bus->busnum;
617 			twoints[1] = usblp->dev->devnum;
618 			if (copy_to_user((void __user *)arg,
619 					(unsigned char *)twoints,
620 					sizeof(twoints))) {
621 				retval = -EFAULT;
622 				goto done;
623 			}
624 
625 			dev_dbg(&usblp->intf->dev,
626 				"usblp%d is bus=%d, device=%d\n",
627 				usblp->minor, twoints[0], twoints[1]);
628 			break;
629 
630 		case IOCNR_GET_VID_PID:
631 			if (_IOC_DIR(cmd) != _IOC_READ ||
632 			    _IOC_SIZE(cmd) < sizeof(twoints)) {
633 				retval = -EINVAL;
634 				goto done;
635 			}
636 
637 			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
638 			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
639 			if (copy_to_user((void __user *)arg,
640 					(unsigned char *)twoints,
641 					sizeof(twoints))) {
642 				retval = -EFAULT;
643 				goto done;
644 			}
645 
646 			dev_dbg(&usblp->intf->dev,
647 				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
648 				usblp->minor, twoints[0], twoints[1]);
649 			break;
650 
651 		case IOCNR_SOFT_RESET:
652 			if (_IOC_DIR(cmd) != _IOC_NONE) {
653 				retval = -EINVAL;
654 				goto done;
655 			}
656 			retval = usblp_reset(usblp);
657 			break;
658 		default:
659 			retval = -ENOTTY;
660 		}
661 	else	/* old-style ioctl value */
662 		switch (cmd) {
663 
664 		case LPGETSTATUS:
665 			retval = usblp_read_status(usblp, usblp->statusbuf);
666 			if (retval) {
667 				printk_ratelimited(KERN_ERR "usblp%d:"
668 					    "failed reading printer status (%d)\n",
669 					    usblp->minor, retval);
670 				retval = -EIO;
671 				goto done;
672 			}
673 			status = *usblp->statusbuf;
674 			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
675 				retval = -EFAULT;
676 			break;
677 
678 		case LPABORT:
679 			if (arg)
680 				usblp->flags |= LP_ABORT;
681 			else
682 				usblp->flags &= ~LP_ABORT;
683 			break;
684 
685 		default:
686 			retval = -ENOTTY;
687 		}
688 
689 done:
690 	mutex_unlock(&usblp->mut);
691 	return retval;
692 }
693 
694 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
695 {
696 	struct urb *urb;
697 	char *writebuf;
698 
699 	writebuf = kmalloc(transfer_length, GFP_KERNEL);
700 	if (writebuf == NULL)
701 		return NULL;
702 	urb = usb_alloc_urb(0, GFP_KERNEL);
703 	if (urb == NULL) {
704 		kfree(writebuf);
705 		return NULL;
706 	}
707 
708 	usb_fill_bulk_urb(urb, usblp->dev,
709 		usb_sndbulkpipe(usblp->dev,
710 		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
711 		writebuf, transfer_length, usblp_bulk_write, usblp);
712 	urb->transfer_flags |= URB_FREE_BUFFER;
713 
714 	return urb;
715 }
716 
717 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
718 {
719 	struct usblp *usblp = file->private_data;
720 	struct urb *writeurb;
721 	int rv;
722 	int transfer_length;
723 	ssize_t writecount = 0;
724 
725 	if (mutex_lock_interruptible(&usblp->wmut)) {
726 		rv = -EINTR;
727 		goto raise_biglock;
728 	}
729 	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
730 		goto raise_wait;
731 
732 	while (writecount < count) {
733 		/*
734 		 * Step 1: Submit next block.
