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