drivers/gpio/langwell_gpio.c - kernel/msm-4.9 - Gitiles

 /* langwell_gpio.c Moorestown platform Langwell chip GPIO driver
  * Copyright (c) 2008 - 2009,  Intel Corporation.
  *
  * 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.
  */

 /* Supports:
  * Moorestown platform Langwell chip.
  * Medfield platform Penwell chip.
  * Whitney point.
  */

 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/stddef.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>

 /*
  * Langwell chip has 64 pins and thus there are 2 32bit registers to control
  * each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
  * registers to control them, so we only define the order here instead of a
  * structure, to get a bit offset for a pin (use GPDR as an example):
  *
  * nreg = ngpio / 32;
  * reg = offset / 32;
  * bit = offset % 32;
  * reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
  *
  * so the bit of reg_addr is to control pin offset's GPDR feature
 */

 enum GPIO_REG {
 	GPLR = 0,	/* pin level read-only */
 	GPDR,		/* pin direction */
 	GPSR,		/* pin set */
 	GPCR,		/* pin clear */
 	GRER,		/* rising edge detect */
 	GFER,		/* falling edge detect */
 	GEDR,		/* edge detect result */
 };

 struct lnw_gpio {
 	struct gpio_chip		chip;
 	void				*reg_base;
 	spinlock_t			lock;
 	unsigned			irq_base;
 };

 static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
 			enum GPIO_REG reg_type)
 {
 	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
 	unsigned nreg = chip->ngpio / 32;
 	u8 reg = offset / 32;
 	void __iomem *ptr;

 	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
 	return ptr;
 }

 static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	void __iomem *gplr = gpio_reg(chip, offset, GPLR);

 	return readl(gplr) & BIT(offset % 32);
 }

 static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 {
 	void __iomem *gpsr, *gpcr;

 	if (value) {
 		gpsr = gpio_reg(chip, offset, GPSR);
 		writel(BIT(offset % 32), gpsr);
 	} else {
 		gpcr = gpio_reg(chip, offset, GPCR);
 		writel(BIT(offset % 32), gpcr);
 	}
 }

 static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 {
 	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
 	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
 	u32 value;
 	unsigned long flags;

 	spin_lock_irqsave(&lnw->lock, flags);
 	value = readl(gpdr);
 	value &= ~BIT(offset % 32);
 	writel(value, gpdr);
 	spin_unlock_irqrestore(&lnw->lock, flags);
 	return 0;
 }

 static int lnw_gpio_direction_output(struct gpio_chip *chip,
 			unsigned offset, int value)
 {
 	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
 	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
 	unsigned long flags;

 	lnw_gpio_set(chip, offset, value);
 	spin_lock_irqsave(&lnw->lock, flags);
 	value = readl(gpdr);
 	value |= BIT(offset % 32);;
 	writel(value, gpdr);
 	spin_unlock_irqrestore(&lnw->lock, flags);
 	return 0;
 }

 static int lnw_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
 	return lnw->irq_base + offset;
 }

 static int lnw_irq_type(struct irq_data *d, unsigned type)
 {
 	struct lnw_gpio *lnw = irq_data_get_irq_chip_data(d);
 	u32 gpio = d->irq - lnw->irq_base;
 	unsigned long flags;
 	u32 value;
 	void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
 	void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);

 	if (gpio >= lnw->chip.ngpio)
 		return -EINVAL;
 	spin_lock_irqsave(&lnw->lock, flags);
 	if (type & IRQ_TYPE_EDGE_RISING)
 		value = readl(grer) | BIT(gpio % 32);
 	else
 		value = readl(grer) & (~BIT(gpio % 32));
 	writel(value, grer);

 	if (type & IRQ_TYPE_EDGE_FALLING)
 		value = readl(gfer) | BIT(gpio % 32);
 	else
 		value = readl(gfer) & (~BIT(gpio % 32));
 	writel(value, gfer);
 	spin_unlock_irqrestore(&lnw->lock, flags);

 	return 0;
 }

 static void lnw_irq_unmask(struct irq_data *d)
 {
 }

 static void lnw_irq_mask(struct irq_data *d)
 {
 }

 static struct irq_chip lnw_irqchip = {
 	.name		= "LNW-GPIO",
 	.irq_mask	= lnw_irq_mask,
 	.irq_unmask	= lnw_irq_unmask,
 	.irq_set_type	= lnw_irq_type,
 };

 static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = {   /* pin number */
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f), .driver_data = 64 },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f), .driver_data = 96 },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a), .driver_data = 96 },
 	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, lnw_gpio_ids);

 static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
 {
 	struct lnw_gpio *lnw = (struct lnw_gpio *)get_irq_data(irq);
 	u32 base, gpio;
 	void __iomem *gedr;
 	u32 gedr_v;

