Import 2.3.4pre3

[davej-history.git] / drivers / net / irda / irtty.c

/*********************************************************************
 *                
 * Filename:      irtty.c
 * Version:       1.1
 * Description:   IrDA line discipline implementation
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Tue Dec  9 21:18:38 1997
 * Modified at:   Mon May 10 15:45:50 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * Sources:       slip.c by Laurence Culhane,   <loz@holmes.demon.co.uk>
 *                          Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
 * 
 *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
 *      
 *     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.
 *  
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is 
 *     provided "AS-IS" and at no charge.
 *     
 ********************************************************************/    

#include <linux/config.h>
#include <linux/module.h>
#include <asm/uaccess.h>
#include <linux/kernel.h>
#include <linux/tty.h>
#include <asm/segment.h>
#include <linux/init.h>

#include <net/irda/irda.h>
#include <net/irda/irtty.h>
#include <net/irda/wrapper.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/irda_device.h>

static hashbin_t *irtty = NULL;

static struct tty_ldisc irda_ldisc;

static int qos_mtt_bits = 0x03;      /* 5 ms or more */

static int  irtty_hard_xmit(struct sk_buff *skb, struct device *dev);
static void irtty_wait_until_sent(struct irda_device *driver);
static int  irtty_is_receiving(struct irda_device *idev);
static void irtty_set_dtr_rts(struct irda_device *idev, int dtr, int rts);
static int  irtty_raw_write(struct irda_device *idev, __u8 *buf, int len);
static int  irtty_net_init(struct device *dev);
static int  irtty_net_open(struct device *dev);
static int  irtty_net_close(struct device *dev);

static int  irtty_open(struct tty_struct *tty);
static void irtty_close(struct tty_struct *tty);
static int  irtty_ioctl(struct tty_struct *, void *, int, void *);
static int  irtty_receive_room(struct tty_struct *tty);
static void irtty_change_speed(struct irda_device *dev, int baud);
static void irtty_write_wakeup(struct tty_struct *tty);

static void irtty_receive_buf(struct tty_struct *, const unsigned char *, 
                              char *, int);
char *driver_name = "irtty";

__initfunc(int irtty_init(void))
{
        int status;
        
        irtty = hashbin_new( HB_LOCAL);
        if ( irtty == NULL) {
                printk( KERN_WARNING "IrDA: Can't allocate irtty hashbin!\n");
                return -ENOMEM;
        }

        /* Fill in our line protocol discipline, and register it */
        memset(&irda_ldisc, 0, sizeof( irda_ldisc));

        irda_ldisc.magic = TTY_LDISC_MAGIC;
        irda_ldisc.name  = "irda";
        irda_ldisc.flags = 0;
        irda_ldisc.open  = irtty_open;
        irda_ldisc.close = irtty_close;
        irda_ldisc.read  = NULL;
        irda_ldisc.write = NULL;
        irda_ldisc.ioctl = (int (*)(struct tty_struct *, struct file *,
                                    unsigned int, unsigned long)) irtty_ioctl;
        irda_ldisc.poll  = NULL;
        irda_ldisc.receive_buf  = irtty_receive_buf;
        irda_ldisc.receive_room = irtty_receive_room;
        irda_ldisc.write_wakeup = irtty_write_wakeup;
        
        if (( status = tty_register_ldisc(N_IRDA, &irda_ldisc)) != 0)  {
                printk(KERN_ERR 
                       "IrDA: can't register line discipline (err = %d)\n", 
                       status);
        }
        
        return status;
}

/* 
 *  Function irtty_cleanup ( )
 *
 *    Called when the irda module is removed. Here we remove all instances
 *    of the driver, and the master array.
 */
#ifdef MODULE
static void irtty_cleanup(void) 
{
        int ret;
        
        /*
         *  Unregister tty line-discipline
         */
        if ((ret = tty_register_ldisc(N_IRDA, NULL))) {
                ERROR(__FUNCTION__ 
                      "(), can't unregister line discipline (err = %d)\n",
                      ret);
        }

