drivers/gpio/gpio-ich.c - SHIFTPHONES/mainline/linux - Gitiles

 /*
  * Intel ICH6-10, Series 5 and 6 GPIO driver
  *
  * Copyright (C) 2010 Extreme Engineering Solutions.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * 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.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/gpio.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/lpc_ich.h>

 #define DRV_NAME "gpio_ich"

 /*
  * GPIO register offsets in GPIO I/O space.
  * Each chunk of 32 GPIOs is manipulated via its own USE_SELx, IO_SELx, and
  * LVLx registers.  Logic in the read/write functions takes a register and
  * an absolute bit number and determines the proper register offset and bit
  * number in that register.  For example, to read the value of GPIO bit 50
  * the code would access offset ichx_regs[2(=GPIO_LVL)][1(=50/32)],
  * bit 18 (50%32).
  */
 enum GPIO_REG {
 	GPIO_USE_SEL = 0,
 	GPIO_IO_SEL,
 	GPIO_LVL,
 	GPO_BLINK
 };

 static const u8 ichx_regs[4][3] = {
 	{0x00, 0x30, 0x40},	/* USE_SEL[1-3] offsets */
 	{0x04, 0x34, 0x44},	/* IO_SEL[1-3] offsets */
 	{0x0c, 0x38, 0x48},	/* LVL[1-3] offsets */
 	{0x18, 0x18, 0x18},	/* BLINK offset */
 };

 static const u8 ichx_reglen[3] = {
 	0x30, 0x10, 0x10,
 };

 #define ICHX_WRITE(val, reg, base_res)	outl(val, (reg) + (base_res)->start)
 #define ICHX_READ(reg, base_res)	inl((reg) + (base_res)->start)

 struct ichx_desc {
 	/* Max GPIO pins the chipset can have */
 	uint ngpio;

 	/* chipset registers */
 	const u8 (*regs)[3];
 	const u8 *reglen;

 	/* GPO_BLINK is available on this chipset */
 	bool have_blink;

 	/* Whether the chipset has GPIO in GPE0_STS in the PM IO region */
 	bool uses_gpe0;

 	/* USE_SEL is bogus on some chipsets, eg 3100 */
 	u32 use_sel_ignore[3];

 	/* Some chipsets have quirks, let these use their own request/get */
 	int (*request)(struct gpio_chip *chip, unsigned offset);
 	int (*get)(struct gpio_chip *chip, unsigned offset);

 	/*
 	 * Some chipsets don't let reading output values on GPIO_LVL register
 	 * this option allows driver caching written output values
 	 */
 	bool use_outlvl_cache;
 };

 static struct {
 	spinlock_t lock;
 	struct platform_device *dev;
 	struct gpio_chip chip;
 	struct resource *gpio_base;	/* GPIO IO base */
 	struct resource *pm_base;	/* Power Mangagment IO base */
 	struct ichx_desc *desc;	/* Pointer to chipset-specific description */
 	u32 orig_gpio_ctrl;	/* Orig CTRL value, used to restore on exit */
 	u8 use_gpio;		/* Which GPIO groups are usable */
 	int outlvl_cache[3];	/* cached output values */
 } ichx_priv;

 static int modparam_gpiobase = -1;	/* dynamic */
 module_param_named(gpiobase, modparam_gpiobase, int, 0444);
 MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, "
 			   "which is the default.");

 static int ichx_write_bit(int reg, unsigned nr, int val, int verify)
 {
 	unsigned long flags;
 	u32 data, tmp;
 	int reg_nr = nr / 32;
 	int bit = nr & 0x1f;
 	int ret = 0;

 	spin_lock_irqsave(&ichx_priv.lock, flags);

 	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
 		data = ichx_priv.outlvl_cache[reg_nr];
 	else
 		data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
 				 ichx_priv.gpio_base);

 	if (val)
 		data |= 1 << bit;
 	else
 		data &= ~(1 << bit);
 	ICHX_WRITE(data, ichx_priv.desc->regs[reg][reg_nr],
 			 ichx_priv.gpio_base);
 	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
 		ichx_priv.outlvl_cache[reg_nr] = data;

 	tmp = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
 			ichx_priv.gpio_base);
 	if (verify && data != tmp)
 		ret = -EPERM;

 	spin_unlock_irqrestore(&ichx_priv.lock, flags);

 	return ret;
 }

 static int ichx_read_bit(int reg, unsigned nr)
 {
 	unsigned long flags;
 	u32 data;
 	int reg_nr = nr / 32;
 	int bit = nr & 0x1f;

 	spin_lock_irqsave(&ichx_priv.lock, flags);

 	data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
 			 ichx_priv.gpio_base);