 	/* check GPIO controller to check which pin triggered the interrupt */
 	for (base = 0; base < lnw->chip.ngpio; base += 32) {
 		gedr = gpio_reg(&lnw->chip, base, GEDR);
 		gedr_v = readl(gedr);
 		if (!gedr_v)
 			continue;
 		for (gpio = base; gpio < base + 32; gpio++)
 			if (gedr_v & BIT(gpio % 32)) {
 				pr_debug("pin %d triggered\n", gpio);
 				generic_handle_irq(lnw->irq_base + gpio);
 			}
 		/* clear the edge detect status bit */
 		writel(gedr_v, gedr);
 	}
 	desc->chip->eoi(irq);
 }

 static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
 			const struct pci_device_id *id)
 {
 	void *base;
 	int i;
 	resource_size_t start, len;
 	struct lnw_gpio *lnw;
 	u32 irq_base;
 	u32 gpio_base;
 	int retval = 0;

 	retval = pci_enable_device(pdev);
 	if (retval)
 		goto done;

 	retval = pci_request_regions(pdev, "langwell_gpio");
 	if (retval) {
 		dev_err(&pdev->dev, "error requesting resources\n");
 		goto err2;
 	}
 	/* get the irq_base from bar1 */
 	start = pci_resource_start(pdev, 1);
 	len = pci_resource_len(pdev, 1);
 	base = ioremap_nocache(start, len);
 	if (!base) {
 		dev_err(&pdev->dev, "error mapping bar1\n");
 		goto err3;
 	}
 	irq_base = *(u32 *)base;
 	gpio_base = *((u32 *)base + 1);
 	/* release the IO mapping, since we already get the info from bar1 */
 	iounmap(base);
 	/* get the register base from bar0 */
 	start = pci_resource_start(pdev, 0);
 	len = pci_resource_len(pdev, 0);
 	base = ioremap_nocache(start, len);
 	if (!base) {
 		dev_err(&pdev->dev, "error mapping bar0\n");
 		retval = -EFAULT;
 		goto err3;
 	}

 	lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
 	if (!lnw) {
 		dev_err(&pdev->dev, "can't allocate langwell_gpio chip data\n");
 		retval = -ENOMEM;
 		goto err4;
 	}
 	lnw->reg_base = base;
 	lnw->irq_base = irq_base;
 	lnw->chip.label = dev_name(&pdev->dev);
 	lnw->chip.direction_input = lnw_gpio_direction_input;
 	lnw->chip.direction_output = lnw_gpio_direction_output;
 	lnw->chip.get = lnw_gpio_get;
 	lnw->chip.set = lnw_gpio_set;
 	lnw->chip.to_irq = lnw_gpio_to_irq;
 	lnw->chip.base = gpio_base;
 	lnw->chip.ngpio = id->driver_data;
 	lnw->chip.can_sleep = 0;
 	pci_set_drvdata(pdev, lnw);
 	retval = gpiochip_add(&lnw->chip);
 	if (retval) {
 		dev_err(&pdev->dev, "langwell gpiochip_add error %d\n", retval);
 		goto err5;
 	}
 	set_irq_data(pdev->irq, lnw);
 	set_irq_chained_handler(pdev->irq, lnw_irq_handler);
 	for (i = 0; i < lnw->chip.ngpio; i++) {
 		set_irq_chip_and_handler_name(i + lnw->irq_base, &lnw_irqchip,
 					handle_simple_irq, "demux");
 		set_irq_chip_data(i + lnw->irq_base, lnw);
 	}

 	spin_lock_init(&lnw->lock);
 	goto done;
 err5:
 	kfree(lnw);
 err4:
 	iounmap(base);
 err3:
 	pci_release_regions(pdev);
 err2:
 	pci_disable_device(pdev);
 done:
 	return retval;
 }

 static struct pci_driver lnw_gpio_driver = {
 	.name		= "langwell_gpio",
 	.id_table	= lnw_gpio_ids,
 	.probe		= lnw_gpio_probe,
 };


 static int __devinit wp_gpio_probe(struct platform_device *pdev)
 {
 	struct lnw_gpio *lnw;
 	struct gpio_chip *gc;
 	struct resource *rc;
 	int retval = 0;

 	rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!rc)
 		return -EINVAL;

