1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Virtual NCI device simulation driver
5 * Copyright (C) 2020 Samsung Electrnoics
6 * Bongsu Jeon <bongsu.jeon@samsung.com>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/miscdevice.h>
12 #include <linux/mutex.h>
13 #include <linux/wait.h>
14 #include <net/nfc/nci_core.h>
16 #define IOCTL_GET_NCIDEV_IDX 0
17 #define VIRTUAL_NFC_PROTOCOLS (NFC_PROTO_JEWEL_MASK | \
18 NFC_PROTO_MIFARE_MASK | \
19 NFC_PROTO_FELICA_MASK | \
20 NFC_PROTO_ISO14443_MASK | \
21 NFC_PROTO_ISO14443_B_MASK | \
22 NFC_PROTO_ISO15693_MASK)
24 struct virtual_nci_dev {
27 struct sk_buff *send_buff;
28 struct wait_queue_head wq;
32 static int virtual_nci_open(struct nci_dev *ndev)
34 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
40 static int virtual_nci_close(struct nci_dev *ndev)
42 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
44 mutex_lock(&vdev->mtx);
45 kfree_skb(vdev->send_buff);
46 vdev->send_buff = NULL;
47 vdev->running = false;
48 mutex_unlock(&vdev->mtx);
53 static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
55 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
57 mutex_lock(&vdev->mtx);
58 if (vdev->send_buff || !vdev->running) {
59 mutex_unlock(&vdev->mtx);
63 vdev->send_buff = skb_copy(skb, GFP_KERNEL);
64 if (!vdev->send_buff) {
65 mutex_unlock(&vdev->mtx);
69 mutex_unlock(&vdev->mtx);
70 wake_up_interruptible(&vdev->wq);
76 static const struct nci_ops virtual_nci_ops = {
77 .open = virtual_nci_open,
78 .close = virtual_nci_close,
79 .send = virtual_nci_send
82 static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
83 size_t count, loff_t *ppos)
85 struct virtual_nci_dev *vdev = file->private_data;
88 mutex_lock(&vdev->mtx);
89 while (!vdev->send_buff) {
90 mutex_unlock(&vdev->mtx);
91 if (wait_event_interruptible(vdev->wq, vdev->send_buff))
93 mutex_lock(&vdev->mtx);
96 actual_len = min_t(size_t, count, vdev->send_buff->len);
98 if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
99 mutex_unlock(&vdev->mtx);
103 skb_pull(vdev->send_buff, actual_len);
104 if (vdev->send_buff->len == 0) {
105 consume_skb(vdev->send_buff);
106 vdev->send_buff = NULL;
108 mutex_unlock(&vdev->mtx);
113 static ssize_t virtual_ncidev_write(struct file *file,
114 const char __user *buf,
115 size_t count, loff_t *ppos)
117 struct virtual_nci_dev *vdev = file->private_data;
120 skb = alloc_skb(count, GFP_KERNEL);
124 if (copy_from_user(skb_put(skb, count), buf, count)) {
129 nci_recv_frame(vdev->ndev, skb);
133 static int virtual_ncidev_open(struct inode *inode, struct file *file)
136 struct virtual_nci_dev *vdev;
138 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
141 vdev->ndev = nci_allocate_device(&virtual_nci_ops,
142 VIRTUAL_NFC_PROTOCOLS, 0, 0);
148 mutex_init(&vdev->mtx);
149 init_waitqueue_head(&vdev->wq);
150 file->private_data = vdev;
151 nci_set_drvdata(vdev->ndev, vdev);
153 ret = nci_register_device(vdev->ndev);
155 nci_free_device(vdev->ndev);
156 mutex_destroy(&vdev->mtx);
164 static int virtual_ncidev_close(struct inode *inode, struct file *file)
166 struct virtual_nci_dev *vdev = file->private_data;
168 nci_unregister_device(vdev->ndev);
169 nci_free_device(vdev->ndev);
170 mutex_destroy(&vdev->mtx);
176 static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
179 struct virtual_nci_dev *vdev = file->private_data;
180 const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
181 void __user *p = (void __user *)arg;
183 if (cmd != IOCTL_GET_NCIDEV_IDX)
186 if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
192 static const struct file_operations virtual_ncidev_fops = {
193 .owner = THIS_MODULE,
194 .read = virtual_ncidev_read,
195 .write = virtual_ncidev_write,
196 .open = virtual_ncidev_open,
197 .release = virtual_ncidev_close,
198 .unlocked_ioctl = virtual_ncidev_ioctl
201 static struct miscdevice miscdev = {
202 .minor = MISC_DYNAMIC_MINOR,
203 .name = "virtual_nci",
204 .fops = &virtual_ncidev_fops,
208 module_misc_device(miscdev);
210 MODULE_LICENSE("GPL");
211 MODULE_DESCRIPTION("Virtual NCI device simulation driver");
212 MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");