1/*
2 * interface to user space for the gigaset driver
3 *
4 * Copyright (c) 2004 by Hansjoerg Lipp <hjlipp@web.de>
5 *
6 * =====================================================================
7 *    This program is free software; you can redistribute it and/or
8 *    modify it under the terms of the GNU General Public License as
9 *    published by the Free Software Foundation; either version 2 of
10 *    the License, or (at your option) any later version.
11 * =====================================================================
12 */
13
14#include "gigaset.h"
15#include <linux/gigaset_dev.h>
16#include <linux/tty.h>
17#include <linux/tty_flip.h>
18
19/*** our ioctls ***/
20
21static int if_lock(struct cardstate *cs, int *arg)
22{
23	int cmd = *arg;
24
25	gig_dbg(DEBUG_IF, "%u: if_lock (%d)", cs->minor_index, cmd);
26
27	if (cmd > 1)
28		return -EINVAL;
29
30	if (cmd < 0) {
31		*arg = atomic_read(&cs->mstate) == MS_LOCKED;
32		return 0;
33	}
34
35	if (!cmd && atomic_read(&cs->mstate) == MS_LOCKED
36	    && cs->connected) {
37		cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
38		cs->ops->baud_rate(cs, B115200);
39		cs->ops->set_line_ctrl(cs, CS8);
40		cs->control_state = TIOCM_DTR|TIOCM_RTS;
41	}
42
43	cs->waiting = 1;
44	if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
45			       NULL, cmd, NULL)) {
46		cs->waiting = 0;
47		return -ENOMEM;
48	}
49
50	gig_dbg(DEBUG_CMD, "scheduling IF_LOCK");
51	gigaset_schedule_event(cs);
52
53	wait_event(cs->waitqueue, !cs->waiting);
54
55	if (cs->cmd_result >= 0) {
56		*arg = cs->cmd_result;
57		return 0;
58	}
59
60	return cs->cmd_result;
61}
62
63static int if_version(struct cardstate *cs, unsigned arg[4])
64{
65	static const unsigned version[4] = GIG_VERSION;
66	static const unsigned compat[4] = GIG_COMPAT;
67	unsigned cmd = arg[0];
68
69	gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
70
71	switch (cmd) {
72	case GIGVER_DRIVER:
73		memcpy(arg, version, sizeof version);
74		return 0;
75	case GIGVER_COMPAT:
76		memcpy(arg, compat, sizeof compat);
77		return 0;
78	case GIGVER_FWBASE:
79		cs->waiting = 1;
80		if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
81				       NULL, 0, arg)) {
82			cs->waiting = 0;
83			return -ENOMEM;
84		}
85
86		gig_dbg(DEBUG_CMD, "scheduling IF_VER");
87		gigaset_schedule_event(cs);
88
89		wait_event(cs->waitqueue, !cs->waiting);
90
91		if (cs->cmd_result >= 0)
92			return 0;
93
94		return cs->cmd_result;
95	default:
96		return -EINVAL;
97	}
98}
99
100static int if_config(struct cardstate *cs, int *arg)
101{
102	gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
103
104	if (*arg != 1)
105		return -EINVAL;
106
107	if (atomic_read(&cs->mstate) != MS_LOCKED)
108		return -EBUSY;
109
110	if (!cs->connected) {
111		err("not connected!");
112		return -ENODEV;
113	}
114
115	*arg = 0;
116	return gigaset_enterconfigmode(cs);
117}
118
119/*** the terminal driver ***/
120/* stolen from usbserial and some other tty drivers */
121
122static int  if_open(struct tty_struct *tty, struct file *filp);
123static void if_close(struct tty_struct *tty, struct file *filp);
124static int  if_ioctl(struct tty_struct *tty, struct file *file,
125		     unsigned int cmd, unsigned long arg);
126static int  if_write_room(struct tty_struct *tty);
127static int  if_chars_in_buffer(struct tty_struct *tty);
128static void if_throttle(struct tty_struct *tty);
