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 const struct class lp_class = {
149 	.name = "printer",
150 };
151 
152 #ifdef CONFIG_LP_CONSOLE
153 static struct parport *console_registered;
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 */
lp_claim_parport_or_block(struct lp_struct * this_lp)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 */
lp_release_parport(struct lp_struct * this_lp)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 
lp_preempt(void * handle)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  */
lp_negotiate(struct parport * port,int mode)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 
lp_reset(int minor)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 
lp_error(int minor)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)
231 		lp_release_parport(&lp_table[minor]);
232 	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
233 	schedule_timeout(LP_TIMEOUT_POLLED);
234 	finish_wait(&lp_table[minor].waitq, &wait);
235 	if (polling)
236 		lp_claim_parport_or_block(&lp_table[minor]);
237 	else
238 		parport_yield_blocking(lp_table[minor].dev);
239 }
240 
lp_check_status(int minor)241 static int lp_check_status(int minor)
242 {
243 	int error = 0;
244 	unsigned int last = lp_table[minor].last_error;
245 	unsigned char status = r_str(minor);
246 	if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
247 		/* No error. */
248 		last = 0;
249 	else if ((status & LP_POUTPA)) {
250 		if (last != LP_POUTPA) {
251 			last = LP_POUTPA;
252 			printk(KERN_INFO "lp%d out of paper\n", minor);
253 		}
254 		error = -ENOSPC;
255 	} else if (!(status & LP_PSELECD)) {
256 		if (last != LP_PSELECD) {
257 			last = LP_PSELECD;
258 			printk(KERN_INFO "lp%d off-line\n", minor);
259 		}
260 		error = -EIO;
261 	} else if (!(status & LP_PERRORP)) {
262 		if (last != LP_PERRORP) {
263 			last = LP_PERRORP;
264 			printk(KERN_INFO "lp%d on fire\n", minor);
265 		}
266 		error = -EIO;
267 	} else {
268 		last = 0; /* Come here if LP_CAREFUL is set and no
269 			     errors are reported. */
270 	}
271 
272 	lp_table[minor].last_error = last;
273 
274 	if (last != 0)
275 		lp_error(minor);
276 
277 	return error;
278 }
279 
lp_wait_ready(int minor,int nonblock)280 static int lp_wait_ready(int minor, int nonblock)
281 {
282 	int error = 0;
283 
284 	/* If we're not in compatibility mode, we're ready now! */
285 	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
286 		return 0;
287 	}
288 
289 	do {
290 		error = lp_check_status(minor);
291 		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
292 			break;
293 		if (signal_pending(current)) {
294 			error = -EINTR;
295 			break;
296 		}
297 	} while (error);
298 	return error;
299 }
300 
lp_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)301 static ssize_t lp_write(struct file *file, const char __user *buf,
302 			size_t count, loff_t *ppos)
303 {
304 	unsigned int minor = iminor(file_inode(file));
305 	struct parport *port = lp_table[minor].dev->port;
306 	char *kbuf = lp_table[minor].lp_buffer;
307 	ssize_t retv = 0;
308 	ssize_t written;
309 	size_t copy_size = count;
310 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
311 			(LP_F(minor) & LP_ABORT));
312 
313 #ifdef LP_STATS
314 	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
315 		lp_table[minor].runchars = 0;
316 
317 	lp_table[minor].lastcall = jiffies;
318 #endif
319 
320 	/* Need to copy the data from user-space. */
321 	if (copy_size > LP_BUFFER_SIZE)
322 		copy_size = LP_BUFFER_SIZE;
323 
324 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
325 		return -EINTR;
326 
327 	if (copy_from_user(kbuf, buf, copy_size)) {
328 		retv = -EFAULT;
329 		goto out_unlock;
330 	}
331 
