495 строки
11 KiB
C
495 строки
11 KiB
C
|
/*
|
||
|
* Copyright (C) 2015, Marvell International Ltd.
|
||
|
*
|
||
|
* This software file (the "File") is distributed by Marvell International
|
||
|
* Ltd. under the terms of the GNU General Public License Version 2, June 1991
|
||
|
* (the "License"). You may use, redistribute and/or modify this File in
|
||
|
* accordance with the terms and conditions of the License, a copy of which
|
||
|
* is available on the worldwide web at
|
||
|
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
|
||
|
*
|
||
|
* THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
|
||
|
* IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
|
||
|
* ARE EXPRESSLY DISCLAIMED. The License provides additional details about
|
||
|
* this warranty disclaimer.
|
||
|
*/
|
||
|
|
||
|
/* Inspired (hugely) by HCI LDISC implementation in Bluetooth.
|
||
|
*
|
||
|
* Copyright (C) 2000-2001 Qualcomm Incorporated
|
||
|
* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
|
||
|
* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
|
||
|
*/
|
||
|
|
||
|
#include <linux/module.h>
|
||
|
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/types.h>
|
||
|
#include <linux/fcntl.h>
|
||
|
#include <linux/interrupt.h>
|
||
|
#include <linux/ptrace.h>
|
||
|
#include <linux/poll.h>
|
||
|
|
||
|
#include <linux/slab.h>
|
||
|
#include <linux/tty.h>
|
||
|
#include <linux/errno.h>
|
||
|
#include <linux/string.h>
|
||
|
#include <linux/signal.h>
|
||
|
#include <linux/ioctl.h>
|
||
|
#include <linux/skbuff.h>
|
||
|
|
||
|
#include <net/nfc/nci.h>
|
||
|
#include <net/nfc/nci_core.h>
|
||
|
|
||
|
/* TX states */
|
||
|
#define NCI_UART_SENDING 1
|
||
|
#define NCI_UART_TX_WAKEUP 2
|
||
|
|
||
|
static struct nci_uart *nci_uart_drivers[NCI_UART_DRIVER_MAX];
|
||
|
|
||
|
static inline struct sk_buff *nci_uart_dequeue(struct nci_uart *nu)
|
||
|
{
|
||
|
struct sk_buff *skb = nu->tx_skb;
|
||
|
|
||
|
if (!skb)
|
||
|
skb = skb_dequeue(&nu->tx_q);
|
||
|
else
|
||
|
nu->tx_skb = NULL;
|
||
|
|
||
|
return skb;
|
||
|
}
|
||
|
|
||
|
static inline int nci_uart_queue_empty(struct nci_uart *nu)
|
||
|
{
|
||
|
if (nu->tx_skb)
|
||
|
return 0;
|
||
|
|
||
|
return skb_queue_empty(&nu->tx_q);
|
||
|
}
|
||
|
|
||
|
static int nci_uart_tx_wakeup(struct nci_uart *nu)
|
||
|
{
|
||
|
if (test_and_set_bit(NCI_UART_SENDING, &nu->tx_state)) {
|
||
|
set_bit(NCI_UART_TX_WAKEUP, &nu->tx_state);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
schedule_work(&nu->write_work);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void nci_uart_write_work(struct work_struct *work)
|
||
|
{
|
||
|
struct nci_uart *nu = container_of(work, struct nci_uart, write_work);
|
||
|
struct tty_struct *tty = nu->tty;
|
||
|
struct sk_buff *skb;
|
||
|
|
