xref: /openbmc/linux/drivers/char/lp.c (revision aac5987a)
1 /*
2  * Generic parallel printer driver
3  *
4  * Copyright (C) 1992 by Jim Weigand and Linus Torvalds
5  * Copyright (C) 1992,1993 by Michael K. Johnson
6  * - Thanks much to Gunter Windau for pointing out to me where the error
7  *   checking ought to be.
8  * Copyright (C) 1993 by Nigel Gamble (added interrupt code)
9  * Copyright (C) 1994 by Alan Cox (Modularised it)
10  * LPCAREFUL, LPABORT, LPGETSTATUS added by Chris Metcalf, metcalf@lcs.mit.edu
11  * Statistics and support for slow printers by Rob Janssen, rob@knoware.nl
12  * "lp=" command line parameters added by Grant Guenther, grant@torque.net
13  * lp_read (Status readback) support added by Carsten Gross,
14  *                                             carsten@sol.wohnheim.uni-ulm.de
15  * Support for parport by Philip Blundell <philb@gnu.org>
16  * Parport sharing hacking by Andrea Arcangeli
17  * Fixed kernel_(to/from)_user memory copy to check for errors
18  * 				by Riccardo Facchetti <fizban@tin.it>
19  * 22-JAN-1998  Added support for devfs  Richard Gooch <rgooch@atnf.csiro.au>
20  * Redesigned interrupt handling for handle printers with buggy handshake
21  *				by Andrea Arcangeli, 11 May 1998
22  * Full efficient handling of printer with buggy irq handshake (now I have
23  * understood the meaning of the strange handshake). This is done sending new
24  * characters if the interrupt is just happened, even if the printer say to
25  * be still BUSY. This is needed at least with Epson Stylus Color. To enable
26  * the new TRUST_IRQ mode read the `LP OPTIMIZATION' section below...
27  * Fixed the irq on the rising edge of the strobe case.
28  * Obsoleted the CAREFUL flag since a printer that doesn' t work with
29  * CAREFUL will block a bit after in lp_check_status().
30  *				Andrea Arcangeli, 15 Oct 1998
31  * Obsoleted and removed all the lowlevel stuff implemented in the last
32  * month to use the IEEE1284 functions (that handle the _new_ compatibilty
33  * mode fine).
34  */
35 
36 /* This driver should, in theory, work with any parallel port that has an
37  * appropriate low-level driver; all I/O is done through the parport
38  * abstraction layer.
39  *
40  * If this driver is built into the kernel, you can configure it using the
41  * kernel command-line.  For example:
42  *
43  *	lp=parport1,none,parport2	(bind lp0 to parport1, disable lp1 and
44  *					 bind lp2 to parport2)
45  *
46  *	lp=auto				(assign lp devices to all ports that
47  *				         have printers attached, as determined
48  *					 by the IEEE-1284 autoprobe)
49  *
50  *	lp=reset			(reset the printer during
51  *					 initialisation)
52  *
53  *	lp=off				(disable the printer driver entirely)
54  *
55  * If the driver is loaded as a module, similar functionality is available
56  * using module parameters.  The equivalent of the above commands would be:
57  *
58  *	# insmod lp.o parport=1,none,2
59  *
60  *	# insmod lp.o parport=auto
61  *
62  *	# insmod lp.o reset=1
63  */
64 
65 /* COMPATIBILITY WITH OLD KERNELS
66  *
67  * Under Linux 2.0 and previous versions, lp devices were bound to ports at
68  * particular I/O addresses, as follows:
69  *
70  *	lp0		0x3bc
71  *	lp1		0x378
72  *	lp2		0x278
73  *
74  * The new driver, by default, binds lp devices to parport devices as it
75  * finds them.  This means that if you only have one port, it will be bound
76  * to lp0 regardless of its I/O address.  If you need the old behaviour, you
77  * can force it using the parameters described above.
78  */
79 
80 /*
81  * The new interrupt handling code take care of the buggy handshake
82  * of some HP and Epson printer:
83  * ___
84  * ACK    _______________    ___________
85  *                       |__|
86  * ____
87  * BUSY   _________              _______
88  *                 |____________|
89  *
90  * I discovered this using the printer scanner that you can find at:
91  *
92  *	ftp://e-mind.com/pub/linux/pscan/
93  *
94  *					11 May 98, Andrea Arcangeli
95  *
96  * My printer scanner run on an Epson Stylus Color show that such printer
97  * generates the irq on the _rising_ edge of the STROBE. Now lp handle
98  * this case fine too.
