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 #define RPMSG_ADDR_ANY 0xFFFFFFFF 45 46 struct rpmsg_device; 47 struct rpmsg_endpoint; 48 struct rpmsg_device_ops; 49 struct rpmsg_endpoint_ops; 50 51 /** 52 * struct rpmsg_channel_info - channel info representation 53 * @name: name of service 54 * @src: local address 55 * @dst: destination address 56 */ 57 struct rpmsg_channel_info { 58 char name[RPMSG_NAME_SIZE]; 59 u32 src; 60 u32 dst; 61 }; 62 63 /** 64 * rpmsg_device - device that belong to the rpmsg bus 65 * @dev: the device struct 66 * @id: device id (used to match between rpmsg drivers and devices) 67 * @driver_override: driver name to force a match 68 * @src: local address 69 * @dst: destination address 70 * @ept: the rpmsg endpoint of this channel 71 * @announce: if set, rpmsg will announce the creation/removal of this channel 72 */ 73 struct rpmsg_device { 74 struct device dev; 75 struct rpmsg_device_id id; 76 char *driver_override; 77 u32 src; 78 u32 dst; 79 struct rpmsg_endpoint *ept; 80 bool announce; 81 82 const struct rpmsg_device_ops *ops; 83 }; 84 85 typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); 86 87 /** 88 * struct rpmsg_endpoint - binds a local rpmsg address to its user 89 * @rpdev: rpmsg channel device 90 * @refcount: when this drops to zero, the ept is deallocated 91 * @cb: rx callback handler 92 * @cb_lock: must be taken before accessing/changing @cb 93 * @addr: local rpmsg address 94 * @priv: private data for the driver's use 95 * 96 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as 97 * it binds an rpmsg address with an rx callback handler. 98 * 99 * Simple rpmsg drivers shouldn't use this struct directly, because 100 * things just work: every rpmsg driver provides an rx callback upon 101 * registering to the bus, and that callback is then bound to its rpmsg 102 * address when the driver is probed. When relevant inbound messages arrive 103 * (i.e. messages which their dst address equals to the src address of 104 * the rpmsg channel), the driver's handler is invoked to process it. 105 * 106 * More complicated drivers though, that do need to allocate additional rpmsg 107 * addresses, and bind them to different rx callbacks, must explicitly 108 * create additional endpoints by themselves (see rpmsg_create_ept()). 109 */ 110 struct rpmsg_endpoint { 111 struct rpmsg_device *rpdev; 112 struct kref refcount; 113 rpmsg_rx_cb_t cb; 114 struct mutex cb_lock; 115 u32 addr; 116 void *priv; 117 118 const struct rpmsg_endpoint_ops *ops; 119 }; 120 121 /** 122 * struct rpmsg_driver - rpmsg driver struct 123 * @drv: underlying device driver 124 * @id_table: rpmsg ids serviced by this driver 125 * @probe: invoked when a matching rpmsg channel (i.e. device) is found 126 * @remove: invoked when the rpmsg channel is removed 127 * @callback: invoked when an inbound message is received on the channel 128 */ 129 struct rpmsg_driver { 130 struct device_driver drv; 131 const struct rpmsg_device_id *id_table; 132 int (*probe)(struct rpmsg_device *dev); 133 void (*remove)(struct rpmsg_device *dev); 134 int (*callback)(struct rpmsg_device *, void *, int, void *, u32); 135 }; 136 137 int register_rpmsg_device(struct rpmsg_device *dev); 138 void unregister_rpmsg_device(struct rpmsg_device *dev); 139 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 140 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 141 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 142 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, 143 rpmsg_rx_cb_t cb, void *priv, 144 struct rpmsg_channel_info chinfo); 145 146 /* use a macro to avoid include chaining to get THIS_MODULE */ 147 #define register_rpmsg_driver(drv) \ 148 __register_rpmsg_driver(drv, THIS_MODULE) 149 150 /** 151 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver 152 * @__rpmsg_driver: rpmsg_driver struct 153 * 154 * Helper macro for rpmsg drivers which do not do anything special in module 155 * init/exit. This eliminates a lot of boilerplate. Each module may only 156 * use this macro once, and calling it replaces module_init() and module_exit() 157 */ 158 #define module_rpmsg_driver(__rpmsg_driver) \ 159 module_driver(__rpmsg_driver, register_rpmsg_driver, \ 160 unregister_rpmsg_driver) 161 162 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); 163 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 164 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 165 void *data, int len); 166 167 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); 168 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); 169 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 170 void *data, int len); 171 172 #endif /* _LINUX_RPMSG_H */ 173