digi_acceleport.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

	int ret,data_len,new_len;
	digi_port_t *priv = (digi_port_t *)(port->private);
	unsigned char *data = port->write_urb->transfer_buffer;
	unsigned char user_buf[64];	/* 64 bytes is max USB bulk packet */
	unsigned long flags = 0;


dbg( "digi_write: TOP: port=%d, count=%d, from_user=%d, in_interrupt=%d",
priv->dp_port_num, count, from_user, in_interrupt() );

	/* copy user data (which can sleep) before getting spin lock */
	count = min( count, port->bulk_out_size-2 );
	count = min( 64, count);
	if( from_user && copy_from_user( user_buf, buf, count ) ) {
		return( -EFAULT );
	}

	/* be sure only one write proceeds at a time */
	/* there are races on the port private buffer */
	/* and races to check write_urb->status */
	spin_lock_irqsave( &priv->dp_port_lock, flags );

	/* wait for urb status clear to submit another urb */
	if( port->write_urb->status == -EINPROGRESS
	|| priv->dp_write_urb_in_use ) {

		/* buffer data if count is 1 (probably put_char) if possible */
		if( count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE ) {
			priv->dp_out_buf[priv->dp_out_buf_len++]
				= *(from_user ? user_buf : buf);
			new_len = 1;
		} else {
			new_len = 0;
		}

		spin_unlock_irqrestore( &priv->dp_port_lock, flags );

		return( new_len );

	}

	/* allow space for any buffered data and for new data, up to */
	/* transfer buffer size - 2 (for command and length bytes) */
	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
	data_len = new_len + priv->dp_out_buf_len;

	if( data_len == 0 ) {
		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
		return( 0 );
	}

	port->write_urb->transfer_buffer_length = data_len+2;
	port->write_urb->dev = port->serial->dev;

	*data++ = DIGI_CMD_SEND_DATA;
	*data++ = data_len;

	/* copy in buffered data first */
	memcpy( data, priv->dp_out_buf, priv->dp_out_buf_len );
	data += priv->dp_out_buf_len;

	/* copy in new data */
	memcpy( data, from_user ? user_buf : buf, new_len );

	if( (ret=usb_submit_urb(port->write_urb)) == 0 ) {
		priv->dp_write_urb_in_use = 1;
		ret = new_len;
		priv->dp_out_buf_len = 0;
	}

	/* return length of new data written, or error */
	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
	if( ret < 0 ) {
		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
			ret, priv->dp_port_num );
	}

dbg( "digi_write: returning %d", ret );
	return( ret );

} 


static void digi_write_bulk_callback( struct urb *urb )
{

	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial;
	digi_port_t *priv;
	int ret = 0;


dbg( "digi_write_bulk_callback: TOP, urb->status=%d", urb->status );

	/* port and serial sanity check */
	if( port == NULL || (priv=(digi_port_t *)(port->private)) == NULL ) {
		err( __FUNCTION__ ": port or port->private is NULL, status=%d",
			urb->status );
		return;
	}
	serial = port->serial;
	if( serial == NULL || serial->private == NULL ) {
		err( __FUNCTION__ ": serial or serial->private is NULL, status=%d", urb->status );
		return;
	}

	/* handle oob callback */
	if( priv->dp_port_num
	== ((digi_serial_t *)(serial->private))->ds_oob_port_num ) {
		dbg( "digi_write_bulk_callback: oob callback" );
		spin_lock( &priv->dp_port_lock );
		priv->dp_write_urb_in_use = 0;
		wake_up_interruptible( &port->write_wait );
		spin_unlock( &priv->dp_port_lock );
		return;
	}

	/* further sanity checks */
	if( port_paranoia_check( port, __FUNCTION__ )
	|| serial_paranoia_check( serial, __FUNCTION__ ) )
		return;

	/* try to send any buffered data on this port, if it is open */
	spin_lock( &priv->dp_port_lock );
	priv->dp_write_urb_in_use = 0;
	if( priv->dp_open_count && port->write_urb->status != -EINPROGRESS
	&& priv->dp_out_buf_len > 0 ) {