332 	/* Claim Parport or sleep until it becomes available
333 	 */
334 	lp_claim_parport_or_block(&lp_table[minor]);
335 	/* Go to the proper mode. */
336 	lp_table[minor].current_mode = lp_negotiate(port,
337 						    lp_table[minor].best_mode);
338 
339 	parport_set_timeout(lp_table[minor].dev,
340 			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
341 			     : lp_table[minor].timeout));
342 
343 	if ((retv = lp_wait_ready(minor, nonblock)) == 0)
344 	do {
345 		/* Write the data. */
346 		written = parport_write(port, kbuf, copy_size);
347 		if (written > 0) {
348 			copy_size -= written;
349 			count -= written;
350 			buf  += written;
351 			retv += written;
352 		}
353 
354 		if (signal_pending(current)) {
355 			if (retv == 0)
356 				retv = -EINTR;
357 
358 			break;
359 		}
360 
361 		if (copy_size > 0) {
362 			/* incomplete write -> check error ! */
363 			int error;
364 
365 			parport_negotiate(lp_table[minor].dev->port,
366 					  IEEE1284_MODE_COMPAT);
367 			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
368 
369 			error = lp_wait_ready(minor, nonblock);
370 
371 			if (error) {
372 				if (retv == 0)
373 					retv = error;
374 				break;
375 			} else if (nonblock) {
376 				if (retv == 0)
377 					retv = -EAGAIN;
378 				break;
379 			}
380 
381 			parport_yield_blocking(lp_table[minor].dev);
382 			lp_table[minor].current_mode
383 			  = lp_negotiate(port,
384 					 lp_table[minor].best_mode);
385 
386 		} else if (need_resched())
387 			schedule();
388 
389 		if (count) {
390 			copy_size = count;
391 			if (copy_size > LP_BUFFER_SIZE)
392 				copy_size = LP_BUFFER_SIZE;
393 
394 			if (copy_from_user(kbuf, buf, copy_size)) {
395 				if (retv == 0)
396 					retv = -EFAULT;
397 				break;
398 			}
399 		}
400 	} while (count > 0);
401 
402 	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
403 			       &lp_table[minor].bits)) {
404 		printk(KERN_INFO "lp%d releasing parport\n", minor);
405 		parport_negotiate(lp_table[minor].dev->port,
406 				  IEEE1284_MODE_COMPAT);
407 		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
408 		lp_release_parport(&lp_table[minor]);
409 	}
410 out_unlock:
411 	mutex_unlock(&lp_table[minor].port_mutex);
412 
413 	return retv;
414 }
415 
416 #ifdef CONFIG_PARPORT_1284
417 
418 /* Status readback conforming to ieee1284 */
lp_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)419 static ssize_t lp_read(struct file *file, char __user *buf,
420 		       size_t count, loff_t *ppos)
421 {
422 	DEFINE_WAIT(wait);
423 	unsigned int minor=iminor(file_inode(file));
424 	struct parport *port = lp_table[minor].dev->port;
425 	ssize_t retval = 0;
426 	char *kbuf = lp_table[minor].lp_buffer;
427 	int nonblock = ((file->f_flags & O_NONBLOCK) ||
428 			(LP_F(minor) & LP_ABORT));
429 
430 	if (count > LP_BUFFER_SIZE)
431 		count = LP_BUFFER_SIZE;
432 
433 	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
434 		return -EINTR;
435 
436 	lp_claim_parport_or_block(&lp_table[minor]);
437 
438 	parport_set_timeout(lp_table[minor].dev,
439 			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
440 			     : lp_table[minor].timeout));
441 
442 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
443 	if (parport_negotiate(lp_table[minor].dev->port,
444 			      IEEE1284_MODE_NIBBLE)) {
445 		retval = -EIO;
446 		goto out;
447 	}
448 
449 	while (retval == 0) {
450 		retval = parport_read(port, kbuf, count);
451 
452 		if (retval > 0)
453 			break;
454 
455 		if (nonblock) {
456 			retval = -EAGAIN;
457 			break;
458 		}
459 
460 		/* Wait for data. */
461 
462 		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
463 			parport_negotiate(lp_table[minor].dev->port,
464 					  IEEE1284_MODE_COMPAT);
465 			lp_error(minor);