||
|
restart:
|
||
|
clear_bit(NCI_UART_TX_WAKEUP, &nu->tx_state);
|
||
|
|
||
|
if (nu->ops.tx_start)
|
||
|
nu->ops.tx_start(nu);
|
||
|
|
||
|
while ((skb = nci_uart_dequeue(nu))) {
|
||
|
int len;
|
||
|
|
||
|
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
|
||
|
len = tty->ops->write(tty, skb->data, skb->len);
|
||
|
skb_pull(skb, len);
|
||
|
if (skb->len) {
|
||
|
nu->tx_skb = skb;
|
||
|
break;
|
||
|
}
|
||
|
kfree_skb(skb);
|
||
|
}
|
||
|
|
||
|
if (test_bit(NCI_UART_TX_WAKEUP, &nu->tx_state))
|
||
|
goto restart;
|
||
|
|
||
|
if (nu->ops.tx_done && nci_uart_queue_empty(nu))
|
||
|
nu->ops.tx_done(nu);
|
||
|
|
||
|
clear_bit(NCI_UART_SENDING, &nu->tx_state);
|
||
|
}
|
||
|
|
||
|
static int nci_uart_set_driver(struct tty_struct *tty, unsigned int driver)
|
||
|
{
|
||
|
struct nci_uart *nu = NULL;
|
||
|
int ret;
|
||
|
|
||
|
if (driver >= NCI_UART_DRIVER_MAX)
|
||
|
return -EINVAL;
|
||
|
|
||
|
if (!nci_uart_drivers[driver])
|
||
|
return -ENOENT;
|
||
|
|
||
|
nu = kzalloc(sizeof(*nu), GFP_KERNEL);
|
||
|
if (!nu)
|
||
|
return -ENOMEM;
|
||
|
|
||
|
memcpy(nu, nci_uart_drivers[driver], sizeof(struct nci_uart));
|
||
|
nu->tty = tty;
|
||
|
tty->disc_data = nu;
|
||
|
skb_queue_head_init(&nu->tx_q);
|
||
|
INIT_WORK(&nu->write_work, nci_uart_write_work);
|
||
|
spin_lock_init(&nu->rx_lock);
|
||
|
|
||
|
ret = nu->ops.open(nu);
|
||
|
if (ret) {
|
||
|
tty->disc_data = NULL;
|
||
|
kfree(nu);
|
||
|
} else if (!try_module_get(nu->owner)) {
|
||
|
nu->ops.close(nu);
|
||
|
tty->disc_data = NULL;
|
||
|
kfree(nu);
|
||
|
return -ENOENT;
|
||
|
}
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* ------ LDISC part ------ */
|
||
|
|
||
|
/* nci_uart_tty_open
|
||
|
*
|
||
|
* Called when line discipline changed to NCI_UART.
|
||
|
*
|
||
|
* Arguments:
|
||
|
* tty pointer to tty info structure
|
||
|
* Return Value:
|
||
|
* 0 if success, otherwise error code
|
||
|
*/
|
||
|
static int nci_uart_tty_open(struct tty_struct *tty)
|
||
|
{
|
||
|
/* Error if the tty has no write op instead of leaving an exploitable
|
||
|
* hole
|
||
|
*/
|
||
|
if (!tty->ops->write)
|
||
|
return -EOPNOTSUPP;
|
||
|
|
||
|
tty->disc_data = NULL;
|
||
|
tty->receive_room = 65536;
|
||
|
|
||
|
/* Flush any pending characters in the driver and line discipline. */
|
||
|
|
||
|
/* FIXME: why is this needed. Note don't use ldisc_ref here as the
|
||
|
* open path is before the ldisc is referencable.
|
||
|
*/
|
||
|
|
||
|
if (tty->ldisc->ops->flush_buffer)
|
||
|
tty->ldisc->ops->flush_buffer(tty);
|
||
|
tty_driver_flush_buffer(tty);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* nci_uart_tty_close()
|
||
|
*
|
||
|
* Called when the line discipline is changed to something
|
||
|
* else, the tty is closed, or the tty detects a hangup.