        /*
         *  The TTY should care of deallocating the instances by using the
         *  callback to irtty_close(), therefore we do give any deallocation
         *  function to hashbin_destroy().
         */
        hashbin_delete(irtty, NULL);
}
#endif /* MODULE */

/* 
 *  Function irtty_open(tty)
 *
 *    This function is called by the TTY module when the IrDA line
 *    discipline is called for.  Because we are sure the tty line exists,
 *    we only have to link it to a free IrDA channel.  
 */
static int irtty_open(struct tty_struct *tty) 
{
        struct irtty_cb *self;
        char name[16];
        
        ASSERT(tty != NULL, return -EEXIST;);

        /* First make sure we're not already connected. */
        self = (struct irtty_cb *) tty->disc_data;
        if (self != NULL && self->magic == IRTTY_MAGIC)
                return -EEXIST;
        
        /*
         *  Allocate new instance of the driver
         */
        self = kmalloc(sizeof(struct irtty_cb), GFP_KERNEL);
        if (self == NULL) {
                printk(KERN_ERR "IrDA: Can't allocate memory for "
                       "IrDA control block!\n");
                return -ENOMEM;
        }
        memset(self, 0, sizeof(struct irtty_cb));
        
        self->tty = tty;
        tty->disc_data = self;

        /* Give self a name */
        sprintf(name, "%s%d", tty->driver.name,
                MINOR(tty->device) - tty->driver.minor_start +
                tty->driver.name_base);
        
        /* hashbin_insert( irtty, (QUEUE*) self, 0, self->name); */
        hashbin_insert(irtty, (QUEUE*) self, (int) self, NULL);

        if (tty->driver.flush_buffer)
                tty->driver.flush_buffer(tty);
        
        if (tty->ldisc.flush_buffer)
                tty->ldisc.flush_buffer(tty);
        
        self->magic = IRTTY_MAGIC;

        /*
         *  Initialize driver
         */
        self->idev.rx_buff.state = OUTSIDE_FRAME;

        /* 
         *  Initialize QoS capabilities, we fill in all the stuff that
         *  we support. Be careful not to place any restrictions on values
         *  that are not device dependent (such as link disconnect time) so
         *  this parameter can be set by IrLAP (or the user) instead. DB
         */
        irda_init_max_qos_capabilies(&self->idev.qos);

        /* The only value we must override it the baudrate */
        self->idev.qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|
                IR_115200;
        self->idev.qos.min_turn_time.bits = qos_mtt_bits;
        self->idev.flags = IFF_SIR | IFF_PIO;
        irda_qos_bits_to_value(&self->idev.qos);

        /* Specify which buffer allocation policy we need */
        self->idev.rx_buff.flags = GFP_KERNEL;
        self->idev.tx_buff.flags = GFP_KERNEL;

        /* Specify how much memory we want */
        self->idev.rx_buff.truesize = 4000; 
        self->idev.tx_buff.truesize = 4000;

        /* Initialize callbacks */
        self->idev.change_speed    = irtty_change_speed;
        self->idev.is_receiving    = irtty_is_receiving;
        self->idev.set_dtr_rts     = irtty_set_dtr_rts;
        self->idev.raw_write       = irtty_raw_write;
        self->idev.wait_until_sent = irtty_wait_until_sent;

        /* Override the network functions we need to use */
        self->idev.netdev.init            = irtty_net_init;
        self->idev.netdev.hard_start_xmit = irtty_hard_xmit;
        self->idev.netdev.open            = irtty_net_open;
        self->idev.netdev.stop            = irtty_net_close;

        /* Open the IrDA device */
        irda_device_open(&self->idev, name, self);

        MOD_INC_USE_COUNT;

        return 0;
}

/* 
 *  Function irtty_close (tty)
 *
 *    Close down a IrDA channel. This means flushing out any pending queues,
 *    and then restoring the TTY line discipline to what it was before it got
 *    hooked to IrDA (which usually is TTY again).  
 */
static void irtty_close(struct tty_struct *tty) 
{
        struct irtty_cb *self = (struct irtty_cb *) tty->disc_data;
        