466 			if (parport_negotiate(lp_table[minor].dev->port,
467 					      IEEE1284_MODE_NIBBLE)) {
468 				retval = -EIO;
469 				goto out;
470 			}
471 		} else {
472 			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
473 			schedule_timeout(LP_TIMEOUT_POLLED);
474 			finish_wait(&lp_table[minor].waitq, &wait);
475 		}
476 
477 		if (signal_pending(current)) {
478 			retval = -ERESTARTSYS;
479 			break;
480 		}
481 
482 		cond_resched();
483 	}
484 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
485  out:
486 	lp_release_parport(&lp_table[minor]);
487 
488 	if (retval > 0 && copy_to_user(buf, kbuf, retval))
489 		retval = -EFAULT;
490 
491 	mutex_unlock(&lp_table[minor].port_mutex);
492 
493 	return retval;
494 }
495 
496 #endif /* IEEE 1284 support */
497 
lp_open(struct inode * inode,struct file * file)498 static int lp_open(struct inode *inode, struct file *file)
499 {
500 	unsigned int minor = iminor(inode);
501 	int ret = 0;
502 
503 	mutex_lock(&lp_mutex);
504 	if (minor >= LP_NO) {
505 		ret = -ENXIO;
506 		goto out;
507 	}
508 	if ((LP_F(minor) & LP_EXIST) == 0) {
509 		ret = -ENXIO;
510 		goto out;
511 	}
512 	if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor))) {
513 		ret = -EBUSY;
514 		goto out;
515 	}
516 	/* If ABORTOPEN is set and the printer is offline or out of paper,
517 	   we may still want to open it to perform ioctl()s.  Therefore we
518 	   have commandeered O_NONBLOCK, even though it is being used in
519 	   a non-standard manner.  This is strictly a Linux hack, and
520 	   should most likely only ever be used by the tunelp application. */
521 	if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
522 		int status;
523 		lp_claim_parport_or_block(&lp_table[minor]);
524 		status = r_str(minor);
525 		lp_release_parport(&lp_table[minor]);
526 		if (status & LP_POUTPA) {
527 			printk(KERN_INFO "lp%d out of paper\n", minor);
528 			LP_F(minor) &= ~LP_BUSY;
529 			ret = -ENOSPC;
530 			goto out;
531 		} else if (!(status & LP_PSELECD)) {
532 			printk(KERN_INFO "lp%d off-line\n", minor);
533 			LP_F(minor) &= ~LP_BUSY;
534 			ret = -EIO;
535 			goto out;
536 		} else if (!(status & LP_PERRORP)) {
537 			printk(KERN_ERR "lp%d printer error\n", minor);
538 			LP_F(minor) &= ~LP_BUSY;
539 			ret = -EIO;
540 			goto out;
541 		}
542 	}
543 	lp_table[minor].lp_buffer = kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
544 	if (!lp_table[minor].lp_buffer) {
545 		LP_F(minor) &= ~LP_BUSY;
546 		ret = -ENOMEM;
547 		goto out;
548 	}
549 	/* Determine if the peripheral supports ECP mode */
550 	lp_claim_parport_or_block(&lp_table[minor]);
551 	if ((lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
552 	     !parport_negotiate(lp_table[minor].dev->port,
553 				 IEEE1284_MODE_ECP)) {
554 		printk(KERN_INFO "lp%d: ECP mode\n", minor);
555 		lp_table[minor].best_mode = IEEE1284_MODE_ECP;
556 	} else {
557 		lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
558 	}
559 	/* Leave peripheral in compatibility mode */
560 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
561 	lp_release_parport(&lp_table[minor]);
562 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
563 out:
564 	mutex_unlock(&lp_mutex);
565 	return ret;
566 }
567 
lp_release(struct inode * inode,struct file * file)568 static int lp_release(struct inode *inode, struct file *file)
569 {
570 	unsigned int minor = iminor(inode);
571 
572 	lp_claim_parport_or_block(&lp_table[minor]);
573 	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
574 	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
575 	lp_release_parport(&lp_table[minor]);
576 	kfree(lp_table[minor].lp_buffer);
577 	lp_table[minor].lp_buffer = NULL;
578 	LP_F(minor) &= ~LP_BUSY;
