These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / usb / class / usblp.c
1 /*
2  * usblp.c
3  *
4  * Copyright (c) 1999 Michael Gee       <michael@linuxspecific.com>
5  * Copyright (c) 1999 Pavel Machek      <pavel@ucw.cz>
6  * Copyright (c) 2000 Randy Dunlap      <rdunlap@xenotime.net>
7  * Copyright (c) 2000 Vojtech Pavlik    <vojtech@suse.cz>
8  # Copyright (c) 2001 Pete Zaitcev      <zaitcev@redhat.com>
9  # Copyright (c) 2001 David Paschal     <paschal@rcsis.com>
10  * Copyright (c) 2006 Oliver Neukum     <oliver@neukum.name>
11  *
12  * USB Printer Device Class driver for USB printers and printer cables
13  *
14  * Sponsored by SuSE
15  *
16  * ChangeLog:
17  *      v0.1 - thorough cleaning, URBification, almost a rewrite
18  *      v0.2 - some more cleanups
19  *      v0.3 - cleaner again, waitqueue fixes
20  *      v0.4 - fixes in unidirectional mode
21  *      v0.5 - add DEVICE_ID string support
22  *      v0.6 - never time out
23  *      v0.7 - fixed bulk-IN read and poll (David Paschal)
24  *      v0.8 - add devfs support
25  *      v0.9 - fix unplug-while-open paths
26  *      v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
27  *      v0.11 - add proto_bias option (Pete Zaitcev)
28  *      v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
29  *      v0.13 - alloc space for statusbuf (<status> not on stack);
30  *              use usb_alloc_coherent() for read buf & write buf;
31  *      none  - Maintained in Linux kernel after v0.13
32  */
33
34 /*
35  * This program is free software; you can redistribute it and/or modify
36  * it under the terms of the GNU General Public License as published by
37  * the Free Software Foundation; either version 2 of the License, or
38  * (at your option) any later version.
39  *
40  * This program is distributed in the hope that it will be useful,
41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
43  * GNU General Public License for more details.
44  *
45  * You should have received a copy of the GNU General Public License
46  * along with this program; if not, write to the Free Software
47  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
48  */
49
50 #include <linux/module.h>
51 #include <linux/kernel.h>
52 #include <linux/sched.h>
53 #include <linux/signal.h>
54 #include <linux/poll.h>
55 #include <linux/slab.h>
56 #include <linux/lp.h>
57 #include <linux/mutex.h>
58 #undef DEBUG
59 #include <linux/usb.h>
60 #include <linux/usb/ch9.h>
61 #include <linux/ratelimit.h>
62
63 /*
64  * Version Information
65  */
66 #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
67 #define DRIVER_DESC "USB Printer Device Class driver"
68
69 #define USBLP_BUF_SIZE          8192
70 #define USBLP_BUF_SIZE_IN       1024
71 #define USBLP_DEVICE_ID_SIZE    1024
72
73 /* ioctls: */
74 #define IOCNR_GET_DEVICE_ID             1
75 #define IOCNR_GET_PROTOCOLS             2
76 #define IOCNR_SET_PROTOCOL              3
77 #define IOCNR_HP_SET_CHANNEL            4
78 #define IOCNR_GET_BUS_ADDRESS           5
79 #define IOCNR_GET_VID_PID               6
80 #define IOCNR_SOFT_RESET                7
81 /* Get device_id string: */
82 #define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
83 /* The following ioctls were added for http://hpoj.sourceforge.net:
84  * Get two-int array:
85  * [0]=current protocol
86  *     (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
87  *         3=USB_CLASS_PRINTER/1/3),
88  * [1]=supported protocol mask (mask&(1<<n)!=0 means
89  *     USB_CLASS_PRINTER/1/n supported):
90  */
91 #define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
92 /*
93  * Set protocol
94  *     (arg: 1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
95  *         3=USB_CLASS_PRINTER/1/3):
96  */
97 #define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
98 /* Set channel number (HP Vendor-specific command): */
99 #define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
100 /* Get two-int array: [0]=bus number, [1]=device address: */
101 #define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
102 /* Get two-int array: [0]=vendor ID, [1]=product ID: */
103 #define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
104 /* Perform class specific soft reset */
105 #define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
106
107 /*
108  * A DEVICE_ID string may include the printer's serial number.
109  * It should end with a semi-colon (';').
110  * An example from an HP 970C DeskJet printer is (this is one long string,
111  * with the serial number changed):
112 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:                    ;
113  */
114
115 /*
116  * USB Printer Requests
117  */
118
119 #define USBLP_REQ_GET_ID                        0x00
120 #define USBLP_REQ_GET_STATUS                    0x01
121 #define USBLP_REQ_RESET                         0x02
122 #define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST     0x00    /* HP Vendor-specific */
123
124 #define USBLP_MINORS            16
125 #define USBLP_MINOR_BASE        0
126
127 #define USBLP_CTL_TIMEOUT       5000                    /* 5 seconds */
128
129 #define USBLP_FIRST_PROTOCOL    1
130 #define USBLP_LAST_PROTOCOL     3
131 #define USBLP_MAX_PROTOCOLS     (USBLP_LAST_PROTOCOL+1)
132
133 /*
134  * some arbitrary status buffer size;
135  * need a status buffer that is allocated via kmalloc(), not on stack
136  */
137 #define STATUS_BUF_SIZE         8
138
139 /*
140  * Locks down the locking order:
141  * ->wmut locks wstatus.
142  * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
143  * [rw]status. We only touch status when we know the side idle.
144  * ->lock locks what interrupt accesses.
