xref: /openbmc/linux/drivers/rpmsg/rpmsg_core.c (revision 8ce49c2a)
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 struct class *rpmsg_class;
24 EXPORT_SYMBOL(rpmsg_class);
25 
26 /**
27  * rpmsg_create_channel() - create a new rpmsg channel
28  * using its name and address info.
29  * @rpdev: rpmsg device
30  * @chinfo: channel_info to bind
31  *
32  * Return: a pointer to the new rpmsg device on success, or NULL on error.
33  */
rpmsg_create_channel(struct rpmsg_device * rpdev,struct rpmsg_channel_info * chinfo)34 struct rpmsg_device *rpmsg_create_channel(struct rpmsg_device *rpdev,
35 					  struct rpmsg_channel_info *chinfo)
36 {
37 	if (WARN_ON(!rpdev))
38 		return NULL;
39 	if (!rpdev->ops || !rpdev->ops->create_channel) {
40 		dev_err(&rpdev->dev, "no create_channel ops found\n");
41 		return NULL;
42 	}
43 
44 	return rpdev->ops->create_channel(rpdev, chinfo);
45 }
46 EXPORT_SYMBOL(rpmsg_create_channel);
47 
48 /**
49  * rpmsg_release_channel() - release a rpmsg channel
50  * using its name and address info.
51  * @rpdev: rpmsg device
52  * @chinfo: channel_info to bind
53  *
54  * Return: 0 on success or an appropriate error value.
55  */
rpmsg_release_channel(struct rpmsg_device * rpdev,struct rpmsg_channel_info * chinfo)56 int rpmsg_release_channel(struct rpmsg_device *rpdev,
57 			  struct rpmsg_channel_info *chinfo)
58 {
59 	if (WARN_ON(!rpdev))
60 		return -EINVAL;
61 	if (!rpdev->ops || !rpdev->ops->release_channel) {
62 		dev_err(&rpdev->dev, "no release_channel ops found\n");
63 		return -ENXIO;
64 	}
65 
66 	return rpdev->ops->release_channel(rpdev, chinfo);
67 }
68 EXPORT_SYMBOL(rpmsg_release_channel);
69 
70 /**
71  * rpmsg_create_ept() - create a new rpmsg_endpoint
72  * @rpdev: rpmsg channel device
73  * @cb: rx callback handler
74  * @priv: private data for the driver's use
75  * @chinfo: channel_info with the local rpmsg address to bind with @cb
76  *
77  * Every rpmsg address in the system is bound to an rx callback (so when
78  * inbound messages arrive, they are dispatched by the rpmsg bus using the
79  * appropriate callback handler) by means of an rpmsg_endpoint struct.
80  *
81  * This function allows drivers to create such an endpoint, and by that,
82  * bind a callback, and possibly some private data too, to an rpmsg address
83  * (either one that is known in advance, or one that will be dynamically
84  * assigned for them).
85  *
86  * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint
87  * is already created for them when they are probed by the rpmsg bus
88  * (using the rx callback provided when they registered to the rpmsg bus).
89  *
90  * So things should just work for simple drivers: they already have an
91  * endpoint, their rx callback is bound to their rpmsg address, and when
92  * relevant inbound messages arrive (i.e. messages which their dst address
93  * equals to the src address of their rpmsg channel), the driver's handler
94  * is invoked to process it.
95  *
96  * That said, more complicated drivers might need to allocate
97  * additional rpmsg addresses, and bind them to different rx callbacks.
98  * To accomplish that, those drivers need to call this function.
99  *
100  * Drivers should provide their @rpdev channel (so the new endpoint would belong
101  * to the same remote processor their channel belongs to), an rx callback
102  * function, an optional private data (which is provided back when the
103  * rx callback is invoked), and an address they want to bind with the
104  * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will
105  * dynamically assign them an available rpmsg address (drivers should have
106  * a very good reason why not to always use RPMSG_ADDR_ANY here).
107  *
108  * Return: a pointer to the endpoint on success, or NULL on error.
