/*
 * bluetooth.c   Version 0.12
 *
 * Copyright (C) 2000, 2001 Greg Kroah-Hartman  <greg@kroah.com>
 * Copyright (C) 2000 Mark Douglas Corner       <mcorner@umich.edu>
 *
 * USB Bluetooth TTY driver, based on the Bluetooth Spec version 1.0B
 * 
 * (2001/11/30) Version 0.13 gkh
 *      - added locking patch from Masoodur Rahman <rmasoodu@in.ibm.com>
 *      - removed active variable, as open_count will do.
 *
 * (2001/07/09) Version 0.12 gkh
 *      - removed in_interrupt() call, as it doesn't make sense to do 
 *        that anymore.
 *
 * (2001/06/05) Version 0.11 gkh
 *      - Fixed problem with read urb status saying that we have shutdown,
 *        and that we shouldn't resubmit the urb.  Patch from unknown.
 *
 * (2001/05/28) Version 0.10 gkh
 *      - Fixed problem with using data from userspace in the bluetooth_write
 *        function as found by the CHECKER project.
 *      - Added a buffer to the write_urb_pool which reduces the number of
 *        buffers being created and destroyed for ever write.  Also cleans
 *        up the logic a bit.
 *      - Added a buffer to the control_urb_pool which fixes a memory leak
 *        when the device is removed from the system.
 *
 * (2001/05/28) Version 0.9 gkh
 *      Fixed problem with bluetooth==NULL for bluetooth_read_bulk_callback
 *      which was found by both the CHECKER project and Mikko Rahkonen.
 *
 * (08/04/2001) gb
 *      Identify version on module load.
 *
 * (2001/03/10) Version 0.8 gkh
 *      Fixed problem with not unlinking interrupt urb on device close
 *      and resubmitting the read urb on error with bluetooth struct.
 *      Thanks to Narayan Mohanram <narayan@RovingNetworks.com> for the
 *      fixes.
 *
 * (11/29/2000) Version 0.7 gkh
 *      Fixed problem with overrunning the tty flip buffer.
 *      Removed unneeded NULL pointer initialization.
 *
 * (10/05/2000) Version 0.6 gkh
 *      Fixed bug with urb->dev not being set properly, now that the usb
 *      core needs it.
 *      Got a real major id number and name.
 *
 * (08/06/2000) Version 0.5 gkh
 *      Fixed problem of not resubmitting the bulk read urb if there is
 *      an error in the callback.  Ericsson devices seem to need this.
 *
 * (07/11/2000) Version 0.4 gkh
 *      Fixed bug in disconnect for when we call tty_hangup
 *      Fixed bug in bluetooth_ctrl_msg where the bluetooth struct was not
 *      getting attached to the control urb properly.
 *      Fixed bug in bluetooth_write where we pay attention to the result
 *      of bluetooth_ctrl_msg.
 *
 * (08/03/2000) Version 0.3 gkh mdc
 *      Merged in Mark's changes to make the driver play nice with the Axis
 *      stack.
 *      Made the write bulk use an urb pool to enable larger transfers with
 *      fewer calls to the driver.
 *      Fixed off by one bug in acl pkt receive
 *      Made packet counters specific to each bluetooth device 
 *      Added checks for zero length callbacks
 *      Added buffers for int and bulk packets.  Had to do this otherwise 
 *      packet types could intermingle.
 *      Made a control urb pool for the control messages.
 *
 * (07/11/2000) Version 0.2 gkh
 *      Fixed a small bug found by Nils Faerber in the usb_bluetooth_probe 
 *      function.
 *
 * (07/09/2000) Version 0.1 gkh
 *      Initial release. Has support for sending ACL data (which is really just
 *      a HCI frame.) Raw HCI commands and HCI events are not supported.
 *      A ioctl will probably be needed for the HCI commands and events in the
 *      future. All isoch endpoints are ignored at this time also.
 *      This driver should work for all currently shipping USB Bluetooth 
 *      devices at this time :)
 * 
 */

/*
 * 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/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <asm/uaccess.h>

#define DEBUG
#include <linux/usb.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.13"
#define DRIVER_AUTHOR "Greg Kroah-Hartman, Mark Douglas Corner"
#define DRIVER_DESC "USB Bluetooth tty driver"

/* define this if you have hardware that is not good */
/*#define       BTBUGGYHARDWARE */

/* Class, SubClass, and Protocol codes that describe a Bluetooth device */
#define WIRELESS_CLASS_CODE                     0xe0
#define RF_SUBCLASS_CODE                        0x01
#define BLUETOOTH_PROGRAMMING_PROTOCOL_CODE     0x01


#define BLUETOOTH_TTY_MAJOR     216     /* real device node major id */
#define BLUETOOTH_TTY_MINORS    256     /* whole lotta bluetooth devices */

#define USB_BLUETOOTH_MAGIC     0x6d02  /* magic number for bluetooth struct */

#define BLUETOOTH_CONTROL_REQUEST_TYPE  0x20

/* Bluetooth packet types */
#define CMD_PKT                 0x01
#define ACL_PKT                 0x02
#define SCO_PKT                 0x03
#define EVENT_PKT               0x04
#define ERROR_PKT               0x05
#define NEG_PKT                 0x06

/* Message sizes */
#define MAX_EVENT_SIZE          0xFF
#define EVENT_HDR_SIZE          3       /* 2 for the header + 1 for the type indicator */
#define EVENT_BUFFER_SIZE       (MAX_EVENT_SIZE + EVENT_HDR_SIZE)