 	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
 		data = ichx_priv.outlvl_cache[reg_nr] | data;

 	spin_unlock_irqrestore(&ichx_priv.lock, flags);

 	return data & (1 << bit) ? 1 : 0;
 }

 static bool ichx_gpio_check_available(struct gpio_chip *gpio, unsigned nr)
 {
 	return !!(ichx_priv.use_gpio & (1 << (nr / 32)));
 }

 static int ichx_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
 {
 	/*
 	 * Try setting pin as an input and verify it worked since many pins
 	 * are output-only.
 	 */
 	if (ichx_write_bit(GPIO_IO_SEL, nr, 1, 1))
 		return -EINVAL;

 	return 0;
 }

 static int ichx_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 					int val)
 {
 	/* Disable blink hardware which is available for GPIOs from 0 to 31. */
 	if (nr < 32 && ichx_priv.desc->have_blink)
 		ichx_write_bit(GPO_BLINK, nr, 0, 0);

 	/* Set GPIO output value. */
 	ichx_write_bit(GPIO_LVL, nr, val, 0);

 	/*
 	 * Try setting pin as an output and verify it worked since many pins
 	 * are input-only.
 	 */
 	if (ichx_write_bit(GPIO_IO_SEL, nr, 0, 1))
 		return -EINVAL;

 	return 0;
 }

 static int ichx_gpio_get(struct gpio_chip *chip, unsigned nr)
 {
 	return ichx_read_bit(GPIO_LVL, nr);
 }

 static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr)
 {
 	unsigned long flags;
 	u32 data;

 	/*
 	 * GPI 0 - 15 need to be read from the power management registers on
 	 * a ICH6/3100 bridge.
 	 */
 	if (nr < 16) {
 		if (!ichx_priv.pm_base)
 			return -ENXIO;

 		spin_lock_irqsave(&ichx_priv.lock, flags);

 		/* GPI 0 - 15 are latched, write 1 to clear*/
 		ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base);
 		data = ICHX_READ(0, ichx_priv.pm_base);

 		spin_unlock_irqrestore(&ichx_priv.lock, flags);

 		return (data >> 16) & (1 << nr) ? 1 : 0;
 	} else {
 		return ichx_gpio_get(chip, nr);
 	}
 }

 static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr)
 {
 	if (!ichx_gpio_check_available(chip, nr))
 		return -ENXIO;

 	/*
 	 * Note we assume the BIOS properly set a bridge's USE value.  Some
 	 * chips (eg Intel 3100) have bogus USE values though, so first see if
 	 * the chipset's USE value can be trusted for this specific bit.
 	 * If it can't be trusted, assume that the pin can be used as a GPIO.
 	 */
 	if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f)))
 		return 0;

 	return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV;
 }

 static int ich6_gpio_request(struct gpio_chip *chip, unsigned nr)
 {
 	/*
 	 * Fixups for bits 16 and 17 are necessary on the Intel ICH6/3100
 	 * bridge as they are controlled by USE register bits 0 and 1.  See
 	 * "Table 704 GPIO_USE_SEL1 register" in the i3100 datasheet for
 	 * additional info.
 	 */
 	if (nr == 16 || nr == 17)
 		nr -= 16;

 	return ichx_gpio_request(chip, nr);
 }

 static void ichx_gpio_set(struct gpio_chip *chip, unsigned nr, int val)
 {
 	ichx_write_bit(GPIO_LVL, nr, val, 0);
 }

 static void ichx_gpiolib_setup(struct gpio_chip *chip)
 {
 	chip->owner = THIS_MODULE;
 	chip->label = DRV_NAME;
 	chip->dev = &ichx_priv.dev->dev;

 	/* Allow chip-specific overrides of request()/get() */
 	chip->request = ichx_priv.desc->request ?
 		ichx_priv.desc->request : ichx_gpio_request;
 	chip->get = ichx_priv.desc->get ?
 		ichx_priv.desc->get : ichx_gpio_get;

 	chip->set = ichx_gpio_set;
 	chip->direction_input = ichx_gpio_direction_input;
 	chip->direction_output = ichx_gpio_direction_output;
 	chip->base = modparam_gpiobase;
 	chip->ngpio = ichx_priv.desc->ngpio;
 	chip->can_sleep = false;
 	chip->dbg_show = NULL;
 }

