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026dad47 BA |
1 | /* |
2 | * remote processor messaging bus | |
3 | * | |
4 | * Copyright (C) 2011 Texas Instruments, Inc. | |
5 | * Copyright (C) 2011 Google, Inc. | |
6 | * | |
7 | * Ohad Ben-Cohen <ohad@wizery.com> | |
8 | * Brian Swetland <swetland@google.com> | |
9 | * | |
10 | * This software is licensed under the terms of the GNU General Public | |
11 | * License version 2, as published by the Free Software Foundation, and | |
12 | * may be copied, distributed, and modified under those terms. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #define pr_fmt(fmt) "%s: " fmt, __func__ | |
21 | ||
22 | #include <linux/kernel.h> | |
fade037e | 23 | #include <linux/module.h> |
026dad47 | 24 | #include <linux/rpmsg.h> |
fade037e BA |
25 | #include <linux/of_device.h> |
26 | #include <linux/slab.h> | |
026dad47 | 27 | |
8b881c07 BA |
28 | #include "rpmsg_internal.h" |
29 | ||
026dad47 BA |
30 | /** |
31 | * rpmsg_create_ept() - create a new rpmsg_endpoint | |
32 | * @rpdev: rpmsg channel device | |
33 | * @cb: rx callback handler | |
34 | * @priv: private data for the driver's use | |
35 | * @chinfo: channel_info with the local rpmsg address to bind with @cb | |
36 | * | |
37 | * Every rpmsg address in the system is bound to an rx callback (so when | |
38 | * inbound messages arrive, they are dispatched by the rpmsg bus using the | |
39 | * appropriate callback handler) by means of an rpmsg_endpoint struct. | |
40 | * | |
41 | * This function allows drivers to create such an endpoint, and by that, | |
42 | * bind a callback, and possibly some private data too, to an rpmsg address | |
43 | * (either one that is known in advance, or one that will be dynamically | |
44 | * assigned for them). | |
45 | * | |
46 | * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint | |
47 | * is already created for them when they are probed by the rpmsg bus | |
48 | * (using the rx callback provided when they registered to the rpmsg bus). | |
49 | * | |
50 | * So things should just work for simple drivers: they already have an | |
51 | * endpoint, their rx callback is bound to their rpmsg address, and when | |
52 | * relevant inbound messages arrive (i.e. messages which their dst address | |
53 | * equals to the src address of their rpmsg channel), the driver's handler | |
54 | * is invoked to process it. | |
55 | * | |
56 | * That said, more complicated drivers might do need to allocate | |
57 | * additional rpmsg addresses, and bind them to different rx callbacks. | |
58 | * To accomplish that, those drivers need to call this function. | |
59 | * | |
60 | * Drivers should provide their @rpdev channel (so the new endpoint would belong | |
61 | * to the same remote processor their channel belongs to), an rx callback | |
62 | * function, an optional private data (which is provided back when the | |
63 | * rx callback is invoked), and an address they want to bind with the | |
64 | * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will | |
65 | * dynamically assign them an available rpmsg address (drivers should have | |
66 | * a very good reason why not to always use RPMSG_ADDR_ANY here). | |
67 | * | |
68 | * Returns a pointer to the endpoint on success, or NULL on error. | |
69 | */ | |
70 | struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, | |
71 | rpmsg_rx_cb_t cb, void *priv, | |
72 | struct rpmsg_channel_info chinfo) | |
73 | { | |
74 | return rpdev->ops->create_ept(rpdev, cb, priv, chinfo); | |
75 | } | |
76 | EXPORT_SYMBOL(rpmsg_create_ept); | |
c9bd6f42 BA |
77 | |
78 | /** | |
79 | * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint | |
80 | * @ept: endpoing to destroy | |
81 | * | |
82 | * Should be used by drivers to destroy an rpmsg endpoint previously | |