99  *
100  *					15 Oct 1998, Andrea Arcangeli
101  *
102  * The so called `buggy' handshake is really the well documented
103  * compatibility mode IEEE1284 handshake. They changed the well known
104  * Centronics handshake acking in the middle of busy expecting to not
105  * break drivers or legacy application, while they broken linux lp
106  * until I fixed it reverse engineering the protocol by hand some
107  * month ago...
108  *
109  *                                     14 Dec 1998, Andrea Arcangeli
110  *
111  * Copyright (C) 2000 by Tim Waugh (added LPSETTIMEOUT ioctl)
112  */
113 
114 #include <linux/module.h>
115 #include <linux/init.h>
116 
117 #include <linux/errno.h>
118 #include <linux/kernel.h>
119 #include <linux/major.h>
120 #include <linux/sched/signal.h>
121 #include <linux/slab.h>
122 #include <linux/fcntl.h>
123 #include <linux/delay.h>
124 #include <linux/poll.h>
125 #include <linux/console.h>
126 #include <linux/device.h>
127 #include <linux/wait.h>
128 #include <linux/jiffies.h>
129 #include <linux/mutex.h>
130 #include <linux/compat.h>
131 
132 #include <linux/parport.h>
133 #undef LP_STATS
134 #include <linux/lp.h>
135 
136 #include <asm/irq.h>
137 #include <linux/uaccess.h>
138 
139 /* if you have more than 8 printers, remember to increase LP_NO */
140 #define LP_NO 8
141 
142 static DEFINE_MUTEX(lp_mutex);
143 static struct lp_struct lp_table[LP_NO];
144 
145 static unsigned int lp_count = 0;
146 static struct class *lp_class;
147 
148 #ifdef CONFIG_LP_CONSOLE
149 static struct parport *console_registered;
150 #endif /* CONFIG_LP_CONSOLE */
151 
152 #undef LP_DEBUG
153 
154 /* Bits used to manage claiming the parport device */
155 #define LP_PREEMPT_REQUEST 1
156 #define LP_PARPORT_CLAIMED 2
157 
158 /* --- low-level port access ----------------------------------- */
159 
160 #define r_dtr(x)	(parport_read_data(lp_table[(x)].dev->port))
161 #define r_str(x)	(parport_read_status(lp_table[(x)].dev->port))
162 #define w_ctr(x,y)	do { parport_write_control(lp_table[(x)].dev->port, (y)); } while (0)
163 #define w_dtr(x,y)	do { parport_write_data(lp_table[(x)].dev->port, (y)); } while (0)
164 
165 /* Claim the parport or block trying unless we've already claimed it */
166 static void lp_claim_parport_or_block(struct lp_struct *this_lp)
167 {
168 	if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
169 		parport_claim_or_block (this_lp->dev);
170 	}
171 }
172 
173 /* Claim the parport or block trying unless we've already claimed it */
174 static void lp_release_parport(struct lp_struct *this_lp)
175 {
176 	if (test_and_clear_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
177 		parport_release (this_lp->dev);
178 	}
179 }
180 
181 
182 
183 static int lp_preempt(void *handle)
184 {
185 	struct lp_struct *this_lp = (struct lp_struct *)handle;
186 	set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
187 	return (1);
188 }
189 
190 
191 /*
192  * Try to negotiate to a new mode; if unsuccessful negotiate to
193  * compatibility mode.  Return the mode we ended up in.
