1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * interface to user space for the gigaset driver
4 *
5 * Copyright (c) 2004 by Hansjoerg Lipp <hjlipp@web.de>
6 *
7 * =====================================================================
8 * =====================================================================
9 */
10
11 #include "gigaset.h"
12 #include <linux/gigaset_dev.h>
13 #include <linux/tty_flip.h>
14 #include <linux/module.h>
15
16 /*** our ioctls ***/
17
if_lock(struct cardstate * cs,int * arg)18 static int if_lock(struct cardstate *cs, int *arg)
19 {
20 int cmd = *arg;
21
22 gig_dbg(DEBUG_IF, "%u: if_lock (%d)", cs->minor_index, cmd);
23
24 if (cmd > 1)
25 return -EINVAL;
26
27 if (cmd < 0) {
28 *arg = cs->mstate == MS_LOCKED;
29 return 0;
30 }
31
32 if (!cmd && cs->mstate == MS_LOCKED && cs->connected) {
33 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR | TIOCM_RTS);
34 cs->ops->baud_rate(cs, B115200);
35 cs->ops->set_line_ctrl(cs, CS8);
36 cs->control_state = TIOCM_DTR | TIOCM_RTS;
37 }
38
39 cs->waiting = 1;
40 if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
41 NULL, cmd, NULL)) {
42 cs->waiting = 0;
43 return -ENOMEM;
44 }
45 gigaset_schedule_event(cs);
46
47 wait_event(cs->waitqueue, !cs->waiting);
48
49 if (cs->cmd_result >= 0) {
50 *arg = cs->cmd_result;
51 return 0;
52 }
53
54 return cs->cmd_result;
55 }
56
if_version(struct cardstate * cs,unsigned arg[4])57 static int if_version(struct cardstate *cs, unsigned arg[4])
58 {
59 static const unsigned version[4] = GIG_VERSION;
60 static const unsigned compat[4] = GIG_COMPAT;
61 unsigned cmd = arg[0];
62
63 gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
64
65 switch (cmd) {
66 case GIGVER_DRIVER:
67 memcpy(arg, version, sizeof version);
68 return 0;
69 case GIGVER_COMPAT:
70 memcpy(arg, compat, sizeof compat);
71 return 0;
72 case GIGVER_FWBASE:
73 cs->waiting = 1;
74 if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
75 NULL, 0, arg)) {
76 cs->waiting = 0;
77 return -ENOMEM;
78 }
79 gigaset_schedule_event(cs);
80
81 wait_event(cs->waitqueue, !cs->waiting);
82
83 if (cs->cmd_result >= 0)
84 return 0;
85
86 return cs->cmd_result;
87 default:
88 return -EINVAL;
89 }
90 }
91
if_config(struct cardstate * cs,int * arg)92 static int if_config(struct cardstate *cs, int *arg)
93 {
94 gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
95
96 if (*arg != 1)
97 return -EINVAL;
98
99 if (cs->mstate != MS_LOCKED)
100 return -EBUSY;
101
102 if (!cs->connected) {
103 pr_err("%s: not connected\n", __func__);
104 return -ENODEV;
105 }
106
107 *arg = 0;
108 return gigaset_enterconfigmode(cs);
109 }
110
111 /*** the terminal driver ***/
112
if_open(struct tty_struct * tty,struct file * filp)113 static int if_open(struct tty_struct *tty, struct file *filp)
114 {
115 struct cardstate *cs;
116
117 gig_dbg(DEBUG_IF, "%d+%d: %s()",
118 tty->driver->minor_start, tty->index, __func__);
119
120 cs = gigaset_get_cs_by_tty(tty);
121 if (!cs || !try_module_get(cs->driver->owner))
122 return -ENODEV;
123
124 if (mutex_lock_interruptible(&cs->mutex)) {
125 module_put(cs->driver->owner);
126 return -ERESTARTSYS;
127 }
128 tty->driver_data = cs;
129
130 ++cs->port.count;
131
132 if (cs->port.count == 1) {
133 tty_port_tty_set(&cs->port, tty);
134 cs->port.low_latency = 1;
135 }
136
137 mutex_unlock(&cs->mutex);
138 return 0;
139 }
140
if_close(struct tty_struct * tty,struct file * filp)141 static void if_close(struct tty_struct *tty, struct file *filp)
142 {
143 struct cardstate *cs = tty->driver_data;
144
145 if (!cs) { /* happens if we didn't find cs in open */
146 gig_dbg(DEBUG_IF, "%s: no cardstate", __func__);
147 return;
148 }
149
150 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
151
152 mutex_lock(&cs->mutex);
153
154 if (!cs->connected)
155 gig_dbg(DEBUG_IF, "not connected"); /* nothing to do */