|
||
|
*/
|
||
|
static void nci_uart_tty_close(struct tty_struct *tty)
|
||
|
{
|
||
|
struct nci_uart *nu = (void *)tty->disc_data;
|
||
|
|
||
|
/* Detach from the tty */
|
||
|
tty->disc_data = NULL;
|
||
|
|
||
|
if (!nu)
|
||
|
return;
|
||
|
|
||
|
if (nu->tx_skb)
|
||
|
kfree_skb(nu->tx_skb);
|
||
|
if (nu->rx_skb)
|
||
|
kfree_skb(nu->rx_skb);
|
||
|
|
||
|
skb_queue_purge(&nu->tx_q);
|
||
|
|
||
|
nu->ops.close(nu);
|
||
|
nu->tty = NULL;
|
||
|
module_put(nu->owner);
|
||
|
|
||
|
cancel_work_sync(&nu->write_work);
|
||
|
|
||
|
kfree(nu);
|
||
|
}
|
||
|
|
||
|
/* nci_uart_tty_wakeup()
|
||
|
*
|
||
|
* Callback for transmit wakeup. Called when low level
|
||
|
* device driver can accept more send data.
|
||
|
*
|
||
|
* Arguments: tty pointer to associated tty instance data
|
||
|
* Return Value: None
|
||
|
*/
|
||
|
static void nci_uart_tty_wakeup(struct tty_struct *tty)
|
||
|
{
|
||
|
struct nci_uart *nu = (void *)tty->disc_data;
|
||
|
|
||
|
if (!nu)
|
||
|
return;
|
||
|
|
||
|
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
|
||
|
|
||
|
if (tty != nu->tty)
|
||
|
return;
|
||
|
|
||
|
nci_uart_tx_wakeup(nu);
|
||
|
}
|
||
|
|
||
|
/* nci_uart_tty_receive()
|
||
|
*
|
||
|
* Called by tty low level driver when receive data is
|
||
|
* available.
|
||
|
*
|
||
|
* Arguments: tty pointer to tty isntance data
|
||
|
* data pointer to received data
|
||
|
* flags pointer to flags for data
|
||
|
* count count of received data in bytes
|
||
|
*
|
||
|
* Return Value: None
|
||
|
*/
|
||
|
static void nci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
|
||
|
char *flags, int count)
|
||
|
{
|
||
|
struct nci_uart *nu = (void *)tty->disc_data;
|
||
|
|
||
|
if (!nu || tty != nu->tty)
|
||
|
return;
|
||
|
|
||
|
spin_lock(&nu->rx_lock);
|
||
|
nu->ops.recv_buf(nu, (void *)data, flags, count);
|
||
|
spin_unlock(&nu->rx_lock);
|
||
|
|
||
|
tty_unthrottle(tty);
|
||
|
}
|
||
|
|
||
|
/* nci_uart_tty_ioctl()
|
||
|
*
|
||
|
* Process IOCTL system call for the tty device.
|
||
|
*
|
||
|
* Arguments:
|
||
|
*
|
||
|
* tty pointer to tty instance data
|
||
|
* file pointer to open file object for device
|
||
|
* cmd IOCTL command code
|
||
|
* arg argument for IOCTL call (cmd dependent)
|
||
|
*
|
||
|
* Return Value: Command dependent
|
||
|
*/
|
||
|
static int nci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
|
||
|
unsigned int cmd, unsigned long arg)
|
||
|
{
|
||
|
struct nci_uart *nu = (void *)tty->disc_data;
|
||
|
int err = 0;
|
||
|
|
||
|
switch (cmd) {
|
||
|
case NCIUARTSETDRIVER:
|
||
|
if (!nu)
|
||
|
return nci_uart_set_driver(tty, (unsigned int)arg);
|
||
|
else
|
||
|
return -EBUSY;
|
||
|
break;
|
||
|
default:
|
||
|
err = n_tty_ioctl_helper(tty, file, cmd, arg);
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
/* We don't provide read/write/poll interface for user space. */
|
||
|
static ssize_t nci_uart_tty_read(struct tty_struct *tty, struct file *file,
|
||
|
unsigned char __user *buf, size_t nr)
|
||
|
{
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static ssize_t nci_uart_tty_write(struct tty_struct *tty, struct file *file,
|
||
|
const unsigned char *data, size_t count)
|
||
|
{
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static unsigned int nci_uart_tty_poll(struct tty_struct *tty,
|
||
|
struct file *filp, poll_table *wait)
|
||
|
{
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int nci_uart_send(struct nci_uart *nu, struct sk_buff *skb)
|
||
|
{
|
||
|
/* Queue TX packet */
|
||
|
skb_queue_tail(&nu->tx_q, skb);
|
||
|
|
||
|
/* Try to start TX (if possible) */
|
||
|
nci_uart_tx_wakeup(nu);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* -- Default recv_buf handler --
|
||
|
*
|
||
|
* This handler supposes that NCI frames are sent over UART link without any
|
||
|
* framing. It reads NCI header, retrieve the packet size and once all packet
|
||
|
* bytes are received it passes it to nci_uart driver for processing.
