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linux-next/drivers/bluetooth/hci_ldisc.c
Ilya Faenson 2a973dfada Bluetooth: hci_uart: Add new line discipline enhancements
Added the ability to flow control the UART, improved the UART baud
rate setting, transferred the speeds into line discipline from the
protocol and introduced the tty init function.

Signed-off-by: Ilya Faenson <ifaenson@broadcom.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2015-06-17 23:44:49 +02:00

851 lines
18 KiB
C

/*
*
* Bluetooth HCI UART driver
*
* Copyright (C) 2000-2001 Qualcomm Incorporated
* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#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 <linux/firmware.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include "btintel.h"
#include "btbcm.h"
#include "hci_uart.h"
#define VERSION "2.3"
static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
int hci_uart_register_proto(const struct hci_uart_proto *p)
{
if (p->id >= HCI_UART_MAX_PROTO)
return -EINVAL;
if (hup[p->id])
return -EEXIST;
hup[p->id] = p;
BT_INFO("HCI UART protocol %s registered", p->name);
return 0;
}
int hci_uart_unregister_proto(const struct hci_uart_proto *p)
{
if (p->id >= HCI_UART_MAX_PROTO)
return -EINVAL;
if (!hup[p->id])
return -EINVAL;
hup[p->id] = NULL;
return 0;
}
static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
{
if (id >= HCI_UART_MAX_PROTO)
return NULL;
return hup[id];
}
static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
{
struct hci_dev *hdev = hu->hdev;
/* Update HCI stat counters */
switch (pkt_type) {
case HCI_COMMAND_PKT:
hdev->stat.cmd_tx++;
break;
case HCI_ACLDATA_PKT:
hdev->stat.acl_tx++;
break;
case HCI_SCODATA_PKT:
hdev->stat.sco_tx++;
break;
}
}
static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
{
struct sk_buff *skb = hu->tx_skb;
if (!skb)
skb = hu->proto->dequeue(hu);
else
hu->tx_skb = NULL;
return skb;
}
int hci_uart_tx_wakeup(struct hci_uart *hu)
{
if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
return 0;
}
BT_DBG("");
schedule_work(&hu->write_work);
return 0;
}
static void hci_uart_write_work(struct work_struct *work)
{
struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
struct tty_struct *tty = hu->tty;
struct hci_dev *hdev = hu->hdev;
struct sk_buff *skb;
/* REVISIT: should we cope with bad skbs or ->write() returning
* and error value ?
*/
restart:
clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
while ((skb = hci_uart_dequeue(hu))) {
int len;
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
len = tty->ops->write(tty, skb->data, skb->len);
hdev->stat.byte_tx += len;
skb_pull(skb, len);
if (skb->len) {
hu->tx_skb = skb;
break;
}
hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
kfree_skb(skb);
}
if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
goto restart;
clear_bit(HCI_UART_SENDING, &hu->tx_state);
}
static void hci_uart_init_work(struct work_struct *work)
{
struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
int err;
if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
return;
err = hci_register_dev(hu->hdev);
if (err < 0) {
BT_ERR("Can't register HCI device");
hci_free_dev(hu->hdev);
hu->hdev = NULL;
hu->proto->close(hu);
}
set_bit(HCI_UART_REGISTERED, &hu->flags);
}
int hci_uart_init_ready(struct hci_uart *hu)
{
if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
return -EALREADY;
schedule_work(&hu->init_ready);
return 0;
}
/* ------- Interface to HCI layer ------ */
/* Initialize device */
static int hci_uart_open(struct hci_dev *hdev)
{
BT_DBG("%s %p", hdev->name, hdev);
/* Nothing to do for UART driver */
set_bit(HCI_RUNNING, &hdev->flags);
return 0;
}
/* Reset device */
static int hci_uart_flush(struct hci_dev *hdev)
{
struct hci_uart *hu = hci_get_drvdata(hdev);
struct tty_struct *tty = hu->tty;
BT_DBG("hdev %p tty %p", hdev, tty);
if (hu->tx_skb) {
kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
}
/* Flush any pending characters in the driver and discipline. */
tty_ldisc_flush(tty);
tty_driver_flush_buffer(tty);
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
hu->proto->flush(hu);
return 0;
}
/* Close device */
static int hci_uart_close(struct hci_dev *hdev)
{
BT_DBG("hdev %p", hdev);
if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
return 0;
hci_uart_flush(hdev);
hdev->flush = NULL;
return 0;
}
/* Send frames from HCI layer */
static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
struct hci_uart *hu = hci_get_drvdata(hdev);
if (!test_bit(HCI_RUNNING, &hdev->flags))
return -EBUSY;
BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
hu->proto->enqueue(hu, skb);
hci_uart_tx_wakeup(hu);
return 0;
}
/* Flow control or un-flow control the device */
void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
{
struct tty_struct *tty = hu->tty;
struct ktermios ktermios;
int status;
unsigned int set = 0;
unsigned int clear = 0;
if (enable) {
/* Disable hardware flow control */
ktermios = tty->termios;
ktermios.c_cflag &= ~CRTSCTS;
status = tty_set_termios(tty, &ktermios);
BT_DBG("Disabling hardware flow control: %s",
status ? "failed" : "success");
/* Clear RTS to prevent the device from sending */
/* Most UARTs need OUT2 to enable interrupts */
status = tty->driver->ops->tiocmget(tty);
BT_DBG("Current tiocm 0x%x", status);
set &= ~(TIOCM_OUT2 | TIOCM_RTS);
clear = ~set;
set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
TIOCM_OUT2 | TIOCM_LOOP;
clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
TIOCM_OUT2 | TIOCM_LOOP;
status = tty->driver->ops->tiocmset(tty, set, clear);
BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
} else {
/* Set RTS to allow the device to send again */
status = tty->driver->ops->tiocmget(tty);
BT_DBG("Current tiocm 0x%x", status);
set |= (TIOCM_OUT2 | TIOCM_RTS);
clear = ~set;
set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
TIOCM_OUT2 | TIOCM_LOOP;
clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
TIOCM_OUT2 | TIOCM_LOOP;
status = tty->driver->ops->tiocmset(tty, set, clear);
BT_DBG("Setting RTS: %s", status ? "failed" : "success");
/* Re-enable hardware flow control */
ktermios = tty->termios;
ktermios.c_cflag |= CRTSCTS;
status = tty_set_termios(tty, &ktermios);
BT_DBG("Enabling hardware flow control: %s",
status ? "failed" : "success");
}
}
void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
unsigned int oper_speed)
{
hu->init_speed = init_speed;
hu->oper_speed = oper_speed;
}
void hci_uart_init_tty(struct hci_uart *hu)
{
struct tty_struct *tty = hu->tty;
struct ktermios ktermios;
/* Bring the UART into a known 8 bits no parity hw fc state */
ktermios = tty->termios;
ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
INLCR | IGNCR | ICRNL | IXON);
ktermios.c_oflag &= ~OPOST;
ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
ktermios.c_cflag &= ~(CSIZE | PARENB);
ktermios.c_cflag |= CS8;
ktermios.c_cflag |= CRTSCTS;
/* tty_set_termios() return not checked as it is always 0 */
tty_set_termios(tty, &ktermios);
}
void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
struct tty_struct *tty = hu->tty;
struct ktermios ktermios;
ktermios = tty->termios;
ktermios.c_cflag &= ~CBAUD;
tty_termios_encode_baud_rate(&ktermios, speed, speed);
/* tty_set_termios() return not checked as it is always 0 */
tty_set_termios(tty, &ktermios);
BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
tty->termios.c_ispeed, tty->termios.c_ospeed);
}
static int hci_uart_setup(struct hci_dev *hdev)
{
struct hci_uart *hu = hci_get_drvdata(hdev);
struct hci_rp_read_local_version *ver;
struct sk_buff *skb;
unsigned int speed;
int err;
/* Init speed if any */
if (hu->proto->init_speed)
speed = hu->proto->init_speed;
else if (hu->init_speed)
speed = hu->init_speed;
else
speed = 0;
if (speed)
hci_uart_set_baudrate(hu, speed);
