xref: /linux/drivers/rpmsg/rpmsg_core.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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 const struct class rpmsg_class = {
24 	.name = "rpmsg",
25 };
26 EXPORT_SYMBOL(rpmsg_class);
27 
28 /**
29  * rpmsg_create_channel() - create a new rpmsg channel
30  * using its name and address info.
31  * @rpdev: rpmsg device
32  * @chinfo: channel_info to bind
33  *
34  * Return: a pointer to the new rpmsg device on success, or NULL on error.
35  */
rpmsg_create_channel(struct rpmsg_device * rpdev,struct rpmsg_channel_info * chinfo)36 struct rpmsg_device *rpmsg_create_channel(struct rpmsg_device *rpdev,
37 					  struct rpmsg_channel_info *chinfo)
38 {
39 	if (WARN_ON(!rpdev))
40 		return NULL;
41 	if (!rpdev->ops || !rpdev->ops->create_channel) {
42 		dev_err(&rpdev->dev, "no create_channel ops found\n");
43 		return NULL;
44 	}
45 
46 	return rpdev->ops->create_channel(rpdev, chinfo);
47 }
48 EXPORT_SYMBOL(rpmsg_create_channel);
49 
50 /**
51  * rpmsg_release_channel() - release a rpmsg channel
52  * using its name and address info.
53  * @rpdev: rpmsg device
54  * @chinfo: channel_info to bind
55  *
56  * Return: 0 on success or an appropriate error value.
57  */
rpmsg_release_channel(struct rpmsg_device * rpdev,struct rpmsg_channel_info * chinfo)58 int rpmsg_release_channel(struct rpmsg_device *rpdev,
59 			  struct rpmsg_channel_info *chinfo)
60 {
61 	if (WARN_ON(!rpdev))
62 		return -EINVAL;
63 	if (!rpdev->ops || !rpdev->ops->release_channel) {
64 		dev_err(&rpdev->dev, "no release_channel ops found\n");
65 		return -ENXIO;
66 	}
67 
68 	return rpdev->ops->release_channel(rpdev, chinfo);
69 }
70 EXPORT_SYMBOL(rpmsg_release_channel);
71 
72 /**
73  * rpmsg_create_ept() - create a new rpmsg_endpoint
74  * @rpdev: rpmsg channel device
75  * @cb: rx callback handler
76  * @priv: private data for the driver's use
77  * @chinfo: channel_info with the local rpmsg address to bind with @cb
78  *
79  * Every rpmsg address in the system is bound to an rx callback (so when
80  * inbound messages arrive, they are dispatched by the rpmsg bus using the
81  * appropriate callback handler) by means of an rpmsg_endpoint struct.
82  *
83  * This function allows drivers to create such an endpoint, and by that,
84  * bind a callback, and possibly some private data too, to an rpmsg address
85  * (either one that is known in advance, or one that will be dynamically
86  * assigned for them).
87  *
88  * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint
89  * is already created for them when they are probed by the rpmsg bus
90  * (using the rx callback provided when they registered to the rpmsg bus).
91  *
92  * So things should just work for simple drivers: they already have an
93  * endpoint, their rx callback is bound to their rpmsg address, and when
94  * relevant inbound messages arrive (i.e. messages which their dst address
95  * equals to the src address of their rpmsg channel), the driver's handler
96  * is invoked to process it.
97  *
98  * That said, more complicated drivers might need to allocate
99  * additional rpmsg addresses, and bind them to different rx callbacks.
100  * To accomplish that, those drivers need to call this function.
101  *
102  * Drivers should provide their @rpdev channel (so the new endpoint would belong
103  * to the same remote processor their channel belongs to), an rx callback
104  * function, an optional private data (which is provided back when the
105  * rx callback is invoked), and an address they want to bind with the
106  * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will
107  * dynamically assign them an available rpmsg address (drivers should have
108  * a very good reason why not to always use RPMSG_ADDR_ANY here).
109  *
110  * Return: a pointer to the endpoint on success, or NULL on error.