 	lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
 	if (!lnw) {
 		dev_err(&pdev->dev,
 			"can't allocate whitneypoint_gpio chip data\n");
 		return -ENOMEM;
 	}
 	lnw->reg_base = ioremap_nocache(rc->start, resource_size(rc));
 	if (lnw->reg_base == NULL) {
 		retval = -EINVAL;
 		goto err_kmalloc;
 	}
 	spin_lock_init(&lnw->lock);
 	gc = &lnw->chip;
 	gc->label = dev_name(&pdev->dev);
 	gc->owner = THIS_MODULE;
 	gc->direction_input = lnw_gpio_direction_input;
 	gc->direction_output = lnw_gpio_direction_output;
 	gc->get = lnw_gpio_get;
 	gc->set = lnw_gpio_set;
 	gc->to_irq = NULL;
 	gc->base = 0;
 	gc->ngpio = 64;
 	gc->can_sleep = 0;
 	retval = gpiochip_add(gc);
 	if (retval) {
 		dev_err(&pdev->dev, "whitneypoint gpiochip_add error %d\n",
 								retval);
 		goto err_ioremap;
 	}
 	platform_set_drvdata(pdev, lnw);
 	return 0;
 err_ioremap:
 	iounmap(lnw->reg_base);
 err_kmalloc:
 	kfree(lnw);
 	return retval;
 }

 static int __devexit wp_gpio_remove(struct platform_device *pdev)
 {
 	struct lnw_gpio *lnw = platform_get_drvdata(pdev);
 	int err;
 	err = gpiochip_remove(&lnw->chip);
 	if (err)
 		dev_err(&pdev->dev, "failed to remove gpio_chip.\n");
 	iounmap(lnw->reg_base);
 	kfree(lnw);
 	platform_set_drvdata(pdev, NULL);
 	return 0;
 }

 static struct platform_driver wp_gpio_driver = {
 	.probe		= wp_gpio_probe,
 	.remove		= __devexit_p(wp_gpio_remove),
 	.driver		= {
 		.name	= "wp_gpio",
 		.owner	= THIS_MODULE,
 	},
 };

 static int __init lnw_gpio_init(void)
 {
 	int ret;
 	ret =  pci_register_driver(&lnw_gpio_driver);
 	if (ret < 0)
 		return ret;
 	ret = platform_driver_register(&wp_gpio_driver);
 	if (ret < 0)
 		pci_unregister_driver(&lnw_gpio_driver);
 	return ret;
 }

 device_initcall(lnw_gpio_init);
	/* langwell_gpio.c Moorestown platform Langwell chip GPIO driver
	* Copyright (c) 2008 - 2009, Intel Corporation.
	*
	* 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.
	*/

	/* Supports:
	* Moorestown platform Langwell chip.
	* Medfield platform Penwell chip.
	* Whitney point.
	*/

	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>
	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/stddef.h>
	#include <linux/interrupt.h>
	#include <linux/init.h>
	#include <linux/irq.h>
	#include <linux/io.h>
	#include <linux/gpio.h>
	#include <linux/slab.h>

	/*
	* Langwell chip has 64 pins and thus there are 2 32bit registers to control
	* each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
	* registers to control them, so we only define the order here instead of a
	* structure, to get a bit offset for a pin (use GPDR as an example):
	*
	* nreg = ngpio / 32;
	* reg = offset / 32;
	* bit = offset % 32;
	* reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
	*
	* so the bit of reg_addr is to control pin offset's GPDR feature
	*/

	enum GPIO_REG {
	GPLR = 0, /* pin level read-only */
	GPDR, /* pin direction */
	GPSR, /* pin set */
	GPCR, /* pin clear */
	GRER, /* rising edge detect */
	GFER, /* falling edge detect */
	GEDR, /* edge detect result */
	};

	struct lnw_gpio {
	struct gpio_chip chip;
	void *reg_base;
	spinlock_t lock;
	unsigned irq_base;
	};

	static void __iomem gpio_reg(struct gpio_chip chip, unsigned offset,
	enum GPIO_REG reg_type)
	{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	unsigned nreg = chip->ngpio / 32;
	u8 reg = offset / 32;
	void __iomem *ptr;

	ptr = (void __iomem )(lnw->reg_base + reg_type nreg * 4 + reg * 4);
	return ptr;
	}

	static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
	{
	void __iomem *gplr = gpio_reg(chip, offset, GPLR);

	return readl(gplr) & BIT(offset % 32);
	}

	static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
	{
	void __iomem gpsr, gpcr;