145  */
146 struct usblp {
147         struct usb_device       *dev;                   /* USB device */
148         struct mutex            wmut;
149         struct mutex            mut;
150         spinlock_t              lock;           /* locks rcomplete, wcomplete */
151         char                    *readbuf;               /* read transfer_buffer */
152         char                    *statusbuf;             /* status transfer_buffer */
153         struct usb_anchor       urbs;
154         wait_queue_head_t       rwait, wwait;
155         int                     readcount;              /* Counter for reads */
156         int                     ifnum;                  /* Interface number */
157         struct usb_interface    *intf;                  /* The interface */
158         /*
159          * Alternate-setting numbers and endpoints for each protocol
160          * (USB_CLASS_PRINTER/1/{index=1,2,3}) that the device supports:
161          */
162         struct {
163                 int                             alt_setting;
164                 struct usb_endpoint_descriptor  *epwrite;
165                 struct usb_endpoint_descriptor  *epread;
166         }                       protocol[USBLP_MAX_PROTOCOLS];
167         int                     current_protocol;
168         int                     minor;                  /* minor number of device */
169         int                     wcomplete, rcomplete;
170         int                     wstatus;        /* bytes written or error */
171         int                     rstatus;        /* bytes ready or error */
172         unsigned int            quirks;                 /* quirks flags */
173         unsigned int            flags;                  /* mode flags */
174         unsigned char           used;                   /* True if open */
175         unsigned char           present;                /* True if not disconnected */
176         unsigned char           bidir;                  /* interface is bidirectional */
177         unsigned char           no_paper;               /* Paper Out happened */
178         unsigned char           *device_id_string;      /* IEEE 1284 DEVICE ID string (ptr) */
179                                                         /* first 2 bytes are (big-endian) length */
180 };
181
182 #ifdef DEBUG
183 static void usblp_dump(struct usblp *usblp)
184 {
185         struct device *dev = &usblp->intf->dev;
186         int p;
187
188         dev_dbg(dev, "usblp=0x%p\n", usblp);
189         dev_dbg(dev, "dev=0x%p\n", usblp->dev);
190         dev_dbg(dev, "present=%d\n", usblp->present);
191         dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
192         dev_dbg(dev, "readcount=%d\n", usblp->readcount);
193         dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
194         for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
195                 dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
196                         usblp->protocol[p].alt_setting);
197                 dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
198                         usblp->protocol[p].epwrite);
199                 dev_dbg(dev, "protocol[%d].epread=%p\n", p,
200                         usblp->protocol[p].epread);
201         }
202         dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
203         dev_dbg(dev, "minor=%d\n", usblp->minor);
204         dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
205         dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
206         dev_dbg(dev, "quirks=%d\n", usblp->quirks);
207         dev_dbg(dev, "used=%d\n", usblp->used);
208         dev_dbg(dev, "bidir=%d\n", usblp->bidir);
209         dev_dbg(dev, "device_id_string=\"%s\"\n",
210                 usblp->device_id_string ?
211                         usblp->device_id_string + 2 :
212                         (unsigned char *)"(null)");
213 }
214 #endif
215
216 /* Quirks: various printer quirks are handled by this table & its flags. */
217
218 struct quirk_printer_struct {
219         __u16 vendorId;
220         __u16 productId;
221         unsigned int quirks;
222 };
223
224 #define USBLP_QUIRK_BIDIR       0x1     /* reports bidir but requires unidirectional mode (no INs/reads) */
225 #define USBLP_QUIRK_USB_INIT    0x2     /* needs vendor USB init string */
226 #define USBLP_QUIRK_BAD_CLASS   0x4     /* descriptor uses vendor-specific Class or SubClass */
227
228 static const struct quirk_printer_struct quirk_printers[] = {
229         { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
230         { 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
231         { 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
232         { 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
233         { 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
234         { 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
235         { 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
236         { 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
237         { 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
238         { 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
239         { 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
240         { 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
241         { 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
242         { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
243         { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
244         { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
245         { 0, 0 }
246 };
247
248 static int usblp_wwait(struct usblp *usblp, int nonblock);
249 static int usblp_wtest(struct usblp *usblp, int nonblock);
250 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
251 static int usblp_rtest(struct usblp *usblp, int nonblock);
252 static int usblp_submit_read(struct usblp *usblp);
253 static int usblp_select_alts(struct usblp *usblp);
254 static int usblp_set_protocol(struct usblp *usblp, int protocol);
255 static int usblp_cache_device_id_string(struct usblp *usblp);
256
257 /* forward reference to make our lives easier */
258 static struct usb_driver usblp_driver;
259 static DEFINE_MUTEX(usblp_mutex);       /* locks the existence of usblp's */
260
261 /*
262  * Functions for usblp control messages.
263  */
264
265 static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
266 {
267         int retval;
268         int index = usblp->ifnum;
269
270         /* High byte has the interface index.
271            Low byte has the alternate setting.
272          */
273         if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
274                 index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
275
276         retval = usb_control_msg(usblp->dev,
277                 dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
278                 request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
279         dev_dbg(&usblp->intf->dev,
280                 "usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
281                 request, !!dir, recip, value, index, len, retval);
282         return retval < 0 ? retval : 0;
283 }
284
285 #define usblp_read_status(usblp, status)\
286         usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
287 #define usblp_get_id(usblp, config, id, maxlen)\
288         usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
289 #define usblp_reset(usblp)\
290         usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
291
292 #define usblp_hp_channel_change_request(usblp, channel, buffer) \
293         usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
294
295 /*
296  * See the description for usblp_select_alts() below for the usage
297  * explanation.  Look into your /proc/bus/usb/devices and dmesg in
298  * case of any trouble.
299  */
300 static int proto_bias = -1;
301
302 /*
303  * URB callback.