83 | * created with rpmsg_create_ept(). | |
84 | */ | |
85 | void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) | |
86 | { | |
87 | ept->ops->destroy_ept(ept); | |
88 | } | |
89 | EXPORT_SYMBOL(rpmsg_destroy_ept); | |
90 | ||
91 | /** | |
92 | * rpmsg_send() - send a message across to the remote processor | |
93 | * @ept: the rpmsg endpoint | |
94 | * @data: payload of message | |
95 | * @len: length of payload | |
96 | * | |
97 | * This function sends @data of length @len on the @ept endpoint. | |
98 | * The message will be sent to the remote processor which the @ept | |
99 | * endpoint belongs to, using @ept's address and its associated rpmsg | |
100 | * device destination addresses. | |
101 | * In case there are no TX buffers available, the function will block until | |
102 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
103 | * happens, -ERESTARTSYS is returned. | |
104 | * | |
105 | * Can only be called from process context (for now). | |
106 | * | |
107 | * Returns 0 on success and an appropriate error value on failure. | |
108 | */ | |
109 | int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) | |
110 | { | |
111 | return ept->ops->send(ept, data, len); | |
112 | } | |
113 | EXPORT_SYMBOL(rpmsg_send); | |
114 | ||
115 | /** | |
116 | * rpmsg_sendto() - send a message across to the remote processor, specify dst | |
117 | * @ept: the rpmsg endpoint | |
118 | * @data: payload of message | |
119 | * @len: length of payload | |
120 | * @dst: destination address | |
121 | * | |
122 | * This function sends @data of length @len to the remote @dst address. | |
123 | * The message will be sent to the remote processor which the @ept | |
124 | * endpoint belongs to, using @ept's address as source. | |
125 | * In case there are no TX buffers available, the function will block until | |
126 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
127 | * happens, -ERESTARTSYS is returned. | |
128 | * | |
129 | * Can only be called from process context (for now). | |
130 | * | |
131 | * Returns 0 on success and an appropriate error value on failure. | |
132 | */ | |
133 | int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) | |
134 | { | |
135 | return ept->ops->sendto(ept, data, len, dst); | |
136 | } | |
137 | EXPORT_SYMBOL(rpmsg_sendto); | |
138 | ||
139 | /** | |
140 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | |
141 | * @ept: the rpmsg endpoint | |
142 | * @src: source address | |
143 | * @dst: destination address | |
144 | * @data: payload of message | |
145 | * @len: length of payload | |
146 | * | |
147 | * This function sends @data of length @len to the remote @dst address, | |
148 | * and uses @src as the source address. | |
149 | * The message will be sent to the remote processor which the @ept | |
150 | * endpoint belongs to. | |
151 | * In case there are no TX buffers available, the function will block until | |
152 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
153 | * happens, -ERESTARTSYS is returned. | |
154 | * | |
155 | * Can only be called from process context (for now). | |
156 | * | |
157 | * Returns 0 on success and an appropriate error value on failure. | |
158 | */ | |
159 | int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, | |
160 | void *data, int len) | |
161 | { | |
162 | return ept->ops->send_offchannel(ept, src, dst, data, len); | |
163 | } | |
164 | EXPORT_SYMBOL(rpmsg_send_offchannel); | |
165 | ||
166 | /** | |
167 | * rpmsg_send() - send a message across to the remote processor | |
168 | * @ept: the rpmsg endpoint | |
169 | * @data: payload of message | |
170 | * @len: length of payload | |
171 | * | |
172 | * This function sends @data of length @len on the @ept endpoint. | |
173 | * The message will be sent to the remote processor which the @ept | |
