USB: omninet: fix write_room

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / usb / serial / kl5kusb105.c

/*
 * KLSI KL5KUSB105 chip RS232 converter driver
 *
 *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
 *
 *   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.
 *
 * All information about the device was acquired using SniffUSB ans snoopUSB
 * on Windows98.
 * It was written out of frustration with the PalmConnect USB Serial adapter
 * sold by Palm Inc.
 * Neither Palm, nor their contractor (MCCI) or their supplier (KLSI) provided
 * information that was not already available.
 *
 * It seems that KLSI bought some silicon-design information from ScanLogic,
 * whose SL11R processor is at the core of the KL5KUSB chipset from KLSI.
 * KLSI has firmware available for their devices; it is probable that the
 * firmware differs from that used by KLSI in their products. If you have an
 * original KLSI device and can provide some information on it, I would be
 * most interested in adding support for it here. If you have any information
 * on the protocol used (or find errors in my reverse-engineered stuff), please
 * let me know.
 *
 * The code was only tested with a PalmConnect USB adapter; if you
 * are adventurous, try it with any KLSI-based device and let me know how it
 * breaks so that I can fix it!
 */

/* TODO:
 *      check modem line signals
 *      implement handshaking or decide that we do not support it
 */

/* History:
 *   0.3a - implemented pools of write URBs
 *   0.3  - alpha version for public testing
 *   0.2  - TIOCMGET works, so autopilot(1) can be used!
 *   0.1  - can be used to do pilot-xfer -p /dev/ttyUSB0 -l
 *
 *   The driver skeleton is mainly based on mct_u232.c and various other
 *   pieces of code shamelessly copied from the drivers/usb/serial/ directory.
 */


#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/uaccess.h>
#include <asm/unaligned.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include "kl5kusb105.h"

static int debug;

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.3a"
#define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>"
#define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"


/*
 * Function prototypes
 */
static int  klsi_105_startup(struct usb_serial *serial);
static void klsi_105_disconnect(struct usb_serial *serial);
static void klsi_105_release(struct usb_serial *serial);
static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
static void klsi_105_close(struct usb_serial_port *port);
static int  klsi_105_write(struct tty_struct *tty,
        struct usb_serial_port *port, const unsigned char *buf, int count);
static void klsi_105_write_bulk_callback(struct urb *urb);
static int  klsi_105_chars_in_buffer(struct tty_struct *tty);
static int  klsi_105_write_room(struct tty_struct *tty);
static void klsi_105_read_bulk_callback(struct urb *urb);
static void klsi_105_set_termios(struct tty_struct *tty,
                        struct usb_serial_port *port, struct ktermios *old);
static void klsi_105_throttle(struct tty_struct *tty);
static void klsi_105_unthrottle(struct tty_struct *tty);
static int  klsi_105_tiocmget(struct tty_struct *tty, struct file *file);
static int  klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
                        unsigned int set, unsigned int clear);

/*
 * All of the device info needed for the KLSI converters.
 */
static struct usb_device_id id_table [] = {
        { USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
        { USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
        { }             /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_driver kl5kusb105d_driver = {
        .name =         "kl5kusb105d",
        .probe =        usb_serial_probe,
        .disconnect =   usb_serial_disconnect,
        .id_table =     id_table,
        .no_dynamic_id =        1,
};

static struct usb_serial_driver kl5kusb105d_device = {
        .driver = {
                .owner =        THIS_MODULE,
                .name =         "kl5kusb105d",
        },
        .description =       "KL5KUSB105D / PalmConnect",
        .usb_driver =        &kl5kusb105d_driver,
        .id_table =          id_table,
        .num_ports =         1,
        .open =              klsi_105_open,
        .close =             klsi_105_close,
        .write =             klsi_105_write,
        .write_bulk_callback = klsi_105_write_bulk_callback,
        .chars_in_buffer =   klsi_105_chars_in_buffer,
        .write_room =        klsi_105_write_room,
        .read_bulk_callback = klsi_105_read_bulk_callback,
        .set_termios =       klsi_105_set_termios,
        /*.break_ctl =       klsi_105_break_ctl,*/
        .tiocmget =          klsi_105_tiocmget,
        .tiocmset =          klsi_105_tiocmset,
        .attach =            klsi_105_startup,
        .disconnect =        klsi_105_disconnect,
        .release =           klsi_105_release,
        .throttle =          klsi_105_throttle,
        .unthrottle =        klsi_105_unthrottle,
};

struct klsi_105_port_settings {
        __u8    pktlen;         /* always 5, it seems */
        __u8    baudrate;
        __u8    databits;
        __u8    unknown1;
        __u8    unknown2;
} __attribute__ ((packed));

