drivers/gpio/cs5535-gpio.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * AMD CS5535/CS5536 GPIO driver
  * Copyright (C) 2006  Advanced Micro Devices, Inc.
  * Copyright (C) 2007-2009  Andres Salomon <dilinger@collabora.co.uk>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public License
  * as published by the Free Software Foundation.
  */

 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/gpio.h>
 #include <linux/io.h>
 #include <linux/cs5535.h>
 #include <asm/msr.h>

 #define DRV_NAME "cs5535-gpio"
 #define GPIO_BAR 1

 /*
  * Some GPIO pins
  *  31-29,23 : reserved (always mask out)
  *  28       : Power Button
  *  26       : PME#
  *  22-16    : LPC
  *  14,15    : SMBus
  *  9,8      : UART1
  *  7        : PCI INTB
  *  3,4      : UART2/DDC
  *  2        : IDE_IRQ0
  *  1        : AC_BEEP
  *  0        : PCI INTA
  *
  * If a mask was not specified, allow all except
  * reserved and Power Button
  */
 #define GPIO_DEFAULT_MASK 0x0F7FFFFF

 static ulong mask = GPIO_DEFAULT_MASK;
 module_param_named(mask, mask, ulong, 0444);
 MODULE_PARM_DESC(mask, "GPIO channel mask.");

 static struct cs5535_gpio_chip {
 	struct gpio_chip chip;
 	resource_size_t base;

 	struct pci_dev *pdev;
 	spinlock_t lock;
 } cs5535_gpio_chip;

 /*
  * The CS5535/CS5536 GPIOs support a number of extra features not defined
  * by the gpio_chip API, so these are exported.  For a full list of the
  * registers, see include/linux/cs5535.h.
  */

 static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
 		unsigned int reg)
 {
 	unsigned long addr = chip->base + 0x80 + reg;

 	/*
 	 * According to the CS5536 errata (#36), after suspend
 	 * a write to the high bank GPIO register will clear all
 	 * non-selected bits; the recommended workaround is a
 	 * read-modify-write operation.
 	 *
 	 * Don't apply this errata to the edge status GPIOs, as writing
 	 * to their lower bits will clear them.
 	 */
 	if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
 		if (val & 0xffff)
 			val |= (inl(addr) & 0xffff); /* ignore the high bits */
 		else
 			val |= (inl(addr) ^ (val >> 16));
 	}
 	outl(val, addr);
 }

 static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
 		unsigned int reg)
 {
 	if (offset < 16)
 		/* low bank register */
 		outl(1 << offset, chip->base + reg);
 	else
 		/* high bank register */
 		errata_outl(chip, 1 << (offset - 16), reg);
 }

 void cs5535_gpio_set(unsigned offset, unsigned int reg)
 {
 	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);
 	__cs5535_gpio_set(chip, offset, reg);
 	spin_unlock_irqrestore(&chip->lock, flags);
 }
 EXPORT_SYMBOL_GPL(cs5535_gpio_set);

 static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
 		unsigned int reg)
 {
 	if (offset < 16)
 		/* low bank register */
 		outl(1 << (offset + 16), chip->base + reg);
 	else
 		/* high bank register */
 		errata_outl(chip, 1 << offset, reg);
 }

 void cs5535_gpio_clear(unsigned offset, unsigned int reg)
 {
 	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);
 	__cs5535_gpio_clear(chip, offset, reg);
 	spin_unlock_irqrestore(&chip->lock, flags);
 }
 EXPORT_SYMBOL_GPL(cs5535_gpio_clear);

 int cs5535_gpio_isset(unsigned offset, unsigned int reg)
 {
 	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 	unsigned long flags;
 	long val;

 	spin_lock_irqsave(&chip->lock, flags);
 	if (offset < 16)
 		/* low bank register */
 		val = inl(chip->base + reg);
 	else {
 		/* high bank register */
 		val = inl(chip->base + 0x80 + reg);
 		offset -= 16;
 	}
 	spin_unlock_irqrestore(&chip->lock, flags);

 	return (val & (1 << offset)) ? 1 : 0;
 }
 EXPORT_SYMBOL_GPL(cs5535_gpio_isset);

 int cs5535_gpio_set_irq(unsigned group, unsigned irq)
 {
 	uint32_t lo, hi;

 	if (group > 7 || irq > 15)
 		return -EINVAL;

 	rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);

 	lo &= ~(0xF << (group * 4));
 	lo |= (irq & 0xF) << (group * 4);

 	wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);

 void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
 {
 	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 	uint32_t shift = (offset % 8) * 4;
 	unsigned long flags;
 	uint32_t val;

 	if (offset >= 24)
 		offset = GPIO_MAP_W;
 	else if (offset >= 16)
 		offset = GPIO_MAP_Z;
 	else if (offset >= 8)
 		offset = GPIO_MAP_Y;
 	else
 		offset = GPIO_MAP_X;

 	spin_lock_irqsave(&chip->lock, flags);
 	val = inl(chip->base + offset);