109  */
rpmsg_create_ept(struct rpmsg_device * rpdev,rpmsg_rx_cb_t cb,void * priv,struct rpmsg_channel_info chinfo)110 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
111 					rpmsg_rx_cb_t cb, void *priv,
112 					struct rpmsg_channel_info chinfo)
113 {
114 	if (WARN_ON(!rpdev))
115 		return NULL;
116 
117 	return rpdev->ops->create_ept(rpdev, cb, priv, chinfo);
118 }
119 EXPORT_SYMBOL(rpmsg_create_ept);
120 
121 /**
122  * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
123  * @ept: endpoing to destroy
124  *
125  * Should be used by drivers to destroy an rpmsg endpoint previously
126  * created with rpmsg_create_ept(). As with other types of "free" NULL
127  * is a valid parameter.
128  */
rpmsg_destroy_ept(struct rpmsg_endpoint * ept)129 void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
130 {
131 	if (ept && ept->ops)
132 		ept->ops->destroy_ept(ept);
133 }
134 EXPORT_SYMBOL(rpmsg_destroy_ept);
135 
136 /**
137  * rpmsg_send() - send a message across to the remote processor
138  * @ept: the rpmsg endpoint
139  * @data: payload of message
140  * @len: length of payload
141  *
142  * This function sends @data of length @len on the @ept endpoint.
143  * The message will be sent to the remote processor which the @ept
144  * endpoint belongs to, using @ept's address and its associated rpmsg
145  * device destination addresses.
146  * In case there are no TX buffers available, the function will block until
147  * one becomes available, or a timeout of 15 seconds elapses. When the latter
148  * happens, -ERESTARTSYS is returned.
149  *
150  * Can only be called from process context (for now).
151  *
152  * Return: 0 on success and an appropriate error value on failure.
153  */
rpmsg_send(struct rpmsg_endpoint * ept,void * data,int len)154 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
155 {
156 	if (WARN_ON(!ept))
157 		return -EINVAL;
158 	if (!ept->ops->send)
159 		return -ENXIO;
160 
161 	return ept->ops->send(ept, data, len);
162 }
163 EXPORT_SYMBOL(rpmsg_send);
164 
165 /**
166  * rpmsg_sendto() - send a message across to the remote processor, specify dst
167  * @ept: the rpmsg endpoint
168  * @data: payload of message
169  * @len: length of payload
170  * @dst: destination address
171  *
172  * This function sends @data of length @len to the remote @dst address.
173  * The message will be sent to the remote processor which the @ept
174  * endpoint belongs to, using @ept's address as source.
175  * In case there are no TX buffers available, the function will block until
176  * one becomes available, or a timeout of 15 seconds elapses. When the latter
177  * happens, -ERESTARTSYS is returned.
178  *
179  * Can only be called from process context (for now).
180  *
181  * Return: 0 on success and an appropriate error value on failure.
182  */
rpmsg_sendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)183 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
184 {
185 	if (WARN_ON(!ept))
186 		return -EINVAL;
187 	if (!ept->ops->sendto)
188 		return -ENXIO;
189 
190 	return ept->ops->sendto(ept, data, len, dst);
191 }
192 EXPORT_SYMBOL(rpmsg_sendto);
193 
194 /**
195  * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
196  * @ept: the rpmsg endpoint
197  * @src: source address
198  * @dst: destination address
199  * @data: payload of message
200  * @len: length of payload
201  *
202  * This function sends @data of length @len to the remote @dst address,
203  * and uses @src as the source address.
204  * The message will be sent to the remote processor which the @ept
205  * endpoint belongs to.
206  * In case there are no TX buffers available, the function will block until
207  * one becomes available, or a timeout of 15 seconds elapses. When the latter
208  * happens, -ERESTARTSYS is returned.
209  *
210  * Can only be called from process context (for now).
211  *
212  * Return: 0 on success and an appropriate error value on failure.
213  */
rpmsg_send_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)214 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
215 			  void *data, int len)
216 {
217 	if (WARN_ON(!ept))
218 		return -EINVAL;
219 	if (!ept->ops->send_offchannel)
220 		return -ENXIO;
221 
222 	return ept->ops->send_offchannel(ept, src, dst, data, len);
223 }
224 EXPORT_SYMBOL(rpmsg_send_offchannel);
225 
226 /**
227  * rpmsg_trysend() - send a message across to the remote processor
228  * @ept: the rpmsg endpoint
229  * @data: payload of message
230  * @len: length of payload
231  *
232  * This function sends @data of length @len on the @ept endpoint.
233  * The message will be sent to the remote processor which the @ept
234  * endpoint belongs to, using @ept's address as source and its associated
235  * rpdev's address as destination.
236  * In case there are no TX buffers available, the function will immediately
237  * return -ENOMEM without waiting until one becomes available.
