ftdi_sio.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

		usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
				FTDI_SIO_RESET_REQUEST, FTDI_SIO_RESET_REQUEST_TYPE, 
				FTDI_SIO_RESET_SIO, 
				0, buf, 0, WDR_TIMEOUT);

		/* Setup termios defaults. According to tty_io.c the 
		   settings are driver specific */
		port->tty->termios->c_cflag =
			B9600 | CS8 | CREAD | HUPCL | CLOCAL;

		/* ftdi_sio_set_termios  will send usb control messages */
		ftdi_sio_set_termios(port, &tmp_termios);	

		/* Turn on RTS and DTR since we are not flow controlling by default */
		if (set_dtr(serial->dev, usb_sndctrlpipe(serial->dev, 0),HIGH) < 0) {
			err(__FUNCTION__ " Error from DTR HIGH urb");
		}
		if (set_rts(serial->dev, usb_sndctrlpipe(serial->dev, 0),HIGH) < 0){
			err(__FUNCTION__ " Error from RTS HIGH urb");
		}
	
		/* Start reading from the device */
		FILL_BULK_URB(port->read_urb, serial->dev, 
			      usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
			      port->read_urb->transfer_buffer, port->read_urb->transfer_buffer_length,
			      ftdi_sio_read_bulk_callback, port);
		result = usb_submit_urb(port->read_urb);
		if (result)
			err(__FUNCTION__ " - failed submitting read urb, error %d", result);
	}

	up (&port->sem);
	return result;
} /* ftdi_sio_open */


static void ftdi_sio_close (struct usb_serial_port *port, struct file *filp)
{ /* ftdi_sio_close */
	struct usb_serial *serial = port->serial; /* Checked in usbserial.c */
	unsigned int c_cflag = port->tty->termios->c_cflag;
	char buf[1];

	dbg( __FUNCTION__);

	down (&port->sem);
	--port->open_count;

	if (port->open_count <= 0) {
		if (serial->dev) {
			if (c_cflag & HUPCL){
				/* Disable flow control */
				if (usb_control_msg(serial->dev, 
						    usb_sndctrlpipe(serial->dev, 0),
						    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
						    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
						    0, 0, buf, 0, WDR_TIMEOUT) < 0) {
					err("error from flowcontrol urb");
				}	    

				/* drop DTR */
				if (set_dtr(serial->dev, usb_sndctrlpipe(serial->dev, 0), LOW) < 0){
					err("Error from DTR LOW urb");
				}
				/* drop RTS */
				if (set_rts(serial->dev, usb_sndctrlpipe(serial->dev, 0),LOW) < 0) {
					err("Error from RTS LOW urb");
				}	
			} /* Note change no line is hupcl is off */

			/* shutdown our bulk reads and writes */
			/* ***CHECK*** behaviour when there is nothing queued */
			usb_unlink_urb (port->write_urb);
			usb_unlink_urb (port->read_urb);
		}
		port->active = 0;
		port->open_count = 0;
	} else {  
		/* Send a HUP if necessary */
		if (!(port->tty->termios->c_cflag & CLOCAL)){
			tty_hangup(port->tty);
		}
	}

	up (&port->sem);
	MOD_DEC_USE_COUNT;

} /* ftdi_sio_close */


  
/* The ftdi_sio requires the first byte to have:
 *  B0 1
 *  B1 0
 *  B2..7 length of message excluding byte 0
 */
static int ftdi_sio_write (struct usb_serial_port *port, int from_user, 
			   const unsigned char *buf, int count)
{ /* ftdi_sio_write */
	struct usb_serial *serial = port->serial;
	struct ftdi_private *priv = (struct ftdi_private *)port->private;
	unsigned char *first_byte = port->write_urb->transfer_buffer;
	int data_offset ;
	int result;
	
	dbg(__FUNCTION__ " port %d, %d bytes", port->number, count);

	if (count == 0) {
		err("write request of 0 bytes");
		return 0;
	}
	
	data_offset = priv->write_offset;
        dbg("data_offset set to %d",data_offset);

	if (port->write_urb->status == -EINPROGRESS) {
		dbg (__FUNCTION__ " - already writing");
		return (0);
	}		

	down(&port->sem);

	count += data_offset;
	count = (count > port->bulk_out_size) ? port->bulk_out_size : count;

		/* Copy in the data to send */
	if (from_user) {
		if (copy_from_user(port->write_urb->transfer_buffer + data_offset,
				   buf, count - data_offset )){
			up (&port->sem);
			return -EFAULT;
		}
	} else {
		memcpy(port->write_urb->transfer_buffer + data_offset,
		       buf, count - data_offset );
	}  

	first_byte = port->write_urb->transfer_buffer;
	if (data_offset > 0){
		/* Write the control byte at the front of the packet*/
		*first_byte = 1 | ((count-data_offset) << 2) ; 
	}

	dbg(__FUNCTION__ " Bytes: %d, First Byte: 0x%02x",count, first_byte[0]);
	usb_serial_debug_data (__FILE__, __FUNCTION__, count, first_byte);
		
	/* send the data out the bulk port */
	FILL_BULK_URB(port->write_urb, serial->dev, 
		      usb_sndbulkpipe(serial->dev, port->bulk_out_endpointAddress),
		      port->write_urb->transfer_buffer, count,
		      ftdi_sio_write_bulk_callback, port);
		
	result = usb_submit_urb(port->write_urb);
	if (result) {
		err(__FUNCTION__ " - failed submitting write urb, error %d", result);
		up (&port->sem);
		return 0;
	}
	up (&port->sem);

	dbg(__FUNCTION__ " write returning: %d", count - data_offset);
	return (count - data_offset);

