ftdi_sio.c

linux2.4.20下的针对三星公司的s3c2410的usb模块驱动代码

	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
		return -EFAULT;
	return 0;
} /* get_serial_info */


static int set_serial_info(struct usb_serial_port * port, struct serial_struct * newinfo)
{ /* set_serial_info */
	struct ftdi_private * priv = (struct ftdi_private *) port->private;
	struct serial_struct new_serial;
	struct ftdi_private old_priv;

	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
		return -EFAULT;
	old_priv = * priv;

	/* Do error checking and permission checking */

	if (!capable(CAP_SYS_ADMIN)) {
		if (((new_serial.flags & ~ASYNC_USR_MASK) !=
		     (priv->flags & ~ASYNC_USR_MASK)))
			return -EPERM;
		priv->flags = ((priv->flags & ~ASYNC_USR_MASK) |
			       (new_serial.flags & ASYNC_USR_MASK));
		priv->custom_divisor = new_serial.custom_divisor;
		goto check_and_exit;
	}

	if ((new_serial.baud_base != priv->baud_base) ||
	    (new_serial.baud_base < 9600))
		return -EINVAL;

	/* Make the changes - these are privileged changes! */

	priv->flags = ((priv->flags & ~ASYNC_FLAGS) |
	               (new_serial.flags & ASYNC_FLAGS));	
	priv->custom_divisor = new_serial.custom_divisor;

	port->tty->low_latency = (priv->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

check_and_exit:
	if (((old_priv.flags & ASYNC_SPD_MASK) !=
	     (priv->flags & ASYNC_SPD_MASK)) ||
	    (old_priv.custom_divisor != priv->custom_divisor)) {
		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
			port->tty->alt_speed = 57600;
		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
			port->tty->alt_speed = 115200;
		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
			port->tty->alt_speed = 230400;
		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
			port->tty->alt_speed = 460800;
		change_speed(port);
	}
	
	return (0);

} /* set_serial_info */

/*
 * ***************************************************************************
 * FTDI driver specific functions
 * ***************************************************************************
 */

/* Startup for the SIO chip */
static int ftdi_SIO_startup (struct usb_serial *serial)
{
	struct ftdi_private *priv;

	priv = serial->port->private = kmalloc(sizeof(struct ftdi_private), GFP_KERNEL);
	if (!priv){
		err("%s- kmalloc(%Zd) failed.", __FUNCTION__, sizeof(struct ftdi_private));
		return -ENOMEM;
	}

	priv->chip_type = SIO;
	priv->baud_base = 12000000 / 16;
	priv->custom_divisor = 0;
	priv->write_offset = 1;
 	priv->prev_status = priv->diff_status = 0;
	/* This will push the characters through immediately rather
	   than queue a task to deliver them */
	priv->flags = ASYNC_LOW_LATENCY;
	
	return (0);
}

/* Startup for the 8U232AM chip */
static int ftdi_8U232AM_startup (struct usb_serial *serial)
{
	struct ftdi_private *priv;

	priv = serial->port->private = kmalloc(sizeof(struct ftdi_private), GFP_KERNEL);
	if (!priv){
		err("%s- kmalloc(%Zd) failed.", __FUNCTION__, sizeof(struct ftdi_private));
		return -ENOMEM;
	}

	priv->chip_type = FT8U232AM;
	priv->baud_base = 48000000 / 2; /* Would be / 16, but FTDI supports 0.125, 0.25 and 0.5 divisor fractions! */
	priv->custom_divisor = 0;
	priv->write_offset = 0;
        init_waitqueue_head(&priv->delta_msr_wait);
	/* This will push the characters through immediately rather
	   than queue a task to deliver them */
	priv->flags = ASYNC_LOW_LATENCY;
	
	return (0);
}


static void ftdi_shutdown (struct usb_serial *serial)
{
	dbg("%s", __FUNCTION__);

	/* stop reads and writes on all ports */
	while (serial->port[0].open_count > 0) {
	        ftdi_close (&serial->port[0], NULL);
	}
	if (serial->port[0].private){
		kfree(serial->port[0].private);
		serial->port[0].private = NULL;
	}
}


static int  ftdi_open (struct usb_serial_port *port, struct file *filp)
{ /* ftdi_open */
	struct termios tmp_termios;
	struct usb_serial *serial = port->serial;
	struct ftdi_private *priv = port->private;
	
	int result = 0;
	char buf[1]; /* Needed for the usb_control_msg I think */

	dbg("%s", __FUNCTION__);


	port->tty->low_latency = (priv->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	/* No error checking for this (will get errors later anyway) */
	/* See ftdi_sio.h for description of what is reset */
	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);

	/* Termios defaults are set by usb_serial_init. We don't change
	   port->tty->termios - this would loose speed settings, etc.
	   This is same behaviour as serial.c/rs_open() - Kuba */

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

	/* FIXME: Flow control might be enabled, so it should be checked -
	   we have no control of defaults! */
	/* 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("%s Error from DTR HIGH urb", __FUNCTION__);
	}
	if (set_rts(serial->dev, usb_sndctrlpipe(serial->dev, 0),HIGH) < 0){
		err("%s Error from RTS HIGH urb", __FUNCTION__);
	}

	/* 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_read_bulk_callback, port);
	result = usb_submit_urb(port->read_urb);
	if (result)
		err("%s - failed submitting read urb, error %d", __FUNCTION__, result);

	return result;
} /* ftdi_open */


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

	dbg("%s", __FUNCTION__);

	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);
	}
} /* ftdi_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_write (struct usb_serial_port *port, int from_user,
			   const unsigned char *buf, int count)
{ /* ftdi_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("%s port %d, %d bytes", __FUNCTION__, 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("%s - already writing", __FUNCTION__);
		return (0);
	}		

	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 )){
			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("%s Bytes: %d, First Byte: 0x%02x", __FUNCTION__,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_write_bulk_callback, port);
		
	result = usb_submit_urb(port->write_urb);
	if (result) {
		err("%s - failed submitting write urb, error %d", __FUNCTION__, result);
		return 0;
	}

	dbg("%s write returning: %d", __FUNCTION__, count - data_offset);
	return (count - data_offset);
} /* ftdi_write */


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

	dbg("%s", __FUNCTION__);

	if (port_paranoia_check (port, "ftdi_write_bulk_callback")) {
		return;
	}
	
	serial = port->serial;
	if (serial_paranoia_check (serial, "ftdi_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_write_bulk_callback */


static int ftdi_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_write_room */


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

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

	dbg("%s - port %d", __FUNCTION__, 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 */

	/* Compare new line status to the old one, signal if different */
	if (priv != NULL) {
		char new_status = data[0] & FTDI_STATUS_B0_MASK;
		if (new_status != priv->prev_status) {
			priv->diff_status |= new_status ^ priv->prev_status;
			wake_up_interruptible(&priv->delta_msr_wait);
			priv->prev_status = new_status;
		}
	}

	/* 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) {