/* Operational speed if any */
if (hu->proto->oper_speed)
speed = hu->proto->oper_speed;
else if (hu->oper_speed)
speed = hu->oper_speed;
else
speed = 0;
if (hu->proto->set_baudrate && speed) {
err = hu->proto->set_baudrate(hu, speed);
if (!err)
hci_uart_set_baudrate(hu, speed);
}
if (hu->proto->setup)
return hu->proto->setup(hu);
if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
return 0;
skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
HCI_INIT_TIMEOUT);
if (IS_ERR(skb)) {
BT_ERR("%s: Reading local version information failed (%ld)",
hdev->name, PTR_ERR(skb));
return 0;
}
if (skb->len != sizeof(*ver)) {
BT_ERR("%s: Event length mismatch for version information",
hdev->name);
goto done;
}
ver = (struct hci_rp_read_local_version *)skb->data;
switch (le16_to_cpu(ver->manufacturer)) {
#ifdef CONFIG_BT_HCIUART_INTEL
case 2:
hdev->set_bdaddr = btintel_set_bdaddr;
btintel_check_bdaddr(hdev);
break;
#endif
#ifdef CONFIG_BT_HCIUART_BCM
case 15:
hdev->set_bdaddr = btbcm_set_bdaddr;
btbcm_check_bdaddr(hdev);
break;
#endif
}
done:
kfree_skb(skb);
return 0;
}
/* ------ LDISC part ------ */
/* hci_uart_tty_open
*
* Called when line discipline changed to HCI_UART.
*
* Arguments:
* tty pointer to tty info structure
* Return Value:
* 0 if success, otherwise error code
*/
static int hci_uart_tty_open(struct tty_struct *tty)
{
struct hci_uart *hu;
BT_DBG("tty %p", tty);
/* Error if the tty has no write op instead of leaving an exploitable
hole */
if (tty->ops->write == NULL)
return -EOPNOTSUPP;
hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
if (!hu) {
BT_ERR("Can't allocate control structure");
return -ENFILE;
}
tty->disc_data = hu;
hu->tty = tty;
tty->receive_room = 65536;
INIT_WORK(&hu->init_ready, hci_uart_init_work);
INIT_WORK(&hu->write_work, hci_uart_write_work);
spin_lock_init(&hu->rx_lock);
/* 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;
}
/* hci_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 hci_uart_tty_close(struct tty_struct *tty)
{
struct hci_uart *hu = tty->disc_data;
struct hci_dev *hdev;
BT_DBG("tty %p", tty);
/* Detach from the tty */
tty->disc_data = NULL;
if (!hu)
return;
hdev = hu->hdev;
if (hdev)
hci_uart_close(hdev);
cancel_work_sync(&hu->write_work);
if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
if (hdev) {
if (test_bit(HCI_UART_REGISTERED, &hu->flags))
hci_unregister_dev(hdev);
hci_free_dev(hdev);
}
hu->proto->close(hu);
}
kfree(hu);
}
/* hci_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 hci_uart_tty_wakeup(struct tty_struct *tty)
{
struct hci_uart *hu = tty->disc_data;
BT_DBG("");
if (!hu)
return;
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
if (tty != hu->tty)
return;
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
hci_uart_tx_wakeup(hu);
}
/* hci_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 hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
char *flags, int count)
{
struct hci_uart *hu = tty->disc_data;
if (!hu || tty != hu->tty)
return;
if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
return;
spin_lock(&hu->rx_lock);
hu->proto->recv(hu, data, count);
if (hu->hdev)
hu->hdev->stat.byte_rx += count;
spin_unlock(&hu->rx_lock);
tty_unthrottle(tty);
}
static int hci_uart_register_dev(struct hci_uart *hu)
{
struct hci_dev *hdev;
BT_DBG("");
/* Initialize and register HCI device */
hdev = hci_alloc_dev();
if (!hdev) {
BT_ERR("Can't allocate HCI device");
return -ENOMEM;
}
hu->hdev = hdev;
hdev->bus = HCI_UART;
hci_set_drvdata(hdev, hu);
hdev->open = hci_uart_open;
hdev->close = hci_uart_close;
hdev->flush = hci_uart_flush;
hdev->send = hci_uart_send_frame;
hdev->setup = hci_uart_setup;
SET_HCIDEV_DEV(hdev, hu->tty->dev);
if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
hdev->dev_type = HCI_AMP;
else
hdev->dev_type = HCI_BREDR;
if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
return 0;