/* we implement a pool of NUM_URBS urbs per usb_serial */
#define NUM_URBS                        1
#define URB_TRANSFER_BUFFER_SIZE        64
struct klsi_105_private {
        struct klsi_105_port_settings   cfg;
        struct ktermios                 termios;
        unsigned long                   line_state; /* modem line settings */
        /* write pool */
        struct urb                      *write_urb_pool[NUM_URBS];
        spinlock_t                      lock;
        unsigned long                   bytes_in;
        unsigned long                   bytes_out;
};


/*
 * Handle vendor specific USB requests
 */


#define KLSI_TIMEOUT     5000 /* default urb timeout */

static int klsi_105_chg_port_settings(struct usb_serial_port *port,
                                      struct klsi_105_port_settings *settings)
{
        int rc;

        rc = usb_control_msg(port->serial->dev,
                        usb_sndctrlpipe(port->serial->dev, 0),
                        KL5KUSB105A_SIO_SET_DATA,
                        USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
                        0, /* value */
                        0, /* index */
                        settings,
                        sizeof(struct klsi_105_port_settings),
                        KLSI_TIMEOUT);
        if (rc < 0)
                dev_err(&port->dev,
                        "Change port settings failed (error = %d)\n", rc);
        dev_info(&port->serial->dev->dev,
                 "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
                 settings->pktlen, settings->baudrate, settings->databits,
                 settings->unknown1, settings->unknown2);
        return rc;
} /* klsi_105_chg_port_settings */

/* translate a 16-bit status value from the device to linux's TIO bits */
static unsigned long klsi_105_status2linestate(const __u16 status)
{
        unsigned long res = 0;

        res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
              | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
              ;

        return res;
}
/*
 * Read line control via vendor command and return result through
 * *line_state_p
 */
/* It seems that the status buffer has always only 2 bytes length */
#define KLSI_STATUSBUF_LEN      2
static int klsi_105_get_line_state(struct usb_serial_port *port,
                                   unsigned long *line_state_p)
{
        int rc;
        __u8 status_buf[KLSI_STATUSBUF_LEN] = { -1, -1};
        __u16 status;

        dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
        rc = usb_control_msg(port->serial->dev,
                             usb_rcvctrlpipe(port->serial->dev, 0),
                             KL5KUSB105A_SIO_POLL,
                             USB_TYPE_VENDOR | USB_DIR_IN,
                             0, /* value */
                             0, /* index */
                             status_buf, KLSI_STATUSBUF_LEN,
                             10000
                             );
        if (rc < 0)
                dev_err(&port->dev, "Reading line status failed (error = %d)\n",
                        rc);
        else {
                status = get_unaligned_le16(status_buf);

                dev_info(&port->serial->dev->dev, "read status %x %x",
                         status_buf[0], status_buf[1]);

                *line_state_p = klsi_105_status2linestate(status);
        }
        return rc;
}


/*
 * Driver's tty interface functions
 */

static int klsi_105_startup(struct usb_serial *serial)
{
        struct klsi_105_private *priv;
        int i, j;

        /* check if we support the product id (see keyspan.c)
         * FIXME
         */

        /* allocate the private data structure */
        for (i = 0; i < serial->num_ports; i++) {
                priv = kmalloc(sizeof(struct klsi_105_private),
                                                   GFP_KERNEL);
                if (!priv) {
                        dbg("%skmalloc for klsi_105_private failed.", __func__);
                        i--;
                        goto err_cleanup;
                }
                /* set initial values for control structures */
                priv->cfg.pktlen    = 5;
                priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
                priv->cfg.databits  = kl5kusb105a_dtb_8;
                priv->cfg.unknown1  = 0;
                priv->cfg.unknown2  = 1;

                priv->line_state    = 0;

                priv->bytes_in      = 0;
                priv->bytes_out     = 0;
                usb_set_serial_port_data(serial->port[i], priv);

                spin_lock_init(&priv->lock);
                for (j = 0; j < NUM_URBS; j++) {
                        struct urb *urb = usb_alloc_urb(0, GFP_KERNEL);