|
||
|
*/
|
||
|
static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data,
|
||
|
char *flags, int count)
|
||
|
{
|
||
|
int chunk_len;
|
||
|
|
||
|
if (!nu->ndev) {
|
||
|
nfc_err(nu->tty->dev,
|
||
|
"receive data from tty but no NCI dev is attached yet, drop buffer\n");
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Decode all incoming data in packets
|
||
|
* and enqueue then for processing.
|
||
|
*/
|
||
|
while (count > 0) {
|
||
|
/* If this is the first data of a packet, allocate a buffer */
|
||
|
if (!nu->rx_skb) {
|
||
|
nu->rx_packet_len = -1;
|
||
|
nu->rx_skb = nci_skb_alloc(nu->ndev,
|
||
|
NCI_MAX_PACKET_SIZE,
|
||
|
GFP_KERNEL);
|
||
|
if (!nu->rx_skb)
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
/* Eat byte after byte till full packet header is received */
|
||
|
if (nu->rx_skb->len < NCI_CTRL_HDR_SIZE) {
|
||
|
*skb_put(nu->rx_skb, 1) = *data++;
|
||
|
--count;
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
/* Header was received but packet len was not read */
|
||
|
if (nu->rx_packet_len < 0)
|
||
|
nu->rx_packet_len = NCI_CTRL_HDR_SIZE +
|
||
|
nci_plen(nu->rx_skb->data);
|
||
|
|
||
|
/* Compute how many bytes are missing and how many bytes can
|
||
|
* be consumed.
|
||
|
*/
|
||
|
chunk_len = nu->rx_packet_len - nu->rx_skb->len;
|
||
|
if (count < chunk_len)
|
||
|
chunk_len = count;
|
||
|
memcpy(skb_put(nu->rx_skb, chunk_len), data, chunk_len);
|
||
|
data += chunk_len;
|
||
|
count -= chunk_len;
|
||
|
|
||
|
/* Chcek if packet is fully received */
|
||
|
if (nu->rx_packet_len == nu->rx_skb->len) {
|
||
|
/* Pass RX packet to driver */
|
||
|
if (nu->ops.recv(nu, nu->rx_skb) != 0)
|
||
|
nfc_err(nu->tty->dev, "corrupted RX packet\n");
|
||
|
/* Next packet will be a new one */
|
||
|
nu->rx_skb = NULL;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* -- Default recv handler -- */
|
||
|
static int nci_uart_default_recv(struct nci_uart *nu, struct sk_buff *skb)
|
||
|
{
|
||
|
return nci_recv_frame(nu->ndev, skb);
|
||
|
}
|
||
|
|
||
|
int nci_uart_register(struct nci_uart *nu)
|
||
|
{
|
||
|
if (!nu || !nu->ops.open ||
|
||
|
!nu->ops.recv || !nu->ops.close)
|
||
|
return -EINVAL;
|
||
|
|
||
|
/* Set the send callback */
|
||
|
nu->ops.send = nci_uart_send;
|
||
|
|
||
|
/* Install default handlers if not overridden */
|
||
|
if (!nu->ops.recv_buf)
|
||
|
nu->ops.recv_buf = nci_uart_default_recv_buf;
|
||
|
