include/linux/rpmsg.h

   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 */