174 | * endpoint belongs to, using @ept's address as source and its associated | |
175 | * rpdev's address as destination. | |
176 | * In case there are no TX buffers available, the function will immediately | |
177 | * return -ENOMEM without waiting until one becomes available. | |
178 | * | |
179 | * Can only be called from process context (for now). | |
180 | * | |
181 | * Returns 0 on success and an appropriate error value on failure. | |
182 | */ | |
183 | int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) | |
184 | { | |
185 | return ept->ops->trysend(ept, data, len); | |
186 | } | |
187 | EXPORT_SYMBOL(rpmsg_trysend); | |
188 | ||
189 | /** | |
190 | * rpmsg_sendto() - send a message across to the remote processor, specify dst | |
191 | * @ept: the rpmsg endpoint | |
192 | * @data: payload of message | |
193 | * @len: length of payload | |
194 | * @dst: destination address | |
195 | * | |
196 | * This function sends @data of length @len to the remote @dst address. | |
197 | * The message will be sent to the remote processor which the @ept | |
198 | * endpoint belongs to, using @ept's address as source. | |
199 | * In case there are no TX buffers available, the function will immediately | |
200 | * return -ENOMEM without waiting until one becomes available. | |
201 | * | |
202 | * Can only be called from process context (for now). | |
203 | * | |
204 | * Returns 0 on success and an appropriate error value on failure. | |
205 | */ | |
206 | int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) | |
207 | { | |
208 | return ept->ops->trysendto(ept, data, len, dst); | |
209 | } | |
210 | EXPORT_SYMBOL(rpmsg_trysendto); | |
211 | ||
212 | /** | |
213 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | |
214 | * @ept: the rpmsg endpoint | |
215 | * @src: source address | |
216 | * @dst: destination address | |
217 | * @data: payload of message | |
218 | * @len: length of payload | |
219 | * | |
220 | * This function sends @data of length @len to the remote @dst address, | |
221 | * and uses @src as the source address. | |
222 | * The message will be sent to the remote processor which the @ept | |
223 | * endpoint belongs to. | |
224 | * In case there are no TX buffers available, the function will immediately | |
225 | * return -ENOMEM without waiting until one becomes available. | |
226 | * | |
227 | * Can only be called from process context (for now). | |
228 | * | |
229 | * Returns 0 on success and an appropriate error value on failure. | |
230 | */ | |
231 | int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, | |
232 | void *data, int len) | |
233 | { | |
234 | return ept->ops->trysend_offchannel(ept, src, dst, data, len); | |
235 | } | |
236 | EXPORT_SYMBOL(rpmsg_trysend_offchannel); | |
8b881c07 BA |
237 | |
238 | /* | |
239 | * match an rpmsg channel with a channel info struct. | |
240 | * this is used to make sure we're not creating rpmsg devices for channels | |
241 | * that already exist. | |
242 | */ | |
243 | static int rpmsg_device_match(struct device *dev, void *data) | |
244 | { | |
245 | struct rpmsg_channel_info *chinfo = data; | |
246 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
247 | ||
248 | if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) | |
249 | return 0; | |
250 | ||
251 | if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) | |
252 | return 0; | |
253 | ||
254 | if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) | |
255 | return 0; | |
256 | ||
257 | /* found a match ! */ | |
258 | return 1; | |
259 | } | |
260 | ||
261 | struct device *rpmsg_find_device(struct device *parent, | |
262 | struct rpmsg_channel_info *chinfo) | |
263 | { | |
264 | return device_find_child(parent, chinfo, rpmsg_device_match); | |
265 | ||