735 		 */
736 		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
737 			transfer_length = USBLP_BUF_SIZE;
738 
739 		rv = -ENOMEM;
740 		writeurb = usblp_new_writeurb(usblp, transfer_length);
741 		if (writeurb == NULL)
742 			goto raise_urb;
743 		usb_anchor_urb(writeurb, &usblp->urbs);
744 
745 		if (copy_from_user(writeurb->transfer_buffer,
746 				   buffer + writecount, transfer_length)) {
747 			rv = -EFAULT;
748 			goto raise_badaddr;
749 		}
750 
751 		spin_lock_irq(&usblp->lock);
752 		usblp->wcomplete = 0;
753 		spin_unlock_irq(&usblp->lock);
754 		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
755 			usblp->wstatus = 0;
756 			spin_lock_irq(&usblp->lock);
757 			usblp->no_paper = 0;
758 			usblp->wcomplete = 1;
759 			wake_up(&usblp->wwait);
760 			spin_unlock_irq(&usblp->lock);
761 			if (rv != -ENOMEM)
762 				rv = -EIO;
763 			goto raise_submit;
764 		}
765 
766 		/*
767 		 * Step 2: Wait for transfer to end, collect results.
768 		 */
769 		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
770 		if (rv < 0) {
771 			if (rv == -EAGAIN) {
772 				/* Presume that it's going to complete well. */
773 				writecount += transfer_length;
774 			}
775 			if (rv == -ENOSPC) {
776 				spin_lock_irq(&usblp->lock);
777 				usblp->no_paper = 1;	/* Mark for poll(2) */
778 				spin_unlock_irq(&usblp->lock);
779 				writecount += transfer_length;
780 			}
781 			/* Leave URB dangling, to be cleaned on close. */
782 			goto collect_error;
783 		}
784 
785 		if (usblp->wstatus < 0) {
786 			rv = -EIO;
787 			goto collect_error;
788 		}
789 		/*
790 		 * This is critical: it must be our URB, not other writer's.
791 		 * The wmut exists mainly to cover us here.
792 		 */
793 		writecount += usblp->wstatus;
794 	}
795 
796 	mutex_unlock(&usblp->wmut);
797 	return writecount;
798 
799 raise_submit:
800 raise_badaddr:
801 	usb_unanchor_urb(writeurb);
802 	usb_free_urb(writeurb);
803 raise_urb:
804 raise_wait:
805 collect_error:		/* Out of raise sequence */
806 	mutex_unlock(&usblp->wmut);
807 raise_biglock:
808 	return writecount ? writecount : rv;
809 }
810 
811 /*
812  * Notice that we fail to restart in a few cases: on EFAULT, on restart
813  * error, etc. This is the historical behaviour. In all such cases we return
814  * EIO, and applications loop in order to get the new read going.
815  */
816 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
817 {
818 	struct usblp *usblp = file->private_data;
819 	ssize_t count;
820 	ssize_t avail;
821 	int rv;
822 
823 	if (!usblp->bidir)
824 		return -EINVAL;
825 
826 	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
827 	if (rv < 0)
828 		return rv;
829 
830 	if (!usblp->present) {
831 		count = -ENODEV;
832 		goto done;
833 	}
834 
835 	if ((avail = usblp->rstatus) < 0) {
836 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
837 		    usblp->minor, (int)avail);
838 		usblp_submit_read(usblp);
839 		count = -EIO;
840 		goto done;
841 	}
842 
843 	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
844 	if (count != 0 &&
845 	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
846 		count = -EFAULT;
847 		goto done;
848 	}
849 
850 	if ((usblp->readcount += count) == avail) {
851 		if (usblp_submit_read(usblp) < 0) {
852 			/* We don't want to leak USB return codes into errno. */
853 			if (count == 0)
854 				count = -EIO;
855 			goto done;
856 		}
857 	}
858 
859 done:
860 	mutex_unlock(&usblp->mut);
861 	return count;
862 }
863 
864 /*
865  * Wait for the write path to come idle.
866  * This is called under the ->wmut, so the idle path stays idle.
867  *
868  * Our write path has a peculiar property: it does not buffer like a tty,
869  * but waits for the write to succeed. This allows our ->release to bug out
870  * without waiting for writes to drain. But it obviously does not work
871  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
872  * select(2) or poll(2) to wait for the buffer to drain before closing.