 /* ICH6-based, 631xesb-based */
 static struct ichx_desc ich6_desc = {
 	/* Bridges using the ICH6 controller need fixups for GPIO 0 - 17 */
 	.request = ich6_gpio_request,
 	.get = ich6_gpio_get,

 	/* GPIO 0-15 are read in the GPE0_STS PM register */
 	.uses_gpe0 = true,

 	.ngpio = 50,
 	.have_blink = true,
 };

 /* Intel 3100 */
 static struct ichx_desc i3100_desc = {
 	/*
 	 * Bits 16,17, 20 of USE_SEL and bit 16 of USE_SEL2 always read 0 on
 	 * the Intel 3100.  See "Table 712. GPIO Summary Table" of 3100
 	 * Datasheet for more info.
 	 */
 	.use_sel_ignore = {0x00130000, 0x00010000, 0x0},

 	/* The 3100 needs fixups for GPIO 0 - 17 */
 	.request = ich6_gpio_request,
 	.get = ich6_gpio_get,

 	/* GPIO 0-15 are read in the GPE0_STS PM register */
 	.uses_gpe0 = true,

 	.ngpio = 50,
 };

 /* ICH7 and ICH8-based */
 static struct ichx_desc ich7_desc = {
 	.ngpio = 50,
 	.have_blink = true,
 	.regs = ichx_regs,
 	.reglen = ichx_reglen,
 };

 /* ICH9-based */
 static struct ichx_desc ich9_desc = {
 	.ngpio = 61,
 	.have_blink = true,
 	.regs = ichx_regs,
 	.reglen = ichx_reglen,
 };

 /* ICH10-based - Consumer/corporate versions have different amount of GPIO */
 static struct ichx_desc ich10_cons_desc = {
 	.ngpio = 61,
 	.have_blink = true,
 	.regs = ichx_regs,
 	.reglen = ichx_reglen,
 };
 static struct ichx_desc ich10_corp_desc = {
 	.ngpio = 72,
 	.have_blink = true,
 	.regs = ichx_regs,
 	.reglen = ichx_reglen,
 };

 /* Intel 5 series, 6 series, 3400 series, and C200 series */
 static struct ichx_desc intel5_desc = {
 	.ngpio = 76,
 	.regs = ichx_regs,
 	.reglen = ichx_reglen,
 };

 static int ichx_gpio_request_regions(struct resource *res_base,
 						const char *name, u8 use_gpio)
 {
 	int i;

 	if (!res_base || !res_base->start || !res_base->end)
 		return -ENODEV;

 	for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) {
 		if (!(use_gpio & (1 << i)))
 			continue;
 		if (!request_region(
 				res_base->start + ichx_priv.desc->regs[0][i],
 				ichx_priv.desc->reglen[i], name))
 			goto request_err;
 	}
 	return 0;

 request_err:
 	/* Clean up: release already requested regions, if any */
 	for (i--; i >= 0; i--) {
 		if (!(use_gpio & (1 << i)))
 			continue;
 		release_region(res_base->start + ichx_priv.desc->regs[0][i],
 			       ichx_priv.desc->reglen[i]);
 	}
 	return -EBUSY;
 }

 static void ichx_gpio_release_regions(struct resource *res_base, u8 use_gpio)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) {
 		if (!(use_gpio & (1 << i)))
 			continue;
 		release_region(res_base->start + ichx_priv.desc->regs[0][i],
 			       ichx_priv.desc->reglen[i]);
 	}
 }

 static int ichx_gpio_probe(struct platform_device *pdev)
 {
 	struct resource *res_base, *res_pm;
 	int err;
 	struct lpc_ich_info *ich_info = dev_get_platdata(&pdev->dev);

 	if (!ich_info)
 		return -ENODEV;

 	ichx_priv.dev = pdev;

 	switch (ich_info->gpio_version) {
 	case ICH_I3100_GPIO:
 		ichx_priv.desc = &i3100_desc;
 		break;
 	case ICH_V5_GPIO:
 		ichx_priv.desc = &intel5_desc;
 		break;
 	case ICH_V6_GPIO:
 		ichx_priv.desc = &ich6_desc;
 		break;
 	case ICH_V7_GPIO:
 		ichx_priv.desc = &ich7_desc;
 		break;
 	case ICH_V9_GPIO:
 		ichx_priv.desc = &ich9_desc;
 		break;
 	case ICH_V10CORP_GPIO:
 		ichx_priv.desc = &ich10_corp_desc;
 		break;
 	case ICH_V10CONS_GPIO:
 		ichx_priv.desc = &ich10_cons_desc;
 		break;
 	default:
 		return -ENODEV;
 	}

