1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * remote processor messaging bus
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 *
8 * Ohad Ben-Cohen <ohad@wizery.com>
9 * Brian Swetland <swetland@google.com>
10 */
11
12 #define pr_fmt(fmt) "%s: " fmt, __func__
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/rpmsg.h>
17 #include <linux/of_device.h>
18 #include <linux/pm_domain.h>
19 #include <linux/slab.h>
20
21 #include "rpmsg_internal.h"
22
23 /**
24 * rpmsg_create_ept() - create a new rpmsg_endpoint
25 * @rpdev: rpmsg channel device
26 * @cb: rx callback handler
27 * @priv: private data for the driver's use
28 * @chinfo: channel_info with the local rpmsg address to bind with @cb
29 *
30 * Every rpmsg address in the system is bound to an rx callback (so when
31 * inbound messages arrive, they are dispatched by the rpmsg bus using the
32 * appropriate callback handler) by means of an rpmsg_endpoint struct.
33 *
34 * This function allows drivers to create such an endpoint, and by that,
35 * bind a callback, and possibly some private data too, to an rpmsg address
36 * (either one that is known in advance, or one that will be dynamically
37 * assigned for them).
38 *
39 * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint
40 * is already created for them when they are probed by the rpmsg bus
41 * (using the rx callback provided when they registered to the rpmsg bus).
42 *
43 * So things should just work for simple drivers: they already have an
44 * endpoint, their rx callback is bound to their rpmsg address, and when
45 * relevant inbound messages arrive (i.e. messages which their dst address
46 * equals to the src address of their rpmsg channel), the driver's handler
47 * is invoked to process it.
48 *
49 * That said, more complicated drivers might need to allocate
50 * additional rpmsg addresses, and bind them to different rx callbacks.
51 * To accomplish that, those drivers need to call this function.
52 *
53 * Drivers should provide their @rpdev channel (so the new endpoint would belong
54 * to the same remote processor their channel belongs to), an rx callback
55 * function, an optional private data (which is provided back when the
56 * rx callback is invoked), and an address they want to bind with the
57 * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will
58 * dynamically assign them an available rpmsg address (drivers should have
59 * a very good reason why not to always use RPMSG_ADDR_ANY here).
60 *
61 * Returns a pointer to the endpoint on success, or NULL on error.
62 */
rpmsg_create_ept(struct rpmsg_device * rpdev,rpmsg_rx_cb_t cb,void * priv,struct rpmsg_channel_info chinfo)63 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
64 rpmsg_rx_cb_t cb, void *priv,
65 struct rpmsg_channel_info chinfo)
66 {
67 if (WARN_ON(!rpdev))
68 return NULL;
69
70 return rpdev->ops->create_ept(rpdev, cb, priv, chinfo);
71 }
72 EXPORT_SYMBOL(rpmsg_create_ept);
73
74 /**
75 * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
76 * @ept: endpoing to destroy
77 *
78 * Should be used by drivers to destroy an rpmsg endpoint previously
79 * created with rpmsg_create_ept(). As with other types of "free" NULL
80 * is a valid parameter.
81 */
rpmsg_destroy_ept(struct rpmsg_endpoint * ept)82 void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
83 {
84 if (ept && ept->ops)
85 ept->ops->destroy_ept(ept);
86 }
87 EXPORT_SYMBOL(rpmsg_destroy_ept);
88
89 /**
90 * rpmsg_send() - send a message across to the remote processor
91 * @ept: the rpmsg endpoint
92 * @data: payload of message
93 * @len: length of payload
94 *
95 * This function sends @data of length @len on the @ept endpoint.
96 * The message will be sent to the remote processor which the @ept
97 * endpoint belongs to, using @ept's address and its associated rpmsg
98 * device destination addresses.
99 * In case there are no TX buffers available, the function will block until
100 * one becomes available, or a timeout of 15 seconds elapses. When the latter
101 * happens, -ERESTARTSYS is returned.
102 *
103 * Can only be called from process context (for now).
104 *
105 * Returns 0 on success and an appropriate error value on failure.
106 */
rpmsg_send(struct rpmsg_endpoint * ept,void * data,int len)107 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
108 {
109 if (WARN_ON(!ept))
110 return -EINVAL;
111 if (!ept->ops->send)
112 return -ENXIO;
113
114 return ept->ops->send(ept, data, len);
115 }
116 EXPORT_SYMBOL(rpmsg_send);
117
118 /**
119 * rpmsg_sendto() - send a message across to the remote processor, specify dst
120 * @ept: the rpmsg endpoint
121 * @data: payload of message
122 * @len: length of payload
123 * @dst: destination address
124 *
125 * This function sends @data of length @len to the remote @dst address.