304  */
305
306 static void usblp_bulk_read(struct urb *urb)
307 {
308         struct usblp *usblp = urb->context;
309         int status = urb->status;
310
311         if (usblp->present && usblp->used) {
312                 if (status)
313                         printk(KERN_WARNING "usblp%d: "
314                             "nonzero read bulk status received: %d\n",
315                             usblp->minor, status);
316         }
317         spin_lock(&usblp->lock);
318         if (status < 0)
319                 usblp->rstatus = status;
320         else
321                 usblp->rstatus = urb->actual_length;
322         usblp->rcomplete = 1;
323         wake_up(&usblp->rwait);
324         spin_unlock(&usblp->lock);
325
326         usb_free_urb(urb);
327 }
328
329 static void usblp_bulk_write(struct urb *urb)
330 {
331         struct usblp *usblp = urb->context;
332         int status = urb->status;
333
334         if (usblp->present && usblp->used) {
335                 if (status)
336                         printk(KERN_WARNING "usblp%d: "
337                             "nonzero write bulk status received: %d\n",
338                             usblp->minor, status);
339         }
340         spin_lock(&usblp->lock);
341         if (status < 0)
342                 usblp->wstatus = status;
343         else
344                 usblp->wstatus = urb->actual_length;
345         usblp->no_paper = 0;
346         usblp->wcomplete = 1;
347         wake_up(&usblp->wwait);
348         spin_unlock(&usblp->lock);
349
350         usb_free_urb(urb);
351 }
352
353 /*
354  * Get and print printer errors.
355  */
356
357 static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
358
359 static int usblp_check_status(struct usblp *usblp, int err)
360 {
361         unsigned char status, newerr = 0;
362         int error;
363
364         mutex_lock(&usblp->mut);
365         if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
366                 mutex_unlock(&usblp->mut);
367                 printk_ratelimited(KERN_ERR
368                                 "usblp%d: error %d reading printer status\n",
369                                 usblp->minor, error);
370                 return 0;
371         }
372         status = *usblp->statusbuf;
373         mutex_unlock(&usblp->mut);
374
375         if (~status & LP_PERRORP)
376                 newerr = 3;
377         if (status & LP_POUTPA)
378                 newerr = 1;
379         if (~status & LP_PSELECD)
380                 newerr = 2;
381
382         if (newerr != err) {
383                 printk(KERN_INFO "usblp%d: %s\n",
384                    usblp->minor, usblp_messages[newerr]);
385         }
386
387         return newerr;
388 }
389
390 static int handle_bidir(struct usblp *usblp)
391 {
392         if (usblp->bidir && usblp->used) {
393                 if (usblp_submit_read(usblp) < 0)
394                         return -EIO;
395         }
396         return 0;
397 }
398
399 /*
400  * File op functions.
401  */
402
403 static int usblp_open(struct inode *inode, struct file *file)
404 {
405         int minor = iminor(inode);
406         struct usblp *usblp;
407         struct usb_interface *intf;
408         int retval;
409
410         if (minor < 0)
411                 return -ENODEV;
412
413         mutex_lock(&usblp_mutex);
414
415         retval = -ENODEV;
416         intf = usb_find_interface(&usblp_driver, minor);
417         if (!intf)
418                 goto out;
419         usblp = usb_get_intfdata(intf);
420         if (!usblp || !usblp->dev || !usblp->present)
421                 goto out;
422
423         retval = -EBUSY;
424         if (usblp->used)
425                 goto out;
426
427         /*
428          * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
429          *  - We do not want persistent state which close(2) does not clear
430          *  - It is not used anyway, according to CUPS people
431          */
432
433         retval = usb_autopm_get_interface(intf);
434         if (retval < 0)
435                 goto out;
436         usblp->used = 1;
437         file->private_data = usblp;
438
439         usblp->wcomplete = 1; /* we begin writeable */
440         usblp->wstatus = 0;
441         usblp->rcomplete = 0;
442
443         if (handle_bidir(usblp) < 0) {
444                 usb_autopm_put_interface(intf);
445                 usblp->used = 0;
446                 file->private_data = NULL;
447                 retval = -EIO;
448         }
449 out:
450         mutex_unlock(&usblp_mutex);
451         return retval;
452 }
453
454 static void usblp_cleanup(struct usblp *usblp)
455 {
456         printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
457
458         kfree(usblp->readbuf);
459         kfree(usblp->device_id_string);
460         kfree(usblp->statusbuf);
461         kfree(usblp);
462 }
463
464 static void usblp_unlink_urbs(struct usblp *usblp)
465 {
466         usb_kill_anchored_urbs(&usblp->urbs);
467 }
468
469 static int usblp_release(struct inode *inode, struct file *file)
470 {
471         struct usblp *usblp = file->private_data;
472
473         usblp->flags &= ~LP_ABORT;
474
475         mutex_lock(&usblp_mutex);
476         usblp->used = 0;
477         if (usblp->present) {
478                 usblp_unlink_urbs(usblp);
479                 usb_autopm_put_interface(usblp->intf);
480         } else          /* finish cleanup from disconnect */
481                 usblp_cleanup(usblp);
482         mutex_unlock(&usblp_mutex);
483         return 0;
484 }
485
486 /* No kernel lock - fine */
487 static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
488 {
489         int ret;
490         unsigned long flags;
491
492         struct usblp *usblp = file->private_data;
493         /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
494         poll_wait(file, &usblp->rwait, wait);
495         poll_wait(file, &usblp->wwait, wait);
496         spin_lock_irqsave(&usblp->lock, flags);
497         ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
498            ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
499         spin_unlock_irqrestore(&usblp->lock, flags);
500         return ret;
501 }
502
503 static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
504 {
505         struct usblp *usblp = file->private_data;
506         int length, err, i;
507         unsigned char newChannel;
508         int status;
509         int twoints[2];
510         int retval = 0;
511
512         mutex_lock(&usblp->mut);
513         if (!usblp->present) {
514                 retval = -ENODEV;
515                 goto done;
516         }
517
518         dev_dbg(&usblp->intf->dev,
519                 "usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
520                 _IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
521
522         if (_IOC_TYPE(cmd) == 'P')      /* new-style ioctl number */
523
524                 switch (_IOC_NR(cmd)) {
525
526                 case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
527                         if (_IOC_DIR(cmd) != _IOC_READ) {
528                                 retval = -EINVAL;
529                                 goto done;
530                         }
531
532                         length = usblp_cache_device_id_string(usblp);
533                         if (length < 0) {
534                                 retval = length;
535                                 goto done;
536                         }
537                         if (length > _IOC_SIZE(cmd))
538                                 length = _IOC_SIZE(cmd); /* truncate */
539
540                         if (copy_to_user((void __user *) arg,
541                                         usblp->device_id_string,
542                                         (unsigned long) length)) {
543                                 retval = -EFAULT;
544                                 goto done;
545                         }
546
547                         break;
548
549                 case IOCNR_GET_PROTOCOLS:
550                         if (_IOC_DIR(cmd) != _IOC_READ ||
551                             _IOC_SIZE(cmd) < sizeof(twoints)) {
