1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2008  by Karsten Keil <kkeil@novell.com>
4 */
5
6#include <linux/slab.h>
7#include <linux/types.h>
8#include <linux/stddef.h>
9#include <linux/module.h>
10#include <linux/spinlock.h>
11#include <linux/mISDNif.h>
12#include "core.h"
13
14static u_int debug;
15
16MODULE_AUTHOR("Karsten Keil");
17MODULE_LICENSE("GPL");
18module_param(debug, uint, S_IRUGO | S_IWUSR);
19
20static u64		device_ids;
21#define MAX_DEVICE_ID	63
22
23static LIST_HEAD(Bprotocols);
24static DEFINE_RWLOCK(bp_lock);
25
26static void mISDN_dev_release(struct device *dev)
27{
28	/* nothing to do: the device is part of its parent's data structure */
29}
30
31static ssize_t id_show(struct device *dev,
32		       struct device_attribute *attr, char *buf)
33{
34	struct mISDNdevice *mdev = dev_to_mISDN(dev);
35
36	if (!mdev)
37		return -ENODEV;
38	return sprintf(buf, "%d\n", mdev->id);
39}
40static DEVICE_ATTR_RO(id);
41
42static ssize_t nrbchan_show(struct device *dev,
43			    struct device_attribute *attr, char *buf)
44{
45	struct mISDNdevice *mdev = dev_to_mISDN(dev);
46
47	if (!mdev)
48		return -ENODEV;
49	return sprintf(buf, "%d\n", mdev->nrbchan);
50}
51static DEVICE_ATTR_RO(nrbchan);
52
53static ssize_t d_protocols_show(struct device *dev,
54				struct device_attribute *attr, char *buf)
55{
56	struct mISDNdevice *mdev = dev_to_mISDN(dev);
57
58	if (!mdev)
59		return -ENODEV;
60	return sprintf(buf, "%d\n", mdev->Dprotocols);
61}
62static DEVICE_ATTR_RO(d_protocols);
63
64static ssize_t b_protocols_show(struct device *dev,
65				struct device_attribute *attr, char *buf)
66{
67	struct mISDNdevice *mdev = dev_to_mISDN(dev);
68
69	if (!mdev)
70		return -ENODEV;
71	return sprintf(buf, "%d\n", mdev->Bprotocols | get_all_Bprotocols());
72}
73static DEVICE_ATTR_RO(b_protocols);
74
75static ssize_t protocol_show(struct device *dev,
76			     struct device_attribute *attr, char *buf)
77{
78	struct mISDNdevice *mdev = dev_to_mISDN(dev);
79
80	if (!mdev)
81		return -ENODEV;
82	return sprintf(buf, "%d\n", mdev->D.protocol);
83}
84static DEVICE_ATTR_RO(protocol);
85
86static ssize_t name_show(struct device *dev,
87			 struct device_attribute *attr, char *buf)
88{
89	strcpy(buf, dev_name(dev));
90	return strlen(buf);
91}
92static DEVICE_ATTR_RO(name);
93
94#if 0 /* hangs */
95static ssize_t name_set(struct device *dev, struct device_attribute *attr,
96			const char *buf, size_t count)
97{
98	int err = 0;
99	char *out = kmalloc(count + 1, GFP_KERNEL);
100
101	if (!out)
102		return -ENOMEM;
103
104	memcpy(out, buf, count);
105	if (count && out[count - 1] == '\n')
106		out[--count] = 0;
107	if (count)
108		err = device_rename(dev, out);
109	kfree(out);
110
111	return (err < 0) ? err : count;
112}
113static DEVICE_ATTR_RW(name);
114#endif
115
116static ssize_t channelmap_show(struct device *dev,
117			       struct device_attribute *attr, char *buf)
118{
119	struct mISDNdevice *mdev = dev_to_mISDN(dev);
120	char *bp = buf;
121	int i;
122
123	for (i = 0; i <= mdev->nrbchan; i++)
124		*bp++ = test_channelmap(i, mdev->channelmap) ? '1' : '0';
125
126	return bp - buf;
127}
128static DEVICE_ATTR_RO(channelmap);
129
130static struct attribute *mISDN_attrs[] = {
