1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
new file mode 100644
index 000000000000..9d5d2531a33b
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pcilib.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250 PCI library.
+ *
+ * Copyright (C) 2001 Russell King, All Rights Reserved.
+ */
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+
+#include "8250.h"
+#include "8250_pcilib.h"
+
+int serial_8250_warn_need_ioport(struct pci_dev *dev)
+{
+	dev_warn(&dev->dev,
+		 "Serial port not supported because of missing I/O resource\n");
+
+	return -ENXIO;
+}
+EXPORT_SYMBOL_NS_GPL(serial_8250_warn_need_ioport, "SERIAL_8250_PCI");
+
+int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
+		   u8 bar, unsigned int offset, int regshift, void __iomem *iomem)
+{
+	if (bar >= PCI_STD_NUM_BARS)
+		return -EINVAL;
+
+	if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
+		port->port.iotype = UPIO_MEM;
+		port->port.iobase = 0;
+		port->port.mapbase = pci_resource_start(dev, bar) + offset;
+		port->port.membase = iomem + offset;
+		port->port.regshift = regshift;
+	} else if (IS_ENABLED(CONFIG_HAS_IOPORT)) {
+		port->port.iotype = UPIO_PORT;
+		port->port.iobase = pci_resource_start(dev, bar) + offset;
+		port->port.mapbase = 0;
+		port->port.membase = NULL;
+		port->port.regshift = 0;
+	} else {
+		return serial_8250_warn_need_ioport(dev);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(serial8250_pci_setup_port, "SERIAL_8250_PCI");
+MODULE_DESCRIPTION("8250 PCI library");
+MODULE_LICENSE("GPL");