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/* 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 NULL;
}
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 */