131	&dev_attr_id.attr,
132	&dev_attr_d_protocols.attr,
133	&dev_attr_b_protocols.attr,
134	&dev_attr_protocol.attr,
135	&dev_attr_channelmap.attr,
136	&dev_attr_nrbchan.attr,
137	&dev_attr_name.attr,
138	NULL,
139};
140ATTRIBUTE_GROUPS(mISDN);
141
142static int mISDN_uevent(const struct device *dev, struct kobj_uevent_env *env)
143{
144	const struct mISDNdevice *mdev = dev_to_mISDN(dev);
145
146	if (!mdev)
147		return 0;
148
149	if (add_uevent_var(env, "nchans=%d", mdev->nrbchan))
150		return -ENOMEM;
151
152	return 0;
153}
154
155static struct class mISDN_class = {
156	.name = "mISDN",
157	.dev_uevent = mISDN_uevent,
158	.dev_groups = mISDN_groups,
159	.dev_release = mISDN_dev_release,
160};
161
162static int
163_get_mdevice(struct device *dev, const void *id)
164{
165	struct mISDNdevice *mdev = dev_to_mISDN(dev);
166
167	if (!mdev)
168		return 0;
169	if (mdev->id != *(const u_int *)id)
170		return 0;
171	return 1;
172}
173
174struct mISDNdevice
175*get_mdevice(u_int id)
176{
177	return dev_to_mISDN(class_find_device(&mISDN_class, NULL, &id,
178					      _get_mdevice));
179}
180
181static int
182_get_mdevice_count(struct device *dev, void *cnt)
183{
184	*(int *)cnt += 1;
185	return 0;
186}
187
188int
189get_mdevice_count(void)
190{
191	int cnt = 0;
192
193	class_for_each_device(&mISDN_class, NULL, &cnt, _get_mdevice_count);
194	return cnt;
195}
196
197static int
198get_free_devid(void)
199{
200	u_int	i;
201
202	for (i = 0; i <= MAX_DEVICE_ID; i++)
203		if (!test_and_set_bit(i, (u_long *)&device_ids))
204			break;
205	if (i > MAX_DEVICE_ID)
206		return -EBUSY;
207	return i;
208}
209
210int
211mISDN_register_device(struct mISDNdevice *dev,
212		      struct device *parent, char *name)
213{
214	int	err;
215
216	err = get_free_devid();
217	if (err < 0)
218		return err;
219	dev->id = err;
220
221	device_initialize(&dev->dev);
222	if (name && name[0])
223		dev_set_name(&dev->dev, "%s", name);
224	else
225		dev_set_name(&dev->dev, "mISDN%d", dev->id);
226	if (debug & DEBUG_CORE)
227		printk(KERN_DEBUG "mISDN_register %s %d\n",
228		       dev_name(&dev->dev), dev->id);
229	dev->dev.class = &mISDN_class;
230
231	err = create_stack(dev);
232	if (err)
233		goto error1;
234
235	dev->dev.platform_data = dev;
236	dev->dev.parent = parent;
237	dev_set_drvdata(&dev->dev, dev);
238
239	err = device_add(&dev->dev);
240	if (err)
241		goto error3;
242	return 0;
243
244error3:
245	delete_stack(dev);
246error1:
247	put_device(&dev->dev);
248	return err;
249
250}
251EXPORT_SYMBOL(mISDN_register_device);
252
253void
254mISDN_unregister_device(struct mISDNdevice *dev) {
255	if (debug & DEBUG_CORE)
256		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
257		       dev_name(&dev->dev), dev->id);
258	/* sysfs_remove_link(&dev->dev.kobj, "device"); */
259	device_del(&dev->dev);
260	dev_set_drvdata(&dev->dev, NULL);
261
262	test_and_clear_bit(dev->id, (u_long *)&device_ids);
263	delete_stack(dev);
264	put_device(&dev->dev);
265}
266EXPORT_SYMBOL(mISDN_unregister_device);
267
268u_int
269get_all_Bprotocols(void)
270{
271	struct Bprotocol	*bp;
272	u_int	m = 0;
273
274	read_lock(&bp_lock);
275	list_for_each_entry(bp, &Bprotocols, list)
276		m |= bp->Bprotocols;