238  *
239  * Can only be called from process context (for now).
240  *
241  * Return: 0 on success and an appropriate error value on failure.
242  */
rpmsg_trysend(struct rpmsg_endpoint * ept,void * data,int len)243 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
244 {
245 	if (WARN_ON(!ept))
246 		return -EINVAL;
247 	if (!ept->ops->trysend)
248 		return -ENXIO;
249 
250 	return ept->ops->trysend(ept, data, len);
251 }
252 EXPORT_SYMBOL(rpmsg_trysend);
253 
254 /**
255  * rpmsg_trysendto() - send a message across to the remote processor, specify dst
256  * @ept: the rpmsg endpoint
257  * @data: payload of message
258  * @len: length of payload
259  * @dst: destination address
260  *
261  * This function sends @data of length @len to the remote @dst address.
262  * The message will be sent to the remote processor which the @ept
263  * endpoint belongs to, using @ept's address as source.
264  * In case there are no TX buffers available, the function will immediately
265  * return -ENOMEM without waiting until one becomes available.
266  *
267  * Can only be called from process context (for now).
268  *
269  * Return: 0 on success and an appropriate error value on failure.
270  */
rpmsg_trysendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)271 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
272 {
273 	if (WARN_ON(!ept))
274 		return -EINVAL;
275 	if (!ept->ops->trysendto)
276 		return -ENXIO;
277 
278 	return ept->ops->trysendto(ept, data, len, dst);
279 }
280 EXPORT_SYMBOL(rpmsg_trysendto);
281 
282 /**
283  * rpmsg_poll() - poll the endpoint's send buffers
284  * @ept:	the rpmsg endpoint
285  * @filp:	file for poll_wait()
286  * @wait:	poll_table for poll_wait()
287  *
288  * Return: mask representing the current state of the endpoint's send buffers
289  */
rpmsg_poll(struct rpmsg_endpoint * ept,struct file * filp,poll_table * wait)290 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
291 			poll_table *wait)
292 {
293 	if (WARN_ON(!ept))
294 		return 0;
295 	if (!ept->ops->poll)
296 		return 0;
297 
298 	return ept->ops->poll(ept, filp, wait);
299 }
300 EXPORT_SYMBOL(rpmsg_poll);
301 
302 /**
303  * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
304  * @ept: the rpmsg endpoint
305  * @src: source address
306  * @dst: destination address
307  * @data: payload of message
308  * @len: length of payload
309  *
310  * This function sends @data of length @len to the remote @dst address,
311  * and uses @src as the source address.
312  * The message will be sent to the remote processor which the @ept
313  * endpoint belongs to.
314  * In case there are no TX buffers available, the function will immediately
315  * return -ENOMEM without waiting until one becomes available.
316  *
317  * Can only be called from process context (for now).
318  *
319  * Return: 0 on success and an appropriate error value on failure.
320  */
rpmsg_trysend_offchannel(struct rpmsg_endpoint * ept,u32 src,u32 dst,void * data,int len)321 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
322 			     void *data, int len)
323 {
324 	if (WARN_ON(!ept))
325 		return -EINVAL;
326 	if (!ept->ops->trysend_offchannel)
327 		return -ENXIO;
328 
329 	return ept->ops->trysend_offchannel(ept, src, dst, data, len);
330 }
331 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
332 
333 /**
334  * rpmsg_set_flow_control() - request remote to pause/resume transmission
335  * @ept:	the rpmsg endpoint
336  * @pause:	pause transmission
337  * @dst:	destination address of the endpoint
338  *
339  * Return: 0 on success and an appropriate error value on failure.
340  */
rpmsg_set_flow_control(struct rpmsg_endpoint * ept,bool pause,u32 dst)341 int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
342 {
343 	if (WARN_ON(!ept))
344 		return -EINVAL;
345 	if (!ept->ops->set_flow_control)
346 		return -EOPNOTSUPP;
347 
348 	return ept->ops->set_flow_control(ept, pause, dst);
349 }
350 EXPORT_SYMBOL_GPL(rpmsg_set_flow_control);
351 
352 /**
353  * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
354  * @ept: the rpmsg endpoint
355  *
356  * This function returns maximum buffer size available for a single outgoing message.
357  *
358  * Return: the maximum transmission size on success and an appropriate error
359  * value on failure.