        /* First make sure we're connected. */
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRTTY_MAGIC, return;);

        /* Remove driver */
        irda_device_close(&self->idev);

        /* Stop tty */
        tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
        tty->disc_data = 0;

        self->tty = NULL;
        self->magic = 0;
        
        self = hashbin_remove(irtty, (int) self, NULL);
        
        if (self != NULL)
                kfree(self);

        MOD_DEC_USE_COUNT;
}

/*
 * Function irtty_stop_receiver (irda_device, stop)
 *
 *    
 *
 */
static void irtty_stop_receiver(struct irda_device *idev, int stop)
{
        struct termios old_termios;
        struct irtty_cb *self;
        int cflag;

        self = (struct irtty_cb *) idev->priv;

        old_termios = *(self->tty->termios);
        cflag = self->tty->termios->c_cflag;
        
        if (stop)
                cflag &= ~CREAD;
        else
                cflag |= CREAD;

        self->tty->termios->c_cflag = cflag;
        self->tty->driver.set_termios(self->tty, &old_termios);
}

/* 
 *  Function irtty_change_speed (self, baud)
 *
 *    Change the speed of the serial port. The driver layer must check that
 *    all transmission has finished using the irtty_wait_until_sent() 
 *    function.
 */
static void irtty_change_speed(struct irda_device *idev, int baud) 
{
        struct termios old_termios;
        struct irtty_cb *self;
        int cflag;

        DEBUG(4,__FUNCTION__ "(), <%ld>\n", jiffies); 

        ASSERT(idev != NULL, return;);
        ASSERT(idev->magic == IRDA_DEVICE_MAGIC, return;);

        self = (struct irtty_cb *) idev->priv;

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRTTY_MAGIC, return;);

        old_termios = *(self->tty->termios);
        cflag = self->tty->termios->c_cflag;

        cflag &= ~CBAUD;

        DEBUG(4, __FUNCTION__ "(), Setting speed to %d\n", baud);

        switch (baud) {
        case 1200:
                cflag |= B1200;
                break;
        case 2400:
                cflag |= B2400;
                break;
        case 4800:
                cflag |= B4800;
                break;
        case 19200:
                cflag |= B19200;
                break;
        case 38400:
                cflag |= B38400;
                break;
        case 57600:
                cflag |= B57600;
                break;
        case 115200:
                cflag |= B115200;
                break;
        case 9600:
        default:
                cflag |= B9600;
                break;
        }       

        self->tty->termios->c_cflag = cflag;
        self->tty->driver.set_termios(self->tty, &old_termios);
}

/*
 * Function irtty_ioctl (tty, file, cmd, arg)
 *
 *     The Swiss army knife of system calls :-)
 *
 */
static int irtty_ioctl(struct tty_struct *tty, void *file, int cmd, void *arg)
{
        struct irtty_cb *self;
        int err = 0;
        int size = _IOC_SIZE(cmd);

        self = (struct irtty_cb *) tty->disc_data;

        ASSERT(self != NULL, return -ENODEV;);
        ASSERT(self->magic == IRTTY_MAGIC, return -EBADR;);

        if (_IOC_DIR(cmd) & _IOC_READ)
                err = verify_area( VERIFY_WRITE, (void *) arg, size);
        else if (_IOC_DIR(cmd) & _IOC_WRITE)
                err = verify_area( VERIFY_READ, (void *) arg, size);
        if (err)
                return err;
        
        switch(cmd) {
        case TCGETS:
        case TCGETA:
                return n_tty_ioctl(tty, (struct file *) file, cmd, 
                                   (unsigned long) arg);
                break;
        case IRTTY_IOCTDONGLE:
                /* Initialize dongle */
                irda_device_init_dongle(&self->idev, (int) arg);
                break;
        default:
                return -ENOIOCTLCMD;
        }
        return 0;
}

/* 
 *  Function irtty_receive_buf( tty, cp, count)
 *
 *    Handle the 'receiver data ready' interrupt.  This function is called
 *    by the 'tty_io' module in the kernel when a block of IrDA data has
 *    been received, which can now be decapsulated and delivered for
 *    further processing 
 */
static void irtty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
                              char *fp, int count) 
{
        struct irtty_cb *self = (struct irtty_cb *) tty->disc_data;

