1ef751c27ac6d6e11cd4b0b29fe9ce7e07c59df9
[muen/linux.git] / drivers / tty / ipwireless / tty.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IPWireless 3G PCMCIA Network Driver
4  *
5  * Original code
6  *   by Stephen Blackheath <stephen@blacksapphire.com>,
7  *      Ben Martel <benm@symmetric.co.nz>
8  *
9  * Copyrighted as follows:
10  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
11  *
12  * Various driver changes and rewrites, port to new kernels
13  *   Copyright (C) 2006-2007 Jiri Kosina
14  *
15  * Misc code cleanups and updates
16  *   Copyright (C) 2007 David Sterba
17  */
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/ppp_defs.h>
23 #include <linux/if.h>
24 #include <linux/ppp-ioctl.h>
25 #include <linux/sched.h>
26 #include <linux/serial.h>
27 #include <linux/slab.h>
28 #include <linux/tty.h>
29 #include <linux/tty_driver.h>
30 #include <linux/tty_flip.h>
31 #include <linux/uaccess.h>
32
33 #include "tty.h"
34 #include "network.h"
35 #include "hardware.h"
36 #include "main.h"
37
38 #define IPWIRELESS_PCMCIA_START         (0)
39 #define IPWIRELESS_PCMCIA_MINORS        (24)
40 #define IPWIRELESS_PCMCIA_MINOR_RANGE   (8)
41
42 #define TTYTYPE_MODEM    (0)
43 #define TTYTYPE_MONITOR  (1)
44 #define TTYTYPE_RAS_RAW  (2)
45
46 struct ipw_tty {
47         struct tty_port port;
48         int index;
49         struct ipw_hardware *hardware;
50         unsigned int channel_idx;
51         unsigned int secondary_channel_idx;
52         int tty_type;
53         struct ipw_network *network;
54         unsigned int control_lines;
55         struct mutex ipw_tty_mutex;
56         int tx_bytes_queued;
57         int closing;
58 };
59
60 static struct ipw_tty *ttys[IPWIRELESS_PCMCIA_MINORS];
61
62 static struct tty_driver *ipw_tty_driver;
63
64 static char *tty_type_name(int tty_type)
65 {
66         static char *channel_names[] = {
67                 "modem",
68                 "monitor",
69                 "RAS-raw"
70         };
71
72         return channel_names[tty_type];
73 }
74
75 static struct ipw_tty *get_tty(int index)
76 {
77         /*
78          * The 'ras_raw' channel is only available when 'loopback' mode
79          * is enabled.
80          * Number of minor starts with 16 (_RANGE * _RAS_RAW).
81          */
82         if (!ipwireless_loopback && index >=
83                          IPWIRELESS_PCMCIA_MINOR_RANGE * TTYTYPE_RAS_RAW)
84                 return NULL;
85
86         return ttys[index];
87 }
88
89 static int ipw_open(struct tty_struct *linux_tty, struct file *filp)
90 {
91         struct ipw_tty *tty = get_tty(linux_tty->index);
92
93         if (!tty)
94                 return -ENODEV;
95
96         mutex_lock(&tty->ipw_tty_mutex);
97         if (tty->port.count == 0)
98                 tty->tx_bytes_queued = 0;
99
100         tty->port.count++;
101
102         tty->port.tty = linux_tty;
103         linux_tty->driver_data = tty;
104         tty->port.low_latency = 1;
105
106         if (tty->tty_type == TTYTYPE_MODEM)
107                 ipwireless_ppp_open(tty->network);
108
109         mutex_unlock(&tty->ipw_tty_mutex);
110
111         return 0;
112 }
113
114 static void do_ipw_close(struct ipw_tty *tty)
115 {
116         tty->port.count--;
117
118         if (tty->port.count == 0) {
119                 struct tty_struct *linux_tty = tty->port.tty;
120
121                 if (linux_tty != NULL) {
122                         tty->port.tty = NULL;
123                         linux_tty->driver_data = NULL;
124
125                         if (tty->tty_type == TTYTYPE_MODEM)
126                                 ipwireless_ppp_close(tty->network);
127                 }
128         }
129 }
130
131 static void ipw_hangup(struct tty_struct *linux_tty)
132 {
133         struct ipw_tty *tty = linux_tty->driver_data;
134
135         if (!tty)
136                 return;
137
138         mutex_lock(&tty->ipw_tty_mutex);
139         if (tty->port.count == 0) {
140                 mutex_unlock(&tty->ipw_tty_mutex);
141                 return;
142         }
143
144         do_ipw_close(tty);
145
146         mutex_unlock(&tty->ipw_tty_mutex);
147 }
148
149 static void ipw_close(struct tty_struct *linux_tty, struct file *filp)
150 {
151         ipw_hangup(linux_tty);
152 }
153
