interface.c revision 48a7466f4dd0104d87a6d8dd0f25027be89c8453
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_flip.h>
17#include <linux/module.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 = cs->mstate == MS_LOCKED;
32		return 0;
33	}
34
35	if (!cmd && cs->mstate == MS_LOCKED && cs->connected) {
36		cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
37		cs->ops->baud_rate(cs, B115200);
38		cs->ops->set_line_ctrl(cs, CS8);
39		cs->control_state = TIOCM_DTR|TIOCM_RTS;
40	}
41
42	cs->waiting = 1;
43	if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
44			       NULL, cmd, NULL)) {
45		cs->waiting = 0;
46		return -ENOMEM;
47	}
48	gigaset_schedule_event(cs);
49
50	wait_event(cs->waitqueue, !cs->waiting);
51
52	if (cs->cmd_result >= 0) {
53		*arg = cs->cmd_result;
54		return 0;
55	}
56
57	return cs->cmd_result;
58}
59
60static int if_version(struct cardstate *cs, unsigned arg[4])
61{
62	static const unsigned version[4] = GIG_VERSION;
63	static const unsigned compat[4] = GIG_COMPAT;
64	unsigned cmd = arg[0];
65
66	gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
67
68	switch (cmd) {
69	case GIGVER_DRIVER:
70		memcpy(arg, version, sizeof version);
71		return 0;
72	case GIGVER_COMPAT:
73		memcpy(arg, compat, sizeof compat);
74		return 0;
75	case GIGVER_FWBASE:
76		cs->waiting = 1;
77		if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
78				       NULL, 0, arg)) {
79			cs->waiting = 0;
80			return -ENOMEM;
81		}
82		gigaset_schedule_event(cs);
83
84		wait_event(cs->waitqueue, !cs->waiting);
85
86		if (cs->cmd_result >= 0)
87			return 0;
88
89		return cs->cmd_result;
90	default:
91		return -EINVAL;
92	}
93}
94
95static int if_config(struct cardstate *cs, int *arg)
96{
97	gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
98
99	if (*arg != 1)
100		return -EINVAL;
101
102	if (cs->mstate != MS_LOCKED)
103		return -EBUSY;
104
105	if (!cs->connected) {
106		pr_err("%s: not connected\n", __func__);
107		return -ENODEV;
108	}
109
110	*arg = 0;
111	return gigaset_enterconfigmode(cs);
112}
113
114/*** the terminal driver ***/
115/* stolen from usbserial and some other tty drivers */
116
117static int  if_open(struct tty_struct *tty, struct file *filp);
118static void if_close(struct tty_struct *tty, struct file *filp);
119static int  if_ioctl(struct tty_struct *tty,
120		     unsigned int cmd, unsigned long arg);
121static int  if_write_room(struct tty_struct *tty);
122static int  if_chars_in_buffer(struct tty_struct *tty);
123static void if_throttle(struct tty_struct *tty);
124static void if_unthrottle(struct tty_struct *tty);
125static void if_set_termios(struct tty_struct *tty, struct ktermios *old);
126static int  if_tiocmget(struct tty_struct *tty);
127static int  if_tiocmset(struct tty_struct *tty,
128			unsigned int set, unsigned int clear);
129static int  if_write(struct tty_struct *tty,
130		     const unsigned char *buf, int count);
131
132static const struct tty_operations if_ops = {
133	.open =			if_open,
134	.close =		if_close,
135	.ioctl =		if_ioctl,
136	.write =		if_write,
137	.write_room =		if_write_room,
138	.chars_in_buffer =	if_chars_in_buffer,
139	.set_termios =		if_set_termios,
140	.throttle =		if_throttle,
141	.unthrottle =		if_unthrottle,
142	.tiocmget =		if_tiocmget,
143	.tiocmset =		if_tiocmset,
144};
145
146static int if_open(struct tty_struct *tty, struct file *filp)
147{
148	struct cardstate *cs;
149
150	gig_dbg(DEBUG_IF, "%d+%d: %s()",
151		tty->driver->minor_start, tty->index, __func__);
152
153	cs = gigaset_get_cs_by_tty(tty);
154	if (!cs || !try_module_get(cs->driver->owner))
155		return -ENODEV;
156
157	if (mutex_lock_interruptible(&cs->mutex)) {
158		module_put(cs->driver->owner);
159		return -ERESTARTSYS;
160	}
161	tty->driver_data = cs;
162
163	++cs->port.count;
164