 	/* Clear whatever was there before */
 	val &= ~(0xF << shift);

 	/* Set the new value */
 	val |= ((pair & 7) << shift);

 	/* Set the PME bit if this is a PME event */
 	if (pme)
 		val |= (1 << (shift + 3));

 	outl(val, chip->base + offset);
 	spin_unlock_irqrestore(&chip->lock, flags);
 }
 EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);

 /*
  * Generic gpio_chip API support.
  */

 static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
 {
 	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);

 	/* check if this pin is available */
 	if ((mask & (1 << offset)) == 0) {
 		dev_info(&chip->pdev->dev,
 			"pin %u is not available (check mask)\n", offset);
 		spin_unlock_irqrestore(&chip->lock, flags);
 		return -EINVAL;
 	}

 	/* disable output aux 1 & 2 on this pin */
 	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
 	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);

 	/* disable input aux 1 on this pin */
 	__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);

 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	return cs5535_gpio_isset(offset, GPIO_READ_BACK);
 }

 static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 {
 	if (val)
 		cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
 	else
 		cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
 }

 static int chip_direction_input(struct gpio_chip *c, unsigned offset)
 {
 	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);
 	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
 	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
 {
 	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);

 	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
 	__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
 	if (val)
 		__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
 	else
 		__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);

 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static const char * const cs5535_gpio_names[] = {
 	"GPIO0", "GPIO1", "GPIO2", "GPIO3",
 	"GPIO4", "GPIO5", "GPIO6", "GPIO7",
 	"GPIO8", "GPIO9", "GPIO10", "GPIO11",
 	"GPIO12", "GPIO13", "GPIO14", "GPIO15",
 	"GPIO16", "GPIO17", "GPIO18", "GPIO19",
 	"GPIO20", "GPIO21", "GPIO22", NULL,
 	"GPIO24", "GPIO25", "GPIO26", "GPIO27",
 	"GPIO28", NULL, NULL, NULL,
 };

 static struct cs5535_gpio_chip cs5535_gpio_chip = {
 	.chip = {
 		.owner = THIS_MODULE,
 		.label = DRV_NAME,

 		.base = 0,
 		.ngpio = 32,
 		.names = cs5535_gpio_names,
 		.request = chip_gpio_request,

 		.get = chip_gpio_get,
 		.set = chip_gpio_set,

 		.direction_input = chip_direction_input,
 		.direction_output = chip_direction_output,
 	},
 };

 static int __init cs5535_gpio_probe(struct pci_dev *pdev,
 		const struct pci_device_id *pci_id)
 {
 	int err;
 	ulong mask_orig = mask;

 	/* There are two ways to get the GPIO base address; one is by
 	 * fetching it from MSR_LBAR_GPIO, the other is by reading the
 	 * PCI BAR info.  The latter method is easier (especially across
 	 * different architectures), so we'll stick with that for now.  If
 	 * it turns out to be unreliable in the face of crappy BIOSes, we
 	 * can always go back to using MSRs.. */

 	err = pci_enable_device_io(pdev);
 	if (err) {
 		dev_err(&pdev->dev, "can't enable device IO\n");
 		goto done;
 	}

 	err = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
 	if (err) {
 		dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
 		goto done;
 	}

 	/* set up the driver-specific struct */
 	cs5535_gpio_chip.base = pci_resource_start(pdev, GPIO_BAR);
 	cs5535_gpio_chip.pdev = pdev;
 	spin_lock_init(&cs5535_gpio_chip.lock);

 	dev_info(&pdev->dev, "allocated PCI BAR #%d: base 0x%llx\n", GPIO_BAR,
 			(unsigned long long) cs5535_gpio_chip.base);

 	/* mask out reserved pins */
 	mask &= 0x1F7FFFFF;

 	/* do not allow pin 28, Power Button, as there's special handling
 	 * in the PMC needed. (note 12, p. 48) */
 	mask &= ~(1 << 28);

 	if (mask_orig != mask)
 		dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
 				mask_orig, mask);