552                                 retval = -EINVAL;
553                                 goto done;
554                         }
555
556                         twoints[0] = usblp->current_protocol;
557                         twoints[1] = 0;
558                         for (i = USBLP_FIRST_PROTOCOL;
559                              i <= USBLP_LAST_PROTOCOL; i++) {
560                                 if (usblp->protocol[i].alt_setting >= 0)
561                                         twoints[1] |= (1<<i);
562                         }
563
564                         if (copy_to_user((void __user *)arg,
565                                         (unsigned char *)twoints,
566                                         sizeof(twoints))) {
567                                 retval = -EFAULT;
568                                 goto done;
569                         }
570
571                         break;
572
573                 case IOCNR_SET_PROTOCOL:
574                         if (_IOC_DIR(cmd) != _IOC_WRITE) {
575                                 retval = -EINVAL;
576                                 goto done;
577                         }
578
579 #ifdef DEBUG
580                         if (arg == -10) {
581                                 usblp_dump(usblp);
582                                 break;
583                         }
584 #endif
585
586                         usblp_unlink_urbs(usblp);
587                         retval = usblp_set_protocol(usblp, arg);
588                         if (retval < 0) {
589                                 usblp_set_protocol(usblp,
590                                         usblp->current_protocol);
591                         }
592                         break;
593
594                 case IOCNR_HP_SET_CHANNEL:
595                         if (_IOC_DIR(cmd) != _IOC_WRITE ||
596                             le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
597                             usblp->quirks & USBLP_QUIRK_BIDIR) {
598                                 retval = -EINVAL;
599                                 goto done;
600                         }
601
602                         err = usblp_hp_channel_change_request(usblp,
603                                 arg, &newChannel);
604                         if (err < 0) {
605                                 dev_err(&usblp->dev->dev,
606                                         "usblp%d: error = %d setting "
607                                         "HP channel\n",
608                                         usblp->minor, err);
609                                 retval = -EIO;
610                                 goto done;
611                         }
612
613                         dev_dbg(&usblp->intf->dev,
614                                 "usblp%d requested/got HP channel %ld/%d\n",
615                                 usblp->minor, arg, newChannel);
616                         break;
617
618                 case IOCNR_GET_BUS_ADDRESS:
619                         if (_IOC_DIR(cmd) != _IOC_READ ||
620                             _IOC_SIZE(cmd) < sizeof(twoints)) {
621                                 retval = -EINVAL;
622                                 goto done;
623                         }
624
625                         twoints[0] = usblp->dev->bus->busnum;
626                         twoints[1] = usblp->dev->devnum;
627                         if (copy_to_user((void __user *)arg,
628                                         (unsigned char *)twoints,
629                                         sizeof(twoints))) {
630                                 retval = -EFAULT;
631                                 goto done;
632                         }
633
634                         dev_dbg(&usblp->intf->dev,
635                                 "usblp%d is bus=%d, device=%d\n",
636                                 usblp->minor, twoints[0], twoints[1]);
637                         break;
638
639                 case IOCNR_GET_VID_PID:
640                         if (_IOC_DIR(cmd) != _IOC_READ ||
641                             _IOC_SIZE(cmd) < sizeof(twoints)) {
642                                 retval = -EINVAL;
643                                 goto done;
644                         }
645
646                         twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
647                         twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
648                         if (copy_to_user((void __user *)arg,
649                                         (unsigned char *)twoints,
650                                         sizeof(twoints))) {
651                                 retval = -EFAULT;
652                                 goto done;
653                         }
654
655                         dev_dbg(&usblp->intf->dev,
656                                 "usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
657                                 usblp->minor, twoints[0], twoints[1]);
658                         break;
659
660                 case IOCNR_SOFT_RESET:
661                         if (_IOC_DIR(cmd) != _IOC_NONE) {
662                                 retval = -EINVAL;
663                                 goto done;
664                         }
665                         retval = usblp_reset(usblp);
666                         break;
667                 default:
668                         retval = -ENOTTY;
669                 }
670         else    /* old-style ioctl value */
671                 switch (cmd) {
672
673                 case LPGETSTATUS:
674                         retval = usblp_read_status(usblp, usblp->statusbuf);
675                         if (retval) {
676                                 printk_ratelimited(KERN_ERR "usblp%d:"
677                                             "failed reading printer status (%d)\n",
678                                             usblp->minor, retval);
679                                 retval = -EIO;
680                                 goto done;
681                         }
682                         status = *usblp->statusbuf;
683                         if (copy_to_user((void __user *)arg, &status, sizeof(int)))
684                                 retval = -EFAULT;
685                         break;
686
687                 case LPABORT:
688                         if (arg)
689                                 usblp->flags |= LP_ABORT;
690                         else
691                                 usblp->flags &= ~LP_ABORT;
692                         break;
693
694                 default:
695                         retval = -ENOTTY;
696                 }
697
698 done:
699         mutex_unlock(&usblp->mut);
700         return retval;
701 }
702
703 static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
704 {
705         struct urb *urb;
706         char *writebuf;
707
708         writebuf = kmalloc(transfer_length, GFP_KERNEL);
709         if (writebuf == NULL)
710                 return NULL;
711         urb = usb_alloc_urb(0, GFP_KERNEL);
712         if (urb == NULL) {
713                 kfree(writebuf);
714                 return NULL;
715         }
716
717         usb_fill_bulk_urb(urb, usblp->dev,
718                 usb_sndbulkpipe(usblp->dev,
719                  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
720                 writebuf, transfer_length, usblp_bulk_write, usblp);
721         urb->transfer_flags |= URB_FREE_BUFFER;
722
723         return urb;
724 }
725
726 static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
727 {
728         struct usblp *usblp = file->private_data;
729         struct urb *writeurb;
730         int rv;
731         int transfer_length;
732         ssize_t writecount = 0;
733
734         if (mutex_lock_interruptible(&usblp->wmut)) {
735                 rv = -EINTR;
736                 goto raise_biglock;
737         }
738         if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
739                 goto raise_wait;
740
741         while (writecount < count) {
742                 /*
743                  * Step 1: Submit next block.