165	if (cs->port.count == 1) {
166		tty_port_tty_set(&cs->port, tty);
167		tty->low_latency = 1;
168	}
169
170	mutex_unlock(&cs->mutex);
171	return 0;
172}
173
174static void if_close(struct tty_struct *tty, struct file *filp)
175{
176	struct cardstate *cs = tty->driver_data;
177
178	if (!cs) { /* happens if we didn't find cs in open */
179		printk(KERN_DEBUG "%s: no cardstate\n", __func__);
180		return;
181	}
182
183	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
184
185	mutex_lock(&cs->mutex);
186
187	if (!cs->connected)
188		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
189	else if (!cs->port.count)
190		dev_warn(cs->dev, "%s: device not opened\n", __func__);
191	else if (!--cs->port.count)
192		tty_port_tty_set(&cs->port, NULL);
193
194	mutex_unlock(&cs->mutex);
195
196	module_put(cs->driver->owner);
197}
198
199static int if_ioctl(struct tty_struct *tty,
200		    unsigned int cmd, unsigned long arg)
201{
202	struct cardstate *cs = tty->driver_data;
203	int retval = -ENODEV;
204	int int_arg;
205	unsigned char buf[6];
206	unsigned version[4];
207
208	gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
209
210	if (mutex_lock_interruptible(&cs->mutex))
211		return -ERESTARTSYS;
212
213	if (!cs->connected) {
214		gig_dbg(DEBUG_IF, "not connected");
215		retval = -ENODEV;
216	} else {
217		retval = 0;
218		switch (cmd) {
219		case GIGASET_REDIR:
220			retval = get_user(int_arg, (int __user *) arg);
221			if (retval >= 0)
222				retval = if_lock(cs, &int_arg);
223			if (retval >= 0)
224				retval = put_user(int_arg, (int __user *) arg);
225			break;
226		case GIGASET_CONFIG:
227			retval = get_user(int_arg, (int __user *) arg);
228			if (retval >= 0)
229				retval = if_config(cs, &int_arg);
230			if (retval >= 0)
231				retval = put_user(int_arg, (int __user *) arg);
232			break;
233		case GIGASET_BRKCHARS:
234			retval = copy_from_user(&buf,
235					(const unsigned char __user *) arg, 6)
236				? -EFAULT : 0;
237			if (retval >= 0) {
238				gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
239						6, (const unsigned char *) arg);
240				retval = cs->ops->brkchars(cs, buf);
241			}
242			break;
243		case GIGASET_VERSION:
244			retval = copy_from_user(version,
245					(unsigned __user *) arg, sizeof version)
246				? -EFAULT : 0;
247			if (retval >= 0)
248				retval = if_version(cs, version);
249			if (retval >= 0)
250				retval = copy_to_user((unsigned __user *) arg,
251						      version, sizeof version)
252					? -EFAULT : 0;
253			break;
254		default:
255			gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
256				__func__, cmd);
257			retval = -ENOIOCTLCMD;
258		}
259	}
260
261	mutex_unlock(&cs->mutex);
262
263	return retval;
264}
265
266static int if_tiocmget(struct tty_struct *tty)
267{
268	struct cardstate *cs = tty->driver_data;
269	int retval;
270
271	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
272
273	if (mutex_lock_interruptible(&cs->mutex))
274		return -ERESTARTSYS;
275
276	retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
277
278	mutex_unlock(&cs->mutex);
279
280	return retval;
281}
282
283static int if_tiocmset(struct tty_struct *tty,
284		       unsigned int set, unsigned int clear)
285{
286	struct cardstate *cs = tty->driver_data;
287	int retval;
288	unsigned mc;
289
290	gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
291		cs->minor_index, __func__, set, clear);
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	} else {
300		mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
301		retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
302		cs->control_state = mc;
303	}
304
305	mutex_unlock(&cs->mutex);
306
307	return retval;
308}
309
310static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
311{
312	struct cardstate *cs = tty->driver_data;
