xref: /openbmc/linux/drivers/char/lp.c (revision 87c2ce3b)
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/config.h>
118 #include <linux/errno.h>
119 #include <linux/kernel.h>
120 #include <linux/major.h>
121 #include <linux/sched.h>
122 #include <linux/smp_lock.h>
123 #include <linux/devfs_fs_kernel.h>
124 #include <linux/slab.h>
125 #include <linux/fcntl.h>
126 #include <linux/delay.h>
127 #include <linux/poll.h>
128 #include <linux/console.h>
129 #include <linux/device.h>
130 #include <linux/wait.h>
131 #include <linux/jiffies.h>
132 
133 #include <linux/parport.h>
134 #undef LP_STATS
135 #include <linux/lp.h>
136 
137 #include <asm/irq.h>
138 #include <asm/uaccess.h>
139 #include <asm/system.h>
140 
141 /* if you have more than 8 printers, remember to increase LP_NO */
142 #define LP_NO 8
143 
144 /* ROUND_UP macro from fs/select.c */
145 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
146 
147 static struct lp_struct lp_table[LP_NO];
148 
149 static unsigned int lp_count = 0;
150 static struct class *lp_class;
151 
152 #ifdef CONFIG_LP_CONSOLE
153 static struct parport *console_registered; // initially NULL
154 #endif /* CONFIG_LP_CONSOLE */
155 
156 #undef LP_DEBUG
157 
158 /* Bits used to manage claiming the parport device */
159 #define LP_PREEMPT_REQUEST 1
160 #define LP_PARPORT_CLAIMED 2
161 
162 /* --- low-level port access ----------------------------------- */
163 
164 #define r_dtr(x)	(parport_read_data(lp_table[(x)].dev->port))
165 #define r_str(x)	(parport_read_status(lp_table[(x)].dev->port))
166 #define w_ctr(x,y)	do { parport_write_control(lp_table[(x)].dev->port, (y)); } while (0)
167 #define w_dtr(x,y)	do { parport_write_data(lp_table[(x)].dev->port, (y)); } while (0)
168 
169 /* Claim the parport or block trying unless we've already claimed it */
170 static void lp_claim_parport_or_block(struct lp_struct *this_lp)
171 {
172 	if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
173 		parport_claim_or_block (this_lp->dev);
174 	}
175 }
176 
177 /* Claim the parport or block trying unless we've already claimed it */
178 static void lp_release_parport(struct lp_struct *this_lp)
179 {
180 	if (test_and_clear_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
181 		parport_release (this_lp->dev);
182 	}
183 }
184 
185 
186 
187 static int lp_preempt(void *handle)
188 {
189 	struct lp_struct *this_lp = (struct lp_struct *)handle;
190 	set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
191 	return (1);
192 }
193 
194 
195 /*
196  * Try to negotiate to a new mode; if unsuccessful negotiate to
197  * compatibility mode.  Return the mode we ended up in.
198  */
199 static int lp_negotiate(struct parport * port, int mode)
200 {
201 	if (parport_negotiate (port, mode) != 0) {
202 		mode = IEEE1284_MODE_COMPAT;
203 		parport_negotiate (port, mode);
204 	}
205 
206 	return (mode);
207 }
208 
209 static int lp_reset(int minor)
210 {
211 	int retval;
212 	lp_claim_parport_or_block (&lp_table[minor]);
213 	w_ctr(minor, LP_PSELECP);
214 	udelay (LP_DELAY);
215 	w_ctr(minor, LP_PSELECP | LP_PINITP);
216 	retval = r_str(minor);
217 	lp_release_parport (&lp_table[minor]);
218 	return retval;
219 }
220 
221 static void lp_error (int minor)
222 {
223 	DEFINE_WAIT(wait);
224 	int polling;
225 
226 	if (LP_F(minor) & LP_ABORT)
227 		return;
228 
229 	polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
230 	if (polling) lp_release_parport (&lp_table[minor]);
231 	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
232 	schedule_timeout(LP_TIMEOUT_POLLED);
