tty: Bring the usb tty port structure into more use

This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/usb/serial/spcp8x5.c

@@ -446,66 +446,47 @@ static void spcp8x5_set_workMode(struct usb_device *dev, u16 value,
 			"RTSCTS usb_control_msg(enable flowctrl) = %d\n", ret);
 }
 
-/* close the serial port. We should wait for data sending to device 1st and
- * then kill all urb. */
-static void spcp8x5_close(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp)
+static int spcp8x5_carrier_raised(struct usb_serial_port *port)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	if (priv->line_status & MSR_STATUS_LINE_DCD)
+		return 1;
+	return 0;
+}
+
+static void spcp8x5_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	u8 control;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (on)
+		priv->line_control = MCR_CONTROL_LINE_DTR
+						| MCR_CONTROL_LINE_RTS;
+	else
+		priv->line_control &= ~ (MCR_CONTROL_LINE_DTR
+						| MCR_CONTROL_LINE_RTS);
+	control = priv->line_control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+	spcp8x5_set_ctrlLine(port->serial->dev, control , priv->type);
+}
+
+/* close the serial port. We should wait for data sending to device 1st and
+ * then kill all urb. */
+static void spcp8x5_close(struct usb_serial_port *port)
 {
 	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
 	unsigned long flags;
-	unsigned int c_cflag;
-	int bps;
-	long timeout;
-	wait_queue_t wait;
 	int result;
 
 	dbg("%s - port %d", __func__, port->number);
 
-	/* wait for data to drain from the buffer */
 	spin_lock_irqsave(&priv->lock, flags);
-	timeout = SPCP8x5_CLOSING_WAIT;
-	init_waitqueue_entry(&wait, current);
-	add_wait_queue(&tty->write_wait, &wait);
-	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (ringbuf_avail_data(priv->buf) == 0 ||
-		    timeout == 0 || signal_pending(current))
-			break;
-		spin_unlock_irqrestore(&priv->lock, flags);
-		timeout = schedule_timeout(timeout);
-		spin_lock_irqsave(&priv->lock, flags);
-	}
-	set_current_state(TASK_RUNNING);
-	remove_wait_queue(&tty->write_wait, &wait);
-
 	/* clear out any remaining data in the buffer */
 	clear_ringbuf(priv->buf);
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	/* wait for characters to drain from the device (this is long enough
-	 * for the entire all byte spcp8x5 hardware buffer to drain with no
-	 * flow control for data rates of 1200 bps or more, for lower rates we
-	 * should really know how much data is in the buffer to compute a delay
-	 * that is not unnecessarily long) */
-	bps = tty_get_baud_rate(tty);
-	if (bps > 1200)
-		timeout = max((HZ*2560) / bps, HZ/10);
-	else
-		timeout = 2*HZ;
-	set_current_state(TASK_INTERRUPTIBLE);
-	schedule_timeout(timeout);
-
-	/* clear control lines */
-	if (tty) {
-		c_cflag = tty->termios->c_cflag;
-		if (c_cflag & HUPCL) {
-			spin_lock_irqsave(&priv->lock, flags);
-			priv->line_control = 0;
-			spin_unlock_irqrestore(&priv->lock, flags);
-			spcp8x5_set_ctrlLine(port->serial->dev, 0 , priv->type);
-		}
-	}
-
 	/* kill urb */
 	if (port->write_urb != NULL) {
 		result = usb_unlink_urb(port->write_urb);
@@ -665,13 +646,6 @@ static int spcp8x5_open(struct tty_struct *tty,
 	if (ret)
 		return ret;
 
-	spin_lock_irqsave(&priv->lock, flags);
-	if (tty && (tty->termios->c_cflag & CBAUD))
-		priv->line_control = MCR_DTR | MCR_RTS;
-	else
-		priv->line_control = 0;
-	spin_unlock_irqrestore(&priv->lock, flags);
-
 	spcp8x5_set_ctrlLine(serial->dev, priv->line_control , priv->type);
 
 	/* Setup termios */
@@ -691,9 +665,10 @@ static int spcp8x5_open(struct tty_struct *tty,
 	port->read_urb->dev = serial->dev;
 	ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
 	if (ret) {
-		spcp8x5_close(tty, port, NULL);
+		spcp8x5_close(port);
 		return -EPROTO;
 	}
+	port->port.drain_delay = 256;
 	return 0;
 }
 
@@ -1033,6 +1008,8 @@ static struct usb_serial_driver spcp8x5_device = {
 	.num_ports		= 1,
 	.open 			= spcp8x5_open,
 	.close 			= spcp8x5_close,
+	.dtr_rts		= spcp8x5_dtr_rts,
+	.carrier_raised		= spcp8x5_carrier_raised,
 	.write 			= spcp8x5_write,
 	.set_termios 		= spcp8x5_set_termios,
 	.ioctl 			= spcp8x5_ioctl,