129static void if_unthrottle(struct tty_struct *tty);
130static void if_set_termios(struct tty_struct *tty, struct ktermios *old);
131static int  if_tiocmget(struct tty_struct *tty, struct file *file);
132static int  if_tiocmset(struct tty_struct *tty, struct file *file,
133			unsigned int set, unsigned int clear);
134static int  if_write(struct tty_struct *tty,
135		     const unsigned char *buf, int count);
136
137static const struct tty_operations if_ops = {
138	.open =			if_open,
139	.close =		if_close,
140	.ioctl =		if_ioctl,
141	.write =		if_write,
142	.write_room =		if_write_room,
143	.chars_in_buffer =	if_chars_in_buffer,
144	.set_termios =		if_set_termios,
145	.throttle =		if_throttle,
146	.unthrottle =		if_unthrottle,
147	.tiocmget =		if_tiocmget,
148	.tiocmset =		if_tiocmset,
149};
150
151static int if_open(struct tty_struct *tty, struct file *filp)
152{
153	struct cardstate *cs;
154	unsigned long flags;
155
156	gig_dbg(DEBUG_IF, "%d+%d: %s()",
157		tty->driver->minor_start, tty->index, __func__);
158
159	tty->driver_data = NULL;
160
161	cs = gigaset_get_cs_by_tty(tty);
162	if (!cs)
163		return -ENODEV;
164
165	if (mutex_lock_interruptible(&cs->mutex))
166		return -ERESTARTSYS;
167	tty->driver_data = cs;
168
169	++cs->open_count;
170
171	if (cs->open_count == 1) {
172		spin_lock_irqsave(&cs->lock, flags);
173		cs->tty = tty;
174		spin_unlock_irqrestore(&cs->lock, flags);
175		tty->low_latency = 1;
176	}
177
178	mutex_unlock(&cs->mutex);
179	return 0;
180}
181
182static void if_close(struct tty_struct *tty, struct file *filp)
183{
184	struct cardstate *cs;
185	unsigned long flags;
186
187	cs = (struct cardstate *) tty->driver_data;
188	if (!cs) {
189		err("cs==NULL in %s", __func__);
190		return;
191	}
192
193	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
194
195	mutex_lock(&cs->mutex);
196
197	if (!cs->open_count)
198		warn("%s: device not opened", __func__);
199	else {
200		if (!--cs->open_count) {
201			spin_lock_irqsave(&cs->lock, flags);
202			cs->tty = NULL;
203			spin_unlock_irqrestore(&cs->lock, flags);
204		}
205	}
206
207	mutex_unlock(&cs->mutex);
208}
209
210static int if_ioctl(struct tty_struct *tty, struct file *file,
211		    unsigned int cmd, unsigned long arg)
212{
213	struct cardstate *cs;
214	int retval = -ENODEV;
215	int int_arg;
216	unsigned char buf[6];
217	unsigned version[4];
218
219	cs = (struct cardstate *) tty->driver_data;
220	if (!cs) {
221		err("cs==NULL in %s", __func__);
222		return -ENODEV;
223	}
224
225	gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
226
227	if (mutex_lock_interruptible(&cs->mutex))
228		return -ERESTARTSYS;
229
230	if (!cs->open_count)
231		warn("%s: device not opened", __func__);
232	else {
233		retval = 0;
234		switch (cmd) {
235		case GIGASET_REDIR:
236			retval = get_user(int_arg, (int __user *) arg);
237			if (retval >= 0)
238				retval = if_lock(cs, &int_arg);
239			if (retval >= 0)
240				retval = put_user(int_arg, (int __user *) arg);
241			break;
242		case GIGASET_CONFIG:
243			retval = get_user(int_arg, (int __user *) arg);
244			if (retval >= 0)
245				retval = if_config(cs, &int_arg);
246			if (retval >= 0)
247				retval = put_user(int_arg, (int __user *) arg);
248			break;
249		case GIGASET_BRKCHARS:
250			if (!cs->connected) {
251				gig_dbg(DEBUG_ANY,
252				    "can't communicate with unplugged device");
253				retval = -ENODEV;
254				break;
255			}