154 /* Take data received from hardware, and send it out the tty */
155 void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
156                         unsigned int length)
157 {
158         int work = 0;
159
160         mutex_lock(&tty->ipw_tty_mutex);
161
162         if (!tty->port.count) {
163                 mutex_unlock(&tty->ipw_tty_mutex);
164                 return;
165         }
166         mutex_unlock(&tty->ipw_tty_mutex);
167
168         work = tty_insert_flip_string(&tty->port, data, length);
169
170         if (work != length)
171                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
172                                 ": %d chars not inserted to flip buffer!\n",
173                                 length - work);
174
175         if (work)
176                 tty_flip_buffer_push(&tty->port);
177 }
178
179 static void ipw_write_packet_sent_callback(void *callback_data,
180                                            unsigned int packet_length)
181 {
182         struct ipw_tty *tty = callback_data;
183
184         /*
185          * Packet has been sent, so we subtract the number of bytes from our
186          * tally of outstanding TX bytes.
187          */
188         tty->tx_bytes_queued -= packet_length;
189 }
190
191 static int ipw_write(struct tty_struct *linux_tty,
192                      const unsigned char *buf, int count)
193 {
194         struct ipw_tty *tty = linux_tty->driver_data;
195         int room, ret;
196
197         if (!tty)
198                 return -ENODEV;
199
200         mutex_lock(&tty->ipw_tty_mutex);
201         if (!tty->port.count) {
202                 mutex_unlock(&tty->ipw_tty_mutex);
203                 return -EINVAL;
204         }
205
206         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
207         if (room < 0)
208                 room = 0;
209         /* Don't allow caller to write any more than we have room for */
210         if (count > room)
211                 count = room;
212
213         if (count == 0) {
214                 mutex_unlock(&tty->ipw_tty_mutex);
215                 return 0;
216         }
217
218         ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
219                                buf, count,
220                                ipw_write_packet_sent_callback, tty);
221         if (ret == -1) {
222                 mutex_unlock(&tty->ipw_tty_mutex);
223                 return 0;
224         }
225
226         tty->tx_bytes_queued += count;
227         mutex_unlock(&tty->ipw_tty_mutex);
228
229         return count;
230 }
231
232 static int ipw_write_room(struct tty_struct *linux_tty)
233 {
234         struct ipw_tty *tty = linux_tty->driver_data;
235         int room;
236
237         /* FIXME: Exactly how is the tty object locked here .. */
238         if (!tty)
239                 return -ENODEV;
240
241         if (!tty->port.count)
242                 return -EINVAL;
243
244         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
245         if (room < 0)
246                 room = 0;
247
248         return room;
249 }
250
251 static int ipwireless_get_serial_info(struct ipw_tty *tty,
252                                       struct serial_struct __user *retinfo)
253 {
254         struct serial_struct tmp;
255
256         memset(&tmp, 0, sizeof(tmp));
257         tmp.type = PORT_UNKNOWN;
258         tmp.line = tty->index;
259         tmp.baud_base = 115200;
260
261         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
262                 return -EFAULT;
263
264         return 0;
265 }
266
267 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
268 {
269         struct ipw_tty *tty = linux_tty->driver_data;
270
271         if (!tty)
272                 return 0;
273
274         if (!tty->port.count)
275                 return 0;
276
277         return tty->tx_bytes_queued;
278 }
279
280 static int get_control_lines(struct ipw_tty *tty)
281 {
282         unsigned int my = tty->control_lines;
283         unsigned int out = 0;
284
285         if (my & IPW_CONTROL_LINE_RTS)
286                 out |= TIOCM_RTS;
287         if (my & IPW_CONTROL_LINE_DTR)
288                 out |= TIOCM_DTR;
289         if (my & IPW_CONTROL_LINE_CTS)
290                 out |= TIOCM_CTS;
291         if (my & IPW_CONTROL_LINE_DSR)
