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>
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index bf1ae24..ab769db 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -651,6 +651,35 @@
 }
 
 
+static void keyspan_pda_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct usb_serial *serial = port->serial;
+
+	if (serial->dev) {
+		if (on)
+			keyspan_pda_set_modem_info(serial, (1<<7) | (1<< 2));
+		else
+			keyspan_pda_set_modem_info(serial, 0);
+	}
+}
+
+static int keyspan_pda_carrier_raised(struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	unsigned char modembits;
+
+	/* If we can read the modem status and the DCD is low then
+	   carrier is not raised yet */
+	if (keyspan_pda_get_modem_info(serial, &modembits) >= 0) {
+		if (!(modembits & (1>>6)))
+			return 0;
+	}
+	/* Carrier raised, or we failed (eg disconnected) so
+	   progress accordingly */
+	return 1;
+}
+
+
 static int keyspan_pda_open(struct tty_struct *tty,
 			struct usb_serial_port *port, struct file *filp)
 {
@@ -682,13 +711,6 @@
 	priv->tx_room = room;
 	priv->tx_throttled = room ? 0 : 1;
 
-	/* the normal serial device seems to always turn on DTR and RTS here,
-	   so do the same */
-	if (tty && (tty->termios->c_cflag & CBAUD))
-		keyspan_pda_set_modem_info(serial, (1<<7) | (1<<2));
-	else
-		keyspan_pda_set_modem_info(serial, 0);
-
 	/*Start reading from the device*/
 	port->interrupt_in_urb->dev = serial->dev;
 	rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
@@ -700,19 +722,11 @@
 error:
 	return rc;
 }
-
-
-static void keyspan_pda_close(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp)
+static void keyspan_pda_close(struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
 
 	if (serial->dev) {
-		/* the normal serial device seems to always shut
-		   off DTR and RTS now */
-		if (tty->termios->c_cflag & HUPCL)
-			keyspan_pda_set_modem_info(serial, 0);
-
 		/* shutdown our bulk reads and writes */
 		usb_kill_urb(port->write_urb);
 		usb_kill_urb(port->interrupt_in_urb);
@@ -839,6 +853,8 @@
 	.usb_driver = 		&keyspan_pda_driver,
 	.id_table =		id_table_std,
 	.num_ports =		1,
+	.dtr_rts =		keyspan_pda_dtr_rts,
+	.carrier_raised	=	keyspan_pda_carrier_raised,
 	.open =			keyspan_pda_open,
 	.close =		keyspan_pda_close,
 	.write =		keyspan_pda_write,