/* SPDX-License-Identifier: BSD-3-Clause */ /* * Remote processor messaging * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * All rights reserved. */ #ifndef _LINUX_RPMSG_H #define _LINUX_RPMSG_H #include <linux/types.h> #include <linux/device.h> #include <linux/err.h> #include <linux/mod_devicetable.h> #include <linux/kref.h> #include <linux/mutex.h> #include <linux/poll.h> #define RPMSG_ADDR_ANY 0xFFFFFFFF struct rpmsg_device; struct rpmsg_endpoint; struct rpmsg_device_ops; struct rpmsg_endpoint_ops; /** * struct rpmsg_channel_info - channel info representation * @name: name of service * @src: local address * @dst: destination address */ struct rpmsg_channel_info { char name[RPMSG_NAME_SIZE]; u32 src; u32 dst; }; /** * rpmsg_device - device that belong to the rpmsg bus * @dev: the device struct * @id: device id (used to match between rpmsg drivers and devices) * @driver_override: driver name to force a match * @src: local address * @dst: destination address * @ept: the rpmsg endpoint of this channel * @announce: if set, rpmsg will announce the creation/removal of this channel */ struct rpmsg_device { struct device dev; struct rpmsg_device_id id; char *driver_override; u32 src; u32 dst; struct rpmsg_endpoint *ept; bool announce; const struct rpmsg_device_ops *ops; }; typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); /** * struct rpmsg_endpoint - binds a local rpmsg address to its user * @rpdev: rpmsg channel device * @refcount: when this drops to zero, the ept is deallocated * @cb: rx callback handler * @cb_lock: must be taken before accessing/changing @cb * @addr: local rpmsg address * @priv: private data for the driver's use * * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as * it binds an rpmsg address with an rx callback handler. * * Simple rpmsg drivers shouldn't use this struct directly, because * things just work: every rpmsg driver provides an rx callback upon * registering to the bus, and that callback is then bound to its rpmsg * address when the driver is probed. When relevant inbound messages arrive * (i.e. messages which their dst address equals to the src address of * the rpmsg channel), the driver's handler is invoked to process it. * * More complicated drivers though, that do need to allocate additional rpmsg * addresses, and bind them to different rx callbacks, must explicitly * create additional endpoints by themselves (see rpmsg_create_ept()). */ struct rpmsg_endpoint { struct rpmsg_device *rpdev; struct kref refcount; rpmsg_rx_cb_t cb; struct mutex cb_lock; u32 addr; void *priv; const struct rpmsg_endpoint_ops *ops; }; /** * struct rpmsg_driver - rpmsg driver struct * @drv: underlying device driver * @id_table: rpmsg ids serviced by this driver * @probe: invoked when a matching rpmsg channel (i.e. device) is found * @remove: invoked when the rpmsg channel is removed * @callback: invoked when an inbound message is received on the channel */ struct rpmsg_driver { struct device_driver drv; const struct rpmsg_device_id *id_table; int (*probe)(struct rpmsg_device *dev); void (*remove)(struct rpmsg_device *dev); int (*callback)(struct rpmsg_device *, void *, int, void *, u32); }; #if IS_ENABLED(CONFIG_RPMSG) int register_rpmsg_device(struct rpmsg_device *dev); void unregister_rpmsg_device(struct rpmsg_device *dev); int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); void unregister_rpmsg_driver(struct rpmsg_driver *drv); void rpmsg_destroy_ept(struct rpmsg_endpoint *); struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *, rpmsg_rx_cb_t cb, void *priv, struct rpmsg_channel_info chinfo); int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, void *data, int len); int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst); int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, void *data, int len); __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, poll_table *wait); #else static inline int register_rpmsg_device(struct rpmsg_device *dev) { return -ENXIO; } static inline void unregister_rpmsg_device(struct rpmsg_device *dev) { /* This shouldn't be possible */ WARN_ON(1); } static inline int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv) { /* This shouldn't be possible */ WARN_ON(1); } static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) { /* This shouldn't be possible */ WARN_ON(1); } static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv, struct rpmsg_channel_info chinfo) { /* This shouldn't be possible */ WARN_ON(1); return ERR_PTR(-ENXIO); } static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, void *data, int len) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, void *data, int len) { /* This shouldn't be possible */ WARN_ON(1); return -ENXIO; } static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, poll_table *wait) { /* This shouldn't be possible */ WARN_ON(1); return 0; } #endif /* IS_ENABLED(CONFIG_RPMSG) */ /* use a macro to avoid include chaining to get THIS_MODULE */ #define register_rpmsg_driver(drv) \ __register_rpmsg_driver(drv, THIS_MODULE) /** * module_rpmsg_driver() - Helper macro for registering an rpmsg driver * @__rpmsg_driver: rpmsg_driver struct * * Helper macro for rpmsg drivers which do not do anything special in module * init/exit. This eliminates a lot of boilerplate. Each module may only * use this macro once, and calling it replaces module_init() and module_exit() */ #define module_rpmsg_driver(__rpmsg_driver) \ module_driver(__rpmsg_driver, register_rpmsg_driver, \ unregister_rpmsg_driver) #endif /* _LINUX_RPMSG_H */