126 * The message will be sent to the remote processor which the @ept
127 * endpoint belongs to, using @ept's address as source.
128 * In case there are no TX buffers available, the function will block until
129 * one becomes available, or a timeout of 15 seconds elapses. When the latter
130 * happens, -ERESTARTSYS is returned.
131 *
132 * Can only be called from process context (for now).
133 *
134 * Returns 0 on success and an appropriate error value on failure.
135 */
rpmsg_sendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)136 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
137 {
138 if (WARN_ON(!ept))
139 return -EINVAL;
140 if (!ept->ops->sendto)
141 return -ENXIO;
142
143 return ept->ops->sendto(ept, data, len, dst);
144 }
145 EXPORT_SYMBOL(rpmsg_sendto);
146
147 /**
148 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
149 * @ept: the rpmsg endpoint
150 * @src: source address
151 * @dst: destination address
152 * @data: payload of message
153 * @len: length of payload
154 *
155 * This function sends @data of length @len to the remote @dst address,
156 * and uses @src as the source address.
157 * The message will be sent to the remote processor which the @ept
158 * endpoint belongs to.
159 * In case there are no TX buffers available, the function will block until
160 * one becomes available, or a timeout of 15 seconds elapses. When the latter
161 * happens, -ERESTARTSYS is returned.
162 *
163 * Can only be called from process context (for now).
164 *
165 * Returns 0 on success and an appropriate error value on failure.
166 */
rpmsg_send_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)167 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
168 void *data, int len)
169 {
170 if (WARN_ON(!ept))
171 return -EINVAL;
172 if (!ept->ops->send_offchannel)
173 return -ENXIO;
174
175 return ept->ops->send_offchannel(ept, src, dst, data, len);
176 }
177 EXPORT_SYMBOL(rpmsg_send_offchannel);
178
179 /**
180 * rpmsg_trysend() - send a message across to the remote processor
181 * @ept: the rpmsg endpoint
182 * @data: payload of message
183 * @len: length of payload
184 *
185 * This function sends @data of length @len on the @ept endpoint.
186 * The message will be sent to the remote processor which the @ept
187 * endpoint belongs to, using @ept's address as source and its associated
188 * rpdev's address as destination.
189 * In case there are no TX buffers available, the function will immediately
190 * return -ENOMEM without waiting until one becomes available.
191 *
192 * Can only be called from process context (for now).
193 *
194 * Returns 0 on success and an appropriate error value on failure.
195 */
rpmsg_trysend(struct rpmsg_endpoint * ept,void * data,int len)196 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
197 {
198 if (WARN_ON(!ept))
199 return -EINVAL;
200 if (!ept->ops->trysend)
201 return -ENXIO;
202
203 return ept->ops->trysend(ept, data, len);
204 }
205 EXPORT_SYMBOL(rpmsg_trysend);
206
207 /**
208 * rpmsg_trysendto() - send a message across to the remote processor, specify dst
209 * @ept: the rpmsg endpoint
210 * @data: payload of message
211 * @len: length of payload
212 * @dst: destination address
213 *
214 * This function sends @data of length @len to the remote @dst address.
215 * The message will be sent to the remote processor which the @ept
216 * endpoint belongs to, using @ept's address as source.
217 * In case there are no TX buffers available, the function will immediately
218 * return -ENOMEM without waiting until one becomes available.
219 *
220 * Can only be called from process context (for now).
221 *
222 * Returns 0 on success and an appropriate error value on failure.
223 */
rpmsg_trysendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)224 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
225 {
226 if (WARN_ON(!ept))
227 return -EINVAL;
228 if (!ept->ops->trysendto)
229 return -ENXIO;
230
231 return ept->ops->trysendto(ept, data, len, dst);
232 }
233 EXPORT_SYMBOL(rpmsg_trysendto);
234
235 /**
236 * rpmsg_poll() - poll the endpoint's send buffers
237 * @ept: the rpmsg endpoint
238 * @filp: file for poll_wait()
239 * @wait: poll_table for poll_wait()
240 *
241 * Returns mask representing the current state of the endpoint's send buffers
242 */
rpmsg_poll(struct rpmsg_endpoint * ept,struct file * filp,poll_table * wait)243 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
244 poll_table *wait)
245 {
246 if (WARN_ON(!ept))
247 return 0;
248 if (!ept->ops->poll)
249 return 0;
250
251 return ept->ops->poll(ept, filp, wait);
252 }
253 EXPORT_SYMBOL(rpmsg_poll);
254
255 /**
256 * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
257 * @ept: the rpmsg endpoint
258 * @src: source address
259 * @dst: destination address
260 * @data: payload of message
261 * @len: length of payload
262 *
263 * This function sends @data of length @len to the remote @dst address,
264 * and uses @src as the source address.
