1 /* SPDX-License-Identifier: BSD-3-Clause */ 2 /* 3 * Remote processor messaging 4 * 5 * Copyright (C) 2011 Texas Instruments, Inc. 6 * Copyright (C) 2011 Google, Inc. 7 * All rights reserved. 8 */ 9 10 #ifndef _LINUX_RPMSG_H 11 #define _LINUX_RPMSG_H 12 13 #include <linux/types.h> 14 #include <linux/device.h> 15 #include <linux/err.h> 16 #include <linux/mod_devicetable.h> 17 #include <linux/kref.h> 18 #include <linux/mutex.h> 19 #include <linux/poll.h> 20 #include <linux/rpmsg/byteorder.h> 21 #include <uapi/linux/rpmsg.h> 22 23 struct rpmsg_device; 24 struct rpmsg_endpoint; 25 struct rpmsg_device_ops; 26 struct rpmsg_endpoint_ops; 27 28 /** 29 * struct rpmsg_channel_info - channel info representation 30 * @name: name of service 31 * @src: local address 32 * @dst: destination address 33 */ 34 struct rpmsg_channel_info { 35 char name[RPMSG_NAME_SIZE]; 36 u32 src; 37 u32 dst; 38 }; 39 40 /** 41 * rpmsg_device - device that belong to the rpmsg bus 42 * @dev: the device struct 43 * @id: device id (used to match between rpmsg drivers and devices) 44 * @driver_override: driver name to force a match; do not set directly, 45 * because core frees it; use driver_set_override() to 46 * set or clear it. 47 * @src: local address 48 * @dst: destination address 49 * @ept: the rpmsg endpoint of this channel 50 * @announce: if set, rpmsg will announce the creation/removal of this channel 51 * @little_endian: True if transport is using little endian byte representation 52 */ 53 struct rpmsg_device { 54 struct device dev; 55 struct rpmsg_device_id id; 56 const char *driver_override; 57 u32 src; 58 u32 dst; 59 struct rpmsg_endpoint *ept; 60 bool announce; 61 bool little_endian; 62 63 const struct rpmsg_device_ops *ops; 64 }; 65 66 typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); 67 68 /** 69 * struct rpmsg_endpoint - binds a local rpmsg address to its user 70 * @rpdev: rpmsg channel device 71 * @refcount: when this drops to zero, the ept is deallocated 72 * @cb: rx callback handler 73 * @cb_lock: must be taken before accessing/changing @cb 74 * @addr: local rpmsg address 75 * @priv: private data for the driver's use 76 * 77 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as 78 * it binds an rpmsg address with an rx callback handler. 79 * 80 * Simple rpmsg drivers shouldn't use this struct directly, because 81 * things just work: every rpmsg driver provides an rx callback upon 82 * registering to the bus, and that callback is then bound to its rpmsg 83 * address when the driver is probed. When relevant inbound messages arrive 84 * (i.e. messages which their dst address equals to the src address of 85 * the rpmsg channel), the driver's handler is invoked to process it. 86 * 87 * More complicated drivers though, that do need to allocate additional rpmsg 88 * addresses, and bind them to different rx callbacks, must explicitly 89 * create additional endpoints by themselves (see rpmsg_create_ept()). 90 */ 91 struct rpmsg_endpoint { 92 struct rpmsg_device *rpdev; 93 struct kref refcount; 94 rpmsg_rx_cb_t cb; 95 struct mutex cb_lock; 96 u32 addr; 97 void *priv; 98 99 const struct rpmsg_endpoint_ops *ops; 100 }; 101 102 /** 103 * struct rpmsg_driver - rpmsg driver struct 104 * @drv: underlying device driver 105 * @id_table: rpmsg ids serviced by this driver 106 * @probe: invoked when a matching rpmsg channel (i.e. device) is found 107 * @remove: invoked when the rpmsg channel is removed 108 * @callback: invoked when an inbound message is received on the channel 109 */ 110 struct rpmsg_driver { 111 struct device_driver drv; 112 const struct rpmsg_device_id *id_table; 113 int (*probe)(struct rpmsg_device *dev); 114 void (*remove)(struct rpmsg_device *dev); 115 int (*callback)(struct rpmsg_device *, void *, int, void *, u32); 116 }; 117 118 static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val) 119 { 120 if (!rpdev) 121 return __rpmsg16_to_cpu(rpmsg_is_little_endian(), val); 122 else 123 return __rpmsg16_to_cpu(rpdev->little_endian, val); 124 } 125 126 static inline __rpmsg16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val) 127 { 128 if (!rpdev) 129 return __cpu_to_rpmsg16(rpmsg_is_little_endian(), val); 130 else 131 return __cpu_to_rpmsg16(rpdev->little_endian, val); 132 } 133 134 static inline u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, __rpmsg32 val) 135 { 136 if (!rpdev) 137 return __rpmsg32_to_cpu(rpmsg_is_little_endian(), val); 138 else 139 return __rpmsg32_to_cpu(rpdev->little_endian, val); 140 } 141 142 static inline __rpmsg32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val) 143 { 144 if (!rpdev) 145 return __cpu_to_rpmsg32(rpmsg_is_little_endian(), val); 146 else 147 return __cpu_to_rpmsg32(rpdev->little_endian, val); 148 } 149 150 static inline u64 rpmsg64_to_cpu(struct rpmsg_device *rpdev, __rpmsg64 val) 151 { 152 if (!rpdev) 153 return __rpmsg64_to_cpu(rpmsg_is_little_endian(), val); 154 else 155 return __rpmsg64_to_cpu(rpdev->little_endian, val); 156 } 157 158 static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val) 159 { 160 if (!rpdev) 161 return __cpu_to_rpmsg64(rpmsg_is_little_endian(), val); 162 else 163 return __cpu_to_rpmsg64(rpdev->little_endian, val); 164 } 165 166 #if IS_ENABLED(CONFIG_RPMSG) 167 168 int rpmsg_register_device(struct rpmsg_device *rpdev); 169 int rpmsg_unregister_device(struct device *parent, 170 struct rpmsg_channel_info *chinfo); 171 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 172 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 173 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 174 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 175 rpmsg_rx_cb_t cb, void *priv, 176 struct rpmsg_channel_info chinfo); 177 178 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 179 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 180 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 181 void *data, int len); 182 183 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 184 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 185 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 186 void *data, int len); 187 188 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, 189 poll_table *wait); 190 191 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept); 192 193 #else 194 195 static inline int rpmsg_register_device(struct rpmsg_device *rpdev) 196 { 197 return -ENXIO; 198 } 199 200 static inline int rpmsg_unregister_device(struct device *parent, 201 struct rpmsg_channel_info *chinfo) 202 { 203 /* This shouldn't be possible */ 204 WARN_ON(1); 205 206 return -ENXIO; 207 } 208 209 static inline int __register_rpmsg_driver(struct rpmsg_driver *drv, 210 struct module *owner) 211 { 212 /* This shouldn't be possible */ 213 WARN_ON(1); 214 215 return -ENXIO; 216 } 217 218 static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv) 219 { 220 /* This shouldn't be possible */ 221 WARN_ON(1); 222 } 223 224 static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) 225 { 226 /* This shouldn't be possible */ 227 WARN_ON(1); 228 } 229 230 static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, 231 rpmsg_rx_cb_t cb, 232 void *priv, 233 struct rpmsg_channel_info chinfo) 234 { 235 /* This shouldn't be possible */ 236 WARN_ON(1); 237 238 return NULL; 239 } 240 241 static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) 242 { 243 /* This shouldn't be possible */ 244 WARN_ON(1); 245 246 return -ENXIO; 247 } 248 249 static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, 250 u32 dst) 251 { 252 /* This shouldn't be possible */ 253 WARN_ON(1); 254 255 return -ENXIO; 256 257 } 258 259 static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, 260 u32 dst, void *data, int len) 261 { 262 /* This shouldn't be possible */ 263 WARN_ON(1); 264 265 return -ENXIO; 266 } 267 268 static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) 269 { 270 /* This shouldn't be possible */ 271 WARN_ON(1); 272 273 return -ENXIO; 274 } 275 276 static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, 277 int len, u32 dst) 278 { 279 /* This shouldn't be possible */ 280 WARN_ON(1); 281 282 return -ENXIO; 283 } 284 285 static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, 286 u32 dst, void *data, int len) 287 { 288 /* This shouldn't be possible */ 289 WARN_ON(1); 290 291 return -ENXIO; 292 } 293 294 static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, 295 struct file *filp, poll_table *wait) 296 { 297 /* This shouldn't be possible */ 298 WARN_ON(1); 299 300 return 0; 301 } 302 303 static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) 304 { 305 /* This shouldn't be possible */ 306 WARN_ON(1); 307 308 return -ENXIO; 309 } 310 311 #endif /* IS_ENABLED(CONFIG_RPMSG) */ 312 313 /* use a macro to avoid include chaining to get THIS_MODULE */ 314 #define register_rpmsg_driver(drv) \ 315 __register_rpmsg_driver(drv, THIS_MODULE) 316 317 /** 318 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 319 * @__rpmsg_driver: rpmsg_driver struct 320 * 321 * Helper macro for rpmsg drivers which do not do anything special in module 322 * init/exit. This eliminates a lot of boilerplate. Each module may only 323 * use this macro once, and calling it replaces module_init() and module_exit() 324 */ 325 #define module_rpmsg_driver(__rpmsg_driver) \ 326 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 327 unregister_rpmsg_driver) 328 329 #endif /* _LINUX_RPMSG_H */ 330