744                  */
745                 if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
746                         transfer_length = USBLP_BUF_SIZE;
747
748                 rv = -ENOMEM;
749                 writeurb = usblp_new_writeurb(usblp, transfer_length);
750                 if (writeurb == NULL)
751                         goto raise_urb;
752                 usb_anchor_urb(writeurb, &usblp->urbs);
753
754                 if (copy_from_user(writeurb->transfer_buffer,
755                                    buffer + writecount, transfer_length)) {
756                         rv = -EFAULT;
757                         goto raise_badaddr;
758                 }
759
760                 spin_lock_irq(&usblp->lock);
761                 usblp->wcomplete = 0;
762                 spin_unlock_irq(&usblp->lock);
763                 if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
764                         usblp->wstatus = 0;
765                         spin_lock_irq(&usblp->lock);
766                         usblp->no_paper = 0;
767                         usblp->wcomplete = 1;
768                         wake_up(&usblp->wwait);
769                         spin_unlock_irq(&usblp->lock);
770                         if (rv != -ENOMEM)
771                                 rv = -EIO;
772                         goto raise_submit;
773                 }
774
775                 /*
776                  * Step 2: Wait for transfer to end, collect results.
777                  */
778                 rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
779                 if (rv < 0) {
780                         if (rv == -EAGAIN) {
781                                 /* Presume that it's going to complete well. */
782                                 writecount += transfer_length;
783                         }
784                         if (rv == -ENOSPC) {
785                                 spin_lock_irq(&usblp->lock);
786                                 usblp->no_paper = 1;    /* Mark for poll(2) */
787                                 spin_unlock_irq(&usblp->lock);
788                                 writecount += transfer_length;
789                         }
790                         /* Leave URB dangling, to be cleaned on close. */
791                         goto collect_error;
792                 }
793
794                 if (usblp->wstatus < 0) {
795                         rv = -EIO;
796                         goto collect_error;
797                 }
798                 /*
799                  * This is critical: it must be our URB, not other writer's.
800                  * The wmut exists mainly to cover us here.
801                  */
802                 writecount += usblp->wstatus;
803         }
804
805         mutex_unlock(&usblp->wmut);
806         return writecount;
807
808 raise_submit:
809 raise_badaddr:
810         usb_unanchor_urb(writeurb);
811         usb_free_urb(writeurb);
812 raise_urb:
813 raise_wait:
814 collect_error:          /* Out of raise sequence */
815         mutex_unlock(&usblp->wmut);
816 raise_biglock:
817         return writecount ? writecount : rv;
818 }
819
820 /*
821  * Notice that we fail to restart in a few cases: on EFAULT, on restart
822  * error, etc. This is the historical behaviour. In all such cases we return
823  * EIO, and applications loop in order to get the new read going.
824  */
825 static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
826 {
827         struct usblp *usblp = file->private_data;
828         ssize_t count;
829         ssize_t avail;
830         int rv;
831
832         if (!usblp->bidir)
833                 return -EINVAL;
834
835         rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
836         if (rv < 0)
837                 return rv;
838
839         if ((avail = usblp->rstatus) < 0) {
840                 printk(KERN_ERR "usblp%d: error %d reading from printer\n",
841                     usblp->minor, (int)avail);
842                 usblp_submit_read(usblp);
843                 count = -EIO;
844                 goto done;
845         }
846
847         count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
848         if (count != 0 &&
849             copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
850                 count = -EFAULT;
851                 goto done;
852         }
853
854         if ((usblp->readcount += count) == avail) {
855                 if (usblp_submit_read(usblp) < 0) {
856                         /* We don't want to leak USB return codes into errno. */
857                         if (count == 0)
858                                 count = -EIO;
859                         goto done;
860                 }
861         }
862
863 done:
864         mutex_unlock(&usblp->mut);
865         return count;
866 }
867
868 /*
869  * Wait for the write path to come idle.
870  * This is called under the ->wmut, so the idle path stays idle.
871  *
872  * Our write path has a peculiar property: it does not buffer like a tty,
873  * but waits for the write to succeed. This allows our ->release to bug out
874  * without waiting for writes to drain. But it obviously does not work
875  * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
876  * select(2) or poll(2) to wait for the buffer to drain before closing.
877  * Alternatively, set blocking mode with fcntl and issue a zero-size write.
878  */
879 static int usblp_wwait(struct usblp *usblp, int nonblock)
880 {
881         DECLARE_WAITQUEUE(waita, current);
882         int rc;
883         int err = 0;
884
885         add_wait_queue(&usblp->wwait, &waita);
886         for (;;) {
887                 if (mutex_lock_interruptible(&usblp->mut)) {
888                         rc = -EINTR;
889                         break;
890                 }
891                 set_current_state(TASK_INTERRUPTIBLE);
892                 rc = usblp_wtest(usblp, nonblock);
893                 mutex_unlock(&usblp->mut);
894                 if (rc <= 0)
895                         break;
896
897                 if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
898                         if (usblp->flags & LP_ABORT) {
899                                 err = usblp_check_status(usblp, err);
900                                 if (err == 1) { /* Paper out */
901                                         rc = -ENOSPC;
902                                         break;
903                                 }
904                         } else {
905                                 /* Prod the printer, Gentoo#251237. */
906                                 mutex_lock(&usblp->mut);
907                                 usblp_read_status(usblp, usblp->statusbuf);
908                                 mutex_unlock(&usblp->mut);
909                         }
910                 }
911         }
912         set_current_state(TASK_RUNNING);
913         remove_wait_queue(&usblp->wwait, &waita);
914         return rc;
915 }
916
917 static int usblp_wtest(struct usblp *usblp, int nonblock)
918 {
919         unsigned long flags;
920
921         if (!usblp->present)
922                 return -ENODEV;
923         if (signal_pending(current))
924                 return -EINTR;
925         spin_lock_irqsave(&usblp->lock, flags);
926         if (usblp->wcomplete) {
927                 spin_unlock_irqrestore(&usblp->lock, flags);
928                 return 0;
929         }
930         spin_unlock_irqrestore(&usblp->lock, flags);
931         if (nonblock)
932                 return -EAGAIN;
933         return 1;
934 }
935
936 /*
937  * Wait for read bytes to become available. This probably should have been
938  * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
939  * name for functions which lock and return.
