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