 	spin_lock_init(&ichx_priv.lock);
 	res_base = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPIO);
 	ichx_priv.use_gpio = ich_info->use_gpio;
 	err = ichx_gpio_request_regions(res_base, pdev->name,
 					ichx_priv.use_gpio);
 	if (err)
 		return err;

 	ichx_priv.gpio_base = res_base;

 	/*
 	 * If necessary, determine the I/O address of ACPI/power management
 	 * registers which are needed to read the the GPE0 register for GPI pins
 	 * 0 - 15 on some chipsets.
 	 */
 	if (!ichx_priv.desc->uses_gpe0)
 		goto init;

 	res_pm = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPE0);
 	if (!res_pm) {
 		pr_warn("ACPI BAR is unavailable, GPI 0 - 15 unavailable\n");
 		goto init;
 	}

 	if (!request_region(res_pm->start, resource_size(res_pm),
 			pdev->name)) {
 		pr_warn("ACPI BAR is busy, GPI 0 - 15 unavailable\n");
 		goto init;
 	}

 	ichx_priv.pm_base = res_pm;

 init:
 	ichx_gpiolib_setup(&ichx_priv.chip);
 	err = gpiochip_add(&ichx_priv.chip);
 	if (err) {
 		pr_err("Failed to register GPIOs\n");
 		goto add_err;
 	}

 	pr_info("GPIO from %d to %d on %s\n", ichx_priv.chip.base,
 	       ichx_priv.chip.base + ichx_priv.chip.ngpio - 1, DRV_NAME);

 	return 0;

 add_err:
 	ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
 	if (ichx_priv.pm_base)
 		release_region(ichx_priv.pm_base->start,
 				resource_size(ichx_priv.pm_base));
 	return err;
 }

 static int ichx_gpio_remove(struct platform_device *pdev)
 {
 	int err;

 	err = gpiochip_remove(&ichx_priv.chip);
 	if (err) {
 		dev_err(&pdev->dev, "%s failed, %d\n",
 				"gpiochip_remove()", err);
 		return err;
 	}

 	ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
 	if (ichx_priv.pm_base)
 		release_region(ichx_priv.pm_base->start,
 				resource_size(ichx_priv.pm_base));

 	return 0;
 }

 static struct platform_driver ichx_gpio_driver = {
 	.driver		= {
 		.owner	= THIS_MODULE,
 		.name	= DRV_NAME,
 	},
 	.probe		= ichx_gpio_probe,
 	.remove		= ichx_gpio_remove,
 };

 module_platform_driver(ichx_gpio_driver);

 MODULE_AUTHOR("Peter Tyser <ptyser@xes-inc.com>");
 MODULE_DESCRIPTION("GPIO interface for Intel ICH series");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:"DRV_NAME);
	/*
	* Intel ICH6-10, Series 5 and 6 GPIO driver
	*
	* Copyright (C) 2010 Extreme Engineering Solutions.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* 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.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/gpio.h>
	#include <linux/platform_device.h>
	#include <linux/mfd/lpc_ich.h>

	#define DRV_NAME "gpio_ich"

	/*
	* GPIO register offsets in GPIO I/O space.
	* Each chunk of 32 GPIOs is manipulated via its own USE_SELx, IO_SELx, and
	* LVLx registers. Logic in the read/write functions takes a register and
	* an absolute bit number and determines the proper register offset and bit
	* number in that register. For example, to read the value of GPIO bit 50
	* the code would access offset ichx_regs[2(=GPIO_LVL)][1(=50/32)],
	* bit 18 (50%32).
	*/
	enum GPIO_REG {
	GPIO_USE_SEL = 0,
	GPIO_IO_SEL,
	GPIO_LVL,
	GPO_BLINK
	};

	static const u8 ichx_regs[4][3] = {
	{0x00, 0x30, 0x40}, /* USE_SEL[1-3] offsets */
	{0x04, 0x34, 0x44}, /* IO_SEL[1-3] offsets */
	{0x0c, 0x38, 0x48}, /* LVL[1-3] offsets */
	{0x18, 0x18, 0x18}, /* BLINK offset */
	};

	static const u8 ichx_reglen[3] = {
	0x30, 0x10, 0x10,
	};