156 else if (!cs->port.count)
157 dev_warn(cs->dev, "%s: device not opened\n", __func__);
158 else if (!--cs->port.count)
159 tty_port_tty_set(&cs->port, NULL);
160
161 mutex_unlock(&cs->mutex);
162
163 module_put(cs->driver->owner);
164 }
165
if_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)166 static int if_ioctl(struct tty_struct *tty,
167 unsigned int cmd, unsigned long arg)
168 {
169 struct cardstate *cs = tty->driver_data;
170 int retval = -ENODEV;
171 int int_arg;
172 unsigned char buf[6];
173 unsigned version[4];
174
175 gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
176
177 if (mutex_lock_interruptible(&cs->mutex))
178 return -ERESTARTSYS;
179
180 if (!cs->connected) {
181 gig_dbg(DEBUG_IF, "not connected");
182 retval = -ENODEV;
183 } else {
184 retval = 0;
185 switch (cmd) {
186 case GIGASET_REDIR:
187 retval = get_user(int_arg, (int __user *) arg);
188 if (retval >= 0)
189 retval = if_lock(cs, &int_arg);
190 if (retval >= 0)
191 retval = put_user(int_arg, (int __user *) arg);
192 break;
193 case GIGASET_CONFIG:
194 retval = get_user(int_arg, (int __user *) arg);
195 if (retval >= 0)
196 retval = if_config(cs, &int_arg);
197 if (retval >= 0)
198 retval = put_user(int_arg, (int __user *) arg);
199 break;
200 case GIGASET_BRKCHARS:
201 retval = copy_from_user(&buf,
202 (const unsigned char __user *) arg, 6)
203 ? -EFAULT : 0;
204 if (retval >= 0) {
205 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
206 6, buf);
207 retval = cs->ops->brkchars(cs, buf);
208 }
209 break;
210 case GIGASET_VERSION:
211 retval = copy_from_user(version,
212 (unsigned __user *) arg, sizeof version)
213 ? -EFAULT : 0;
214 if (retval >= 0)
215 retval = if_version(cs, version);
216 if (retval >= 0)
217 retval = copy_to_user((unsigned __user *) arg,
218 version, sizeof version)
219 ? -EFAULT : 0;
220 break;
221 default:
222 gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
223 __func__, cmd);
224 retval = -ENOIOCTLCMD;
225 }
226 }
227
228 mutex_unlock(&cs->mutex);
229
230 return retval;
231 }
232
233 #ifdef CONFIG_COMPAT
if_compat_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)234 static long if_compat_ioctl(struct tty_struct *tty,
235 unsigned int cmd, unsigned long arg)
236 {
237 return if_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
238 }
239 #endif
240
if_tiocmget(struct tty_struct * tty)241 static int if_tiocmget(struct tty_struct *tty)
242 {
243 struct cardstate *cs = tty->driver_data;
244 int retval;
245
246 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
247
248 if (mutex_lock_interruptible(&cs->mutex))
249 return -ERESTARTSYS;
250
251 retval = cs->control_state & (TIOCM_RTS | TIOCM_DTR);
252
253 mutex_unlock(&cs->mutex);
254
255 return retval;
256 }
257
if_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)258 static int if_tiocmset(struct tty_struct *tty,
259 unsigned int set, unsigned int clear)
260 {
261 struct cardstate *cs = tty->driver_data;
262 int retval;
263 unsigned mc;
264
265 gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
266 cs->minor_index, __func__, set, clear);
267
268 if (mutex_lock_interruptible(&cs->mutex))
269 return -ERESTARTSYS;
270
271 if (!cs->connected) {
272 gig_dbg(DEBUG_IF, "not connected");
273 retval = -ENODEV;
274 } else {
275 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS | TIOCM_DTR);
276 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
277 cs->control_state = mc;
278 }
279
280 mutex_unlock(&cs->mutex);
281
282 return retval;
283 }
284
if_write(struct tty_struct * tty,const unsigned char * buf,int count)285 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
286 {
287 struct cardstate *cs = tty->driver_data;
288 struct cmdbuf_t *cb;
289 int retval;
290
291 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
292
293 if (mutex_lock_interruptible(&cs->mutex))
