ipack/devices/ipoctal: added shutdown callback

Added shutdown callback to disable RX and TX when there is no other client
accesing the device.
Signed-off-by: NSamuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/ipack/devices/ipoctal.c

@@ -625,6 +625,22 @@ static void ipoctal_hangup(struct tty_struct *tty)
 	wake_up_interruptible(&channel->tty_port.open_wait);
 }
 
+static void ipoctal_shutdown(struct tty_struct *tty)
+{
+	struct ipoctal_channel *channel = tty->driver_data;
+
+	if (channel == NULL)
+		return;
+
+	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
+	channel->rx_enable = 0;
+	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
+	clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
+}
+
 static const struct tty_operations ipoctal_fops = {
 	.ioctl =		NULL,
 	.open =			ipoctal_open,
@@ -635,6 +651,7 @@ static const struct tty_operations ipoctal_fops = {
 	.chars_in_buffer =	ipoctal_chars_in_buffer,
 	.get_icount =		ipoctal_get_icount,
 	.hangup =		ipoctal_hangup,
+	.shutdown =		ipoctal_shutdown,
 };
 
 static int ipoctal_probe(struct ipack_device *dev)