233 	finish_wait(&lp_table[minor].waitq, &wait);
234 	if (polling) lp_claim_parport_or_block (&lp_table[minor]);
235 	else parport_yield_blocking (lp_table[minor].dev);
236 }
237 
238 static int lp_check_status(int minor)
239 {
240 	int error = 0;
241 	unsigned int last = lp_table[minor].last_error;
242 	unsigned char status = r_str(minor);
243 	if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
244 		/* No error. */
245 		last = 0;
246 	else if ((status & LP_POUTPA)) {
247 		if (last != LP_POUTPA) {
248 			last = LP_POUTPA;
249 			printk(KERN_INFO "lp%d out of paper\n", minor);
250 		}
251 		error = -ENOSPC;
252 	} else if (!(status & LP_PSELECD)) {
253 		if (last != LP_PSELECD) {
254 			last = LP_PSELECD;
255 			printk(KERN_INFO "lp%d off-line\n", minor);
256 		}
257 		error = -EIO;
258 	} else if (!(status & LP_PERRORP)) {
259 		if (last != LP_PERRORP) {
260 			last = LP_PERRORP;
261 			printk(KERN_INFO "lp%d on fire\n", minor);
262 		}
263 		error = -EIO;
264 	} else {
265 		last = 0; /* Come here if LP_CAREFUL is set and no
266                              errors are reported. */
267 	}
268 
269 	lp_table[minor].last_error = last;
270 
271 	if (last != 0)
272 		lp_error(minor);
273 
274 	return error;
275 }
276 
277 static int lp_wait_ready(int minor, int nonblock)
278 {
279 	int error = 0;
280 
281 	/* If we're not in compatibility mode, we're ready now! */
282 	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
283 	  return (0);
284 	}
285 
286 	do {
287 		error = lp_check_status (minor);
288 		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
289 			break;
290 		if (signal_pending (current)) {
291 			error = -EINTR;
292 			break;
293 		}
294 	} while (error);
295 	return error;
296 }
297 
298 static ssize_t lp_write(struct file * file, const char __user * buf,
299 		        size_t count, loff_t *ppos)
300 {
301 	unsigned int minor = iminor(file->f_dentry->d_inode);
302 	struct parport *port = lp_table[minor].dev->port;
303 	char *kbuf = lp_table[minor].lp_buffer;
304 	ssize_t retv = 0;
305 	ssize_t written;
306 	size_t copy_size = count;
307 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
308 			(LP_F(minor) & LP_ABORT));
309 
310 #ifdef LP_STATS
311 	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
312 		lp_table[minor].runchars = 0;
313 
314 	lp_table[minor].lastcall = jiffies;
315 #endif
316 
317 	/* Need to copy the data from user-space. */
318 	if (copy_size > LP_BUFFER_SIZE)
319 		copy_size = LP_BUFFER_SIZE;
320 
321 	if (down_interruptible (&lp_table[minor].port_mutex))
322 		return -EINTR;
323 
324 	if (copy_from_user (kbuf, buf, copy_size)) {
325 		retv = -EFAULT;
326 		goto out_unlock;
327 	}
328 
329  	/* Claim Parport or sleep until it becomes available
330  	 */
331 	lp_claim_parport_or_block (&lp_table[minor]);
332 	/* Go to the proper mode. */
333 	lp_table[minor].current_mode = lp_negotiate (port,
334 						     lp_table[minor].best_mode);
335 
336 	parport_set_timeout (lp_table[minor].dev,
337 			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
338 			      : lp_table[minor].timeout));
339 
340 	if ((retv = lp_wait_ready (minor, nonblock)) == 0)
341 	do {
342 		/* Write the data. */
343 		written = parport_write (port, kbuf, copy_size);
344 		if (written > 0) {
345 			copy_size -= written;
346 			count -= written;
347 			buf  += written;
348 			retv += written;
349 		}
350 
351 		if (signal_pending (current)) {
352 			if (retv == 0)
353 				retv = -EINTR;
354 
355 			break;
356 		}
357 
358 		if (copy_size > 0) {
359 			/* incomplete write -> check error ! */
