xref: /openbmc/linux/drivers/tty/ipwireless/tty.c (revision eb3fcf00)
1 /*
2  * IPWireless 3G PCMCIA Network Driver
3  *
4  * Original code
5  *   by Stephen Blackheath <stephen@blacksapphire.com>,
6  *      Ben Martel <benm@symmetric.co.nz>
7  *
8  * Copyrighted as follows:
9  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
10  *
11  * Various driver changes and rewrites, port to new kernels
12  *   Copyright (C) 2006-2007 Jiri Kosina
13  *
14  * Misc code cleanups and updates
15  *   Copyright (C) 2007 David Sterba
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/ppp_defs.h>
22 #include <linux/if.h>
23 #include <linux/ppp-ioctl.h>
24 #include <linux/sched.h>
25 #include <linux/serial.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/uaccess.h>
31 
32 #include "tty.h"
33 #include "network.h"
34 #include "hardware.h"
35 #include "main.h"
36 
37 #define IPWIRELESS_PCMCIA_START 	(0)
38 #define IPWIRELESS_PCMCIA_MINORS	(24)
39 #define IPWIRELESS_PCMCIA_MINOR_RANGE	(8)
40 
41 #define TTYTYPE_MODEM    (0)
42 #define TTYTYPE_MONITOR  (1)
43 #define TTYTYPE_RAS_RAW  (2)
44 
45 struct ipw_tty {
46 	struct tty_port port;
47 	int index;
48 	struct ipw_hardware *hardware;
49 	unsigned int channel_idx;
50 	unsigned int secondary_channel_idx;
51 	int tty_type;
52 	struct ipw_network *network;
53 	unsigned int control_lines;
54 	struct mutex ipw_tty_mutex;
55 	int tx_bytes_queued;
56 	int closing;
57 };
58 
59 static struct ipw_tty *ttys[IPWIRELESS_PCMCIA_MINORS];
60 
61 static struct tty_driver *ipw_tty_driver;
62 
63 static char *tty_type_name(int tty_type)
64 {
65 	static char *channel_names[] = {
66 		"modem",
67 		"monitor",
68 		"RAS-raw"
69 	};
70 
71 	return channel_names[tty_type];
72 }
73 
74 static struct ipw_tty *get_tty(int index)
75 {
76 	/*
77 	 * The 'ras_raw' channel is only available when 'loopback' mode
78 	 * is enabled.
79 	 * Number of minor starts with 16 (_RANGE * _RAS_RAW).
80 	 */
81 	if (!ipwireless_loopback && index >=
82 			 IPWIRELESS_PCMCIA_MINOR_RANGE * TTYTYPE_RAS_RAW)
83 		return NULL;
84 
85 	return ttys[index];
86 }
87 
88 static int ipw_open(struct tty_struct *linux_tty, struct file *filp)
89 {
90 	struct ipw_tty *tty = get_tty(linux_tty->index);
91 
92 	if (!tty)
93 		return -ENODEV;
94 
95 	mutex_lock(&tty->ipw_tty_mutex);
96 	if (tty->port.count == 0)
97 		tty->tx_bytes_queued = 0;
98 
99 	tty->port.count++;
100 
101 	tty->port.tty = linux_tty;
102 	linux_tty->driver_data = tty;
103 	tty->port.low_latency = 1;
104 
105 	if (tty->tty_type == TTYTYPE_MODEM)
106 		ipwireless_ppp_open(tty->network);
107 
108 	mutex_unlock(&tty->ipw_tty_mutex);
109 
110 	return 0;
111 }
112 
113 static void do_ipw_close(struct ipw_tty *tty)
114 {
115 	tty->port.count--;
116 
117 	if (tty->port.count == 0) {
118 		struct tty_struct *linux_tty = tty->port.tty;
119 
120 		if (linux_tty != NULL) {
121 			tty->port.tty = NULL;
122 			linux_tty->driver_data = NULL;
123 
124 			if (tty->tty_type == TTYTYPE_MODEM)
125 				ipwireless_ppp_close(tty->network);
126 		}
127 	}
128 }
129 
130 static void ipw_hangup(struct tty_struct *linux_tty)
131 {
132 	struct ipw_tty *tty = linux_tty->driver_data;
133 
134 	if (!tty)
135 		return;
136 
137 	mutex_lock(&tty->ipw_tty_mutex);