266 | } | |
267 | EXPORT_SYMBOL(rpmsg_find_device); | |
5e619b48 BA |
268 | |
269 | /* sysfs show configuration fields */ | |
270 | #define rpmsg_show_attr(field, path, format_string) \ | |
271 | static ssize_t \ | |
272 | field##_show(struct device *dev, \ | |
273 | struct device_attribute *attr, char *buf) \ | |
274 | { \ | |
275 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ | |
276 | \ | |
277 | return sprintf(buf, format_string, rpdev->path); \ | |
278 | } | |
279 | ||
280 | /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */ | |
281 | rpmsg_show_attr(name, id.name, "%s\n"); | |
282 | rpmsg_show_attr(src, src, "0x%x\n"); | |
283 | rpmsg_show_attr(dst, dst, "0x%x\n"); | |
284 | rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); | |
285 | ||
286 | static ssize_t modalias_show(struct device *dev, | |
287 | struct device_attribute *attr, char *buf) | |
288 | { | |
289 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
290 | ||
291 | return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name); | |
292 | } | |
293 | ||
294 | static struct device_attribute rpmsg_dev_attrs[] = { | |
295 | __ATTR_RO(name), | |
296 | __ATTR_RO(modalias), | |
297 | __ATTR_RO(dst), | |
298 | __ATTR_RO(src), | |
299 | __ATTR_RO(announce), | |
300 | __ATTR_NULL | |
301 | }; | |
302 | ||
303 | /* rpmsg devices and drivers are matched using the service name */ | |
304 | static inline int rpmsg_id_match(const struct rpmsg_device *rpdev, | |
305 | const struct rpmsg_device_id *id) | |
306 | { | |
307 | return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0; | |
308 | } | |
309 | ||
310 | /* match rpmsg channel and rpmsg driver */ | |
311 | static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) | |
312 | { | |
313 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
314 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv); | |
315 | const struct rpmsg_device_id *ids = rpdrv->id_table; | |
316 | unsigned int i; | |
317 | ||
318 | if (ids) | |
319 | for (i = 0; ids[i].name[0]; i++) | |
320 | if (rpmsg_id_match(rpdev, &ids[i])) | |
321 | return 1; | |
322 | ||
323 | return of_driver_match_device(dev, drv); | |
324 | } | |
325 | ||
326 | static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) | |
327 | { | |
328 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
329 | ||
330 | return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT, | |
331 | rpdev->id.name); | |
332 | } | |
333 | ||
334 | /* | |
335 | * when an rpmsg driver is probed with a channel, we seamlessly create | |
336 | * it an endpoint, binding its rx callback to a unique local rpmsg | |
337 | * address. | |
338 | * | |
339 | * if we need to, we also announce about this channel to the remote | |
340 | * processor (needed in case the driver is exposing an rpmsg service). | |
341 | */ | |
342 | static int rpmsg_dev_probe(struct device *dev) | |
343 | { | |
344 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
345 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); | |
346 | struct rpmsg_channel_info chinfo = {}; | |
347 | struct rpmsg_endpoint *ept; | |
348 | int err; | |
349 | ||
350 | strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); | |
351 | chinfo.src = rpdev->src; | |
352 | chinfo.dst = RPMSG_ADDR_ANY; | |
353 | ||
354 | ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo); | |
355 | if (!ept) { | |
356 | dev_err(dev, "failed to create endpoint\n"); | |
357 | err = -ENOMEM; | |
358 | goto out; | |
359 | } | |
360 | ||
361 | rpdev->ept = ept; | |
362 | rpdev->src = ept->addr; | |
363 | ||
364 | err = rpdrv->probe(rpdev); | |
365 | if (err) { | |
366 | dev_err(dev, "%s: failed: %d\n", __func__, err); | |
367 | rpmsg_destroy_ept(ept); | |
368 | goto out; | |
369 | } | |
370 | ||
371 | if (rpdev->ops->announce_create) | |