940  *
941  * We do not use wait_event_interruptible because it makes locking iffy.
942  */
943 static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
944 {
945         DECLARE_WAITQUEUE(waita, current);
946         int rc;
947
948         add_wait_queue(&usblp->rwait, &waita);
949         for (;;) {
950                 if (mutex_lock_interruptible(&usblp->mut)) {
951                         rc = -EINTR;
952                         break;
953                 }
954                 set_current_state(TASK_INTERRUPTIBLE);
955                 if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
956                         mutex_unlock(&usblp->mut);
957                         break;
958                 }
959                 if (rc == 0)    /* Keep it locked */
960                         break;
961                 mutex_unlock(&usblp->mut);
962                 schedule();
963         }
964         set_current_state(TASK_RUNNING);
965         remove_wait_queue(&usblp->rwait, &waita);
966         return rc;
967 }
968
969 static int usblp_rtest(struct usblp *usblp, int nonblock)
970 {
971         unsigned long flags;
972
973         if (!usblp->present)
974                 return -ENODEV;
975         if (signal_pending(current))
976                 return -EINTR;
977         spin_lock_irqsave(&usblp->lock, flags);
978         if (usblp->rcomplete) {
979                 spin_unlock_irqrestore(&usblp->lock, flags);
980                 return 0;
981         }
982         spin_unlock_irqrestore(&usblp->lock, flags);
983         if (nonblock)
984                 return -EAGAIN;
985         return 1;
986 }
987
988 /*
989  * Please check ->bidir and other such things outside for now.
990  */
991 static int usblp_submit_read(struct usblp *usblp)
992 {
993         struct urb *urb;
994         unsigned long flags;
995         int rc;
996
997         rc = -ENOMEM;
998         urb = usb_alloc_urb(0, GFP_KERNEL);
999         if (urb == NULL)
1000                 goto raise_urb;
1001
1002         usb_fill_bulk_urb(urb, usblp->dev,
1003                 usb_rcvbulkpipe(usblp->dev,
1004                   usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
1005                 usblp->readbuf, USBLP_BUF_SIZE_IN,
1006                 usblp_bulk_read, usblp);
1007         usb_anchor_urb(urb, &usblp->urbs);
1008
1009         spin_lock_irqsave(&usblp->lock, flags);
1010         usblp->readcount = 0; /* XXX Why here? */
1011         usblp->rcomplete = 0;
1012         spin_unlock_irqrestore(&usblp->lock, flags);
1013         if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
1014                 dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
1015                 spin_lock_irqsave(&usblp->lock, flags);
1016                 usblp->rstatus = rc;
1017                 usblp->rcomplete = 1;
1018                 spin_unlock_irqrestore(&usblp->lock, flags);
1019                 goto raise_submit;
1020         }
1021
1022         return 0;
1023
1024 raise_submit:
1025         usb_unanchor_urb(urb);
1026         usb_free_urb(urb);
1027 raise_urb:
1028         return rc;
1029 }
1030
1031 /*
1032  * Checks for printers that have quirks, such as requiring unidirectional
1033  * communication but reporting bidirectional; currently some HP printers
1034  * have this flaw (HP 810, 880, 895, etc.), or needing an init string
1035  * sent at each open (like some Epsons).
1036  * Returns 1 if found, 0 if not found.
1037  *
1038  * HP recommended that we use the bidirectional interface but
1039  * don't attempt any bulk IN transfers from the IN endpoint.
1040  * Here's some more detail on the problem:
1041  * The problem is not that it isn't bidirectional though. The problem
1042  * is that if you request a device ID, or status information, while
1043  * the buffers are full, the return data will end up in the print data
1044  * buffer. For example if you make sure you never request the device ID
1045  * while you are sending print data, and you don't try to query the
1046  * printer status every couple of milliseconds, you will probably be OK.
