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 typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool); 68 69 /** 70 * struct rpmsg_endpoint - binds a local rpmsg address to its user 71 * @rpdev: rpmsg channel device 72 * @refcount: when this drops to zero, the ept is deallocated 73 * @cb: rx callback handler 74 * @flow_cb: remote flow control callback handler 75 * @cb_lock: must be taken before accessing/changing @cb 76 * @addr: local rpmsg address 77 * @priv: private data for the driver's use 78 * 79 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as 80 * it binds an rpmsg address with an rx callback handler. 81 * 82 * Simple rpmsg drivers shouldn't use this struct directly, because 83 * things just work: every rpmsg driver provides an rx callback upon 84 * registering to the bus, and that callback is then bound to its rpmsg 85 * address when the driver is probed. When relevant inbound messages arrive 86 * (i.e. messages which their dst address equals to the src address of 87 * the rpmsg channel), the driver's handler is invoked to process it. 88 * 89 * More complicated drivers though, that do need to allocate additional rpmsg 90 * addresses, and bind them to different rx callbacks, must explicitly 91 * create additional endpoints by themselves (see rpmsg_create_ept()). 92 */ 93 struct rpmsg_endpoint { 94 struct rpmsg_device *rpdev; 95 struct kref refcount; 96 rpmsg_rx_cb_t cb; 97 rpmsg_flowcontrol_cb_t flow_cb; 98 struct mutex cb_lock; 99 u32 addr; 100 void *priv; 101 102 const struct rpmsg_endpoint_ops *ops; 103 }; 104 105 /** 106 * struct rpmsg_driver - rpmsg driver struct 107 * @drv: underlying device driver 108 * @id_table: rpmsg ids serviced by this driver 109 * @probe: invoked when a matching rpmsg channel (i.e. device) is found 110 * @remove: invoked when the rpmsg channel is removed 111 * @callback: invoked when an inbound message is received on the channel 112 * @flowcontrol: invoked when remote side flow control request is received 113 */ 114 struct rpmsg_driver { 115 struct device_driver drv; 116 const struct rpmsg_device_id *id_table; 117 int (*probe)(struct rpmsg_device *dev); 118 void (*remove)(struct rpmsg_device *dev); 119 int (*callback)(struct rpmsg_device *, void *, int, void *, u32); 120 int (*flowcontrol)(struct rpmsg_device *, void *, bool); 121 }; 122 123 static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val) 124 { 125 if (!rpdev) 126 return __rpmsg16_to_cpu(rpmsg_is_little_endian(), val); 127 else 128 return __rpmsg16_to_cpu(rpdev->little_endian, val); 129 } 130 131 static inline __rpmsg16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val) 132 { 133 if (!rpdev) 134 return __cpu_to_rpmsg16(rpmsg_is_little_endian(), val); 135 else 136 return __cpu_to_rpmsg16(rpdev->little_endian, val); 137 } 138 139 static inline u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, __rpmsg32 val) 140 { 141 if (!rpdev) 142 return __rpmsg32_to_cpu(rpmsg_is_little_endian(), val); 143 else 144 return __rpmsg32_to_cpu(rpdev->little_endian, val); 145 } 146 147 static inline __rpmsg32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val) 148 { 149 if (!rpdev) 150 return __cpu_to_rpmsg32(rpmsg_is_little_endian(), val); 151 else 152 return __cpu_to_rpmsg32(rpdev->little_endian, val); 153 } 154 155 static inline u64 rpmsg64_to_cpu(struct rpmsg_device *rpdev, __rpmsg64 val) 156 { 157 if (!rpdev) 158 return __rpmsg64_to_cpu(rpmsg_is_little_endian(), val); 159 else 160 return __rpmsg64_to_cpu(rpdev->little_endian, val); 161 } 162 163 static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val) 164 { 165 if (!rpdev) 166 return __cpu_to_rpmsg64(rpmsg_is_little_endian(), val); 167 else 168 return __cpu_to_rpmsg64(rpdev->little_endian, val); 169 } 170 171 #if IS_ENABLED(CONFIG_RPMSG) 172 173 int rpmsg_register_device_override(struct rpmsg_device *rpdev, 174 const char *driver_override); 175 int rpmsg_register_device(struct rpmsg_device *rpdev); 176 int rpmsg_unregister_device(struct device *parent, 177 struct rpmsg_channel_info *chinfo); 178 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 179 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 180 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 181 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 182 rpmsg_rx_cb_t cb, void *priv, 183 struct rpmsg_channel_info chinfo); 184 185 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 186 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 187 188 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 189 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 190 191 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, 192 poll_table *wait); 193 194 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept); 195 196 int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst); 197 198 #else 199 200 static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev, 201 const char *driver_override) 202 { 203 return -ENXIO; 204 } 205 206 static inline int rpmsg_register_device(struct rpmsg_device *rpdev) 207 { 208 return -ENXIO; 209 } 210 211 static inline int rpmsg_unregister_device(struct device *parent, 212 struct rpmsg_channel_info *chinfo) 213 { 214 /* This shouldn't be possible */ 215 WARN_ON(1); 216 217 return -ENXIO; 218 } 219 220 static inline int __register_rpmsg_driver(struct rpmsg_driver *drv, 221 struct module *owner) 222 { 223 /* This shouldn't be possible */ 224 WARN_ON(1); 225 226 return -ENXIO; 227 } 228 229 static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv) 230 { 231 /* This shouldn't be possible */ 232 WARN_ON(1); 233 } 234 235 static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) 236 { 237 /* This shouldn't be possible */ 238 WARN_ON(1); 239 } 240 241 static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, 242 rpmsg_rx_cb_t cb, 243 void *priv, 244 struct rpmsg_channel_info chinfo) 245 { 246 /* This shouldn't be possible */ 247 WARN_ON(1); 248 249 return NULL; 250 } 251 252 static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) 253 { 254 /* This shouldn't be possible */ 255 WARN_ON(1); 256 257 return -ENXIO; 258 } 259 260 static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, 261 u32 dst) 262 { 263 /* This shouldn't be possible */ 264 WARN_ON(1); 265 266 return -ENXIO; 267 268 } 269 270 static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) 271 { 272 /* This shouldn't be possible */ 273 WARN_ON(1); 274 275 return -ENXIO; 276 } 277 278 static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, 279 int len, u32 dst) 280 { 281 /* This shouldn't be possible */ 282 WARN_ON(1); 283 284 return -ENXIO; 285 } 286 287 static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, 288 struct file *filp, poll_table *wait) 289 { 290 /* This shouldn't be possible */ 291 WARN_ON(1); 292 293 return 0; 294 } 295 296 static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) 297 { 298 /* This shouldn't be possible */ 299 WARN_ON(1); 300 301 return -ENXIO; 302 } 303 304 static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst) 305 { 306 /* This shouldn't be possible */ 307 WARN_ON(1); 308 309 return -ENXIO; 310 } 311 312 #endif /* IS_ENABLED(CONFIG_RPMSG) */ 313 314 /* use a macro to avoid include chaining to get THIS_MODULE */ 315 #define register_rpmsg_driver(drv) \ 316 __register_rpmsg_driver(drv, THIS_MODULE) 317 318 /** 319 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 320 * @__rpmsg_driver: rpmsg_driver struct 321 * 322 * Helper macro for rpmsg drivers which do not do anything special in module 323 * init/exit. This eliminates a lot of boilerplate. Each module may only 324 * use this macro once, and calling it replaces module_init() and module_exit() 325 */ 326 #define module_rpmsg_driver(__rpmsg_driver) \ 327 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 328 unregister_rpmsg_driver) 329 330 #endif /* _LINUX_RPMSG_H */ 331