194  */
195 static int lp_negotiate(struct parport * port, int mode)
196 {
197 	if (parport_negotiate (port, mode) != 0) {
198 		mode = IEEE1284_MODE_COMPAT;
199 		parport_negotiate (port, mode);
200 	}
201 
202 	return (mode);
203 }
204 
205 static int lp_reset(int minor)
206 {
207 	int retval;
208 	lp_claim_parport_or_block (&lp_table[minor]);
209 	w_ctr(minor, LP_PSELECP);
210 	udelay (LP_DELAY);
211 	w_ctr(minor, LP_PSELECP | LP_PINITP);
212 	retval = r_str(minor);
213 	lp_release_parport (&lp_table[minor]);
214 	return retval;
215 }
216 
217 static void lp_error (int minor)
218 {
219 	DEFINE_WAIT(wait);
220 	int polling;
221 
222 	if (LP_F(minor) & LP_ABORT)
223 		return;
224 
225 	polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
226 	if (polling) lp_release_parport (&lp_table[minor]);
227 	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
228 	schedule_timeout(LP_TIMEOUT_POLLED);
229 	finish_wait(&lp_table[minor].waitq, &wait);
230 	if (polling) lp_claim_parport_or_block (&lp_table[minor]);
231 	else parport_yield_blocking (lp_table[minor].dev);
232 }
233 
234 static int lp_check_status(int minor)
235 {
236 	int error = 0;
237 	unsigned int last = lp_table[minor].last_error;
238 	unsigned char status = r_str(minor);
239 	if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
240 		/* No error. */
241 		last = 0;
242 	else if ((status & LP_POUTPA)) {
243 		if (last != LP_POUTPA) {
244 			last = LP_POUTPA;
245 			printk(KERN_INFO "lp%d out of paper\n", minor);
246 		}
247 		error = -ENOSPC;
248 	} else if (!(status & LP_PSELECD)) {
249 		if (last != LP_PSELECD) {
250 			last = LP_PSELECD;
251 			printk(KERN_INFO "lp%d off-line\n", minor);
252 		}
253 		error = -EIO;
254 	} else if (!(status & LP_PERRORP)) {
255 		if (last != LP_PERRORP) {
256 			last = LP_PERRORP;
257 			printk(KERN_INFO "lp%d on fire\n", minor);
258 		}
259 		error = -EIO;
260 	} else {
261 		last = 0; /* Come here if LP_CAREFUL is set and no
262                              errors are reported. */
263 	}
264 
265 	lp_table[minor].last_error = last;
266 
267 	if (last != 0)
268 		lp_error(minor);
269 
270 	return error;
271 }
272 
273 static int lp_wait_ready(int minor, int nonblock)
274 {
275 	int error = 0;
276 
277 	/* If we're not in compatibility mode, we're ready now! */
278 	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
279 	  return (0);
280 	}
281 
282 	do {
283 		error = lp_check_status (minor);
284 		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
285 			break;
286 		if (signal_pending (current)) {
287 			error = -EINTR;
288 			break;
289 		}
290 	} while (error);
291 	return error;
292 }
293 
294 static ssize_t lp_write(struct file * file, const char __user * buf,
295 		        size_t count, loff_t *ppos)
296 {
297 	unsigned int minor = iminor(file_inode(file));
298 	struct parport *port = lp_table[minor].dev->port;
299 	char *kbuf = lp_table[minor].lp_buffer;
300 	ssize_t retv = 0;
301 	ssize_t written;
302 	size_t copy_size = count;
303 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
304 			(LP_F(minor) & LP_ABORT));
305 
306 #ifdef LP_STATS
307 	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
308 		lp_table[minor].runchars = 0;
309 
310 	lp_table[minor].lastcall = jiffies;
311 #endif
312 
313 	/* Need to copy the data from user-space. */
314 	if (copy_size > LP_BUFFER_SIZE)
315 		copy_size = LP_BUFFER_SIZE;
316 
317 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
318 		return -EINTR;
319 
320 	if (copy_from_user (kbuf, buf, copy_size)) {
321 		retv = -EFAULT;
322 		goto out_unlock;
323 	}
324 
325  	/* Claim Parport or sleep until it becomes available
326  	 */
327 	lp_claim_parport_or_block (&lp_table[minor]);
328 	/* Go to the proper mode. */
329 	lp_table[minor].current_mode = lp_negotiate (port,
330 						     lp_table[minor].best_mode);
331 
332 	parport_set_timeout (lp_table[minor].dev,
333 			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
