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bcabbcca OBC |
1 | /* |
2 | * Remote processor messaging | |
3 | * | |
4 | * Copyright (C) 2011 Texas Instruments, Inc. | |
5 | * Copyright (C) 2011 Google, Inc. | |
6 | * All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * | |
12 | * * Redistributions of source code must retain the above copyright | |
13 | * notice, this list of conditions and the following disclaimer. | |
14 | * * Redistributions in binary form must reproduce the above copyright | |
15 | * notice, this list of conditions and the following disclaimer in | |
16 | * the documentation and/or other materials provided with the | |
17 | * distribution. | |
18 | * * Neither the name Texas Instruments nor the names of its | |
19 | * contributors may be used to endorse or promote products derived | |
20 | * from this software without specific prior written permission. | |
21 | * | |
22 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
23 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
24 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
25 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
26 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
27 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
28 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
29 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
30 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
31 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
32 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
33 | */ | |
34 | ||
35 | #ifndef _LINUX_RPMSG_H | |
36 | #define _LINUX_RPMSG_H | |
37 | ||
38 | #include <linux/types.h> | |
39 | #include <linux/device.h> | |
40 | #include <linux/mod_devicetable.h> | |
5a081caa | 41 | #include <linux/kref.h> |
15fd943a | 42 | #include <linux/mutex.h> |
bcabbcca OBC |
43 | |
44 | /* The feature bitmap for virtio rpmsg */ | |
45 | #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ | |
46 | ||
47 | /** | |
48 | * struct rpmsg_hdr - common header for all rpmsg messages | |
49 | * @src: source address | |
50 | * @dst: destination address | |
51 | * @reserved: reserved for future use | |
52 | * @len: length of payload (in bytes) | |
53 | * @flags: message flags | |
54 | * @data: @len bytes of message payload data | |
55 | * | |
56 | * Every message sent(/received) on the rpmsg bus begins with this header. | |
57 | */ | |
58 | struct rpmsg_hdr { | |
59 | u32 src; | |
60 | u32 dst; | |
61 | u32 reserved; | |
62 | u16 len; | |
63 | u16 flags; | |
64 | u8 data[0]; | |
65 | } __packed; | |
66 | ||
67 | /** | |
68 | * struct rpmsg_ns_msg - dynamic name service announcement message | |
69 | * @name: name of remote service that is published | |
70 | * @addr: address of remote service that is published | |
71 | * @flags: indicates whether service is created or destroyed | |
72 | * | |
73 | * This message is sent across to publish a new service, or announce | |
74 | * about its removal. When we receive these messages, an appropriate | |
75 | * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe() | |
76 | * or ->remove() handler of the appropriate rpmsg driver will be invoked | |
77 | * (if/as-soon-as one is registered). | |
78 | */ | |
79 | struct rpmsg_ns_msg { | |
80 | char name[RPMSG_NAME_SIZE]; | |
81 | u32 addr; | |
82 | u32 flags; | |
83 | } __packed; | |
84 | ||
85 | /** | |
86 | * enum rpmsg_ns_flags - dynamic name service announcement flags | |
87 | * | |
88 | * @RPMSG_NS_CREATE: a new remote service was just created | |
89 | * @RPMSG_NS_DESTROY: a known remote service was just destroyed | |
90 | */ | |
91 | enum rpmsg_ns_flags { | |
92 | RPMSG_NS_CREATE = 0, | |
93 | RPMSG_NS_DESTROY = 1, | |
94 | }; | |
95 | ||
96 | #define RPMSG_ADDR_ANY 0xFFFFFFFF | |
97 | ||
98 | struct virtproc_info; | |
99 | ||
100 | /** | |
101 | * rpmsg_channel - devices that belong to the rpmsg bus are called channels | |
102 | * @vrp: the remote processor this channel belongs to | |
103 | * @dev: the device struct | |
104 | * @id: device id (used to match between rpmsg drivers and devices) | |
105 | * @src: local address | |
106 | * @dst: destination address | |
107 | * @ept: the rpmsg endpoint of this channel | |
108 | * @announce: if set, rpmsg will announce the creation/removal of this channel | |
109 | */ | |
110 | struct rpmsg_channel { | |
111 | struct virtproc_info *vrp; | |
112 | struct device dev; | |
113 | struct rpmsg_device_id id; | |
114 | u32 src; | |
115 | u32 dst; | |
116 | struct rpmsg_endpoint *ept; | |
117 | bool announce; | |
118 | }; | |
119 | ||
