xref: /openbmc/linux/drivers/tty/ipwireless/tty.c (revision 4f6cce39)
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 	memset(&tmp, 0, sizeof(tmp));
256 	tmp.type = PORT_UNKNOWN;
257 	tmp.line = tty->index;
258 	tmp.baud_base = 115200;
259 
260 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
261 		return -EFAULT;
262 
263 	return 0;
264 }
265 
266 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
267 {
268 	struct ipw_tty *tty = linux_tty->driver_data;
269 
270 	if (!tty)
271 		return 0;
272 
273 	if (!tty->port.count)
274 		return 0;
275 
276 	return tty->tx_bytes_queued;
277 }
278 
279 static int get_control_lines(struct ipw_tty *tty)
280 {
281 	unsigned int my = tty->control_lines;
282 	unsigned int out = 0;
283 
284 	if (my & IPW_CONTROL_LINE_RTS)
285 		out |= TIOCM_RTS;
286 	if (my & IPW_CONTROL_LINE_DTR)
287 		out |= TIOCM_DTR;
288 	if (my & IPW_CONTROL_LINE_CTS)
289 		out |= TIOCM_CTS;
290 	if (my & IPW_CONTROL_LINE_DSR)
291 		out |= TIOCM_DSR;
292 	if (my & IPW_CONTROL_LINE_DCD)
293 		out |= TIOCM_CD;
294 
295 	return out;
296 }
297 
298 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
299 			     unsigned int clear)
300 {
301 	int ret;
302 
303 	if (set & TIOCM_RTS) {
304 		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
305 		if (ret)
306 			return ret;
307 		if (tty->secondary_channel_idx != -1) {
308 			ret = ipwireless_set_RTS(tty->hardware,
309 					  tty->secondary_channel_idx, 1);
310 			if (ret)
311 				return ret;
312 		}
313 	}
314 	if (set & TIOCM_DTR) {
315 		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
316 		if (ret)
317 			return ret;
318 		if (tty->secondary_channel_idx != -1) {
319 			ret = ipwireless_set_DTR(tty->hardware,
320 					  tty->secondary_channel_idx, 1);
321 			if (ret)
322 				return ret;
323 		}
324 	}
325 	if (clear & TIOCM_RTS) {
326 		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
327 		if (tty->secondary_channel_idx != -1) {
328 			ret = ipwireless_set_RTS(tty->hardware,
329 					  tty->secondary_channel_idx, 0);
330 			if (ret)
331 				return ret;
332 		}
333 	}
334 	if (clear & TIOCM_DTR) {
335 		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
336 		if (tty->secondary_channel_idx != -1) {
337 			ret = ipwireless_set_DTR(tty->hardware,
338 					  tty->secondary_channel_idx, 0);
339 			if (ret)
340 				return ret;
341 		}
342 	}
343 	return 0;
344 }
345 
346 static int ipw_tiocmget(struct tty_struct *linux_tty)
347 {
348 	struct ipw_tty *tty = linux_tty->driver_data;
349 	/* FIXME: Exactly how is the tty object locked here .. */
350 
351 	if (!tty)
352 		return -ENODEV;
353 
354 	if (!tty->port.count)
355 		return -EINVAL;
356 
357 	return get_control_lines(tty);
358 }
359 
360 static int
361 ipw_tiocmset(struct tty_struct *linux_tty,
362 	     unsigned int set, unsigned int clear)
363 {
364 	struct ipw_tty *tty = linux_tty->driver_data;
365 	/* FIXME: Exactly how is the tty object locked here .. */
366 
367 	if (!tty)
368 		return -ENODEV;
369 
370 	if (!tty->port.count)
371 		return -EINVAL;
372 
373 	return set_control_lines(tty, set, clear);
374 }
375 
376 static int ipw_ioctl(struct tty_struct *linux_tty,
377 		     unsigned int cmd, unsigned long arg)
378 {
379 	struct ipw_tty *tty = linux_tty->driver_data;
380 
381 	if (!tty)
382 		return -ENODEV;
383 
384 	if (!tty->port.count)
385 		return -EINVAL;
386 