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRTTY_MAGIC, return;);
        
        /* Read the characters out of the buffer */
        while (count--) {
                /* 
                 *  Characters received with a parity error, etc?
                 */
                if (fp && *fp++) { 
                        DEBUG( 0, "Framing or parity error!\n");
                        irda_device_set_media_busy( &self->idev, TRUE);

                        cp++;
                        continue;
                }
                /* Unwrap and destuff one byte */
                async_unwrap_char(&self->idev, *cp++);
        }
}

/*
 * Function irtty_hard_xmit (skb, dev)
 *
 *    Transmit frame
 *
 */
static int irtty_hard_xmit(struct sk_buff *skb, struct device *dev)
{
        struct irtty_cb *self;
        struct irda_device *idev;
        int actual = 0;

        idev = (struct irda_device *) dev->priv;

        ASSERT(idev != NULL, return 0;);
        ASSERT(idev->magic == IRDA_DEVICE_MAGIC, return -1;);
        
        self = (struct irtty_cb *) idev->priv;

        ASSERT(self != NULL, return 0;);
        ASSERT(self->magic == IRTTY_MAGIC, return 0;);

        /* Lock transmit buffer */
        if (irda_lock((void *) &dev->tbusy) == FALSE)
                return -EBUSY;
        
        /* Init tx buffer*/
        idev->tx_buff.data = idev->tx_buff.head;
        
        /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
        idev->tx_buff.len = async_wrap_skb(skb, idev->tx_buff.data, 
                                           idev->tx_buff.truesize); 

        self->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);

        dev->trans_start = jiffies;

        if (self->tty->driver.write)
                actual = self->tty->driver.write(self->tty, 0, 
                                                 idev->tx_buff.data, 
                                                 idev->tx_buff.len);

        /* Hide the part we just transmitted */
        idev->tx_buff.data += actual;
        idev->tx_buff.len -= actual;

        idev->stats.tx_packets++;
        idev->stats.tx_bytes += idev->tx_buff.len;
#if 0
        /* 
         *  Did we transmit the whole frame? Commented out for now since
         *  I must check if this optimalization really works. DB.
         */
        if ((idev->tx_buff.len) == 0) {
                DEBUG( 4, "irtty_xmit_buf: finished with frame!\n");
                self->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
                irda_unlock( &self->tbusy);
        }
#endif
        dev_kfree_skb(skb);

        return 0;
}

/*
 * Function irtty_receive_room (tty)
 *
 *    Used by the TTY to find out how much data we can receive at a time
 * 
*/
static int irtty_receive_room(struct tty_struct *tty) 
{
        DEBUG(0, __FUNCTION__ "()\n");
        return 65536;  /* We can handle an infinite amount of data. :-) */
}

/*
 * Function irtty_write_wakeup (tty)
 *
 *    Called by the driver when there's room for more data.  If we have
 *    more packets to send, we send them here.
 *
 */
static void irtty_write_wakeup(struct tty_struct *tty) 
{
        struct irtty_cb *self = (struct irtty_cb *) tty->disc_data;
        struct irda_device *idev;
        int actual = 0;
        
        /* 
         *  First make sure we're connected. 
         */
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRTTY_MAGIC, return;);

        idev = &self->idev;

        /* Finished with frame?  */
        if (idev->tx_buff.len > 0)  {
                /* Write data left in transmit buffer */
                actual = tty->driver.write(tty, 0, idev->tx_buff.data, 
                                           idev->tx_buff.len);

                idev->tx_buff.data += actual;
                idev->tx_buff.len  -= actual;
        } else {                
                /* 
                 *  Now serial buffer is almost free & we can start 
                 *  transmission of another packet 
                 */
                DEBUG(5, __FUNCTION__ "(), finished with frame!\n");
                
                tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);

                idev->netdev.tbusy = 0; /* Unlock */
                        
                /* Tell network layer that we want more frames */
                mark_bh(NET_BH);
        }
}