                        priv->write_urb_pool[j] = urb;
                        if (urb == NULL) {
                                dev_err(&serial->dev->dev, "No more urbs???\n");
                                goto err_cleanup;
                        }

                        urb->transfer_buffer =
                                kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
                        if (!urb->transfer_buffer) {
                                dev_err(&serial->dev->dev,
                                        "%s - out of memory for urb buffers.\n",
                                        __func__);
                                goto err_cleanup;
                        }
                }

                /* priv->termios is left uninitalized until port opening */
                init_waitqueue_head(&serial->port[i]->write_wait);
        }

        return 0;

err_cleanup:
        for (; i >= 0; i--) {
                priv = usb_get_serial_port_data(serial->port[i]);
                for (j = 0; j < NUM_URBS; j++) {
                        if (priv->write_urb_pool[j]) {
                                kfree(priv->write_urb_pool[j]->transfer_buffer);
                                usb_free_urb(priv->write_urb_pool[j]);
                        }
                }
                kfree(priv);
                usb_set_serial_port_data(serial->port[i], NULL);
        }
        return -ENOMEM;
} /* klsi_105_startup */


static void klsi_105_disconnect(struct usb_serial *serial)
{
        int i;

        dbg("%s", __func__);

        /* stop reads and writes on all ports */
        for (i = 0; i < serial->num_ports; ++i) {
                struct klsi_105_private *priv =
                                usb_get_serial_port_data(serial->port[i]);

                if (priv) {
                        /* kill our write urb pool */
                        int j;
                        struct urb **write_urbs = priv->write_urb_pool;

                        for (j = 0; j < NUM_URBS; j++) {
                                if (write_urbs[j]) {
                                        usb_kill_urb(write_urbs[j]);
                                        usb_free_urb(write_urbs[j]);
                                }
                        }
                }
        }
} /* klsi_105_disconnect */


static void klsi_105_release(struct usb_serial *serial)
{
        int i;

        dbg("%s", __func__);

        for (i = 0; i < serial->num_ports; ++i) {
                struct klsi_105_private *priv =
                                usb_get_serial_port_data(serial->port[i]);

                kfree(priv);
        }
} /* klsi_105_release */

static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
{
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        int retval = 0;
        int rc;
        int i;
        unsigned long line_state;
        struct klsi_105_port_settings cfg;
        unsigned long flags;

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

        /* Do a defined restart:
         * Set up sane default baud rate and send the 'READ_ON'
         * vendor command.
         * FIXME: set modem line control (how?)
         * Then read the modem line control and store values in
         * priv->line_state.
         */
        cfg.pktlen   = 5;
        cfg.baudrate = kl5kusb105a_sio_b9600;
        cfg.databits = kl5kusb105a_dtb_8;
        cfg.unknown1 = 0;
        cfg.unknown2 = 1;
        klsi_105_chg_port_settings(port, &cfg);

        /* set up termios structure */
        spin_lock_irqsave(&priv->lock, flags);
        priv->termios.c_iflag = tty->termios->c_iflag;
        priv->termios.c_oflag = tty->termios->c_oflag;
        priv->termios.c_cflag = tty->termios->c_cflag;
        priv->termios.c_lflag = tty->termios->c_lflag;
        for (i = 0; i < NCCS; i++)
                priv->termios.c_cc[i] = tty->termios->c_cc[i];
        priv->cfg.pktlen   = cfg.pktlen;
        priv->cfg.baudrate = cfg.baudrate;
        priv->cfg.databits = cfg.databits;
        priv->cfg.unknown1 = cfg.unknown1;
        priv->cfg.unknown2 = cfg.unknown2;
        spin_unlock_irqrestore(&priv->lock, flags);