138 	if (tty->port.count == 0) {
139 		mutex_unlock(&tty->ipw_tty_mutex);
140 		return;
141 	}
142 
143 	do_ipw_close(tty);
144 
145 	mutex_unlock(&tty->ipw_tty_mutex);
146 }
147 
148 static void ipw_close(struct tty_struct *linux_tty, struct file *filp)
149 {
150 	ipw_hangup(linux_tty);
151 }
152 
153 /* Take data received from hardware, and send it out the tty */
154 void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
155 			unsigned int length)
156 {
157 	int work = 0;
158 
159 	mutex_lock(&tty->ipw_tty_mutex);
160 
161 	if (!tty->port.count) {
162 		mutex_unlock(&tty->ipw_tty_mutex);
163 		return;
164 	}
165 	mutex_unlock(&tty->ipw_tty_mutex);
166 
167 	work = tty_insert_flip_string(&tty->port, data, length);
168 
169 	if (work != length)
170 		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
171 				": %d chars not inserted to flip buffer!\n",
172 				length - work);
173 
174 	if (work)
175 		tty_flip_buffer_push(&tty->port);
176 }
177 
178 static void ipw_write_packet_sent_callback(void *callback_data,
179 					   unsigned int packet_length)
180 {
181 	struct ipw_tty *tty = callback_data;
182 
183 	/*
184 	 * Packet has been sent, so we subtract the number of bytes from our
185 	 * tally of outstanding TX bytes.
186 	 */
187 	tty->tx_bytes_queued -= packet_length;
188 }
189 
190 static int ipw_write(struct tty_struct *linux_tty,
191 		     const unsigned char *buf, int count)
192 {
193 	struct ipw_tty *tty = linux_tty->driver_data;
194 	int room, ret;
195 
196 	if (!tty)
197 		return -ENODEV;
198 
199 	mutex_lock(&tty->ipw_tty_mutex);
200 	if (!tty->port.count) {
201 		mutex_unlock(&tty->ipw_tty_mutex);
202 		return -EINVAL;
203 	}
204 
205 	room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
206 	if (room < 0)
207 		room = 0;
208 	/* Don't allow caller to write any more than we have room for */
209 	if (count > room)
210 		count = room;
211 
212 	if (count == 0) {
213 		mutex_unlock(&tty->ipw_tty_mutex);
214 		return 0;
215 	}
216 
217 	ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
218 			       buf, count,
219 			       ipw_write_packet_sent_callback, tty);
220 	if (ret == -1) {
221 		mutex_unlock(&tty->ipw_tty_mutex);
222 		return 0;
223 	}
224 
225 	tty->tx_bytes_queued += count;
226 	mutex_unlock(&tty->ipw_tty_mutex);
227 
228 	return count;
229 }
230 
231 static int ipw_write_room(struct tty_struct *linux_tty)
232 {
233 	struct ipw_tty *tty = linux_tty->driver_data;
234 	int room;
235 
236 	/* FIXME: Exactly how is the tty object locked here .. */
237 	if (!tty)
238 		return -ENODEV;
239 
240 	if (!tty->port.count)
241 		return -EINVAL;
242 
243 	room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
244 	if (room < 0)
245 		room = 0;
246 
247 	return room;
248 }
249 
250 static int ipwireless_get_serial_info(struct ipw_tty *tty,
251 				      struct serial_struct __user *retinfo)
252 {
253 	struct serial_struct tmp;
254 
255 	if (!retinfo)
256 		return (-EFAULT);
257 
258 	memset(&tmp, 0, sizeof(tmp));
259 	tmp.type = PORT_UNKNOWN;
260 	tmp.line = tty->index;
261 	tmp.port = 0;
262 	tmp.irq = 0;
263 	tmp.flags = 0;
264 	tmp.baud_base = 115200;
265 	tmp.close_delay = 0;
266 	tmp.closing_wait = 0;
267 	tmp.custom_divisor = 0;
268 	tmp.hub6 = 0;