#define MAX_ACL_SIZE            0xFFFF
#define ACL_HDR_SIZE            5       /* 4 for the header + 1 for the type indicator */
#define ACL_BUFFER_SIZE         (MAX_ACL_SIZE + ACL_HDR_SIZE)

/* parity check flag */
#define RELEVANT_IFLAG(iflag)   (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

#define CHAR2INT16(c1,c0)       (((u32)((c1) & 0xff) << 8) + (u32)((c0) & 0xff))

#define NUM_BULK_URBS           24
#define NUM_CONTROL_URBS        16

struct usb_bluetooth {
        int                     magic;
        struct usb_device *     dev;
        struct tty_driver *     tty_driver;     /* the tty_driver for this device */
        struct tty_struct *     tty;            /* the coresponding tty for this port */

        unsigned char           minor;          /* the starting minor number for this device */
        int                     throttle;       /* throttled by tty layer */
        int                     open_count;
        
        __u8                    control_out_bInterfaceNum;
        struct urb *            control_urb_pool[NUM_CONTROL_URBS];
        struct usb_ctrlrequest  dr[NUM_CONTROL_URBS];

        unsigned char *         interrupt_in_buffer;
        struct urb *            interrupt_in_urb;
        __u8                    interrupt_in_endpointAddress;
        __u8                    interrupt_in_interval;
        int                     interrupt_in_buffer_size;

        unsigned char *         bulk_in_buffer;
        struct urb *            read_urb;
        __u8                    bulk_in_endpointAddress;
        int                     bulk_in_buffer_size;

        int                     bulk_out_buffer_size;
        struct urb *            write_urb_pool[NUM_BULK_URBS];
        __u8                    bulk_out_endpointAddress;

        wait_queue_head_t       write_wait;

        struct tq_struct        tqueue;         /* task queue for line discipline waking up */
        
        unsigned int            int_packet_pos;
        unsigned char           int_buffer[EVENT_BUFFER_SIZE];
        unsigned int            bulk_packet_pos;
        unsigned char           bulk_buffer[ACL_BUFFER_SIZE];   /* 64k preallocated, fix? */
        struct semaphore        lock;
};


/* local function prototypes */
static int  bluetooth_open              (struct tty_struct *tty, struct file *filp);
static void bluetooth_close             (struct tty_struct *tty, struct file *filp);
static int  bluetooth_write             (struct tty_struct *tty, int from_user, const unsigned char *buf, int count);
static int  bluetooth_write_room        (struct tty_struct *tty);
static int  bluetooth_chars_in_buffer   (struct tty_struct *tty);
static void bluetooth_throttle          (struct tty_struct *tty);
static void bluetooth_unthrottle        (struct tty_struct *tty);
static int  bluetooth_ioctl             (struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg);
static void bluetooth_set_termios       (struct tty_struct *tty, struct termios *old);

static void bluetooth_int_callback              (struct urb *urb);
static void bluetooth_ctrl_callback             (struct urb *urb);
static void bluetooth_read_bulk_callback        (struct urb *urb);
static void bluetooth_write_bulk_callback       (struct urb *urb);

static void * usb_bluetooth_probe(struct usb_device *dev, unsigned int ifnum,
                                  const struct usb_device_id *id);
static void usb_bluetooth_disconnect    (struct usb_device *dev, void *ptr);


static struct usb_device_id usb_bluetooth_ids [] = {
        { USB_DEVICE_INFO(WIRELESS_CLASS_CODE, RF_SUBCLASS_CODE, BLUETOOTH_PROGRAMMING_PROTOCOL_CODE) },
        { }                                             /* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, usb_bluetooth_ids);

static struct usb_driver usb_bluetooth_driver = {
        .name =         "bluetty",
        .probe =        usb_bluetooth_probe,
        .disconnect =   usb_bluetooth_disconnect,
        .id_table =     usb_bluetooth_ids,
};

static int                      bluetooth_refcount;
static struct tty_driver        bluetooth_tty_driver;
static struct tty_struct *      bluetooth_tty[BLUETOOTH_TTY_MINORS];
static struct termios *         bluetooth_termios[BLUETOOTH_TTY_MINORS];
static struct termios *         bluetooth_termios_locked[BLUETOOTH_TTY_MINORS];
static struct usb_bluetooth     *bluetooth_table[BLUETOOTH_TTY_MINORS];


static inline int bluetooth_paranoia_check (struct usb_bluetooth *bluetooth, const char *function)
{
        if (!bluetooth) {
                dbg("%s - bluetooth == NULL", function);
                return -1;
        }
        if (bluetooth->magic != USB_BLUETOOTH_MAGIC) {
                dbg("%s - bad magic number for bluetooth", function);
                return -1;
        }

        return 0;
}


static inline struct usb_bluetooth* get_usb_bluetooth (struct usb_bluetooth *bluetooth, const char *function)
{
        if (!bluetooth || 
            bluetooth_paranoia_check (bluetooth, function)) { 
                /* then say that we dont have a valid usb_bluetooth thing, which will
                 * end up generating -ENODEV return values */
                return NULL;
        }

        return bluetooth;
}


static inline struct usb_bluetooth *get_bluetooth_by_minor (int minor)
{
        return bluetooth_table[minor];
}


static int bluetooth_ctrl_msg (struct usb_bluetooth *bluetooth, int request, int value, const unsigned char *buf, int len)
{
        struct urb *urb = NULL;
        struct usb_ctrlrequest *dr = NULL;
        int i;
        int status;

        dbg ("%s", __FUNCTION__);