/*
 * Function irtty_is_receiving (idev)
 *
 *    Return TRUE is we are currently receiving a frame
 *
 */
static int irtty_is_receiving(struct irda_device *idev)
{
        return (idev->rx_buff.state != OUTSIDE_FRAME);
}

/*
 * Function irtty_change_speed_ready (idev)
 *
 *    Are we completely finished with transmitting frames so its possible
 *    to change the speed of the serial port. Warning this function must
 *    be called with a process context!
 */
static void irtty_wait_until_sent(struct irda_device *idev)
{
        struct irtty_cb *self = (struct irtty_cb *) idev->priv;

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRTTY_MAGIC, return;);
        
        DEBUG(4, "Chars in buffer %d\n", 
              self->tty->driver.chars_in_buffer(self->tty));
        
        tty_wait_until_sent(self->tty, 0);
}

/*
 * Function irtty_set_dtr_rts (tty, dtr, rts)
 *
 *    This function can be used by dongles etc. to set or reset the status
 *    of the dtr and rts lines
 */
static void irtty_set_dtr_rts(struct irda_device *idev, int dtr, int rts)
{
        struct tty_struct *tty;
        struct irtty_cb *self;
        mm_segment_t fs;
        int arg = 0;

        self = (struct irtty_cb *) idev->priv;

        tty = self->tty;

#ifdef TIOCM_OUT2 /* Not defined for ARM */
        arg = TIOCM_OUT2;
#endif
        if (rts)
                arg |= TIOCM_RTS;
        if (dtr)
                arg |= TIOCM_DTR;

        /*
         *  The ioctl() function, or actually set_modem_info() in serial.c
         *  expects a pointer to the argument in user space. To hack us
         *  around this, we use the set_fs() function to fool the routines 
         *  that check if they are called from user space. We also need 
         *  to send a pointer to the argument so get_user() gets happy. DB.
         */

        fs = get_fs();
        set_fs(get_ds());
        
        if (tty->driver.ioctl(tty, NULL, TIOCMSET, (unsigned long) &arg)) { 
                ERROR(__FUNCTION__ "(), error doing ioctl!\n");
        }
        set_fs(fs);
}

static int irtty_raw_write(struct irda_device *idev, __u8 *buf, int len)
{
        struct irtty_cb *self;
        int actual = 0;

        ASSERT(idev != NULL, return 0;);
        ASSERT(idev->magic == IRDA_DEVICE_MAGIC, return -1;);
        
        self = (struct irtty_cb *) idev->priv;

        ASSERT(self != NULL, return 0;);
        ASSERT(self->magic == IRTTY_MAGIC, return 0;);

        if (self->tty->driver.write)
                actual = self->tty->driver.write(self->tty, 0, buf, len);

        return actual;
}

static int irtty_net_init(struct device *dev)
{
        /* Set up to be a normal IrDA network device driver */
        irda_device_setup(dev);

        /* Insert overrides below this line! */

        return 0;
}

static int irtty_net_open(struct device *dev)
{
        ASSERT(dev != NULL, return -1;);

        /* Ready to play! */
        dev->tbusy = 0;
        dev->interrupt = 0;
        dev->start = 1;

        MOD_INC_USE_COUNT;

        return 0;
}

static int irtty_net_close(struct device *dev)
{
        ASSERT(dev != NULL, return -1;);
        
        /* Stop device */
        dev->tbusy = 1;
        dev->start = 0;

        MOD_DEC_USE_COUNT;

        return 0;
}

#ifdef MODULE

MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
MODULE_DESCRIPTION("IrDA TTY device driver");

MODULE_PARM(qos_mtt_bits, "i");

/*
 * Function init_module (void)
 *
 *    Initialize IrTTY module
 *
 */
int init_module(void)
{
        return irtty_init();
}

/*
 * Function cleanup_module (void)
 *
 *    Cleanup IrTTY module
 *
 */
void cleanup_module(void)
{
        irtty_cleanup();
}

#endif /* MODULE */