277	read_unlock(&bp_lock);
278	return m;
279}
280
281struct Bprotocol *
282get_Bprotocol4mask(u_int m)
283{
284	struct Bprotocol	*bp;
285
286	read_lock(&bp_lock);
287	list_for_each_entry(bp, &Bprotocols, list)
288		if (bp->Bprotocols & m) {
289			read_unlock(&bp_lock);
290			return bp;
291		}
292	read_unlock(&bp_lock);
293	return NULL;
294}
295
296struct Bprotocol *
297get_Bprotocol4id(u_int id)
298{
299	u_int	m;
300
301	if (id < ISDN_P_B_START || id > 63) {
302		printk(KERN_WARNING "%s id not in range  %d\n",
303		       __func__, id);
304		return NULL;
305	}
306	m = 1 << (id & ISDN_P_B_MASK);
307	return get_Bprotocol4mask(m);
308}
309
310int
311mISDN_register_Bprotocol(struct Bprotocol *bp)
312{
313	u_long			flags;
314	struct Bprotocol	*old;
315
316	if (debug & DEBUG_CORE)
317		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
318		       bp->name, bp->Bprotocols);
319	old = get_Bprotocol4mask(bp->Bprotocols);
320	if (old) {
321		printk(KERN_WARNING
322		       "register duplicate protocol old %s/%x new %s/%x\n",
323		       old->name, old->Bprotocols, bp->name, bp->Bprotocols);
324		return -EBUSY;
325	}
326	write_lock_irqsave(&bp_lock, flags);
327	list_add_tail(&bp->list, &Bprotocols);
328	write_unlock_irqrestore(&bp_lock, flags);
329	return 0;
330}
331EXPORT_SYMBOL(mISDN_register_Bprotocol);
332
333void
334mISDN_unregister_Bprotocol(struct Bprotocol *bp)
335{
336	u_long	flags;
337
338	if (debug & DEBUG_CORE)
339		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
340		       bp->Bprotocols);
341	write_lock_irqsave(&bp_lock, flags);
342	list_del(&bp->list);
343	write_unlock_irqrestore(&bp_lock, flags);
344}
345EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
346
347static const char *msg_no_channel = "<no channel>";
348static const char *msg_no_stack = "<no stack>";
349static const char *msg_no_stackdev = "<no stack device>";
350
351const char *mISDNDevName4ch(struct mISDNchannel *ch)
352{
353	if (!ch)
354		return msg_no_channel;
355	if (!ch->st)
356		return msg_no_stack;
357	if (!ch->st->dev)
358		return msg_no_stackdev;
359	return dev_name(&ch->st->dev->dev);
360};
361EXPORT_SYMBOL(mISDNDevName4ch);
362
363static int
364mISDNInit(void)
365{
366	int	err;
367
368	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
369	       MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
370	mISDN_init_clock(&debug);
371	mISDN_initstack(&debug);
372	err = class_register(&mISDN_class);
373	if (err)
374		goto error1;
375	err = mISDN_inittimer(&debug);
376	if (err)
377		goto error2;
378	err = Isdnl1_Init(&debug);
379	if (err)
380		goto error3;
381	err = Isdnl2_Init(&debug);
382	if (err)
383		goto error4;
384	err = misdn_sock_init(&debug);
385	if (err)
386		goto error5;
387	return 0;
388
389error5:
390	Isdnl2_cleanup();
391error4:
392	Isdnl1_cleanup();
393error3:
394	mISDN_timer_cleanup();
395error2:
396	class_unregister(&mISDN_class);
397error1:
398	return err;
399}
400
401static void mISDN_cleanup(void)
402{
403	misdn_sock_cleanup();
404	Isdnl2_cleanup();
405	Isdnl1_cleanup();
406	mISDN_timer_cleanup();
407	class_unregister(&mISDN_class);
408
409	printk(KERN_DEBUG "mISDNcore unloaded\n");
410}
411
412module_init(mISDNInit);
413module_exit(mISDN_cleanup);
414