/*
 * USB IR Dongle driver
 *
 *      Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
 *      Copyright (C) 2002      Gary Brubaker (xavyer@ix.netcom.com)
 *
 *      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 driver allows a USB IrDA device to be used as a "dumb" serial device.
 * This can be useful if you do not have access to a full IrDA stack on the
 * other side of the connection.  If you do have an IrDA stack on both devices,
 * please use the usb-irda driver, as it contains the proper error checking and
 * other goodness of a full IrDA stack.
 *
 * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
 * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
 * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 * 2007_Jun_21  Alan Cox <alan@redhat.com>
 *      Minimal cleanups for some of the driver problens and tty layer abuse.
 *      Still needs fixing to allow multiple dongles.
 *
 * 2002_Mar_07  greg kh
 *      moved some needed structures and #define values from the
 *      net/irda/irda-usb.h file into our file, as we don't want to depend on
 *      that codebase compiling correctly :)
 *
 * 2002_Jan_14  gb
 *      Added module parameter to force specific number of XBOFs.
 *      Added ir_xbof_change().
 *      Reorganized read_bulk_callback error handling.
 *      Switched from FILL_BULK_URB() to usb_fill_bulk_urb().
 *
 * 2001_Nov_08  greg kh
 *      Changed the irda_usb_find_class_desc() function based on comments and
 *      code from Martin Diehl.
 *
 * 2001_Nov_01  greg kh
 *      Added support for more IrDA USB devices.
 *      Added support for zero packet.  Added buffer override paramater, so
 *      users can transfer larger packets at once if they wish.  Both patches
 *      came from Dag Brattli <dag@obexcode.com>.
 *
 * 2001_Oct_07  greg kh
 *      initial version released.
 */

#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 <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.4"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
#define DRIVER_DESC "USB IR Dongle driver"

/* USB IrDA class spec information */
#define USB_CLASS_IRDA          0x02
#define USB_DT_IRDA             0x21
#define IU_REQ_GET_CLASS_DESC   0x06
#define SPEED_2400              0x01
#define SPEED_9600              0x02
#define SPEED_19200             0x03
#define SPEED_38400             0x04
#define SPEED_57600             0x05
#define SPEED_115200            0x06
#define SPEED_576000            0x07
#define SPEED_1152000           0x08
#define SPEED_4000000           0x09

struct irda_class_desc {
        u8      bLength;
        u8      bDescriptorType;
        u16     bcdSpecRevision;
        u8      bmDataSize;
        u8      bmWindowSize;
        u8      bmMinTurnaroundTime;
        u16     wBaudRate;
        u8      bmAdditionalBOFs;
        u8      bIrdaRateSniff;
        u8      bMaxUnicastList;
} __attribute__ ((packed));

static int debug;

/* if overridden by the user, then use their value for the size of the read and
 * write urbs */
static int buffer_size;
/* if overridden by the user, then use the specified number of XBOFs */
static int xbof = -1;

static int  ir_startup (struct usb_serial *serial);
static int  ir_open (struct usb_serial_port *port, struct file *filep);
static void ir_close (struct usb_serial_port *port, struct file *filep);
static int  ir_write (struct usb_serial_port *port, const unsigned char *buf, int count);
static void ir_write_bulk_callback (struct urb *urb);
static void ir_read_bulk_callback (struct urb *urb);
static void ir_set_termios (struct usb_serial_port *port, struct ktermios *old_termios);

/* Not that this lot means you can only have one per system */
static u8 ir_baud = 0;
static u8 ir_xbof = 0;
static u8 ir_add_bof = 0;

static struct usb_device_id id_table [] = {
        { USB_DEVICE(0x050f, 0x0180) },         /* KC Technology, KC-180 */
        { USB_DEVICE(0x08e9, 0x0100) },         /* XTNDAccess */
        { USB_DEVICE(0x09c4, 0x0011) },         /* ACTiSys ACT-IR2000U */
        { USB_INTERFACE_INFO (USB_CLASS_APP_SPEC, USB_CLASS_IRDA, 0) },
        { }                                     /* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table);

static struct usb_driver ir_driver = {
        .name =         "ir-usb",
        .probe =        usb_serial_probe,
        .disconnect =   usb_serial_disconnect,
        .id_table =     id_table,
        .no_dynamic_id =        1,
};


