1 /* 2 * Remote processor messaging 3 * 4 * Copyright (C) 2011 Texas Instruments, Inc. 5 * Copyright (C) 2011 Google, Inc. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * * Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * * Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * * Neither the name Texas Instruments nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #ifndef _LINUX_RPMSG_H 36 #define _LINUX_RPMSG_H 37 38 #include <linux/types.h> 39 #include <linux/device.h> 40 #include <linux/mod_devicetable.h> 41 #include <linux/kref.h> 42 #include <linux/mutex.h> 43 44 /* The feature bitmap for virtio rpmsg */ 45 #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ 46 47 /** 48 * struct rpmsg_hdr - common header for all rpmsg messages 49 * @src: source address 50 * @dst: destination address 51 * @reserved: reserved for future use 52 * @len: length of payload (in bytes) 53 * @flags: message flags 54 * @data: @len bytes of message payload data 55 * 56 * Every message sent(/received) on the rpmsg bus begins with this header. 57 */ 58 struct rpmsg_hdr { 59 u32 src; 60 u32 dst; 61 u32 reserved; 62 u16 len; 63 u16 flags; 64 u8 data[0]; 65 } __packed; 66 67 /** 68 * struct rpmsg_ns_msg - dynamic name service announcement message 69 * @name: name of remote service that is published 70 * @addr: address of remote service that is published 71 * @flags: indicates whether service is created or destroyed 72 * 73 * This message is sent across to publish a new service, or announce 74 * about its removal. When we receive these messages, an appropriate 75 * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe() 76 * or ->remove() handler of the appropriate rpmsg driver will be invoked 77 * (if/as-soon-as one is registered). 78 */ 79 struct rpmsg_ns_msg { 80 char name[RPMSG_NAME_SIZE]; 81 u32 addr; 82 u32 flags; 83 } __packed; 84 85 /** 86 * enum rpmsg_ns_flags - dynamic name service announcement flags 87 * 88 * @RPMSG_NS_CREATE: a new remote service was just created 89 * @RPMSG_NS_DESTROY: a known remote service was just destroyed 90 */ 91 enum rpmsg_ns_flags { 92 RPMSG_NS_CREATE = 0, 93 RPMSG_NS_DESTROY = 1, 94 }; 95 96 #define RPMSG_ADDR_ANY 0xFFFFFFFF 97 98 struct virtproc_info; 99 struct rpmsg_device; 100 struct rpmsg_endpoint; 101 struct rpmsg_device_ops; 102 struct rpmsg_endpoint_ops; 103 104 /** 105 * struct rpmsg_channel_info - channel info representation 106 * @name: name of service 107 * @src: local address 108 * @dst: destination address 109 */ 110 struct rpmsg_channel_info { 111 char name[RPMSG_NAME_SIZE]; 112 u32 src; 113 u32 dst; 114 }; 115 116 /** 117 * rpmsg_device - device that belong to the rpmsg bus 118 * @vrp: the remote processor this channel belongs to 119 * @dev: the device struct 120 * @id: device id (used to match between rpmsg drivers and devices) 121 * @src: local address 122 * @dst: destination address 123 * @ept: the rpmsg endpoint of this channel 124 * @announce: if set, rpmsg will announce the creation/removal of this channel 125 */ 126 struct rpmsg_device { 127 struct virtproc_info *vrp; 128 struct device dev; 129 struct rpmsg_device_id id; 130 u32 src; 131 u32 dst; 132 struct rpmsg_endpoint *ept; 133 bool announce; 134 135 const struct rpmsg_device_ops *ops; 136 }; 137 138 typedef void (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); 139 140 /** 141 * struct rpmsg_endpoint - binds a local rpmsg address to its user 142 * @rpdev: rpmsg channel device 143 * @refcount: when this drops to zero, the ept is deallocated 144 * @cb: rx callback handler 145 * @cb_lock: must be taken before accessing/changing @cb 146 * @addr: local rpmsg address 147 * @priv: private data for the driver's use 148 * 149 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as 150 * it binds an rpmsg address with an rx callback handler. 151 * 152 * Simple rpmsg drivers shouldn't use this struct directly, because 153 * things just work: every rpmsg driver provides an rx callback upon 154 * registering to the bus, and that callback is then bound to its rpmsg 155 * address when the driver is probed. When relevant inbound messages arrive 156 * (i.e. messages which their dst address equals to the src address of 157 * the rpmsg channel), the driver's handler is invoked to process it. 158 * 159 * More complicated drivers though, that do need to allocate additional rpmsg 160 * addresses, and bind them to different rx callbacks, must explicitly 161 * create additional endpoints by themselves (see rpmsg_create_ept()). 162 */ 163 struct rpmsg_endpoint { 164 struct rpmsg_device *rpdev; 165 struct kref refcount; 166 rpmsg_rx_cb_t cb; 167 struct mutex cb_lock; 168 u32 addr; 169 void *priv; 170 171 const struct rpmsg_endpoint_ops *ops; 172 }; 173 174 /** 175 * struct rpmsg_driver - rpmsg driver struct 176 * @drv: underlying device driver 177 * @id_table: rpmsg ids serviced by this driver 178 * @probe: invoked when a matching rpmsg channel (i.e. device) is found 179 * @remove: invoked when the rpmsg channel is removed 180 * @callback: invoked when an inbound message is received on the channel 181 */ 182 struct rpmsg_driver { 183 struct device_driver drv; 184 const struct rpmsg_device_id *id_table; 185 int (*probe)(struct rpmsg_device *dev); 186 void (*remove)(struct rpmsg_device *dev); 187 void (*callback)(struct rpmsg_device *, void *, int, void *, u32); 188 }; 189 190 int register_rpmsg_device(struct rpmsg_device *dev); 191 void unregister_rpmsg_device(struct rpmsg_device *dev); 192 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 193 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 194 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 195 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 196 rpmsg_rx_cb_t cb, void *priv, 197 struct rpmsg_channel_info chinfo); 198 199 /* use a macro to avoid include chaining to get THIS_MODULE */ 200 #define register_rpmsg_driver(drv) \ 201 __register_rpmsg_driver(drv, THIS_MODULE) 202 203 /** 204 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 205 * @__rpmsg_driver: rpmsg_driver struct 206 * 207 * Helper macro for rpmsg drivers which do not do anything special in module 208 * init/exit. This eliminates a lot of boilerplate. Each module may only 209 * use this macro once, and calling it replaces module_init() and module_exit() 210 */ 211 #define module_rpmsg_driver(__rpmsg_driver) \ 212 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 213 unregister_rpmsg_driver) 214 215 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 216 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 217 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 218 void *data, int len); 219 220 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 221 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 222 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 223 void *data, int len); 224 225 #endif /* _LINUX_RPMSG_H */ 226