360  */
361 
rpmsg_get_mtu(struct rpmsg_endpoint * ept)362 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
363 {
364 	if (WARN_ON(!ept))
365 		return -EINVAL;
366 	if (!ept->ops->get_mtu)
367 		return -ENOTSUPP;
368 
369 	return ept->ops->get_mtu(ept);
370 }
371 EXPORT_SYMBOL(rpmsg_get_mtu);
372 
373 /*
374  * match a rpmsg channel with a channel info struct.
375  * this is used to make sure we're not creating rpmsg devices for channels
376  * that already exist.
377  */
rpmsg_device_match(struct device * dev,void * data)378 static int rpmsg_device_match(struct device *dev, void *data)
379 {
380 	struct rpmsg_channel_info *chinfo = data;
381 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
382 
383 	if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src)
384 		return 0;
385 
386 	if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst)
387 		return 0;
388 
389 	if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE))
390 		return 0;
391 
392 	/* found a match ! */
393 	return 1;
394 }
395 
rpmsg_find_device(struct device * parent,struct rpmsg_channel_info * chinfo)396 struct device *rpmsg_find_device(struct device *parent,
397 				 struct rpmsg_channel_info *chinfo)
398 {
399 	return device_find_child(parent, chinfo, rpmsg_device_match);
400 
401 }
402 EXPORT_SYMBOL(rpmsg_find_device);
403 
404 /* sysfs show configuration fields */
405 #define rpmsg_show_attr(field, path, format_string)			\
406 static ssize_t								\
407 field##_show(struct device *dev,					\
408 			struct device_attribute *attr, char *buf)	\
409 {									\
410 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
411 									\
412 	return sprintf(buf, format_string, rpdev->path);		\
413 }									\
414 static DEVICE_ATTR_RO(field);
415 
416 #define rpmsg_string_attr(field, member)				\
417 static ssize_t								\
418 field##_store(struct device *dev, struct device_attribute *attr,	\
419 	      const char *buf, size_t sz)				\
420 {									\
421 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
422 	const char *old;						\
423 	char *new;							\
424 									\
425 	new = kstrndup(buf, sz, GFP_KERNEL);				\
426 	if (!new)							\
427 		return -ENOMEM;						\
428 	new[strcspn(new, "\n")] = '\0';					\
429 									\
430 	device_lock(dev);						\
431 	old = rpdev->member;						\
432 	if (strlen(new)) {						\
433 		rpdev->member = new;					\
434 	} else {							\
435 		kfree(new);						\
436 		rpdev->member = NULL;					\
437 	}								\
438 	device_unlock(dev);						\
439 									\
440 	kfree(old);							\
441 									\
442 	return sz;							\
443 }									\
444 static ssize_t								\
445 field##_show(struct device *dev,					\
446 	     struct device_attribute *attr, char *buf)			\
447 {									\
448 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);		\
449 									\
450 	return sprintf(buf, "%s\n", rpdev->member);			\
451 }									\
452 static DEVICE_ATTR_RW(field)
453 
454 /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */
455 rpmsg_show_attr(name, id.name, "%s\n");
456 rpmsg_show_attr(src, src, "0x%x\n");
457 rpmsg_show_attr(dst, dst, "0x%x\n");
458 rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
459 rpmsg_string_attr(driver_override, driver_override);
460 
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)461 static ssize_t modalias_show(struct device *dev,
462 			     struct device_attribute *attr, char *buf)
463 {
464 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
465 	ssize_t len;
466 
467 	len = of_device_modalias(dev, buf, PAGE_SIZE);
468 	if (len != -ENODEV)
469 		return len;
470 
471 	return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name);
472 }
473 static DEVICE_ATTR_RO(modalias);
474 
475 static struct attribute *rpmsg_dev_attrs[] = {
476 	&dev_attr_name.attr,
477 	&dev_attr_modalias.attr,
478 	&dev_attr_dst.attr,
479 	&dev_attr_src.attr,
480 	&dev_attr_announce.attr,
481 	&dev_attr_driver_override.attr,
482 	NULL,
483 };
484 ATTRIBUTE_GROUPS(rpmsg_dev);
485 
486 /* rpmsg devices and drivers are matched using the service name */