        /* try to find a free urb in our list */
        for (i = 0; i < NUM_CONTROL_URBS; ++i) {
                if (bluetooth->control_urb_pool[i]->status != -EINPROGRESS) {
                        urb = bluetooth->control_urb_pool[i];
                        dr = &bluetooth->dr[i];
                        break;
                }
        }
        if (urb == NULL) {
                dbg ("%s - no free urbs", __FUNCTION__);
                return -ENOMEM;
        }

        /* keep increasing the urb transfer buffer to fit the size of the message */
        if (urb->transfer_buffer == NULL) {
                urb->transfer_buffer = kmalloc (len, GFP_KERNEL);
                if (urb->transfer_buffer == NULL) {
                        err ("%s - out of memory", __FUNCTION__);
                        return -ENOMEM;
                }
        }
        if (urb->transfer_buffer_length < len) {
                kfree (urb->transfer_buffer);
                urb->transfer_buffer = kmalloc (len, GFP_KERNEL);
                if (urb->transfer_buffer == NULL) {
                        err ("%s - out of memory", __FUNCTION__);
                        return -ENOMEM;
                }
        }
        memcpy (urb->transfer_buffer, buf, len);

        dr->bRequestType= BLUETOOTH_CONTROL_REQUEST_TYPE;
        dr->bRequest = request;
        dr->wValue = cpu_to_le16((u16) value);
        dr->wIndex = cpu_to_le16((u16) bluetooth->control_out_bInterfaceNum);
        dr->wLength = cpu_to_le16((u16) len);
        
        FILL_CONTROL_URB (urb, bluetooth->dev, usb_sndctrlpipe(bluetooth->dev, 0),
                          (unsigned char*)dr, urb->transfer_buffer, len, bluetooth_ctrl_callback, bluetooth);

        /* send it down the pipe */
        status = usb_submit_urb(urb);
        if (status)
                dbg("%s - usb_submit_urb(control) failed with status = %d", __FUNCTION__, status);
        
        return status;
}





/*****************************************************************************
 * Driver tty interface functions
 *****************************************************************************/
static int bluetooth_open (struct tty_struct *tty, struct file * filp)
{
        struct usb_bluetooth *bluetooth;
        int result;

        dbg("%s", __FUNCTION__);

        /* initialize the pointer incase something fails */
        tty->driver_data = NULL;

        /* get the bluetooth object associated with this tty pointer */
        bluetooth = get_bluetooth_by_minor (MINOR(tty->device));

        if (bluetooth_paranoia_check (bluetooth, __FUNCTION__)) {
                return -ENODEV;
        }

        down (&bluetooth->lock);
 
        ++bluetooth->open_count;
        if (bluetooth->open_count == 1) {
                /* set up our structure making the tty driver remember our object, and us it */
                tty->driver_data = bluetooth;
                bluetooth->tty = tty;

                /* force low_latency on so that our tty_push actually forces the data through, 
                 * otherwise it is scheduled, and with high data rates (like with OHCI) data
                 * can get lost. */
                bluetooth->tty->low_latency = 1;
        
                /* Reset the packet position counters */
                bluetooth->int_packet_pos = 0;
                bluetooth->bulk_packet_pos = 0;

#ifndef BTBUGGYHARDWARE
                /* Start reading from the device */
                FILL_BULK_URB (bluetooth->read_urb, bluetooth->dev, 
                               usb_rcvbulkpipe(bluetooth->dev, bluetooth->bulk_in_endpointAddress),
                               bluetooth->bulk_in_buffer,
                               bluetooth->bulk_in_buffer_size,
                               bluetooth_read_bulk_callback, bluetooth);
                result = usb_submit_urb(bluetooth->read_urb);
                if (result)
                        dbg("%s - usb_submit_urb(read bulk) failed with status %d", __FUNCTION__, result);
#endif
                FILL_INT_URB (bluetooth->interrupt_in_urb, bluetooth->dev, 
                              usb_rcvintpipe(bluetooth->dev, bluetooth->interrupt_in_endpointAddress),
                              bluetooth->interrupt_in_buffer,
                              bluetooth->interrupt_in_buffer_size,
                              bluetooth_int_callback, bluetooth,
                              bluetooth->interrupt_in_interval);
                result = usb_submit_urb(bluetooth->interrupt_in_urb);
                if (result)
                        dbg("%s - usb_submit_urb(interrupt in) failed with status %d", __FUNCTION__, result);
        }
        
        up(&bluetooth->lock);

        return 0;
}


static void bluetooth_close (struct tty_struct *tty, struct file * filp)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);
        int i;

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not opened", __FUNCTION__);
                return;
        }

        down (&bluetooth->lock);
 
        --bluetooth->open_count;
        if (bluetooth->open_count <= 0) {
                bluetooth->open_count = 0;

                /* shutdown any bulk reads and writes that might be going on */
                for (i = 0; i < NUM_BULK_URBS; ++i)
                        usb_unlink_urb (bluetooth->write_urb_pool[i]);
                usb_unlink_urb (bluetooth->read_urb);
                usb_unlink_urb (bluetooth->interrupt_in_urb);
        }
        up(&bluetooth->lock);
}


static int bluetooth_write (struct tty_struct * tty, int from_user, const unsigned char *buf, int count)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);
        struct urb *urb = NULL;
        unsigned char *temp_buffer = NULL;
        const unsigned char *current_buffer;
        const unsigned char *current_position;
        int bytes_sent;
        int buffer_size;
        int i;
        int retval = 0;

        if (!bluetooth) {
                return -ENODEV;
        }

        dbg("%s - %d byte(s)", __FUNCTION__, count);

        if (!bluetooth->open_count) {
                dbg ("%s - device not opened", __FUNCTION__);
                return -EINVAL;
        }

        if (count == 0) {
                dbg("%s - write request of 0 bytes", __FUNCTION__);
                return 0;
        }
        if (count == 1) {
                dbg("%s - write request only included type %d", __FUNCTION__, buf[0]);
                return 1;
        }