	if (value) {
	gpsr = gpio_reg(chip, offset, GPSR);
	writel(BIT(offset % 32), gpsr);
	} else {
	gpcr = gpio_reg(chip, offset, GPCR);
	writel(BIT(offset % 32), gpcr);
	}
	}

	static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
	u32 value;
	unsigned long flags;

	spin_lock_irqsave(&lnw->lock, flags);
	value = readl(gpdr);
	value &= ~BIT(offset % 32);
	writel(value, gpdr);
	spin_unlock_irqrestore(&lnw->lock, flags);
	return 0;
	}

	static int lnw_gpio_direction_output(struct gpio_chip *chip,
	unsigned offset, int value)
	{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
	unsigned long flags;

	lnw_gpio_set(chip, offset, value);
	spin_lock_irqsave(&lnw->lock, flags);
	value = readl(gpdr);
	value \|= BIT(offset % 32);;
	writel(value, gpdr);
	spin_unlock_irqrestore(&lnw->lock, flags);
	return 0;
	}

	static int lnw_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
	{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	return lnw->irq_base + offset;
	}

	static int lnw_irq_type(struct irq_data *d, unsigned type)
	{
	struct lnw_gpio *lnw = irq_data_get_irq_chip_data(d);
	u32 gpio = d->irq - lnw->irq_base;
	unsigned long flags;
	u32 value;
	void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
	void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);

	if (gpio >= lnw->chip.ngpio)
	return -EINVAL;
	spin_lock_irqsave(&lnw->lock, flags);
	if (type & IRQ_TYPE_EDGE_RISING)
	value = readl(grer) \| BIT(gpio % 32);
	else
	value = readl(grer) & (~BIT(gpio % 32));
	writel(value, grer);

	if (type & IRQ_TYPE_EDGE_FALLING)
	value = readl(gfer) \| BIT(gpio % 32);
	else
	value = readl(gfer) & (~BIT(gpio % 32));
	writel(value, gfer);
	spin_unlock_irqrestore(&lnw->lock, flags);

	return 0;
	}

	static void lnw_irq_unmask(struct irq_data *d)
	{
	}

	static void lnw_irq_mask(struct irq_data *d)
	{
	}

	static struct irq_chip lnw_irqchip = {
	.name = "LNW-GPIO",
	.irq_mask = lnw_irq_mask,
	.irq_unmask = lnw_irq_unmask,
	.irq_set_type = lnw_irq_type,
	};

	static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = { /* pin number */
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f), .driver_data = 64 },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f), .driver_data = 96 },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a), .driver_data = 96 },
	{ 0, }
	};
	MODULE_DEVICE_TABLE(pci, lnw_gpio_ids);

	static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
	{
	struct lnw_gpio lnw = (struct lnw_gpio )get_irq_data(irq);
	u32 base, gpio;
	void __iomem *gedr;
	u32 gedr_v;

	/* check GPIO controller to check which pin triggered the interrupt */
	for (base = 0; base < lnw->chip.ngpio; base += 32) {
	gedr = gpio_reg(&lnw->chip, base, GEDR);
	gedr_v = readl(gedr);
	if (!gedr_v)
	continue;
	for (gpio = base; gpio < base + 32; gpio++)
	if (gedr_v & BIT(gpio % 32)) {
	pr_debug("pin %d triggered\n", gpio);
	generic_handle_irq(lnw->irq_base + gpio);
	}
	/* clear the edge detect status bit */
	writel(gedr_v, gedr);
	}
	desc->chip->eoi(irq);
	}

	static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
	const struct pci_device_id *id)
	{
	void *base;
	int i;
	resource_size_t start, len;
	struct lnw_gpio *lnw;
	u32 irq_base;
	u32 gpio_base;
	int retval = 0;

	retval = pci_enable_device(pdev);
	if (retval)
	goto done;

	retval = pci_request_regions(pdev, "langwell_gpio");
	if (retval) {
	dev_err(&pdev->dev, "error requesting resources\n");
	goto err2;
	}
	/* get the irq_base from bar1 */
	start = pci_resource_start(pdev, 1);
	len = pci_resource_len(pdev, 1);
	base = ioremap_nocache(start, len);
	if (!base) {
	dev_err(&pdev->dev, "error mapping bar1\n");
	goto err3;
	}
	irq_base = (u32 )base;
	gpio_base = ((u32 )base + 1);
	/* release the IO mapping, since we already get the info from bar1 */
	iounmap(base);
	/* get the register base from bar0 */
	start = pci_resource_start(pdev, 0);
	len = pci_resource_len(pdev, 0);
	base = ioremap_nocache(start, len);
	if (!base) {
	dev_err(&pdev->dev, "error mapping bar0\n");
	retval = -EFAULT;
	goto err3;
	}

	lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
	if (!lnw) {
	dev_err(&pdev->dev, "can't allocate langwell_gpio chip data\n");
	retval = -ENOMEM;
	goto err4;
	}
	lnw->reg_base = base;
	lnw->irq_base = irq_base;
	lnw->chip.label = dev_name(&pdev->dev);
	lnw->chip.direction_input = lnw_gpio_direction_input;
	lnw->chip.direction_output = lnw_gpio_direction_output;
	lnw->chip.get = lnw_gpio_get;
	lnw->chip.set = lnw_gpio_set;
	lnw->chip.to_irq = lnw_gpio_to_irq;
	lnw->chip.base = gpio_base;
	lnw->chip.ngpio = id->driver_data;
	lnw->chip.can_sleep = 0;
	pci_set_drvdata(pdev, lnw);
	retval = gpiochip_add(&lnw->chip);
	if (retval) {
	dev_err(&pdev->dev, "langwell gpiochip_add error %d\n", retval);
	goto err5;
	}
	set_irq_data(pdev->irq, lnw);
	set_irq_chained_handler(pdev->irq, lnw_irq_handler);
	for (i = 0; i < lnw->chip.ngpio; i++) {
	set_irq_chip_and_handler_name(i + lnw->irq_base, &lnw_irqchip,
	handle_simple_irq, "demux");
	set_irq_chip_data(i + lnw->irq_base, lnw);
	}

	spin_lock_init(&lnw->lock);
	goto done;
	err5:
	kfree(lnw);
	err4:
	iounmap(base);
	err3:
	pci_release_regions(pdev);
	err2:
	pci_disable_device(pdev);
	done:
	return retval;
	}

	static struct pci_driver lnw_gpio_driver = {
	.name = "langwell_gpio",
	.id_table = lnw_gpio_ids,
	.probe = lnw_gpio_probe,
	};


	static int __devinit wp_gpio_probe(struct platform_device *pdev)
	{
	struct lnw_gpio *lnw;
	struct gpio_chip *gc;
	struct resource *rc;
	int retval = 0;

	rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!rc)
	return -EINVAL;

	lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
	if (!lnw) {
	dev_err(&pdev->dev,
	"can't allocate whitneypoint_gpio chip data\n");
	return -ENOMEM;
	}
	lnw->reg_base = ioremap_nocache(rc->start, resource_size(rc));
	if (lnw->reg_base == NULL) {
	retval = -EINVAL;
	goto err_kmalloc;
	}
	spin_lock_init(&lnw->lock);
	gc = &lnw->chip;
	gc->label = dev_name(&pdev->dev);
	gc->owner = THIS_MODULE;
	gc->direction_input = lnw_gpio_direction_input;
	gc->direction_output = lnw_gpio_direction_output;
	gc->get = lnw_gpio_get;
	gc->set = lnw_gpio_set;
	gc->to_irq = NULL;
	gc->base = 0;
	gc->ngpio = 64;
	gc->can_sleep = 0;
	retval = gpiochip_add(gc);
	if (retval) {
	dev_err(&pdev->dev, "whitneypoint gpiochip_add error %d\n",
	retval);
	goto err_ioremap;
	}
	platform_set_drvdata(pdev, lnw);
	return 0;
	err_ioremap:
	iounmap(lnw->reg_base);
	err_kmalloc:
	kfree(lnw);
	return retval;
	}

	static int __devexit wp_gpio_remove(struct platform_device *pdev)
	{
	struct lnw_gpio *lnw = platform_get_drvdata(pdev);
	int err;
	err = gpiochip_remove(&lnw->chip);
	if (err)
	dev_err(&pdev->dev, "failed to remove gpio_chip.\n");
	iounmap(lnw->reg_base);
	kfree(lnw);
	platform_set_drvdata(pdev, NULL);
	return 0;
	}

	static struct platform_driver wp_gpio_driver = {
	.probe = wp_gpio_probe,
	.remove = __devexit_p(wp_gpio_remove),
	.driver = {
	.name = "wp_gpio",
	.owner = THIS_MODULE,
	},
	};

	static int __init lnw_gpio_init(void)
	{
	int ret;
	ret = pci_register_driver(&lnw_gpio_driver);
	if (ret < 0)
	return ret;
	ret = platform_driver_register(&wp_gpio_driver);
	if (ret < 0)
	pci_unregister_driver(&lnw_gpio_driver);
	return ret;
	}

	device_initcall(lnw_gpio_init);