1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic parallel printer driver
4  *
5  * Copyright (C) 1992 by Jim Weigand and Linus Torvalds
6  * Copyright (C) 1992,1993 by Michael K. Johnson
7  * - Thanks much to Gunter Windau for pointing out to me where the error
8  *   checking ought to be.
9  * Copyright (C) 1993 by Nigel Gamble (added interrupt code)
10  * Copyright (C) 1994 by Alan Cox (Modularised it)
11  * LPCAREFUL, LPABORT, LPGETSTATUS added by Chris Metcalf, metcalf@lcs.mit.edu
12  * Statistics and support for slow printers by Rob Janssen, rob@knoware.nl
13  * "lp=" command line parameters added by Grant Guenther, grant@torque.net
14  * lp_read (Status readback) support added by Carsten Gross,
15  *                                             carsten@sol.wohnheim.uni-ulm.de
16  * Support for parport by Philip Blundell <philb@gnu.org>
17  * Parport sharing hacking by Andrea Arcangeli
18  * Fixed kernel_(to/from)_user memory copy to check for errors
19  * 				by Riccardo Facchetti <fizban@tin.it>
20  * 22-JAN-1998  Added support for devfs  Richard Gooch <rgooch@atnf.csiro.au>
21  * Redesigned interrupt handling for handle printers with buggy handshake
22  *				by Andrea Arcangeli, 11 May 1998
23  * Full efficient handling of printer with buggy irq handshake (now I have
24  * understood the meaning of the strange handshake). This is done sending new
25  * characters if the interrupt is just happened, even if the printer say to
26  * be still BUSY. This is needed at least with Epson Stylus Color. To enable
27  * the new TRUST_IRQ mode read the `LP OPTIMIZATION' section below...
28  * Fixed the irq on the rising edge of the strobe case.
29  * Obsoleted the CAREFUL flag since a printer that doesn' t work with
30  * CAREFUL will block a bit after in lp_check_status().
31  *				Andrea Arcangeli, 15 Oct 1998
32  * Obsoleted and removed all the lowlevel stuff implemented in the last
33  * month to use the IEEE1284 functions (that handle the _new_ compatibilty
34  * mode fine).
35  */
36 
37 /* This driver should, in theory, work with any parallel port that has an
38  * appropriate low-level driver; all I/O is done through the parport
39  * abstraction layer.
40  *
41  * If this driver is built into the kernel, you can configure it using the
42  * kernel command-line.  For example:
43  *
44  *	lp=parport1,none,parport2	(bind lp0 to parport1, disable lp1 and
45  *					 bind lp2 to parport2)
46  *
47  *	lp=auto				(assign lp devices to all ports that
48  *				         have printers attached, as determined
49  *					 by the IEEE-1284 autoprobe)
50  *
51  *	lp=reset			(reset the printer during
52  *					 initialisation)
53  *
54  *	lp=off				(disable the printer driver entirely)
55  *
56  * If the driver is loaded as a module, similar functionality is available
57  * using module parameters.  The equivalent of the above commands would be:
58  *
59  *	# insmod lp.o parport=1,none,2
60  *
61  *	# insmod lp.o parport=auto
62  *
63  *	# insmod lp.o reset=1
64  */
65 
66 /* COMPATIBILITY WITH OLD KERNELS
67  *
68  * Under Linux 2.0 and previous versions, lp devices were bound to ports at
69  * particular I/O addresses, as follows:
70  *
71  *	lp0		0x3bc
72  *	lp1		0x378
73  *	lp2		0x278
74  *
75  * The new driver, by default, binds lp devices to parport devices as it
76  * finds them.  This means that if you only have one port, it will be bound
77  * to lp0 regardless of its I/O address.  If you need the old behaviour, you
78  * can force it using the parameters described above.
79  */
80 
81 /*
82  * The new interrupt handling code take care of the buggy handshake
83  * of some HP and Epson printer:
84  * ___
85  * ACK    _______________    ___________
86  *                       |__|
87  * ____
88  * BUSY   _________              _______
89  *                 |____________|
90  *
91  * I discovered this using the printer scanner that you can find at:
92  *
93  *	ftp://e-mind.com/pub/linux/pscan/
94  *
95  *					11 May 98, Andrea Arcangeli
96  *
97  * My printer scanner run on an Epson Stylus Color show that such printer
98  * generates the irq on the _rising_ edge of the STROBE. Now lp handle
99  * this case fine too.
100  *
101  *					15 Oct 1998, Andrea Arcangeli
102  *
103  * The so called `buggy' handshake is really the well documented
104  * compatibility mode IEEE1284 handshake. They changed the well known
105  * Centronics handshake acking in the middle of busy expecting to not
106  * break drivers or legacy application, while they broken linux lp
107  * until I fixed it reverse engineering the protocol by hand some
108  * month ago...