#ifdef DEBUG
        printk (KERN_DEBUG __FILE__ ": %s - length = %d, data = ", __FUNCTION__, count);
        for (i = 0; i < count; ++i) {
                printk ("%.2x ", buf[i]);
        }
        printk ("\n");
#endif

        if (from_user) {
                temp_buffer = kmalloc (count, GFP_KERNEL);
                if (temp_buffer == NULL) {
                        err ("%s - out of memory.", __FUNCTION__);
                        retval = -ENOMEM;
                        goto exit;
                }
                if (copy_from_user (temp_buffer, buf, count)) {
                        retval = -EFAULT;
                        goto exit;
                }
                current_buffer = temp_buffer;
        } else {
                current_buffer = buf;
        }

        switch (*current_buffer) {
                /* First byte indicates the type of packet */
                case CMD_PKT:
                        /* dbg("%s- Send cmd_pkt len:%d", __FUNCTION__, count);*/

                        retval = bluetooth_ctrl_msg (bluetooth, 0x00, 0x00, &current_buffer[1], count-1);
                        if (retval) {
                                goto exit;
                        }
                        retval = count;
                        break;

                case ACL_PKT:
                        current_position = current_buffer;
                        ++current_position;
                        --count;
                        bytes_sent = 0;

                        while (count > 0) {
                                urb = NULL;

                                /* try to find a free urb in our list */
                                for (i = 0; i < NUM_BULK_URBS; ++i) {
                                        if (bluetooth->write_urb_pool[i]->status != -EINPROGRESS) {
                                                urb = bluetooth->write_urb_pool[i];
                                                break;
                                        }
                                }
                                if (urb == NULL) {
                                        dbg ("%s - no free urbs", __FUNCTION__);
                                        retval = bytes_sent;
                                        goto exit;
                                }
                                

                                buffer_size = min (count, bluetooth->bulk_out_buffer_size);
                                memcpy (urb->transfer_buffer, current_position, buffer_size);

                                /* build up our urb */
                                FILL_BULK_URB (urb, bluetooth->dev, usb_sndbulkpipe(bluetooth->dev, bluetooth->bulk_out_endpointAddress),
                                                urb->transfer_buffer, buffer_size, bluetooth_write_bulk_callback, bluetooth);
                                urb->transfer_flags |= USB_QUEUE_BULK;

                                /* send it down the pipe */
                                retval = usb_submit_urb(urb);
                                if (retval) {
                                        dbg("%s - usb_submit_urb(write bulk) failed with error = %d", __FUNCTION__, retval);
                                        goto exit;
                                }
#ifdef BTBUGGYHARDWARE
                                /* A workaround for the stalled data bug */
                                /* May or may not be needed...*/
                                if (count != 0) {
                                        udelay(500);
                                }
#endif
                                current_position += buffer_size;
                                bytes_sent += buffer_size;
                                count -= buffer_size;
                        }

                        retval = bytes_sent + 1;
                        break;
                
                default :
                        dbg("%s - unsupported (at this time) write type", __FUNCTION__);
                        retval = -EINVAL;
                        break;
        }

exit:
        if (temp_buffer != NULL)
                kfree (temp_buffer);

        return retval;
} 


static int bluetooth_write_room (struct tty_struct *tty) 
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);
        int room = 0;
        int i;

        if (!bluetooth) {
                return -ENODEV;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return -EINVAL;
        }

        for (i = 0; i < NUM_BULK_URBS; ++i) {
                if (bluetooth->write_urb_pool[i]->status != -EINPROGRESS) {
                        room += bluetooth->bulk_out_buffer_size;
                }
        }

        dbg("%s - returns %d", __FUNCTION__, room);
        return room;
}


static int bluetooth_chars_in_buffer (struct tty_struct *tty) 
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);
        int chars = 0;
        int i;

        if (!bluetooth) {
                return -ENODEV;
        }

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return -EINVAL;
        }

        for (i = 0; i < NUM_BULK_URBS; ++i) {
                if (bluetooth->write_urb_pool[i]->status == -EINPROGRESS) {
                        chars += bluetooth->write_urb_pool[i]->transfer_buffer_length;
                }
        }

        dbg ("%s - returns %d", __FUNCTION__, chars);
        return chars;
}


static void bluetooth_throttle (struct tty_struct * tty)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return;
        }
        
        dbg("%s unsupported (at this time)", __FUNCTION__);

        return;
}


static void bluetooth_unthrottle (struct tty_struct * tty)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return;
        }

        dbg("%s unsupported (at this time)", __FUNCTION__);
}


static int bluetooth_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);

        if (!bluetooth) {
                return -ENODEV;
        }

        dbg("%s - cmd 0x%.4x", __FUNCTION__, cmd);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return -ENODEV;
        }

        /* FIXME!!! */
        return -ENOIOCTLCMD;
}


static void bluetooth_set_termios (struct tty_struct *tty, struct termios * old)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return;
        }

        /* FIXME!!! */

        return;
}


#ifdef BTBUGGYHARDWARE
void btusb_enable_bulk_read(struct tty_struct *tty){
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);
        int result;