360 			int error;
361 
362 			parport_negotiate (lp_table[minor].dev->port,
363 					   IEEE1284_MODE_COMPAT);
364 			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
365 
366 			error = lp_wait_ready (minor, nonblock);
367 
368 			if (error) {
369 				if (retv == 0)
370 					retv = error;
371 				break;
372 			} else if (nonblock) {
373 				if (retv == 0)
374 					retv = -EAGAIN;
375 				break;
376 			}
377 
378 			parport_yield_blocking (lp_table[minor].dev);
379 			lp_table[minor].current_mode
380 			  = lp_negotiate (port,
381 					  lp_table[minor].best_mode);
382 
383 		} else if (need_resched())
384 			schedule ();
385 
386 		if (count) {
387 			copy_size = count;
388 			if (copy_size > LP_BUFFER_SIZE)
389 				copy_size = LP_BUFFER_SIZE;
390 
391 			if (copy_from_user(kbuf, buf, copy_size)) {
392 				if (retv == 0)
393 					retv = -EFAULT;
394 				break;
395 			}
396 		}
397 	} while (count > 0);
398 
399 	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
400 			       &lp_table[minor].bits)) {
401 		printk(KERN_INFO "lp%d releasing parport\n", minor);
402 		parport_negotiate (lp_table[minor].dev->port,
403 				   IEEE1284_MODE_COMPAT);
404 		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
405 		lp_release_parport (&lp_table[minor]);
406 	}
407 out_unlock:
408 	up (&lp_table[minor].port_mutex);
409 
410  	return retv;
411 }
412 
413 #ifdef CONFIG_PARPORT_1284
414 
415 /* Status readback conforming to ieee1284 */
416 static ssize_t lp_read(struct file * file, char __user * buf,
417 		       size_t count, loff_t *ppos)
418 {
419 	DEFINE_WAIT(wait);
420 	unsigned int minor=iminor(file->f_dentry->d_inode);
421 	struct parport *port = lp_table[minor].dev->port;
422 	ssize_t retval = 0;
423 	char *kbuf = lp_table[minor].lp_buffer;
424 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
425 			(LP_F(minor) & LP_ABORT));
426 
427 	if (count > LP_BUFFER_SIZE)
428 		count = LP_BUFFER_SIZE;
429 
430 	if (down_interruptible (&lp_table[minor].port_mutex))
431 		return -EINTR;
432 
433 	lp_claim_parport_or_block (&lp_table[minor]);
434 
435 	parport_set_timeout (lp_table[minor].dev,
436 			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
437 			      : lp_table[minor].timeout));
438 
439 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
440 	if (parport_negotiate (lp_table[minor].dev->port,
441 			       IEEE1284_MODE_NIBBLE)) {
442 		retval = -EIO;
443 		goto out;
444 	}
445 
446 	while (retval == 0) {
447 		retval = parport_read (port, kbuf, count);
448 
449 		if (retval > 0)
450 			break;
451 
452 		if (nonblock) {
453 			retval = -EAGAIN;
454 			break;
455 		}
456 
457 		/* Wait for data. */
458 
459 		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
460 			parport_negotiate (lp_table[minor].dev->port,
461 					   IEEE1284_MODE_COMPAT);
462 			lp_error (minor);
463 			if (parport_negotiate (lp_table[minor].dev->port,
464 					       IEEE1284_MODE_NIBBLE)) {
465 				retval = -EIO;
466 				goto out;
467 			}
468 		} else {
469 			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
470 			schedule_timeout(LP_TIMEOUT_POLLED);
471 			finish_wait(&lp_table[minor].waitq, &wait);
472 		}
473 
474 		if (signal_pending (current)) {
475 			retval = -ERESTARTSYS;
476 			break;
477 		}
478 
479 		cond_resched ();
480 	}
481 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
482  out:
483 	lp_release_parport (&lp_table[minor]);
484 
485 	if (retval > 0 && copy_to_user (buf, kbuf, retval))
486 		retval = -EFAULT;
487 
488 	up (&lp_table[minor].port_mutex);
489 
