tty: serial: 8250: Add SystemBase Multi I/O cards

Add support for the SystemBase Multi I/O serial cards, which are
"compatible" with a standard 16550A controllers, except that they need
to have their interrupts enabled in a proprietary way.

Tested with a Delock "Serial PCI Express x1 Card 8x Serial RS-232".

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://patch.msgid.link/20260225081739.946723-1-mwalle@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: mwalle

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

@@ -100,6 +100,8 @@
 #define PCI_DEVICE_ID_ADDIDATA_CPCI7420_NG     0x7025
 #define PCI_DEVICE_ID_ADDIDATA_CPCI7300_NG     0x7026
 
+#define PCI_VENDOR_ID_SYSTEMBASE	0x14a1
+
 /* Unknown vendors/cards - this should not be in linux/pci_ids.h */
 #define PCI_SUBDEVICE_ID_UNKNOWN_0x1584	0x1584
 #define PCI_SUBDEVICE_ID_UNKNOWN_0x1588	0x1588
@@ -2128,6 +2130,35 @@ pci_moxa_setup(struct serial_private *priv,
 	return setup_port(priv, port, bar, offset, 0);
 }
 
+#define SB_OPTR_IMR0	0x0c /* Interrupt mask register, p0 to p7 */
+static int pci_systembase_init(struct pci_dev *dev)
+{
+	resource_size_t iobase;
+
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
+
+	iobase = pci_resource_start(dev, 1);
+
+	/* This will support up to 8 ports */
+	outb(0xff, iobase + SB_OPTR_IMR0);
+
+	return 0;
+}
+
+static void pci_systembase_exit(struct pci_dev *dev)
+{
+	resource_size_t iobase;
+
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT)) {
+		serial_8250_warn_need_ioport(dev);
+		return;
+	}
+
+	iobase = pci_resource_start(dev, 0);
+	outb(0x00, iobase + SB_OPTR_IMR0);
+}
+
 /*
  * Master list of serial port init/setup/exit quirks.
  * This does not describe the general nature of the port.
@@ -2476,6 +2507,16 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 		.init		= pci_siig_init,
 		.setup		= pci_siig_setup,
 	},
+	/* Systembase */
+	{
+		.vendor		= PCI_VENDOR_ID_SYSTEMBASE,
+		.device		= 0x0008,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_systembase_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_systembase_exit,
+	},
 	/*
 	 * Titan cards
 	 */
@@ -3041,6 +3082,7 @@ enum pci_board_num_t {
 	pbn_b0_1_921600,
 	pbn_b0_2_921600,
 	pbn_b0_4_921600,
+	pbn_b0_8_921600,
 
 	pbn_b0_2_1130000,
 
@@ -3241,6 +3283,12 @@ static struct pciserial_board pci_boards[] = {
 		.base_baud	= 921600,
 		.uart_offset	= 8,
 	},
+	[pbn_b0_8_921600] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
 
 	[pbn_b0_2_1130000] = {
 		.flags          = FL_BASE0,
@@ -6152,6 +6200,9 @@ static const struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID,
 		0, 0, pbn_b0_1_115200 },
 
+	/* Systembase Multi I/O cards */
+	{ PCI_VDEVICE(SYSTEMBASE, 0x0008), pbn_b0_8_921600 },
+
 	/* Fintek PCI serial cards */
 	{ PCI_DEVICE(0x1c29, 0x1104), .driver_data = pbn_fintek_4 },
 	{ PCI_DEVICE(0x1c29, 0x1108), .driver_data = pbn_fintek_8 },