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return;
        }

        if (bluetooth->read_urb) {
                FILL_BULK_URB(bluetooth->read_urb, bluetooth->dev, 
                              usb_rcvbulkpipe(bluetooth->dev, bluetooth->bulk_in_endpointAddress),
                              bluetooth->bulk_in_buffer, bluetooth->bulk_in_buffer_size, 
                              bluetooth_read_bulk_callback, bluetooth);
                result = usb_submit_urb(bluetooth->read_urb);
                if (result)
                        err ("%s - failed submitting read urb, error %d", __FUNCTION__, result);
        }
}

void btusb_disable_bulk_read(struct tty_struct *tty){
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)tty->driver_data, __FUNCTION__);

        if (!bluetooth) {
                return;
        }

        dbg("%s", __FUNCTION__);

        if (!bluetooth->open_count) {
                dbg ("%s - device not open", __FUNCTION__);
                return;
        }

        if ((bluetooth->read_urb) && (bluetooth->read_urb->actual_length))
                usb_unlink_urb(bluetooth->read_urb);
}
#endif


/*****************************************************************************
 * urb callback functions
 *****************************************************************************/


static void bluetooth_int_callback (struct urb *urb)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)urb->context, __FUNCTION__);
        unsigned char *data = urb->transfer_buffer;
        unsigned int i;
        unsigned int count = urb->actual_length;
        unsigned int packet_size;

        dbg("%s", __FUNCTION__);

        if (!bluetooth) {
                dbg("%s - bad bluetooth pointer, exiting", __FUNCTION__);
                return;
        }

        if (urb->status) {
                dbg("%s - nonzero int status received: %d", __FUNCTION__, urb->status);
                return;
        }

        if (!count) {
                dbg("%s - zero length int", __FUNCTION__);
                return;
        }


#ifdef DEBUG
        if (count) {
                printk (KERN_DEBUG __FILE__ ": %s- length = %d, data = ", __FUNCTION__, count);
                for (i = 0; i < count; ++i) {
                        printk ("%.2x ", data[i]);
                }
                printk ("\n");
        }
#endif

#ifdef BTBUGGYHARDWARE
        if ((count >= 2) && (data[0] == 0xFF) && (data[1] == 0x00)) {
                data += 2;
                count -= 2;
        }
        if (count == 0) {
                urb->actual_length = 0;
                return;
        }
#endif
        /* We add  a packet type identifier to the beginning of each
           HCI frame.  This makes the data in the tty look like a
           serial USB devices.  Each HCI frame can be broken across
           multiple URBs so we buffer them until we have a full hci
           packet */

        if (!bluetooth->int_packet_pos) {
                bluetooth->int_buffer[0] = EVENT_PKT;
                bluetooth->int_packet_pos++;
        }
        
        if (bluetooth->int_packet_pos + count > EVENT_BUFFER_SIZE) {
                err("%s - exceeded EVENT_BUFFER_SIZE", __FUNCTION__);
                bluetooth->int_packet_pos = 0;
                return;
        }

        memcpy (&bluetooth->int_buffer[bluetooth->int_packet_pos],
                urb->transfer_buffer, count);
        bluetooth->int_packet_pos += count;
        urb->actual_length = 0;

        if (bluetooth->int_packet_pos >= EVENT_HDR_SIZE)
                packet_size = bluetooth->int_buffer[2];
        else
                return;

        if (packet_size + EVENT_HDR_SIZE < bluetooth->int_packet_pos) {
                err("%s - packet was too long", __FUNCTION__);
                bluetooth->int_packet_pos = 0;
                return;
        }

        if (packet_size + EVENT_HDR_SIZE == bluetooth->int_packet_pos) {
                for (i = 0; i < bluetooth->int_packet_pos; ++i) {
                        /* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them */
                        if (bluetooth->tty->flip.count >= TTY_FLIPBUF_SIZE) {
                                tty_flip_buffer_push(bluetooth->tty);
                        }
                        tty_insert_flip_char(bluetooth->tty, bluetooth->int_buffer[i], 0);
                }
                tty_flip_buffer_push(bluetooth->tty);

                bluetooth->int_packet_pos = 0;
        }
}


static void bluetooth_ctrl_callback (struct urb *urb)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)urb->context, __FUNCTION__);

        dbg("%s", __FUNCTION__);

        if (!bluetooth) {
                dbg("%s - bad bluetooth pointer, exiting", __FUNCTION__);
                return;
        }

        if (urb->status) {
                dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
                return;
        }
}


static void bluetooth_read_bulk_callback (struct urb *urb)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)urb->context, __FUNCTION__);
        unsigned char *data = urb->transfer_buffer;
        unsigned int count = urb->actual_length;
        unsigned int i;
        unsigned int packet_size;
        int result;


        dbg("%s", __FUNCTION__);

        if (!bluetooth) {
                dbg("%s - bad bluetooth pointer, exiting", __FUNCTION__);
                return;
        }

        if (urb->status) {
                dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
                if (urb->status == -ENOENT) {                   
                        dbg("%s - URB canceled, won't reschedule", __FUNCTION__);
                        return;
                }
                goto exit;
        }

        if (!count) {
                dbg("%s - zero length read bulk", __FUNCTION__);
                goto exit;
        }