490 	return retval;
491 }
492 
493 #endif /* IEEE 1284 support */
494 
495 static int lp_open(struct inode * inode, struct file * file)
496 {
497 	unsigned int minor = iminor(inode);
498 
499 	if (minor >= LP_NO)
500 		return -ENXIO;
501 	if ((LP_F(minor) & LP_EXIST) == 0)
502 		return -ENXIO;
503 	if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor)))
504 		return -EBUSY;
505 
506 	/* If ABORTOPEN is set and the printer is offline or out of paper,
507 	   we may still want to open it to perform ioctl()s.  Therefore we
508 	   have commandeered O_NONBLOCK, even though it is being used in
509 	   a non-standard manner.  This is strictly a Linux hack, and
510 	   should most likely only ever be used by the tunelp application. */
511 	if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
512 		int status;
513 		lp_claim_parport_or_block (&lp_table[minor]);
514 		status = r_str(minor);
515 		lp_release_parport (&lp_table[minor]);
516 		if (status & LP_POUTPA) {
517 			printk(KERN_INFO "lp%d out of paper\n", minor);
518 			LP_F(minor) &= ~LP_BUSY;
519 			return -ENOSPC;
520 		} else if (!(status & LP_PSELECD)) {
521 			printk(KERN_INFO "lp%d off-line\n", minor);
522 			LP_F(minor) &= ~LP_BUSY;
523 			return -EIO;
524 		} else if (!(status & LP_PERRORP)) {
525 			printk(KERN_ERR "lp%d printer error\n", minor);
526 			LP_F(minor) &= ~LP_BUSY;
527 			return -EIO;
528 		}
529 	}
530 	lp_table[minor].lp_buffer = (char *) kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
531 	if (!lp_table[minor].lp_buffer) {
532 		LP_F(minor) &= ~LP_BUSY;
533 		return -ENOMEM;
534 	}
535 	/* Determine if the peripheral supports ECP mode */
536 	lp_claim_parport_or_block (&lp_table[minor]);
537 	if ( (lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
538              !parport_negotiate (lp_table[minor].dev->port,
539                                  IEEE1284_MODE_ECP)) {
540 		printk (KERN_INFO "lp%d: ECP mode\n", minor);
541 		lp_table[minor].best_mode = IEEE1284_MODE_ECP;
542 	} else {
543 		lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
544 	}
545 	/* Leave peripheral in compatibility mode */
546 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
547 	lp_release_parport (&lp_table[minor]);
548 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
549 	return 0;
550 }
551 
552 static int lp_release(struct inode * inode, struct file * file)
553 {
554 	unsigned int minor = iminor(inode);
555 
556 	lp_claim_parport_or_block (&lp_table[minor]);
557 	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
558 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
559 	lp_release_parport (&lp_table[minor]);
560 	kfree(lp_table[minor].lp_buffer);
561 	lp_table[minor].lp_buffer = NULL;
562 	LP_F(minor) &= ~LP_BUSY;
563 	return 0;
564 }
565 
566 static int lp_ioctl(struct inode *inode, struct file *file,
567 		    unsigned int cmd, unsigned long arg)
568 {
569 	unsigned int minor = iminor(inode);
570 	int status;
571 	int retval = 0;
572 	void __user *argp = (void __user *)arg;
573 
574 #ifdef LP_DEBUG
575 	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
576 #endif
577 	if (minor >= LP_NO)
578 		return -ENODEV;
579 	if ((LP_F(minor) & LP_EXIST) == 0)
580 		return -ENODEV;
581 	switch ( cmd ) {
582 		struct timeval par_timeout;
583 		long to_jiffies;
584 
585 		case LPTIME:
586 			LP_TIME(minor) = arg * HZ/100;
587 			break;
588 		case LPCHAR:
589 			LP_CHAR(minor) = arg;
590 			break;
591 		case LPABORT:
592 			if (arg)
593 				LP_F(minor) |= LP_ABORT;
594 			else
595 				LP_F(minor) &= ~LP_ABORT;
596 			break;