	#define ICHX_WRITE(val, reg, base_res) outl(val, (reg) + (base_res)->start)
	#define ICHX_READ(reg, base_res) inl((reg) + (base_res)->start)

	struct ichx_desc {
	/* Max GPIO pins the chipset can have */
	uint ngpio;

	/* chipset registers */
	const u8 (*regs)[3];
	const u8 *reglen;

	/* GPO_BLINK is available on this chipset */
	bool have_blink;

	/* Whether the chipset has GPIO in GPE0_STS in the PM IO region */
	bool uses_gpe0;

	/* USE_SEL is bogus on some chipsets, eg 3100 */
	u32 use_sel_ignore[3];

	/* Some chipsets have quirks, let these use their own request/get */
	int (request)(struct gpio_chip chip, unsigned offset);
	int (get)(struct gpio_chip chip, unsigned offset);

	/*
	* Some chipsets don't let reading output values on GPIO_LVL register
	* this option allows driver caching written output values
	*/
	bool use_outlvl_cache;
	};

	static struct {
	spinlock_t lock;
	struct platform_device *dev;
	struct gpio_chip chip;
	struct resource gpio_base; / GPIO IO base */
	struct resource pm_base; / Power Mangagment IO base */
	struct ichx_desc desc; / Pointer to chipset-specific description */
	u32 orig_gpio_ctrl; /* Orig CTRL value, used to restore on exit */
	u8 use_gpio; /* Which GPIO groups are usable */
	int outlvl_cache[3]; /* cached output values */
	} ichx_priv;

	static int modparam_gpiobase = -1; /* dynamic */
	module_param_named(gpiobase, modparam_gpiobase, int, 0444);
	MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, "
	"which is the default.");

	static int ichx_write_bit(int reg, unsigned nr, int val, int verify)
	{
	unsigned long flags;
	u32 data, tmp;
	int reg_nr = nr / 32;
	int bit = nr & 0x1f;
	int ret = 0;

	spin_lock_irqsave(&ichx_priv.lock, flags);

	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
	data = ichx_priv.outlvl_cache[reg_nr];
	else
	data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
	ichx_priv.gpio_base);

	if (val)
	data \|= 1 << bit;
	else
	data &= ~(1 << bit);
	ICHX_WRITE(data, ichx_priv.desc->regs[reg][reg_nr],
	ichx_priv.gpio_base);
	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
	ichx_priv.outlvl_cache[reg_nr] = data;

	tmp = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
	ichx_priv.gpio_base);
	if (verify && data != tmp)
	ret = -EPERM;

	spin_unlock_irqrestore(&ichx_priv.lock, flags);

	return ret;
	}

	static int ichx_read_bit(int reg, unsigned nr)
	{
	unsigned long flags;
	u32 data;
	int reg_nr = nr / 32;
	int bit = nr & 0x1f;

	spin_lock_irqsave(&ichx_priv.lock, flags);

	data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr],
	ichx_priv.gpio_base);

	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
	data = ichx_priv.outlvl_cache[reg_nr] \| data;

	spin_unlock_irqrestore(&ichx_priv.lock, flags);

	return data & (1 << bit) ? 1 : 0;
	}

	static bool ichx_gpio_check_available(struct gpio_chip *gpio, unsigned nr)
	{
	return !!(ichx_priv.use_gpio & (1 << (nr / 32)));
	}

	static int ichx_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
	{
	/*
	* Try setting pin as an input and verify it worked since many pins
	* are output-only.
	*/
	if (ichx_write_bit(GPIO_IO_SEL, nr, 1, 1))
	return -EINVAL;

	return 0;
	}

	static int ichx_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
	int val)
	{
	/* Disable blink hardware which is available for GPIOs from 0 to 31. */
	if (nr < 32 && ichx_priv.desc->have_blink)
	ichx_write_bit(GPO_BLINK, nr, 0, 0);

	/* Set GPIO output value. */
	ichx_write_bit(GPIO_LVL, nr, val, 0);

	/*
	* Try setting pin as an output and verify it worked since many pins
	* are input-only.
	*/
	if (ichx_write_bit(GPIO_IO_SEL, nr, 0, 1))
	return -EINVAL;

	return 0;
	}

	static int ichx_gpio_get(struct gpio_chip *chip, unsigned nr)
	{
	return ichx_read_bit(GPIO_LVL, nr);
	}

	static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr)
	{
	unsigned long flags;
	u32 data;