111  */
rpmsg_create_ept(struct rpmsg_device * rpdev,rpmsg_rx_cb_t cb,void * priv,struct rpmsg_channel_info chinfo)112 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
113 					rpmsg_rx_cb_t cb, void *priv,
114 					struct rpmsg_channel_info chinfo)
115 {
116 	if (WARN_ON(!rpdev))
117 		return NULL;
118 
119 	return rpdev->ops->create_ept(rpdev, cb, priv, chinfo);
120 }
121 EXPORT_SYMBOL(rpmsg_create_ept);
122 
123 /**
124  * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
125  * @ept: endpoing to destroy
126  *
127  * Should be used by drivers to destroy an rpmsg endpoint previously
128  * created with rpmsg_create_ept(). As with other types of "free" NULL
129  * is a valid parameter.
130  */
rpmsg_destroy_ept(struct rpmsg_endpoint * ept)131 void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
132 {
133 	if (ept && ept->ops)
134 		ept->ops->destroy_ept(ept);
135 }
136 EXPORT_SYMBOL(rpmsg_destroy_ept);
137 
138 /**
139  * rpmsg_send() - send a message across to the remote processor
140  * @ept: the rpmsg endpoint
141  * @data: payload of message
142  * @len: length of payload
143  *
144  * This function sends @data of length @len on the @ept endpoint.
145  * The message will be sent to the remote processor which the @ept
146  * endpoint belongs to, using @ept's address and its associated rpmsg
147  * device destination addresses.
148  * In case there are no TX buffers available, the function will block until
149  * one becomes available, or a timeout of 15 seconds elapses. When the latter
150  * happens, -ERESTARTSYS is returned.
151  *
152  * Can only be called from process context (for now).
153  *
154  * Return: 0 on success and an appropriate error value on failure.
155  */
rpmsg_send(struct rpmsg_endpoint * ept,void * data,int len)156 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
157 {
158 	if (WARN_ON(!ept))
159 		return -EINVAL;
160 	if (!ept->ops->send)
161 		return -ENXIO;
162 
163 	return ept->ops->send(ept, data, len);
164 }
165 EXPORT_SYMBOL(rpmsg_send);
166 
167 /**
168  * rpmsg_sendto() - send a message across to the remote processor, specify dst
169  * @ept: the rpmsg endpoint
170  * @data: payload of message
171  * @len: length of payload
172  * @dst: destination address
173  *
174  * This function sends @data of length @len to the remote @dst address.
175  * The message will be sent to the remote processor which the @ept
176  * endpoint belongs to, using @ept's address as source.
177  * In case there are no TX buffers available, the function will block until
178  * one becomes available, or a timeout of 15 seconds elapses. When the latter
179  * happens, -ERESTARTSYS is returned.
180  *
181  * Can only be called from process context (for now).
182  *
183  * Return: 0 on success and an appropriate error value on failure.
184  */
rpmsg_sendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)185 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
186 {
187 	if (WARN_ON(!ept))
188 		return -EINVAL;
189 	if (!ept->ops->sendto)
190 		return -ENXIO;
191 
192 	return ept->ops->sendto(ept, data, len, dst);
193 }
194 EXPORT_SYMBOL(rpmsg_sendto);
195 
196 /**
197  * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
198  * @ept: the rpmsg endpoint
199  * @src: source address
200  * @dst: destination address
201  * @data: payload of message
202  * @len: length of payload
203  *
204  * This function sends @data of length @len to the remote @dst address,
205  * and uses @src as the source address.
206  * The message will be sent to the remote processor which the @ept
207  * endpoint belongs to.
208  * In case there are no TX buffers available, the function will block until
209  * one becomes available, or a timeout of 15 seconds elapses. When the latter
210  * happens, -ERESTARTSYS is returned.
211  *
212  * Can only be called from process context (for now).
213  *
214  * Return: 0 on success and an appropriate error value on failure.
215  */
rpmsg_send_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)216 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
217 			  void *data, int len)
218 {
219 	if (WARN_ON(!ept))
220 		return -EINVAL;
221 	if (!ept->ops->send_offchannel)
222 		return -ENXIO;
223 
224 	return ept->ops->send_offchannel(ept, src, dst, data, len);
225 }
226 EXPORT_SYMBOL(rpmsg_send_offchannel);
227 
228 /**
229  * rpmsg_trysend() - send a message across to the remote processor
230  * @ept: the rpmsg endpoint
231  * @data: payload of message
232  * @len: length of payload
233  *
234  * This function sends @data of length @len on the @ept endpoint.
235  * The message will be sent to the remote processor which the @ept
236  * endpoint belongs to, using @ept's address as source and its associated
237  * rpdev's address as destination.
