xref: /linux/drivers/isdn/mISDN/core.c (revision f68f2ff91512c199ec24883001245912afc17873)
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 
14 static u_int debug;
15 
16 MODULE_AUTHOR("Karsten Keil");
17 MODULE_LICENSE("GPL");
18 module_param(debug, uint, S_IRUGO | S_IWUSR);
19 
20 static u64		device_ids;
21 #define MAX_DEVICE_ID	63
22 
23 static LIST_HEAD(Bprotocols);
24 static DEFINE_RWLOCK(bp_lock);
25 
26 static void mISDN_dev_release(struct device *dev)
27 {
28 	/* nothing to do: the device is part of its parent's data structure */
29 }
30 
31 static 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 }
40 static DEVICE_ATTR_RO(id);
41 
42 static 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 }
51 static DEVICE_ATTR_RO(nrbchan);
52 
53 static 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 }
62 static DEVICE_ATTR_RO(d_protocols);
63 
64 static 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 }
73 static DEVICE_ATTR_RO(b_protocols);
74 
75 static 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 }
84 static DEVICE_ATTR_RO(protocol);
85 
86 static 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 }
92 static DEVICE_ATTR_RO(name);
93 
94 #if 0 /* hangs */
95 static 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 }
113 static DEVICE_ATTR_RW(name);
114 #endif
115 
116 static 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 }
128 static DEVICE_ATTR_RO(channelmap);
129 
130 static 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 };
140 ATTRIBUTE_GROUPS(mISDN);
141 
142 static int mISDN_uevent(struct device *dev, struct kobj_uevent_env *env)
143 {
144 	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 
155 static void mISDN_class_release(struct class *cls)
156 {
157 	/* do nothing, it's static */
158 }
159 
160 static struct class mISDN_class = {
161 	.name = "mISDN",
162 	.owner = THIS_MODULE,
163 	.dev_uevent = mISDN_uevent,
164 	.dev_groups = mISDN_groups,
165 	.dev_release = mISDN_dev_release,
166 	.class_release = mISDN_class_release,
167 };
168 
169 static int
170 _get_mdevice(struct device *dev, const void *id)
171 {
172 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
173 
174 	if (!mdev)
175 		return 0;
176 	if (mdev->id != *(const u_int *)id)
177 		return 0;
178 	return 1;
179 }
180 
181 struct mISDNdevice
182 *get_mdevice(u_int id)
183 {
184 	return dev_to_mISDN(class_find_device(&mISDN_class, NULL, &id,
185 					      _get_mdevice));
186 }
187 
188 static int
189 _get_mdevice_count(struct device *dev, void *cnt)
190 {
191 	*(int *)cnt += 1;
192 	return 0;
193 }
194 
195 int
196 get_mdevice_count(void)
197 {
198 	int cnt = 0;
199 
200 	class_for_each_device(&mISDN_class, NULL, &cnt, _get_mdevice_count);
201 	return cnt;
202 }
203 
204 static int
205 get_free_devid(void)
206 {
207 	u_int	i;
208 
209 	for (i = 0; i <= MAX_DEVICE_ID; i++)
210 		if (!test_and_set_bit(i, (u_long *)&device_ids))
211 			break;
212 	if (i > MAX_DEVICE_ID)
213 		return -EBUSY;
214 	return i;
215 }
216 
217 int
218 mISDN_register_device(struct mISDNdevice *dev,
219 		      struct device *parent, char *name)
220 {
221 	int	err;
222 
223 	err = get_free_devid();
224 	if (err < 0)
225 		goto error1;
226 	dev->id = err;
227 
228 	device_initialize(&dev->dev);
229 	if (name && name[0])
230 		dev_set_name(&dev->dev, "%s", name);
231 	else
232 		dev_set_name(&dev->dev, "mISDN%d", dev->id);
233 	if (debug & DEBUG_CORE)
234 		printk(KERN_DEBUG "mISDN_register %s %d\n",
235 		       dev_name(&dev->dev), dev->id);
236 	err = create_stack(dev);
237 	if (err)
238 		goto error1;
239 
240 	dev->dev.class = &mISDN_class;
241 	dev->dev.platform_data = dev;
242 	dev->dev.parent = parent;
243 	dev_set_drvdata(&dev->dev, dev);
244 
245 	err = device_add(&dev->dev);
246 	if (err)
247 		goto error3;
248 	return 0;
249 
250 error3:
251 	delete_stack(dev);
252 	return err;
253 error1:
254 	return err;
255 
256 }
257 EXPORT_SYMBOL(mISDN_register_device);
258 
259 void
260 mISDN_unregister_device(struct mISDNdevice *dev) {