873  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
874  */
875 static int usblp_wwait(struct usblp *usblp, int nonblock)
876 {
877 	DECLARE_WAITQUEUE(waita, current);
878 	int rc;
879 	int err = 0;
880 
881 	add_wait_queue(&usblp->wwait, &waita);
882 	for (;;) {
883 		if (mutex_lock_interruptible(&usblp->mut)) {
884 			rc = -EINTR;
885 			break;
886 		}
887 		set_current_state(TASK_INTERRUPTIBLE);
888 		rc = usblp_wtest(usblp, nonblock);
889 		mutex_unlock(&usblp->mut);
890 		if (rc <= 0)
891 			break;
892 
893 		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
894 			if (usblp->flags & LP_ABORT) {
895 				err = usblp_check_status(usblp, err);
896 				if (err == 1) {	/* Paper out */
897 					rc = -ENOSPC;
898 					break;
899 				}
900 			} else {
901 				/* Prod the printer, Gentoo#251237. */
902 				mutex_lock(&usblp->mut);
903 				usblp_read_status(usblp, usblp->statusbuf);
904 				mutex_unlock(&usblp->mut);
905 			}
906 		}
907 	}
908 	set_current_state(TASK_RUNNING);
909 	remove_wait_queue(&usblp->wwait, &waita);
910 	return rc;
911 }
912 
913 static int usblp_wtest(struct usblp *usblp, int nonblock)
914 {
915 	unsigned long flags;
916 
917 	if (!usblp->present)
918 		return -ENODEV;
919 	if (signal_pending(current))
920 		return -EINTR;
921 	spin_lock_irqsave(&usblp->lock, flags);
922 	if (usblp->wcomplete) {
923 		spin_unlock_irqrestore(&usblp->lock, flags);
924 		return 0;
925 	}
926 	spin_unlock_irqrestore(&usblp->lock, flags);
927 	if (nonblock)
928 		return -EAGAIN;
929 	return 1;
930 }
931 
932 /*
933  * Wait for read bytes to become available. This probably should have been
934  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
935  * name for functions which lock and return.
936  *
937  * We do not use wait_event_interruptible because it makes locking iffy.
938  */
939 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
940 {
941 	DECLARE_WAITQUEUE(waita, current);
942 	int rc;
943 
944 	add_wait_queue(&usblp->rwait, &waita);
945 	for (;;) {
946 		if (mutex_lock_interruptible(&usblp->mut)) {
947 			rc = -EINTR;
948 			break;
949 		}
950 		set_current_state(TASK_INTERRUPTIBLE);
951 		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
952 			mutex_unlock(&usblp->mut);
953 			break;
954 		}
955 		if (rc == 0)	/* Keep it locked */
956 			break;
957 		mutex_unlock(&usblp->mut);
958 		schedule();
959 	}
960 	set_current_state(TASK_RUNNING);
961 	remove_wait_queue(&usblp->rwait, &waita);
962 	return rc;
963 }
964 
965 static int usblp_rtest(struct usblp *usblp, int nonblock)
966 {
967 	unsigned long flags;
968 
969 	if (!usblp->present)
970 		return -ENODEV;
971 	if (signal_pending(current))
972 		return -EINTR;
973 	spin_lock_irqsave(&usblp->lock, flags);
974 	if (usblp->rcomplete) {
975 		spin_unlock_irqrestore(&usblp->lock, flags);
976 		return 0;
977 	}
978 	spin_unlock_irqrestore(&usblp->lock, flags);
979 	if (nonblock)
980 		return -EAGAIN;
981 	return 1;
982 }
983 
984 /*
985  * Please check ->bidir and other such things outside for now.