265 * The message will be sent to the remote processor which the @ept
266 * endpoint belongs to.
267 * In case there are no TX buffers available, the function will immediately
268 * return -ENOMEM without waiting until one becomes available.
269 *
270 * Can only be called from process context (for now).
271 *
272 * Returns 0 on success and an appropriate error value on failure.
273 */
rpmsg_trysend_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)274 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
275 void *data, int len)
276 {
277 if (WARN_ON(!ept))
278 return -EINVAL;
279 if (!ept->ops->trysend_offchannel)
280 return -ENXIO;
281
282 return ept->ops->trysend_offchannel(ept, src, dst, data, len);
283 }
284 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
285
286 /**
287 * rpmsg_get_signals() - get the signals for this endpoint
288 * @ept: the rpmsg endpoint
289 *
290 * Returns signal bits on success and an appropriate error value on failure.
291 */
rpmsg_get_signals(struct rpmsg_endpoint * ept)292 int rpmsg_get_signals(struct rpmsg_endpoint *ept)
293 {
294 if (WARN_ON(!ept))
295 return -EINVAL;
296 if (!ept->ops->get_signals)
297 return -ENXIO;
298
299 return ept->ops->get_signals(ept);
300 }
301 EXPORT_SYMBOL(rpmsg_get_signals);
302
303 /**
304 * rpmsg_set_signals() - set the remote signals for this endpoint
305 * @ept: the rpmsg endpoint
306 * @set: set mask for signals
307 * @clear: clear mask for signals
308 *
309 * Returns 0 on success and an appropriate error value on failure.
310 */
rpmsg_set_signals(struct rpmsg_endpoint * ept,u32 set,u32 clear)311 int rpmsg_set_signals(struct rpmsg_endpoint *ept, u32 set, u32 clear)
312 {
313 if (WARN_ON(!ept))
314 return -EINVAL;
315 if (!ept->ops->set_signals)
316 return -ENXIO;
317
318 return ept->ops->set_signals(ept, set, clear);
319 }
320 EXPORT_SYMBOL(rpmsg_set_signals);
321
322 /*
323 * match a rpmsg channel with a channel info struct.
324 * this is used to make sure we're not creating rpmsg devices for channels
325 * that already exist.
326 */
rpmsg_device_match(struct device * dev,void * data)327 static int rpmsg_device_match(struct device *dev, void *data)
328 {
329 struct rpmsg_channel_info *chinfo = data;
330 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
331
332 if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src)
333 return 0;
334
335 if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst)
336 return 0;
337
338 if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE))
339 return 0;
340
341 /* found a match ! */
342 return 1;
343 }
344
rpmsg_find_device(struct device * parent,struct rpmsg_channel_info * chinfo)345 struct device *rpmsg_find_device(struct device *parent,
346 struct rpmsg_channel_info *chinfo)
347 {
348 return device_find_child(parent, chinfo, rpmsg_device_match);
349
350 }
351 EXPORT_SYMBOL(rpmsg_find_device);
352
353 /* sysfs show configuration fields */
354 #define rpmsg_show_attr(field, path, format_string) \
355 static ssize_t \
356 field##_show(struct device *dev, \
357 struct device_attribute *attr, char *buf) \
358 { \
359 struct rpmsg_device *rpdev = to_rpmsg_device(dev); \
360 \
361 return sprintf(buf, format_string, rpdev->path); \
362 } \
363 static DEVICE_ATTR_RO(field);
364
365 #define rpmsg_string_attr(field, member) \
366 static ssize_t \
367 field##_store(struct device *dev, struct device_attribute *attr, \
368 const char *buf, size_t sz) \
369 { \