334 			      : lp_table[minor].timeout));
335 
336 	if ((retv = lp_wait_ready (minor, nonblock)) == 0)
337 	do {
338 		/* Write the data. */
339 		written = parport_write (port, kbuf, copy_size);
340 		if (written > 0) {
341 			copy_size -= written;
342 			count -= written;
343 			buf  += written;
344 			retv += written;
345 		}
346 
347 		if (signal_pending (current)) {
348 			if (retv == 0)
349 				retv = -EINTR;
350 
351 			break;
352 		}
353 
354 		if (copy_size > 0) {
355 			/* incomplete write -> check error ! */
356 			int error;
357 
358 			parport_negotiate (lp_table[minor].dev->port,
359 					   IEEE1284_MODE_COMPAT);
360 			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
361 
362 			error = lp_wait_ready (minor, nonblock);
363 
364 			if (error) {
365 				if (retv == 0)
366 					retv = error;
367 				break;
368 			} else if (nonblock) {
369 				if (retv == 0)
370 					retv = -EAGAIN;
371 				break;
372 			}
373 
374 			parport_yield_blocking (lp_table[minor].dev);
375 			lp_table[minor].current_mode
376 			  = lp_negotiate (port,
377 					  lp_table[minor].best_mode);
378 
379 		} else if (need_resched())
380 			schedule ();
381 
382 		if (count) {
383 			copy_size = count;
384 			if (copy_size > LP_BUFFER_SIZE)
385 				copy_size = LP_BUFFER_SIZE;
386 
387 			if (copy_from_user(kbuf, buf, copy_size)) {
388 				if (retv == 0)
389 					retv = -EFAULT;
390 				break;
391 			}
392 		}
393 	} while (count > 0);
394 
395 	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
396 			       &lp_table[minor].bits)) {
397 		printk(KERN_INFO "lp%d releasing parport\n", minor);
398 		parport_negotiate (lp_table[minor].dev->port,
399 				   IEEE1284_MODE_COMPAT);
400 		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
401 		lp_release_parport (&lp_table[minor]);
402 	}
403 out_unlock:
404 	mutex_unlock(&lp_table[minor].port_mutex);
405 
406  	return retv;
407 }
408 
409 #ifdef CONFIG_PARPORT_1284
410 
411 /* Status readback conforming to ieee1284 */
412 static ssize_t lp_read(struct file * file, char __user * buf,
413 		       size_t count, loff_t *ppos)
414 {
415 	DEFINE_WAIT(wait);
416 	unsigned int minor=iminor(file_inode(file));
417 	struct parport *port = lp_table[minor].dev->port;
418 	ssize_t retval = 0;
419 	char *kbuf = lp_table[minor].lp_buffer;
420 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
421 			(LP_F(minor) & LP_ABORT));
422 
423 	if (count > LP_BUFFER_SIZE)
424 		count = LP_BUFFER_SIZE;
425 
426 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
427 		return -EINTR;
428 
429 	lp_claim_parport_or_block (&lp_table[minor]);
430 
431 	parport_set_timeout (lp_table[minor].dev,
432 			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
433 			      : lp_table[minor].timeout));
434 
435 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
436 	if (parport_negotiate (lp_table[minor].dev->port,
437 			       IEEE1284_MODE_NIBBLE)) {
438 		retval = -EIO;
439 		goto out;
440 	}
441 
442 	while (retval == 0) {
443 		retval = parport_read (port, kbuf, count);
444 
445 		if (retval > 0)
446 			break;
447 
448 		if (nonblock) {
449 			retval = -EAGAIN;
450 			break;
451 		}
452 
453 		/* Wait for data. */
454 
455 		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
456 			parport_negotiate (lp_table[minor].dev->port,
457 					   IEEE1284_MODE_COMPAT);
458 			lp_error (minor);
459 			if (parport_negotiate (lp_table[minor].dev->port,
460 					       IEEE1284_MODE_NIBBLE)) {
461 				retval = -EIO;
462 				goto out;
463 			}
464 		} else {
465 			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
466 			schedule_timeout(LP_TIMEOUT_POLLED);
467 			finish_wait(&lp_table[minor].waitq, &wait);
468 		}
469 
470 		if (signal_pending (current)) {
471 			retval = -ERESTARTSYS;
472 			break;
473 		}
474 
475 		cond_resched ();
476 	}
477 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
478  out:
479 	lp_release_parport (&lp_table[minor]);
480 
481 	if (retval > 0 && copy_to_user (buf, kbuf, retval))