597 		case LPABORTOPEN:
598 			if (arg)
599 				LP_F(minor) |= LP_ABORTOPEN;
600 			else
601 				LP_F(minor) &= ~LP_ABORTOPEN;
602 			break;
603 		case LPCAREFUL:
604 			if (arg)
605 				LP_F(minor) |= LP_CAREFUL;
606 			else
607 				LP_F(minor) &= ~LP_CAREFUL;
608 			break;
609 		case LPWAIT:
610 			LP_WAIT(minor) = arg;
611 			break;
612 		case LPSETIRQ:
613 			return -EINVAL;
614 			break;
615 		case LPGETIRQ:
616 			if (copy_to_user(argp, &LP_IRQ(minor),
617 					sizeof(int)))
618 				return -EFAULT;
619 			break;
620 		case LPGETSTATUS:
621 			lp_claim_parport_or_block (&lp_table[minor]);
622 			status = r_str(minor);
623 			lp_release_parport (&lp_table[minor]);
624 
625 			if (copy_to_user(argp, &status, sizeof(int)))
626 				return -EFAULT;
627 			break;
628 		case LPRESET:
629 			lp_reset(minor);
630 			break;
631 #ifdef LP_STATS
632 		case LPGETSTATS:
633 			if (copy_to_user(argp, &LP_STAT(minor),
634 					sizeof(struct lp_stats)))
635 				return -EFAULT;
636 			if (capable(CAP_SYS_ADMIN))
637 				memset(&LP_STAT(minor), 0,
638 						sizeof(struct lp_stats));
639 			break;
640 #endif
641  		case LPGETFLAGS:
642  			status = LP_F(minor);
643 			if (copy_to_user(argp, &status, sizeof(int)))
644 				return -EFAULT;
645 			break;
646 
647 		case LPSETTIMEOUT:
648 			if (copy_from_user (&par_timeout, argp,
649 					    sizeof (struct timeval))) {
650 				return -EFAULT;
651 			}
652 			/* Convert to jiffies, place in lp_table */
653 			if ((par_timeout.tv_sec < 0) ||
654 			    (par_timeout.tv_usec < 0)) {
655 				return -EINVAL;
656 			}
657 			to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
658 			to_jiffies += par_timeout.tv_sec * (long) HZ;
659 			if (to_jiffies <= 0) {
660 				return -EINVAL;
661 			}
662 			lp_table[minor].timeout = to_jiffies;
663 			break;
664 
665 		default:
666 			retval = -EINVAL;
667 	}
668 	return retval;
669 }
670 
671 static struct file_operations lp_fops = {
672 	.owner		= THIS_MODULE,
673 	.write		= lp_write,
674 	.ioctl		= lp_ioctl,
675 	.open		= lp_open,
676 	.release	= lp_release,
677 #ifdef CONFIG_PARPORT_1284
678 	.read		= lp_read,
679 #endif
680 };
681 
682 /* --- support for console on the line printer ----------------- */
683 
684 #ifdef CONFIG_LP_CONSOLE
685 
686 #define CONSOLE_LP 0
687 
688 /* If the printer is out of paper, we can either lose the messages or
689  * stall until the printer is happy again.  Define CONSOLE_LP_STRICT
690  * non-zero to get the latter behaviour. */
691 #define CONSOLE_LP_STRICT 1
692 
693 /* The console must be locked when we get here. */
694 
695 static void lp_console_write (struct console *co, const char *s,
696 			      unsigned count)
697 {
698 	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
699 	struct parport *port = dev->port;
700 	ssize_t written;
701 
702 	if (parport_claim (dev))
703 		/* Nothing we can do. */
704 		return;
705 
706 	parport_set_timeout (dev, 0);
707 
708 	/* Go to compatibility mode. */
709 	parport_negotiate (port, IEEE1284_MODE_COMPAT);
710 
711 	do {
712 		/* Write the data, converting LF->CRLF as we go. */
713 		ssize_t canwrite = count;
714 		char *lf = memchr (s, '\n', count);
715 		if (lf)
716 			canwrite = lf - s;
717 
718 		if (canwrite > 0) {
719 			written = parport_write (port, s, canwrite);
720 
721 			if (written <= 0)
722 				continue;
723 
724 			s += written;
725 			count -= written;
726 			canwrite -= written;
727 		}
728 
729 		if (lf && canwrite <= 0) {
730 			const char *crlf = "\r\n";
731 			int i = 2;
732 
733 			/* Dodge the original '\n', and put '\r\n' instead. */