 	/* finally, register with the generic GPIO API */
 	err = gpiochip_add(&cs5535_gpio_chip.chip);
 	if (err)
 		goto release_region;

 	dev_info(&pdev->dev, DRV_NAME ": GPIO support successfully loaded.\n");
 	return 0;

 release_region:
 	pci_release_region(pdev, GPIO_BAR);
 done:
 	return err;
 }

 static void __exit cs5535_gpio_remove(struct pci_dev *pdev)
 {
 	int err;

 	err = gpiochip_remove(&cs5535_gpio_chip.chip);
 	if (err) {
 		/* uhh? */
 		dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
 	}
 	pci_release_region(pdev, GPIO_BAR);
 }

 static struct pci_device_id cs5535_gpio_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_gpio_pci_tbl);

 /*
  * We can't use the standard PCI driver registration stuff here, since
  * that allows only one driver to bind to each PCI device (and we want
  * multiple drivers to be able to bind to the device).  Instead, manually
  * scan for the PCI device, request a single region, and keep track of the
  * devices that we're using.
  */

 static int __init cs5535_gpio_scan_pci(void)
 {
 	struct pci_dev *pdev;
 	int err = -ENODEV;
 	int i;

 	for (i = 0; i < ARRAY_SIZE(cs5535_gpio_pci_tbl); i++) {
 		pdev = pci_get_device(cs5535_gpio_pci_tbl[i].vendor,
 				cs5535_gpio_pci_tbl[i].device, NULL);
 		if (pdev) {
 			err = cs5535_gpio_probe(pdev, &cs5535_gpio_pci_tbl[i]);
 			if (err)
 				pci_dev_put(pdev);

 			/* we only support a single CS5535/6 southbridge */
 			break;
 		}
 	}

 	return err;
 }

 static void __exit cs5535_gpio_free_pci(void)
 {
 	cs5535_gpio_remove(cs5535_gpio_chip.pdev);
 	pci_dev_put(cs5535_gpio_chip.pdev);
 }

 static int __init cs5535_gpio_init(void)
 {
 	return cs5535_gpio_scan_pci();
 }

 static void __exit cs5535_gpio_exit(void)
 {
 	cs5535_gpio_free_pci();
 }

 module_init(cs5535_gpio_init);
 module_exit(cs5535_gpio_exit);

 MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
 MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
 MODULE_LICENSE("GPL");
	/*
	* AMD CS5535/CS5536 GPIO driver
	* Copyright (C) 2006 Advanced Micro Devices, Inc.
	* Copyright (C) 2007-2009 Andres Salomon <dilinger@collabora.co.uk>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of version 2 of the GNU General Public License
	* as published by the Free Software Foundation.
	*/

	#include <linux/kernel.h>
	#include <linux/spinlock.h>
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/gpio.h>
	#include <linux/io.h>
	#include <linux/cs5535.h>
	#include <asm/msr.h>

	#define DRV_NAME "cs5535-gpio"
	#define GPIO_BAR 1

	/*
	* Some GPIO pins
	* 31-29,23 : reserved (always mask out)
	* 28 : Power Button
	* 26 : PME#
	* 22-16 : LPC
	* 14,15 : SMBus
	* 9,8 : UART1
	* 7 : PCI INTB
	* 3,4 : UART2/DDC
	* 2 : IDE_IRQ0
	* 1 : AC_BEEP
	* 0 : PCI INTA
	*
	* If a mask was not specified, allow all except
	* reserved and Power Button
	*/
	#define GPIO_DEFAULT_MASK 0x0F7FFFFF

	static ulong mask = GPIO_DEFAULT_MASK;
	module_param_named(mask, mask, ulong, 0444);
	MODULE_PARM_DESC(mask, "GPIO channel mask.");

	static struct cs5535_gpio_chip {
	struct gpio_chip chip;
	resource_size_t base;

	struct pci_dev *pdev;
	spinlock_t lock;
	} cs5535_gpio_chip;

	/*
	* The CS5535/CS5536 GPIOs support a number of extra features not defined
	* by the gpio_chip API, so these are exported. For a full list of the
	* registers, see include/linux/cs5535.h.
	*/

	static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
	unsigned int reg)
	{
	unsigned long addr = chip->base + 0x80 + reg;