482 		retval = -EFAULT;
483 
484 	mutex_unlock(&lp_table[minor].port_mutex);
485 
486 	return retval;
487 }
488 
489 #endif /* IEEE 1284 support */
490 
491 static int lp_open(struct inode * inode, struct file * file)
492 {
493 	unsigned int minor = iminor(inode);
494 	int ret = 0;
495 
496 	mutex_lock(&lp_mutex);
497 	if (minor >= LP_NO) {
498 		ret = -ENXIO;
499 		goto out;
500 	}
501 	if ((LP_F(minor) & LP_EXIST) == 0) {
502 		ret = -ENXIO;
503 		goto out;
504 	}
505 	if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor))) {
506 		ret = -EBUSY;
507 		goto out;
508 	}
509 	/* If ABORTOPEN is set and the printer is offline or out of paper,
510 	   we may still want to open it to perform ioctl()s.  Therefore we
511 	   have commandeered O_NONBLOCK, even though it is being used in
512 	   a non-standard manner.  This is strictly a Linux hack, and
513 	   should most likely only ever be used by the tunelp application. */
514 	if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
515 		int status;
516 		lp_claim_parport_or_block (&lp_table[minor]);
517 		status = r_str(minor);
518 		lp_release_parport (&lp_table[minor]);
519 		if (status & LP_POUTPA) {
520 			printk(KERN_INFO "lp%d out of paper\n", minor);
521 			LP_F(minor) &= ~LP_BUSY;
522 			ret = -ENOSPC;
523 			goto out;
524 		} else if (!(status & LP_PSELECD)) {
525 			printk(KERN_INFO "lp%d off-line\n", minor);
526 			LP_F(minor) &= ~LP_BUSY;
527 			ret = -EIO;
528 			goto out;
529 		} else if (!(status & LP_PERRORP)) {
530 			printk(KERN_ERR "lp%d printer error\n", minor);
531 			LP_F(minor) &= ~LP_BUSY;
532 			ret = -EIO;
533 			goto out;
534 		}
535 	}
536 	lp_table[minor].lp_buffer = kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
537 	if (!lp_table[minor].lp_buffer) {
538 		LP_F(minor) &= ~LP_BUSY;
539 		ret = -ENOMEM;
540 		goto out;
541 	}
542 	/* Determine if the peripheral supports ECP mode */
543 	lp_claim_parport_or_block (&lp_table[minor]);
544 	if ( (lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
545              !parport_negotiate (lp_table[minor].dev->port,
546                                  IEEE1284_MODE_ECP)) {
547 		printk (KERN_INFO "lp%d: ECP mode\n", minor);
548 		lp_table[minor].best_mode = IEEE1284_MODE_ECP;
549 	} else {
550 		lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
551 	}
552 	/* Leave peripheral in compatibility mode */
553 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
554 	lp_release_parport (&lp_table[minor]);
555 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
556 out:
557 	mutex_unlock(&lp_mutex);
558 	return ret;
559 }
560 
561 static int lp_release(struct inode * inode, struct file * file)
562 {
563 	unsigned int minor = iminor(inode);
564 
565 	lp_claim_parport_or_block (&lp_table[minor]);
566 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
567 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
568 	lp_release_parport (&lp_table[minor]);
569 	kfree(lp_table[minor].lp_buffer);
570 	lp_table[minor].lp_buffer = NULL;
571 	LP_F(minor) &= ~LP_BUSY;
572 	return 0;
573 }
574 
575 static int lp_do_ioctl(unsigned int minor, unsigned int cmd,
576 	unsigned long arg, void __user *argp)
577 {
578 	int status;
579 	int retval = 0;
580 
581 #ifdef LP_DEBUG
582 	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
583 #endif
584 	if (minor >= LP_NO)
585 		return -ENODEV;
586 	if ((LP_F(minor) & LP_EXIST) == 0)
587 		return -ENODEV;
588 	switch ( cmd ) {
589 		case LPTIME:
590 			if (arg > UINT_MAX / HZ)
591 				return -EINVAL;
592 			LP_TIME(minor) = arg * HZ/100;
593 			break;
594 		case LPCHAR:
595 			LP_CHAR(minor) = arg;
596 			break;
597 		case LPABORT:
598 			if (arg)
599 				LP_F(minor) |= LP_ABORT;
600 			else
601 				LP_F(minor) &= ~LP_ABORT;
602 			break;
603 		case LPABORTOPEN:
604 			if (arg)
605 				LP_F(minor) |= LP_ABORTOPEN;
606 			else
607 				LP_F(minor) &= ~LP_ABORTOPEN;
608 			break;
609 		case LPCAREFUL:
610 			if (arg)