	/*
	* GPI 0 - 15 need to be read from the power management registers on
	* a ICH6/3100 bridge.
	*/
	if (nr < 16) {
	if (!ichx_priv.pm_base)
	return -ENXIO;

	spin_lock_irqsave(&ichx_priv.lock, flags);

	/* GPI 0 - 15 are latched, write 1 to clear*/
	ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base);
	data = ICHX_READ(0, ichx_priv.pm_base);

	spin_unlock_irqrestore(&ichx_priv.lock, flags);

	return (data >> 16) & (1 << nr) ? 1 : 0;
	} else {
	return ichx_gpio_get(chip, nr);
	}
	}

	static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr)
	{
	if (!ichx_gpio_check_available(chip, nr))
	return -ENXIO;

	/*
	* Note we assume the BIOS properly set a bridge's USE value. Some
	* chips (eg Intel 3100) have bogus USE values though, so first see if
	* the chipset's USE value can be trusted for this specific bit.
	* If it can't be trusted, assume that the pin can be used as a GPIO.
	*/
	if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f)))
	return 0;

	return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV;
	}

	static int ich6_gpio_request(struct gpio_chip *chip, unsigned nr)
	{
	/*
	* Fixups for bits 16 and 17 are necessary on the Intel ICH6/3100
	* bridge as they are controlled by USE register bits 0 and 1. See
	* "Table 704 GPIO_USE_SEL1 register" in the i3100 datasheet for
	* additional info.
	*/
	if (nr == 16 \|\| nr == 17)
	nr -= 16;

	return ichx_gpio_request(chip, nr);
	}

	static void ichx_gpio_set(struct gpio_chip *chip, unsigned nr, int val)
	{
	ichx_write_bit(GPIO_LVL, nr, val, 0);
	}

	static void ichx_gpiolib_setup(struct gpio_chip *chip)
	{
	chip->owner = THIS_MODULE;
	chip->label = DRV_NAME;
	chip->dev = &ichx_priv.dev->dev;

	/* Allow chip-specific overrides of request()/get() */
	chip->request = ichx_priv.desc->request ?
	ichx_priv.desc->request : ichx_gpio_request;
	chip->get = ichx_priv.desc->get ?
	ichx_priv.desc->get : ichx_gpio_get;

	chip->set = ichx_gpio_set;
	chip->direction_input = ichx_gpio_direction_input;
	chip->direction_output = ichx_gpio_direction_output;
	chip->base = modparam_gpiobase;
	chip->ngpio = ichx_priv.desc->ngpio;
	chip->can_sleep = false;
	chip->dbg_show = NULL;
	}

	/* ICH6-based, 631xesb-based */
	static struct ichx_desc ich6_desc = {
	/* Bridges using the ICH6 controller need fixups for GPIO 0 - 17 */
	.request = ich6_gpio_request,
	.get = ich6_gpio_get,

	/* GPIO 0-15 are read in the GPE0_STS PM register */
	.uses_gpe0 = true,

	.ngpio = 50,
	.have_blink = true,
	};

	/* Intel 3100 */
	static struct ichx_desc i3100_desc = {
	/*
	* Bits 16,17, 20 of USE_SEL and bit 16 of USE_SEL2 always read 0 on
	* the Intel 3100. See "Table 712. GPIO Summary Table" of 3100
	* Datasheet for more info.
	*/
	.use_sel_ignore = {0x00130000, 0x00010000, 0x0},

	/* The 3100 needs fixups for GPIO 0 - 17 */
	.request = ich6_gpio_request,
	.get = ich6_gpio_get,

	/* GPIO 0-15 are read in the GPE0_STS PM register */
	.uses_gpe0 = true,

	.ngpio = 50,
	};

	/* ICH7 and ICH8-based */
	static struct ichx_desc ich7_desc = {
	.ngpio = 50,
	.have_blink = true,
	.regs = ichx_regs,
	.reglen = ichx_reglen,
	};

	/* ICH9-based */
	static struct ichx_desc ich9_desc = {
	.ngpio = 61,
	.have_blink = true,
	.regs = ichx_regs,
	.reglen = ichx_reglen,
	};

