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 23struct rpmsg_device; 24struct rpmsg_endpoint; 25struct rpmsg_device_ops; 26struct 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 */ 34struct 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 */ 53struct 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 66typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); 67typedef 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 */ 93struct 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 */ 114struct 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 123static 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 131static 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 139static 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 147static 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 155static 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 163static 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 173int rpmsg_register_device_override(struct rpmsg_device *rpdev, 174 const char *driver_override); 175int rpmsg_register_device(struct rpmsg_device *rpdev); 176int rpmsg_unregister_device(struct device *parent, 177 struct rpmsg_channel_info *chinfo); 178int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 179void unregister_rpmsg_driver(struct rpmsg_driver *drv); 180void rpmsg_destroy_ept(struct rpmsg_endpoint *); 181struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 182 rpmsg_rx_cb_t cb, void *priv, 183 struct rpmsg_channel_info chinfo); 184 185int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 186int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 187int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 188 void *data, int len); 189 190int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 191int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 192int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 193 void *data, int len); 194 195__poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, 196 poll_table *wait); 197 198ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept); 199 200int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst); 201 202#else 203 204static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev, 205 const char *driver_override) 206{ 207 return -ENXIO; 208} 209 210static inline int rpmsg_register_device(struct rpmsg_device *rpdev) 211{ 212 return -ENXIO; 213} 214 215static inline int rpmsg_unregister_device(struct device *parent, 216 struct rpmsg_channel_info *chinfo) 217{ 218 /* This shouldn't be possible */ 219 WARN_ON(1); 220 221 return -ENXIO; 222} 223 224static inline int __register_rpmsg_driver(struct rpmsg_driver *drv, 225 struct module *owner) 226{ 227 /* This shouldn't be possible */ 228 WARN_ON(1); 229 230 return -ENXIO; 231} 232 233static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv) 234{ 235 /* This shouldn't be possible */ 236 WARN_ON(1); 237} 238 239static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) 240{ 241 /* This shouldn't be possible */ 242 WARN_ON(1); 243} 244 245static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, 246 rpmsg_rx_cb_t cb, 247 void *priv, 248 struct rpmsg_channel_info chinfo) 249{ 250 /* This shouldn't be possible */ 251 WARN_ON(1); 252 253 return NULL; 254} 255 256static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) 257{ 258 /* This shouldn't be possible */ 259 WARN_ON(1); 260 261 return -ENXIO; 262} 263 264static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, 265 u32 dst) 266{ 267 /* This shouldn't be possible */ 268 WARN_ON(1); 269 270 return -ENXIO; 271 272} 273 274static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, 275 u32 dst, void *data, int len) 276{ 277 /* This shouldn't be possible */ 278 WARN_ON(1); 279 280 return -ENXIO; 281} 282 283static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) 284{ 285 /* This shouldn't be possible */ 286 WARN_ON(1); 287 288 return -ENXIO; 289} 290 291static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, 292 int len, u32 dst) 293{ 294 /* This shouldn't be possible */ 295 WARN_ON(1); 296 297 return -ENXIO; 298} 299 300static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, 301 u32 dst, void *data, int len) 302{ 303 /* This shouldn't be possible */ 304 WARN_ON(1); 305 306 return -ENXIO; 307} 308 309static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, 310 struct file *filp, poll_table *wait) 311{ 312 /* This shouldn't be possible */ 313 WARN_ON(1); 314 315 return 0; 316} 317 318static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) 319{ 320 /* This shouldn't be possible */ 321 WARN_ON(1); 322 323 return -ENXIO; 324} 325 326static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst) 327{ 328 /* This shouldn't be possible */ 329 WARN_ON(1); 330 331 return -ENXIO; 332} 333 334#endif /* IS_ENABLED(CONFIG_RPMSG) */ 335 336/* use a macro to avoid include chaining to get THIS_MODULE */ 337#define register_rpmsg_driver(drv) \ 338 __register_rpmsg_driver(drv, THIS_MODULE) 339 340/** 341 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 342 * @__rpmsg_driver: rpmsg_driver struct 343 * 344 * Helper macro for rpmsg drivers which do not do anything special in module 345 * init/exit. This eliminates a lot of boilerplate. Each module may only 346 * use this macro once, and calling it replaces module_init() and module_exit() 347 */ 348#define module_rpmsg_driver(__rpmsg_driver) \ 349 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 350 unregister_rpmsg_driver) 351 352#endif /* _LINUX_RPMSG_H */ 353