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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>
41
42/* The feature bitmap for virtio rpmsg */
43#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
44
45/**
46 * struct rpmsg_hdr - common header for all rpmsg messages
47 * @src: source address
48 * @dst: destination address
49 * @reserved: reserved for future use
50 * @len: length of payload (in bytes)
51 * @flags: message flags
52 * @data: @len bytes of message payload data
53 *
54 * Every message sent(/received) on the rpmsg bus begins with this header.
55 */
56struct rpmsg_hdr {
57 u32 src;
58 u32 dst;
59 u32 reserved;
60 u16 len;
61 u16 flags;
62 u8 data[0];
63} __packed;
64
65/**
66 * struct rpmsg_ns_msg - dynamic name service announcement message
67 * @name: name of remote service that is published
68 * @addr: address of remote service that is published
69 * @flags: indicates whether service is created or destroyed
70 *
71 * This message is sent across to publish a new service, or announce
72 * about its removal. When we receive these messages, an appropriate
73 * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
74 * or ->remove() handler of the appropriate rpmsg driver will be invoked
75 * (if/as-soon-as one is registered).
76 */
77struct rpmsg_ns_msg {
78 char name[RPMSG_NAME_SIZE];
79 u32 addr;
80 u32 flags;
81} __packed;
82
83/**
84 * enum rpmsg_ns_flags - dynamic name service announcement flags
85 *
86 * @RPMSG_NS_CREATE: a new remote service was just created
87 * @RPMSG_NS_DESTROY: a known remote service was just destroyed
88 */
89enum rpmsg_ns_flags {
90 RPMSG_NS_CREATE = 0,
91 RPMSG_NS_DESTROY = 1,
92};
93
94#define RPMSG_ADDR_ANY 0xFFFFFFFF
95
96struct virtproc_info;
97
98/**
99 * rpmsg_channel - devices that belong to the rpmsg bus are called channels
100 * @vrp: the remote processor this channel belongs to
101 * @dev: the device struct
102 * @id: device id (used to match between rpmsg drivers and devices)
103 * @src: local address
104 * @dst: destination address
105 * @ept: the rpmsg endpoint of this channel
106 * @announce: if set, rpmsg will announce the creation/removal of this channel
107 */
108struct rpmsg_channel {
109 struct virtproc_info *vrp;
110 struct device dev;
111 struct rpmsg_device_id id;
112 u32 src;
113 u32 dst;
114 struct rpmsg_endpoint *ept;
115 bool announce;
116};
117
118typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32);
119
120/**
121 * struct rpmsg_endpoint - binds a local rpmsg address to its user
122 * @rpdev: rpmsg channel device
123 * @cb: rx callback handler
124 * @addr: local rpmsg address
125 * @priv: private data for the driver's use
126 *
127 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
128 * it binds an rpmsg address with an rx callback handler.
129 *
130 * Simple rpmsg drivers shouldn't use this struct directly, because
131 * things just work: every rpmsg driver provides an rx callback upon
132 * registering to the bus, and that callback is then bound to its rpmsg
133 * address when the driver is probed. When relevant inbound messages arrive
134 * (i.e. messages which their dst address equals to the src address of
135 * the rpmsg channel), the driver's handler is invoked to process it.
136 *
137 * More complicated drivers though, that do need to allocate additional rpmsg
138 * addresses, and bind them to different rx callbacks, must explicitly
139 * create additional endpoints by themselves (see rpmsg_create_ept()).
140 */
141struct rpmsg_endpoint {
142 struct rpmsg_channel *rpdev;
143 rpmsg_rx_cb_t cb;
144 u32 addr;
145 void *priv;
146};
147
148/**
149 * struct rpmsg_driver - rpmsg driver struct
150 * @drv: underlying device driver
151 * @id_table: rpmsg ids serviced by this driver
152 * @probe: invoked when a matching rpmsg channel (i.e. device) is found
153 * @remove: invoked when the rpmsg channel is removed
154 * @callback: invoked when an inbound message is received on the channel
155 */
156struct rpmsg_driver {
157 struct device_driver drv;
158 const struct rpmsg_device_id *id_table;
159 int (*probe)(struct rpmsg_channel *dev);
160 void (*remove)(struct rpmsg_channel *dev);
161 void (*callback)(struct rpmsg_channel *, void *, int, void *, u32);
162};
163
164int register_rpmsg_device(struct rpmsg_channel *dev);
165void unregister_rpmsg_device(struct rpmsg_channel *dev);
166int register_rpmsg_driver(struct rpmsg_driver *drv);
167void unregister_rpmsg_driver(struct rpmsg_driver *drv);
168void rpmsg_destroy_ept(struct rpmsg_endpoint *);
169struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *,
170 rpmsg_rx_cb_t cb, void *priv, u32 addr);
171int
172rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool);
173
174/**
175 * rpmsg_send() - send a message across to the remote processor
176 * @rpdev: the rpmsg channel
177 * @data: payload of message
178 * @len: length of payload
179 *
180 * This function sends @data of length @len on the @rpdev channel.
