xref: /linux/drivers/isdn/mISDN/core.c (revision af8e51644a70f612974a6e767fa7d896d3c23f88)
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_DESCRIPTION("Modular ISDN core driver");
18 MODULE_LICENSE("GPL");
19 module_param(debug, uint, S_IRUGO | S_IWUSR);
20 
21 static u64		device_ids;
22 #define MAX_DEVICE_ID	63
23 
24 static LIST_HEAD(Bprotocols);
25 static DEFINE_RWLOCK(bp_lock);
26 
27 static void mISDN_dev_release(struct device *dev)
28 {
29 	/* nothing to do: the device is part of its parent's data structure */
30 }
31 
32 static ssize_t id_show(struct device *dev,
33 		       struct device_attribute *attr, char *buf)
34 {
35 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
36 
37 	if (!mdev)
38 		return -ENODEV;
39 	return sprintf(buf, "%d\n", mdev->id);
40 }
41 static DEVICE_ATTR_RO(id);
42 
43 static ssize_t nrbchan_show(struct device *dev,
44 			    struct device_attribute *attr, char *buf)
45 {
46 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
47 
48 	if (!mdev)
49 		return -ENODEV;
50 	return sprintf(buf, "%d\n", mdev->nrbchan);
51 }
52 static DEVICE_ATTR_RO(nrbchan);
53 
54 static ssize_t d_protocols_show(struct device *dev,
55 				struct device_attribute *attr, char *buf)
56 {
57 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
58 
59 	if (!mdev)
60 		return -ENODEV;
61 	return sprintf(buf, "%d\n", mdev->Dprotocols);
62 }
63 static DEVICE_ATTR_RO(d_protocols);
64 
65 static ssize_t b_protocols_show(struct device *dev,
66 				struct device_attribute *attr, char *buf)
67 {
68 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
69 
70 	if (!mdev)
71 		return -ENODEV;
72 	return sprintf(buf, "%d\n", mdev->Bprotocols | get_all_Bprotocols());
73 }
74 static DEVICE_ATTR_RO(b_protocols);
75 
76 static ssize_t protocol_show(struct device *dev,
77 			     struct device_attribute *attr, char *buf)
78 {
79 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
80 
81 	if (!mdev)
82 		return -ENODEV;
83 	return sprintf(buf, "%d\n", mdev->D.protocol);
84 }
85 static DEVICE_ATTR_RO(protocol);
86 
87 static ssize_t name_show(struct device *dev,
88 			 struct device_attribute *attr, char *buf)
89 {
90 	strcpy(buf, dev_name(dev));
91 	return strlen(buf);
92 }
93 static DEVICE_ATTR_RO(name);
94 
95 #if 0 /* hangs */
96 static ssize_t name_set(struct device *dev, struct device_attribute *attr,
97 			const char *buf, size_t count)
98 {
99 	int err = 0;
100 	char *out = kmalloc(count + 1, GFP_KERNEL);
101 
102 	if (!out)
103 		return -ENOMEM;
104 
105 	memcpy(out, buf, count);
106 	if (count && out[count - 1] == '\n')
107 		out[--count] = 0;
108 	if (count)
109 		err = device_rename(dev, out);
110 	kfree(out);
111 
112 	return (err < 0) ? err : count;
113 }
114 static DEVICE_ATTR_RW(name);
115 #endif
116 
117 static ssize_t channelmap_show(struct device *dev,
118 			       struct device_attribute *attr, char *buf)
119 {
120 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
121 	char *bp = buf;
122 	int i;
123 
124 	for (i = 0; i <= mdev->nrbchan; i++)
125 		*bp++ = test_channelmap(i, mdev->channelmap) ? '1' : '0';
126 
127 	return bp - buf;
128 }
129 static DEVICE_ATTR_RO(channelmap);
130 
131 static struct attribute *mISDN_attrs[] = {
132 	&dev_attr_id.attr,
133 	&dev_attr_d_protocols.attr,
134 	&dev_attr_b_protocols.attr,
