From: Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>
NCI virtual device simulates a NCI device to the user. It can be used to
validate the NCI module and applications. This driver supports
communication between the virtual NCI device and NCI module.
Signed-off-by: Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>
---
drivers/nfc/Kconfig | 11 ++
drivers/nfc/Makefile | 1 +
drivers/nfc/virtual_ncidev.c | 227 +++++++++++++++++++++++++++++++++++
3 files changed, 239 insertions(+)
create mode 100644 drivers/nfc/virtual_ncidev.c
diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
index 75c65d339018..288c6f1c6979 100644
--- a/drivers/nfc/Kconfig
+++ b/drivers/nfc/Kconfig
@@ -49,6 +49,17 @@ config NFC_PORT100
If unsure, say N.
+config NFC_VIRTUAL_NCI
+ tristate "NCI device simulator driver"
+ depends on NFC_NCI
+ help
+ NCI virtual device simulates a NCI device to the user.
+ It can be used to validate the NCI module and applications.
+ This driver supports communication between the virtual NCI device and
+ module.
+
+ If unsure, say N.
+
source "drivers/nfc/fdp/Kconfig"
source "drivers/nfc/pn544/Kconfig"
source "drivers/nfc/pn533/Kconfig"
diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
index 5393ba59b17d..7b1bfde1d971 100644
--- a/drivers/nfc/Makefile
+++ b/drivers/nfc/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_NFC_ST_NCI) += st-nci/
obj-$(CONFIG_NFC_NXP_NCI) += nxp-nci/
obj-$(CONFIG_NFC_S3FWRN5) += s3fwrn5/
obj-$(CONFIG_NFC_ST95HF) += st95hf/
+obj-$(CONFIG_NFC_VIRTUAL_NCI) += virtual_ncidev.o
diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c
new file mode 100644
index 000000000000..3bd09dfebfe5
--- /dev/null
+++ b/drivers/nfc/virtual_ncidev.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtual NCI device simulation driver
+ *
+ * Copyright (C) 2020 Samsung Electrnoics
+ * Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>
+#include <net/nfc/nci_core.h>
+
+enum virtual_ncidev_mode {
+ virtual_ncidev_enabled,
+ virtual_ncidev_disabled,
+ virtual_ncidev_disabling,
+};
+
+#define IOCTL_GET_NCIDEV_IDX 0
+#define VIRTUAL_NFC_PROTOCOLS (NFC_PROTO_JEWEL_MASK | \
+ NFC_PROTO_MIFARE_MASK | \
+ NFC_PROTO_FELICA_MASK | \
+ NFC_PROTO_ISO14443_MASK | \
+ NFC_PROTO_ISO14443_B_MASK | \
+ NFC_PROTO_ISO15693_MASK)
+
+static enum virtual_ncidev_mode state;
+static struct miscdevice miscdev;
+static struct sk_buff *send_buff;
+static struct nci_dev *ndev;
+static DEFINE_MUTEX(nci_mutex);
+
+static bool virtual_ncidev_check_enabled(void)
+{
+ bool ret = true;
+
+ mutex_lock(&nci_mutex);
+ if (state != virtual_ncidev_enabled)
+ ret = false;
+ mutex_unlock(&nci_mutex);
+
+ return ret;
+}
+
+static int virtual_nci_open(struct nci_dev *ndev)
+{
+ return 0;
+}
+
+static int virtual_nci_close(struct nci_dev *ndev)
+{
+ mutex_lock(&nci_mutex);
+ if (send_buff)
+ kfree_skb(send_buff);
+ send_buff = NULL;
+ mutex_unlock(&nci_mutex);
+
+ return 0;
+}
+
+static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
+{
+ if (virtual_ncidev_check_enabled() == false)
+ return 0;
+
+ mutex_lock(&nci_mutex);
+ if (send_buff) {
+ mutex_unlock(&nci_mutex);
+ return -1;
+ }
+ send_buff = skb_copy(skb, GFP_KERNEL);
