summaryrefslogtreecommitdiffstats
path: root/include/linux/rpmsg.h
blob: 10d6ae8bbb7dfbb56f55f79434e0c900972878db (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*
 * Remote processor messaging
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Copyright (C) 2011 Google, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 * * Neither the name Texas Instruments nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _LINUX_RPMSG_H
#define _LINUX_RPMSG_H

#include <linux/types.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/mod_devicetable.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/poll.h>

#define RPMSG_ADDR_ANY		0xFFFFFFFF

struct rpmsg_device;
struct rpmsg_endpoint;
struct rpmsg_device_ops;
struct rpmsg_endpoint_ops;

/**
 * struct rpmsg_channel_info - channel info representation
 * @name: name of service
 * @src: local address
 * @dst: destination address
 */
struct rpmsg_channel_info {
	char name[RPMSG_NAME_SIZE];
	u32 src;
	u32 dst;
};

/**
 * rpmsg_device - device that belong to the rpmsg bus
 * @dev: the device struct
 * @id: device id (used to match between rpmsg drivers and devices)
 * @driver_override: driver name to force a match
 * @src: local address
 * @dst: destination address
 * @ept: the rpmsg endpoint of this channel
 * @announce: if set, rpmsg will announce the creation/removal of this channel
 */
struct rpmsg_device {
	struct device dev;
	struct rpmsg_device_id id;
	char *driver_override;
	u32 src;
	u32 dst;
	struct rpmsg_endpoint *ept;
	bool announce;

	const struct rpmsg_device_ops *ops;
};

typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);

/**
 * struct rpmsg_endpoint - binds a local rpmsg address to its user
 * @rpdev: rpmsg channel device
 * @refcount: when this drops to zero, the ept is deallocated
 * @cb: rx callback handler
 * @cb_lock: must be taken before accessing/changing @cb
 * @addr: local rpmsg address
 * @priv: private data for the driver's use
 *
 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
 * it binds an rpmsg address with an rx callback handler.
 *
 * Simple rpmsg drivers shouldn't use this struct directly, because
 * things just work: every rpmsg driver provides an rx callback upon
 * registering to the bus, and that callback is then bound to its rpmsg
 * address when the driver is probed. When relevant inbound messages arrive
 * (i.e. messages which their dst address equals to the src address of
 * the rpmsg channel), the driver's handler is invoked to process it.
 *
 * More complicated drivers though, that do need to allocate additional rpmsg
 * addresses, and bind them to different rx callbacks, must explicitly
 * create additional endpoints by themselves (see rpmsg_create_ept()).
 */
struct rpmsg_endpoint {
	struct rpmsg_device *rpdev;
	struct kref refcount;
	rpmsg_rx_cb_t cb;
	struct mutex cb_lock;
	u32 addr;
	void *priv;

	const struct rpmsg_endpoint_ops *ops;
};

/**
 * struct rpmsg_driver - rpmsg driver struct
 * @drv: underlying device driver
 * @id_table: rpmsg ids serviced by this driver
 * @probe: invoked when a matching rpmsg channel (i.e. device) is found
 * @remove: invoked when the rpmsg channel is removed
 * @callback: invoked when an inbound message is received on the channel
 */
struct rpmsg_driver {
	struct device_driver drv;
	const struct rpmsg_device_id *id_table;
	int (*probe)(struct rpmsg_device *dev);
	void (*remove)(struct rpmsg_device *dev);
	int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
};

#if IS_ENABLED(CONFIG_RPMSG)

int register_rpmsg_device(struct rpmsg_device *dev);
void unregister_rpmsg_device(struct rpmsg_device *dev);
int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner);
void unregister_rpmsg_driver(struct rpmsg_driver *drv);
void rpmsg_destroy_ept(struct rpmsg_endpoint *);
struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *,
					rpmsg_rx_cb_t cb, void *priv,
					struct rpmsg_channel_info chinfo);

int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
			  void *data, int len);

int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
			     void *data, int len);

unsigned int rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
			poll_table *wait);

#else

static inline int register_rpmsg_device(struct rpmsg_device *dev)
{
	return -ENXIO;
}

static inline void unregister_rpmsg_device(struct rpmsg_device *dev)
{
	/* This shouldn't be possible */
	WARN_ON(1);
}

static inline int __register_rpmsg_driver(struct rpmsg_driver *drv,
					  struct module *owner)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv)
{
	/* This shouldn't be possible */
	WARN_ON(1);
}

static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
{
	/* This shouldn't be possible */
	WARN_ON(1);
}

static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
						      rpmsg_rx_cb_t cb,
						      void *priv,
						      struct rpmsg_channel_info chinfo)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return ERR_PTR(-ENXIO);
}

static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
			       u32 dst)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;

}

static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
					u32 dst, void *data, int len)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
				  int len, u32 dst)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
					   u32 dst, void *data, int len)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return -ENXIO;
}

static inline unsigned int rpmsg_poll(struct rpmsg_endpoint *ept,
				      struct file *filp, poll_table *wait)
{
	/* This shouldn't be possible */
	WARN_ON(1);

	return 0;
}

#endif /* IS_ENABLED(CONFIG_RPMSG) */

/* use a macro to avoid include chaining to get THIS_MODULE */
#define register_rpmsg_driver(drv) \
	__register_rpmsg_driver(drv, THIS_MODULE)

/**
 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver
 * @__rpmsg_driver: rpmsg_driver struct
 *
 * Helper macro for rpmsg drivers which do not do anything special in module
 * init/exit. This eliminates a lot of boilerplate.  Each module may only
 * use this macro once, and calling it replaces module_init() and module_exit()
 */
#define module_rpmsg_driver(__rpmsg_driver) \
	module_driver(__rpmsg_driver, register_rpmsg_driver, \
			unregister_rpmsg_driver)

#endif /* _LINUX_RPMSG_H */