109  *
110  *                                     14 Dec 1998, Andrea Arcangeli
111  *
112  * Copyright (C) 2000 by Tim Waugh (added LPSETTIMEOUT ioctl)
113  */
114 
115 #include <linux/module.h>
116 #include <linux/init.h>
117 
118 #include <linux/errno.h>
119 #include <linux/kernel.h>
120 #include <linux/major.h>
121 #include <linux/sched/signal.h>
122 #include <linux/slab.h>
123 #include <linux/fcntl.h>
124 #include <linux/delay.h>
125 #include <linux/poll.h>
126 #include <linux/console.h>
127 #include <linux/device.h>
128 #include <linux/wait.h>
129 #include <linux/jiffies.h>
130 #include <linux/mutex.h>
131 #include <linux/compat.h>
132 
133 #include <linux/parport.h>
134 #undef LP_STATS
135 #include <linux/lp.h>
136 
137 #include <asm/irq.h>
138 #include <linux/uaccess.h>
139 
140 /* if you have more than 8 printers, remember to increase LP_NO */
141 #define LP_NO 8
142 
143 static DEFINE_MUTEX(lp_mutex);
144 static struct lp_struct lp_table[LP_NO];
145 static int port_num[LP_NO];
146 
147 static unsigned int lp_count = 0;
148 static struct class *lp_class;
149 
150 #ifdef CONFIG_LP_CONSOLE
151 static struct parport *console_registered;
152 #endif /* CONFIG_LP_CONSOLE */
153 
154 #undef LP_DEBUG
155 
156 /* Bits used to manage claiming the parport device */
157 #define LP_PREEMPT_REQUEST 1
158 #define LP_PARPORT_CLAIMED 2
159 
160 /* --- low-level port access ----------------------------------- */
161 
162 #define r_dtr(x)	(parport_read_data(lp_table[(x)].dev->port))
163 #define r_str(x)	(parport_read_status(lp_table[(x)].dev->port))
164 #define w_ctr(x,y)	do { parport_write_control(lp_table[(x)].dev->port, (y)); } while (0)
165 #define w_dtr(x,y)	do { parport_write_data(lp_table[(x)].dev->port, (y)); } while (0)
166 
167 /* Claim the parport or block trying unless we've already claimed it */
lp_claim_parport_or_block(struct lp_struct * this_lp)168 static void lp_claim_parport_or_block(struct lp_struct *this_lp)
169 {
170 	if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
171 		parport_claim_or_block(this_lp->dev);
172 	}
173 }
174 
175 /* Claim the parport or block trying unless we've already claimed it */
lp_release_parport(struct lp_struct * this_lp)176 static void lp_release_parport(struct lp_struct *this_lp)
177 {
178 	if (test_and_clear_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
179 		parport_release(this_lp->dev);
180 	}
181 }
182 
183 
184 
lp_preempt(void * handle)185 static int lp_preempt(void *handle)
186 {
187 	struct lp_struct *this_lp = (struct lp_struct *)handle;
188 	set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
189 	return 1;
190 }
191 
192 
193 /*
194  * Try to negotiate to a new mode; if unsuccessful negotiate to
195  * compatibility mode.  Return the mode we ended up in.
196  */
lp_negotiate(struct parport * port,int mode)197 static int lp_negotiate(struct parport *port, int mode)
198 {
199 	if (parport_negotiate(port, mode) != 0) {
200 		mode = IEEE1284_MODE_COMPAT;
201 		parport_negotiate(port, mode);
202 	}
203 
204 	return mode;
205 }
206 
lp_reset(int minor)207 static int lp_reset(int minor)
208 {
209 	int retval;
210 	lp_claim_parport_or_block(&lp_table[minor]);
211 	w_ctr(minor, LP_PSELECP);
212 	udelay(LP_DELAY);
213 	w_ctr(minor, LP_PSELECP | LP_PINITP);
214 	retval = r_str(minor);
215 	lp_release_parport(&lp_table[minor]);
216 	return retval;
217 }
218 
lp_error(int minor)219 static void lp_error(int minor)
220 {
221 	DEFINE_WAIT(wait);
222 	int polling;
223 
224 	if (LP_F(minor) & LP_ABORT)
225 		return;
226 
227 	polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
228 	if (polling)
229 		lp_release_parport(&lp_table[minor]);
230 	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
231 	schedule_timeout(LP_TIMEOUT_POLLED);
232 	finish_wait(&lp_table[minor].waitq, &wait);
233 	if (polling)
234 		lp_claim_parport_or_block(&lp_table[minor]);
235 	else
236 		parport_yield_blocking(lp_table[minor].dev);
237 }
238 
lp_check_status(int minor)239 static int lp_check_status(int minor)
240 {
241 	int error = 0;
242 	unsigned int last = lp_table[minor].last_error;
243 	unsigned char status = r_str(minor);
244 	if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