        /* READ_ON and urb submission */
        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,
                      klsi_105_read_bulk_callback,
                      port);

        rc = usb_submit_urb(port->read_urb, GFP_KERNEL);
        if (rc) {
                dev_err(&port->dev, "%s - failed submitting read urb, "
                        "error %d\n", __func__, rc);
                retval = rc;
                goto exit;
        }

        rc = usb_control_msg(port->serial->dev,
                             usb_sndctrlpipe(port->serial->dev, 0),
                             KL5KUSB105A_SIO_CONFIGURE,
                             USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
                             KL5KUSB105A_SIO_CONFIGURE_READ_ON,
                             0, /* index */
                             NULL,
                             0,
                             KLSI_TIMEOUT);
        if (rc < 0) {
                dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
                retval = rc;
        } else
                dbg("%s - enabled reading", __func__);

        rc = klsi_105_get_line_state(port, &line_state);
        if (rc >= 0) {
                spin_lock_irqsave(&priv->lock, flags);
                priv->line_state = line_state;
                spin_unlock_irqrestore(&priv->lock, flags);
                dbg("%s - read line state 0x%lx", __func__, line_state);
                retval = 0;
        } else
                retval = rc;

exit:
        return retval;
} /* klsi_105_open */


static void klsi_105_close(struct usb_serial_port *port)
{
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        int rc;

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

        mutex_lock(&port->serial->disc_mutex);
        if (!port->serial->disconnected) {
                /* send READ_OFF */
                rc = usb_control_msg(port->serial->dev,
                                     usb_sndctrlpipe(port->serial->dev, 0),
                                     KL5KUSB105A_SIO_CONFIGURE,
                                     USB_TYPE_VENDOR | USB_DIR_OUT,
                                     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
                                     0, /* index */
                                     NULL, 0,
                                     KLSI_TIMEOUT);
                if (rc < 0)
                        dev_err(&port->dev,
                                "Disabling read failed (error = %d)\n", rc);
        }
        mutex_unlock(&port->serial->disc_mutex);

        /* shutdown our bulk reads and writes */
        usb_kill_urb(port->write_urb);
        usb_kill_urb(port->read_urb);
        /* unlink our write pool */
        /* FIXME */
        /* wgg - do I need this? I think so. */
        usb_kill_urb(port->interrupt_in_urb);
        dev_info(&port->serial->dev->dev,
                 "port stats: %ld bytes in, %ld bytes out\n",
                 priv->bytes_in, priv->bytes_out);
} /* klsi_105_close */


/* We need to write a complete 64-byte data block and encode the
 * number actually sent in the first double-byte, LSB-order. That
 * leaves at most 62 bytes of payload.
 */
#define KLSI_105_DATA_OFFSET    2   /* in the bulk urb data block */


static int klsi_105_write(struct tty_struct *tty,
        struct usb_serial_port *port, const unsigned char *buf, int count)
{
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        int result, size;
        int bytes_sent = 0;

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

        while (count > 0) {
                /* try to find a free urb (write 0 bytes if none) */
                struct urb *urb = NULL;
                unsigned long flags;
                int i;
                /* since the pool is per-port we might not need
                   the spin lock !? */
                spin_lock_irqsave(&priv->lock, flags);
                for (i = 0; i < NUM_URBS; i++) {
                        if (priv->write_urb_pool[i]->status != -EINPROGRESS) {
                                urb = priv->write_urb_pool[i];
                                dbg("%s - using pool URB %d", __func__, i);
                                break;
                        }
                }
                spin_unlock_irqrestore(&priv->lock, flags);

                if (urb == NULL) {
                        dbg("%s - no more free urbs", __func__);
                        goto exit;
                }

                if (urb->transfer_buffer == NULL) {
                        urb->transfer_buffer =
                                kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
                        if (urb->transfer_buffer == NULL) {
                                dev_err(&port->dev,
                                        "%s - no more kernel memory...\n",
                                        __func__);
                                goto exit;
                        }
                }

                size = min(count, port->bulk_out_size - KLSI_105_DATA_OFFSET);
                size = min(size, URB_TRANSFER_BUFFER_SIZE -
                                                        KLSI_105_DATA_OFFSET);

                memcpy(urb->transfer_buffer + KLSI_105_DATA_OFFSET, buf, size);

                /* write payload size into transfer buffer */
                ((__u8 *)urb->transfer_buffer)[0] = (__u8) (size & 0xFF);
                ((__u8 *)urb->transfer_buffer)[1] = (__u8) ((size & 0xFF00)>>8);

                /* set up our urb */
                usb_fill_bulk_urb(urb, port->serial->dev,
                              usb_sndbulkpipe(port->serial->dev,
                                              port->bulk_out_endpointAddress),
                              urb->transfer_buffer,
                              URB_TRANSFER_BUFFER_SIZE,
                              klsi_105_write_bulk_callback,
                              port);