986  */
987 static int usblp_submit_read(struct usblp *usblp)
988 {
989 	struct urb *urb;
990 	unsigned long flags;
991 	int rc;
992 
993 	rc = -ENOMEM;
994 	urb = usb_alloc_urb(0, GFP_KERNEL);
995 	if (urb == NULL)
996 		goto raise_urb;
997 
998 	usb_fill_bulk_urb(urb, usblp->dev,
999 		usb_rcvbulkpipe(usblp->dev,
1000 		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
1001 		usblp->readbuf, USBLP_BUF_SIZE_IN,
1002 		usblp_bulk_read, usblp);
1003 	usb_anchor_urb(urb, &usblp->urbs);
1004 
1005 	spin_lock_irqsave(&usblp->lock, flags);
1006 	usblp->readcount = 0; /* XXX Why here? */
1007 	usblp->rcomplete = 0;
1008 	spin_unlock_irqrestore(&usblp->lock, flags);
1009 	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1010 		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1011 		spin_lock_irqsave(&usblp->lock, flags);
1012 		usblp->rstatus = rc;
1013 		usblp->rcomplete = 1;
1014 		spin_unlock_irqrestore(&usblp->lock, flags);
1015 		goto raise_submit;
1016 	}
1017 
1018 	return 0;
1019 
1020 raise_submit:
1021 	usb_unanchor_urb(urb);
1022 	usb_free_urb(urb);
1023 raise_urb:
1024 	return rc;
1025 }
1026 
1027 /*
1028  * Checks for printers that have quirks, such as requiring unidirectional
1029  * communication but reporting bidirectional; currently some HP printers
1030  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1031  * sent at each open (like some Epsons).
1032  * Returns 1 if found, 0 if not found.
1033  *
1034  * HP recommended that we use the bidirectional interface but
1035  * don't attempt any bulk IN transfers from the IN endpoint.
1036  * Here's some more detail on the problem:
1037  * The problem is not that it isn't bidirectional though. The problem
1038  * is that if you request a device ID, or status information, while
1039  * the buffers are full, the return data will end up in the print data
1040  * buffer. For example if you make sure you never request the device ID
1041  * while you are sending print data, and you don't try to query the
1042  * printer status every couple of milliseconds, you will probably be OK.
1043  */
1044 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1045 {
1046 	int i;
1047 
1048 	for (i = 0; quirk_printers[i].vendorId; i++) {
1049 		if (vendor == quirk_printers[i].vendorId &&
1050 		    product == quirk_printers[i].productId)
1051 			return quirk_printers[i].quirks;
1052 	}
1053 	return 0;
1054 }
1055 
1056 static const struct file_operations usblp_fops = {
1057 	.owner =	THIS_MODULE,
1058 	.read =		usblp_read,
1059 	.write =	usblp_write,
1060 	.poll =		usblp_poll,
1061 	.unlocked_ioctl =	usblp_ioctl,
1062 	.compat_ioctl =		usblp_ioctl,
1063 	.open =		usblp_open,
1064 	.release =	usblp_release,
1065 	.llseek =	noop_llseek,
1066 };
1067 
1068 static char *usblp_devnode(struct device *dev, umode_t *mode)
1069 {
1070 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1071 }
1072 
1073 static struct usb_class_driver usblp_class = {
1074 	.name =		"lp%d",
1075 	.devnode =	usblp_devnode,
1076 	.fops =		&usblp_fops,
1077 	.minor_base =	USBLP_MINOR_BASE,
1078 };
1079 
1080 static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
1081 {
1082 	struct usb_interface *intf = to_usb_interface(dev);
1083 	struct usblp *usblp = usb_get_intfdata(intf);
1084 
1085 	if (usblp->device_id_string[0] == 0 &&
1086 	    usblp->device_id_string[1] == 0)
1087 		return 0;
1088 
1089 	return sprintf(buf, "%s", usblp->device_id_string+2);
1090 }
1091 
1092 static DEVICE_ATTR_RO(ieee1284_id);
1093 
1094 static struct attribute *usblp_attrs[] = {
1095 	&dev_attr_ieee1284_id.attr,
1096 	NULL,
1097 };
1098 ATTRIBUTE_GROUPS(usblp);
1099 
1100 static int usblp_probe(struct usb_interface *intf,