611 				LP_F(minor) |= LP_CAREFUL;
612 			else
613 				LP_F(minor) &= ~LP_CAREFUL;
614 			break;
615 		case LPWAIT:
616 			LP_WAIT(minor) = arg;
617 			break;
618 		case LPSETIRQ:
619 			return -EINVAL;
620 			break;
621 		case LPGETIRQ:
622 			if (copy_to_user(argp, &LP_IRQ(minor),
623 					sizeof(int)))
624 				return -EFAULT;
625 			break;
626 		case LPGETSTATUS:
627 			if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
628 				return -EINTR;
629 			lp_claim_parport_or_block (&lp_table[minor]);
630 			status = r_str(minor);
631 			lp_release_parport (&lp_table[minor]);
632 			mutex_unlock(&lp_table[minor].port_mutex);
633 
634 			if (copy_to_user(argp, &status, sizeof(int)))
635 				return -EFAULT;
636 			break;
637 		case LPRESET:
638 			lp_reset(minor);
639 			break;
640 #ifdef LP_STATS
641 		case LPGETSTATS:
642 			if (copy_to_user(argp, &LP_STAT(minor),
643 					sizeof(struct lp_stats)))
644 				return -EFAULT;
645 			if (capable(CAP_SYS_ADMIN))
646 				memset(&LP_STAT(minor), 0,
647 						sizeof(struct lp_stats));
648 			break;
649 #endif
650  		case LPGETFLAGS:
651  			status = LP_F(minor);
652 			if (copy_to_user(argp, &status, sizeof(int)))
653 				return -EFAULT;
654 			break;
655 
656 		default:
657 			retval = -EINVAL;
658 	}
659 	return retval;
660 }
661 
662 static int lp_set_timeout(unsigned int minor, struct timeval *par_timeout)
663 {
664 	long to_jiffies;
665 
666 	/* Convert to jiffies, place in lp_table */
667 	if ((par_timeout->tv_sec < 0) ||
668 	    (par_timeout->tv_usec < 0)) {
669 		return -EINVAL;
670 	}
671 	to_jiffies = DIV_ROUND_UP(par_timeout->tv_usec, 1000000/HZ);
672 	to_jiffies += par_timeout->tv_sec * (long) HZ;
673 	if (to_jiffies <= 0) {
674 		return -EINVAL;
675 	}
676 	lp_table[minor].timeout = to_jiffies;
677 	return 0;
678 }
679 
680 static long lp_ioctl(struct file *file, unsigned int cmd,
681 			unsigned long arg)
682 {
683 	unsigned int minor;
684 	struct timeval par_timeout;
685 	int ret;
686 
687 	minor = iminor(file_inode(file));
688 	mutex_lock(&lp_mutex);
689 	switch (cmd) {
690 	case LPSETTIMEOUT:
691 		if (copy_from_user(&par_timeout, (void __user *)arg,
692 					sizeof (struct timeval))) {
693 			ret = -EFAULT;
694 			break;
695 		}
696 		ret = lp_set_timeout(minor, &par_timeout);
697 		break;
698 	default:
699 		ret = lp_do_ioctl(minor, cmd, arg, (void __user *)arg);
700 		break;
701 	}
702 	mutex_unlock(&lp_mutex);
703 
704 	return ret;
705 }
706 
707 #ifdef CONFIG_COMPAT
708 static long lp_compat_ioctl(struct file *file, unsigned int cmd,
709 			unsigned long arg)
710 {
711 	unsigned int minor;
712 	struct timeval par_timeout;
713 	int ret;
714 
715 	minor = iminor(file_inode(file));
716 	mutex_lock(&lp_mutex);
717 	switch (cmd) {
718 	case LPSETTIMEOUT:
719 		if (compat_get_timeval(&par_timeout, compat_ptr(arg))) {
720 			ret = -EFAULT;
721 			break;
722 		}
723 		ret = lp_set_timeout(minor, &par_timeout);
724 		break;
725 #ifdef LP_STATS
726 	case LPGETSTATS:
727 		/* FIXME: add an implementation if you set LP_STATS */
728 		ret = -EINVAL;
729 		break;
730 #endif
731 	default:
732 		ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
733 		break;
734 	}
735 	mutex_unlock(&lp_mutex);
736 
737 	return ret;
738 }
739 #endif
740 
741 static const struct file_operations lp_fops = {
742 	.owner		= THIS_MODULE,
743 	.write		= lp_write,
744 	.unlocked_ioctl	= lp_ioctl,
745 #ifdef CONFIG_COMPAT
746 	.compat_ioctl	= lp_compat_ioctl,
747 #endif
748 	.open		= lp_open,
749 	.release	= lp_release,
750 #ifdef CONFIG_PARPORT_1284
751 	.read		= lp_read,
752 #endif
753 	.llseek		= noop_llseek,
754 };
755 
756 /* --- support for console on the line printer ----------------- */
757 
758 #ifdef CONFIG_LP_CONSOLE
759 
760 #define CONSOLE_LP 0
761 
762 /* If the printer is out of paper, we can either lose the messages or
763  * stall until the printer is happy again.  Define CONSOLE_LP_STRICT
764  * non-zero to get the latter behaviour. */
765 #define CONSOLE_LP_STRICT 1
766 