if (!nu->ops.recv)
|
||
|
nu->ops.recv = nci_uart_default_recv;
|
||
|
|
||
|
/* Add this driver in the driver list */
|
||
|
if (!nci_uart_drivers[nu->driver]) {
|
||
|
pr_err("driver %d is already registered\n", nu->driver);
|
||
|
return -EBUSY;
|
||
|
}
|
||
|
nci_uart_drivers[nu->driver] = nu;
|
||
|
|
||
|
pr_info("NCI uart driver '%s [%d]' registered\n", nu->name, nu->driver);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(nci_uart_register);
|
||
|
|
||
|
void nci_uart_unregister(struct nci_uart *nu)
|
||
|
{
|
||
|
pr_info("NCI uart driver '%s [%d]' unregistered\n", nu->name,
|
||
|
nu->driver);
|
||
|
|
||
|
/* Remove this driver from the driver list */
|
||
|
nci_uart_drivers[nu->driver] = NULL;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(nci_uart_unregister);
|
||
|
|
||
|
void nci_uart_set_config(struct nci_uart *nu, int baudrate, int flow_ctrl)
|
||
|
{
|
||
|
struct ktermios new_termios;
|
||
|
|
||
|
if (!nu->tty)
|
||
|
return;
|
||
|
|
||
|
down_read(&nu->tty->termios_rwsem);
|
||
|
new_termios = nu->tty->termios;
|
||
|
up_read(&nu->tty->termios_rwsem);
|
||
|
tty_termios_encode_baud_rate(&new_termios, baudrate, baudrate);
|
||
|
|
||
|
if (flow_ctrl)
|
||
|
new_termios.c_cflag |= CRTSCTS;
|
||
|
else
|
||
|
new_termios.c_cflag &= ~CRTSCTS;
|
||
|
|
||
|
tty_set_termios(nu->tty, &new_termios);
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(nci_uart_set_config);
|
||
|
|
||
|
static struct tty_ldisc_ops nci_uart_ldisc = {
|
||
|
.magic = TTY_LDISC_MAGIC,
|
||
|
.owner = THIS_MODULE,
|
||
|
.name = "n_nci",
|
||
|
.open = nci_uart_tty_open,
|
||
|
.close = nci_uart_tty_close,
|
||
|
.read = nci_uart_tty_read,
|
||
|
.write = nci_uart_tty_write,
|
||
|
.poll = nci_uart_tty_poll,
|
||
|
.receive_buf = nci_uart_tty_receive,
|
||
|
.write_wakeup = nci_uart_tty_wakeup,
|
||
|
.ioctl = nci_uart_tty_ioctl,
|
||
|
};
|
||
|
|
||
|
static int __init nci_uart_init(void)
|
||
|
{
|
||
|
memset(nci_uart_drivers, 0, sizeof(nci_uart_drivers));
|
||
|
return tty_register_ldisc(N_NCI, &nci_uart_ldisc);
|
||
|
}
|
||
|
|
||
|
static void __exit nci_uart_exit(void)
|
||
|
{
|
||
|
tty_unregister_ldisc(N_NCI);
|
||
|
}
|
||
|
|
||
|
module_init(nci_uart_init);
|
||
|
module_exit(nci_uart_exit);
|
||
|
|
||
|
MODULE_AUTHOR("Marvell International Ltd.");
|
||
|
MODULE_DESCRIPTION("NFC NCI UART driver");
|
||
|
MODULE_LICENSE("GPL");
|
||
|
MODULE_ALIAS_LDISC(N_NCI);
|