261 	if (debug & DEBUG_CORE)
262 		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
263 		       dev_name(&dev->dev), dev->id);
264 	/* sysfs_remove_link(&dev->dev.kobj, "device"); */
265 	device_del(&dev->dev);
266 	dev_set_drvdata(&dev->dev, NULL);
267 
268 	test_and_clear_bit(dev->id, (u_long *)&device_ids);
269 	delete_stack(dev);
270 	put_device(&dev->dev);
271 }
272 EXPORT_SYMBOL(mISDN_unregister_device);
273 
274 u_int
275 get_all_Bprotocols(void)
276 {
277 	struct Bprotocol	*bp;
278 	u_int	m = 0;
279 
280 	read_lock(&bp_lock);
281 	list_for_each_entry(bp, &Bprotocols, list)
282 		m |= bp->Bprotocols;
283 	read_unlock(&bp_lock);
284 	return m;
285 }
286 
287 struct Bprotocol *
288 get_Bprotocol4mask(u_int m)
289 {
290 	struct Bprotocol	*bp;
291 
292 	read_lock(&bp_lock);
293 	list_for_each_entry(bp, &Bprotocols, list)
294 		if (bp->Bprotocols & m) {
295 			read_unlock(&bp_lock);
296 			return bp;
297 		}
298 	read_unlock(&bp_lock);
299 	return NULL;
300 }
301 
302 struct Bprotocol *
303 get_Bprotocol4id(u_int id)
304 {
305 	u_int	m;
306 
307 	if (id < ISDN_P_B_START || id > 63) {
308 		printk(KERN_WARNING "%s id not in range  %d\n",
309 		       __func__, id);
310 		return NULL;
311 	}
312 	m = 1 << (id & ISDN_P_B_MASK);
313 	return get_Bprotocol4mask(m);
314 }
315 
316 int
317 mISDN_register_Bprotocol(struct Bprotocol *bp)
318 {
319 	u_long			flags;
320 	struct Bprotocol	*old;
321 
322 	if (debug & DEBUG_CORE)
323 		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
324 		       bp->name, bp->Bprotocols);
325 	old = get_Bprotocol4mask(bp->Bprotocols);
326 	if (old) {
327 		printk(KERN_WARNING
328 		       "register duplicate protocol old %s/%x new %s/%x\n",
329 		       old->name, old->Bprotocols, bp->name, bp->Bprotocols);
330 		return -EBUSY;
331 	}
332 	write_lock_irqsave(&bp_lock, flags);
333 	list_add_tail(&bp->list, &Bprotocols);
334 	write_unlock_irqrestore(&bp_lock, flags);
335 	return 0;
336 }
337 EXPORT_SYMBOL(mISDN_register_Bprotocol);
338 
339 void
340 mISDN_unregister_Bprotocol(struct Bprotocol *bp)
341 {
342 	u_long	flags;
343 
344 	if (debug & DEBUG_CORE)
345 		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
346 		       bp->Bprotocols);
347 	write_lock_irqsave(&bp_lock, flags);
348 	list_del(&bp->list);
349 	write_unlock_irqrestore(&bp_lock, flags);
350 }
351 EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
352 
353 static const char *msg_no_channel = "<no channel>";
354 static const char *msg_no_stack = "<no stack>";
355 static const char *msg_no_stackdev = "<no stack device>";
356 
357 const char *mISDNDevName4ch(struct mISDNchannel *ch)
358 {
359 	if (!ch)
360 		return msg_no_channel;
361 	if (!ch->st)
362 		return msg_no_stack;
363 	if (!ch->st->dev)
364 		return msg_no_stackdev;
365 	return dev_name(&ch->st->dev->dev);
366 };
367 EXPORT_SYMBOL(mISDNDevName4ch);
368 
369 static int
370 mISDNInit(void)
371 {
372 	int	err;
373 
374 	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
375 	       MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
376 	mISDN_init_clock(&debug);
377 	mISDN_initstack(&debug);
378 	err = class_register(&mISDN_class);
379 	if (err)
380 		goto error1;
381 	err = mISDN_inittimer(&debug);
382 	if (err)
383 		goto error2;
384 	err = Isdnl1_Init(&debug);
385 	if (err)
386 		goto error3;
387 	err = Isdnl2_Init(&debug);
388 	if (err)
389 		goto error4;
390 	err = misdn_sock_init(&debug);
391 	if (err)
392 		goto error5;
393 	return 0;
394 
395 error5:
396 	Isdnl2_cleanup();
397 error4:
398 	Isdnl1_cleanup();
399 error3:
400 	mISDN_timer_cleanup();
401 error2:
402 	class_unregister(&mISDN_class);
403 error1:
404 	return err;
405 }
406 
407 static void mISDN_cleanup(void)
408 {
409 	misdn_sock_cleanup();
410 	Isdnl2_cleanup();
411 	Isdnl1_cleanup();
412 	mISDN_timer_cleanup();
413 	class_unregister(&mISDN_class);
414 
415 	printk(KERN_DEBUG "mISDNcore unloaded\n");
416 }
417 
418 module_init(mISDNInit);
419 module_exit(mISDN_cleanup);
420