120 | typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32); | |
121 | ||
122 | /** | |
123 | * struct rpmsg_endpoint - binds a local rpmsg address to its user | |
124 | * @rpdev: rpmsg channel device | |
5a081caa | 125 | * @refcount: when this drops to zero, the ept is deallocated |
bcabbcca | 126 | * @cb: rx callback handler |
15fd943a | 127 | * @cb_lock: must be taken before accessing/changing @cb |
bcabbcca OBC |
128 | * @addr: local rpmsg address |
129 | * @priv: private data for the driver's use | |
130 | * | |
131 | * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as | |
132 | * it binds an rpmsg address with an rx callback handler. | |
133 | * | |
134 | * Simple rpmsg drivers shouldn't use this struct directly, because | |
135 | * things just work: every rpmsg driver provides an rx callback upon | |
136 | * registering to the bus, and that callback is then bound to its rpmsg | |
137 | * address when the driver is probed. When relevant inbound messages arrive | |
138 | * (i.e. messages which their dst address equals to the src address of | |
139 | * the rpmsg channel), the driver's handler is invoked to process it. | |
140 | * | |
141 | * More complicated drivers though, that do need to allocate additional rpmsg | |
142 | * addresses, and bind them to different rx callbacks, must explicitly | |
143 | * create additional endpoints by themselves (see rpmsg_create_ept()). | |
144 | */ | |
145 | struct rpmsg_endpoint { | |
146 | struct rpmsg_channel *rpdev; | |
5a081caa | 147 | struct kref refcount; |
bcabbcca | 148 | rpmsg_rx_cb_t cb; |
15fd943a | 149 | struct mutex cb_lock; |
bcabbcca OBC |
150 | u32 addr; |
151 | void *priv; | |
152 | }; | |
153 | ||
154 | /** | |
155 | * struct rpmsg_driver - rpmsg driver struct | |
156 | * @drv: underlying device driver | |
157 | * @id_table: rpmsg ids serviced by this driver | |
158 | * @probe: invoked when a matching rpmsg channel (i.e. device) is found | |
159 | * @remove: invoked when the rpmsg channel is removed | |
160 | * @callback: invoked when an inbound message is received on the channel | |
161 | */ | |
162 | struct rpmsg_driver { | |
163 | struct device_driver drv; | |
164 | const struct rpmsg_device_id *id_table; | |
165 | int (*probe)(struct rpmsg_channel *dev); | |
166 | void (*remove)(struct rpmsg_channel *dev); | |
167 | void (*callback)(struct rpmsg_channel *, void *, int, void *, u32); | |
168 | }; | |
169 | ||
170 | int register_rpmsg_device(struct rpmsg_channel *dev); | |
171 | void unregister_rpmsg_device(struct rpmsg_channel *dev); | |
172 | int register_rpmsg_driver(struct rpmsg_driver *drv); | |
173 | void unregister_rpmsg_driver(struct rpmsg_driver *drv); | |
174 | void rpmsg_destroy_ept(struct rpmsg_endpoint *); | |
175 | struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *, | |
176 | rpmsg_rx_cb_t cb, void *priv, u32 addr); | |
177 | int | |
178 | rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool); | |
179 | ||
180 | /** | |
181 | * rpmsg_send() - send a message across to the remote processor | |
182 | * @rpdev: the rpmsg channel | |
183 | * @data: payload of message | |
184 | * @len: length of payload | |
185 | * | |
186 | * This function sends @data of length @len on the @rpdev channel. | |
187 | * The message will be sent to the remote processor which the @rpdev | |
188 | * channel belongs to, using @rpdev's source and destination addresses. | |
189 | * In case there are no TX buffers available, the function will block until | |
190 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
191 | * happens, -ERESTARTSYS is returned. | |
192 | * | |
193 | * Can only be called from process context (for now). | |
194 | * | |
195 | * Returns 0 on success and an appropriate error value on failure. | |
196 | */ | |
197 | static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len) | |
198 | { | |
199 | u32 src = rpdev->src, dst = rpdev->dst; | |
200 | ||
201 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
202 | } | |
203 | ||
204 | /** | |
205 | * rpmsg_sendto() - send a message across to the remote processor, specify dst | |
206 | * @rpdev: the rpmsg channel | |
207 | * @data: payload of message | |
208 | * @len: length of payload | |
209 | * @dst: destination address | |
210 | * | |
211 | * This function sends @data of length @len to the remote @dst address. | |
212 | * The message will be sent to the remote processor which the @rpdev | |
213 | * channel belongs to, using @rpdev's source address. | |
214 | * In case there are no TX buffers available, the function will block until | |