734 			s++;
735 			count--;
736 			do {
737 				written = parport_write (port, crlf, i);
738 				if (written > 0)
739 					i -= written, crlf += written;
740 			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
741 		}
742 	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
743 
744 	parport_release (dev);
745 }
746 
747 static struct console lpcons = {
748 	.name		= "lp",
749 	.write		= lp_console_write,
750 	.flags		= CON_PRINTBUFFER,
751 };
752 
753 #endif /* console on line printer */
754 
755 /* --- initialisation code ------------------------------------- */
756 
757 static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
758 static char *parport[LP_NO] = { NULL,  };
759 static int reset = 0;
760 
761 module_param_array(parport, charp, NULL, 0);
762 module_param(reset, bool, 0);
763 
764 #ifndef MODULE
765 static int __init lp_setup (char *str)
766 {
767 	static int parport_ptr; // initially zero
768 	int x;
769 
770 	if (get_option (&str, &x)) {
771 		if (x == 0) {
772 			/* disable driver on "lp=" or "lp=0" */
773 			parport_nr[0] = LP_PARPORT_OFF;
774 		} else {
775 			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
776 			return 0;
777 		}
778 	} else if (!strncmp(str, "parport", 7)) {
779 		int n = simple_strtoul(str+7, NULL, 10);
780 		if (parport_ptr < LP_NO)
781 			parport_nr[parport_ptr++] = n;
782 		else
783 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
784 			       str);
785 	} else if (!strcmp(str, "auto")) {
786 		parport_nr[0] = LP_PARPORT_AUTO;
787 	} else if (!strcmp(str, "none")) {
788 		parport_nr[parport_ptr++] = LP_PARPORT_NONE;
789 	} else if (!strcmp(str, "reset")) {
790 		reset = 1;
791 	}
792 	return 1;
793 }
794 #endif
795 
796 static int lp_register(int nr, struct parport *port)
797 {
798 	lp_table[nr].dev = parport_register_device(port, "lp",
799 						   lp_preempt, NULL, NULL, 0,
800 						   (void *) &lp_table[nr]);
801 	if (lp_table[nr].dev == NULL)
802 		return 1;
803 	lp_table[nr].flags |= LP_EXIST;
804 
805 	if (reset)
806 		lp_reset(nr);
807 
808 	class_device_create(lp_class, NULL, MKDEV(LP_MAJOR, nr), NULL,
809 				"lp%d", nr);
810 	devfs_mk_cdev(MKDEV(LP_MAJOR, nr), S_IFCHR | S_IRUGO | S_IWUGO,
811 			"printers/%d", nr);
812 
813 	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
814 	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
815 
816 #ifdef CONFIG_LP_CONSOLE
817 	if (!nr) {
818 		if (port->modes & PARPORT_MODE_SAFEININT) {
819 			register_console (&lpcons);
820 			console_registered = port;
821 			printk (KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
822 		} else
823 			printk (KERN_ERR "lp%d: cannot run console on %s\n",
824 				CONSOLE_LP, port->name);
825 	}
826 #endif
827 
828 	return 0;
829 }
830 
831 static void lp_attach (struct parport *port)
832 {
833 	unsigned int i;
834 
835 	switch (parport_nr[0])
836 	{
837 	case LP_PARPORT_UNSPEC:
838 	case LP_PARPORT_AUTO:
839 		if (parport_nr[0] == LP_PARPORT_AUTO &&
840 		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
841 			return;
842 		if (lp_count == LP_NO) {
843 			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
844 			return;
845 		}
846 		if (!lp_register(lp_count, port))
847 			lp_count++;
848 		break;
849 
850 	default:
851 		for (i = 0; i < LP_NO; i++) {
852 			if (port->number == parport_nr[i]) {
853 				if (!lp_register(i, port))
854 					lp_count++;
855 				break;
856 			}
857 		}
858 		break;
859 	}
860 }
861 
862 static void lp_detach (struct parport *port)
863 {
864 	/* Write this some day. */