} /* ftdi_sio_write */

static void ftdi_sio_write_bulk_callback (struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial;

	dbg("ftdi_sio_write_bulk_callback");

	if (port_paranoia_check (port, "ftdi_sio_write_bulk_callback")) {
		return;
	}
	
	serial = port->serial;
	if (serial_paranoia_check (serial, "ftdi_sio_write_bulk_callback")) {
		return;
	}
	
	if (urb->status) {
		dbg("nonzero write bulk status received: %d", urb->status);
		return;
	}
	queue_task(&port->tqueue, &tq_immediate);
	mark_bh(IMMEDIATE_BH);

	return;
} /* ftdi_sio_write_bulk_callback */


static int ftdi_sio_write_room( struct usb_serial_port *port )
{
	struct ftdi_private *priv = (struct ftdi_private *)port->private;
	int room;
	if ( port->write_urb->status == -EINPROGRESS) {
		/* There is a race here with the _write routines but it won't hurt */
		room = 0;
	} else { 
		room = port->bulk_out_size - priv->write_offset;
	}
	return(room);


} /* ftdi_sio_write_room */


static void ftdi_sio_read_bulk_callback (struct urb *urb)
{ /* ftdi_sio_serial_buld_callback */
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial;
       	struct tty_struct *tty = port->tty ;
	char error_flag;
       	unsigned char *data = urb->transfer_buffer;

	const int data_offset = 2;
	int i;
	int result;

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

	if (port_paranoia_check (port, "ftdi_sio_read_bulk_callback")) {
		return;
	}

	serial = port->serial;
	if (serial_paranoia_check (serial, "ftdi_sio_read_bulk_callback")) {
		return;
	}

	if (urb->status) {
		/* This will happen at close every time so it is a dbg not an err */
		dbg("nonzero read bulk status received: %d", urb->status);
		return;
	}

	if (urb->actual_length > 2) {
		usb_serial_debug_data (__FILE__, __FUNCTION__, urb->actual_length, data);
	} else {
                dbg("Just status 0o%03o0o%03o",data[0],data[1]);
        }


	/* TO DO -- check for hung up line and handle appropriately: */
	/*   send hangup  */
	/* See acm.c - you do a tty_hangup  - eg tty_hangup(tty) */
	/* if CD is dropped and the line is not CLOCAL then we should hangup */

	/* Handle errors and break */
	error_flag = TTY_NORMAL;
        /* Although the device uses a bitmask and hence can have multiple */
        /* errors on a packet - the order here sets the priority the */
        /* error is returned to the tty layer  */
	
	if ( data[1] & FTDI_RS_OE ) { 
		error_flag = TTY_OVERRUN;
                dbg("OVERRRUN error");
	}
	if ( data[1] & FTDI_RS_BI ) { 
		error_flag = TTY_BREAK;
                dbg("BREAK received");
	}
	if ( data[1] & FTDI_RS_PE ) { 
		error_flag = TTY_PARITY;
                dbg("PARITY error");
	}
	if ( data[1] & FTDI_RS_FE ) { 
		error_flag = TTY_FRAME;
                dbg("FRAMING error");
	}
	if (urb->actual_length > data_offset) {

		for (i = data_offset ; i < urb->actual_length ; ++i) {
			/* have to make sure we don't overflow the buffer
			  with tty_insert_flip_char's */
			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
				tty_flip_buffer_push(tty);
			}
			/* Note that the error flag is duplicated for 
			   every character received since we don't know
			   which character it applied to */
			tty_insert_flip_char(tty, data[i], error_flag);
		}
	  	tty_flip_buffer_push(tty);


	} 

#ifdef NOT_CORRECT_BUT_KEEPING_IT_FOR_NOW
	/* if a parity error is detected you get status packets forever
	   until a character is sent without a parity error.
	   This doesn't work well since the application receives a never
	   ending stream of bad data - even though new data hasn't been sent.
	   Therefore I (bill) have taken this out.
	   However - this might make sense for framing errors and so on 
	   so I am leaving the code in for now.
	*/
      else {
		if (error_flag != TTY_NORMAL){
			dbg("error_flag is not normal");
				/* In this case it is just status - if that is an error send a bad character */
				if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
					tty_flip_buffer_push(tty);
				}
				tty_insert_flip_char(tty, 0xff, error_flag);
				tty_flip_buffer_push(tty);
		}
	}
#endif

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

	result = usb_submit_urb(port->read_urb);
	if (result)
		err(__FUNCTION__ " - failed resubmitting read urb, error %d", result);

	return;
} /* ftdi_sio_serial_read_bulk_callback */


static __u16 translate_baudrate_to_ftdi(unsigned int cflag, ftdi_type_t ftdi_type) 
{ /* translate_baudrate_to_ftdi */
	
	__u16 urb_value = ftdi_sio_b9600;

	if (ftdi_type == sio){
		switch(cflag & CBAUD){
		case B0: break; /* ignored by this */
		case B300: urb_value = ftdi_sio_b300; dbg("Set to 300"); break;
		case B600: urb_value = ftdi_sio_b600; dbg("Set to 600") ; break;
		case B1200: urb_value = ftdi_sio_b1200; dbg("Set to 1200") ; break;
		case B2400: urb_value = ftdi_sio_b2400; dbg("Set to 2400") ; break;
		case B4800: urb_value = ftdi_sio_b4800; dbg("Set to 4800") ; break;
		case B9600: urb_value = ftdi_sio_b9600; dbg("Set to 9600") ; break;