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124 lines · 3.2 KiB

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 rpdev->src = RPMSG_NS_ADDR;
24 rpdev->dst = RPMSG_NS_ADDR;
25
26 return rpmsg_register_device_override(rpdev, "rpmsg_ns");
27}
28EXPORT_SYMBOL(rpmsg_ns_register_device);
29
30/* invoked when a name service announcement arrives */
31static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
32 void *priv, u32 src)
33{
34 struct rpmsg_ns_msg *msg = data;
35 struct rpmsg_device *newch;
36 struct rpmsg_channel_info chinfo;
37 struct device *dev = rpdev->dev.parent;
38 int ret;
39
40#if defined(CONFIG_DYNAMIC_DEBUG)
41 dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
42 data, len, true);
43#endif
44
45 if (len != sizeof(*msg)) {
46 dev_err(dev, "malformed ns msg (%d)\n", len);
47 return -EINVAL;
48 }
49
50 /* don't trust the remote processor for null terminating the name */
51 msg->name[RPMSG_NAME_SIZE - 1] = '\0';
52
53 strscpy_pad(chinfo.name, msg->name, sizeof(chinfo.name));
54 chinfo.src = RPMSG_ADDR_ANY;
55 chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr);
56
57 dev_info(dev, "%sing channel %s addr 0x%x\n",
58 rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY ?
59 "destroy" : "creat", msg->name, chinfo.dst);
60
61 if (rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY) {
62 ret = rpmsg_release_channel(rpdev, &chinfo);
63 if (ret)
64 dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
65 } else {
66 newch = rpmsg_create_channel(rpdev, &chinfo);
67 if (!newch)
68 dev_err(dev, "rpmsg_create_channel failed\n");
69 }
70
71 return 0;
72}
73
74static int rpmsg_ns_probe(struct rpmsg_device *rpdev)
75{
76 struct rpmsg_endpoint *ns_ept;
77 struct rpmsg_channel_info ns_chinfo = {
78 .src = RPMSG_NS_ADDR,
79 .dst = RPMSG_NS_ADDR,
80 .name = "name_service",
81 };
82
83 /*
84 * Create the NS announcement service endpoint associated to the RPMsg
85 * device. The endpoint will be automatically destroyed when the RPMsg
86 * device will be deleted.
87 */
88 ns_ept = rpmsg_create_ept(rpdev, rpmsg_ns_cb, NULL, ns_chinfo);
89 if (!ns_ept) {
90 dev_err(&rpdev->dev, "failed to create the ns ept\n");
91 return -ENOMEM;
92 }
93 rpdev->ept = ns_ept;
94
95 return 0;
96}
97
98static struct rpmsg_driver rpmsg_ns_driver = {
99 .drv.name = KBUILD_MODNAME,
100 .probe = rpmsg_ns_probe,
101};
102
103static int rpmsg_ns_init(void)
104{
105 int ret;
106
107 ret = register_rpmsg_driver(&rpmsg_ns_driver);
108 if (ret < 0)
109 pr_err("%s: Failed to register rpmsg driver\n", __func__);
110
111 return ret;
112}
113postcore_initcall(rpmsg_ns_init);
114
115static void rpmsg_ns_exit(void)
116{
117 unregister_rpmsg_driver(&rpmsg_ns_driver);
118}
119module_exit(rpmsg_ns_exit);
120
121MODULE_DESCRIPTION("Name service announcement rpmsg driver");
122MODULE_AUTHOR("Arnaud Pouliquen <[email protected]>");
123MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
124MODULE_LICENSE("GPL v2");