                /* send the data out the bulk port */
                result = usb_submit_urb(urb, GFP_ATOMIC);
                if (result) {
                        dev_err(&port->dev,
                                "%s - failed submitting write urb, error %d\n",
                                __func__, result);
                        goto exit;
                }
                buf += size;
                bytes_sent += size;
                count -= size;
        }
exit:
        /* lockless, but it's for debug info only... */
        priv->bytes_out += bytes_sent;

        return bytes_sent;      /* that's how much we wrote */
} /* klsi_105_write */

static void klsi_105_write_bulk_callback(struct urb *urb)
{
        struct usb_serial_port *port = urb->context;
        int status = urb->status;

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

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

        usb_serial_port_softint(port);
} /* klsi_105_write_bulk_completion_callback */


/* return number of characters currently in the writing process */
static int klsi_105_chars_in_buffer(struct tty_struct *tty)
{
        struct usb_serial_port *port = tty->driver_data;
        int chars = 0;
        int i;
        unsigned long flags;
        struct klsi_105_private *priv = usb_get_serial_port_data(port);

        spin_lock_irqsave(&priv->lock, flags);

        for (i = 0; i < NUM_URBS; ++i) {
                if (priv->write_urb_pool[i]->status == -EINPROGRESS)
                        chars += URB_TRANSFER_BUFFER_SIZE;
        }

        spin_unlock_irqrestore(&priv->lock, flags);

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

static int klsi_105_write_room(struct tty_struct *tty)
{
        struct usb_serial_port *port = tty->driver_data;
        unsigned long flags;
        int i;
        int room = 0;
        struct klsi_105_private *priv = usb_get_serial_port_data(port);

        spin_lock_irqsave(&priv->lock, flags);
        for (i = 0; i < NUM_URBS; ++i) {
                if (priv->write_urb_pool[i]->status != -EINPROGRESS)
                        room += URB_TRANSFER_BUFFER_SIZE;
        }

        spin_unlock_irqrestore(&priv->lock, flags);

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



static void klsi_105_read_bulk_callback(struct urb *urb)
{
        struct usb_serial_port *port = urb->context;
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        struct tty_struct *tty;
        unsigned char *data = urb->transfer_buffer;
        int rc;
        int status = urb->status;

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

        /* The urb might have been killed. */
        if (status) {
                dbg("%s - nonzero read bulk status received: %d", __func__,
                    status);
                return;
        }

        /* The data received is again preceded by a length double-byte in LSB-
         * first order (see klsi_105_write() )
         */
        if (urb->actual_length == 0) {
                /* empty urbs seem to happen, we ignore them */
                /* dbg("%s - emtpy URB", __func__); */
               ;
        } else if (urb->actual_length <= 2) {
                dbg("%s - size %d URB not understood", __func__,
                    urb->actual_length);
                usb_serial_debug_data(debug, &port->dev, __func__,
                                      urb->actual_length, data);
        } else {
                int bytes_sent = ((__u8 *) data)[0] +
                                 ((unsigned int) ((__u8 *) data)[1] << 8);
                tty = tty_port_tty_get(&port->port);
                /* we should immediately resubmit the URB, before attempting
                 * to pass the data on to the tty layer. But that needs locking
                 * against re-entry an then mixed-up data because of
                 * intermixed tty_flip_buffer_push()s
                 * FIXME
                 */
                usb_serial_debug_data(debug, &port->dev, __func__,
                                      urb->actual_length, data);

                if (bytes_sent + 2 > urb->actual_length) {
                        dbg("%s - trying to read more data than available"
                            " (%d vs. %d)", __func__,
                            bytes_sent+2, urb->actual_length);
                        /* cap at implied limit */
                        bytes_sent = urb->actual_length - 2;
                }

                tty_buffer_request_room(tty, bytes_sent);
                tty_insert_flip_string(tty, data + 2, bytes_sent);
                tty_flip_buffer_push(tty);
                tty_kref_put(tty);