579 	return 0;
580 }
581 
lp_do_ioctl(unsigned int minor,unsigned int cmd,unsigned long arg,void __user * argp)582 static int lp_do_ioctl(unsigned int minor, unsigned int cmd,
583 	unsigned long arg, void __user *argp)
584 {
585 	int status;
586 	int retval = 0;
587 
588 #ifdef LP_DEBUG
589 	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
590 #endif
591 	if (minor >= LP_NO)
592 		return -ENODEV;
593 	if ((LP_F(minor) & LP_EXIST) == 0)
594 		return -ENODEV;
595 	switch (cmd) {
596 		case LPTIME:
597 			if (arg > UINT_MAX / HZ)
598 				return -EINVAL;
599 			LP_TIME(minor) = arg * HZ/100;
600 			break;
601 		case LPCHAR:
602 			LP_CHAR(minor) = arg;
603 			break;
604 		case LPABORT:
605 			if (arg)
606 				LP_F(minor) |= LP_ABORT;
607 			else
608 				LP_F(minor) &= ~LP_ABORT;
609 			break;
610 		case LPABORTOPEN:
611 			if (arg)
612 				LP_F(minor) |= LP_ABORTOPEN;
613 			else
614 				LP_F(minor) &= ~LP_ABORTOPEN;
615 			break;
616 		case LPCAREFUL:
617 			if (arg)
618 				LP_F(minor) |= LP_CAREFUL;
619 			else
620 				LP_F(minor) &= ~LP_CAREFUL;
621 			break;
622 		case LPWAIT:
623 			LP_WAIT(minor) = arg;
624 			break;
625 		case LPSETIRQ:
626 			return -EINVAL;
627 		case LPGETIRQ:
628 			if (copy_to_user(argp, &LP_IRQ(minor),
629 					sizeof(int)))
630 				return -EFAULT;
631 			break;
632 		case LPGETSTATUS:
633 			if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
634 				return -EINTR;
635 			lp_claim_parport_or_block(&lp_table[minor]);
636 			status = r_str(minor);
637 			lp_release_parport(&lp_table[minor]);
638 			mutex_unlock(&lp_table[minor].port_mutex);
639 
640 			if (copy_to_user(argp, &status, sizeof(int)))
641 				return -EFAULT;
642 			break;
643 		case LPRESET:
644 			lp_reset(minor);
645 			break;
646 #ifdef LP_STATS
647 		case LPGETSTATS:
648 			if (copy_to_user(argp, &LP_STAT(minor),
649 					sizeof(struct lp_stats)))
650 				return -EFAULT;
651 			if (capable(CAP_SYS_ADMIN))
652 				memset(&LP_STAT(minor), 0,
653 						sizeof(struct lp_stats));
654 			break;
655 #endif
656 		case LPGETFLAGS:
657 			status = LP_F(minor);
658 			if (copy_to_user(argp, &status, sizeof(int)))
659 				return -EFAULT;
660 			break;
661 
662 		default:
663 			retval = -EINVAL;
664 	}
665 	return retval;
666 }
667 
lp_set_timeout(unsigned int minor,s64 tv_sec,long tv_usec)668 static int lp_set_timeout(unsigned int minor, s64 tv_sec, long tv_usec)
669 {
670 	long to_jiffies;
671 
672 	/* Convert to jiffies, place in lp_table */
673 	if (tv_sec < 0 || tv_usec < 0)
674 		return -EINVAL;
675 
676 	/*
677 	 * we used to not check, so let's not make this fatal,
678 	 * but deal with user space passing a 32-bit tv_nsec in
679 	 * a 64-bit field, capping the timeout to 1 second
680 	 * worth of microseconds, and capping the total at
681 	 * MAX_JIFFY_OFFSET.
682 	 */
683 	if (tv_usec > 999999)
684 		tv_usec = 999999;
685 
686 	if (tv_sec >= MAX_SEC_IN_JIFFIES - 1) {
687 		to_jiffies = MAX_JIFFY_OFFSET;
688 	} else {
689 		to_jiffies = DIV_ROUND_UP(tv_usec, 1000000/HZ);
690 		to_jiffies += tv_sec * (long) HZ;
691 	}
692 
693 	if (to_jiffies <= 0) {
694 		return -EINVAL;
695 	}
696 	lp_table[minor].timeout = to_jiffies;
697 	return 0;
698 }
699 
lp_set_timeout32(unsigned int minor,void __user * arg)700 static int lp_set_timeout32(unsigned int minor, void __user *arg)
701 {
702 	s32 karg[2];
703 
704 	if (copy_from_user(karg, arg, sizeof(karg)))
705 		return -EFAULT;
706 
707 	return lp_set_timeout(minor, karg[0], karg[1]);
708 }
709 
lp_set_timeout64(unsigned int minor,void __user * arg)710 static int lp_set_timeout64(unsigned int minor, void __user *arg)
711 {
712 	s64 karg[2];
713 
714 	if (copy_from_user(karg, arg, sizeof(karg)))
715 		return -EFAULT;
716 