		*((unsigned char *)(port->write_urb->transfer_buffer))
			= (unsigned char)DIGI_CMD_SEND_DATA;
		*((unsigned char *)(port->write_urb->transfer_buffer)+1)
			= (unsigned char)priv->dp_out_buf_len;

		port->write_urb->transfer_buffer_length
			= priv->dp_out_buf_len+2;
		port->write_urb->dev = serial->dev;

		memcpy( port->write_urb->transfer_buffer+2, priv->dp_out_buf,
			priv->dp_out_buf_len );

		if( (ret=usb_submit_urb(port->write_urb)) == 0 ) {
			priv->dp_write_urb_in_use = 1;
			priv->dp_out_buf_len = 0;
		}

	}

	/* wake up processes sleeping on writes immediately */
	digi_wakeup_write( port );

	/* also queue up a wakeup at scheduler time, in case we */
	/* lost the race in write_chan(). */
	MOD_INC_USE_COUNT;
	if (schedule_task(&priv->dp_wakeup_task) == 0)
		MOD_DEC_USE_COUNT;

	spin_unlock( &priv->dp_port_lock );

	if( ret ) {
		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
			ret, priv->dp_port_num );
	}

}


static int digi_write_room( struct usb_serial_port *port )
{

	int room;
	digi_port_t *priv = (digi_port_t *)(port->private);
	unsigned long flags = 0;


	spin_lock_irqsave( &priv->dp_port_lock, flags );

	if( port->write_urb->status == -EINPROGRESS
	|| priv->dp_write_urb_in_use )
		room = 0;
	else
		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;

	spin_unlock_irqrestore( &priv->dp_port_lock, flags );

dbg( "digi_write_room: port=%d, room=%d", priv->dp_port_num, room );
	return( room );

}


static int digi_chars_in_buffer( struct usb_serial_port *port )
{

	digi_port_t *priv = (digi_port_t *)(port->private);


	if( port->write_urb->status == -EINPROGRESS
	|| priv->dp_write_urb_in_use ) {
dbg( "digi_chars_in_buffer: port=%d, chars=%d", priv->dp_port_num, port->bulk_out_size - 2 );
		/* return( port->bulk_out_size - 2 ); */
		return( 256 );
	} else {
dbg( "digi_chars_in_buffer: port=%d, chars=%d", priv->dp_port_num, priv->dp_out_buf_len );
		return( priv->dp_out_buf_len );
	}

}


static int digi_open( struct usb_serial_port *port, struct file *filp )
{

	int ret;
	unsigned char buf[32];
	digi_port_t *priv = (digi_port_t *)(port->private);
	struct termios not_termios;
	unsigned long flags = 0;


dbg( "digi_open: TOP: port=%d, active=%d, open_count=%d", priv->dp_port_num, port->active, priv->dp_open_count );

	/* be sure the device is started up */
	if( digi_startup_device( port->serial ) != 0 )
		return( -ENXIO );

	spin_lock_irqsave( &priv->dp_port_lock, flags );

	/* don't wait on a close in progress for non-blocking opens */
	if( priv->dp_in_close && (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
		return( -EAGAIN );
	}

	/* inc module use count before sleeping to wait for closes */
	++priv->dp_open_count;
	MOD_INC_USE_COUNT;

	/* wait for a close in progress to finish */
	while( priv->dp_in_close ) {
		cond_wait_interruptible_timeout_irqrestore(
			&priv->dp_close_wait, DIGI_RETRY_TIMEOUT,
			&priv->dp_port_lock, flags );
		if( signal_pending(current) ) {
			--priv->dp_open_count;
			MOD_DEC_USE_COUNT;
			return( -EINTR );
		}
		spin_lock_irqsave( &priv->dp_port_lock, flags );
	}

	/* if port is already open, just return */
	/* be sure exactly one open proceeds */
	if( port->active ) {
		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
		return( 0 );
	}

	/* first open, mark port as active */
	port->active = 1;
	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
 
	/* read modem signals automatically whenever they change */
	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
	buf[1] = priv->dp_port_num;
	buf[2] = DIGI_ENABLE;
	buf[3] = 0;

	/* flush fifos */
	buf[4] = DIGI_CMD_IFLUSH_FIFO;
	buf[5] = priv->dp_port_num;
	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
	buf[7] = 0;

	if( (ret=digi_write_oob_command( port, buf, 8, 1 )) != 0 )
		dbg( "digi_open: write oob failed, ret=%d", ret );

	/* set termios settings */
	not_termios.c_cflag = ~port->tty->termios->c_cflag;
	not_termios.c_iflag = ~port->tty->termios->c_iflag;
	digi_set_termios( port, &not_termios );

