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 */ 21 int 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 } 28 EXPORT_SYMBOL(rpmsg_ns_register_device); 29 30 /* invoked when a name service announcement arrives */ 31 static 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 74 static 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 98 static struct rpmsg_driver rpmsg_ns_driver = { 99 .drv.name = KBUILD_MODNAME, 100 .probe = rpmsg_ns_probe, 101 }; 102 103 static 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 } 113 postcore_initcall(rpmsg_ns_init); 114 115 static void rpmsg_ns_exit(void) 116 { 117 unregister_rpmsg_driver(&rpmsg_ns_driver); 118 } 119 module_exit(rpmsg_ns_exit); 120 121 MODULE_DESCRIPTION("Name service announcement rpmsg driver"); 122 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); 123 MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); 124 MODULE_LICENSE("GPL v2"); 125