717 	/* sparc64 suseconds_t is 32-bit only */
718 	if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
719 		karg[1] >>= 32;
720 
721 	return lp_set_timeout(minor, karg[0], karg[1]);
722 }
723 
lp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)724 static long lp_ioctl(struct file *file, unsigned int cmd,
725 			unsigned long arg)
726 {
727 	unsigned int minor;
728 	int ret;
729 
730 	minor = iminor(file_inode(file));
731 	mutex_lock(&lp_mutex);
732 	switch (cmd) {
733 	case LPSETTIMEOUT_OLD:
734 		if (BITS_PER_LONG == 32) {
735 			ret = lp_set_timeout32(minor, (void __user *)arg);
736 			break;
737 		}
738 		fallthrough;	/* for 64-bit */
739 	case LPSETTIMEOUT_NEW:
740 		ret = lp_set_timeout64(minor, (void __user *)arg);
741 		break;
742 	default:
743 		ret = lp_do_ioctl(minor, cmd, arg, (void __user *)arg);
744 		break;
745 	}
746 	mutex_unlock(&lp_mutex);
747 
748 	return ret;
749 }
750 
751 #ifdef CONFIG_COMPAT
lp_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)752 static long lp_compat_ioctl(struct file *file, unsigned int cmd,
753 			unsigned long arg)
754 {
755 	unsigned int minor;
756 	int ret;
757 
758 	minor = iminor(file_inode(file));
759 	mutex_lock(&lp_mutex);
760 	switch (cmd) {
761 	case LPSETTIMEOUT_OLD:
762 		if (!COMPAT_USE_64BIT_TIME) {
763 			ret = lp_set_timeout32(minor, (void __user *)arg);
764 			break;
765 		}
766 		fallthrough;	/* for x32 mode */
767 	case LPSETTIMEOUT_NEW:
768 		ret = lp_set_timeout64(minor, (void __user *)arg);
769 		break;
770 #ifdef LP_STATS
771 	case LPGETSTATS:
772 		/* FIXME: add an implementation if you set LP_STATS */
773 		ret = -EINVAL;
774 		break;
775 #endif
776 	default:
777 		ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
778 		break;
779 	}
780 	mutex_unlock(&lp_mutex);
781 
782 	return ret;
783 }
784 #endif
785 
786 static const struct file_operations lp_fops = {
787 	.owner		= THIS_MODULE,
788 	.write		= lp_write,
789 	.unlocked_ioctl	= lp_ioctl,
790 #ifdef CONFIG_COMPAT
791 	.compat_ioctl	= lp_compat_ioctl,
792 #endif
793 	.open		= lp_open,
794 	.release	= lp_release,
795 #ifdef CONFIG_PARPORT_1284
796 	.read		= lp_read,
797 #endif
798 	.llseek		= noop_llseek,
799 };
800 
801 /* --- support for console on the line printer ----------------- */
802 
803 #ifdef CONFIG_LP_CONSOLE
804 
805 #define CONSOLE_LP 0
806 
807 /* If the printer is out of paper, we can either lose the messages or
808  * stall until the printer is happy again.  Define CONSOLE_LP_STRICT
809  * non-zero to get the latter behaviour. */
810 #define CONSOLE_LP_STRICT 1
811 
812 /* The console must be locked when we get here. */
813 
lp_console_write(struct console * co,const char * s,unsigned count)814 static void lp_console_write(struct console *co, const char *s,
815 			     unsigned count)
816 {
817 	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
818 	struct parport *port = dev->port;
819 	ssize_t written;
820 
821 	if (parport_claim(dev))
822 		/* Nothing we can do. */
823 		return;
824 
825 	parport_set_timeout(dev, 0);
826 
827 	/* Go to compatibility mode. */
828 	parport_negotiate(port, IEEE1284_MODE_COMPAT);
829 
830 	do {
831 		/* Write the data, converting LF->CRLF as we go. */
832 		ssize_t canwrite = count;
833 		char *lf = memchr(s, '\n', count);
834 		if (lf)
835 			canwrite = lf - s;
836 
837 		if (canwrite > 0) {
838 			written = parport_write(port, s, canwrite);
839 
840 			if (written <= 0)
841 				continue;
842 
843 			s += written;
844 			count -= written;
845 			canwrite -= written;
846 		}
847 
848 		if (lf && canwrite <= 0) {
849 			const char *crlf = "\r\n";
850 			int i = 2;
851 
852 			/* Dodge the original '\n', and put '\r\n' instead. */
853 			s++;
854 			count--;
855 			do {