387 	/* FIXME: Exactly how is the tty object locked here .. */
388 
389 	switch (cmd) {
390 	case TIOCGSERIAL:
391 		return ipwireless_get_serial_info(tty, (void __user *) arg);
392 
393 	case TIOCSSERIAL:
394 		return 0;	/* Keeps the PCMCIA scripts happy. */
395 	}
396 
397 	if (tty->tty_type == TTYTYPE_MODEM) {
398 		switch (cmd) {
399 		case PPPIOCGCHAN:
400 			{
401 				int chan = ipwireless_ppp_channel_index(
402 							tty->network);
403 
404 				if (chan < 0)
405 					return -ENODEV;
406 				if (put_user(chan, (int __user *) arg))
407 					return -EFAULT;
408 			}
409 			return 0;
410 
411 		case PPPIOCGUNIT:
412 			{
413 				int unit = ipwireless_ppp_unit_number(
414 						tty->network);
415 
416 				if (unit < 0)
417 					return -ENODEV;
418 				if (put_user(unit, (int __user *) arg))
419 					return -EFAULT;
420 			}
421 			return 0;
422 
423 		case FIONREAD:
424 			{
425 				int val = 0;
426 
427 				if (put_user(val, (int __user *) arg))
428 					return -EFAULT;
429 			}
430 			return 0;
431 		case TCFLSH:
432 			return tty_perform_flush(linux_tty, arg);
433 		}
434 	}
435 	return -ENOIOCTLCMD;
436 }
437 
438 static int add_tty(int j,
439 		    struct ipw_hardware *hardware,
440 		    struct ipw_network *network, int channel_idx,
441 		    int secondary_channel_idx, int tty_type)
442 {
443 	ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
444 	if (!ttys[j])
445 		return -ENOMEM;
446 	ttys[j]->index = j;
447 	ttys[j]->hardware = hardware;
448 	ttys[j]->channel_idx = channel_idx;
449 	ttys[j]->secondary_channel_idx = secondary_channel_idx;
450 	ttys[j]->network = network;
451 	ttys[j]->tty_type = tty_type;
452 	mutex_init(&ttys[j]->ipw_tty_mutex);
453 	tty_port_init(&ttys[j]->port);
454 
455 	tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
456 	ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
457 
458 	if (secondary_channel_idx != -1)
459 		ipwireless_associate_network_tty(network,
460 						 secondary_channel_idx,
461 						 ttys[j]);
462 	/* check if we provide raw device (if loopback is enabled) */
463 	if (get_tty(j))
464 		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
465 		       ": registering %s device ttyIPWp%d\n",
466 		       tty_type_name(tty_type), j);
467 
468 	return 0;
469 }
470 
471 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
472 				      struct ipw_network *network)
473 {
474 	int i, j;
475 
476 	for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
477 		int allfree = 1;
478 
479 		for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
480 				j += IPWIRELESS_PCMCIA_MINOR_RANGE)
481 			if (ttys[j] != NULL) {
482 				allfree = 0;
483 				break;
484 			}
485 
486 		if (allfree) {
487 			j = i;
488 
489 			if (add_tty(j, hardware, network,
490 					IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
491 					TTYTYPE_MODEM))
492 				return NULL;
493 
494 			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
495 			if (add_tty(j, hardware, network,
496 					IPW_CHANNEL_DIALLER, -1,
497 					TTYTYPE_MONITOR))
498 				return NULL;
499 
500 			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
501 			if (add_tty(j, hardware, network,
502 					IPW_CHANNEL_RAS, -1,
503 					TTYTYPE_RAS_RAW))
504 				return NULL;
505 
506 			return ttys[i];
507 		}
508 	}
509 	return NULL;
510 }
511 
512 /*
513  * Must be called before ipwireless_network_free().