+ mutex_unlock(&nci_mutex);
+
+ return 0;
+}
+
+static struct nci_ops virtual_nci_ops = {
+ .open = virtual_nci_open,
+ .close = virtual_nci_close,
+ .send = virtual_nci_send
+};
+
+static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ size_t actual_len;
+
+ mutex_lock(&nci_mutex);
+ if (!send_buff) {
+ mutex_unlock(&nci_mutex);
+ return 0;
+ }
+
+ actual_len = min_t(size_t, count, send_buff->len);
+
+ if (copy_to_user(buf, send_buff->data, actual_len)) {
+ mutex_unlock(&nci_mutex);
+ return -EFAULT;
+ }
+
+ skb_pull(send_buff, actual_len);
+ if (send_buff->len == 0) {
+ consume_skb(send_buff);
+ send_buff = NULL;
+ }
+ mutex_unlock(&nci_mutex);
+
+ return actual_len;
+}
+
+static ssize_t virtual_ncidev_write(struct file *file,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct sk_buff *skb;
+
+ skb = alloc_skb(count, GFP_KERNEL);
+ if (!skb)
+ return -ENOMEM;
+
+ if (copy_from_user(skb_put(skb, count), buf, count)) {
+ kfree_skb(skb);
+ return -EFAULT;
+ }
+
+ nci_recv_frame(ndev, skb);
+ return count;
+}
+
+static int virtual_ncidev_open(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ mutex_lock(&nci_mutex);
+ if (state != virtual_ncidev_disabled) {
+ mutex_unlock(&nci_mutex);
+ return -EBUSY;
+ }
+
+ ndev = nci_allocate_device(&virtual_nci_ops, VIRTUAL_NFC_PROTOCOLS,
+ 0, 0);
+ if (!ndev) {
+ mutex_unlock(&nci_mutex);
+ return -ENOMEM;
+ }
+
+ ret = nci_register_device(ndev);
+ if (ret < 0) {
+ nci_free_device(ndev);
+ mutex_unlock(&nci_mutex);
+ return ret;
+ }
+ state = virtual_ncidev_enabled;
+ mutex_unlock(&nci_mutex);
+
+ return 0;
+}
+
+static int virtual_ncidev_close(struct inode *inode, struct file *file)
+{
+ mutex_lock(&nci_mutex);
+
+ if (state == virtual_ncidev_enabled) {
+ state = virtual_ncidev_disabling;
+ mutex_unlock(&nci_mutex);
+
+ nci_unregister_device(ndev);
+ nci_free_device(ndev);
+
+ mutex_lock(&nci_mutex);
+ }
+
+ state = virtual_ncidev_disabled;
+ mutex_unlock(&nci_mutex);
+
+ return 0;
+}
+
+static long virtual_ncidev_ioctl(struct file *flip, unsigned int cmd,
+ unsigned long arg)
+{
+ if (cmd == IOCTL_GET_NCIDEV_IDX) {
+ struct nfc_dev *nfc_dev = ndev->nfc_dev;
+ void __user *p = (void __user *)arg;
+
+ if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
+ return -EFAULT;
+ } else {
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static const struct file_operations virtual_ncidev_fops = {
+ .owner = THIS_MODULE,
+ .read = virtual_ncidev_read,
+ .write = virtual_ncidev_write,
+ .open = virtual_ncidev_open,
+ .release = virtual_ncidev_close,
+ .unlocked_ioctl = virtual_ncidev_ioctl
+};
+
+static int __init virtual_ncidev_init(void)
+{
+ state = virtual_ncidev_disabled;
+ miscdev.minor = MISC_DYNAMIC_MINOR;
+ miscdev.name = "virtual_nci";
+ miscdev.fops = &virtual_ncidev_fops;
+ miscdev.mode = S_IALLUGO;
+
+ return misc_register(&miscdev);
+}
+
+static void __exit virtual_ncidev_exit(void)
+{
+ misc_deregister(&miscdev);
+}
+
+module_init(virtual_ncidev_init);
+module_exit(virtual_ncidev_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Virtual NCI device simulation driver");
+MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>");
--
2.25.1