238  * In case there are no TX buffers available, the function will immediately
239  * return -ENOMEM without waiting until one becomes available.
240  *
241  * Can only be called from process context (for now).
242  *
243  * Return: 0 on success and an appropriate error value on failure.
244  */
rpmsg_trysend(struct rpmsg_endpoint * ept,void * data,int len)245 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
246 {
247 	if (WARN_ON(!ept))
248 		return -EINVAL;
249 	if (!ept->ops->trysend)
250 		return -ENXIO;
251 
252 	return ept->ops->trysend(ept, data, len);
253 }
254 EXPORT_SYMBOL(rpmsg_trysend);
255 
256 /**
257  * rpmsg_trysendto() - send a message across to the remote processor, specify dst
258  * @ept: the rpmsg endpoint
259  * @data: payload of message
260  * @len: length of payload
261  * @dst: destination address
262  *
263  * This function sends @data of length @len to the remote @dst address.
264  * The message will be sent to the remote processor which the @ept
265  * endpoint belongs to, using @ept's address as source.
266  * In case there are no TX buffers available, the function will immediately
267  * return -ENOMEM without waiting until one becomes available.
268  *
269  * Can only be called from process context (for now).
270  *
271  * Return: 0 on success and an appropriate error value on failure.
272  */
rpmsg_trysendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)273 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
274 {
275 	if (WARN_ON(!ept))
276 		return -EINVAL;
277 	if (!ept->ops->trysendto)
278 		return -ENXIO;
279 
280 	return ept->ops->trysendto(ept, data, len, dst);
281 }
282 EXPORT_SYMBOL(rpmsg_trysendto);
283 
284 /**
285  * rpmsg_poll() - poll the endpoint's send buffers
286  * @ept:	the rpmsg endpoint
287  * @filp:	file for poll_wait()
288  * @wait:	poll_table for poll_wait()
289  *
290  * Return: mask representing the current state of the endpoint's send buffers
291  */
rpmsg_poll(struct rpmsg_endpoint * ept,struct file * filp,poll_table * wait)292 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
293 			poll_table *wait)
294 {
295 	if (WARN_ON(!ept))
296 		return 0;
297 	if (!ept->ops->poll)
298 		return 0;
299 
300 	return ept->ops->poll(ept, filp, wait);
301 }
302 EXPORT_SYMBOL(rpmsg_poll);
303 
304 /**
305  * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
306  * @ept: the rpmsg endpoint
307  * @src: source address
308  * @dst: destination address
309  * @data: payload of message
310  * @len: length of payload
311  *
312  * This function sends @data of length @len to the remote @dst address,
313  * and uses @src as the source address.
314  * The message will be sent to the remote processor which the @ept
315  * endpoint belongs to.
316  * In case there are no TX buffers available, the function will immediately
317  * return -ENOMEM without waiting until one becomes available.
318  *
319  * Can only be called from process context (for now).
320  *
321  * Return: 0 on success and an appropriate error value on failure.
322  */
rpmsg_trysend_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)323 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
324 			     void *data, int len)
325 {
326 	if (WARN_ON(!ept))
327 		return -EINVAL;
328 	if (!ept->ops->trysend_offchannel)
329 		return -ENXIO;
330 
331 	return ept->ops->trysend_offchannel(ept, src, dst, data, len);
332 }
333 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
334 
335 /**
336  * rpmsg_set_flow_control() - request remote to pause/resume transmission
337  * @ept:	the rpmsg endpoint
338  * @pause:	pause transmission
339  * @dst:	destination address of the endpoint
340  *
341  * Return: 0 on success and an appropriate error value on failure.
342  */
rpmsg_set_flow_control(struct rpmsg_endpoint * ept,bool pause,u32 dst)343 int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
344 {
345 	if (WARN_ON(!ept))
346 		return -EINVAL;
347 	if (!ept->ops->set_flow_control)
348 		return -EOPNOTSUPP;
349 
350 	return ept->ops->set_flow_control(ept, pause, dst);
351 }
352 EXPORT_SYMBOL_GPL(rpmsg_set_flow_control);
353 
354 /**
355  * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
356  * @ept: the rpmsg endpoint
357  *
358  * This function returns maximum buffer size available for a single outgoing message.
359  *
360  * Return: the maximum transmission size on success and an appropriate error
361  * value on failure.
