mfd: Introduce lpc_sch for Intel SCH LPC bridge

Intel Poulsbo (SCH) chipset LPC bridge controller contains several
functions. Creating and MFD driver for the LPC bridge controller allows
simultaneous use of SMBus and GPIO interfaces on the SCH.

Signed-off-by: Denis Turischev <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/Kconfig

···
 
 	The timberdale FPGA can be found on the Intel Atom development board
 	for in-vehicle infontainment, called Russellville.
+
+config LPC_SCH
+	tristate "Intel SCH LPC"
+	depends on PCI
+	select MFD_CORE
+	help
+	  LPC bridge function of the Intel SCH provides support for
+	  System Management Bus and General Purpose I/O.
+
 endmenu
 
 menu "Multimedia Capabilities Port drivers"

drivers/mfd/Makefile

···
 obj-$(CONFIG_AB4500_CORE)	+= ab4500-core.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)	+= adp5520.o
+obj-$(CONFIG_LPC_SCH)		+= lpc_sch.o

drivers/mfd/lpc_sch.c

···
+/*
+ *  lpc_sch.c - LPC interface for Intel Poulsbo SCH
+ *
+ *  LPC bridge function of the Intel SCH contains many other
+ *  functional units, such as Interrupt controllers, Timers,
+ *  Power Management, System Management, GPIO, RTC, and LPC
+ *  Configuration Registers.
+ *
+ *  Copyright (c) 2010 CompuLab Ltd
+ *  Author: Denis Turischev <[e-mail]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 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; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include <linux/mfd/core.h>
+
+#define SMBASE		0x40
+#define SMBUS_IO_SIZE	64
+
+#define GPIOBASE	0x44
+#define GPIO_IO_SIZE	64
+
+static struct resource smbus_sch_resource = {
+		.flags = IORESOURCE_IO,
+};
+
+
+static struct resource gpio_sch_resource = {
+		.flags = IORESOURCE_IO,
+};
+
+static struct mfd_cell lpc_sch_cells[] = {
+	{
+		.name = "isch_smbus",
+		.num_resources = 1,
+		.resources = &smbus_sch_resource,
+	},
+	{
+		.name = "sch_gpio",
+		.num_resources = 1,
+		.resources = &gpio_sch_resource,
+	},
+};
+
+static struct pci_device_id lpc_sch_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC) },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, lpc_sch_ids);
+
+static int __devinit lpc_sch_probe(struct pci_dev *dev,
+				const struct pci_device_id *id)
+{
+	unsigned int base_addr_cfg;
+	unsigned short base_addr;
+
+	pci_read_config_dword(dev, SMBASE, &base_addr_cfg);
+	if (!(base_addr_cfg & (1 << 31))) {
+		dev_err(&dev->dev, "Decode of the SMBus I/O range disabled\n");
+		return -ENODEV;
+	}
+	base_addr = (unsigned short)base_addr_cfg;
+	if (base_addr == 0) {
+		dev_err(&dev->dev, "I/O space for SMBus uninitialized\n");
+		return -ENODEV;
+	}
+
+	smbus_sch_resource.start = base_addr;
+	smbus_sch_resource.end = base_addr + SMBUS_IO_SIZE - 1;
+
+	pci_read_config_dword(dev, GPIOBASE, &base_addr_cfg);
+	if (!(base_addr_cfg & (1 << 31))) {
+		dev_err(&dev->dev, "Decode of the GPIO I/O range disabled\n");
+		return -ENODEV;
+	}
+	base_addr = (unsigned short)base_addr_cfg;
+	if (base_addr == 0) {
+		dev_err(&dev->dev, "I/O space for GPIO uninitialized\n");
+		return -ENODEV;
+	}
+
+	gpio_sch_resource.start = base_addr;
+	gpio_sch_resource.end = base_addr + GPIO_IO_SIZE - 1;
+
+	return mfd_add_devices(&dev->dev, -1,
+			lpc_sch_cells, ARRAY_SIZE(lpc_sch_cells), NULL, 0);
+}
+
+static void __devexit lpc_sch_remove(struct pci_dev *dev)
+{
+	mfd_remove_devices(&dev->dev);
+}
+
+static struct pci_driver lpc_sch_driver = {
+	.name		= "lpc_sch",
+	.id_table	= lpc_sch_ids,
+	.probe		= lpc_sch_probe,
+	.remove		= __devexit_p(lpc_sch_remove),
+};
+
+static int __init lpc_sch_init(void)
+{
+	return pci_register_driver(&lpc_sch_driver);
+}
+
+static void __exit lpc_sch_exit(void)
+{
+	pci_unregister_driver(&lpc_sch_driver);
+}
+
+module_init(lpc_sch_init);
+module_exit(lpc_sch_exit);
+
+MODULE_AUTHOR("Denis Turischev <[e-mail]>");
+MODULE_DESCRIPTION("LPC interface for Intel Poulsbo SCH");
+MODULE_LICENSE("GPL");