856 				written = parport_write(port, crlf, i);
857 				if (written > 0) {
858 					i -= written;
859 					crlf += written;
860 				}
861 			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
862 		}
863 	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
864 
865 	parport_release(dev);
866 }
867 
868 static struct console lpcons = {
869 	.name		= "lp",
870 	.write		= lp_console_write,
871 	.flags		= CON_PRINTBUFFER,
872 };
873 
874 #endif /* console on line printer */
875 
876 /* --- initialisation code ------------------------------------- */
877 
878 static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
879 static char *parport[LP_NO];
880 static bool reset;
881 
882 module_param_array(parport, charp, NULL, 0);
883 module_param(reset, bool, 0);
884 
885 #ifndef MODULE
lp_setup(char * str)886 static int __init lp_setup(char *str)
887 {
888 	static int parport_ptr;
889 	int x;
890 
891 	if (get_option(&str, &x)) {
892 		if (x == 0) {
893 			/* disable driver on "lp=" or "lp=0" */
894 			parport_nr[0] = LP_PARPORT_OFF;
895 		} else {
896 			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
897 			return 0;
898 		}
899 	} else if (!strncmp(str, "parport", 7)) {
900 		int n = simple_strtoul(str+7, NULL, 10);
901 		if (parport_ptr < LP_NO)
902 			parport_nr[parport_ptr++] = n;
903 		else
904 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
905 			       str);
906 	} else if (!strcmp(str, "auto")) {
907 		parport_nr[0] = LP_PARPORT_AUTO;
908 	} else if (!strcmp(str, "none")) {
909 		if (parport_ptr < LP_NO)
910 			parport_nr[parport_ptr++] = LP_PARPORT_NONE;
911 		else
912 			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
913 			       str);
914 	} else if (!strcmp(str, "reset")) {
915 		reset = true;
916 	}
917 	return 1;
918 }
919 #endif
920 
lp_register(int nr,struct parport * port)921 static int lp_register(int nr, struct parport *port)
922 {
923 	struct pardev_cb ppdev_cb;
924 
925 	memset(&ppdev_cb, 0, sizeof(ppdev_cb));
926 	ppdev_cb.preempt = lp_preempt;
927 	ppdev_cb.private = &lp_table[nr];
928 	lp_table[nr].dev = parport_register_dev_model(port, "lp",
929 						      &ppdev_cb, nr);
930 	if (lp_table[nr].dev == NULL)
931 		return 1;
932 	lp_table[nr].flags |= LP_EXIST;
933 
934 	if (reset)
935 		lp_reset(nr);
936 
937 	device_create(&lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
938 		      "lp%d", nr);
939 
940 	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
941 	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
942 
943 #ifdef CONFIG_LP_CONSOLE
944 	if (!nr) {
945 		if (port->modes & PARPORT_MODE_SAFEININT) {
946 			register_console(&lpcons);
947 			console_registered = port;
948 			printk(KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
949 		} else
950 			printk(KERN_ERR "lp%d: cannot run console on %s\n",
951 			       CONSOLE_LP, port->name);
952 	}
953 #endif
954 	port_num[nr] = port->number;
955 
956 	return 0;
957 }
958 
lp_attach(struct parport * port)959 static void lp_attach(struct parport *port)
960 {
961 	unsigned int i;
962 
963 	switch (parport_nr[0]) {
964 	case LP_PARPORT_UNSPEC:
965 	case LP_PARPORT_AUTO:
966 		if (parport_nr[0] == LP_PARPORT_AUTO &&
967 		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
968 			return;
969 		if (lp_count == LP_NO) {
970 			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
971 			return;
972 		}
973 		for (i = 0; i < LP_NO; i++)
974 			if (port_num[i] == -1)
975 				break;
976 
977 		if (!lp_register(i, port))
978 			lp_count++;
979 		break;
980 
981 	default:
982 		for (i = 0; i < LP_NO; i++) {
983 			if (port->number == parport_nr[i]) {
984 				if (!lp_register(i, port))
985 					lp_count++;
986 				break;
987 			}
988 		}
989 		break;
990 	}