362  */
363 
rpmsg_get_mtu(struct rpmsg_endpoint * ept)364 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
365 {
366 	if (WARN_ON(!ept))
367 		return -EINVAL;
368 	if (!ept->ops->get_mtu)
369 		return -ENOTSUPP;
370 
371 	return ept->ops->get_mtu(ept);
372 }
373 EXPORT_SYMBOL(rpmsg_get_mtu);
374 
375 /*
376  * match a rpmsg channel with a channel info struct.
377  * this is used to make sure we're not creating rpmsg devices for channels
378  * that already exist.
379  */
rpmsg_device_match(struct device * dev,void * data)380 static int rpmsg_device_match(struct device *dev, void *data)
381 {
382 	struct rpmsg_channel_info *chinfo = data;
383 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
384 
385 	if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src)
386 		return 0;
387 
388 	if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst)
389 		return 0;
390 
391 	if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE))
392 		return 0;
393 
394 	/* found a match ! */
395 	return 1;
396 }
397 
rpmsg_find_device(struct device * parent,struct rpmsg_channel_info * chinfo)398 struct device *rpmsg_find_device(struct device *parent,
399 				 struct rpmsg_channel_info *chinfo)
400 {
401 	return device_find_child(parent, chinfo, rpmsg_device_match);
402 
403 }
404 EXPORT_SYMBOL(rpmsg_find_device);
405 
406 /* sysfs show configuration fields */
407 #define rpmsg_show_attr(field, path, format_string)			\
408 static ssize_t								\
409 field##_show(struct device *dev,					\
410 			struct device_attribute *attr, char *buf)	\
411 {									\
412 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
413 									\
414 	return sprintf(buf, format_string, rpdev->path);		\
415 }									\
416 static DEVICE_ATTR_RO(field);
417 
418 #define rpmsg_string_attr(field, member)				\
419 static ssize_t								\
420 field##_store(struct device *dev, struct device_attribute *attr,	\
421 	      const char *buf, size_t sz)				\
422 {									\
423 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
424 	const char *old;						\
425 	char *new;							\
426 									\
427 	new = kstrndup(buf, sz, GFP_KERNEL);				\
428 	if (!new)							\
429 		return -ENOMEM;						\
430 	new[strcspn(new, "\n")] = '\0';					\
431 									\
432 	device_lock(dev);						\
433 	old = rpdev->member;						\
434 	if (strlen(new)) {						\
435 		rpdev->member = new;					\
436 	} else {							\
437 		kfree(new);						\
438 		rpdev->member = NULL;					\
439 	}								\
440 	device_unlock(dev);						\
441 									\
442 	kfree(old);							\
443 									\
444 	return sz;							\
445 }									\
446 static ssize_t								\
447 field##_show(struct device *dev,					\
448 	     struct device_attribute *attr, char *buf)			\
449 {									\
450 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
451 									\
452 	return sprintf(buf, "%s\n", rpdev->member);			\
453 }									\
454 static DEVICE_ATTR_RW(field)
455 
456 /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */
457 rpmsg_show_attr(name, id.name, "%s\n");
458 rpmsg_show_attr(src, src, "0x%x\n");
459 rpmsg_show_attr(dst, dst, "0x%x\n");
460 rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
461 rpmsg_string_attr(driver_override, driver_override);
462 
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)463 static ssize_t modalias_show(struct device *dev,
464 			     struct device_attribute *attr, char *buf)
465 {
466 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
467 	ssize_t len;
468 
469 	len = of_device_modalias(dev, buf, PAGE_SIZE);
470 	if (len != -ENODEV)
471 		return len;
472 
473 	return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name);
474 }
475 static DEVICE_ATTR_RO(modalias);
476 
477 static struct attribute *rpmsg_dev_attrs[] = {
478 	&dev_attr_name.attr,
479 	&dev_attr_modalias.attr,
480 	&dev_attr_dst.attr,
481 	&dev_attr_src.attr,
482 	&dev_attr_announce.attr,
483 	&dev_attr_driver_override.attr,
484 	NULL,
485 };
486 ATTRIBUTE_GROUPS(rpmsg_dev);
487 
488 /* rpmsg devices and drivers are matched using the service name */
