[4/5] USB: serial: f81232: implement break control

["Ji-Ze Hong \(Peter Hong\)" <hpeter@gmail.com>]

Implement Fintek F81232 break on/off with LCR register.
It's the same with 16550A LCR register layout.

Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index dadf024ae494..a054f69446fd 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -377,13 +377,18 @@ static void f81232_process_read_urb(struct urb *urb)
 
 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 {
-	/* FIXME - Stubbed out for now */
+	struct usb_serial_port *port = tty->driver_data;
+	struct f81232_private *priv = usb_get_serial_port_data(port);
+	int status;
 
-	/*
-	 * break_state = -1 to turn on break, and 0 to turn off break
-	 * see drivers/char/tty_io.c to see it used.
-	 * last_set_data_urb_value NEVER has the break bit set in it.
-	 */
+	mutex_lock(&priv->lock);
+
+	status = f81232_set_mask_register(port, LINE_CONTROL_REGISTER,
+						UART_LCR_SBC, !!break_state);
+	if (status)
+		dev_err(&port->dev, "set break failed: %d\n", status);
+
+	mutex_unlock(&priv->lock);
 }
 
 static int f81232_find_clk(speed_t baudrate)