313	struct cmdbuf_t *cb;
314	int retval;
315
316	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
317
318	if (mutex_lock_interruptible(&cs->mutex))
319		return -ERESTARTSYS;
320
321	if (!cs->connected) {
322		gig_dbg(DEBUG_IF, "not connected");
323		retval = -ENODEV;
324		goto done;
325	}
326	if (cs->mstate != MS_LOCKED) {
327		dev_warn(cs->dev, "can't write to unlocked device\n");
328		retval = -EBUSY;
329		goto done;
330	}
331	if (count <= 0) {
332		/* nothing to do */
333		retval = 0;
334		goto done;
335	}
336
337	cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
338	if (!cb) {
339		dev_err(cs->dev, "%s: out of memory\n", __func__);
340		retval = -ENOMEM;
341		goto done;
342	}
343
344	memcpy(cb->buf, buf, count);
345	cb->len = count;
346	cb->offset = 0;
347	cb->next = NULL;
348	cb->wake_tasklet = &cs->if_wake_tasklet;
349	retval = cs->ops->write_cmd(cs, cb);
350done:
351	mutex_unlock(&cs->mutex);
352	return retval;
353}
354
355static int if_write_room(struct tty_struct *tty)
356{
357	struct cardstate *cs = tty->driver_data;
358	int retval = -ENODEV;
359
360	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
361
362	if (mutex_lock_interruptible(&cs->mutex))
363		return -ERESTARTSYS;
364
365	if (!cs->connected) {
366		gig_dbg(DEBUG_IF, "not connected");
367		retval = -ENODEV;
368	} else if (cs->mstate != MS_LOCKED) {
369		dev_warn(cs->dev, "can't write to unlocked device\n");
370		retval = -EBUSY;
371	} else
372		retval = cs->ops->write_room(cs);
373
374	mutex_unlock(&cs->mutex);
375
376	return retval;
377}
378
379static int if_chars_in_buffer(struct tty_struct *tty)
380{
381	struct cardstate *cs = tty->driver_data;
382	int retval = 0;
383
384	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
385
386	mutex_lock(&cs->mutex);
387
388	if (!cs->connected)
389		gig_dbg(DEBUG_IF, "not connected");
390	else if (cs->mstate != MS_LOCKED)
391		dev_warn(cs->dev, "can't write to unlocked device\n");
392	else
393		retval = cs->ops->chars_in_buffer(cs);
394
395	mutex_unlock(&cs->mutex);
396
397	return retval;
398}
399
400static void if_throttle(struct tty_struct *tty)
401{
402	struct cardstate *cs = tty->driver_data;
403
404	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
405
406	mutex_lock(&cs->mutex);
407
408	if (!cs->connected)
409		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
410	else
411		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
412
413	mutex_unlock(&cs->mutex);
414}
415
416static void if_unthrottle(struct tty_struct *tty)
417{
418	struct cardstate *cs = tty->driver_data;
419
420	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
421
422	mutex_lock(&cs->mutex);
423
424	if (!cs->connected)
425		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
426	else
427		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
428
429	mutex_unlock(&cs->mutex);
430}
431
432static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
433{
434	struct cardstate *cs = tty->driver_data;
435	unsigned int iflag;
436	unsigned int cflag;
437	unsigned int old_cflag;
438	unsigned int control_state, new_state;
439
440	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
441
442	mutex_lock(&cs->mutex);
443
444	if (!cs->connected) {
445		gig_dbg(DEBUG_IF, "not connected");
446		goto out;
447	}
448
449	iflag = tty->termios->c_iflag;
450	cflag = tty->termios->c_cflag;
451	old_cflag = old ? old->c_cflag : cflag;
452	gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
453		cs->minor_index, iflag, cflag, old_cflag);
454
455	/* get a local copy of the current port settings */
456	control_state = cs->control_state;
457
458	/*
459	 * Update baud rate.
460	 * Do not attempt to cache old rates and skip settings,
461	 * disconnects screw such tricks up completely.
462	 * Premature optimization is the root of all evil.