1101 		       const struct usb_device_id *id)
1102 {
1103 	struct usb_device *dev = interface_to_usbdev(intf);
1104 	struct usblp *usblp;
1105 	int protocol;
1106 	int retval;
1107 
1108 	/* Malloc and start initializing usblp structure so we can use it
1109 	 * directly. */
1110 	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1111 	if (!usblp) {
1112 		retval = -ENOMEM;
1113 		goto abort_ret;
1114 	}
1115 	usblp->dev = dev;
1116 	mutex_init(&usblp->wmut);
1117 	mutex_init(&usblp->mut);
1118 	spin_lock_init(&usblp->lock);
1119 	init_waitqueue_head(&usblp->rwait);
1120 	init_waitqueue_head(&usblp->wwait);
1121 	init_usb_anchor(&usblp->urbs);
1122 	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1123 	usblp->intf = usb_get_intf(intf);
1124 
1125 	/* Malloc device ID string buffer to the largest expected length,
1126 	 * since we can re-query it on an ioctl and a dynamic string
1127 	 * could change in length. */
1128 	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1129 		retval = -ENOMEM;
1130 		goto abort;
1131 	}
1132 
1133 	/*
1134 	 * Allocate read buffer. We somewhat wastefully
1135 	 * malloc both regardless of bidirectionality, because the
1136 	 * alternate setting can be changed later via an ioctl.
1137 	 */
1138 	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1139 		retval = -ENOMEM;
1140 		goto abort;
1141 	}
1142 
1143 	/* Allocate buffer for printer status */
1144 	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1145 	if (!usblp->statusbuf) {
1146 		retval = -ENOMEM;
1147 		goto abort;
1148 	}
1149 
1150 	/* Lookup quirks for this printer. */
1151 	usblp->quirks = usblp_quirks(
1152 		le16_to_cpu(dev->descriptor.idVendor),
1153 		le16_to_cpu(dev->descriptor.idProduct));
1154 
1155 	/* Analyze and pick initial alternate settings and endpoints. */
1156 	protocol = usblp_select_alts(usblp);
1157 	if (protocol < 0) {
1158 		dev_dbg(&intf->dev,
1159 			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1160 			le16_to_cpu(dev->descriptor.idVendor),
1161 			le16_to_cpu(dev->descriptor.idProduct));
1162 		retval = -ENODEV;
1163 		goto abort;
1164 	}
1165 
1166 	/* Setup the selected alternate setting and endpoints. */
1167 	if (usblp_set_protocol(usblp, protocol) < 0) {
1168 		retval = -ENODEV;	/* ->probe isn't ->ioctl */
1169 		goto abort;
1170 	}
1171 
1172 	/* Retrieve and store the device ID string. */
1173 	usblp_cache_device_id_string(usblp);
1174 
1175 #ifdef DEBUG
1176 	usblp_check_status(usblp, 0);
1177 #endif
1178 
1179 	usb_set_intfdata(intf, usblp);
1180 
1181 	usblp->present = 1;
1182 
1183 	retval = usb_register_dev(intf, &usblp_class);
1184 	if (retval) {
1185 		dev_err(&intf->dev,
1186 			"usblp: Not able to get a minor (base %u, slice default): %d\n",
1187 			USBLP_MINOR_BASE, retval);
1188 		goto abort_intfdata;
1189 	}
1190 	usblp->minor = intf->minor;
1191 	dev_info(&intf->dev,
1192 		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1193 		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1194 		usblp->ifnum,
1195 		usblp->protocol[usblp->current_protocol].alt_setting,
1196 		usblp->current_protocol,
1197 		le16_to_cpu(usblp->dev->descriptor.idVendor),
1198 		le16_to_cpu(usblp->dev->descriptor.idProduct));
1199 
1200 	return 0;
1201 
1202 abort_intfdata:
1203 	usb_set_intfdata(intf, NULL);
1204 abort:
1205 	kfree(usblp->readbuf);
1206 	kfree(usblp->statusbuf);
1207 	kfree(usblp->device_id_string);
1208 	usb_put_intf(usblp->intf);
1209 	kfree(usblp);
1210 abort_ret:
1211 	return retval;
1212 }
1213 
1214 /*
1215  * We are a "new" style driver with usb_device_id table,
1216  * but our requirements are too intricate for simple match to handle.