135 	&dev_attr_protocol.attr,
136 	&dev_attr_channelmap.attr,
137 	&dev_attr_nrbchan.attr,
138 	&dev_attr_name.attr,
139 	NULL,
140 };
141 ATTRIBUTE_GROUPS(mISDN);
142 
143 static int mISDN_uevent(const struct device *dev, struct kobj_uevent_env *env)
144 {
145 	const struct mISDNdevice *mdev = dev_to_mISDN(dev);
146 
147 	if (!mdev)
148 		return 0;
149 
150 	if (add_uevent_var(env, "nchans=%d", mdev->nrbchan))
151 		return -ENOMEM;
152 
153 	return 0;
154 }
155 
156 static struct class mISDN_class = {
157 	.name = "mISDN",
158 	.dev_uevent = mISDN_uevent,
159 	.dev_groups = mISDN_groups,
160 	.dev_release = mISDN_dev_release,
161 };
162 
163 static int
164 _get_mdevice(struct device *dev, const void *id)
165 {
166 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
167 
168 	if (!mdev)
169 		return 0;
170 	if (mdev->id != *(const u_int *)id)
171 		return 0;
172 	return 1;
173 }
174 
175 struct mISDNdevice
176 *get_mdevice(u_int id)
177 {
178 	return dev_to_mISDN(class_find_device(&mISDN_class, NULL, &id,
179 					      _get_mdevice));
180 }
181 
182 static int
183 _get_mdevice_count(struct device *dev, void *cnt)
184 {
185 	*(int *)cnt += 1;
186 	return 0;
187 }
188 
189 int
190 get_mdevice_count(void)
191 {
192 	int cnt = 0;
193 
194 	class_for_each_device(&mISDN_class, NULL, &cnt, _get_mdevice_count);
195 	return cnt;
196 }
197 
198 static int
199 get_free_devid(void)
200 {
201 	u_int	i;
202 
203 	for (i = 0; i <= MAX_DEVICE_ID; i++)
204 		if (!test_and_set_bit(i, (u_long *)&device_ids))
205 			break;
206 	if (i > MAX_DEVICE_ID)
207 		return -EBUSY;
208 	return i;
209 }
210 
211 int
212 mISDN_register_device(struct mISDNdevice *dev,
213 		      struct device *parent, char *name)
214 {
215 	int	err;
216 
217 	err = get_free_devid();
218 	if (err < 0)
219 		return err;
220 	dev->id = err;
221 
222 	device_initialize(&dev->dev);
223 	if (name && name[0])
224 		dev_set_name(&dev->dev, "%s", name);
225 	else
226 		dev_set_name(&dev->dev, "mISDN%d", dev->id);
227 	if (debug & DEBUG_CORE)
228 		printk(KERN_DEBUG "mISDN_register %s %d\n",
229 		       dev_name(&dev->dev), dev->id);
230 	dev->dev.class = &mISDN_class;
231 
232 	err = create_stack(dev);
233 	if (err)
234 		goto error1;
235 
236 	dev->dev.platform_data = dev;
237 	dev->dev.parent = parent;
238 	dev_set_drvdata(&dev->dev, dev);
239 
240 	err = device_add(&dev->dev);
241 	if (err)
242 		goto error3;
243 	return 0;
244 
245 error3:
246 	delete_stack(dev);
247 error1:
248 	put_device(&dev->dev);
249 	return err;
250 
251 }
252 EXPORT_SYMBOL(mISDN_register_device);
253 
254 void
255 mISDN_unregister_device(struct mISDNdevice *dev) {
256 	if (debug & DEBUG_CORE)
257 		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
258 		       dev_name(&dev->dev), dev->id);
259 	/* sysfs_remove_link(&dev->dev.kobj, "device"); */
260 	device_del(&dev->dev);
261 	dev_set_drvdata(&dev->dev, NULL);
262 
263 	test_and_clear_bit(dev->id, (u_long *)&device_ids);
264 	delete_stack(dev);
265 	put_device(&dev->dev);
266 }
267 EXPORT_SYMBOL(mISDN_unregister_device);
268 
269 u_int
270 get_all_Bprotocols(void)
271 {
272 	struct Bprotocol	*bp;
273 	u_int	m = 0;
274 
275 	read_lock(&bp_lock);
276 	list_for_each_entry(bp, &Bprotocols, list)
277 		m |= bp->Bprotocols;
278 	read_unlock(&bp_lock);
279 	return m;
280 }
281 