294 return -ERESTARTSYS;
295
296 if (!cs->connected) {
297 gig_dbg(DEBUG_IF, "not connected");
298 retval = -ENODEV;
299 goto done;
300 }
301 if (cs->mstate != MS_LOCKED) {
302 dev_warn(cs->dev, "can't write to unlocked device\n");
303 retval = -EBUSY;
304 goto done;
305 }
306 if (count <= 0) {
307 /* nothing to do */
308 retval = 0;
309 goto done;
310 }
311
312 cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
313 if (!cb) {
314 dev_err(cs->dev, "%s: out of memory\n", __func__);
315 retval = -ENOMEM;
316 goto done;
317 }
318
319 memcpy(cb->buf, buf, count);
320 cb->len = count;
321 cb->offset = 0;
322 cb->next = NULL;
323 cb->wake_tasklet = &cs->if_wake_tasklet;
324 retval = cs->ops->write_cmd(cs, cb);
325 done:
326 mutex_unlock(&cs->mutex);
327 return retval;
328 }
329
if_write_room(struct tty_struct * tty)330 static int if_write_room(struct tty_struct *tty)
331 {
332 struct cardstate *cs = tty->driver_data;
333 int retval;
334
335 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
336
337 if (mutex_lock_interruptible(&cs->mutex))
338 return -ERESTARTSYS;
339
340 if (!cs->connected) {
341 gig_dbg(DEBUG_IF, "not connected");
342 retval = -ENODEV;
343 } else if (cs->mstate != MS_LOCKED) {
344 dev_warn(cs->dev, "can't write to unlocked device\n");
345 retval = -EBUSY;
346 } else
347 retval = cs->ops->write_room(cs);
348
349 mutex_unlock(&cs->mutex);
350
351 return retval;
352 }
353
if_chars_in_buffer(struct tty_struct * tty)354 static int if_chars_in_buffer(struct tty_struct *tty)
355 {
356 struct cardstate *cs = tty->driver_data;
357 int retval = 0;
358
359 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
360
361 mutex_lock(&cs->mutex);
362
363 if (!cs->connected)
364 gig_dbg(DEBUG_IF, "not connected");
365 else if (cs->mstate != MS_LOCKED)
366 dev_warn(cs->dev, "can't write to unlocked device\n");
367 else
368 retval = cs->ops->chars_in_buffer(cs);
369
370 mutex_unlock(&cs->mutex);
371
372 return retval;
373 }
374
if_throttle(struct tty_struct * tty)375 static void if_throttle(struct tty_struct *tty)
376 {
377 struct cardstate *cs = tty->driver_data;
378
379 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
380
381 mutex_lock(&cs->mutex);
382
383 if (!cs->connected)
384 gig_dbg(DEBUG_IF, "not connected"); /* nothing to do */
385 else
386 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
387
388 mutex_unlock(&cs->mutex);
389 }
390
if_unthrottle(struct tty_struct * tty)391 static void if_unthrottle(struct tty_struct *tty)
392 {
393 struct cardstate *cs = tty->driver_data;
394
395 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
396
397 mutex_lock(&cs->mutex);
398
399 if (!cs->connected)
400 gig_dbg(DEBUG_IF, "not connected"); /* nothing to do */
401 else
402 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
403
404 mutex_unlock(&cs->mutex);
405 }
406
if_set_termios(struct tty_struct * tty,struct ktermios * old)407 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
408 {
409 struct cardstate *cs = tty->driver_data;
410 unsigned int iflag;
411 unsigned int cflag;
412 unsigned int old_cflag;
413 unsigned int control_state, new_state;
414
415 gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
416
417 mutex_lock(&cs->mutex);
418
419 if (!cs->connected) {
420 gig_dbg(DEBUG_IF, "not connected");
421 goto out;
422 }
423
424 iflag = tty->termios.c_iflag;
425 cflag = tty->termios.c_cflag;
426 old_cflag = old ? old->c_cflag : cflag;
427 gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
428 cs->minor_index, iflag, cflag, old_cflag);
429
430 /* get a local copy of the current port settings */
431 control_state = cs->control_state;
432
433 /*
434 * Update baud rate.
435 * Do not attempt to cache old rates and skip settings,
436 * disconnects screw such tricks up completely.
437 * Premature optimization is the root of all evil.