1217  *
1218  * The "proto_bias" option may be used to specify the preferred protocol
1219  * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1220  * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1221  * then we bind to it.
1222  *
1223  * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1224  * is compatible with a stream of characters. If we find it, we bind to it.
1225  *
1226  * Note that the people from hpoj.sourceforge.net need to be able to
1227  * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1228  * for this purpose.
1229  *
1230  * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1231  * even though it's probably not stream-compatible, because this matches
1232  * the behaviour of the old code.
1233  *
1234  * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1235  * - the unidirectional interface.
1236  */
1237 static int usblp_select_alts(struct usblp *usblp)
1238 {
1239 	struct usb_interface *if_alt;
1240 	struct usb_host_interface *ifd;
1241 	struct usb_endpoint_descriptor *epwrite, *epread;
1242 	int p, i;
1243 	int res;
1244 
1245 	if_alt = usblp->intf;
1246 
1247 	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
1248 		usblp->protocol[p].alt_setting = -1;
1249 
1250 	/* Find out what we have. */
1251 	for (i = 0; i < if_alt->num_altsetting; i++) {
1252 		ifd = &if_alt->altsetting[i];
1253 
1254 		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
1255 		    ifd->desc.bInterfaceSubClass != 1)
1256 			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
1257 				continue;
1258 
1259 		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
1260 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
1261 			continue;
1262 
1263 		/* Look for the expected bulk endpoints. */
1264 		if (ifd->desc.bInterfaceProtocol > 1) {
1265 			res = usb_find_common_endpoints(ifd,
1266 					&epread, &epwrite, NULL, NULL);
1267 		} else {
1268 			epread = NULL;
1269 			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
1270 		}
1271 
1272 		/* Ignore buggy hardware without the right endpoints. */
1273 		if (res)
1274 			continue;
1275 
1276 		/* Turn off reads for buggy bidirectional printers. */
1277 		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1278 			printk(KERN_INFO "usblp%d: Disabling reads from "
1279 			    "problematic bidirectional printer\n",
1280 			    usblp->minor);
1281 			epread = NULL;
1282 		}
1283 
1284 		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1285 				ifd->desc.bAlternateSetting;
1286 		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1287 		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1288 	}
1289 
1290 	/* If our requested protocol is supported, then use it. */
1291 	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1292 	    proto_bias <= USBLP_LAST_PROTOCOL &&
1293 	    usblp->protocol[proto_bias].alt_setting != -1)
1294 		return proto_bias;
1295 
1296 	/* Ordering is important here. */
1297 	if (usblp->protocol[2].alt_setting != -1)
1298 		return 2;
1299 	if (usblp->protocol[1].alt_setting != -1)
1300 		return 1;
1301 	if (usblp->protocol[3].alt_setting != -1)
1302 		return 3;
1303 
1304 	/* If nothing is available, then don't bind to this device. */
1305 	return -1;
1306 }
1307 
1308 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1309 {
1310 	int r, alts;
1311 
1312 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1313 		return -EINVAL;
1314 
1315 	alts = usblp->protocol[protocol].alt_setting;
1316 	if (alts < 0)
1317 		return -EINVAL;
1318 	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1319 	if (r < 0) {
1320 		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1321 			alts, usblp->ifnum);
1322 		return r;
1323 	}
1324 
1325 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1326 	usblp->current_protocol = protocol;
1327 	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1328 		usblp->minor, protocol);
1329 	return 0;
1330 }
1331 
1332 /* Retrieves and caches device ID string.