	/*
	* According to the CS5536 errata (#36), after suspend
	* a write to the high bank GPIO register will clear all
	* non-selected bits; the recommended workaround is a
	* read-modify-write operation.
	*
	* Don't apply this errata to the edge status GPIOs, as writing
	* to their lower bits will clear them.
	*/
	if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
	if (val & 0xffff)
	val \|= (inl(addr) & 0xffff); /* ignore the high bits */
	else
	val \|= (inl(addr) ^ (val >> 16));
	}
	outl(val, addr);
	}

	static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
	unsigned int reg)
	{
	if (offset < 16)
	/* low bank register */
	outl(1 << offset, chip->base + reg);
	else
	/* high bank register */
	errata_outl(chip, 1 << (offset - 16), reg);
	}

	void cs5535_gpio_set(unsigned offset, unsigned int reg)
	{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_set(chip, offset, reg);
	spin_unlock_irqrestore(&chip->lock, flags);
	}
	EXPORT_SYMBOL_GPL(cs5535_gpio_set);

	static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
	unsigned int reg)
	{
	if (offset < 16)
	/* low bank register */
	outl(1 << (offset + 16), chip->base + reg);
	else
	/* high bank register */
	errata_outl(chip, 1 << offset, reg);
	}

	void cs5535_gpio_clear(unsigned offset, unsigned int reg)
	{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_clear(chip, offset, reg);
	spin_unlock_irqrestore(&chip->lock, flags);
	}
	EXPORT_SYMBOL_GPL(cs5535_gpio_clear);

	int cs5535_gpio_isset(unsigned offset, unsigned int reg)
	{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;
	long val;

	spin_lock_irqsave(&chip->lock, flags);
	if (offset < 16)
	/* low bank register */
	val = inl(chip->base + reg);
	else {
	/* high bank register */
	val = inl(chip->base + 0x80 + reg);
	offset -= 16;
	}
	spin_unlock_irqrestore(&chip->lock, flags);

	return (val & (1 << offset)) ? 1 : 0;
	}
	EXPORT_SYMBOL_GPL(cs5535_gpio_isset);

	int cs5535_gpio_set_irq(unsigned group, unsigned irq)
	{
	uint32_t lo, hi;

	if (group > 7 \|\| irq > 15)
	return -EINVAL;

	rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);

	lo &= ~(0xF << (group * 4));
	lo \|= (irq & 0xF) << (group * 4);

	wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
	return 0;
	}
	EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);

	void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
	{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	uint32_t shift = (offset % 8) * 4;
	unsigned long flags;
	uint32_t val;

	if (offset >= 24)
	offset = GPIO_MAP_W;
	else if (offset >= 16)
	offset = GPIO_MAP_Z;
	else if (offset >= 8)
	offset = GPIO_MAP_Y;
	else
	offset = GPIO_MAP_X;

	spin_lock_irqsave(&chip->lock, flags);
	val = inl(chip->base + offset);

	/* Clear whatever was there before */
	val &= ~(0xF << shift);

	/* Set the new value */
	val \|= ((pair & 7) << shift);

	/* Set the PME bit if this is a PME event */
	if (pme)
	val \|= (1 << (shift + 3));

	outl(val, chip->base + offset);
	spin_unlock_irqrestore(&chip->lock, flags);
	}
	EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);

	/*
	* Generic gpio_chip API support.
	*/

	static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
	{
	struct cs5535_gpio_chip chip = (struct cs5535_gpio_chip ) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);

	/* check if this pin is available */
	if ((mask & (1 << offset)) == 0) {
	dev_info(&chip->pdev->dev,
	"pin %u is not available (check mask)\n", offset);
	spin_unlock_irqrestore(&chip->lock, flags);
	return -EINVAL;
	}

	/* disable output aux 1 & 2 on this pin */
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);

	/* disable input aux 1 on this pin */
	__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
	{
	return cs5535_gpio_isset(offset, GPIO_READ_BACK);
	}

	static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
	{
	if (val)
	cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
	else
	cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
	}

	static int chip_direction_input(struct gpio_chip *c, unsigned offset)
	{
	struct cs5535_gpio_chip chip = (struct cs5535_gpio_chip ) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
	{
	struct cs5535_gpio_chip chip = (struct cs5535_gpio_chip ) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);