372 | err = rpdev->ops->announce_create(rpdev); | |
373 | out: | |
374 | return err; | |
375 | } | |
376 | ||
377 | static int rpmsg_dev_remove(struct device *dev) | |
378 | { | |
379 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
380 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); | |
381 | int err = 0; | |
382 | ||
383 | if (rpdev->ops->announce_destroy) | |
384 | err = rpdev->ops->announce_destroy(rpdev); | |
385 | ||
386 | rpdrv->remove(rpdev); | |
387 | ||
388 | rpmsg_destroy_ept(rpdev->ept); | |
389 | ||
390 | return err; | |
391 | } | |
392 | ||
393 | static struct bus_type rpmsg_bus = { | |
394 | .name = "rpmsg", | |
395 | .match = rpmsg_dev_match, | |
396 | .dev_attrs = rpmsg_dev_attrs, | |
397 | .uevent = rpmsg_uevent, | |
398 | .probe = rpmsg_dev_probe, | |
399 | .remove = rpmsg_dev_remove, | |
400 | }; | |
401 | ||
402 | static void rpmsg_release_device(struct device *dev) | |
403 | { | |
404 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
405 | ||
406 | kfree(rpdev); | |
407 | } | |
408 | ||
409 | int rpmsg_register_device(struct rpmsg_device *rpdev) | |
410 | { | |
411 | struct device *dev = &rpdev->dev; | |
412 | int ret; | |
413 | ||
414 | dev_set_name(&rpdev->dev, "%s:%s", | |
415 | dev_name(dev->parent), rpdev->id.name); | |
416 | ||
417 | rpdev->dev.bus = &rpmsg_bus; | |
418 | rpdev->dev.release = rpmsg_release_device; | |
419 | ||
420 | ret = device_register(&rpdev->dev); | |
421 | if (ret) { | |
422 | dev_err(dev, "device_register failed: %d\n", ret); | |
423 | put_device(&rpdev->dev); | |
424 | } | |
425 | ||
426 | return ret; | |
427 | } | |
428 | EXPORT_SYMBOL(rpmsg_register_device); | |
429 | ||
430 | /* | |
431 | * find an existing channel using its name + address properties, | |
432 | * and destroy it | |
433 | */ | |
434 | int rpmsg_unregister_device(struct device *parent, | |
435 | struct rpmsg_channel_info *chinfo) | |
436 | { | |
437 | struct device *dev; | |
438 | ||
439 | dev = rpmsg_find_device(parent, chinfo); | |
440 | if (!dev) | |
441 | return -EINVAL; | |
442 | ||
443 | device_unregister(dev); | |
444 | ||
445 | put_device(dev); | |
446 | ||
447 | return 0; | |
448 | } | |
449 | EXPORT_SYMBOL(rpmsg_unregister_device); | |
450 | ||
451 | /** | |
452 | * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus | |
453 | * @rpdrv: pointer to a struct rpmsg_driver | |
454 | * @owner: owning module/driver | |
455 | * | |
456 | * Returns 0 on success, and an appropriate error value on failure. | |
457 | */ | |
458 | int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner) | |
459 | { | |
460 | rpdrv->drv.bus = &rpmsg_bus; | |
461 | rpdrv->drv.owner = owner; | |
462 | return driver_register(&rpdrv->drv); | |
463 | } | |
464 | EXPORT_SYMBOL(__register_rpmsg_driver); | |
465 | ||
466 | /** | |
467 | * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus | |
468 | * @rpdrv: pointer to a struct rpmsg_driver | |
469 | * | |
470 | * Returns 0 on success, and an appropriate error value on failure. | |
471 | */ | |
472 | void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv) | |
473 | { | |
474 | driver_unregister(&rpdrv->drv); | |
475 | } | |
476 | EXPORT_SYMBOL(unregister_rpmsg_driver); | |
477 | ||
478 | ||
479 | static int __init rpmsg_init(void) | |
480 | { | |
481 | int ret; | |
482 | ||
483 | ret = bus_register(&rpmsg_bus); | |
484 | if (ret) | |
485 | pr_err("failed to register rpmsg bus: %d\n", ret); | |
486 | ||
487 | return ret; | |
488 | } | |
489 | postcore_initcall(rpmsg_init); | |
490 | ||
491 | static void __exit rpmsg_fini(void) | |
492 | { | |
493 | bus_unregister(&rpmsg_bus); | |
494 | } | |
495 | module_exit(rpmsg_fini); | |
496 | ||
497 | MODULE_DESCRIPTION("remote processor messaging bus"); | |
498 | MODULE_LICENSE("GPL v2"); |