767 /* The console must be locked when we get here. */
768 
769 static void lp_console_write (struct console *co, const char *s,
770 			      unsigned count)
771 {
772 	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
773 	struct parport *port = dev->port;
774 	ssize_t written;
775 
776 	if (parport_claim (dev))
777 		/* Nothing we can do. */
778 		return;
779 
780 	parport_set_timeout (dev, 0);
781 
782 	/* Go to compatibility mode. */
783 	parport_negotiate (port, IEEE1284_MODE_COMPAT);
784 
785 	do {
786 		/* Write the data, converting LF->CRLF as we go. */
787 		ssize_t canwrite = count;
788 		char *lf = memchr (s, '\n', count);
789 		if (lf)
790 			canwrite = lf - s;
791 
792 		if (canwrite > 0) {
793 			written = parport_write (port, s, canwrite);
794 
795 			if (written <= 0)
796 				continue;
797 
798 			s += written;
799 			count -= written;
800 			canwrite -= written;
801 		}
802 
803 		if (lf && canwrite <= 0) {
804 			const char *crlf = "\r\n";
805 			int i = 2;
806 
807 			/* Dodge the original '\n', and put '\r\n' instead. */
808 			s++;
809 			count--;
810 			do {
811 				written = parport_write (port, crlf, i);
812 				if (written > 0)
813 					i -= written, crlf += written;
814 			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
815 		}
816 	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
817 
818 	parport_release (dev);
819 }
820 
821 static struct console lpcons = {
822 	.name		= "lp",
823 	.write		= lp_console_write,
824 	.flags		= CON_PRINTBUFFER,
825 };
826 
827 #endif /* console on line printer */
828 
829 /* --- initialisation code ------------------------------------- */
830 
831 static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
832 static char *parport[LP_NO];
833 static bool reset;
834 
835 module_param_array(parport, charp, NULL, 0);
836 module_param(reset, bool, 0);
837 
838 #ifndef MODULE
839 static int __init lp_setup (char *str)
840 {
841 	static int parport_ptr;
842 	int x;
843 
844 	if (get_option(&str, &x)) {
845 		if (x == 0) {
846 			/* disable driver on "lp=" or "lp=0" */
847 			parport_nr[0] = LP_PARPORT_OFF;
848 		} else {
849 			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
850 			return 0;
851 		}
852 	} else if (!strncmp(str, "parport", 7)) {
853 		int n = simple_strtoul(str+7, NULL, 10);
854 		if (parport_ptr < LP_NO)
855 			parport_nr[parport_ptr++] = n;
856 		else
857 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
858 			       str);
859 	} else if (!strcmp(str, "auto")) {
860 		parport_nr[0] = LP_PARPORT_AUTO;
861 	} else if (!strcmp(str, "none")) {
862 		parport_nr[parport_ptr++] = LP_PARPORT_NONE;
863 	} else if (!strcmp(str, "reset")) {
864 		reset = 1;
865 	}
866 	return 1;
867 }
868 #endif
869 
870 static int lp_register(int nr, struct parport *port)
871 {
872 	lp_table[nr].dev = parport_register_device(port, "lp",
873 						   lp_preempt, NULL, NULL, 0,
874 						   (void *) &lp_table[nr]);
875 	if (lp_table[nr].dev == NULL)
876 		return 1;
877 	lp_table[nr].flags |= LP_EXIST;
878 
879 	if (reset)
880 		lp_reset(nr);
881 
882 	device_create(lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
883 		      "lp%d", nr);
884 
885 	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
886 	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
887 
888 #ifdef CONFIG_LP_CONSOLE
889 	if (!nr) {
890 		if (port->modes & PARPORT_MODE_SAFEININT) {
891 			register_console(&lpcons);
892 			console_registered = port;
893 			printk (KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
894 		} else
895 			printk (KERN_ERR "lp%d: cannot run console on %s\n",
896 				CONSOLE_LP, port->name);
897 	}
898 #endif
899 
900 	return 0;
901 }
902 
903 static void lp_attach (struct parport *port)
904 {
905 	unsigned int i;
906 
907 	switch (parport_nr[0]) {
908 	case LP_PARPORT_UNSPEC:
909 	case LP_PARPORT_AUTO:
910 		if (parport_nr[0] == LP_PARPORT_AUTO &&
911 		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
912 			return;