991 }
992 
lp_detach(struct parport * port)993 static void lp_detach(struct parport *port)
994 {
995 	int n;
996 
997 	/* Write this some day. */
998 #ifdef CONFIG_LP_CONSOLE
999 	if (console_registered == port) {
1000 		unregister_console(&lpcons);
1001 		console_registered = NULL;
1002 	}
1003 #endif /* CONFIG_LP_CONSOLE */
1004 
1005 	for (n = 0; n < LP_NO; n++) {
1006 		if (port_num[n] == port->number) {
1007 			port_num[n] = -1;
1008 			lp_count--;
1009 			device_destroy(&lp_class, MKDEV(LP_MAJOR, n));
1010 			parport_unregister_device(lp_table[n].dev);
1011 		}
1012 	}
1013 }
1014 
1015 static struct parport_driver lp_driver = {
1016 	.name = "lp",
1017 	.match_port = lp_attach,
1018 	.detach = lp_detach,
1019 };
1020 
lp_init(void)1021 static int __init lp_init(void)
1022 {
1023 	int i, err;
1024 
1025 	if (parport_nr[0] == LP_PARPORT_OFF)
1026 		return 0;
1027 
1028 	for (i = 0; i < LP_NO; i++) {
1029 		lp_table[i].dev = NULL;
1030 		lp_table[i].flags = 0;
1031 		lp_table[i].chars = LP_INIT_CHAR;
1032 		lp_table[i].time = LP_INIT_TIME;
1033 		lp_table[i].wait = LP_INIT_WAIT;
1034 		lp_table[i].lp_buffer = NULL;
1035 #ifdef LP_STATS
1036 		lp_table[i].lastcall = 0;
1037 		lp_table[i].runchars = 0;
1038 		memset(&lp_table[i].stats, 0, sizeof(struct lp_stats));
1039 #endif
1040 		lp_table[i].last_error = 0;
1041 		init_waitqueue_head(&lp_table[i].waitq);
1042 		init_waitqueue_head(&lp_table[i].dataq);
1043 		mutex_init(&lp_table[i].port_mutex);
1044 		lp_table[i].timeout = 10 * HZ;
1045 		port_num[i] = -1;
1046 	}
1047 
1048 	if (register_chrdev(LP_MAJOR, "lp", &lp_fops)) {
1049 		printk(KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
1050 		return -EIO;
1051 	}
1052 
1053 	err = class_register(&lp_class);
1054 	if (err)
1055 		goto out_reg;
1056 
1057 	if (parport_register_driver(&lp_driver)) {
1058 		printk(KERN_ERR "lp: unable to register with parport\n");
1059 		err = -EIO;
1060 		goto out_class;
1061 	}
1062 
1063 	if (!lp_count) {
1064 		printk(KERN_INFO "lp: driver loaded but no devices found\n");
1065 #ifndef CONFIG_PARPORT_1284
1066 		if (parport_nr[0] == LP_PARPORT_AUTO)
1067 			printk(KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
1068 #endif
1069 	}
1070 
1071 	return 0;
1072 
1073 out_class:
1074 	class_unregister(&lp_class);
1075 out_reg:
1076 	unregister_chrdev(LP_MAJOR, "lp");
1077 	return err;
1078 }
1079 
lp_init_module(void)1080 static int __init lp_init_module(void)
1081 {
1082 	if (parport[0]) {
1083 		/* The user gave some parameters.  Let's see what they were.  */
1084 		if (!strncmp(parport[0], "auto", 4))
1085 			parport_nr[0] = LP_PARPORT_AUTO;
1086 		else {
1087 			int n;
1088 			for (n = 0; n < LP_NO && parport[n]; n++) {
1089 				if (!strncmp(parport[n], "none", 4))
1090 					parport_nr[n] = LP_PARPORT_NONE;
1091 				else {
1092 					char *ep;
1093 					unsigned long r = simple_strtoul(parport[n], &ep, 0);
1094 					if (ep != parport[n])
1095 						parport_nr[n] = r;
1096 					else {
1097 						printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
1098 						return -ENODEV;
1099 					}
1100 				}
1101 			}
1102 		}
1103 	}
1104 
1105 	return lp_init();
1106 }
1107 
lp_cleanup_module(void)1108 static void lp_cleanup_module(void)
1109 {
1110 	parport_unregister_driver(&lp_driver);
1111 
1112 #ifdef CONFIG_LP_CONSOLE
1113 	unregister_console(&lpcons);
1114 #endif
1115 
1116 	unregister_chrdev(LP_MAJOR, "lp");
1117 	class_unregister(&lp_class);
1118 }
1119 
1120 __setup("lp=", lp_setup);
1121 module_init(lp_init_module);
1122 module_exit(lp_cleanup_module);
1123 
1124 MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
1125 MODULE_DESCRIPTION("Generic parallel printer driver");
1126 MODULE_LICENSE("GPL");
1127