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