rpmsg_id_match(const struct rpmsg_device * rpdev,const struct rpmsg_device_id * id)489 static inline int rpmsg_id_match(const struct rpmsg_device *rpdev,
490 				  const struct rpmsg_device_id *id)
491 {
492 	return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0;
493 }
494 
495 /* match rpmsg channel and rpmsg driver */
rpmsg_dev_match(struct device * dev,const struct device_driver * drv)496 static int rpmsg_dev_match(struct device *dev, const struct device_driver *drv)
497 {
498 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
499 	const struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv);
500 	const struct rpmsg_device_id *ids = rpdrv->id_table;
501 	unsigned int i;
502 
503 	if (rpdev->driver_override)
504 		return !strcmp(rpdev->driver_override, drv->name);
505 
506 	if (ids)
507 		for (i = 0; ids[i].name[0]; i++)
508 			if (rpmsg_id_match(rpdev, &ids[i])) {
509 				rpdev->id.driver_data = ids[i].driver_data;
510 				return 1;
511 			}
512 
513 	return of_driver_match_device(dev, drv);
514 }
515 
rpmsg_uevent(const struct device * dev,struct kobj_uevent_env * env)516 static int rpmsg_uevent(const struct device *dev, struct kobj_uevent_env *env)
517 {
518 	const struct rpmsg_device *rpdev = to_rpmsg_device(dev);
519 	int ret;
520 
521 	ret = of_device_uevent_modalias(dev, env);
522 	if (ret != -ENODEV)
523 		return ret;
524 
525 	return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT,
526 					rpdev->id.name);
527 }
528 
529 /*
530  * when an rpmsg driver is probed with a channel, we seamlessly create
531  * it an endpoint, binding its rx callback to a unique local rpmsg
532  * address.
533  *
534  * if we need to, we also announce about this channel to the remote
535  * processor (needed in case the driver is exposing an rpmsg service).
536  */
rpmsg_dev_probe(struct device * dev)537 static int rpmsg_dev_probe(struct device *dev)
538 {
539 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
540 	struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
541 	struct rpmsg_channel_info chinfo = {};
542 	struct rpmsg_endpoint *ept = NULL;
543 	int err;
544 
545 	err = dev_pm_domain_attach(dev, true);
546 	if (err)
547 		goto out;
548 
549 	if (rpdrv->callback) {
550 		strscpy(chinfo.name, rpdev->id.name, sizeof(chinfo.name));
551 		chinfo.src = rpdev->src;
552 		chinfo.dst = RPMSG_ADDR_ANY;
553 
554 		ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo);
555 		if (!ept) {
556 			dev_err(dev, "failed to create endpoint\n");
557 			err = -ENOMEM;
558 			goto out;
559 		}
560 
561 		rpdev->ept = ept;
562 		rpdev->src = ept->addr;
563 
564 		ept->flow_cb = rpdrv->flowcontrol;
565 	}
566 
567 	err = rpdrv->probe(rpdev);
568 	if (err) {
569 		dev_err(dev, "%s: failed: %d\n", __func__, err);
570 		goto destroy_ept;
571 	}
572 
573 	if (ept && rpdev->ops->announce_create) {
574 		err = rpdev->ops->announce_create(rpdev);
575 		if (err) {
576 			dev_err(dev, "failed to announce creation\n");
577 			goto remove_rpdev;
578 		}
579 	}
580 
581 	return 0;
582 
583 remove_rpdev:
584 	if (rpdrv->remove)
585 		rpdrv->remove(rpdev);
586 destroy_ept:
587 	if (ept)
588 		rpmsg_destroy_ept(ept);
589 out:
590 	return err;
591 }
592 
rpmsg_dev_remove(struct device * dev)593 static void rpmsg_dev_remove(struct device *dev)
594 {
595 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
596 	struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
597 
598 	if (rpdev->ops->announce_destroy)
599 		rpdev->ops->announce_destroy(rpdev);
600 
601 	if (rpdrv->remove)
602 		rpdrv->remove(rpdev);
603 
604 	dev_pm_domain_detach(dev, true);
605 
606 	if (rpdev->ept)
607 		rpmsg_destroy_ept(rpdev->ept);
608 }
609 
610 static const struct bus_type rpmsg_bus = {
611 	.name		= "rpmsg",
612 	.match		= rpmsg_dev_match,
613 	.dev_groups	= rpmsg_dev_groups,
614 	.uevent		= rpmsg_uevent,
615 	.probe		= rpmsg_dev_probe,
616 	.remove		= rpmsg_dev_remove,
617 };
618 
619 /*
620  * A helper for registering rpmsg device with driver override and name.