215 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
216 | * happens, -ERESTARTSYS is returned. | |
217 | * | |
218 | * Can only be called from process context (for now). | |
219 | * | |
220 | * Returns 0 on success and an appropriate error value on failure. | |
221 | */ | |
222 | static inline | |
223 | int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) | |
224 | { | |
225 | u32 src = rpdev->src; | |
226 | ||
227 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
228 | } | |
229 | ||
230 | /** | |
231 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | |
232 | * @rpdev: the rpmsg channel | |
233 | * @src: source address | |
234 | * @dst: destination address | |
235 | * @data: payload of message | |
236 | * @len: length of payload | |
237 | * | |
238 | * This function sends @data of length @len to the remote @dst address, | |
239 | * and uses @src as the source address. | |
240 | * The message will be sent to the remote processor which the @rpdev | |
241 | * channel belongs to. | |
242 | * In case there are no TX buffers available, the function will block until | |
243 | * one becomes available, or a timeout of 15 seconds elapses. When the latter | |
244 | * happens, -ERESTARTSYS is returned. | |
245 | * | |
246 | * Can only be called from process context (for now). | |
247 | * | |
248 | * Returns 0 on success and an appropriate error value on failure. | |
249 | */ | |
250 | static inline | |
251 | int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, | |
252 | void *data, int len) | |
253 | { | |
254 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
255 | } | |
256 | ||
257 | /** | |
258 | * rpmsg_send() - send a message across to the remote processor | |
259 | * @rpdev: the rpmsg channel | |
260 | * @data: payload of message | |
261 | * @len: length of payload | |
262 | * | |
263 | * This function sends @data of length @len on the @rpdev channel. | |
264 | * The message will be sent to the remote processor which the @rpdev | |
265 | * channel belongs to, using @rpdev's source and destination addresses. | |
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 | * Returns 0 on success and an appropriate error value on failure. | |
272 | */ | |
273 | static inline | |
274 | int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len) | |
275 | { | |
276 | u32 src = rpdev->src, dst = rpdev->dst; | |
277 | ||
278 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
279 | } | |
280 | ||
281 | /** | |
282 | * rpmsg_sendto() - send a message across to the remote processor, specify dst | |
283 | * @rpdev: the rpmsg channel | |
284 | * @data: payload of message | |
285 | * @len: length of payload | |
286 | * @dst: destination address | |
287 | * | |
288 | * This function sends @data of length @len to the remote @dst address. | |
289 | * The message will be sent to the remote processor which the @rpdev | |
290 | * channel belongs to, using @rpdev's source address. | |
291 | * In case there are no TX buffers available, the function will immediately | |
292 | * return -ENOMEM without waiting until one becomes available. | |
293 | * | |
294 | * Can only be called from process context (for now). | |
295 | * | |
296 | * Returns 0 on success and an appropriate error value on failure. | |
297 | */ | |
298 | static inline | |
299 | int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) | |
300 | { | |
301 | u32 src = rpdev->src; | |
302 | ||
303 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
304 | } | |
305 | ||
306 | /** | |
307 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | |
308 | * @rpdev: the rpmsg channel | |
309 | * @src: source address | |
310 | * @dst: destination address | |
311 | * @data: payload of message | |
312 | * @len: length of payload | |
313 | * | |
314 | * This function sends @data of length @len to the remote @dst address, | |
315 | * and uses @src as the source address. | |
316 | * The message will be sent to the remote processor which the @rpdev | |
317 | * channel belongs to. | |
318 | * In case there are no TX buffers available, the function will immediately | |
319 | * return -ENOMEM without waiting until one becomes available. | |
320 | * | |
321 | * Can only be called from process context (for now). | |
322 | * | |
323 | * Returns 0 on success and an appropriate error value on failure. | |
324 | */ | |
325 | static inline | |
326 | int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, | |
327 | void *data, int len) | |
328 | { | |
329 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
330 | } | |
331 | ||
332 | #endif /* _LINUX_RPMSG_H */ |