serial: 8250_pci: Add MKS Tenta SCOM-0800 and SCOM-0801 cards

The MKS Instruments SCOM-0800 and SCOM-0801 cards (originally by Tenta
Technologies) are 3U CompactPCI serial cards with 4 and 8 serial ports,
respectively.  The first 4 ports are implemented by an OX16PCI954 chip,
and the second 4 ports are implemented by an OX16C954 chip on a local
bus, bridged by the second PCI function of the OX16PCI954.  The ports
are jumper-selectable as RS-232 and RS-422/485, and the UARTs use a
non-standard oscillator frequency of 20 MHz (base_baud = 1250000).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_pci.c

@@ -2577,6 +2577,8 @@ enum pci_board_num_t {
 	pbn_b0_4_1152000_200,
 	pbn_b0_8_1152000_200,
 
+	pbn_b0_4_1250000,
+
 	pbn_b0_2_1843200,
 	pbn_b0_4_1843200,
 
@@ -2799,6 +2801,13 @@ static struct pciserial_board pci_boards[] = {
 		.uart_offset	= 0x200,
 	},
 
+	[pbn_b0_4_1250000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 1250000,
+		.uart_offset	= 8,
+	},
+
 	[pbn_b0_2_1843200] = {
 		.flags		= FL_BASE0,
 		.num_ports	= 2,
@@ -5264,6 +5273,10 @@ static struct pci_device_id serial_pci_tbl[] = {
 	{ PCI_DEVICE(0x1c29, 0x1108), .driver_data = pbn_fintek_8 },
 	{ PCI_DEVICE(0x1c29, 0x1112), .driver_data = pbn_fintek_12 },
 
+	/* MKS Tenta SCOM-080x serial cards */
+	{ PCI_DEVICE(0x1601, 0x0800), .driver_data = pbn_b0_4_1250000 },
+	{ PCI_DEVICE(0x1601, 0xa801), .driver_data = pbn_b0_4_1250000 },
+
 	/*
 	 * These entries match devices with class COMMUNICATION_SERIAL,
 	 * COMMUNICATION_MODEM or COMMUNICATION_MULTISERIAL