282 struct Bprotocol *
283 get_Bprotocol4mask(u_int m)
284 {
285 	struct Bprotocol	*bp;
286 
287 	read_lock(&bp_lock);
288 	list_for_each_entry(bp, &Bprotocols, list)
289 		if (bp->Bprotocols & m) {
290 			read_unlock(&bp_lock);
291 			return bp;
292 		}
293 	read_unlock(&bp_lock);
294 	return NULL;
295 }
296 
297 struct Bprotocol *
298 get_Bprotocol4id(u_int id)
299 {
300 	u_int	m;
301 
302 	if (id < ISDN_P_B_START || id > 63) {
303 		printk(KERN_WARNING "%s id not in range  %d\n",
304 		       __func__, id);
305 		return NULL;
306 	}
307 	m = 1 << (id & ISDN_P_B_MASK);
308 	return get_Bprotocol4mask(m);
309 }
310 
311 int
312 mISDN_register_Bprotocol(struct Bprotocol *bp)
313 {
314 	u_long			flags;
315 	struct Bprotocol	*old;
316 
317 	if (debug & DEBUG_CORE)
318 		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
319 		       bp->name, bp->Bprotocols);
320 	old = get_Bprotocol4mask(bp->Bprotocols);
321 	if (old) {
322 		printk(KERN_WARNING
323 		       "register duplicate protocol old %s/%x new %s/%x\n",
324 		       old->name, old->Bprotocols, bp->name, bp->Bprotocols);
325 		return -EBUSY;
326 	}
327 	write_lock_irqsave(&bp_lock, flags);
328 	list_add_tail(&bp->list, &Bprotocols);
329 	write_unlock_irqrestore(&bp_lock, flags);
330 	return 0;
331 }
332 EXPORT_SYMBOL(mISDN_register_Bprotocol);
333 
334 void
335 mISDN_unregister_Bprotocol(struct Bprotocol *bp)
336 {
337 	u_long	flags;
338 
339 	if (debug & DEBUG_CORE)
340 		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
341 		       bp->Bprotocols);
342 	write_lock_irqsave(&bp_lock, flags);
343 	list_del(&bp->list);
344 	write_unlock_irqrestore(&bp_lock, flags);
345 }
346 EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
347 
348 static const char *msg_no_channel = "<no channel>";
349 static const char *msg_no_stack = "<no stack>";
350 static const char *msg_no_stackdev = "<no stack device>";
351 
352 const char *mISDNDevName4ch(struct mISDNchannel *ch)
353 {
354 	if (!ch)
355 		return msg_no_channel;
356 	if (!ch->st)
357 		return msg_no_stack;
358 	if (!ch->st->dev)
359 		return msg_no_stackdev;
360 	return dev_name(&ch->st->dev->dev);
361 };
362 EXPORT_SYMBOL(mISDNDevName4ch);
363 
364 static int
365 mISDNInit(void)
366 {
367 	int	err;
368 
369 	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
370 	       MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
371 	mISDN_init_clock(&debug);
372 	mISDN_initstack(&debug);
373 	err = class_register(&mISDN_class);
374 	if (err)
375 		goto error1;
376 	err = mISDN_inittimer(&debug);
377 	if (err)
378 		goto error2;
379 	err = Isdnl1_Init(&debug);
380 	if (err)
381 		goto error3;
382 	err = Isdnl2_Init(&debug);
383 	if (err)
384 		goto error4;
385 	err = misdn_sock_init(&debug);
386 	if (err)
387 		goto error5;
388 	return 0;
389 
390 error5:
391 	Isdnl2_cleanup();
392 error4:
393 	Isdnl1_cleanup();
394 error3:
395 	mISDN_timer_cleanup();
396 error2:
397 	class_unregister(&mISDN_class);
398 error1:
399 	return err;
400 }
401 
402 static void mISDN_cleanup(void)
403 {
404 	misdn_sock_cleanup();
405 	Isdnl2_cleanup();
406 	Isdnl1_cleanup();
407 	mISDN_timer_cleanup();
408 	class_unregister(&mISDN_class);
409 
410 	printk(KERN_DEBUG "mISDNcore unloaded\n");
411 }
412 
413 module_init(mISDNInit);
414 module_exit(mISDN_cleanup);
415