static struct usb_serial_driver ir_device = {
        .driver = {
                .owner =        THIS_MODULE,
                .name =         "ir-usb",
        },
        .description =          "IR Dongle",
        .usb_driver =           &ir_driver,
        .id_table =             id_table,
        .num_interrupt_in =     1,
        .num_bulk_in =          1,
        .num_bulk_out =         1,
        .num_ports =            1,
        .set_termios =          ir_set_termios,
        .attach =               ir_startup,
        .open =                 ir_open,
        .close =                ir_close,
        .write =                ir_write,
        .write_bulk_callback =  ir_write_bulk_callback,
        .read_bulk_callback =   ir_read_bulk_callback,
};

static inline void irda_usb_dump_class_desc(struct irda_class_desc *desc)
{
        dbg("bLength=%x", desc->bLength);
        dbg("bDescriptorType=%x", desc->bDescriptorType);
        dbg("bcdSpecRevision=%x", desc->bcdSpecRevision); 
        dbg("bmDataSize=%x", desc->bmDataSize);
        dbg("bmWindowSize=%x", desc->bmWindowSize);
        dbg("bmMinTurnaroundTime=%d", desc->bmMinTurnaroundTime);
        dbg("wBaudRate=%x", desc->wBaudRate);
        dbg("bmAdditionalBOFs=%x", desc->bmAdditionalBOFs);
        dbg("bIrdaRateSniff=%x", desc->bIrdaRateSniff);
        dbg("bMaxUnicastList=%x", desc->bMaxUnicastList);
}

/*------------------------------------------------------------------*/
/*
 * Function irda_usb_find_class_desc(dev, ifnum)
 *
 *    Returns instance of IrDA class descriptor, or NULL if not found
 *
 * The class descriptor is some extra info that IrDA USB devices will
 * offer to us, describing their IrDA characteristics. We will use that in
 * irda_usb_init_qos()
 *
 * Based on the same function in drivers/net/irda/irda-usb.c
 */
static struct irda_class_desc *irda_usb_find_class_desc(struct usb_device *dev, unsigned int ifnum)
{
        struct irda_class_desc *desc;
        int ret;
                
        desc = kzalloc(sizeof (struct irda_class_desc), GFP_KERNEL);
        if (desc == NULL) 
                return NULL;
        
        ret = usb_control_msg(dev, usb_rcvctrlpipe(dev,0),
                        IU_REQ_GET_CLASS_DESC,
                        USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
                        0, ifnum, desc, sizeof(*desc), 1000);
        
        dbg("%s -  ret=%d", __FUNCTION__, ret);
        if (ret < sizeof(*desc)) {
                dbg("%s - class descriptor read %s (%d)",
                                __FUNCTION__, 
                                (ret<0) ? "failed" : "too short",
                                ret);
                goto error;
        }
        if (desc->bDescriptorType != USB_DT_IRDA) {
                dbg("%s - bad class descriptor type", __FUNCTION__);
                goto error;
        }
        
        irda_usb_dump_class_desc(desc);
        return desc;
error:
        kfree(desc);
        return NULL;
}


static u8 ir_xbof_change(u8 xbof)
{
        u8 result;
        /* reference irda-usb.c */
        switch(xbof) {
                case 48: result = 0x10; break;
                case 28:
                case 24: result = 0x20; break;
                default:
                case 12: result = 0x30; break;
                case  5:
                case  6: result = 0x40; break;
                case  3: result = 0x50; break;
                case  2: result = 0x60; break;
                case  1: result = 0x70; break;
                case  0: result = 0x80; break;
        }
        return(result);
}


static int ir_startup (struct usb_serial *serial)
{
        struct irda_class_desc *irda_desc;

        irda_desc = irda_usb_find_class_desc (serial->dev, 0);
        if (irda_desc == NULL) {
                dev_err (&serial->dev->dev, "IRDA class descriptor not found, device not bound\n");
                return -ENODEV;
        }

        dbg ("%s - Baud rates supported:%s%s%s%s%s%s%s%s%s",
                __FUNCTION__,
                (irda_desc->wBaudRate & 0x0001) ? " 2400"    : "",
                (irda_desc->wBaudRate & 0x0002) ? " 9600"    : "",
                (irda_desc->wBaudRate & 0x0004) ? " 19200"   : "",
                (irda_desc->wBaudRate & 0x0008) ? " 38400"   : "",
                (irda_desc->wBaudRate & 0x0010) ? " 57600"   : "",
                (irda_desc->wBaudRate & 0x0020) ? " 115200"  : "",
                (irda_desc->wBaudRate & 0x0040) ? " 576000"  : "",
                (irda_desc->wBaudRate & 0x0080) ? " 1152000" : "",
                (irda_desc->wBaudRate & 0x0100) ? " 4000000" : "");

