LXR linux/drivers/rpmsg/rpmsg

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) STMicroelectronics 2020 - All Rights Reserved
   4 */
   5#include <linux/device.h>
   6#include <linux/kernel.h>
   7#include <linux/module.h>
   8#include <linux/rpmsg.h>
   9#include <linux/rpmsg/ns.h>
  10#include <linux/slab.h>
  11
  12#include "rpmsg_internal.h"
  13
  14/**
  15 * rpmsg_ns_register_device() - register name service device based on rpdev
  16 * @rpdev: prepared rpdev to be used for creating endpoints
  17 *
  18 * This function wraps rpmsg_register_device() preparing the rpdev for use as
  19 * basis for the rpmsg name service device.
  20 */
  21int rpmsg_ns_register_device(struct rpmsg_device *rpdev)
  22{
  23        strcpy(rpdev->id.name, "rpmsg_ns");
  24        rpdev->driver_override = "rpmsg_ns";
  25        rpdev->src = RPMSG_NS_ADDR;
  26        rpdev->dst = RPMSG_NS_ADDR;
  27
  28        return rpmsg_register_device(rpdev);
  29}
  30EXPORT_SYMBOL(rpmsg_ns_register_device);
  31
  32/* invoked when a name service announcement arrives */
  33static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
  34                       void *priv, u32 src)
  35{
  36        struct rpmsg_ns_msg *msg = data;
  37        struct rpmsg_device *newch;
  38        struct rpmsg_channel_info chinfo;
  39        struct device *dev = rpdev->dev.parent;
  40        int ret;
  41
  42#if defined(CONFIG_DYNAMIC_DEBUG)
  43        dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
  44                         data, len, true);
  45#endif
  46
  47        if (len != sizeof(*msg)) {
  48                dev_err(dev, "malformed ns msg (%d)\n", len);
  49                return -EINVAL;
  50        }
  51
  52        /* don't trust the remote processor for null terminating the name */
  53        msg->name[RPMSG_NAME_SIZE - 1] = '\0';
  54
  55        strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
  56        chinfo.src = RPMSG_ADDR_ANY;
  57        chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr);
  58
  59        dev_info(dev, "%sing channel %s addr 0x%x\n",
  60                 rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY ?
  61                 "destroy" : "creat", msg->name, chinfo.dst);
  62
  63        if (rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY) {
  64                ret = rpmsg_release_channel(rpdev, &chinfo);
  65                if (ret)
  66                        dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
  67        } else {
  68                newch = rpmsg_create_channel(rpdev, &chinfo);
  69                if (!newch)
  70                        dev_err(dev, "rpmsg_create_channel failed\n");
  71        }
  72
  73        return 0;
  74}
  75
  76static int rpmsg_ns_probe(struct rpmsg_device *rpdev)
  77{
  78        struct rpmsg_endpoint *ns_ept;
  79        struct rpmsg_channel_info ns_chinfo = {
  80                .src = RPMSG_NS_ADDR,
  81                .dst = RPMSG_NS_ADDR,
  82                .name = "name_service",
  83        };
  84
  85        /*
  86         * Create the NS announcement service endpoint associated to the RPMsg
  87         * device. The endpoint will be automatically destroyed when the RPMsg
  88         * device will be deleted.
  89         */
  90        ns_ept = rpmsg_create_ept(rpdev, rpmsg_ns_cb, NULL, ns_chinfo);
  91        if (!ns_ept) {
  92                dev_err(&rpdev->dev, "failed to create the ns ept\n");
  93                return -ENOMEM;
  94        }
  95        rpdev->ept = ns_ept;
  96
  97        return 0;
  98}
  99
 100static struct rpmsg_driver rpmsg_ns_driver = {
 101        .drv.name = KBUILD_MODNAME,
 102        .probe = rpmsg_ns_probe,
 103};
 104
 105static int rpmsg_ns_init(void)
 106{
 107        int ret;
 108
 109        ret = register_rpmsg_driver(&rpmsg_ns_driver);
 110        if (ret < 0)
 111                pr_err("%s: Failed to register rpmsg driver\n", __func__);
 112
 113        return ret;
 114}
 115postcore_initcall(rpmsg_ns_init);
 116
 117static void rpmsg_ns_exit(void)
 118{
 119        unregister_rpmsg_driver(&rpmsg_ns_driver);
 120}
 121module_exit(rpmsg_ns_exit);
 122
 123MODULE_DESCRIPTION("Name service announcement rpmsg driver");
 124MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 125MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
 126MODULE_LICENSE("GPL v2");
 127