1333  * Returns length, including length bytes but not null terminator.
1334  * On error, returns a negative errno value. */
1335 static int usblp_cache_device_id_string(struct usblp *usblp)
1336 {
1337 	int err, length;
1338 
1339 	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1340 	if (err < 0) {
1341 		dev_dbg(&usblp->intf->dev,
1342 			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1343 			usblp->minor, err);
1344 		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1345 		return -EIO;
1346 	}
1347 
1348 	/* First two bytes are length in big-endian.
1349 	 * They count themselves, and we copy them into
1350 	 * the user's buffer. */
1351 	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1352 	if (length < 2)
1353 		length = 2;
1354 	else if (length >= USBLP_DEVICE_ID_SIZE)
1355 		length = USBLP_DEVICE_ID_SIZE - 1;
1356 	usblp->device_id_string[length] = '\0';
1357 
1358 	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1359 		usblp->minor, length, &usblp->device_id_string[2]);
1360 
1361 	return length;
1362 }
1363 
1364 static void usblp_disconnect(struct usb_interface *intf)
1365 {
1366 	struct usblp *usblp = usb_get_intfdata(intf);
1367 
1368 	usb_deregister_dev(intf, &usblp_class);
1369 
1370 	if (!usblp || !usblp->dev) {
1371 		dev_err(&intf->dev, "bogus disconnect\n");
1372 		BUG();
1373 	}
1374 
1375 	mutex_lock(&usblp_mutex);
1376 	mutex_lock(&usblp->mut);
1377 	usblp->present = 0;
1378 	wake_up(&usblp->wwait);
1379 	wake_up(&usblp->rwait);
1380 	usb_set_intfdata(intf, NULL);
1381 
1382 	usblp_unlink_urbs(usblp);
1383 	mutex_unlock(&usblp->mut);
1384 	usb_poison_anchored_urbs(&usblp->urbs);
1385 
1386 	if (!usblp->used)
1387 		usblp_cleanup(usblp);
1388 
1389 	mutex_unlock(&usblp_mutex);
1390 }
1391 
1392 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1393 {
1394 	struct usblp *usblp = usb_get_intfdata(intf);
1395 
1396 	usblp_unlink_urbs(usblp);
1397 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1398 	/* not strictly necessary, but just in case */
1399 	wake_up(&usblp->wwait);
1400 	wake_up(&usblp->rwait);
1401 #endif
1402 
1403 	return 0;
1404 }
1405 
1406 static int usblp_resume(struct usb_interface *intf)
1407 {
1408 	struct usblp *usblp = usb_get_intfdata(intf);
1409 	int r;
1410 
1411 	r = handle_bidir(usblp);
1412 
1413 	return r;
1414 }
1415 
1416 static const struct usb_device_id usblp_ids[] = {
1417 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1418 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1419 	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1420 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1421 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1422 	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1423 	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
1424 	{ }						/* Terminating entry */
1425 };
1426 
1427 MODULE_DEVICE_TABLE(usb, usblp_ids);
1428 
1429 static struct usb_driver usblp_driver = {
1430 	.name =		"usblp",
1431 	.probe =	usblp_probe,
1432 	.disconnect =	usblp_disconnect,
1433 	.suspend =	usblp_suspend,
1434 	.resume =	usblp_resume,
1435 	.id_table =	usblp_ids,
1436 	.dev_groups =	usblp_groups,
1437 	.supports_autosuspend =	1,
1438 };
1439 
1440 module_usb_driver(usblp_driver);
1441 
1442 MODULE_AUTHOR(DRIVER_AUTHOR);
1443 MODULE_DESCRIPTION(DRIVER_DESC);
1444 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1445 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1446 MODULE_LICENSE("GPL");
1447