370 struct rpmsg_device *rpdev = to_rpmsg_device(dev); \
371 char *new, *old; \
372 \
373 new = kstrndup(buf, sz, GFP_KERNEL); \
374 if (!new) \
375 return -ENOMEM; \
376 new[strcspn(new, "\n")] = '\0'; \
377 \
378 device_lock(dev); \
379 old = rpdev->member; \
380 if (strlen(new)) { \
381 rpdev->member = new; \
382 } else { \
383 kfree(new); \
384 rpdev->member = NULL; \
385 } \
386 device_unlock(dev); \
387 \
388 kfree(old); \
389 \
390 return sz; \
391 } \
392 static ssize_t \
393 field##_show(struct device *dev, \
394 struct device_attribute *attr, char *buf) \
395 { \
396 struct rpmsg_device *rpdev = to_rpmsg_device(dev); \
397 \
398 return sprintf(buf, "%s\n", rpdev->member); \
399 } \
400 static DEVICE_ATTR_RW(field)
401
402 /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */
403 rpmsg_show_attr(name, id.name, "%s\n");
404 rpmsg_show_attr(src, src, "0x%x\n");
405 rpmsg_show_attr(dst, dst, "0x%x\n");
406 rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
407 rpmsg_string_attr(driver_override, driver_override);
408
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)409 static ssize_t modalias_show(struct device *dev,
410 struct device_attribute *attr, char *buf)
411 {
412 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
413 ssize_t len;
414
415 len = of_device_modalias(dev, buf, PAGE_SIZE);
416 if (len != -ENODEV)
417 return len;
418
419 return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name);
420 }
421 static DEVICE_ATTR_RO(modalias);
422
423 static struct attribute *rpmsg_dev_attrs[] = {
424 &dev_attr_name.attr,
425 &dev_attr_modalias.attr,
426 &dev_attr_dst.attr,
427 &dev_attr_src.attr,
428 &dev_attr_announce.attr,
429 &dev_attr_driver_override.attr,
430 NULL,
431 };
432 ATTRIBUTE_GROUPS(rpmsg_dev);
433
434 /* rpmsg devices and drivers are matched using the service name */
rpmsg_id_match(const struct rpmsg_device * rpdev,const struct rpmsg_device_id * id)435 static inline int rpmsg_id_match(const struct rpmsg_device *rpdev,
436 const struct rpmsg_device_id *id)
437 {
438 return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0;
439 }
440
441 /* match rpmsg channel and rpmsg driver */
rpmsg_dev_match(struct device * dev,struct device_driver * drv)442 static int rpmsg_dev_match(struct device *dev, struct device_driver *drv)
443 {
444 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
445 struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv);
446 const struct rpmsg_device_id *ids = rpdrv->id_table;
447 unsigned int i;
448
449 if (rpdev->driver_override)
450 return !strcmp(rpdev->driver_override, drv->name);
451
452 if (ids)
453 for (i = 0; ids[i].name[0]; i++)
454 if (rpmsg_id_match(rpdev, &ids[i]))
455 return 1;
456
457 return of_driver_match_device(dev, drv);
458 }
459
rpmsg_uevent(struct device * dev,struct kobj_uevent_env * env)460 static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env)
461 {
462 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
463 int ret;
464
465 ret = of_device_uevent_modalias(dev, env);
466 if (ret != -ENODEV)
467 return ret;
468
469 return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT,
470 rpdev->id.name);
471 }
472
473 /*
474 * when an rpmsg driver is probed with a channel, we seamlessly create
475 * it an endpoint, binding its rx callback to a unique local rpmsg
476 * address.
477 *
478 * if we need to, we also announce about this channel to the remote
479 * processor (needed in case the driver is exposing an rpmsg service).