514  */
515 void ipwireless_tty_free(struct ipw_tty *tty)
516 {
517 	int j;
518 	struct ipw_network *network = ttys[tty->index]->network;
519 
520 	for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
521 			j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
522 		struct ipw_tty *ttyj = ttys[j];
523 
524 		if (ttyj) {
525 			mutex_lock(&ttyj->ipw_tty_mutex);
526 			if (get_tty(j))
527 				printk(KERN_INFO IPWIRELESS_PCCARD_NAME
528 				       ": deregistering %s device ttyIPWp%d\n",
529 				       tty_type_name(ttyj->tty_type), j);
530 			ttyj->closing = 1;
531 			if (ttyj->port.tty != NULL) {
532 				mutex_unlock(&ttyj->ipw_tty_mutex);
533 				tty_vhangup(ttyj->port.tty);
534 				/* FIXME: Exactly how is the tty object locked here
535 				   against a parallel ioctl etc */
536 				/* FIXME2: hangup does not mean all processes
537 				 * are gone */
538 				mutex_lock(&ttyj->ipw_tty_mutex);
539 			}
540 			while (ttyj->port.count)
541 				do_ipw_close(ttyj);
542 			ipwireless_disassociate_network_ttys(network,
543 							     ttyj->channel_idx);
544 			tty_unregister_device(ipw_tty_driver, j);
545 			tty_port_destroy(&ttyj->port);
546 			ttys[j] = NULL;
547 			mutex_unlock(&ttyj->ipw_tty_mutex);
548 			kfree(ttyj);
549 		}
550 	}
551 }
552 
553 static const struct tty_operations tty_ops = {
554 	.open = ipw_open,
555 	.close = ipw_close,
556 	.hangup = ipw_hangup,
557 	.write = ipw_write,
558 	.write_room = ipw_write_room,
559 	.ioctl = ipw_ioctl,
560 	.chars_in_buffer = ipw_chars_in_buffer,
561 	.tiocmget = ipw_tiocmget,
562 	.tiocmset = ipw_tiocmset,
563 };
564 
565 int ipwireless_tty_init(void)
566 {
567 	int result;
568 
569 	ipw_tty_driver = alloc_tty_driver(IPWIRELESS_PCMCIA_MINORS);
570 	if (!ipw_tty_driver)
571 		return -ENOMEM;
572 
573 	ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
574 	ipw_tty_driver->name = "ttyIPWp";
575 	ipw_tty_driver->major = 0;
576 	ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
577 	ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
578 	ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
579 	ipw_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
580 	ipw_tty_driver->init_termios = tty_std_termios;
581 	ipw_tty_driver->init_termios.c_cflag =
582 	    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
583 	ipw_tty_driver->init_termios.c_ispeed = 9600;
584 	ipw_tty_driver->init_termios.c_ospeed = 9600;
585 	tty_set_operations(ipw_tty_driver, &tty_ops);
586 	result = tty_register_driver(ipw_tty_driver);
587 	if (result) {
588 		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
589 		       ": failed to register tty driver\n");
590 		put_tty_driver(ipw_tty_driver);
591 		return result;
592 	}
593 
594 	return 0;
595 }
596 
597 void ipwireless_tty_release(void)
598 {
599 	int ret;
600 
601 	ret = tty_unregister_driver(ipw_tty_driver);
602 	put_tty_driver(ipw_tty_driver);
603 	if (ret != 0)
604 		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
605 			": tty_unregister_driver failed with code %d\n", ret);
606 }
607 
608 int ipwireless_tty_is_modem(struct ipw_tty *tty)
609 {
610 	return tty->tty_type == TTYTYPE_MODEM;
611 }
612 
613 void
614 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
615 					  unsigned int channel_idx,
616 					  unsigned int control_lines,
617 					  unsigned int changed_mask)
618 {
619 	unsigned int old_control_lines = tty->control_lines;
620 
621 	tty->control_lines = (tty->control_lines & ~changed_mask)
622 		| (control_lines & changed_mask);
623 
624 	/*
625 	 * If DCD is de-asserted, we close the tty so pppd can tell that we
626 	 * have gone offline.
627 	 */
628 	if ((old_control_lines & IPW_CONTROL_LINE_DCD)
629 			&& !(tty->control_lines & IPW_CONTROL_LINE_DCD)
630 			&& tty->port.tty) {
631 		tty_hangup(tty->port.tty);
632 	}
633 }
634 
635