269 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
270 		return -EFAULT;
271 
272 	return 0;
273 }
274 
275 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
276 {
277 	struct ipw_tty *tty = linux_tty->driver_data;
278 
279 	if (!tty)
280 		return 0;
281 
282 	if (!tty->port.count)
283 		return 0;
284 
285 	return tty->tx_bytes_queued;
286 }
287 
288 static int get_control_lines(struct ipw_tty *tty)
289 {
290 	unsigned int my = tty->control_lines;
291 	unsigned int out = 0;
292 
293 	if (my & IPW_CONTROL_LINE_RTS)
294 		out |= TIOCM_RTS;
295 	if (my & IPW_CONTROL_LINE_DTR)
296 		out |= TIOCM_DTR;
297 	if (my & IPW_CONTROL_LINE_CTS)
298 		out |= TIOCM_CTS;
299 	if (my & IPW_CONTROL_LINE_DSR)
300 		out |= TIOCM_DSR;
301 	if (my & IPW_CONTROL_LINE_DCD)
302 		out |= TIOCM_CD;
303 
304 	return out;
305 }
306 
307 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
308 			     unsigned int clear)
309 {
310 	int ret;
311 
312 	if (set & TIOCM_RTS) {
313 		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
314 		if (ret)
315 			return ret;
316 		if (tty->secondary_channel_idx != -1) {
317 			ret = ipwireless_set_RTS(tty->hardware,
318 					  tty->secondary_channel_idx, 1);
319 			if (ret)
320 				return ret;
321 		}
322 	}
323 	if (set & TIOCM_DTR) {
324 		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
325 		if (ret)
326 			return ret;
327 		if (tty->secondary_channel_idx != -1) {
328 			ret = ipwireless_set_DTR(tty->hardware,
329 					  tty->secondary_channel_idx, 1);
330 			if (ret)
331 				return ret;
332 		}
333 	}
334 	if (clear & TIOCM_RTS) {
335 		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
336 		if (tty->secondary_channel_idx != -1) {
337 			ret = ipwireless_set_RTS(tty->hardware,
338 					  tty->secondary_channel_idx, 0);
339 			if (ret)
340 				return ret;
341 		}
342 	}
343 	if (clear & TIOCM_DTR) {
344 		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
345 		if (tty->secondary_channel_idx != -1) {
346 			ret = ipwireless_set_DTR(tty->hardware,
347 					  tty->secondary_channel_idx, 0);
348 			if (ret)
349 				return ret;
350 		}
351 	}
352 	return 0;
353 }
354 
355 static int ipw_tiocmget(struct tty_struct *linux_tty)
356 {
357 	struct ipw_tty *tty = linux_tty->driver_data;
358 	/* FIXME: Exactly how is the tty object locked here .. */
359 
360 	if (!tty)
361 		return -ENODEV;
362 
363 	if (!tty->port.count)
364 		return -EINVAL;
365 
366 	return get_control_lines(tty);
367 }
368 
369 static int
370 ipw_tiocmset(struct tty_struct *linux_tty,
371 	     unsigned int set, unsigned int clear)
372 {
373 	struct ipw_tty *tty = linux_tty->driver_data;
374 	/* FIXME: Exactly how is the tty object locked here .. */
375 
376 	if (!tty)
377 		return -ENODEV;
378 
379 	if (!tty->port.count)
380 		return -EINVAL;
381 
382 	return set_control_lines(tty, set, clear);
383 }
384 
385 static int ipw_ioctl(struct tty_struct *linux_tty,
386 		     unsigned int cmd, unsigned long arg)
387 {
388 	struct ipw_tty *tty = linux_tty->driver_data;
389 
390 	if (!tty)
391 		return -ENODEV;
392 
393 	if (!tty->port.count)
394 		return -EINVAL;
395 
396 	/* FIXME: Exactly how is the tty object locked here .. */
397 
398 	switch (cmd) {
399 	case TIOCGSERIAL:
400 		return ipwireless_get_serial_info(tty, (void __user *) arg);
401 
402 	case TIOCSSERIAL:
403 		return 0;	/* Keeps the PCMCIA scripts happy. */
404 	}
405 
406 	if (tty->tty_type == TTYTYPE_MODEM) {
407 		switch (cmd) {
408 		case PPPIOCGCHAN:
409 			{
410 				int chan = ipwireless_ppp_channel_index(
411 							tty->network);
412 
413 				if (chan < 0)
414 					return -ENODEV;
415 				if (put_user(chan, (int __user *) arg))
416 					return -EFAULT;
417 			}
418 			return 0;
419 
420 		case PPPIOCGUNIT:
421 			{
422 				int unit = ipwireless_ppp_unit_number(
423 						tty->network);
424 
425 				if (unit < 0)
426 					return -ENODEV;
427 				if (put_user(unit, (int __user *) arg))
428 					return -EFAULT;
429 			}
430 			return 0;
431 
432 		case FIONREAD:
433 			{
434 				int val = 0;
435 
436 				if (put_user(val, (int __user *) arg))
437 					return -EFAULT;
438 			}
439 			return 0;
440 		case TCFLSH:
441 			return tty_perform_flush(linux_tty, arg);
442 		}
443 	}
444 	return -ENOIOCTLCMD;
445 }
446 
447 static int add_tty(int j,
448 		    struct ipw_hardware *hardware,
449 		    struct ipw_network *network, int channel_idx,
450 		    int secondary_channel_idx, int tty_type)
451 {
452 	ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
453 	if (!ttys[j])
454 		return -ENOMEM;
455 	ttys[j]->index = j;
456 	ttys[j]->hardware = hardware;
457 	ttys[j]->channel_idx = channel_idx;
458 	ttys[j]->secondary_channel_idx = secondary_channel_idx;
459 	ttys[j]->network = network;
460 	ttys[j]->tty_type = tty_type;
461 	mutex_init(&ttys[j]->ipw_tty_mutex);
462 	tty_port_init(&ttys[j]->port);
463 
464 	tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
465 	ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
466 
467 	if (secondary_channel_idx != -1)
468 		ipwireless_associate_network_tty(network,
469 						 secondary_channel_idx,
470 						 ttys[j]);
471 	/* check if we provide raw device (if loopback is enabled) */
472 	if (get_tty(j))
473 		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
474 		       ": registering %s device ttyIPWp%d\n",
475 		       tty_type_name(tty_type), j);
476 
477 	return 0;
478 }
479 
480 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
481 				      struct ipw_network *network)
482 {
483 	int i, j;
484 
485 	for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
486 		int allfree = 1;
487 
488 		for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
489 				j += IPWIRELESS_PCMCIA_MINOR_RANGE)
490 			if (ttys[j] != NULL) {
491 				allfree = 0;
492 				break;
493 			}
494 
495 		if (allfree) {
496 			j = i;
497 
498 			if (add_tty(j, hardware, network,
499 					IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
500 					TTYTYPE_MODEM))
501 				return NULL;
502 
503 			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
504 			if (add_tty(j, hardware, network,
505 					IPW_CHANNEL_DIALLER, -1,
506 					TTYTYPE_MONITOR))
507 				return NULL;
508 
509 			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
510 			if (add_tty(j, hardware, network,
511 					IPW_CHANNEL_RAS, -1,
512 					TTYTYPE_RAS_RAW))
513 				return NULL;
514 
515 			return ttys[i];
516 		}
517 	}
518 	return NULL;
519 }
520 
521 /*
522  * Must be called before ipwireless_network_free().