245 		/* No error. */
246 		last = 0;
247 	else if ((status & LP_POUTPA)) {
248 		if (last != LP_POUTPA) {
249 			last = LP_POUTPA;
250 			printk(KERN_INFO "lp%d out of paper\n", minor);
251 		}
252 		error = -ENOSPC;
253 	} else if (!(status & LP_PSELECD)) {
254 		if (last != LP_PSELECD) {
255 			last = LP_PSELECD;
256 			printk(KERN_INFO "lp%d off-line\n", minor);
257 		}
258 		error = -EIO;
259 	} else if (!(status & LP_PERRORP)) {
260 		if (last != LP_PERRORP) {
261 			last = LP_PERRORP;
262 			printk(KERN_INFO "lp%d on fire\n", minor);
263 		}
264 		error = -EIO;
265 	} else {
266 		last = 0; /* Come here if LP_CAREFUL is set and no
267 			     errors are reported. */
268 	}
269 
270 	lp_table[minor].last_error = last;
271 
272 	if (last != 0)
273 		lp_error(minor);
274 
275 	return error;
276 }
277 
lp_wait_ready(int minor,int nonblock)278 static int lp_wait_ready(int minor, int nonblock)
279 {
280 	int error = 0;
281 
282 	/* If we're not in compatibility mode, we're ready now! */
283 	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
284 		return 0;
285 	}
286 
287 	do {
288 		error = lp_check_status(minor);
289 		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
290 			break;
291 		if (signal_pending(current)) {
292 			error = -EINTR;
293 			break;
294 		}
295 	} while (error);
296 	return error;
297 }
298 
lp_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)299 static ssize_t lp_write(struct file *file, const char __user *buf,
300 			size_t count, loff_t *ppos)
301 {
302 	unsigned int minor = iminor(file_inode(file));
303 	struct parport *port = lp_table[minor].dev->port;
304 	char *kbuf = lp_table[minor].lp_buffer;
305 	ssize_t retv = 0;
306 	ssize_t written;
307 	size_t copy_size = count;
308 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
309 			(LP_F(minor) & LP_ABORT));
310 
311 #ifdef LP_STATS
312 	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
313 		lp_table[minor].runchars = 0;
314 
315 	lp_table[minor].lastcall = jiffies;
316 #endif
317 
318 	/* Need to copy the data from user-space. */
319 	if (copy_size > LP_BUFFER_SIZE)
320 		copy_size = LP_BUFFER_SIZE;
321 
322 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
323 		return -EINTR;
324 
325 	if (copy_from_user(kbuf, buf, copy_size)) {
326 		retv = -EFAULT;
327 		goto out_unlock;
328 	}
329 
330 	/* Claim Parport or sleep until it becomes available
331 	 */
332 	lp_claim_parport_or_block(&lp_table[minor]);
333 	/* Go to the proper mode. */
334 	lp_table[minor].current_mode = lp_negotiate(port,
335 						    lp_table[minor].best_mode);
336 
337 	parport_set_timeout(lp_table[minor].dev,
338 			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
339 			     : lp_table[minor].timeout));
340 
341 	if ((retv = lp_wait_ready(minor, nonblock)) == 0)
342 	do {
343 		/* Write the data. */
344 		written = parport_write(port, kbuf, copy_size);
345 		if (written > 0) {
346 			copy_size -= written;
347 			count -= written;
348 			buf  += written;
349 			retv += written;
350 		}
351 
352 		if (signal_pending(current)) {
353 			if (retv == 0)
354 				retv = -EINTR;
355 
356 			break;
357 		}
358 
359 		if (copy_size > 0) {
360 			/* incomplete write -> check error ! */
361 			int error;
362 
363 			parport_negotiate(lp_table[minor].dev->port,
364 					  IEEE1284_MODE_COMPAT);
365 			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
366 
367 			error = lp_wait_ready(minor, nonblock);
368 
369 			if (error) {
370 				if (retv == 0)
371 					retv = error;
372 				break;
373 			} else if (nonblock) {
374 				if (retv == 0)
375 					retv = -EAGAIN;
376 				break;
377 			}
378 
379 			parport_yield_blocking(lp_table[minor].dev);
380 			lp_table[minor].current_mode
381 			  = lp_negotiate(port,
382 					 lp_table[minor].best_mode);
383 
384 		} else if (need_resched())
385 			schedule();
386 
387 		if (count) {
388 			copy_size = count;
389 			if (copy_size > LP_BUFFER_SIZE)
390 				copy_size = LP_BUFFER_SIZE;
391 
392 			if (copy_from_user(kbuf, buf, copy_size)) {
393 				if (retv == 0)
394 					retv = -EFAULT;
395 				break;
396 			}
397 		}
398 	} while (count > 0);
399 
400 	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