292                 out |= TIOCM_DSR;
293         if (my & IPW_CONTROL_LINE_DCD)
294                 out |= TIOCM_CD;
295
296         return out;
297 }
298
299 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
300                              unsigned int clear)
301 {
302         int ret;
303
304         if (set & TIOCM_RTS) {
305                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
306                 if (ret)
307                         return ret;
308                 if (tty->secondary_channel_idx != -1) {
309                         ret = ipwireless_set_RTS(tty->hardware,
310                                           tty->secondary_channel_idx, 1);
311                         if (ret)
312                                 return ret;
313                 }
314         }
315         if (set & TIOCM_DTR) {
316                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
317                 if (ret)
318                         return ret;
319                 if (tty->secondary_channel_idx != -1) {
320                         ret = ipwireless_set_DTR(tty->hardware,
321                                           tty->secondary_channel_idx, 1);
322                         if (ret)
323                                 return ret;
324                 }
325         }
326         if (clear & TIOCM_RTS) {
327                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
328                 if (tty->secondary_channel_idx != -1) {
329                         ret = ipwireless_set_RTS(tty->hardware,
330                                           tty->secondary_channel_idx, 0);
331                         if (ret)
332                                 return ret;
333                 }
334         }
335         if (clear & TIOCM_DTR) {
336                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
337                 if (tty->secondary_channel_idx != -1) {
338                         ret = ipwireless_set_DTR(tty->hardware,
339                                           tty->secondary_channel_idx, 0);
340                         if (ret)
341                                 return ret;
342                 }
343         }
344         return 0;
345 }
346
347 static int ipw_tiocmget(struct tty_struct *linux_tty)
348 {
349         struct ipw_tty *tty = linux_tty->driver_data;
350         /* FIXME: Exactly how is the tty object locked here .. */
351
352         if (!tty)
353                 return -ENODEV;
354
355         if (!tty->port.count)
356                 return -EINVAL;
357
358         return get_control_lines(tty);
359 }
360
361 static int
362 ipw_tiocmset(struct tty_struct *linux_tty,
363              unsigned int set, unsigned int clear)
364 {
365         struct ipw_tty *tty = linux_tty->driver_data;
366         /* FIXME: Exactly how is the tty object locked here .. */
367
368         if (!tty)
369                 return -ENODEV;
370
371         if (!tty->port.count)
372                 return -EINVAL;
373
374         return set_control_lines(tty, set, clear);
375 }
376
377 static int ipw_ioctl(struct tty_struct *linux_tty,
378                      unsigned int cmd, unsigned long arg)
379 {
380         struct ipw_tty *tty = linux_tty->driver_data;
381
382         if (!tty)
383                 return -ENODEV;
384
385         if (!tty->port.count)
386                 return -EINVAL;
387
388         /* FIXME: Exactly how is the tty object locked here .. */
389
390         switch (cmd) {
391         case TIOCGSERIAL:
392                 return ipwireless_get_serial_info(tty, (void __user *) arg);
393
394         case TIOCSSERIAL:
395                 return 0;       /* Keeps the PCMCIA scripts happy. */
396         }
397
398         if (tty->tty_type == TTYTYPE_MODEM) {
399                 switch (cmd) {
400                 case PPPIOCGCHAN:
401                         {
402                                 int chan = ipwireless_ppp_channel_index(
403                                                         tty->network);
404
405                                 if (chan < 0)
406                                         return -ENODEV;
407                                 if (put_user(chan, (int __user *) arg))
408                                         return -EFAULT;