if (hci_register_dev(hdev) < 0) {
BT_ERR("Can't register HCI device");
hci_free_dev(hdev);
return -ENODEV;
}
set_bit(HCI_UART_REGISTERED, &hu->flags);
return 0;
}
static int hci_uart_set_proto(struct hci_uart *hu, int id)
{
const struct hci_uart_proto *p;
int err;
p = hci_uart_get_proto(id);
if (!p)
return -EPROTONOSUPPORT;
err = p->open(hu);
if (err)
return err;
hu->proto = p;
err = hci_uart_register_dev(hu);
if (err) {
p->close(hu);
return err;
}
return 0;
}
static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
{
unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
BIT(HCI_UART_RESET_ON_INIT) |
BIT(HCI_UART_CREATE_AMP) |
BIT(HCI_UART_INIT_PENDING) |
BIT(HCI_UART_EXT_CONFIG) |
BIT(HCI_UART_VND_DETECT);
if (flags & ~valid_flags)
return -EINVAL;
hu->hdev_flags = flags;
return 0;
}
/* hci_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 hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct hci_uart *hu = tty->disc_data;
int err = 0;
BT_DBG("");
/* Verify the status of the device */
if (!hu)
return -EBADF;
switch (cmd) {
case HCIUARTSETPROTO:
if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
err = hci_uart_set_proto(hu, arg);
if (err) {
clear_bit(HCI_UART_PROTO_SET, &hu->flags);
return err;
}
} else
return -EBUSY;
break;
case HCIUARTGETPROTO:
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
return hu->proto->id;
return -EUNATCH;
case HCIUARTGETDEVICE:
if (test_bit(HCI_UART_REGISTERED, &hu->flags))
return hu->hdev->id;
return -EUNATCH;
case HCIUARTSETFLAGS:
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
return -EBUSY;
err = hci_uart_set_flags(hu, arg);
if (err)
return err;
break;
case HCIUARTGETFLAGS:
return hu->hdev_flags;
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 hci_uart_tty_read(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr)
{
return 0;
}
static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
const unsigned char *data, size_t count)
{
return 0;
}
static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
struct file *filp, poll_table *wait)
{
return 0;
}
static int __init hci_uart_init(void)
{
static struct tty_ldisc_ops hci_uart_ldisc;
int err;
BT_INFO("HCI UART driver ver %s", VERSION);
/* Register the tty discipline */
memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
hci_uart_ldisc.magic = TTY_LDISC_MAGIC;
hci_uart_ldisc.name = "n_hci";
hci_uart_ldisc.open = hci_uart_tty_open;
hci_uart_ldisc.close = hci_uart_tty_close;
hci_uart_ldisc.read = hci_uart_tty_read;
hci_uart_ldisc.write = hci_uart_tty_write;
hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;
hci_uart_ldisc.poll = hci_uart_tty_poll;
hci_uart_ldisc.receive_buf = hci_uart_tty_receive;
hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;
hci_uart_ldisc.owner = THIS_MODULE;
err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
if (err) {
BT_ERR("HCI line discipline registration failed. (%d)", err);
return err;
}
#ifdef CONFIG_BT_HCIUART_H4
h4_init();
#endif
#ifdef CONFIG_BT_HCIUART_BCSP
bcsp_init();
#endif
#ifdef CONFIG_BT_HCIUART_LL
ll_init();
#endif
#ifdef CONFIG_BT_HCIUART_ATH3K
ath_init();
#endif
#ifdef CONFIG_BT_HCIUART_3WIRE
h5_init();
#endif
#ifdef CONFIG_BT_HCIUART_BCM
bcm_init();
#endif
return 0;
}
static void __exit hci_uart_exit(void)
{
int err;
#ifdef CONFIG_BT_HCIUART_H4
h4_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_BCSP
bcsp_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_LL
ll_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_ATH3K
ath_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_3WIRE
h5_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_BCM
bcm_deinit();
#endif
/* Release tty registration of line discipline */
err = tty_unregister_ldisc(N_HCI);
if (err)
BT_ERR("Can't unregister HCI line discipline (%d)", err);
}
module_init(hci_uart_init);
module_exit(hci_uart_exit);
MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_LDISC(N_HCI);