2 * Remote processor messaging
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
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9 * modification, are permitted provided that the following conditions
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35 #ifndef _LINUX_RPMSG_H
36 #define _LINUX_RPMSG_H
38 #include <linux/types.h>
39 #include <linux/device.h>
40 #include <linux/mod_devicetable.h>
41 #include <linux/kref.h>
42 #include <linux/mutex.h>
44 /* The feature bitmap for virtio rpmsg */
45 #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
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
56 * Every message sent(/received) on the rpmsg bus begins with this header.
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
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).
80 char name
[RPMSG_NAME_SIZE
];
86 * enum rpmsg_ns_flags - dynamic name service announcement flags
88 * @RPMSG_NS_CREATE: a new remote service was just created
89 * @RPMSG_NS_DESTROY: a known remote service was just destroyed
96 #define RPMSG_ADDR_ANY 0xFFFFFFFF
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
110 struct rpmsg_channel
{
111 struct virtproc_info
*vrp
;
113 struct rpmsg_device_id id
;
116 struct rpmsg_endpoint
*ept
;
120 typedef void (*rpmsg_rx_cb_t
)(struct rpmsg_channel
*, void *, int, void *, u32
);
123 * struct rpmsg_endpoint - binds a local rpmsg address to its user
124 * @rpdev: rpmsg channel device
125 * @refcount: when this drops to zero, the ept is deallocated
126 * @cb: rx callback handler
127 * @cb_lock: must be taken before accessing/changing @cb
128 * @addr: local rpmsg address
129 * @priv: private data for the driver's use
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.
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.
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()).
145 struct rpmsg_endpoint
{
146 struct rpmsg_channel
*rpdev
;
147 struct kref refcount
;
149 struct mutex cb_lock
;
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
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
);
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
);
178 rpmsg_send_offchannel_raw(struct rpmsg_channel
*, u32
, u32
, void *, int, bool);
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
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.
193 * Can only be called from process context (for now).
195 * Returns 0 on success and an appropriate error value on failure.
197 static inline int rpmsg_send(struct rpmsg_channel
*rpdev
, void *data
, int len
)
199 u32 src
= rpdev
->src
, dst
= rpdev
->dst
;
201 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, true);
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
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.
218 * Can only be called from process context (for now).
220 * Returns 0 on success and an appropriate error value on failure.
223 int rpmsg_sendto(struct rpmsg_channel
*rpdev
, void *data
, int len
, u32 dst
)
225 u32 src
= rpdev
->src
;
227 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, true);
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
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.
246 * Can only be called from process context (for now).
248 * Returns 0 on success and an appropriate error value on failure.
251 int rpmsg_send_offchannel(struct rpmsg_channel
*rpdev
, u32 src
, u32 dst
,
254 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, true);
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
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.
269 * Can only be called from process context (for now).
271 * Returns 0 on success and an appropriate error value on failure.
274 int rpmsg_trysend(struct rpmsg_channel
*rpdev
, void *data
, int len
)
276 u32 src
= rpdev
->src
, dst
= rpdev
->dst
;
278 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, false);
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
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.
294 * Can only be called from process context (for now).
296 * Returns 0 on success and an appropriate error value on failure.
299 int rpmsg_trysendto(struct rpmsg_channel
*rpdev
, void *data
, int len
, u32 dst
)
301 u32 src
= rpdev
->src
;
303 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, false);
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
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.
321 * Can only be called from process context (for now).
323 * Returns 0 on success and an appropriate error value on failure.
326 int rpmsg_trysend_offchannel(struct rpmsg_channel
*rpdev
, u32 src
, u32 dst
,
329 return rpmsg_send_offchannel_raw(rpdev
, src
, dst
, data
, len
, false);
332 #endif /* _LINUX_RPMSG_H */
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