480 */
rpmsg_dev_probe(struct device * dev)481 static int rpmsg_dev_probe(struct device *dev)
482 {
483 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
484 struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
485 struct rpmsg_channel_info chinfo = {};
486 struct rpmsg_endpoint *ept = NULL;
487 int err;
488
489 err = dev_pm_domain_attach(dev, true);
490 if (err)
491 goto out;
492
493 if (rpdrv->callback) {
494 strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
495 chinfo.src = rpdev->src;
496 chinfo.dst = RPMSG_ADDR_ANY;
497
498 ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo);
499 if (!ept) {
500 dev_err(dev, "failed to create endpoint\n");
501 err = -ENOMEM;
502 goto out;
503 }
504
505 rpdev->ept = ept;
506 rpdev->src = ept->addr;
507
508 if (rpdrv->signals)
509 ept->sig_cb = rpdrv->signals;
510
511 }
512
513 err = rpdrv->probe(rpdev);
514 if (err) {
515 dev_err(dev, "%s: failed: %d\n", __func__, err);
516 goto destroy_ept;
517 }
518
519 if (ept && rpdev->ops->announce_create) {
520 err = rpdev->ops->announce_create(rpdev);
521 if (err) {
522 dev_err(dev, "failed to announce creation\n");
523 goto remove_rpdev;
524 }
525 }
526
527 return 0;
528
529 remove_rpdev:
530 if (rpdrv->remove)
531 rpdrv->remove(rpdev);
532 destroy_ept:
533 if (ept)
534 rpmsg_destroy_ept(ept);
535 out:
536 return err;
537 }
538
rpmsg_dev_remove(struct device * dev)539 static int rpmsg_dev_remove(struct device *dev)
540 {
541 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
542 struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
543 int err = 0;
544
545 if (rpdev->ops->announce_destroy)
546 err = rpdev->ops->announce_destroy(rpdev);
547
548 if (rpdrv->remove)
549 rpdrv->remove(rpdev);
550
551 dev_pm_domain_detach(dev, true);
552
553 if (rpdev->ept)
554 rpmsg_destroy_ept(rpdev->ept);
555
556 return err;
557 }
558
559 static struct bus_type rpmsg_bus = {
560 .name = "rpmsg",
561 .match = rpmsg_dev_match,
562 .dev_groups = rpmsg_dev_groups,
563 .uevent = rpmsg_uevent,
564 .probe = rpmsg_dev_probe,
565 .remove = rpmsg_dev_remove,
566 };
567
rpmsg_register_device(struct rpmsg_device * rpdev)568 int rpmsg_register_device(struct rpmsg_device *rpdev)
569 {
570 struct device *dev = &rpdev->dev;
571 int ret;
572
573 dev_set_name(&rpdev->dev, "%s.%s.%d.%d", dev_name(dev->parent),
574 rpdev->id.name, rpdev->src, rpdev->dst);
575
576 rpdev->dev.bus = &rpmsg_bus;
577
578 ret = device_register(&rpdev->dev);
579 if (ret) {
580 dev_err(dev, "device_register failed: %d\n", ret);
581 put_device(&rpdev->dev);
582 }
583
584 return ret;
585 }
586 EXPORT_SYMBOL(rpmsg_register_device);
587
588 /*
589 * find an existing channel using its name + address properties,
590 * and destroy it
591 */
rpmsg_unregister_device(struct device * parent,struct rpmsg_channel_info * chinfo)592 int rpmsg_unregister_device(struct device *parent,
593 struct rpmsg_channel_info *chinfo)
594 {
595 struct device *dev;
596
597 dev = rpmsg_find_device(parent, chinfo);
598 if (!dev)
599 return -EINVAL;
600
601 device_unregister(dev);
602
603 put_device(dev);
604
605 return 0;
606 }
607 EXPORT_SYMBOL(rpmsg_unregister_device);
608
609 /**
610 * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus
611 * @rpdrv: pointer to a struct rpmsg_driver
612 * @owner: owning module/driver
613 *
614 * Returns 0 on success, and an appropriate error value on failure.
615 */
__register_rpmsg_driver(struct rpmsg_driver * rpdrv,struct module * owner)616 int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner)
617 {
618 rpdrv->drv.bus = &rpmsg_bus;
619 rpdrv->drv.owner = owner;
620 return driver_register(&rpdrv->drv);
621 }
622 EXPORT_SYMBOL(__register_rpmsg_driver);
623
624 /**
625 * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus
626 * @rpdrv: pointer to a struct rpmsg_driver
627 *
628 * Returns 0 on success, and an appropriate error value on failure.
629 */
unregister_rpmsg_driver(struct rpmsg_driver * rpdrv)630 void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv)
631 {
632 driver_unregister(&rpdrv->drv);
633 }
634 EXPORT_SYMBOL(unregister_rpmsg_driver);
635
636
rpmsg_init(void)637 static int __init rpmsg_init(void)
638 {
639 int ret;
640
641 ret = bus_register(&rpmsg_bus);
642 if (ret)
643 pr_err("failed to register rpmsg bus: %d\n", ret);
644
645 return ret;
646 }
647 postcore_initcall(rpmsg_init);
648
rpmsg_fini(void)649 static void __exit rpmsg_fini(void)
650 {
651 bus_unregister(&rpmsg_bus);
652 }
653 module_exit(rpmsg_fini);
654
655 MODULE_DESCRIPTION("remote processor messaging bus");
656 MODULE_LICENSE("GPL v2");
657