401 			       &lp_table[minor].bits)) {
402 		printk(KERN_INFO "lp%d releasing parport\n", minor);
403 		parport_negotiate(lp_table[minor].dev->port,
404 				  IEEE1284_MODE_COMPAT);
405 		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
406 		lp_release_parport(&lp_table[minor]);
407 	}
408 out_unlock:
409 	mutex_unlock(&lp_table[minor].port_mutex);
410 
411 	return retv;
412 }
413 
414 #ifdef CONFIG_PARPORT_1284
415 
416 /* Status readback conforming to ieee1284 */
lp_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)417 static ssize_t lp_read(struct file *file, char __user *buf,
418 		       size_t count, loff_t *ppos)
419 {
420 	DEFINE_WAIT(wait);
421 	unsigned int minor=iminor(file_inode(file));
422 	struct parport *port = lp_table[minor].dev->port;
423 	ssize_t retval = 0;
424 	char *kbuf = lp_table[minor].lp_buffer;
425 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
426 			(LP_F(minor) & LP_ABORT));
427 
428 	if (count > LP_BUFFER_SIZE)
429 		count = LP_BUFFER_SIZE;
430 
431 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
432 		return -EINTR;
433 
434 	lp_claim_parport_or_block(&lp_table[minor]);
435 
436 	parport_set_timeout(lp_table[minor].dev,
437 			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
438 			     : lp_table[minor].timeout));
439 
440 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
441 	if (parport_negotiate(lp_table[minor].dev->port,
442 			      IEEE1284_MODE_NIBBLE)) {
443 		retval = -EIO;
444 		goto out;
445 	}
446 
447 	while (retval == 0) {
448 		retval = parport_read(port, kbuf, count);
449 
450 		if (retval > 0)
451 			break;
452 
453 		if (nonblock) {
454 			retval = -EAGAIN;
455 			break;
456 		}
457 
458 		/* Wait for data. */
459 
460 		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
461 			parport_negotiate(lp_table[minor].dev->port,
462 					  IEEE1284_MODE_COMPAT);
463 			lp_error(minor);
464 			if (parport_negotiate(lp_table[minor].dev->port,
465 					      IEEE1284_MODE_NIBBLE)) {
466 				retval = -EIO;
467 				goto out;
468 			}
469 		} else {
470 			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
471 			schedule_timeout(LP_TIMEOUT_POLLED);
472 			finish_wait(&lp_table[minor].waitq, &wait);
473 		}
474 
475 		if (signal_pending(current)) {
476 			retval = -ERESTARTSYS;
477 			break;
478 		}
479 
480 		cond_resched();
481 	}
482 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
483  out:
484 	lp_release_parport(&lp_table[minor]);
485 
486 	if (retval > 0 && copy_to_user(buf, kbuf, retval))
487 		retval = -EFAULT;
488 
489 	mutex_unlock(&lp_table[minor].port_mutex);
490 
491 	return retval;
492 }
493 
494 #endif /* IEEE 1284 support */
495 
lp_open(struct inode * inode,struct file * file)496 static int lp_open(struct inode *inode, struct file *file)
497 {
498 	unsigned int minor = iminor(inode);
499 	int ret = 0;
500 
501 	mutex_lock(&lp_mutex);
502 	if (minor >= LP_NO) {
503 		ret = -ENXIO;
504 		goto out;
505 	}
506 	if ((LP_F(minor) & LP_EXIST) == 0) {
507 		ret = -ENXIO;
508 		goto out;
509 	}
510 	if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor))) {
511 		ret = -EBUSY;
512 		goto out;
513 	}
514 	/* If ABORTOPEN is set and the printer is offline or out of paper,
515 	   we may still want to open it to perform ioctl()s.  Therefore we
516 	   have commandeered O_NONBLOCK, even though it is being used in
517 	   a non-standard manner.  This is strictly a Linux hack, and
518 	   should most likely only ever be used by the tunelp application. */
519 	if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
520 		int status;
521 		lp_claim_parport_or_block(&lp_table[minor]);
522 		status = r_str(minor);
523 		lp_release_parport(&lp_table[minor]);
524 		if (status & LP_POUTPA) {
525 			printk(KERN_INFO "lp%d out of paper\n", minor);
526 			LP_F(minor) &= ~LP_BUSY;
527 			ret = -ENOSPC;
528 			goto out;
529 		} else if (!(status & LP_PSELECD)) {
530 			printk(KERN_INFO "lp%d off-line\n", minor);
531 			LP_F(minor) &= ~LP_BUSY;
532 			ret = -EIO;
533 			goto out;
534 		} else if (!(status & LP_PERRORP)) {
535 			printk(KERN_ERR "lp%d printer error\n", minor);
536 			LP_F(minor) &= ~LP_BUSY;
537 			ret = -EIO;
538 			goto out;
539 		}
540 	}