463	 */
464
465	/* reassert DTR and (maybe) RTS on transition from B0 */
466	if ((old_cflag & CBAUD) == B0) {
467		new_state = control_state | TIOCM_DTR;
468		/* don't set RTS if using hardware flow control */
469		if (!(old_cflag & CRTSCTS))
470			new_state |= TIOCM_RTS;
471		gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
472			cs->minor_index,
473			(new_state & TIOCM_RTS) ? " only" : "/RTS");
474		cs->ops->set_modem_ctrl(cs, control_state, new_state);
475		control_state = new_state;
476	}
477
478	cs->ops->baud_rate(cs, cflag & CBAUD);
479
480	if ((cflag & CBAUD) == B0) {
481		/* Drop RTS and DTR */
482		gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
483		new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
484		cs->ops->set_modem_ctrl(cs, control_state, new_state);
485		control_state = new_state;
486	}
487
488	/*
489	 * Update line control register (LCR)
490	 */
491
492	cs->ops->set_line_ctrl(cs, cflag);
493
494	/* save off the modified port settings */
495	cs->control_state = control_state;
496
497out:
498	mutex_unlock(&cs->mutex);
499}
500
501
502/* wakeup tasklet for the write operation */
503static void if_wake(unsigned long data)
504{
505	struct cardstate *cs = (struct cardstate *)data;
506	struct tty_struct *tty = tty_port_tty_get(&cs->port);
507
508	if (tty) {
509		tty_wakeup(tty);
510		tty_kref_put(tty);
511	}
512}
513
514/*** interface to common ***/
515
516void gigaset_if_init(struct cardstate *cs)
517{
518	struct gigaset_driver *drv;
519
520	drv = cs->driver;
521	if (!drv->have_tty)
522		return;
523
524	tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
525
526	mutex_lock(&cs->mutex);
527	cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
528
529	if (!IS_ERR(cs->tty_dev))
530		dev_set_drvdata(cs->tty_dev, cs);
531	else {
532		pr_warning("could not register device to the tty subsystem\n");
533		cs->tty_dev = NULL;
534	}
535	mutex_unlock(&cs->mutex);
536}
537
538void gigaset_if_free(struct cardstate *cs)
539{
540	struct gigaset_driver *drv;
541
542	drv = cs->driver;
543	if (!drv->have_tty)
544		return;
545
546	tasklet_disable(&cs->if_wake_tasklet);
547	tasklet_kill(&cs->if_wake_tasklet);
548	cs->tty_dev = NULL;
549	tty_unregister_device(drv->tty, cs->minor_index);
550}
551
552/**
553 * gigaset_if_receive() - pass a received block of data to the tty device
554 * @cs:		device descriptor structure.
555 * @buffer:	received data.
556 * @len:	number of bytes received.
557 *
558 * Called by asyncdata/isocdata if a block of data received from the
559 * device must be sent to userspace through the ttyG* device.
560 */
561void gigaset_if_receive(struct cardstate *cs,
562			unsigned char *buffer, size_t len)
563{
564	struct tty_struct *tty = tty_port_tty_get(&cs->port);
565
566	if (tty == NULL) {
567		gig_dbg(DEBUG_IF, "receive on closed device");
568		return;
569	}
570
571	tty_insert_flip_string(tty, buffer, len);
572	tty_flip_buffer_push(tty);
573	tty_kref_put(tty);
574}
575EXPORT_SYMBOL_GPL(gigaset_if_receive);
576
577/* gigaset_if_initdriver
578 * Initialize tty interface.
579 * parameters:
580 *	drv		Driver
581 *	procname	Name of the driver (e.g. for /proc/tty/drivers)
582 *	devname		Name of the device files (prefix without minor number)
583 */
584void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
585			   const char *devname)
586{
587	int ret;
588	struct tty_driver *tty;
589
590	drv->have_tty = 0;
591
592	drv->tty = tty = alloc_tty_driver(drv->minors);
593	if (tty == NULL)
594		goto enomem;
595
596	tty->type =		TTY_DRIVER_TYPE_SERIAL,
597	tty->subtype =		SERIAL_TYPE_NORMAL,
598	tty->flags =		TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
599
600	tty->driver_name =	procname;
601	tty->name =		devname;
602	tty->minor_start =	drv->minor;
603
604	tty->init_termios          = tty_std_termios;
605	tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
606	tty_set_operations(tty, &if_ops);
607
608	ret = tty_register_driver(tty);
609	if (ret < 0) {
610		pr_err("error %d registering tty driver\n", ret);
611		goto error;
612	}
613	gig_dbg(DEBUG_IF, "tty driver initialized");
614	drv->have_tty = 1;
615	return;
616
617enomem:
618	pr_err("out of memory\n");
619error:
620	if (drv->tty)
621		put_tty_driver(drv->tty);
622}
623
624void gigaset_if_freedriver(struct gigaset_driver *drv)
625{
626	if (!drv->have_tty)
627		return;
628
629	drv->have_tty = 0;
630	tty_unregister_driver(drv->tty);
631	put_tty_driver(drv->tty);
632}
633