409                         }
410                         return 0;
411
412                 case PPPIOCGUNIT:
413                         {
414                                 int unit = ipwireless_ppp_unit_number(
415                                                 tty->network);
416
417                                 if (unit < 0)
418                                         return -ENODEV;
419                                 if (put_user(unit, (int __user *) arg))
420                                         return -EFAULT;
421                         }
422                         return 0;
423
424                 case FIONREAD:
425                         {
426                                 int val = 0;
427
428                                 if (put_user(val, (int __user *) arg))
429                                         return -EFAULT;
430                         }
431                         return 0;
432                 case TCFLSH:
433                         return tty_perform_flush(linux_tty, arg);
434                 }
435         }
436         return -ENOIOCTLCMD;
437 }
438
439 static int add_tty(int j,
440                     struct ipw_hardware *hardware,
441                     struct ipw_network *network, int channel_idx,
442                     int secondary_channel_idx, int tty_type)
443 {
444         ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
445         if (!ttys[j])
446                 return -ENOMEM;
447         ttys[j]->index = j;
448         ttys[j]->hardware = hardware;
449         ttys[j]->channel_idx = channel_idx;
450         ttys[j]->secondary_channel_idx = secondary_channel_idx;
451         ttys[j]->network = network;
452         ttys[j]->tty_type = tty_type;
453         mutex_init(&ttys[j]->ipw_tty_mutex);
454         tty_port_init(&ttys[j]->port);
455
456         tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
457         ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
458
459         if (secondary_channel_idx != -1)
460                 ipwireless_associate_network_tty(network,
461                                                  secondary_channel_idx,
462                                                  ttys[j]);
463         /* check if we provide raw device (if loopback is enabled) */
464         if (get_tty(j))
465                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
466                        ": registering %s device ttyIPWp%d\n",
467                        tty_type_name(tty_type), j);
468
469         return 0;
470 }
471
472 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
473                                       struct ipw_network *network)
474 {
475         int i, j;
476
477         for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
478                 int allfree = 1;
479
480                 for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
481                                 j += IPWIRELESS_PCMCIA_MINOR_RANGE)
482                         if (ttys[j] != NULL) {
483                                 allfree = 0;
484                                 break;
485                         }
486
487                 if (allfree) {
488                         j = i;
489
490                         if (add_tty(j, hardware, network,
491                                         IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
492                                         TTYTYPE_MODEM))
493                                 return NULL;
494
495                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
496                         if (add_tty(j, hardware, network,
497                                         IPW_CHANNEL_DIALLER, -1,
498                                         TTYTYPE_MONITOR))
499                                 return NULL;
500
501                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
502                         if (add_tty(j, hardware, network,
503                                         IPW_CHANNEL_RAS, -1,
504                                         TTYTYPE_RAS_RAW))
505                                 return NULL;
506
507                         return ttys[i];
508                 }
509         }
510         return NULL;
511 }
512
513 /*
514  * Must be called before ipwireless_network_free().