541 	lp_table[minor].lp_buffer = kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
542 	if (!lp_table[minor].lp_buffer) {
543 		LP_F(minor) &= ~LP_BUSY;
544 		ret = -ENOMEM;
545 		goto out;
546 	}
547 	/* Determine if the peripheral supports ECP mode */
548 	lp_claim_parport_or_block(&lp_table[minor]);
549 	if ((lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
550 	     !parport_negotiate(lp_table[minor].dev->port,
551 				 IEEE1284_MODE_ECP)) {
552 		printk(KERN_INFO "lp%d: ECP mode\n", minor);
553 		lp_table[minor].best_mode = IEEE1284_MODE_ECP;
554 	} else {
555 		lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
556 	}
557 	/* Leave peripheral in compatibility mode */
558 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
559 	lp_release_parport(&lp_table[minor]);
560 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
561 out:
562 	mutex_unlock(&lp_mutex);
563 	return ret;
564 }
565 
lp_release(struct inode * inode,struct file * file)566 static int lp_release(struct inode *inode, struct file *file)
567 {
568 	unsigned int minor = iminor(inode);
569 
570 	lp_claim_parport_or_block(&lp_table[minor]);
571 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
572 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
573 	lp_release_parport(&lp_table[minor]);
574 	kfree(lp_table[minor].lp_buffer);
575 	lp_table[minor].lp_buffer = NULL;
576 	LP_F(minor) &= ~LP_BUSY;
577 	return 0;
578 }
579 
lp_do_ioctl(unsigned int minor,unsigned int cmd,unsigned long arg,void __user * argp)580 static int lp_do_ioctl(unsigned int minor, unsigned int cmd,
581 	unsigned long arg, void __user *argp)
582 {
583 	int status;
584 	int retval = 0;
585 
586 #ifdef LP_DEBUG
587 	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
588 #endif
589 	if (minor >= LP_NO)
590 		return -ENODEV;
591 	if ((LP_F(minor) & LP_EXIST) == 0)
592 		return -ENODEV;
593 	switch (cmd) {
594 		case LPTIME:
595 			if (arg > UINT_MAX / HZ)
596 				return -EINVAL;
597 			LP_TIME(minor) = arg * HZ/100;
598 			break;
599 		case LPCHAR:
600 			LP_CHAR(minor) = arg;
601 			break;
602 		case LPABORT:
603 			if (arg)
604 				LP_F(minor) |= LP_ABORT;
605 			else
606 				LP_F(minor) &= ~LP_ABORT;
607 			break;
608 		case LPABORTOPEN:
609 			if (arg)
610 				LP_F(minor) |= LP_ABORTOPEN;
611 			else
612 				LP_F(minor) &= ~LP_ABORTOPEN;
613 			break;
614 		case LPCAREFUL:
615 			if (arg)
616 				LP_F(minor) |= LP_CAREFUL;
617 			else
618 				LP_F(minor) &= ~LP_CAREFUL;
619 			break;
620 		case LPWAIT:
621 			LP_WAIT(minor) = arg;
622 			break;
623 		case LPSETIRQ:
624 			return -EINVAL;
625 		case LPGETIRQ:
626 			if (copy_to_user(argp, &LP_IRQ(minor),
627 					sizeof(int)))
628 				return -EFAULT;
629 			break;
630 		case LPGETSTATUS:
631 			if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
632 				return -EINTR;
633 			lp_claim_parport_or_block(&lp_table[minor]);
634 			status = r_str(minor);
635 			lp_release_parport(&lp_table[minor]);
636 			mutex_unlock(&lp_table[minor].port_mutex);
637 
638 			if (copy_to_user(argp, &status, sizeof(int)))
639 				return -EFAULT;
640 			break;
641 		case LPRESET:
642 			lp_reset(minor);
643 			break;
644 #ifdef LP_STATS
645 		case LPGETSTATS:
646 			if (copy_to_user(argp, &LP_STAT(minor),
647 					sizeof(struct lp_stats)))
648 				return -EFAULT;
649 			if (capable(CAP_SYS_ADMIN))
650 				memset(&LP_STAT(minor), 0,
651 						sizeof(struct lp_stats));
652 			break;
653 #endif
654 		case LPGETFLAGS:
655 			status = LP_F(minor);
656 			if (copy_to_user(argp, &status, sizeof(int)))
657 				return -EFAULT;
658 			break;
659 
660 		default:
661 			retval = -EINVAL;
662 	}
663 	return retval;
664 }
665 
lp_set_timeout(unsigned int minor,s64 tv_sec,long tv_usec)666 static int lp_set_timeout(unsigned int minor, s64 tv_sec, long tv_usec)
667 {
668 	long to_jiffies;
669 
670 	/* Convert to jiffies, place in lp_table */
671 	if (tv_sec < 0 || tv_usec < 0)
672 		return -EINVAL;
673 
674 	/*
675 	 * we used to not check, so let's not make this fatal,
676 	 * but deal with user space passing a 32-bit tv_nsec in
677 	 * a 64-bit field, capping the timeout to 1 second
678 	 * worth of microseconds, and capping the total at
679 	 * MAX_JIFFY_OFFSET.