913 		if (lp_count == LP_NO) {
914 			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
915 			return;
916 		}
917 		if (!lp_register(lp_count, port))
918 			lp_count++;
919 		break;
920 
921 	default:
922 		for (i = 0; i < LP_NO; i++) {
923 			if (port->number == parport_nr[i]) {
924 				if (!lp_register(i, port))
925 					lp_count++;
926 				break;
927 			}
928 		}
929 		break;
930 	}
931 }
932 
933 static void lp_detach (struct parport *port)
934 {
935 	/* Write this some day. */
936 #ifdef CONFIG_LP_CONSOLE
937 	if (console_registered == port) {
938 		unregister_console(&lpcons);
939 		console_registered = NULL;
940 	}
941 #endif /* CONFIG_LP_CONSOLE */
942 }
943 
944 static struct parport_driver lp_driver = {
945 	.name = "lp",
946 	.attach = lp_attach,
947 	.detach = lp_detach,
948 };
949 
950 static int __init lp_init (void)
951 {
952 	int i, err = 0;
953 
954 	if (parport_nr[0] == LP_PARPORT_OFF)
955 		return 0;
956 
957 	for (i = 0; i < LP_NO; i++) {
958 		lp_table[i].dev = NULL;
959 		lp_table[i].flags = 0;
960 		lp_table[i].chars = LP_INIT_CHAR;
961 		lp_table[i].time = LP_INIT_TIME;
962 		lp_table[i].wait = LP_INIT_WAIT;
963 		lp_table[i].lp_buffer = NULL;
964 #ifdef LP_STATS
965 		lp_table[i].lastcall = 0;
966 		lp_table[i].runchars = 0;
967 		memset (&lp_table[i].stats, 0, sizeof (struct lp_stats));
968 #endif
969 		lp_table[i].last_error = 0;
970 		init_waitqueue_head (&lp_table[i].waitq);
971 		init_waitqueue_head (&lp_table[i].dataq);
972 		mutex_init(&lp_table[i].port_mutex);
973 		lp_table[i].timeout = 10 * HZ;
974 	}
975 
976 	if (register_chrdev (LP_MAJOR, "lp", &lp_fops)) {
977 		printk (KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
978 		return -EIO;
979 	}
980 
981 	lp_class = class_create(THIS_MODULE, "printer");
982 	if (IS_ERR(lp_class)) {
983 		err = PTR_ERR(lp_class);
984 		goto out_reg;
985 	}
986 
987 	if (parport_register_driver (&lp_driver)) {
988 		printk (KERN_ERR "lp: unable to register with parport\n");
989 		err = -EIO;
990 		goto out_class;
991 	}
992 
993 	if (!lp_count) {
994 		printk (KERN_INFO "lp: driver loaded but no devices found\n");
995 #ifndef CONFIG_PARPORT_1284
996 		if (parport_nr[0] == LP_PARPORT_AUTO)
997 			printk (KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
998 #endif
999 	}
1000 
1001 	return 0;
1002 
1003 out_class:
1004 	class_destroy(lp_class);
1005 out_reg:
1006 	unregister_chrdev(LP_MAJOR, "lp");
1007 	return err;
1008 }
1009 
1010 static int __init lp_init_module (void)
1011 {
1012 	if (parport[0]) {
1013 		/* The user gave some parameters.  Let's see what they were.  */
1014 		if (!strncmp(parport[0], "auto", 4))
1015 			parport_nr[0] = LP_PARPORT_AUTO;
1016 		else {
1017 			int n;
1018 			for (n = 0; n < LP_NO && parport[n]; n++) {
1019 				if (!strncmp(parport[n], "none", 4))
1020 					parport_nr[n] = LP_PARPORT_NONE;
1021 				else {
1022 					char *ep;
1023 					unsigned long r = simple_strtoul(parport[n], &ep, 0);
1024 					if (ep != parport[n])
1025 						parport_nr[n] = r;
1026 					else {
1027 						printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
1028 						return -ENODEV;
1029 					}
1030 				}
1031 			}
1032 		}
1033 	}
1034 
1035 	return lp_init();
1036 }
1037 
1038 static void lp_cleanup_module (void)
1039 {
1040 	unsigned int offset;
1041 
1042 	parport_unregister_driver (&lp_driver);
1043 
1044 #ifdef CONFIG_LP_CONSOLE
1045 	unregister_console (&lpcons);
1046 #endif
1047 
1048 	unregister_chrdev(LP_MAJOR, "lp");
1049 	for (offset = 0; offset < LP_NO; offset++) {
1050 		if (lp_table[offset].dev == NULL)
1051 			continue;
1052 		parport_unregister_device(lp_table[offset].dev);
1053 		device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
1054 	}
1055 	class_destroy(lp_class);
1056 }
1057 
1058 __setup("lp=", lp_setup);
1059 module_init(lp_init_module);
1060 module_exit(lp_cleanup_module);
1061 
1062 MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
1063 MODULE_LICENSE("GPL");
1064