rpmsg_id_match(const struct rpmsg_device * rpdev,const struct rpmsg_device_id * id)487 static inline int rpmsg_id_match(const struct rpmsg_device *rpdev,
488 				  const struct rpmsg_device_id *id)
489 {
490 	return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0;
491 }
492 
493 /* match rpmsg channel and rpmsg driver */
rpmsg_dev_match(struct device * dev,struct device_driver * drv)494 static int rpmsg_dev_match(struct device *dev, struct device_driver *drv)
495 {
496 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
497 	struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv);
498 	const struct rpmsg_device_id *ids = rpdrv->id_table;
499 	unsigned int i;
500 
501 	if (rpdev->driver_override)
502 		return !strcmp(rpdev->driver_override, drv->name);
503 
504 	if (ids)
505 		for (i = 0; ids[i].name[0]; i++)
506 			if (rpmsg_id_match(rpdev, &ids[i])) {
507 				rpdev->id.driver_data = ids[i].driver_data;
508 				return 1;
509 			}
510 
511 	return of_driver_match_device(dev, drv);
512 }
513 
rpmsg_uevent(const struct device * dev,struct kobj_uevent_env * env)514 static int rpmsg_uevent(const struct device *dev, struct kobj_uevent_env *env)
515 {
516 	const struct rpmsg_device *rpdev = to_rpmsg_device(dev);
517 	int ret;
518 
519 	ret = of_device_uevent_modalias(dev, env);
520 	if (ret != -ENODEV)
521 		return ret;
522 
523 	return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT,
524 					rpdev->id.name);
525 }
526 
527 /*
528  * when an rpmsg driver is probed with a channel, we seamlessly create
529  * it an endpoint, binding its rx callback to a unique local rpmsg
530  * address.
531  *
532  * if we need to, we also announce about this channel to the remote
533  * processor (needed in case the driver is exposing an rpmsg service).
534  */
rpmsg_dev_probe(struct device * dev)535 static int rpmsg_dev_probe(struct device *dev)
536 {
537 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
538 	struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
539 	struct rpmsg_channel_info chinfo = {};
540 	struct rpmsg_endpoint *ept = NULL;
541 	int err;
542 
543 	err = dev_pm_domain_attach(dev, true);
544 	if (err)
545 		goto out;
546 
547 	if (rpdrv->callback) {
548 		strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
549 		chinfo.src = rpdev->src;
550 		chinfo.dst = RPMSG_ADDR_ANY;
551 
552 		ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo);
553 		if (!ept) {
554 			dev_err(dev, "failed to create endpoint\n");
555 			err = -ENOMEM;
556 			goto out;
557 		}
558 
559 		rpdev->ept = ept;
560 		rpdev->src = ept->addr;
561 
562 		ept->flow_cb = rpdrv->flowcontrol;
563 	}
564 
565 	err = rpdrv->probe(rpdev);
566 	if (err) {
567 		dev_err(dev, "%s: failed: %d\n", __func__, err);
568 		goto destroy_ept;
569 	}
570 
571 	if (ept && rpdev->ops->announce_create) {
572 		err = rpdev->ops->announce_create(rpdev);
573 		if (err) {
574 			dev_err(dev, "failed to announce creation\n");
575 			goto remove_rpdev;
576 		}
577 	}
578 
579 	return 0;
580 
581 remove_rpdev:
582 	if (rpdrv->remove)
583 		rpdrv->remove(rpdev);
584 destroy_ept:
585 	if (ept)
586 		rpmsg_destroy_ept(ept);
587 out:
588 	return err;
589 }
590 
rpmsg_dev_remove(struct device * dev)591 static void rpmsg_dev_remove(struct device *dev)
592 {
593 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
594 	struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
595 
596 	if (rpdev->ops->announce_destroy)
597 		rpdev->ops->announce_destroy(rpdev);
598 
599 	if (rpdrv->remove)
600 		rpdrv->remove(rpdev);
601 
602 	dev_pm_domain_detach(dev, true);
603 
604 	if (rpdev->ept)
605 		rpmsg_destroy_ept(rpdev->ept);
606 }
607 
608 static struct bus_type rpmsg_bus = {
609 	.name		= "rpmsg",
610 	.match		= rpmsg_dev_match,
611 	.dev_groups	= rpmsg_dev_groups,
612 	.uevent		= rpmsg_uevent,
613 	.probe		= rpmsg_dev_probe,
614 	.remove		= rpmsg_dev_remove,
615 };
616 
617 /*
618  * A helper for registering rpmsg device with driver override and name.
619  * Drivers should not be using it, but instead rpmsg_register_device().