        switch( irda_desc->bmAdditionalBOFs ) {
                case 0x01: ir_add_bof = 48; break;
                case 0x02: ir_add_bof = 24; break;
                case 0x04: ir_add_bof = 12; break;
                case 0x08: ir_add_bof =  6; break;
                case 0x10: ir_add_bof =  3; break;
                case 0x20: ir_add_bof =  2; break;
                case 0x40: ir_add_bof =  1; break;
                case 0x80: ir_add_bof =  0; break;
                default:;
        }

        kfree (irda_desc);

        return 0;               
}

static int ir_open (struct usb_serial_port *port, struct file *filp)
{
        char *buffer;
        int result = 0;

        dbg("%s - port %d", __FUNCTION__, port->number);

        if (buffer_size) {
                /* override the default buffer sizes */
                buffer = kmalloc (buffer_size, GFP_KERNEL);
                if (!buffer) {
                        dev_err (&port->dev, "%s - out of memory.\n", __FUNCTION__);
                        return -ENOMEM;
                }
                kfree (port->read_urb->transfer_buffer);
                port->read_urb->transfer_buffer = buffer;
                port->read_urb->transfer_buffer_length = buffer_size;

                buffer = kmalloc (buffer_size, GFP_KERNEL);
                if (!buffer) {
                        dev_err (&port->dev, "%s - out of memory.\n", __FUNCTION__);
                        return -ENOMEM;
                }
                kfree (port->write_urb->transfer_buffer);
                port->write_urb->transfer_buffer = buffer;
                port->write_urb->transfer_buffer_length = buffer_size;
                port->bulk_out_size = buffer_size;
        }

        /* Start reading from the device */
        usb_fill_bulk_urb (
                port->read_urb,
                port->serial->dev, 
                usb_rcvbulkpipe(port->serial->dev, port->bulk_in_endpointAddress),
                port->read_urb->transfer_buffer,
                port->read_urb->transfer_buffer_length,
                ir_read_bulk_callback,
                port);
        result = usb_submit_urb(port->read_urb, GFP_KERNEL);
        if (result)
                dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);

        return result;
}

static void ir_close (struct usb_serial_port *port, struct file * filp)
{
        dbg("%s - port %d", __FUNCTION__, port->number);
                         
        /* shutdown our bulk read */
        usb_kill_urb(port->read_urb);
}

static int ir_write (struct usb_serial_port *port, const unsigned char *buf, int count)
{
        unsigned char *transfer_buffer;
        int result;
        int transfer_size;

        dbg("%s - port = %d, count = %d", __FUNCTION__, port->number, count);

        if (!port->tty) {
                dev_err (&port->dev, "%s - no tty???\n", __FUNCTION__);
                return 0;
        }

        if (count == 0)
                return 0;

        spin_lock_bh(&port->lock);
        if (port->write_urb_busy) {
                spin_unlock_bh(&port->lock);
                dbg("%s - already writing", __FUNCTION__);
                return 0;
        }
        port->write_urb_busy = 1;
        spin_unlock_bh(&port->lock);

        transfer_buffer = port->write_urb->transfer_buffer;
        transfer_size = min(count, port->bulk_out_size - 1);

        /*
         * The first byte of the packet we send to the device contains an
         * inband header which indicates an additional number of BOFs and
         * a baud rate change.
         *
         * See section 5.4.2.2 of the USB IrDA spec.
         */
        *transfer_buffer = ir_xbof | ir_baud;
        ++transfer_buffer;

        memcpy (transfer_buffer, buf, transfer_size);

        usb_fill_bulk_urb (
                port->write_urb,
                port->serial->dev,
                usb_sndbulkpipe(port->serial->dev,
                        port->bulk_out_endpointAddress),
                port->write_urb->transfer_buffer,
                transfer_size + 1,
                ir_write_bulk_callback,
                port);

        port->write_urb->transfer_flags = URB_ZERO_PACKET;

        result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
        if (result) {
                port->write_urb_busy = 0;
                dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
        } else
                result = transfer_size;

        return result;
}

static void ir_write_bulk_callback (struct urb *urb)
{
        struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
        int status = urb->status;

        dbg("%s - port %d", __FUNCTION__, port->number);

        port->write_urb_busy = 0;
        if (status) {
                dbg("%s - nonzero write bulk status received: %d",
                    __FUNCTION__, status);
                return;
        }

        usb_serial_debug_data (
                debug,
                &port->dev,
                __FUNCTION__,
                urb->actual_length,
                urb->transfer_buffer);

        usb_serial_port_softint(port);
}

static void ir_read_bulk_callback (struct urb *urb)
{
        struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
        struct tty_struct *tty;
        unsigned char *data = urb->transfer_buffer;
        int result;
        int status = urb->status;

        dbg("%s - port %d", __FUNCTION__, port->number);

        if (!port->open_count) {
                dbg("%s - port closed.", __FUNCTION__);
                return;
        }

        switch (status) {
                case 0: /* Successful */

                        /*
                         * The first byte of the packet we get from the device
                         * contains a busy indicator and baud rate change.
                         * See section 5.4.1.2 of the USB IrDA spec.
                         */
                        if ((*data & 0x0f) > 0)
                                ir_baud = *data & 0x0f;

