diff --git a/drivers/mfd/cs5535-mfd.c b/drivers/mfd/cs5535-mfd.c
new file mode 100644
index 0000000..b141ca7
--- /dev/null
+++ b/drivers/mfd/cs5535-mfd.c
@@ -0,0 +1,151 @@
+/*
+ * cs5535-mfd.c - core MFD driver for CS5535/CS5536 southbridges
+ *
+ * The CS5535 and CS5536 has an ISA bridge on the PCI bus that is
+ * used for accessing GPIOs, MFGPTs, ACPI, etc.  Each subdevice has
+ * an IO range that's specified in a single BAR.  The BAR order is
+ * hardcoded in the CS553x specifications.
+ *
+ * Copyright (c) 2010  Andres Salomon <dilinger@queued.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#define DRV_NAME "cs5535-mfd"
+
+enum cs5535_mfd_bars {
+	SMB_BAR = 0,
+	GPIO_BAR = 1,
+	MFGPT_BAR = 2,
+	PMS_BAR = 4,
+	ACPI_BAR = 5,
+	NR_BARS,
+};
+
+static __devinitdata struct resource cs5535_mfd_resources[NR_BARS];
+
+static __devinitdata struct mfd_cell cs5535_mfd_cells[] = {
+	{
+		.id = SMB_BAR,
+		.name = "cs5535-smb",
+		.num_resources = 1,
+		.resources = &cs5535_mfd_resources[SMB_BAR],
+	},
+	{
+		.id = GPIO_BAR,
+		.name = "cs5535-gpio",
+		.num_resources = 1,
+		.resources = &cs5535_mfd_resources[GPIO_BAR],
+	},
+	{
+		.id = MFGPT_BAR,
+		.name = "cs5535-mfgpt",
+		.num_resources = 1,
+		.resources = &cs5535_mfd_resources[MFGPT_BAR],
+	},
+	{
+		.id = PMS_BAR,
+		.name = "cs5535-pms",
+		.num_resources = 1,
+		.resources = &cs5535_mfd_resources[PMS_BAR],
+	},
+	{
+		.id = ACPI_BAR,
+		.name = "cs5535-acpi",
+		.num_resources = 1,
+		.resources = &cs5535_mfd_resources[ACPI_BAR],
+	},
+};
+
+static int __devinit cs5535_mfd_probe(struct pci_dev *pdev,
+		const struct pci_device_id *id)
+{
+	int err, i;
+
+	err = pci_enable_device(pdev);
+	if (err)
+		return err;
+
+	/* fill in IO range for each cell; subdrivers handle the region */
+	for (i = 0; i < ARRAY_SIZE(cs5535_mfd_cells); i++) {
+		int bar = cs5535_mfd_cells[i].id;
+		struct resource *r = &cs5535_mfd_resources[bar];
+
+		r->flags = IORESOURCE_IO;
+		r->start = pci_resource_start(pdev, bar);
+		r->end = pci_resource_end(pdev, bar);
+
+		/* id is used for temporarily storing BAR; unset it now */
+		cs5535_mfd_cells[i].id = 0;
+	}
+
+	err = mfd_add_devices(&pdev->dev, -1, cs5535_mfd_cells,
+			ARRAY_SIZE(cs5535_mfd_cells), NULL, 0);
+	if (err) {
+		dev_err(&pdev->dev, "MFD add devices failed: %d\n", err);
+		goto err_disable;
+	}
+
+	dev_info(&pdev->dev, "%d devices registered.\n",
+			ARRAY_SIZE(cs5535_mfd_cells));
+
+	return 0;
+
+err_disable:
+	pci_disable_device(pdev);
+	return err;
+}
+
+static void __devexit cs5535_mfd_remove(struct pci_dev *pdev)
+{
+	mfd_remove_devices(&pdev->dev);
+	pci_disable_device(pdev);
+}
+
+static struct pci_device_id cs5535_mfd_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, cs5535_mfd_pci_tbl);
+
+static struct pci_driver cs5535_mfd_drv = {
+	.name = DRV_NAME,
+	.id_table = cs5535_mfd_pci_tbl,
+	.probe = cs5535_mfd_probe,
+	.remove = __devexit_p(cs5535_mfd_remove),
+};
+
+static int __init cs5535_mfd_init(void)
+{
+	return pci_register_driver(&cs5535_mfd_drv);
+}
+
+static void __exit cs5535_mfd_exit(void)
+{
+	pci_unregister_driver(&cs5535_mfd_drv);
+}
+
+module_init(cs5535_mfd_init);
+module_exit(cs5535_mfd_exit);
+
+MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
+MODULE_DESCRIPTION("MFD driver for CS5535/CS5536 southbridge's ISA PCI device");
+MODULE_LICENSE("GPL");