865 #ifdef CONFIG_LP_CONSOLE
866 	if (console_registered == port) {
867 		unregister_console (&lpcons);
868 		console_registered = NULL;
869 	}
870 #endif /* CONFIG_LP_CONSOLE */
871 }
872 
873 static struct parport_driver lp_driver = {
874 	.name = "lp",
875 	.attach = lp_attach,
876 	.detach = lp_detach,
877 };
878 
879 static int __init lp_init (void)
880 {
881 	int i, err = 0;
882 
883 	if (parport_nr[0] == LP_PARPORT_OFF)
884 		return 0;
885 
886 	for (i = 0; i < LP_NO; i++) {
887 		lp_table[i].dev = NULL;
888 		lp_table[i].flags = 0;
889 		lp_table[i].chars = LP_INIT_CHAR;
890 		lp_table[i].time = LP_INIT_TIME;
891 		lp_table[i].wait = LP_INIT_WAIT;
892 		lp_table[i].lp_buffer = NULL;
893 #ifdef LP_STATS
894 		lp_table[i].lastcall = 0;
895 		lp_table[i].runchars = 0;
896 		memset (&lp_table[i].stats, 0, sizeof (struct lp_stats));
897 #endif
898 		lp_table[i].last_error = 0;
899 		init_waitqueue_head (&lp_table[i].waitq);
900 		init_waitqueue_head (&lp_table[i].dataq);
901 		init_MUTEX (&lp_table[i].port_mutex);
902 		lp_table[i].timeout = 10 * HZ;
903 	}
904 
905 	if (register_chrdev (LP_MAJOR, "lp", &lp_fops)) {
906 		printk (KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
907 		return -EIO;
908 	}
909 
910 	devfs_mk_dir("printers");
911 	lp_class = class_create(THIS_MODULE, "printer");
912 	if (IS_ERR(lp_class)) {
913 		err = PTR_ERR(lp_class);
914 		goto out_devfs;
915 	}
916 
917 	if (parport_register_driver (&lp_driver)) {
918 		printk (KERN_ERR "lp: unable to register with parport\n");
919 		err = -EIO;
920 		goto out_class;
921 	}
922 
923 	if (!lp_count) {
924 		printk (KERN_INFO "lp: driver loaded but no devices found\n");
925 #ifndef CONFIG_PARPORT_1284
926 		if (parport_nr[0] == LP_PARPORT_AUTO)
927 			printk (KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
928 #endif
929 	}
930 
931 	return 0;
932 
933 out_class:
934 	class_destroy(lp_class);
935 out_devfs:
936 	devfs_remove("printers");
937 	unregister_chrdev(LP_MAJOR, "lp");
938 	return err;
939 }
940 
941 static int __init lp_init_module (void)
942 {
943 	if (parport[0]) {
944 		/* The user gave some parameters.  Let's see what they were.  */
945 		if (!strncmp(parport[0], "auto", 4))
946 			parport_nr[0] = LP_PARPORT_AUTO;
947 		else {
948 			int n;
949 			for (n = 0; n < LP_NO && parport[n]; n++) {
950 				if (!strncmp(parport[n], "none", 4))
951 					parport_nr[n] = LP_PARPORT_NONE;
952 				else {
953 					char *ep;
954 					unsigned long r = simple_strtoul(parport[n], &ep, 0);
955 					if (ep != parport[n])
956 						parport_nr[n] = r;
957 					else {
958 						printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
959 						return -ENODEV;
960 					}
961 				}
962 			}
963 		}
964 	}
965 
966 	return lp_init();
967 }
968 
969 static void lp_cleanup_module (void)
970 {
971 	unsigned int offset;
972 
973 	parport_unregister_driver (&lp_driver);
974 
975 #ifdef CONFIG_LP_CONSOLE
976 	unregister_console (&lpcons);
977 #endif
978 
979 	unregister_chrdev(LP_MAJOR, "lp");
980 	for (offset = 0; offset < LP_NO; offset++) {
981 		if (lp_table[offset].dev == NULL)
982 			continue;
983 		parport_unregister_device(lp_table[offset].dev);
984 		devfs_remove("printers/%d", offset);
985 		class_device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
986 	}
987 	devfs_remove("printers");
988 	class_destroy(lp_class);
989 }
990 
991 __setup("lp=", lp_setup);
992 module_init(lp_init_module);
993 module_exit(lp_cleanup_module);
994 
995 MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
996 MODULE_LICENSE("GPL");
997