620  */
rpmsg_register_device_override(struct rpmsg_device * rpdev,const char * driver_override)621 int rpmsg_register_device_override(struct rpmsg_device *rpdev,
622 				   const char *driver_override)
623 {
624 	struct device *dev = &rpdev->dev;
625 	int ret;
626 
627 	if (driver_override)
628 		strscpy_pad(rpdev->id.name, driver_override, RPMSG_NAME_SIZE);
629 
630 	dev_set_name(dev, "%s.%s.%d.%d", dev_name(dev->parent),
631 		     rpdev->id.name, rpdev->src, rpdev->dst);
632 
633 	dev->bus = &rpmsg_bus;
634 
635 	device_initialize(dev);
636 	if (driver_override) {
637 		ret = driver_set_override(dev, &rpdev->driver_override,
638 					  driver_override,
639 					  strlen(driver_override));
640 		if (ret) {
641 			dev_err(dev, "device_set_override failed: %d\n", ret);
642 			put_device(dev);
643 			return ret;
644 		}
645 	}
646 
647 	ret = device_add(dev);
648 	if (ret) {
649 		dev_err(dev, "device_add failed: %d\n", ret);
650 		kfree(rpdev->driver_override);
651 		rpdev->driver_override = NULL;
652 		put_device(dev);
653 	}
654 
655 	return ret;
656 }
657 EXPORT_SYMBOL(rpmsg_register_device_override);
658 
rpmsg_register_device(struct rpmsg_device * rpdev)659 int rpmsg_register_device(struct rpmsg_device *rpdev)
660 {
661 	return rpmsg_register_device_override(rpdev, NULL);
662 }
663 EXPORT_SYMBOL(rpmsg_register_device);
664 
665 /*
666  * find an existing channel using its name + address properties,
667  * and destroy it
668  */
rpmsg_unregister_device(struct device * parent,struct rpmsg_channel_info * chinfo)669 int rpmsg_unregister_device(struct device *parent,
670 			    struct rpmsg_channel_info *chinfo)
671 {
672 	struct device *dev;
673 
674 	dev = rpmsg_find_device(parent, chinfo);
675 	if (!dev)
676 		return -EINVAL;
677 
678 	device_unregister(dev);
679 
680 	put_device(dev);
681 
682 	return 0;
683 }
684 EXPORT_SYMBOL(rpmsg_unregister_device);
685 
686 /**
687  * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus
688  * @rpdrv: pointer to a struct rpmsg_driver
689  * @owner: owning module/driver
690  *
691  * Return: 0 on success, and an appropriate error value on failure.
692  */
__register_rpmsg_driver(struct rpmsg_driver * rpdrv,struct module * owner)693 int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner)
694 {
695 	rpdrv->drv.bus = &rpmsg_bus;
696 	rpdrv->drv.owner = owner;
697 	return driver_register(&rpdrv->drv);
698 }
699 EXPORT_SYMBOL(__register_rpmsg_driver);
700 
701 /**
702  * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus
703  * @rpdrv: pointer to a struct rpmsg_driver
704  *
705  * Return: 0 on success, and an appropriate error value on failure.
706  */
unregister_rpmsg_driver(struct rpmsg_driver * rpdrv)707 void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv)
708 {
709 	driver_unregister(&rpdrv->drv);
710 }
711 EXPORT_SYMBOL(unregister_rpmsg_driver);
712 
713 
rpmsg_init(void)714 static int __init rpmsg_init(void)
715 {
716 	int ret;
717 
718 	rpmsg_class = class_create("rpmsg");
719 	if (IS_ERR(rpmsg_class)) {
720 		pr_err("failed to create rpmsg class\n");
721 		return PTR_ERR(rpmsg_class);
722 	}
723 
724 	ret = bus_register(&rpmsg_bus);
725 	if (ret) {
726 		pr_err("failed to register rpmsg bus: %d\n", ret);
727 		class_destroy(rpmsg_class);
728 	}
729 	return ret;
730 }
731 postcore_initcall(rpmsg_init);
732 
rpmsg_fini(void)733 static void __exit rpmsg_fini(void)
734 {
735 	bus_unregister(&rpmsg_bus);
736 	class_destroy(rpmsg_class);
737 }
738 module_exit(rpmsg_fini);
739 
740 MODULE_DESCRIPTION("remote processor messaging bus");
741 MODULE_LICENSE("GPL v2");
742