680 	 */
681 	if (tv_usec > 999999)
682 		tv_usec = 999999;
683 
684 	if (tv_sec >= MAX_SEC_IN_JIFFIES - 1) {
685 		to_jiffies = MAX_JIFFY_OFFSET;
686 	} else {
687 		to_jiffies = DIV_ROUND_UP(tv_usec, 1000000/HZ);
688 		to_jiffies += tv_sec * (long) HZ;
689 	}
690 
691 	if (to_jiffies <= 0) {
692 		return -EINVAL;
693 	}
694 	lp_table[minor].timeout = to_jiffies;
695 	return 0;
696 }
697 
lp_set_timeout32(unsigned int minor,void __user * arg)698 static int lp_set_timeout32(unsigned int minor, void __user *arg)
699 {
700 	s32 karg[2];
701 
702 	if (copy_from_user(karg, arg, sizeof(karg)))
703 		return -EFAULT;
704 
705 	return lp_set_timeout(minor, karg[0], karg[1]);
706 }
707 
lp_set_timeout64(unsigned int minor,void __user * arg)708 static int lp_set_timeout64(unsigned int minor, void __user *arg)
709 {
710 	s64 karg[2];
711 
712 	if (copy_from_user(karg, arg, sizeof(karg)))
713 		return -EFAULT;
714 
715 	/* sparc64 suseconds_t is 32-bit only */
716 	if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
717 		karg[1] >>= 32;
718 
719 	return lp_set_timeout(minor, karg[0], karg[1]);
720 }
721 
lp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)722 static long lp_ioctl(struct file *file, unsigned int cmd,
723 			unsigned long arg)
724 {
725 	unsigned int minor;
726 	int ret;
727 
728 	minor = iminor(file_inode(file));
729 	mutex_lock(&lp_mutex);
730 	switch (cmd) {
731 	case LPSETTIMEOUT_OLD:
732 		if (BITS_PER_LONG == 32) {
733 			ret = lp_set_timeout32(minor, (void __user *)arg);
734 			break;
735 		}
736 		fallthrough;	/* for 64-bit */
737 	case LPSETTIMEOUT_NEW:
738 		ret = lp_set_timeout64(minor, (void __user *)arg);
739 		break;
740 	default:
741 		ret = lp_do_ioctl(minor, cmd, arg, (void __user *)arg);
742 		break;
743 	}
744 	mutex_unlock(&lp_mutex);
745 
746 	return ret;
747 }
748 
749 #ifdef CONFIG_COMPAT
lp_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)750 static long lp_compat_ioctl(struct file *file, unsigned int cmd,
751 			unsigned long arg)
752 {
753 	unsigned int minor;
754 	int ret;
755 
756 	minor = iminor(file_inode(file));
757 	mutex_lock(&lp_mutex);
758 	switch (cmd) {
759 	case LPSETTIMEOUT_OLD:
760 		if (!COMPAT_USE_64BIT_TIME) {
761 			ret = lp_set_timeout32(minor, (void __user *)arg);
762 			break;
763 		}
764 		fallthrough;	/* for x32 mode */
765 	case LPSETTIMEOUT_NEW:
766 		ret = lp_set_timeout64(minor, (void __user *)arg);
767 		break;
768 #ifdef LP_STATS
769 	case LPGETSTATS:
770 		/* FIXME: add an implementation if you set LP_STATS */
771 		ret = -EINVAL;
772 		break;
773 #endif
774 	default:
775 		ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
776 		break;
777 	}
778 	mutex_unlock(&lp_mutex);
779 
780 	return ret;
781 }
782 #endif
783 
784 static const struct file_operations lp_fops = {
785 	.owner		= THIS_MODULE,
786 	.write		= lp_write,
787 	.unlocked_ioctl	= lp_ioctl,
788 #ifdef CONFIG_COMPAT
789 	.compat_ioctl	= lp_compat_ioctl,
790 #endif
791 	.open		= lp_open,
792 	.release	= lp_release,
793 #ifdef CONFIG_PARPORT_1284
794 	.read		= lp_read,
795 #endif
796 	.llseek		= noop_llseek,
797 };
798 
799 /* --- support for console on the line printer ----------------- */
800 
801 #ifdef CONFIG_LP_CONSOLE
802 
803 #define CONSOLE_LP 0
804 
805 /* If the printer is out of paper, we can either lose the messages or
806  * stall until the printer is happy again.  Define CONSOLE_LP_STRICT
807  * non-zero to get the latter behaviour. */
808 #define CONSOLE_LP_STRICT 1
809 
810 /* The console must be locked when we get here. */
811 
lp_console_write(struct console * co,const char * s,unsigned count)812 static void lp_console_write(struct console *co, const char *s,
813 			     unsigned count)
814 {
815 	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
816 	struct parport *port = dev->port;
817 	ssize_t written;
818 
819 	if (parport_claim(dev))
820 		/* Nothing we can do. */
821 		return;
822 
823 	parport_set_timeout(dev, 0);
824 
825 	/* Go to compatibility mode. */
826 	parport_negotiate(port, IEEE1284_MODE_COMPAT);
