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/err.h> 41 #include <linux/mod_devicetable.h> 42 #include <linux/kref.h> 43 #include <linux/mutex.h> 44 #include <linux/poll.h> 45 46 #define RPMSG_ADDR_ANY 0xFFFFFFFF 47 48 struct rpmsg_device; 49 struct rpmsg_endpoint; 50 struct rpmsg_device_ops; 51 struct rpmsg_endpoint_ops; 52 53 /** 54 * struct rpmsg_channel_info - channel info representation 55 * @name: name of service 56 * @src: local address 57 * @dst: destination address 58 */ 59 struct rpmsg_channel_info { 60 char name[RPMSG_NAME_SIZE]; 61 u32 src; 62 u32 dst; 63 }; 64 65 /** 66 * rpmsg_device - device that belong to the rpmsg bus 67 * @dev: the device struct 68 * @id: device id (used to match between rpmsg drivers and devices) 69 * @driver_override: driver name to force a match 70 * @src: local address 71 * @dst: destination address 72 * @ept: the rpmsg endpoint of this channel 73 * @announce: if set, rpmsg will announce the creation/removal of this channel 74 */ 75 struct rpmsg_device { 76 struct device dev; 77 struct rpmsg_device_id id; 78 char *driver_override; 79 u32 src; 80 u32 dst; 81 struct rpmsg_endpoint *ept; 82 bool announce; 83 84 const struct rpmsg_device_ops *ops; 85 }; 86 87 typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); 88 89 /** 90 * struct rpmsg_endpoint - binds a local rpmsg address to its user 91 * @rpdev: rpmsg channel device 92 * @refcount: when this drops to zero, the ept is deallocated 93 * @cb: rx callback handler 94 * @cb_lock: must be taken before accessing/changing @cb 95 * @addr: local rpmsg address 96 * @priv: private data for the driver's use 97 * 98 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as 99 * it binds an rpmsg address with an rx callback handler. 100 * 101 * Simple rpmsg drivers shouldn't use this struct directly, because 102 * things just work: every rpmsg driver provides an rx callback upon 103 * registering to the bus, and that callback is then bound to its rpmsg 104 * address when the driver is probed. When relevant inbound messages arrive 105 * (i.e. messages which their dst address equals to the src address of 106 * the rpmsg channel), the driver's handler is invoked to process it. 107 * 108 * More complicated drivers though, that do need to allocate additional rpmsg 109 * addresses, and bind them to different rx callbacks, must explicitly 110 * create additional endpoints by themselves (see rpmsg_create_ept()). 111 */ 112 struct rpmsg_endpoint { 113 struct rpmsg_device *rpdev; 114 struct kref refcount; 115 rpmsg_rx_cb_t cb; 116 struct mutex cb_lock; 117 u32 addr; 118 void *priv; 119 120 const struct rpmsg_endpoint_ops *ops; 121 }; 122 123 /** 124 * struct rpmsg_driver - rpmsg driver struct 125 * @drv: underlying device driver 126 * @id_table: rpmsg ids serviced by this driver 127 * @probe: invoked when a matching rpmsg channel (i.e. device) is found 128 * @remove: invoked when the rpmsg channel is removed 129 * @callback: invoked when an inbound message is received on the channel 130 */ 131 struct rpmsg_driver { 132 struct device_driver drv; 133 const struct rpmsg_device_id *id_table; 134 int (*probe)(struct rpmsg_device *dev); 135 void (*remove)(struct rpmsg_device *dev); 136 int (*callback)(struct rpmsg_device *, void *, int, void *, u32); 137 }; 138 139 #if IS_ENABLED(CONFIG_RPMSG) 140 141 int register_rpmsg_device(struct rpmsg_device *dev); 142 void unregister_rpmsg_device(struct rpmsg_device *dev); 143 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 144 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 145 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 146 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 147 rpmsg_rx_cb_t cb, void *priv, 148 struct rpmsg_channel_info chinfo); 149 150 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 151 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 152 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 153 void *data, int len); 154 155 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 156 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 157 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 158 void *data, int len); 159 160 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, 161 poll_table *wait); 162 163 #else 164 165 static inline int register_rpmsg_device(struct rpmsg_device *dev) 166 { 167 return -ENXIO; 168 } 169 170 static inline void unregister_rpmsg_device(struct rpmsg_device *dev) 171 { 172 /* This shouldn't be possible */ 173 WARN_ON(1); 174 } 175 176 static inline int __register_rpmsg_driver(struct rpmsg_driver *drv, 177 struct module *owner) 178 { 179 /* This shouldn't be possible */ 180 WARN_ON(1); 181 182 return -ENXIO; 183 } 184 185 static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv) 186 { 187 /* This shouldn't be possible */ 188 WARN_ON(1); 189 } 190 191 static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) 192 { 193 /* This shouldn't be possible */ 194 WARN_ON(1); 195 } 196 197 static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, 198 rpmsg_rx_cb_t cb, 199 void *priv, 200 struct rpmsg_channel_info chinfo) 201 { 202 /* This shouldn't be possible */ 203 WARN_ON(1); 204 205 return ERR_PTR(-ENXIO); 206 } 207 208 static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) 209 { 210 /* This shouldn't be possible */ 211 WARN_ON(1); 212 213 return -ENXIO; 214 } 215 216 static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, 217 u32 dst) 218 { 219 /* This shouldn't be possible */ 220 WARN_ON(1); 221 222 return -ENXIO; 223 224 } 225 226 static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, 227 u32 dst, void *data, int len) 228 { 229 /* This shouldn't be possible */ 230 WARN_ON(1); 231 232 return -ENXIO; 233 } 234 235 static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) 236 { 237 /* This shouldn't be possible */ 238 WARN_ON(1); 239 240 return -ENXIO; 241 } 242 243 static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, 244 int len, u32 dst) 245 { 246 /* This shouldn't be possible */ 247 WARN_ON(1); 248 249 return -ENXIO; 250 } 251 252 static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, 253 u32 dst, void *data, int len) 254 { 255 /* This shouldn't be possible */ 256 WARN_ON(1); 257 258 return -ENXIO; 259 } 260 261 static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, 262 struct file *filp, poll_table *wait) 263 { 264 /* This shouldn't be possible */ 265 WARN_ON(1); 266 267 return 0; 268 } 269 270 #endif /* IS_ENABLED(CONFIG_RPMSG) */ 271 272 /* use a macro to avoid include chaining to get THIS_MODULE */ 273 #define register_rpmsg_driver(drv) \ 274 __register_rpmsg_driver(drv, THIS_MODULE) 275 276 /** 277 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 278 * @__rpmsg_driver: rpmsg_driver struct 279 * 280 * Helper macro for rpmsg drivers which do not do anything special in module 281 * init/exit. This eliminates a lot of boilerplate. Each module may only 282 * use this macro once, and calling it replaces module_init() and module_exit() 283 */ 284 #define module_rpmsg_driver(__rpmsg_driver) \ 285 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 286 unregister_rpmsg_driver) 287 288 #endif /* _LINUX_RPMSG_H */ 289