1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2022, STMicroelectronics 4 * Copyright (c) 2016, Linaro Ltd. 5 * Copyright (c) 2012, Michal Simek <[email protected]> 6 * Copyright (c) 2012, PetaLogix 7 * Copyright (c) 2011, Texas Instruments, Inc. 8 * Copyright (c) 2011, Google, Inc. 9 * 10 * Based on rpmsg performance statistics driver by Michal Simek, which in turn 11 * was based on TI & Google OMX rpmsg driver. 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/cdev.h> 17 #include <linux/device.h> 18 #include <linux/fs.h> 19 #include <linux/idr.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/rpmsg.h> 23 #include <linux/skbuff.h> 24 #include <linux/slab.h> 25 #include <linux/uaccess.h> 26 #include <uapi/linux/rpmsg.h> 27 28 #include "rpmsg_char.h" 29 #include "rpmsg_internal.h" 30 31 #define RPMSG_DEV_MAX (MINORMASK + 1) 32 33 static dev_t rpmsg_major; 34 35 static DEFINE_IDA(rpmsg_ctrl_ida); 36 static DEFINE_IDA(rpmsg_minor_ida); 37 38 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) 39 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) 40 41 /** 42 * struct rpmsg_ctrldev - control device for instantiating endpoint devices 43 * @rpdev: underlaying rpmsg device 44 * @cdev: cdev for the ctrl device 45 * @dev: device for the ctrl device 46 */ 47 struct rpmsg_ctrldev { 48 struct rpmsg_device *rpdev; 49 struct cdev cdev; 50 struct device dev; 51 }; 52 53 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) 54 { 55 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 56 57 get_device(&ctrldev->dev); 58 filp->private_data = ctrldev; 59 60 return 0; 61 } 62 63 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) 64 { 65 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 66 67 put_device(&ctrldev->dev); 68 69 return 0; 70 } 71 72 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, 73 unsigned long arg) 74 { 75 struct rpmsg_ctrldev *ctrldev = fp->private_data; 76 void __user *argp = (void __user *)arg; 77 struct rpmsg_endpoint_info eptinfo; 78 struct rpmsg_channel_info chinfo; 79 80 if (cmd != RPMSG_CREATE_EPT_IOCTL) 81 return -EINVAL; 82 83 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) 84 return -EFAULT; 85 86 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); 87 chinfo.name[RPMSG_NAME_SIZE - 1] = '\0'; 88 chinfo.src = eptinfo.src; 89 chinfo.dst = eptinfo.dst; 90 91 return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); 92 }; 93 94 static const struct file_operations rpmsg_ctrldev_fops = { 95 .owner = THIS_MODULE, 96 .open = rpmsg_ctrldev_open, 97 .release = rpmsg_ctrldev_release, 98 .unlocked_ioctl = rpmsg_ctrldev_ioctl, 99 .compat_ioctl = compat_ptr_ioctl, 100 }; 101 102 static void rpmsg_ctrldev_release_device(struct device *dev) 103 { 104 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); 105 106 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 107 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 108 kfree(ctrldev); 109 } 110 111 static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) 112 { 113 struct rpmsg_ctrldev *ctrldev; 114 struct device *dev; 115 int ret; 116 117 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); 118 if (!ctrldev) 119 return -ENOMEM; 120 121 ctrldev->rpdev = rpdev; 122 123 dev = &ctrldev->dev; 124 device_initialize(dev); 125 dev->parent = &rpdev->dev; 126 dev->class = rpmsg_class; 127 128 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); 129 ctrldev->cdev.owner = THIS_MODULE; 130 131 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 132 if (ret < 0) 133 goto free_ctrldev; 134 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 135 136 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); 137 if (ret < 0) 138 goto free_minor_ida; 139 dev->id = ret; 140 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); 141 142 ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev); 143 if (ret) 144 goto free_ctrl_ida; 145 146 /* We can now rely on the release function for cleanup */ 147 dev->release = rpmsg_ctrldev_release_device; 148 149 dev_set_drvdata(&rpdev->dev, ctrldev); 150 151 return ret; 152 153 free_ctrl_ida: 154 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 155 free_minor_ida: 156 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 157 free_ctrldev: 158 put_device(dev); 159 kfree(ctrldev); 160 161 return ret; 162 } 163 164 static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev) 165 { 166 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); 167 int ret; 168 169 /* Destroy all endpoints */ 170 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy); 171 if (ret) 172 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); 173 174 cdev_device_del(&ctrldev->cdev, &ctrldev->dev); 175 put_device(&ctrldev->dev); 176 } 177 178 static struct rpmsg_driver rpmsg_ctrldev_driver = { 179 .probe = rpmsg_ctrldev_probe, 180 .remove = rpmsg_ctrldev_remove, 181 .drv = { 182 .name = "rpmsg_ctrl", 183 }, 184 }; 185 186 static int rpmsg_ctrldev_init(void) 187 { 188 int ret; 189 190 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl"); 191 if (ret < 0) { 192 pr_err("failed to allocate char dev region\n"); 193 return ret; 194 } 195 196 ret = register_rpmsg_driver(&rpmsg_ctrldev_driver); 197 if (ret < 0) { 198 pr_err("failed to register rpmsg driver\n"); 199 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 200 } 201 202 return ret; 203 } 204 postcore_initcall(rpmsg_ctrldev_init); 205 206 static void rpmsg_ctrldev_exit(void) 207 { 208 unregister_rpmsg_driver(&rpmsg_ctrldev_driver); 209 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 210 } 211 module_exit(rpmsg_ctrldev_exit); 212 213 MODULE_DESCRIPTION("rpmsg control interface"); 214 MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); 215 MODULE_LICENSE("GPL v2"); 216