256			retval = copy_from_user(&buf,
257					(const unsigned char __user *) arg, 6)
258				? -EFAULT : 0;
259			if (retval >= 0) {
260				gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
261						6, (const unsigned char *) arg);
262				retval = cs->ops->brkchars(cs, buf);
263			}
264			break;
265		case GIGASET_VERSION:
266			retval = copy_from_user(version,
267					(unsigned __user *) arg, sizeof version)
268				? -EFAULT : 0;
269			if (retval >= 0)
270				retval = if_version(cs, version);
271			if (retval >= 0)
272				retval = copy_to_user((unsigned __user *) arg,
273						      version, sizeof version)
274					? -EFAULT : 0;
275			break;
276		default:
277			gig_dbg(DEBUG_ANY, "%s: arg not supported - 0x%04x",
278				__func__, cmd);
279			retval = -ENOIOCTLCMD;
280		}
281	}
282
283	mutex_unlock(&cs->mutex);
284
285	return retval;
286}
287
288static int if_tiocmget(struct tty_struct *tty, struct file *file)
289{
290	struct cardstate *cs;
291	int retval;
292
293	cs = (struct cardstate *) tty->driver_data;
294	if (!cs) {
295		err("cs==NULL in %s", __func__);
296		return -ENODEV;
297	}
298
299	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
300
301	if (mutex_lock_interruptible(&cs->mutex))
302		return -ERESTARTSYS;
303
304	retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
305
306	mutex_unlock(&cs->mutex);
307
308	return retval;
309}
310
311static int if_tiocmset(struct tty_struct *tty, struct file *file,
312		       unsigned int set, unsigned int clear)
313{
314	struct cardstate *cs;
315	int retval;
316	unsigned mc;
317
318	cs = (struct cardstate *) tty->driver_data;
319	if (!cs) {
320		err("cs==NULL in %s", __func__);
321		return -ENODEV;
322	}
323
324	gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
325		cs->minor_index, __func__, set, clear);
326
327	if (mutex_lock_interruptible(&cs->mutex))
328		return -ERESTARTSYS;
329
330	if (!cs->connected) {
331		gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
332		retval = -ENODEV;
333	} else {
334		mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
335		retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
336		cs->control_state = mc;
337	}
338
339	mutex_unlock(&cs->mutex);
340
341	return retval;
342}
343
344static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
345{
346	struct cardstate *cs;
347	int retval = -ENODEV;
348
349	cs = (struct cardstate *) tty->driver_data;
350	if (!cs) {
351		err("cs==NULL in %s", __func__);
352		return -ENODEV;
353	}
354
355	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
356
357	if (mutex_lock_interruptible(&cs->mutex))
358		return -ERESTARTSYS;
359
360	if (!cs->open_count)
361		warn("%s: device not opened", __func__);
362	else if (atomic_read(&cs->mstate) != MS_LOCKED) {
363		warn("can't write to unlocked device");
364		retval = -EBUSY;
365	} else if (!cs->connected) {
366		gig_dbg(DEBUG_ANY, "can't write to unplugged device");
367		retval = -EBUSY;
368	} else {
369		retval = cs->ops->write_cmd(cs, buf, count,
370					    &cs->if_wake_tasklet);
371	}
372
373	mutex_unlock(&cs->mutex);
374
375	return retval;
376}
377
378static int if_write_room(struct tty_struct *tty)
379{
380	struct cardstate *cs;
381	int retval = -ENODEV;
382
383	cs = (struct cardstate *) tty->driver_data;
384	if (!cs) {
385		err("cs==NULL in %s", __func__);
386		return -ENODEV;
387	}
388
389	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