#ifdef DEBUG
        if (count) {
                printk (KERN_DEBUG __FILE__ ": %s- length = %d, data = ", __FUNCTION__, count);
                for (i = 0; i < count; ++i) {
                        printk ("%.2x ", data[i]);
                }
                printk ("\n");
        }
#endif
#ifdef BTBUGGYHARDWARE
        if ((count == 4) && (data[0] == 0x00) && (data[1] == 0x00)
            && (data[2] == 0x00) && (data[3] == 0x00)) {
                urb->actual_length = 0;
                FILL_BULK_URB(bluetooth->read_urb, bluetooth->dev, 
                              usb_rcvbulkpipe(bluetooth->dev, bluetooth->bulk_in_endpointAddress),
                              bluetooth->bulk_in_buffer, bluetooth->bulk_in_buffer_size, 
                              bluetooth_read_bulk_callback, bluetooth);
                result = usb_submit_urb(bluetooth->read_urb);
                if (result)
                        err ("%s - failed resubmitting read urb, error %d", __FUNCTION__, result);

                return;
        }
#endif
        /* We add  a packet type identifier to the beginning of each
           HCI frame.  This makes the data in the tty look like a
           serial USB devices.  Each HCI frame can be broken across
           multiple URBs so we buffer them until we have a full hci
           packet */
        
        if (!bluetooth->bulk_packet_pos) {
                bluetooth->bulk_buffer[0] = ACL_PKT;
                bluetooth->bulk_packet_pos++;
        }

        if (bluetooth->bulk_packet_pos + count > ACL_BUFFER_SIZE) {
                err("%s - exceeded ACL_BUFFER_SIZE", __FUNCTION__);
                bluetooth->bulk_packet_pos = 0;
                goto exit;
        }

        memcpy (&bluetooth->bulk_buffer[bluetooth->bulk_packet_pos],
                urb->transfer_buffer, count);
        bluetooth->bulk_packet_pos += count;
        urb->actual_length = 0;

        if (bluetooth->bulk_packet_pos >= ACL_HDR_SIZE) {
                packet_size = CHAR2INT16(bluetooth->bulk_buffer[4],bluetooth->bulk_buffer[3]);
        } else {
                goto exit;
        }

        if (packet_size + ACL_HDR_SIZE < bluetooth->bulk_packet_pos) {
                err("%s - packet was too long", __FUNCTION__);
                bluetooth->bulk_packet_pos = 0;
                goto exit;
        }

        if (packet_size + ACL_HDR_SIZE == bluetooth->bulk_packet_pos) {
                for (i = 0; i < bluetooth->bulk_packet_pos; ++i) {
                        /* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
                        if (bluetooth->tty->flip.count >= TTY_FLIPBUF_SIZE) {
                                tty_flip_buffer_push(bluetooth->tty);
                        }
                        tty_insert_flip_char(bluetooth->tty, bluetooth->bulk_buffer[i], 0);
                }
                tty_flip_buffer_push(bluetooth->tty);
                bluetooth->bulk_packet_pos = 0;
        }       

exit:
        if (!bluetooth || !bluetooth->open_count)
                return;

        FILL_BULK_URB(bluetooth->read_urb, bluetooth->dev, 
                      usb_rcvbulkpipe(bluetooth->dev, bluetooth->bulk_in_endpointAddress),
                      bluetooth->bulk_in_buffer, bluetooth->bulk_in_buffer_size, 
                      bluetooth_read_bulk_callback, bluetooth);
        result = usb_submit_urb(bluetooth->read_urb);
        if (result)
                err ("%s - failed resubmitting read urb, error %d", __FUNCTION__, result);

        return;
}


static void bluetooth_write_bulk_callback (struct urb *urb)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)urb->context, __FUNCTION__);

        dbg("%s", __FUNCTION__);

        if (!bluetooth) {
                dbg("%s - bad bluetooth pointer, exiting", __FUNCTION__);

                return;
        }

        if (urb->status) {
                dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
                return;
        }

        /* wake up our little function to let the tty layer know that something happened */
        queue_task(&bluetooth->tqueue, &tq_immediate);
        mark_bh(IMMEDIATE_BH);
        return;
}


static void bluetooth_softint(void *private)
{
        struct usb_bluetooth *bluetooth = get_usb_bluetooth ((struct usb_bluetooth *)private, __FUNCTION__);
        struct tty_struct *tty;

        dbg("%s", __FUNCTION__);

        if (!bluetooth) {
                return;
        }

        tty = bluetooth->tty;
        if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && tty->ldisc.write_wakeup) {
                dbg("%s - write wakeup call.", __FUNCTION__);
                (tty->ldisc.write_wakeup)(tty);
        }

        wake_up_interruptible(&tty->write_wait);
}


static void * usb_bluetooth_probe(struct usb_device *dev, unsigned int ifnum,
                                  const struct usb_device_id *id)
{
        struct usb_bluetooth *bluetooth = NULL;
        struct usb_interface_descriptor *interface;
        struct usb_endpoint_descriptor *endpoint;
        struct usb_endpoint_descriptor *interrupt_in_endpoint[8];
        struct usb_endpoint_descriptor *bulk_in_endpoint[8];
        struct usb_endpoint_descriptor *bulk_out_endpoint[8];
        int control_out_endpoint;

        int minor;
        int buffer_size;
        int i;
        int num_interrupt_in = 0;
        int num_bulk_in = 0;
        int num_bulk_out = 0;

        interface = &dev->actconfig->interface[ifnum].altsetting[0];
        control_out_endpoint = interface->bInterfaceNumber;

        /* find the endpoints that we need */
        for (i = 0; i < interface->bNumEndpoints; ++i) {
                endpoint = &interface->endpoint[i];

                if ((endpoint->bEndpointAddress & 0x80) &&
                    ((endpoint->bmAttributes & 3) == 0x02)) {
                        /* we found a bulk in endpoint */
                        dbg("found bulk in");
                        bulk_in_endpoint[num_bulk_in] = endpoint;
                        ++num_bulk_in;
                }

                if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
                    ((endpoint->bmAttributes & 3) == 0x02)) {
                        /* we found a bulk out endpoint */
                        dbg("found bulk out");
                        bulk_out_endpoint[num_bulk_out] = endpoint;
                        ++num_bulk_out;
                }

                if ((endpoint->bEndpointAddress & 0x80) &&
                    ((endpoint->bmAttributes & 3) == 0x03)) {
                        /* we found a interrupt in endpoint */
                        dbg("found interrupt in");
                        interrupt_in_endpoint[num_interrupt_in] = endpoint;
                        ++num_interrupt_in;
                }
        }