621  * Drivers should not be using it, but instead rpmsg_register_device().
622  */
rpmsg_register_device_override(struct rpmsg_device * rpdev,const char * driver_override)623 int rpmsg_register_device_override(struct rpmsg_device *rpdev,
624 				   const char *driver_override)
625 {
626 	struct device *dev = &rpdev->dev;
627 	int ret;
628 
629 	if (driver_override)
630 		strscpy_pad(rpdev->id.name, driver_override, RPMSG_NAME_SIZE);
631 
632 	dev_set_name(dev, "%s.%s.%d.%d", dev_name(dev->parent),
633 		     rpdev->id.name, rpdev->src, rpdev->dst);
634 
635 	dev->bus = &rpmsg_bus;
636 
637 	device_initialize(dev);
638 	if (driver_override) {
639 		ret = driver_set_override(dev, &rpdev->driver_override,
640 					  driver_override,
641 					  strlen(driver_override));
642 		if (ret) {
643 			dev_err(dev, "device_set_override failed: %d\n", ret);
644 			put_device(dev);
645 			return ret;
646 		}
647 	}
648 
649 	ret = device_add(dev);
650 	if (ret) {
651 		dev_err(dev, "device_add failed: %d\n", ret);
652 		kfree(rpdev->driver_override);
653 		rpdev->driver_override = NULL;
654 		put_device(dev);
655 	}
656 
657 	return ret;
658 }
659 EXPORT_SYMBOL(rpmsg_register_device_override);
660 
rpmsg_register_device(struct rpmsg_device * rpdev)661 int rpmsg_register_device(struct rpmsg_device *rpdev)
662 {
663 	return rpmsg_register_device_override(rpdev, NULL);
664 }
665 EXPORT_SYMBOL(rpmsg_register_device);
666 
667 /*
668  * find an existing channel using its name + address properties,
669  * and destroy it
670  */
rpmsg_unregister_device(struct device * parent,struct rpmsg_channel_info * chinfo)671 int rpmsg_unregister_device(struct device *parent,
672 			    struct rpmsg_channel_info *chinfo)
673 {
674 	struct device *dev;
675 
676 	dev = rpmsg_find_device(parent, chinfo);
677 	if (!dev)
678 		return -EINVAL;
679 
680 	device_unregister(dev);
681 
682 	put_device(dev);
683 
684 	return 0;
685 }
686 EXPORT_SYMBOL(rpmsg_unregister_device);
687 
688 /**
689  * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus
690  * @rpdrv: pointer to a struct rpmsg_driver
691  * @owner: owning module/driver
692  *
693  * Return: 0 on success, and an appropriate error value on failure.
694  */
__register_rpmsg_driver(struct rpmsg_driver * rpdrv,struct module * owner)695 int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner)
696 {
697 	rpdrv->drv.bus = &rpmsg_bus;
698 	rpdrv->drv.owner = owner;
699 	return driver_register(&rpdrv->drv);
700 }
701 EXPORT_SYMBOL(__register_rpmsg_driver);
702 
703 /**
704  * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus
705  * @rpdrv: pointer to a struct rpmsg_driver
706  *
707  * Return: 0 on success, and an appropriate error value on failure.
708  */
unregister_rpmsg_driver(struct rpmsg_driver * rpdrv)709 void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv)
710 {
711 	driver_unregister(&rpdrv->drv);
712 }
713 EXPORT_SYMBOL(unregister_rpmsg_driver);
714 
715 
rpmsg_init(void)716 static int __init rpmsg_init(void)
717 {
718 	int ret;
719 
720 	ret = class_register(&rpmsg_class);
721 	if (ret) {
722 		pr_err("failed to register rpmsg class\n");
723 		return ret;
724 	}
725 
726 	ret = bus_register(&rpmsg_bus);
727 	if (ret) {
728 		pr_err("failed to register rpmsg bus: %d\n", ret);
729 		class_destroy(&rpmsg_class);
730 	}
731 	return ret;
732 }
733 postcore_initcall(rpmsg_init);
734 
rpmsg_fini(void)735 static void __exit rpmsg_fini(void)
736 {
737 	bus_unregister(&rpmsg_bus);
738 	class_destroy(&rpmsg_class);
739 }
740 module_exit(rpmsg_fini);
741 
742 MODULE_DESCRIPTION("remote processor messaging bus");
743 MODULE_LICENSE("GPL v2");
744