2 * Remote processor messaging
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
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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_driver(struct rpmsg_driver *drv, struct module *owner);
171 void unregister_rpmsg_driver(struct rpmsg_driver *drv);
172 void rpmsg_destroy_ept(struct rpmsg_endpoint *);
173 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *,
174 rpmsg_rx_cb_t cb, void *priv, u32 addr);
176 rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool);
178 /* use a macro to avoid include chaining to get THIS_MODULE */
179 #define register_rpmsg_driver(drv) \
180 __register_rpmsg_driver(drv, THIS_MODULE)
183 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver
184 * @__rpmsg_driver: rpmsg_driver struct
186 * Helper macro for rpmsg drivers which do not do anything special in module
187 * init/exit. This eliminates a lot of boilerplate. Each module may only
188 * use this macro once, and calling it replaces module_init() and module_exit()
190 #define module_rpmsg_driver(__rpmsg_driver) \
191 module_driver(__rpmsg_driver, register_rpmsg_driver, \
192 unregister_rpmsg_driver)
195 * rpmsg_send() - send a message across to the remote processor
196 * @ept: the rpmsg endpoint
197 * @data: payload of message
198 * @len: length of payload
200 * This function sends @data of length @len on the @ept endpoint.
201 * The message will be sent to the remote processor which the @ept
202 * endpoint belongs to, using @ept's address and its associated rpmsg
203 * device destination addresses.
204 * In case there are no TX buffers available, the function will block until
205 * one becomes available, or a timeout of 15 seconds elapses. When the latter
206 * happens, -ERESTARTSYS is returned.
208 * Can only be called from process context (for now).
210 * Returns 0 on success and an appropriate error value on failure.
212 static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
214 struct rpmsg_channel *rpdev = ept->rpdev;
215 u32 src = ept->addr, dst = rpdev->dst;
217 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
221 * rpmsg_sendto() - send a message across to the remote processor, specify dst
222 * @ept: the rpmsg endpoint
223 * @data: payload of message
224 * @len: length of payload
225 * @dst: destination address
227 * This function sends @data of length @len to the remote @dst address.
228 * The message will be sent to the remote processor which the @ept
229 * endpoint belongs to, using @ept's address as source.
230 * In case there are no TX buffers available, the function will block until
231 * one becomes available, or a timeout of 15 seconds elapses. When the latter
232 * happens, -ERESTARTSYS is returned.
234 * Can only be called from process context (for now).
236 * Returns 0 on success and an appropriate error value on failure.
239 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
241 struct rpmsg_channel *rpdev = ept->rpdev;
244 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
248 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
249 * @ept: the rpmsg endpoint
250 * @src: source address
251 * @dst: destination address
252 * @data: payload of message
253 * @len: length of payload
255 * This function sends @data of length @len to the remote @dst address,
256 * and uses @src as the source address.
257 * The message will be sent to the remote processor which the @ept
258 * endpoint belongs to.
259 * In case there are no TX buffers available, the function will block until
260 * one becomes available, or a timeout of 15 seconds elapses. When the latter
261 * happens, -ERESTARTSYS is returned.
263 * Can only be called from process context (for now).
265 * Returns 0 on success and an appropriate error value on failure.
268 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
271 struct rpmsg_channel *rpdev = ept->rpdev;
273 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
277 * rpmsg_send() - send a message across to the remote processor
278 * @ept: the rpmsg endpoint
279 * @data: payload of message
280 * @len: length of payload
282 * This function sends @data of length @len on the @ept endpoint.
283 * The message will be sent to the remote processor which the @ept
284 * endpoint belongs to, using @ept's address as source and its associated
285 * rpdev's address as destination.
286 * In case there are no TX buffers available, the function will immediately
287 * return -ENOMEM without waiting until one becomes available.
289 * Can only be called from process context (for now).
291 * Returns 0 on success and an appropriate error value on failure.
294 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
296 struct rpmsg_channel *rpdev = ept->rpdev;
297 u32 src = ept->addr, dst = rpdev->dst;
299 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
303 * rpmsg_sendto() - send a message across to the remote processor, specify dst
304 * @ept: the rpmsg endpoint
305 * @data: payload of message
306 * @len: length of payload
307 * @dst: destination address
309 * This function sends @data of length @len to the remote @dst address.
310 * The message will be sent to the remote processor which the @ept
311 * endpoint belongs to, using @ept's address as source.
312 * In case there are no TX buffers available, the function will immediately
313 * return -ENOMEM without waiting until one becomes available.
315 * Can only be called from process context (for now).
317 * Returns 0 on success and an appropriate error value on failure.
320 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
322 struct rpmsg_channel *rpdev = ept->rpdev;
325 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
329 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
330 * @ept: the rpmsg endpoint
331 * @src: source address
332 * @dst: destination address
333 * @data: payload of message
334 * @len: length of payload
336 * This function sends @data of length @len to the remote @dst address,
337 * and uses @src as the source address.
338 * The message will be sent to the remote processor which the @ept
339 * endpoint belongs to.
340 * In case there are no TX buffers available, the function will immediately
341 * return -ENOMEM without waiting until one becomes available.
343 * Can only be called from process context (for now).
345 * Returns 0 on success and an appropriate error value on failure.
348 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
351 struct rpmsg_channel *rpdev = ept->rpdev;
353 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
356 #endif /* _LINUX_RPMSG_H */