        /* according to the spec, we can only have 1 bulk_in, 1 bulk_out, and 1 interrupt_in endpoints */
        if ((num_bulk_in != 1) ||
            (num_bulk_out != 1) ||
            (num_interrupt_in != 1)) {
                dbg ("%s - improper number of endpoints. Bluetooth driver not bound.", __FUNCTION__);
                return NULL;
        }

        MOD_INC_USE_COUNT;
        info("USB Bluetooth converter detected");

        for (minor = 0; minor < BLUETOOTH_TTY_MINORS && bluetooth_table[minor]; ++minor)
                ;
        if (bluetooth_table[minor]) {
                err("No more free Bluetooth devices");
                MOD_DEC_USE_COUNT;
                return NULL;
        }

        if (!(bluetooth = kmalloc(sizeof(struct usb_bluetooth), GFP_KERNEL))) {
                err("Out of memory");
                MOD_DEC_USE_COUNT;
                return NULL;
        }

        memset(bluetooth, 0, sizeof(struct usb_bluetooth));

        bluetooth->magic = USB_BLUETOOTH_MAGIC;
        bluetooth->dev = dev;
        bluetooth->minor = minor;
        bluetooth->tqueue.routine = bluetooth_softint;
        bluetooth->tqueue.data = bluetooth;
        init_MUTEX(&bluetooth->lock);

        /* record the interface number for the control out */
        bluetooth->control_out_bInterfaceNum = control_out_endpoint;
        
        /* create our control out urb pool */ 
        for (i = 0; i < NUM_CONTROL_URBS; ++i) {
                struct urb  *urb = usb_alloc_urb(0);
                if (urb == NULL) {
                        err("No free urbs available");
                        goto probe_error;
                }
                urb->transfer_buffer = NULL;
                bluetooth->control_urb_pool[i] = urb;
        }

        /* set up the endpoint information */
        endpoint = bulk_in_endpoint[0];
        bluetooth->read_urb = usb_alloc_urb (0);
        if (!bluetooth->read_urb) {
                err("No free urbs available");
                goto probe_error;
        }
        bluetooth->bulk_in_buffer_size = buffer_size = endpoint->wMaxPacketSize;
        bluetooth->bulk_in_endpointAddress = endpoint->bEndpointAddress;
        bluetooth->bulk_in_buffer = kmalloc (buffer_size, GFP_KERNEL);
        if (!bluetooth->bulk_in_buffer) {
                err("Couldn't allocate bulk_in_buffer");
                goto probe_error;
        }
        FILL_BULK_URB(bluetooth->read_urb, dev, usb_rcvbulkpipe(dev, endpoint->bEndpointAddress),
                      bluetooth->bulk_in_buffer, buffer_size, bluetooth_read_bulk_callback, bluetooth);

        endpoint = bulk_out_endpoint[0];
        bluetooth->bulk_out_endpointAddress = endpoint->bEndpointAddress;
        bluetooth->bulk_out_buffer_size = endpoint->wMaxPacketSize * 2;

        /* create our write urb pool */ 
        for (i = 0; i < NUM_BULK_URBS; ++i) {
                struct urb  *urb = usb_alloc_urb(0);
                if (urb == NULL) {
                        err("No free urbs available");
                        goto probe_error;
                }
                urb->transfer_buffer = kmalloc (bluetooth->bulk_out_buffer_size, GFP_KERNEL);
                if (urb->transfer_buffer == NULL) {
                        err("out of memory");
                        goto probe_error;
                }
                bluetooth->write_urb_pool[i] = urb;
        }

        endpoint = interrupt_in_endpoint[0];
        bluetooth->interrupt_in_urb = usb_alloc_urb(0);
        if (!bluetooth->interrupt_in_urb) {
                err("No free urbs available");
                goto probe_error;
        }
        bluetooth->interrupt_in_buffer_size = buffer_size = endpoint->wMaxPacketSize;
        bluetooth->interrupt_in_endpointAddress = endpoint->bEndpointAddress;
        bluetooth->interrupt_in_interval = endpoint->bInterval;
        bluetooth->interrupt_in_buffer = kmalloc (buffer_size, GFP_KERNEL);
        if (!bluetooth->interrupt_in_buffer) {
                err("Couldn't allocate interrupt_in_buffer");
                goto probe_error;
        }
        FILL_INT_URB(bluetooth->interrupt_in_urb, dev, usb_rcvintpipe(dev, endpoint->bEndpointAddress),
                     bluetooth->interrupt_in_buffer, buffer_size, bluetooth_int_callback,
                     bluetooth, endpoint->bInterval);