390
391	if (mutex_lock_interruptible(&cs->mutex))
392		return -ERESTARTSYS;
393
394	if (!cs->open_count)
395		warn("%s: device not opened", __func__);
396	else if (atomic_read(&cs->mstate) != MS_LOCKED) {
397		warn("can't write to unlocked device");
398		retval = -EBUSY;
399	} else if (!cs->connected) {
400		gig_dbg(DEBUG_ANY, "can't write to unplugged device");
401		retval = -EBUSY;
402	} else
403		retval = cs->ops->write_room(cs);
404
405	mutex_unlock(&cs->mutex);
406
407	return retval;
408}
409
410static int if_chars_in_buffer(struct tty_struct *tty)
411{
412	struct cardstate *cs;
413	int retval = -ENODEV;
414
415	cs = (struct cardstate *) tty->driver_data;
416	if (!cs) {
417		err("cs==NULL in %s", __func__);
418		return -ENODEV;
419	}
420
421	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
422
423	if (mutex_lock_interruptible(&cs->mutex))
424		return -ERESTARTSYS;
425
426	if (!cs->open_count)
427		warn("%s: device not opened", __func__);
428	else if (atomic_read(&cs->mstate) != MS_LOCKED) {
429		warn("can't write to unlocked device");
430		retval = -EBUSY;
431	} else if (!cs->connected) {
432		gig_dbg(DEBUG_ANY, "can't write to unplugged device");
433		retval = -EBUSY;
434	} else
435		retval = cs->ops->chars_in_buffer(cs);
436
437	mutex_unlock(&cs->mutex);
438
439	return retval;
440}
441
442static void if_throttle(struct tty_struct *tty)
443{
444	struct cardstate *cs;
445
446	cs = (struct cardstate *) tty->driver_data;
447	if (!cs) {
448		err("cs==NULL in %s", __func__);
449		return;
450	}
451
452	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
453
454	mutex_lock(&cs->mutex);
455
456	if (!cs->open_count)
457		warn("%s: device not opened", __func__);
458	else {
459	}
460
461	mutex_unlock(&cs->mutex);
462}
463
464static void if_unthrottle(struct tty_struct *tty)
465{
466	struct cardstate *cs;
467
468	cs = (struct cardstate *) tty->driver_data;
469	if (!cs) {
470		err("cs==NULL in %s", __func__);
471		return;
472	}
473
474	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
475
476	mutex_lock(&cs->mutex);
477
478	if (!cs->open_count)
479		warn("%s: device not opened", __func__);
480	else {
481	}
482
483	mutex_unlock(&cs->mutex);
484}
485
486static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
487{
488	struct cardstate *cs;
489	unsigned int iflag;
490	unsigned int cflag;
491	unsigned int old_cflag;
492	unsigned int control_state, new_state;
493
494	cs = (struct cardstate *) tty->driver_data;
495	if (!cs) {
496		err("cs==NULL in %s", __func__);
497		return;
498	}
499
500	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
501
502	mutex_lock(&cs->mutex);
503
504	if (!cs->open_count) {
505		warn("%s: device not opened", __func__);
506		goto out;
507	}
508
509	if (!cs->connected) {
510		gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
511		goto out;
512	}
513
514	// stolen from mct_u232.c
515	iflag = tty->termios->c_iflag;
516	cflag = tty->termios->c_cflag;
517	old_cflag = old ? old->c_cflag : cflag;
518	gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
519		cs->minor_index, iflag, cflag, old_cflag);
520
521	/* get a local copy of the current port settings */
522	control_state = cs->control_state;
523
524	/*
525	 * Update baud rate.
526	 * Do not attempt to cache old rates and skip settings,
527	 * disconnects screw such tricks up completely.
528	 * Premature optimization is the root of all evil.