                        usb_serial_debug_data (
                                debug,
                                &port->dev,
                                __FUNCTION__,
                                urb->actual_length,
                                data);

                        tty = port->tty;

                        if (tty_buffer_request_room(tty, urb->actual_length - 1)) {
                                tty_insert_flip_string(tty, data+1, urb->actual_length - 1);
                                tty_flip_buffer_push(tty);
                        }

                        /*
                         * No break here.
                         * We want to resubmit the urb so we can read
                         * again.
                         */

                case -EPROTO: /* taking inspiration from pl2303.c */

                        /* Continue trying to always read */
                        usb_fill_bulk_urb (
                                port->read_urb,
                                port->serial->dev, 
                                usb_rcvbulkpipe(port->serial->dev,
                                        port->bulk_in_endpointAddress),
                                port->read_urb->transfer_buffer,
                                port->read_urb->transfer_buffer_length,
                                ir_read_bulk_callback,
                                port);

                        result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
                        if (result)
                                dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n",
                                        __FUNCTION__, result);

                        break ;

                default:
                        dbg("%s - nonzero read bulk status received: %d",
                                __FUNCTION__, 
                                status);
                        break ;

        }

        return;
}

static void ir_set_termios (struct usb_serial_port *port, struct ktermios *old_termios)
{
        unsigned char *transfer_buffer;
        int result;
        speed_t baud;
        int ir_baud;

        dbg("%s - port %d", __FUNCTION__, port->number);

        baud = tty_get_baud_rate(port->tty);

        /*
         * FIXME, we should compare the baud request against the
         * capability stated in the IR header that we got in the
         * startup function.
         */

        switch (baud) {
                case 2400:      ir_baud = SPEED_2400; break;
                case 9600:      ir_baud = SPEED_9600; break;
                case 19200:     ir_baud = SPEED_19200; break;
                case 38400:     ir_baud = SPEED_38400; break;
                case 57600:     ir_baud = SPEED_57600; break;
                case 115200:    ir_baud = SPEED_115200; break;
                case 576000:    ir_baud = SPEED_576000; break;
                case 1152000:   ir_baud = SPEED_1152000; break;
                case 4000000:   ir_baud = SPEED_4000000; break;
                        break;
                default:
                        ir_baud = SPEED_9600;
                        baud = 9600;
        }

        if (xbof == -1)
                ir_xbof = ir_xbof_change(ir_add_bof);
        else
                ir_xbof = ir_xbof_change(xbof) ;

        /* FIXME need to check to see if our write urb is busy right
         * now, or use a urb pool.
         *
         * send the baud change out on an "empty" data packet
         */
        transfer_buffer = port->write_urb->transfer_buffer;
        *transfer_buffer = ir_xbof | ir_baud;

        usb_fill_bulk_urb (
                port->write_urb,
                port->serial->dev,
                usb_sndbulkpipe(port->serial->dev, port->bulk_out_endpointAddress),
                port->write_urb->transfer_buffer,
                1,
                ir_write_bulk_callback,
                port);

        port->write_urb->transfer_flags = URB_ZERO_PACKET;

        result = usb_submit_urb (port->write_urb, GFP_KERNEL);
        if (result)
                dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);

        /* Only speed changes are supported */
        tty_termios_copy_hw(port->tty->termios, old_termios);
        tty_encode_baud_rate(port->tty, baud, baud);
}


static int __init ir_init (void)
{
        int retval;
        retval = usb_serial_register(&ir_device);
        if (retval)
                goto failed_usb_serial_register;
        retval = usb_register(&ir_driver);
        if (retval) 
                goto failed_usb_register;
        info(DRIVER_DESC " " DRIVER_VERSION);
        return 0;
failed_usb_register:
        usb_serial_deregister(&ir_device);
failed_usb_serial_register:
        return retval;
}


static void __exit ir_exit (void)
{
        usb_deregister (&ir_driver);
        usb_serial_deregister (&ir_device);
}


module_init(ir_init);
module_exit(ir_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(xbof, int, 0);
MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
module_param(buffer_size, int, 0);
MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");