        /* initialize the devfs nodes for this device and let the user know what bluetooths we are bound to */
        tty_register_devfs (&bluetooth_tty_driver, 0, minor);
        info("Bluetooth converter now attached to ttyUB%d (or usb/ttub/%d for devfs)", minor, minor);

        bluetooth_table[minor] = bluetooth;

        return bluetooth; /* success */

probe_error:
        if (bluetooth->read_urb)
                usb_free_urb (bluetooth->read_urb);
        if (bluetooth->bulk_in_buffer)
                kfree (bluetooth->bulk_in_buffer);
        if (bluetooth->interrupt_in_urb)
                usb_free_urb (bluetooth->interrupt_in_urb);
        if (bluetooth->interrupt_in_buffer)
                kfree (bluetooth->interrupt_in_buffer);
        for (i = 0; i < NUM_BULK_URBS; ++i)
                if (bluetooth->write_urb_pool[i]) {
                        if (bluetooth->write_urb_pool[i]->transfer_buffer)
                                kfree (bluetooth->write_urb_pool[i]->transfer_buffer);
                        usb_free_urb (bluetooth->write_urb_pool[i]);
                }
        for (i = 0; i < NUM_CONTROL_URBS; ++i) 
                if (bluetooth->control_urb_pool[i]) {
                        if (bluetooth->control_urb_pool[i]->transfer_buffer)
                                kfree (bluetooth->control_urb_pool[i]->transfer_buffer);
                        usb_free_urb (bluetooth->control_urb_pool[i]);
                }

        bluetooth_table[minor] = NULL;

        /* free up any memory that we allocated */
        kfree (bluetooth);
        MOD_DEC_USE_COUNT;
        return NULL;
}


static void usb_bluetooth_disconnect(struct usb_device *dev, void *ptr)
{
        struct usb_bluetooth *bluetooth = (struct usb_bluetooth *) ptr;
        int i;

        if (bluetooth) {
                if ((bluetooth->open_count) && (bluetooth->tty))
                        tty_hangup(bluetooth->tty);

                bluetooth->open_count = 0;

                if (bluetooth->read_urb) {
                        usb_unlink_urb (bluetooth->read_urb);
                        usb_free_urb (bluetooth->read_urb);
                }
                if (bluetooth->bulk_in_buffer)
                        kfree (bluetooth->bulk_in_buffer);

                if (bluetooth->interrupt_in_urb) {
                        usb_unlink_urb (bluetooth->interrupt_in_urb);
                        usb_free_urb (bluetooth->interrupt_in_urb);
                }
                if (bluetooth->interrupt_in_buffer)
                        kfree (bluetooth->interrupt_in_buffer);

                tty_unregister_devfs (&bluetooth_tty_driver, bluetooth->minor);

                for (i = 0; i < NUM_BULK_URBS; ++i) {
                        if (bluetooth->write_urb_pool[i]) {
                                usb_unlink_urb (bluetooth->write_urb_pool[i]);
                                if (bluetooth->write_urb_pool[i]->transfer_buffer)
                                        kfree (bluetooth->write_urb_pool[i]->transfer_buffer);
                                usb_free_urb (bluetooth->write_urb_pool[i]);
                        }
                }
                for (i = 0; i < NUM_CONTROL_URBS; ++i) {
                        if (bluetooth->control_urb_pool[i]) {
                                usb_unlink_urb (bluetooth->control_urb_pool[i]);
                                if (bluetooth->control_urb_pool[i]->transfer_buffer)
                                        kfree (bluetooth->control_urb_pool[i]->transfer_buffer);
                                usb_free_urb (bluetooth->control_urb_pool[i]);
                        }
                }
                
                info("Bluetooth converter now disconnected from ttyUB%d", bluetooth->minor);

                bluetooth_table[bluetooth->minor] = NULL;

                /* free up any memory that we allocated */
                kfree (bluetooth);

        } else {
                info("device disconnected");
        }

        MOD_DEC_USE_COUNT;
}


static struct tty_driver bluetooth_tty_driver = {
        .magic =                TTY_DRIVER_MAGIC,
        .driver_name =          "usb-bluetooth",
        .name =                 "usb/ttub/%d",
        .major =                BLUETOOTH_TTY_MAJOR,
        .minor_start =          0,
        .num =                  BLUETOOTH_TTY_MINORS,
        .type =                 TTY_DRIVER_TYPE_SERIAL,
        .subtype =              SERIAL_TYPE_NORMAL,
        .flags =                TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,

        .refcount =             &bluetooth_refcount,
        .table =                bluetooth_tty,
        .termios =              bluetooth_termios,
        .termios_locked =       bluetooth_termios_locked,

        .open =                 bluetooth_open,
        .close =                bluetooth_close,
        .write =                bluetooth_write,
        .write_room =           bluetooth_write_room,
        .ioctl =                bluetooth_ioctl,
        .set_termios =          bluetooth_set_termios,
        .throttle =             bluetooth_throttle,
        .unthrottle =           bluetooth_unthrottle,
        .chars_in_buffer =      bluetooth_chars_in_buffer,
};


int usb_bluetooth_init(void)
{
        int i;
        int result;

        /* Initalize our global data */
        for (i = 0; i < BLUETOOTH_TTY_MINORS; ++i) {
                bluetooth_table[i] = NULL;
        }

        info ("USB Bluetooth support registered");

        /* register the tty driver */
        bluetooth_tty_driver.init_termios          = tty_std_termios;
        bluetooth_tty_driver.init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
        if (tty_register_driver (&bluetooth_tty_driver)) {
                err("%s - failed to register tty driver", __FUNCTION__);
                return -1;
        }

        /* register the USB driver */
        result = usb_register(&usb_bluetooth_driver);
        if (result < 0) {
                tty_unregister_driver(&bluetooth_tty_driver);
                err("usb_register failed for the USB bluetooth driver. Error number %d", result);
                return -1;
        }

        info(DRIVER_DESC " " DRIVER_VERSION);

        return 0;
}


void usb_bluetooth_exit(void)
{
        usb_deregister(&usb_bluetooth_driver);
        tty_unregister_driver(&bluetooth_tty_driver);
}


module_init(usb_bluetooth_init);
module_exit(usb_bluetooth_exit);

/* Module information */
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");