515  */
516 void ipwireless_tty_free(struct ipw_tty *tty)
517 {
518         int j;
519         struct ipw_network *network = ttys[tty->index]->network;
520
521         for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
522                         j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
523                 struct ipw_tty *ttyj = ttys[j];
524
525                 if (ttyj) {
526                         mutex_lock(&ttyj->ipw_tty_mutex);
527                         if (get_tty(j))
528                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
529                                        ": deregistering %s device ttyIPWp%d\n",
530                                        tty_type_name(ttyj->tty_type), j);
531                         ttyj->closing = 1;
532                         if (ttyj->port.tty != NULL) {
533                                 mutex_unlock(&ttyj->ipw_tty_mutex);
534                                 tty_vhangup(ttyj->port.tty);
535                                 /* FIXME: Exactly how is the tty object locked here
536                                    against a parallel ioctl etc */
537                                 /* FIXME2: hangup does not mean all processes
538                                  * are gone */
539                                 mutex_lock(&ttyj->ipw_tty_mutex);
540                         }
541                         while (ttyj->port.count)
542                                 do_ipw_close(ttyj);
543                         ipwireless_disassociate_network_ttys(network,
544                                                              ttyj->channel_idx);
545                         tty_unregister_device(ipw_tty_driver, j);
546                         tty_port_destroy(&ttyj->port);
547                         ttys[j] = NULL;
548                         mutex_unlock(&ttyj->ipw_tty_mutex);
549                         kfree(ttyj);
550                 }
551         }
552 }
553
554 static const struct tty_operations tty_ops = {
555         .open = ipw_open,
556         .close = ipw_close,
557         .hangup = ipw_hangup,
558         .write = ipw_write,
559         .write_room = ipw_write_room,
560         .ioctl = ipw_ioctl,
561         .chars_in_buffer = ipw_chars_in_buffer,
562         .tiocmget = ipw_tiocmget,
563         .tiocmset = ipw_tiocmset,
564 };
565
566 int ipwireless_tty_init(void)
567 {
568         int result;
569
570         ipw_tty_driver = alloc_tty_driver(IPWIRELESS_PCMCIA_MINORS);
571         if (!ipw_tty_driver)
572                 return -ENOMEM;
573
574         ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
575         ipw_tty_driver->name = "ttyIPWp";
576         ipw_tty_driver->major = 0;
577         ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
578         ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
579         ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
580         ipw_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
581         ipw_tty_driver->init_termios = tty_std_termios;
582         ipw_tty_driver->init_termios.c_cflag =
583             B9600 | CS8 | CREAD | HUPCL | CLOCAL;
584         ipw_tty_driver->init_termios.c_ispeed = 9600;
585         ipw_tty_driver->init_termios.c_ospeed = 9600;
586         tty_set_operations(ipw_tty_driver, &tty_ops);
587         result = tty_register_driver(ipw_tty_driver);
588         if (result) {
589                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
590                        ": failed to register tty driver\n");
591                 put_tty_driver(ipw_tty_driver);
592                 return result;
593         }
594
595         return 0;
596 }
597
598 void ipwireless_tty_release(void)
599 {
600         int ret;
601
602         ret = tty_unregister_driver(ipw_tty_driver);
603         put_tty_driver(ipw_tty_driver);
604         if (ret != 0)
605                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
606                         ": tty_unregister_driver failed with code %d\n", ret);
607 }
608
609 int ipwireless_tty_is_modem(struct ipw_tty *tty)
610 {
611         return tty->tty_type == TTYTYPE_MODEM;
612 }
613
614 void
615 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
616                                           unsigned int channel_idx,
617                                           unsigned int control_lines,
618                                           unsigned int changed_mask)
619 {
620         unsigned int old_control_lines = tty->control_lines;
621
622         tty->control_lines = (tty->control_lines & ~changed_mask)
623                 | (control_lines & changed_mask);
624
625         /*
626          * If DCD is de-asserted, we close the tty so pppd can tell that we
627          * have gone offline.
628          */
629         if ((old_control_lines & IPW_CONTROL_LINE_DCD)
630                         && !(tty->control_lines & IPW_CONTROL_LINE_DCD)
631                         && tty->port.tty) {
632                 tty_hangup(tty->port.tty);
633         }
634 }
635