827 
828 	do {
829 		/* Write the data, converting LF->CRLF as we go. */
830 		ssize_t canwrite = count;
831 		char *lf = memchr(s, '\n', count);
832 		if (lf)
833 			canwrite = lf - s;
834 
835 		if (canwrite > 0) {
836 			written = parport_write(port, s, canwrite);
837 
838 			if (written <= 0)
839 				continue;
840 
841 			s += written;
842 			count -= written;
843 			canwrite -= written;
844 		}
845 
846 		if (lf && canwrite <= 0) {
847 			const char *crlf = "\r\n";
848 			int i = 2;
849 
850 			/* Dodge the original '\n', and put '\r\n' instead. */
851 			s++;
852 			count--;
853 			do {
854 				written = parport_write(port, crlf, i);
855 				if (written > 0) {
856 					i -= written;
857 					crlf += written;
858 				}
859 			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
860 		}
861 	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
862 
863 	parport_release(dev);
864 }
865 
866 static struct console lpcons = {
867 	.name		= "lp",
868 	.write		= lp_console_write,
869 	.flags		= CON_PRINTBUFFER,
870 };
871 
872 #endif /* console on line printer */
873 
874 /* --- initialisation code ------------------------------------- */
875 
876 static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
877 static char *parport[LP_NO];
878 static bool reset;
879 
880 module_param_array(parport, charp, NULL, 0);
881 module_param(reset, bool, 0);
882 
883 #ifndef MODULE
lp_setup(char * str)884 static int __init lp_setup(char *str)
885 {
886 	static int parport_ptr;
887 	int x;
888 
889 	if (get_option(&str, &x)) {
890 		if (x == 0) {
891 			/* disable driver on "lp=" or "lp=0" */
892 			parport_nr[0] = LP_PARPORT_OFF;
893 		} else {
894 			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
895 			return 0;
896 		}
897 	} else if (!strncmp(str, "parport", 7)) {
898 		int n = simple_strtoul(str+7, NULL, 10);
899 		if (parport_ptr < LP_NO)
900 			parport_nr[parport_ptr++] = n;
901 		else
902 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
903 			       str);
904 	} else if (!strcmp(str, "auto")) {
905 		parport_nr[0] = LP_PARPORT_AUTO;
906 	} else if (!strcmp(str, "none")) {
907 		if (parport_ptr < LP_NO)
908 			parport_nr[parport_ptr++] = LP_PARPORT_NONE;
909 		else
910 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
911 			       str);
912 	} else if (!strcmp(str, "reset")) {
913 		reset = true;
914 	}
915 	return 1;
916 }
917 #endif
918 
lp_register(int nr,struct parport * port)919 static int lp_register(int nr, struct parport *port)
920 {
921 	struct pardev_cb ppdev_cb;
922 
923 	memset(&ppdev_cb, 0, sizeof(ppdev_cb));
924 	ppdev_cb.preempt = lp_preempt;
925 	ppdev_cb.private = &lp_table[nr];
926 	lp_table[nr].dev = parport_register_dev_model(port, "lp",
927 						      &ppdev_cb, nr);
928 	if (lp_table[nr].dev == NULL)
929 		return 1;
930 	lp_table[nr].flags |= LP_EXIST;
931 
932 	if (reset)
933 		lp_reset(nr);
934 
935 	device_create(lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
936 		      "lp%d", nr);
937 
938 	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
939 	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
940 
941 #ifdef CONFIG_LP_CONSOLE
942 	if (!nr) {
943 		if (port->modes & PARPORT_MODE_SAFEININT) {
944 			register_console(&lpcons);
945 			console_registered = port;
946 			printk(KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
947 		} else
948 			printk(KERN_ERR "lp%d: cannot run console on %s\n",
949 			       CONSOLE_LP, port->name);
950 	}
951 #endif
952 	port_num[nr] = port->number;
953 
954 	return 0;
955 }
956 
lp_attach(struct parport * port)957 static void lp_attach(struct parport *port)
958 {
959 	unsigned int i;
960 
961 	switch (parport_nr[0]) {
962 	case LP_PARPORT_UNSPEC:
963 	case LP_PARPORT_AUTO:
964 		if (parport_nr[0] == LP_PARPORT_AUTO &&
965 		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
966 			return;
967 		if (lp_count == LP_NO) {
968 			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
969 			return;
970 		}
971 		for (i = 0; i < LP_NO; i++)
972 			if (port_num[i] == -1)
