serial: Support the EFR-register of XR1715x uarts.

The EFR (Enhenced-Features-Register) is located at a different offset
than the other devices supporting UART_CAP_EFR. This change add a special
setup quick to set UPF_EXAR_EFR on the port. UPF_EXAR_EFR is then used to
the port type to PORT_XR17D15X since it is for sure a XR17D15X uart.

Signed-off-by: Søren Holm <sgh@sgh.dk>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c
index 6b887d9..a79caba 100644
--- a/drivers/tty/serial/8250_pci.c
+++ b/drivers/tty/serial/8250_pci.c
@@ -1101,6 +1101,15 @@
 #endif
 }
 
+static int
+pci_xr17c154_setup(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_port *port, int idx)
+{
+	port->flags |= UPF_EXAR_EFR;
+	return pci_default_setup(priv, board, port, idx);
+}
+
 /* This should be in linux/pci_ids.h */
 #define PCI_VENDOR_ID_SBSMODULARIO	0x124B
 #define PCI_SUBVENDOR_ID_SBSMODULARIO	0x124B
@@ -1506,6 +1515,30 @@
 		.setup		= pci_timedia_setup,
 	},
 	/*
+	 * Exar cards
+	 */
+	{
+		.vendor = PCI_VENDOR_ID_EXAR,
+		.device = PCI_DEVICE_ID_EXAR_XR17C152,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_xr17c154_setup,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_EXAR,
+		.device = PCI_DEVICE_ID_EXAR_XR17C154,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_xr17c154_setup,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_EXAR,
+		.device = PCI_DEVICE_ID_EXAR_XR17C158,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_xr17c154_setup,
+	},
+	/*
 	 * Xircom cards
 	 */
 	{