                /* again lockless, but debug info only */
                priv->bytes_in += bytes_sent;
        }
        /* 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,
                      klsi_105_read_bulk_callback,
                      port);
        rc = usb_submit_urb(port->read_urb, GFP_ATOMIC);
        if (rc)
                dev_err(&port->dev,
                        "%s - failed resubmitting read urb, error %d\n",
                        __func__, rc);
} /* klsi_105_read_bulk_callback */


static void klsi_105_set_termios(struct tty_struct *tty,
                                 struct usb_serial_port *port,
                                 struct ktermios *old_termios)
{
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        unsigned int iflag = tty->termios->c_iflag;
        unsigned int old_iflag = old_termios->c_iflag;
        unsigned int cflag = tty->termios->c_cflag;
        unsigned int old_cflag = old_termios->c_cflag;
        struct klsi_105_port_settings cfg;
        unsigned long flags;
        speed_t baud;

        /* lock while we are modifying the settings */
        spin_lock_irqsave(&priv->lock, flags);

        /*
         * Update baud rate
         */
        baud = tty_get_baud_rate(tty);

        if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
                /* reassert DTR and (maybe) RTS on transition from B0 */
                if ((old_cflag & CBAUD) == B0) {
                        dbg("%s: baud was B0", __func__);
#if 0
                        priv->control_state |= TIOCM_DTR;
                        /* don't set RTS if using hardware flow control */
                        if (!(old_cflag & CRTSCTS))
                                priv->control_state |= TIOCM_RTS;
                        mct_u232_set_modem_ctrl(serial, priv->control_state);
#endif
                }
        }
        switch (baud) {
        case 0: /* handled below */
                break;
        case 1200:
                priv->cfg.baudrate = kl5kusb105a_sio_b1200;
                break;
        case 2400:
                priv->cfg.baudrate = kl5kusb105a_sio_b2400;
                break;
        case 4800:
                priv->cfg.baudrate = kl5kusb105a_sio_b4800;
                break;
        case 9600:
                priv->cfg.baudrate = kl5kusb105a_sio_b9600;
                break;
        case 19200:
                priv->cfg.baudrate = kl5kusb105a_sio_b19200;
                break;
        case 38400:
                priv->cfg.baudrate = kl5kusb105a_sio_b38400;
                break;
        case 57600:
                priv->cfg.baudrate = kl5kusb105a_sio_b57600;
                break;
        case 115200:
                priv->cfg.baudrate = kl5kusb105a_sio_b115200;
                break;
        default:
                dbg("KLSI USB->Serial converter:"
                    " unsupported baudrate request, using default of 9600");
                        priv->cfg.baudrate = kl5kusb105a_sio_b9600;
                baud = 9600;
                break;
        }
        if ((cflag & CBAUD) == B0) {
                dbg("%s: baud is B0", __func__);
                /* Drop RTS and DTR */
                /* maybe this should be simulated by sending read
                 * disable and read enable messages?
                 */
                ;
#if 0
                priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
                mct_u232_set_modem_ctrl(serial, priv->control_state);
#endif
        }
        tty_encode_baud_rate(tty, baud, baud);

        if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
                /* set the number of data bits */
                switch (cflag & CSIZE) {
                case CS5:
                        dbg("%s - 5 bits/byte not supported", __func__);
                        spin_unlock_irqrestore(&priv->lock, flags);
                        return ;
                case CS6:
                        dbg("%s - 6 bits/byte not supported", __func__);
                        spin_unlock_irqrestore(&priv->lock, flags);
                        return ;
                case CS7:
                        priv->cfg.databits = kl5kusb105a_dtb_7;
                        break;
                case CS8:
                        priv->cfg.databits = kl5kusb105a_dtb_8;
                        break;
                default:
                        dev_err(&port->dev,
                                "CSIZE was not CS5-CS8, using default of 8\n");
                        priv->cfg.databits = kl5kusb105a_dtb_8;
                        break;
                }
        }

        /*
         * Update line control register (LCR)
         */
        if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
            || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
                /* Not currently supported */
                tty->termios->c_cflag &= ~(PARENB|PARODD|CSTOPB);
#if 0
                priv->last_lcr = 0;

                /* set the parity */
                if (cflag & PARENB)
                        priv->last_lcr |= (cflag & PARODD) ?
                                MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
                else
                        priv->last_lcr |= MCT_U232_PARITY_NONE;