523  */
524 void ipwireless_tty_free(struct ipw_tty *tty)
525 {
526 	int j;
527 	struct ipw_network *network = ttys[tty->index]->network;
528 
529 	for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
530 			j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
531 		struct ipw_tty *ttyj = ttys[j];
532 
533 		if (ttyj) {
534 			mutex_lock(&ttyj->ipw_tty_mutex);
535 			if (get_tty(j))
536 				printk(KERN_INFO IPWIRELESS_PCCARD_NAME
537 				       ": deregistering %s device ttyIPWp%d\n",
538 				       tty_type_name(ttyj->tty_type), j);
539 			ttyj->closing = 1;
540 			if (ttyj->port.tty != NULL) {
541 				mutex_unlock(&ttyj->ipw_tty_mutex);
542 				tty_vhangup(ttyj->port.tty);
543 				/* FIXME: Exactly how is the tty object locked here
544 				   against a parallel ioctl etc */
545 				/* FIXME2: hangup does not mean all processes
546 				 * are gone */
547 				mutex_lock(&ttyj->ipw_tty_mutex);
548 			}
549 			while (ttyj->port.count)
550 				do_ipw_close(ttyj);
551 			ipwireless_disassociate_network_ttys(network,
552 							     ttyj->channel_idx);
553 			tty_unregister_device(ipw_tty_driver, j);
554 			tty_port_destroy(&ttyj->port);
555 			ttys[j] = NULL;
556 			mutex_unlock(&ttyj->ipw_tty_mutex);
557 			kfree(ttyj);
558 		}
559 	}
560 }
561 
562 static const struct tty_operations tty_ops = {
563 	.open = ipw_open,
564 	.close = ipw_close,
565 	.hangup = ipw_hangup,
566 	.write = ipw_write,
567 	.write_room = ipw_write_room,
568 	.ioctl = ipw_ioctl,
569 	.chars_in_buffer = ipw_chars_in_buffer,
570 	.tiocmget = ipw_tiocmget,
571 	.tiocmset = ipw_tiocmset,
572 };
573 
574 int ipwireless_tty_init(void)
575 {
576 	int result;
577 
578 	ipw_tty_driver = alloc_tty_driver(IPWIRELESS_PCMCIA_MINORS);
579 	if (!ipw_tty_driver)
580 		return -ENOMEM;
581 
582 	ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
583 	ipw_tty_driver->name = "ttyIPWp";
584 	ipw_tty_driver->major = 0;
585 	ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
586 	ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
587 	ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
588 	ipw_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
589 	ipw_tty_driver->init_termios = tty_std_termios;
590 	ipw_tty_driver->init_termios.c_cflag =
591 	    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
592 	ipw_tty_driver->init_termios.c_ispeed = 9600;
593 	ipw_tty_driver->init_termios.c_ospeed = 9600;
594 	tty_set_operations(ipw_tty_driver, &tty_ops);
595 	result = tty_register_driver(ipw_tty_driver);
596 	if (result) {
597 		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
598 		       ": failed to register tty driver\n");
599 		put_tty_driver(ipw_tty_driver);
600 		return result;
601 	}
602 
603 	return 0;
604 }
605 
606 void ipwireless_tty_release(void)
607 {
608 	int ret;
609 
610 	ret = tty_unregister_driver(ipw_tty_driver);
611 	put_tty_driver(ipw_tty_driver);
612 	if (ret != 0)
613 		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
614 			": tty_unregister_driver failed with code %d\n", ret);
615 }
616 
617 int ipwireless_tty_is_modem(struct ipw_tty *tty)
618 {
619 	return tty->tty_type == TTYTYPE_MODEM;
620 }
621 
622 void
623 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
624 					  unsigned int channel_idx,
625 					  unsigned int control_lines,
626 					  unsigned int changed_mask)
627 {
628 	unsigned int old_control_lines = tty->control_lines;
629 
630 	tty->control_lines = (tty->control_lines & ~changed_mask)
631 		| (control_lines & changed_mask);
632 
633 	/*
634 	 * If DCD is de-asserted, we close the tty so pppd can tell that we
635 	 * have gone offline.
636 	 */
637 	if ((old_control_lines & IPW_CONTROL_LINE_DCD)
638 			&& !(tty->control_lines & IPW_CONTROL_LINE_DCD)
639 			&& tty->port.tty) {
640 		tty_hangup(tty->port.tty);
641 	}
642 }
643 
644