529	 */
530
531	/* reassert DTR and (maybe) RTS on transition from B0 */
532	if ((old_cflag & CBAUD) == B0) {
533		new_state = control_state | TIOCM_DTR;
534		/* don't set RTS if using hardware flow control */
535		if (!(old_cflag & CRTSCTS))
536			new_state |= TIOCM_RTS;
537		gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
538			cs->minor_index,
539			(new_state & TIOCM_RTS) ? " only" : "/RTS");
540		cs->ops->set_modem_ctrl(cs, control_state, new_state);
541		control_state = new_state;
542	}
543
544	cs->ops->baud_rate(cs, cflag & CBAUD);
545
546	if ((cflag & CBAUD) == B0) {
547		/* Drop RTS and DTR */
548		gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
549		new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
550		cs->ops->set_modem_ctrl(cs, control_state, new_state);
551		control_state = new_state;
552	}
553
554	/*
555	 * Update line control register (LCR)
556	 */
557
558	cs->ops->set_line_ctrl(cs, cflag);
559
560
561	/* save off the modified port settings */
562	cs->control_state = control_state;
563
564out:
565	mutex_unlock(&cs->mutex);
566}
567
568
569/* wakeup tasklet for the write operation */
570static void if_wake(unsigned long data)
571{
572	struct cardstate *cs = (struct cardstate *) data;
573
574	if (cs->tty)
575		tty_wakeup(cs->tty);
576}
577
578/*** interface to common ***/
579
580void gigaset_if_init(struct cardstate *cs)
581{
582	struct gigaset_driver *drv;
583
584	drv = cs->driver;
585	if (!drv->have_tty)
586		return;
587
588	tasklet_init(&cs->if_wake_tasklet, &if_wake, (unsigned long) cs);
589
590	mutex_lock(&cs->mutex);
591	cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
592
593	if (!IS_ERR(cs->tty_dev))
594		dev_set_drvdata(cs->tty_dev, cs);
595	else {
596		warn("could not register device to the tty subsystem");
597		cs->tty_dev = NULL;
598	}
599	mutex_unlock(&cs->mutex);
600}
601
602void gigaset_if_free(struct cardstate *cs)
603{
604	struct gigaset_driver *drv;
605
606	drv = cs->driver;
607	if (!drv->have_tty)
608		return;
609
610	tasklet_disable(&cs->if_wake_tasklet);
611	tasklet_kill(&cs->if_wake_tasklet);
612	cs->tty_dev = NULL;
613	tty_unregister_device(drv->tty, cs->minor_index);
614}
615
616void gigaset_if_receive(struct cardstate *cs,
617			unsigned char *buffer, size_t len)
618{
619	unsigned long flags;
620	struct tty_struct *tty;
621
622	spin_lock_irqsave(&cs->lock, flags);
623	if ((tty = cs->tty) == NULL)
624		gig_dbg(DEBUG_ANY, "receive on closed device");
625	else {
626		tty_buffer_request_room(tty, len);
627		tty_insert_flip_string(tty, buffer, len);
628		tty_flip_buffer_push(tty);
629	}
630	spin_unlock_irqrestore(&cs->lock, flags);
631}
632EXPORT_SYMBOL_GPL(gigaset_if_receive);
633
634/* gigaset_if_initdriver
635 * Initialize tty interface.
636 * parameters:
637 *	drv		Driver
638 *	procname	Name of the driver (e.g. for /proc/tty/drivers)
639 *	devname		Name of the device files (prefix without minor number)
640 */
641void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
642			   const char *devname)
643{
644	unsigned minors = drv->minors;
645	int ret;
646	struct tty_driver *tty;
647
648	drv->have_tty = 0;
649
650	if ((drv->tty = alloc_tty_driver(minors)) == NULL)
651		goto enomem;
652	tty = drv->tty;
653
654	tty->magic =		TTY_DRIVER_MAGIC,
655	tty->major =		GIG_MAJOR,
656	tty->type =		TTY_DRIVER_TYPE_SERIAL,
657	tty->subtype =		SERIAL_TYPE_NORMAL,
658	tty->flags =		TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
659
660	tty->driver_name =	procname;
661	tty->name =		devname;
662	tty->minor_start =	drv->minor;
663	tty->num =		drv->minors;
664
665	tty->owner =		THIS_MODULE;
666
667	tty->init_termios          = tty_std_termios;
668	tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
669	tty_set_operations(tty, &if_ops);
670
671	ret = tty_register_driver(tty);
672	if (ret < 0) {
673		warn("failed to register tty driver (error %d)", ret);
674		goto error;
675	}
676	gig_dbg(DEBUG_IF, "tty driver initialized");
677	drv->have_tty = 1;
678	return;
679
680enomem:
681	warn("could not allocate tty structures");
682error:
683	if (drv->tty)
684		put_tty_driver(drv->tty);
685}
686
687void gigaset_if_freedriver(struct gigaset_driver *drv)
688{
689	if (!drv->have_tty)
690		return;
691
692	drv->have_tty = 0;
693	tty_unregister_driver(drv->tty);
694	put_tty_driver(drv->tty);
695}
696