                /* set the number of stop bits */
                priv->last_lcr |= (cflag & CSTOPB) ?
                        MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;

                mct_u232_set_line_ctrl(serial, priv->last_lcr);
#endif
                ;
        }
        /*
         * Set flow control: well, I do not really now how to handle DTR/RTS.
         * Just do what we have seen with SniffUSB on Win98.
         */
        if ((iflag & IXOFF) != (old_iflag & IXOFF)
            || (iflag & IXON) != (old_iflag & IXON)
            ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
                /* Not currently supported */
                tty->termios->c_cflag &= ~CRTSCTS;
                /* Drop DTR/RTS if no flow control otherwise assert */
#if 0
                if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
                        priv->control_state |= TIOCM_DTR | TIOCM_RTS;
                else
                        priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
                mct_u232_set_modem_ctrl(serial, priv->control_state);
#endif
                ;
        }
        memcpy(&cfg, &priv->cfg, sizeof(cfg));
        spin_unlock_irqrestore(&priv->lock, flags);

        /* now commit changes to device */
        klsi_105_chg_port_settings(port, &cfg);
} /* klsi_105_set_termios */


#if 0
static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
{
        struct usb_serial_port *port = tty->driver_data;
        struct usb_serial *serial = port->serial;
        struct mct_u232_private *priv =
                                (struct mct_u232_private *)port->private;
        unsigned char lcr = priv->last_lcr;

        dbg("%sstate=%d", __func__, break_state);

        /* LOCKING */
        if (break_state)
                lcr |= MCT_U232_SET_BREAK;

        mct_u232_set_line_ctrl(serial, lcr);
} /* mct_u232_break_ctl */
#endif

static int klsi_105_tiocmget(struct tty_struct *tty, struct file *file)
{
        struct usb_serial_port *port = tty->driver_data;
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
        int rc;
        unsigned long line_state;
        dbg("%s - request, just guessing", __func__);

        rc = klsi_105_get_line_state(port, &line_state);
        if (rc < 0) {
                dev_err(&port->dev,
                        "Reading line control failed (error = %d)\n", rc);
                /* better return value? EAGAIN? */
                return rc;
        }

        spin_lock_irqsave(&priv->lock, flags);
        priv->line_state = line_state;
        spin_unlock_irqrestore(&priv->lock, flags);
        dbg("%s - read line state 0x%lx", __func__, line_state);
        return (int)line_state;
}

static int klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
                             unsigned int set, unsigned int clear)
{
        int retval = -EINVAL;

        dbg("%s", __func__);

/* if this ever gets implemented, it should be done something like this:
        struct usb_serial *serial = port->serial;
        struct klsi_105_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
        int control;

        spin_lock_irqsave (&priv->lock, flags);
        if (set & TIOCM_RTS)
                priv->control_state |= TIOCM_RTS;
        if (set & TIOCM_DTR)
                priv->control_state |= TIOCM_DTR;
        if (clear & TIOCM_RTS)
                priv->control_state &= ~TIOCM_RTS;
        if (clear & TIOCM_DTR)
                priv->control_state &= ~TIOCM_DTR;
        control = priv->control_state;
        spin_unlock_irqrestore (&priv->lock, flags);
        retval = mct_u232_set_modem_ctrl(serial, control);
*/
        return retval;
}

static void klsi_105_throttle(struct tty_struct *tty)
{
        struct usb_serial_port *port = tty->driver_data;
        dbg("%s - port %d", __func__, port->number);
        usb_kill_urb(port->read_urb);
}

static void klsi_105_unthrottle(struct tty_struct *tty)
{
        struct usb_serial_port *port = tty->driver_data;
        int result;

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

        port->read_urb->dev = port->serial->dev;
        result = usb_submit_urb(port->read_urb, GFP_KERNEL);
        if (result)
                dev_err(&port->dev,
                        "%s - failed submitting read urb, error %d\n",
                        __func__, result);
}



static int __init klsi_105_init(void)
{
        int retval;
        retval = usb_serial_register(&kl5kusb105d_device);
        if (retval)
                goto failed_usb_serial_register;
        retval = usb_register(&kl5kusb105d_driver);
        if (retval)
                goto failed_usb_register;

        printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
               DRIVER_DESC "\n");
        return 0;
failed_usb_register:
        usb_serial_deregister(&kl5kusb105d_device);
failed_usb_serial_register:
        return retval;
}


static void __exit klsi_105_exit(void)
{
        usb_deregister(&kl5kusb105d_driver);
        usb_serial_deregister(&kl5kusb105d_device);
}


module_init(klsi_105_init);
module_exit(klsi_105_exit);

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


module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "enable extensive debugging messages");

/* vim: set sts=8 ts=8 sw=8: */