181 * The message will be sent to the remote processor which the @rpdev
182 * channel belongs to, using @rpdev's source and destination addresses.
183 * In case there are no TX buffers available, the function will block until
184 * one becomes available, or a timeout of 15 seconds elapses. When the latter
185 * happens, -ERESTARTSYS is returned.
186 *
187 * Can only be called from process context (for now).
188 *
189 * Returns 0 on success and an appropriate error value on failure.
190 */
191static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len)
192{
193 u32 src = rpdev->src, dst = rpdev->dst;
194
195 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
196}
197
198/**
199 * rpmsg_sendto() - send a message across to the remote processor, specify dst
200 * @rpdev: the rpmsg channel
201 * @data: payload of message
202 * @len: length of payload
203 * @dst: destination address
204 *
205 * This function sends @data of length @len to the remote @dst address.
206 * The message will be sent to the remote processor which the @rpdev
207 * channel belongs to, using @rpdev's source address.
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 * Returns 0 on success and an appropriate error value on failure.
215 */
216static inline
217int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
218{
219 u32 src = rpdev->src;
220
221 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
222}
223
224/**
225 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
226 * @rpdev: the rpmsg channel
227 * @src: source address
228 * @dst: destination address
229 * @data: payload of message
230 * @len: length of payload
231 *
232 * This function sends @data of length @len to the remote @dst address,
233 * and uses @src as the source address.
234 * The message will be sent to the remote processor which the @rpdev
235 * channel belongs to.
236 * In case there are no TX buffers available, the function will block until
237 * one becomes available, or a timeout of 15 seconds elapses. When the latter
238 * happens, -ERESTARTSYS is returned.
239 *
240 * Can only be called from process context (for now).
241 *
242 * Returns 0 on success and an appropriate error value on failure.
243 */
244static inline
245int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
246 void *data, int len)
247{
248 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
249}
250
251/**
252 * rpmsg_send() - send a message across to the remote processor
253 * @rpdev: the rpmsg channel
254 * @data: payload of message
255 * @len: length of payload
256 *
257 * This function sends @data of length @len on the @rpdev channel.
258 * The message will be sent to the remote processor which the @rpdev
259 * channel belongs to, using @rpdev's source and destination addresses.
260 * In case there are no TX buffers available, the function will immediately
261 * return -ENOMEM without waiting until one becomes available.
262 *
263 * Can only be called from process context (for now).
264 *
265 * Returns 0 on success and an appropriate error value on failure.
266 */
267static inline
268int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len)
269{
270 u32 src = rpdev->src, dst = rpdev->dst;
271
272 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
273}
274
275/**
276 * rpmsg_sendto() - send a message across to the remote processor, specify dst
277 * @rpdev: the rpmsg channel
278 * @data: payload of message
279 * @len: length of payload
280 * @dst: destination address
281 *
282 * This function sends @data of length @len to the remote @dst address.
283 * The message will be sent to the remote processor which the @rpdev
284 * channel belongs to, using @rpdev's source address.
285 * In case there are no TX buffers available, the function will immediately
286 * return -ENOMEM without waiting until one becomes available.
287 *
288 * Can only be called from process context (for now).
289 *
290 * Returns 0 on success and an appropriate error value on failure.
291 */
292static inline
293int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
294{
295 u32 src = rpdev->src;
296
297 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
298}
299
300/**
301 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
302 * @rpdev: the rpmsg channel
303 * @src: source address
304 * @dst: destination address
305 * @data: payload of message
306 * @len: length of payload
307 *
308 * This function sends @data of length @len to the remote @dst address,
309 * and uses @src as the source address.
310 * The message will be sent to the remote processor which the @rpdev
311 * channel belongs to.
312 * In case there are no TX buffers available, the function will immediately
313 * return -ENOMEM without waiting until one becomes available.
314 *
315 * Can only be called from process context (for now).
316 *
317 * Returns 0 on success and an appropriate error value on failure.
318 */
319static inline
320int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
321 void *data, int len)
322{
323 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
324}
325
326#endif /* _LINUX_RPMSG_H */