	/* set DTR and RTS */
	digi_set_modem_signals( port, TIOCM_DTR|TIOCM_RTS, 1 );

	return( 0 );

}


static void digi_close( struct usb_serial_port *port, struct file *filp )
{

	int ret;
	unsigned char buf[32];
	struct tty_struct *tty = port->tty;
	digi_port_t *priv = (digi_port_t *)port->private;
	unsigned long flags = 0;


dbg( "digi_close: TOP: port=%d, active=%d, open_count=%d", priv->dp_port_num, port->active, priv->dp_open_count );


	/* do cleanup only after final close on this port */
	spin_lock_irqsave( &priv->dp_port_lock, flags );
	if( priv->dp_open_count > 1 ) {
		--priv->dp_open_count;
		MOD_DEC_USE_COUNT;
		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
		return;
	} else if( priv->dp_open_count <= 0 ) {
		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
		return;
	}
	priv->dp_in_close = 1;
	spin_unlock_irqrestore( &priv->dp_port_lock, flags );

	/* tell line discipline to process only XON/XOFF */
        tty->closing = 1;

	/* wait for output to drain */
	if( (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
		tty_wait_until_sent( tty, DIGI_CLOSE_TIMEOUT );
	}

	/* flush driver and line discipline buffers */
	if( tty->driver.flush_buffer )
		tty->driver.flush_buffer( tty );
	if( tty->ldisc.flush_buffer )
		tty->ldisc.flush_buffer( tty );

	if (port->serial->dev) {
		/* wait for transmit idle */
		if( (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
			digi_transmit_idle( port, DIGI_CLOSE_TIMEOUT );
		}

		/* drop DTR and RTS */
		digi_set_modem_signals( port, 0, 0 );

		/* disable input flow control */
		buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
		buf[1] = priv->dp_port_num;
		buf[2] = DIGI_DISABLE;
		buf[3] = 0;

		/* disable output flow control */
		buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
		buf[5] = priv->dp_port_num;
		buf[6] = DIGI_DISABLE;
		buf[7] = 0;

		/* disable reading modem signals automatically */
		buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
		buf[9] = priv->dp_port_num;
		buf[10] = DIGI_DISABLE;
		buf[11] = 0;

		/* disable receive */
		buf[12] = DIGI_CMD_RECEIVE_ENABLE;
		buf[13] = priv->dp_port_num;
		buf[14] = DIGI_DISABLE;
		buf[15] = 0;

		/* flush fifos */
		buf[16] = DIGI_CMD_IFLUSH_FIFO;
		buf[17] = priv->dp_port_num;
		buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
		buf[19] = 0;

		if( (ret=digi_write_oob_command( port, buf, 20, 0 )) != 0 )
			dbg( "digi_close: write oob failed, ret=%d", ret );

		/* wait for final commands on oob port to complete */
		interruptible_sleep_on_timeout( &priv->dp_flush_wait,
			DIGI_CLOSE_TIMEOUT );

		/* shutdown any outstanding bulk writes */
		usb_unlink_urb (port->write_urb);
	}

	tty->closing = 0;

	spin_lock_irqsave( &priv->dp_port_lock, flags );
	port->active = 0;
	priv->dp_write_urb_in_use = 0;
	priv->dp_in_close = 0;
	--priv->dp_open_count;
	MOD_DEC_USE_COUNT;
	wake_up_interruptible( &priv->dp_close_wait );
	spin_unlock_irqrestore( &priv->dp_port_lock, flags );

dbg( "digi_close: done" );
}


/*
*  Digi Startup Device
*
*  Starts reads on all ports.  Must be called AFTER startup, with
*  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
*/

static int digi_startup_device( struct usb_serial *serial )
{

	int i,ret = 0;
	digi_serial_t *serial_priv = (digi_serial_t *)serial->private;
	struct usb_serial_port *port;


	/* be sure this happens exactly once */
	spin_lock( &serial_priv->ds_serial_lock );
	if( serial_priv->ds_device_started ) {
		spin_unlock( &serial_priv->ds_serial_lock );
		return( 0 );
	}
	serial_priv->ds_device_started = 1;
	spin_unlock( &serial_priv->ds_serial_lock );

	/* start reading from each bulk in endpoint for the device */
	/* set USB_DISABLE_SPD flag for write bulk urbs */