973 				break;
974 
975 		if (!lp_register(i, port))
976 			lp_count++;
977 		break;
978 
979 	default:
980 		for (i = 0; i < LP_NO; i++) {
981 			if (port->number == parport_nr[i]) {
982 				if (!lp_register(i, port))
983 					lp_count++;
984 				break;
985 			}
986 		}
987 		break;
988 	}
989 }
990 
lp_detach(struct parport * port)991 static void lp_detach(struct parport *port)
992 {
993 	int n;
994 
995 	/* Write this some day. */
996 #ifdef CONFIG_LP_CONSOLE
997 	if (console_registered == port) {
998 		unregister_console(&lpcons);
999 		console_registered = NULL;
1000 	}
1001 #endif /* CONFIG_LP_CONSOLE */
1002 
1003 	for (n = 0; n < LP_NO; n++) {
1004 		if (port_num[n] == port->number) {
1005 			port_num[n] = -1;
1006 			lp_count--;
1007 			device_destroy(lp_class, MKDEV(LP_MAJOR, n));
1008 			parport_unregister_device(lp_table[n].dev);
1009 		}
1010 	}
1011 }
1012 
1013 static struct parport_driver lp_driver = {
1014 	.name = "lp",
1015 	.match_port = lp_attach,
1016 	.detach = lp_detach,
1017 	.devmodel = true,
1018 };
1019 
lp_init(void)1020 static int __init lp_init(void)
1021 {
1022 	int i, err;
1023 
1024 	if (parport_nr[0] == LP_PARPORT_OFF)
1025 		return 0;
1026 
1027 	for (i = 0; i < LP_NO; i++) {
1028 		lp_table[i].dev = NULL;
1029 		lp_table[i].flags = 0;
1030 		lp_table[i].chars = LP_INIT_CHAR;
1031 		lp_table[i].time = LP_INIT_TIME;
1032 		lp_table[i].wait = LP_INIT_WAIT;
1033 		lp_table[i].lp_buffer = NULL;
1034 #ifdef LP_STATS
1035 		lp_table[i].lastcall = 0;
1036 		lp_table[i].runchars = 0;
1037 		memset(&lp_table[i].stats, 0, sizeof(struct lp_stats));
1038 #endif
1039 		lp_table[i].last_error = 0;
1040 		init_waitqueue_head(&lp_table[i].waitq);
1041 		init_waitqueue_head(&lp_table[i].dataq);
1042 		mutex_init(&lp_table[i].port_mutex);
1043 		lp_table[i].timeout = 10 * HZ;
1044 		port_num[i] = -1;
1045 	}
1046 
1047 	if (register_chrdev(LP_MAJOR, "lp", &lp_fops)) {
1048 		printk(KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
1049 		return -EIO;
1050 	}
1051 
1052 	lp_class = class_create(THIS_MODULE, "printer");
1053 	if (IS_ERR(lp_class)) {
1054 		err = PTR_ERR(lp_class);
1055 		goto out_reg;
1056 	}
1057 
1058 	if (parport_register_driver(&lp_driver)) {
1059 		printk(KERN_ERR "lp: unable to register with parport\n");
1060 		err = -EIO;
1061 		goto out_class;
1062 	}
1063 
1064 	if (!lp_count) {
1065 		printk(KERN_INFO "lp: driver loaded but no devices found\n");
1066 #ifndef CONFIG_PARPORT_1284
1067 		if (parport_nr[0] == LP_PARPORT_AUTO)
1068 			printk(KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
1069 #endif
1070 	}
1071 
1072 	return 0;
1073 
1074 out_class:
1075 	class_destroy(lp_class);
1076 out_reg:
1077 	unregister_chrdev(LP_MAJOR, "lp");
1078 	return err;
1079 }
1080 
lp_init_module(void)1081 static int __init lp_init_module(void)
1082 {
1083 	if (parport[0]) {
1084 		/* The user gave some parameters.  Let's see what they were.  */
1085 		if (!strncmp(parport[0], "auto", 4))
1086 			parport_nr[0] = LP_PARPORT_AUTO;
1087 		else {
1088 			int n;
1089 			for (n = 0; n < LP_NO && parport[n]; n++) {
1090 				if (!strncmp(parport[n], "none", 4))
1091 					parport_nr[n] = LP_PARPORT_NONE;
1092 				else {
1093 					char *ep;
1094 					unsigned long r = simple_strtoul(parport[n], &ep, 0);
1095 					if (ep != parport[n])
1096 						parport_nr[n] = r;
1097 					else {
1098 						printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
1099 						return -ENODEV;
1100 					}
1101 				}
1102 			}
1103 		}
1104 	}
1105 
1106 	return lp_init();
1107 }
1108 
lp_cleanup_module(void)1109 static void lp_cleanup_module(void)
1110 {
1111 	parport_unregister_driver(&lp_driver);
1112 
1113 #ifdef CONFIG_LP_CONSOLE
1114 	unregister_console(&lpcons);
1115 #endif
1116 
1117 	unregister_chrdev(LP_MAJOR, "lp");
1118 	class_destroy(lp_class);
1119 }
1120 
1121 __setup("lp=", lp_setup);
1122 module_init(lp_init_module);
1123 module_exit(lp_cleanup_module);
1124 
1125 MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
1126 MODULE_LICENSE("GPL");
1127