1047  */
1048 static unsigned int usblp_quirks(__u16 vendor, __u16 product)
1049 {
1050         int i;
1051
1052         for (i = 0; quirk_printers[i].vendorId; i++) {
1053                 if (vendor == quirk_printers[i].vendorId &&
1054                     product == quirk_printers[i].productId)
1055                         return quirk_printers[i].quirks;
1056         }
1057         return 0;
1058 }
1059
1060 static const struct file_operations usblp_fops = {
1061         .owner =        THIS_MODULE,
1062         .read =         usblp_read,
1063         .write =        usblp_write,
1064         .poll =         usblp_poll,
1065         .unlocked_ioctl =       usblp_ioctl,
1066         .compat_ioctl =         usblp_ioctl,
1067         .open =         usblp_open,
1068         .release =      usblp_release,
1069         .llseek =       noop_llseek,
1070 };
1071
1072 static char *usblp_devnode(struct device *dev, umode_t *mode)
1073 {
1074         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
1075 }
1076
1077 static struct usb_class_driver usblp_class = {
1078         .name =         "lp%d",
1079         .devnode =      usblp_devnode,
1080         .fops =         &usblp_fops,
1081         .minor_base =   USBLP_MINOR_BASE,
1082 };
1083
1084 static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
1085 {
1086         struct usb_interface *intf = to_usb_interface(dev);
1087         struct usblp *usblp = usb_get_intfdata(intf);
1088
1089         if (usblp->device_id_string[0] == 0 &&
1090             usblp->device_id_string[1] == 0)
1091                 return 0;
1092
1093         return sprintf(buf, "%s", usblp->device_id_string+2);
1094 }
1095
1096 static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
1097
1098 static int usblp_probe(struct usb_interface *intf,
1099                        const struct usb_device_id *id)
1100 {
1101         struct usb_device *dev = interface_to_usbdev(intf);
1102         struct usblp *usblp;
1103         int protocol;
1104         int retval;
1105
1106         /* Malloc and start initializing usblp structure so we can use it
1107          * directly. */
1108         usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
1109         if (!usblp) {
1110                 retval = -ENOMEM;
1111                 goto abort_ret;
1112         }
1113         usblp->dev = dev;
1114         mutex_init(&usblp->wmut);
1115         mutex_init(&usblp->mut);
1116         spin_lock_init(&usblp->lock);
1117         init_waitqueue_head(&usblp->rwait);
1118         init_waitqueue_head(&usblp->wwait);
1119         init_usb_anchor(&usblp->urbs);
1120         usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
1121         usblp->intf = intf;
1122
1123         /* Malloc device ID string buffer to the largest expected length,
1124          * since we can re-query it on an ioctl and a dynamic string
1125          * could change in length. */
1126         if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
1127                 retval = -ENOMEM;
1128                 goto abort;
1129         }
1130
1131         /*
1132          * Allocate read buffer. We somewhat wastefully
1133          * malloc both regardless of bidirectionality, because the
1134          * alternate setting can be changed later via an ioctl.
1135          */
1136         if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
1137                 retval = -ENOMEM;
1138                 goto abort;
1139         }
1140
1141         /* Allocate buffer for printer status */
1142         usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
1143         if (!usblp->statusbuf) {
1144                 retval = -ENOMEM;
1145                 goto abort;
1146         }
1147
1148         /* Lookup quirks for this printer. */
1149         usblp->quirks = usblp_quirks(
1150                 le16_to_cpu(dev->descriptor.idVendor),
1151                 le16_to_cpu(dev->descriptor.idProduct));
1152
1153         /* Analyze and pick initial alternate settings and endpoints. */
1154         protocol = usblp_select_alts(usblp);
1155         if (protocol < 0) {
1156                 dev_dbg(&intf->dev,
1157                         "incompatible printer-class device 0x%4.4X/0x%4.4X\n",
1158                         le16_to_cpu(dev->descriptor.idVendor),
1159                         le16_to_cpu(dev->descriptor.idProduct));
1160                 retval = -ENODEV;
1161                 goto abort;
1162         }
1163
1164         /* Setup the selected alternate setting and endpoints. */
1165         if (usblp_set_protocol(usblp, protocol) < 0) {
1166                 retval = -ENODEV;       /* ->probe isn't ->ioctl */
1167                 goto abort;
1168         }
1169
1170         /* Retrieve and store the device ID string. */
1171         usblp_cache_device_id_string(usblp);
1172         retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
1173         if (retval)
1174                 goto abort_intfdata;
1175
1176 #ifdef DEBUG
1177         usblp_check_status(usblp, 0);
1178 #endif
1179
1180         usb_set_intfdata(intf, usblp);
1181
1182         usblp->present = 1;
1183
1184         retval = usb_register_dev(intf, &usblp_class);
1185         if (retval) {
1186                 dev_err(&intf->dev,
1187                         "usblp: Not able to get a minor (base %u, slice default): %d\n",
1188                         USBLP_MINOR_BASE, retval);
1189                 goto abort_intfdata;
1190         }
1191         usblp->minor = intf->minor;
1192         dev_info(&intf->dev,
1193                 "usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
1194                 usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
1195                 usblp->ifnum,
1196                 usblp->protocol[usblp->current_protocol].alt_setting,
1197                 usblp->current_protocol,
1198                 le16_to_cpu(usblp->dev->descriptor.idVendor),
1199                 le16_to_cpu(usblp->dev->descriptor.idProduct));
1200
1201         return 0;
1202
1203 abort_intfdata:
1204         usb_set_intfdata(intf, NULL);
1205         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1206 abort:
1207         kfree(usblp->readbuf);
1208         kfree(usblp->statusbuf);
1209         kfree(usblp->device_id_string);
1210         kfree(usblp);
1211 abort_ret:
1212         return retval;
1213 }
1214
1215 /*
1216  * We are a "new" style driver with usb_device_id table,
1217  * but our requirements are too intricate for simple match to handle.
1218  *
1219  * The "proto_bias" option may be used to specify the preferred protocol
1220  * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
1221  * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
1222  * then we bind to it.
1223  *
1224  * The best interface for us is USB_CLASS_PRINTER/1/2, because it
1225  * is compatible with a stream of characters. If we find it, we bind to it.
1226  *
1227  * Note that the people from hpoj.sourceforge.net need to be able to
1228  * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
1229  * for this purpose.
1230  *
1231  * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
1232  * even though it's probably not stream-compatible, because this matches
1233  * the behaviour of the old code.
1234  *
1235  * If nothing else, we bind to USB_CLASS_PRINTER/1/1
1236  * - the unidirectional interface.
1237  */
1238 static int usblp_select_alts(struct usblp *usblp)
1239 {
1240         struct usb_interface *if_alt;
1241         struct usb_host_interface *ifd;
1242         struct usb_endpoint_descriptor *epd, *epwrite, *epread;
1243         int p, i, e;
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 bulk OUT and IN endpoints. */
1264                 epwrite = epread = NULL;
1265                 for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
1266                         epd = &ifd->endpoint[e].desc;
1267
1268                         if (usb_endpoint_is_bulk_out(epd))
1269                                 if (!epwrite)
1270                                         epwrite = epd;
1271
1272                         if (usb_endpoint_is_bulk_in(epd))
1273                                 if (!epread)
1274                                         epread = epd;
1275                 }
1276
1277                 /* Ignore buggy hardware without the right endpoints. */
1278                 if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
1279                         continue;
1280
1281                 /*
1282                  * Turn off reads for USB_CLASS_PRINTER/1/1 (unidirectional)
1283                  * interfaces and buggy bidirectional printers.
