2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-21 11:44:01 +08:00
linux-next/drivers/rpmsg/rpmsg_internal.h
Bjorn Andersson c0cdc19f84 rpmsg: Driver for user space endpoint interface
This driver allows rpmsg instances to expose access to rpmsg endpoints
to user space processes. It provides a control interface, allowing
userspace to export endpoints and an endpoint interface for each exposed
endpoint.

The implementation is based on prior art by Texas Instrument, Google,
PetaLogix and was derived from a FreeRTOS performance statistics driver
written by Michal Simek.

The control interface provides a "create endpoint" ioctl, which is fed a
name, source and destination address. The three values are used to
create the endpoint, in a backend-specific way, and a rpmsg endpoint
device is created - with the three parameters are available in sysfs for
udev usage.

E.g. to create an endpoint device for one of the Qualcomm SMD channel
related to DIAG one would issue:

  struct rpmsg_endpoint_info info = { "DIAG_CNTL", 0, 0 };
  int fd = open("/dev/rpmsg_ctrl0", O_RDWR);
  ioctl(fd, RPMSG_CREATE_EPT_IOCTL, &info);

Each created endpoint device shows up as an individual character device
in /dev, allowing permission to be controlled on a per-endpoint basis.
The rpmsg endpoint will be created and destroyed following the opening
and closing of the endpoint device, allowing rpmsg backends to open and
close the physical channel, if supported by the wire protocol.

Cc: Marek Novak <marek.novak@nxp.com>
Cc: Matteo Sartori <matteo.sartori@t3lab.it>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2017-01-18 10:43:15 -08:00

101 lines
3.7 KiB
C

/*
* remote processor messaging bus internals
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __RPMSG_INTERNAL_H__
#define __RPMSG_INTERNAL_H__
#include <linux/rpmsg.h>
#include <linux/poll.h>
#define to_rpmsg_device(d) container_of(d, struct rpmsg_device, dev)
#define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv)
/**
* struct rpmsg_device_ops - indirection table for the rpmsg_device operations
* @create_ept: create backend-specific endpoint, requried
* @announce_create: announce presence of new channel, optional
* @announce_destroy: announce destruction of channel, optional
*
* Indirection table for the operations that a rpmsg backend should implement.
* @announce_create and @announce_destroy are optional as the backend might
* advertise new channels implicitly by creating the endpoints.
*/
struct rpmsg_device_ops {
struct rpmsg_endpoint *(*create_ept)(struct rpmsg_device *rpdev,
rpmsg_rx_cb_t cb, void *priv,
struct rpmsg_channel_info chinfo);
int (*announce_create)(struct rpmsg_device *ept);
int (*announce_destroy)(struct rpmsg_device *ept);
};
/**
* struct rpmsg_endpoint_ops - indirection table for rpmsg_endpoint operations
* @destroy_ept: destroy the given endpoint, required
* @send: see @rpmsg_send(), required
* @sendto: see @rpmsg_sendto(), optional
* @send_offchannel: see @rpmsg_send_offchannel(), optional
* @trysend: see @rpmsg_trysend(), required
* @trysendto: see @rpmsg_trysendto(), optional
* @trysend_offchannel: see @rpmsg_trysend_offchannel(), optional
*
* Indirection table for the operations that a rpmsg backend should implement.
* In addition to @destroy_ept, the backend must at least implement @send and
* @trysend, while the variants sending data off-channel are optional.
*/
struct rpmsg_endpoint_ops {
void (*destroy_ept)(struct rpmsg_endpoint *ept);
int (*send)(struct rpmsg_endpoint *ept, void *data, int len);
int (*sendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
int (*send_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
void *data, int len);
int (*trysend)(struct rpmsg_endpoint *ept, void *data, int len);
int (*trysendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
int (*trysend_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
void *data, int len);
unsigned int (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
poll_table *wait);
};
int rpmsg_register_device(struct rpmsg_device *rpdev);
int rpmsg_unregister_device(struct device *parent,
struct rpmsg_channel_info *chinfo);
struct device *rpmsg_find_device(struct device *parent,
struct rpmsg_channel_info *chinfo);
/**
* rpmsg_chrdev_register_device() - register chrdev device based on rpdev
* @rpdev: prepared rpdev to be used for creating endpoints
*
* This function wraps rpmsg_register_device() preparing the rpdev for use as
* basis for the rpmsg chrdev.
*/
static inline int rpmsg_chrdev_register_device(struct rpmsg_device *rpdev)
{
strcpy(rpdev->id.name, "rpmsg_chrdev");
rpdev->driver_override = "rpmsg_chrdev";
return rpmsg_register_device(rpdev);
}
#endif