438 */
439
440 /* reassert DTR and (maybe) RTS on transition from B0 */
441 if ((old_cflag & CBAUD) == B0) {
442 new_state = control_state | TIOCM_DTR;
443 /* don't set RTS if using hardware flow control */
444 if (!(old_cflag & CRTSCTS))
445 new_state |= TIOCM_RTS;
446 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
447 cs->minor_index,
448 (new_state & TIOCM_RTS) ? " only" : "/RTS");
449 cs->ops->set_modem_ctrl(cs, control_state, new_state);
450 control_state = new_state;
451 }
452
453 cs->ops->baud_rate(cs, cflag & CBAUD);
454
455 if ((cflag & CBAUD) == B0) {
456 /* Drop RTS and DTR */
457 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
458 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
459 cs->ops->set_modem_ctrl(cs, control_state, new_state);
460 control_state = new_state;
461 }
462
463 /*
464 * Update line control register (LCR)
465 */
466
467 cs->ops->set_line_ctrl(cs, cflag);
468
469 /* save off the modified port settings */
470 cs->control_state = control_state;
471
472 out:
473 mutex_unlock(&cs->mutex);
474 }
475
476 static const struct tty_operations if_ops = {
477 .open = if_open,
478 .close = if_close,
479 .ioctl = if_ioctl,
480 #ifdef CONFIG_COMPAT
481 .compat_ioctl = if_compat_ioctl,
482 #endif
483 .write = if_write,
484 .write_room = if_write_room,
485 .chars_in_buffer = if_chars_in_buffer,
486 .set_termios = if_set_termios,
487 .throttle = if_throttle,
488 .unthrottle = if_unthrottle,
489 .tiocmget = if_tiocmget,
490 .tiocmset = if_tiocmset,
491 };
492
493
494 /* wakeup tasklet for the write operation */
if_wake(unsigned long data)495 static void if_wake(unsigned long data)
496 {
497 struct cardstate *cs = (struct cardstate *)data;
498
499 tty_port_tty_wakeup(&cs->port);
500 }
501
502 /*** interface to common ***/
503
gigaset_if_init(struct cardstate * cs)504 void gigaset_if_init(struct cardstate *cs)
505 {
506 struct gigaset_driver *drv;
507
508 drv = cs->driver;
509 if (!drv->have_tty)
510 return;
511
512 tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
513
514 mutex_lock(&cs->mutex);
515 cs->tty_dev = tty_port_register_device(&cs->port, drv->tty,
516 cs->minor_index, NULL);
517
518 if (!IS_ERR(cs->tty_dev))
519 dev_set_drvdata(cs->tty_dev, cs);
520 else {
521 pr_warning("could not register device to the tty subsystem\n");
522 cs->tty_dev = NULL;
523 }
524 mutex_unlock(&cs->mutex);
525 }
526
gigaset_if_free(struct cardstate * cs)527 void gigaset_if_free(struct cardstate *cs)
528 {
529 struct gigaset_driver *drv;
530
531 drv = cs->driver;
532 if (!drv->have_tty)
533 return;
534
535 tasklet_disable(&cs->if_wake_tasklet);
536 tasklet_kill(&cs->if_wake_tasklet);
537 cs->tty_dev = NULL;
538 tty_unregister_device(drv->tty, cs->minor_index);
539 }
540
541 /**
542 * gigaset_if_receive() - pass a received block of data to the tty device
543 * @cs: device descriptor structure.
544 * @buffer: received data.
545 * @len: number of bytes received.
546 *
547 * Called by asyncdata/isocdata if a block of data received from the
548 * device must be sent to userspace through the ttyG* device.
549 */
gigaset_if_receive(struct cardstate * cs,unsigned char * buffer,size_t len)550 void gigaset_if_receive(struct cardstate *cs,
551 unsigned char *buffer, size_t len)
552 {
553 tty_insert_flip_string(&cs->port, buffer, len);
554 tty_flip_buffer_push(&cs->port);
555 }
556 EXPORT_SYMBOL_GPL(gigaset_if_receive);
557
558 /* gigaset_if_initdriver
559 * Initialize tty interface.
560 * parameters:
561 * drv Driver
562 * procname Name of the driver (e.g. for /proc/tty/drivers)
563 * devname Name of the device files (prefix without minor number)
564 */
gigaset_if_initdriver(struct gigaset_driver * drv,const char * procname,const char * devname)565 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
566 const char *devname)
567 {
568 int ret;
569 struct tty_driver *tty;
570
571 drv->have_tty = 0;
572
573 drv->tty = tty = alloc_tty_driver(drv->minors);
574 if (tty == NULL)
575 goto enomem;
576
577 tty->type = TTY_DRIVER_TYPE_SERIAL;
578 tty->subtype = SERIAL_TYPE_NORMAL;
579 tty->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
580
581 tty->driver_name = procname;
582 tty->name = devname;
583 tty->minor_start = drv->minor;
584
585 tty->init_termios = tty_std_termios;
586 tty->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
587 tty_set_operations(tty, &if_ops);
588
589 ret = tty_register_driver(tty);
590 if (ret < 0) {
591 pr_err("error %d registering tty driver\n", ret);
592 goto error;
593 }
594 gig_dbg(DEBUG_IF, "tty driver initialized");
595 drv->have_tty = 1;
596 return;
597
598 enomem:
599 pr_err("out of memory\n");
600 error:
601 if (drv->tty)
602 put_tty_driver(drv->tty);
603 }
604
gigaset_if_freedriver(struct gigaset_driver * drv)605 void gigaset_if_freedriver(struct gigaset_driver *drv)
606 {
607 if (!drv->have_tty)
608 return;
609
610 drv->have_tty = 0;
611 tty_unregister_driver(drv->tty);
612 put_tty_driver(drv->tty);
613 }
614