	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
	__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
	if (val)
	__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
	else
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static const char * const cs5535_gpio_names[] = {
	"GPIO0", "GPIO1", "GPIO2", "GPIO3",
	"GPIO4", "GPIO5", "GPIO6", "GPIO7",
	"GPIO8", "GPIO9", "GPIO10", "GPIO11",
	"GPIO12", "GPIO13", "GPIO14", "GPIO15",
	"GPIO16", "GPIO17", "GPIO18", "GPIO19",
	"GPIO20", "GPIO21", "GPIO22", NULL,
	"GPIO24", "GPIO25", "GPIO26", "GPIO27",
	"GPIO28", NULL, NULL, NULL,
	};

	static struct cs5535_gpio_chip cs5535_gpio_chip = {
	.chip = {
	.owner = THIS_MODULE,
	.label = DRV_NAME,

	.base = 0,
	.ngpio = 32,
	.names = cs5535_gpio_names,
	.request = chip_gpio_request,

	.get = chip_gpio_get,
	.set = chip_gpio_set,

	.direction_input = chip_direction_input,
	.direction_output = chip_direction_output,
	},
	};

	static int __init cs5535_gpio_probe(struct pci_dev *pdev,
	const struct pci_device_id *pci_id)
	{
	int err;
	ulong mask_orig = mask;

	/* There are two ways to get the GPIO base address; one is by
	* fetching it from MSR_LBAR_GPIO, the other is by reading the
	* PCI BAR info. The latter method is easier (especially across
	* different architectures), so we'll stick with that for now. If
	* it turns out to be unreliable in the face of crappy BIOSes, we
	* can always go back to using MSRs.. */

	err = pci_enable_device_io(pdev);
	if (err) {
	dev_err(&pdev->dev, "can't enable device IO\n");
	goto done;
	}

	err = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
	if (err) {
	dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
	goto done;
	}

	/* set up the driver-specific struct */
	cs5535_gpio_chip.base = pci_resource_start(pdev, GPIO_BAR);
	cs5535_gpio_chip.pdev = pdev;
	spin_lock_init(&cs5535_gpio_chip.lock);

	dev_info(&pdev->dev, "allocated PCI BAR #%d: base 0x%llx\n", GPIO_BAR,
	(unsigned long long) cs5535_gpio_chip.base);

	/* mask out reserved pins */
	mask &= 0x1F7FFFFF;

	/* do not allow pin 28, Power Button, as there's special handling
	* in the PMC needed. (note 12, p. 48) */
	mask &= ~(1 << 28);

	if (mask_orig != mask)
	dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
	mask_orig, mask);

	/* finally, register with the generic GPIO API */
	err = gpiochip_add(&cs5535_gpio_chip.chip);
	if (err)
	goto release_region;

	dev_info(&pdev->dev, DRV_NAME ": GPIO support successfully loaded.\n");
	return 0;

	release_region:
	pci_release_region(pdev, GPIO_BAR);
	done:
	return err;
	}

	static void __exit cs5535_gpio_remove(struct pci_dev *pdev)
	{
	int err;

	err = gpiochip_remove(&cs5535_gpio_chip.chip);
	if (err) {
	/* uhh? */
	dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
	}
	pci_release_region(pdev, GPIO_BAR);
	}

	static struct pci_device_id cs5535_gpio_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_gpio_pci_tbl);

	/*
	* We can't use the standard PCI driver registration stuff here, since
	* that allows only one driver to bind to each PCI device (and we want
	* multiple drivers to be able to bind to the device). Instead, manually
	* scan for the PCI device, request a single region, and keep track of the
	* devices that we're using.
	*/

	static int __init cs5535_gpio_scan_pci(void)
	{
	struct pci_dev *pdev;
	int err = -ENODEV;
	int i;

	for (i = 0; i < ARRAY_SIZE(cs5535_gpio_pci_tbl); i++) {
	pdev = pci_get_device(cs5535_gpio_pci_tbl[i].vendor,
	cs5535_gpio_pci_tbl[i].device, NULL);
	if (pdev) {
	err = cs5535_gpio_probe(pdev, &cs5535_gpio_pci_tbl[i]);
	if (err)
	pci_dev_put(pdev);

	/* we only support a single CS5535/6 southbridge */
	break;
	}
	}

	return err;
	}

	static void __exit cs5535_gpio_free_pci(void)
	{
	cs5535_gpio_remove(cs5535_gpio_chip.pdev);
	pci_dev_put(cs5535_gpio_chip.pdev);
	}

	static int __init cs5535_gpio_init(void)
	{
	return cs5535_gpio_scan_pci();
	}

	static void __exit cs5535_gpio_exit(void)
	{
	cs5535_gpio_free_pci();
	}

	module_init(cs5535_gpio_init);
	module_exit(cs5535_gpio_exit);

	MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
	MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
	MODULE_LICENSE("GPL");