1284                  */
1285                 if (ifd->desc.bInterfaceProtocol == 1) {
1286                         epread = NULL;
1287                 } else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
1288                         printk(KERN_INFO "usblp%d: Disabling reads from "
1289                             "problematic bidirectional printer\n",
1290                             usblp->minor);
1291                         epread = NULL;
1292                 }
1293
1294                 usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
1295                                 ifd->desc.bAlternateSetting;
1296                 usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
1297                 usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
1298         }
1299
1300         /* If our requested protocol is supported, then use it. */
1301         if (proto_bias >= USBLP_FIRST_PROTOCOL &&
1302             proto_bias <= USBLP_LAST_PROTOCOL &&
1303             usblp->protocol[proto_bias].alt_setting != -1)
1304                 return proto_bias;
1305
1306         /* Ordering is important here. */
1307         if (usblp->protocol[2].alt_setting != -1)
1308                 return 2;
1309         if (usblp->protocol[1].alt_setting != -1)
1310                 return 1;
1311         if (usblp->protocol[3].alt_setting != -1)
1312                 return 3;
1313
1314         /* If nothing is available, then don't bind to this device. */
1315         return -1;
1316 }
1317
1318 static int usblp_set_protocol(struct usblp *usblp, int protocol)
1319 {
1320         int r, alts;
1321
1322         if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
1323                 return -EINVAL;
1324
1325         alts = usblp->protocol[protocol].alt_setting;
1326         if (alts < 0)
1327                 return -EINVAL;
1328         r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
1329         if (r < 0) {
1330                 printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
1331                         alts, usblp->ifnum);
1332                 return r;
1333         }
1334
1335         usblp->bidir = (usblp->protocol[protocol].epread != NULL);
1336         usblp->current_protocol = protocol;
1337         dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
1338                 usblp->minor, protocol);
1339         return 0;
1340 }
1341
1342 /* Retrieves and caches device ID string.
1343  * Returns length, including length bytes but not null terminator.
1344  * On error, returns a negative errno value. */
1345 static int usblp_cache_device_id_string(struct usblp *usblp)
1346 {
1347         int err, length;
1348
1349         err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
1350         if (err < 0) {
1351                 dev_dbg(&usblp->intf->dev,
1352                         "usblp%d: error = %d reading IEEE-1284 Device ID string\n",
1353                         usblp->minor, err);
1354                 usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
1355                 return -EIO;
1356         }
1357
1358         /* First two bytes are length in big-endian.
1359          * They count themselves, and we copy them into
1360          * the user's buffer. */
1361         length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
1362         if (length < 2)
1363                 length = 2;
1364         else if (length >= USBLP_DEVICE_ID_SIZE)
1365                 length = USBLP_DEVICE_ID_SIZE - 1;
1366         usblp->device_id_string[length] = '\0';
1367
1368         dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
1369                 usblp->minor, length, &usblp->device_id_string[2]);
1370
1371         return length;
1372 }
1373
1374 static void usblp_disconnect(struct usb_interface *intf)
1375 {
1376         struct usblp *usblp = usb_get_intfdata(intf);
1377
1378         usb_deregister_dev(intf, &usblp_class);
1379
1380         if (!usblp || !usblp->dev) {
1381                 dev_err(&intf->dev, "bogus disconnect\n");
1382                 BUG();
1383         }
1384
1385         device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
1386
1387         mutex_lock(&usblp_mutex);
1388         mutex_lock(&usblp->mut);
1389         usblp->present = 0;
1390         wake_up(&usblp->wwait);
1391         wake_up(&usblp->rwait);
1392         usb_set_intfdata(intf, NULL);
1393
1394         usblp_unlink_urbs(usblp);
1395         mutex_unlock(&usblp->mut);
1396
1397         if (!usblp->used)
1398                 usblp_cleanup(usblp);
1399         mutex_unlock(&usblp_mutex);
1400 }
1401
1402 static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
1403 {
1404         struct usblp *usblp = usb_get_intfdata(intf);
1405
1406         usblp_unlink_urbs(usblp);
1407 #if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
1408         /* not strictly necessary, but just in case */
1409         wake_up(&usblp->wwait);
1410         wake_up(&usblp->rwait);
1411 #endif
1412
1413         return 0;
1414 }
1415
1416 static int usblp_resume(struct usb_interface *intf)
1417 {
1418         struct usblp *usblp = usb_get_intfdata(intf);
1419         int r;
1420
1421         r = handle_bidir(usblp);
1422
1423         return r;
1424 }
1425
1426 static const struct usb_device_id usblp_ids[] = {
1427         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
1428         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
1429         { USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
1430         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
1431         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
1432         { USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
1433         { USB_DEVICE(0x04b8, 0x0202) }, /* Seiko Epson Receipt Printer M129C */
1434         { }                                             /* Terminating entry */
1435 };
1436
1437 MODULE_DEVICE_TABLE(usb, usblp_ids);
1438
1439 static struct usb_driver usblp_driver = {
1440         .name =         "usblp",
1441         .probe =        usblp_probe,
1442         .disconnect =   usblp_disconnect,
1443         .suspend =      usblp_suspend,
1444         .resume =       usblp_resume,
1445         .id_table =     usblp_ids,
1446         .supports_autosuspend = 1,
1447 };
1448
1449 module_usb_driver(usblp_driver);
1450
1451 MODULE_AUTHOR(DRIVER_AUTHOR);
1452 MODULE_DESCRIPTION(DRIVER_DESC);
1453 module_param(proto_bias, int, S_IRUGO | S_IWUSR);
1454 MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
1455 MODULE_LICENSE("GPL");