	/* ICH10-based - Consumer/corporate versions have different amount of GPIO */
	static struct ichx_desc ich10_cons_desc = {
	.ngpio = 61,
	.have_blink = true,
	.regs = ichx_regs,
	.reglen = ichx_reglen,
	};
	static struct ichx_desc ich10_corp_desc = {
	.ngpio = 72,
	.have_blink = true,
	.regs = ichx_regs,
	.reglen = ichx_reglen,
	};

	/* Intel 5 series, 6 series, 3400 series, and C200 series */
	static struct ichx_desc intel5_desc = {
	.ngpio = 76,
	.regs = ichx_regs,
	.reglen = ichx_reglen,
	};

	static int ichx_gpio_request_regions(struct resource *res_base,
	const char *name, u8 use_gpio)
	{
	int i;

	if (!res_base \|\| !res_base->start \|\| !res_base->end)
	return -ENODEV;

	for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) {
	if (!(use_gpio & (1 << i)))
	continue;
	if (!request_region(
	res_base->start + ichx_priv.desc->regs[0][i],
	ichx_priv.desc->reglen[i], name))
	goto request_err;
	}
	return 0;

	request_err:
	/* Clean up: release already requested regions, if any */
	for (i--; i >= 0; i--) {
	if (!(use_gpio & (1 << i)))
	continue;
	release_region(res_base->start + ichx_priv.desc->regs[0][i],
	ichx_priv.desc->reglen[i]);
	}
	return -EBUSY;
	}

	static void ichx_gpio_release_regions(struct resource *res_base, u8 use_gpio)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) {
	if (!(use_gpio & (1 << i)))
	continue;
	release_region(res_base->start + ichx_priv.desc->regs[0][i],
	ichx_priv.desc->reglen[i]);
	}
	}

	static int ichx_gpio_probe(struct platform_device *pdev)
	{
	struct resource res_base, res_pm;
	int err;
	struct lpc_ich_info *ich_info = dev_get_platdata(&pdev->dev);

	if (!ich_info)
	return -ENODEV;

	ichx_priv.dev = pdev;

	switch (ich_info->gpio_version) {
	case ICH_I3100_GPIO:
	ichx_priv.desc = &i3100_desc;
	break;
	case ICH_V5_GPIO:
	ichx_priv.desc = &intel5_desc;
	break;
	case ICH_V6_GPIO:
	ichx_priv.desc = &ich6_desc;
	break;
	case ICH_V7_GPIO:
	ichx_priv.desc = &ich7_desc;
	break;
	case ICH_V9_GPIO:
	ichx_priv.desc = &ich9_desc;
	break;
	case ICH_V10CORP_GPIO:
	ichx_priv.desc = &ich10_corp_desc;
	break;
	case ICH_V10CONS_GPIO:
	ichx_priv.desc = &ich10_cons_desc;
	break;
	default:
	return -ENODEV;
	}

	spin_lock_init(&ichx_priv.lock);
	res_base = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPIO);
	ichx_priv.use_gpio = ich_info->use_gpio;
	err = ichx_gpio_request_regions(res_base, pdev->name,
	ichx_priv.use_gpio);
	if (err)
	return err;

	ichx_priv.gpio_base = res_base;

	/*
	* If necessary, determine the I/O address of ACPI/power management
	* registers which are needed to read the the GPE0 register for GPI pins
	* 0 - 15 on some chipsets.
	*/
	if (!ichx_priv.desc->uses_gpe0)
	goto init;

	res_pm = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPE0);
	if (!res_pm) {
	pr_warn("ACPI BAR is unavailable, GPI 0 - 15 unavailable\n");
	goto init;
	}

	if (!request_region(res_pm->start, resource_size(res_pm),
	pdev->name)) {
	pr_warn("ACPI BAR is busy, GPI 0 - 15 unavailable\n");
	goto init;
	}

	ichx_priv.pm_base = res_pm;

	init:
	ichx_gpiolib_setup(&ichx_priv.chip);
	err = gpiochip_add(&ichx_priv.chip);
	if (err) {
	pr_err("Failed to register GPIOs\n");
	goto add_err;
	}

	pr_info("GPIO from %d to %d on %s\n", ichx_priv.chip.base,
	ichx_priv.chip.base + ichx_priv.chip.ngpio - 1, DRV_NAME);

	return 0;

	add_err:
	ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
	if (ichx_priv.pm_base)
	release_region(ichx_priv.pm_base->start,
	resource_size(ichx_priv.pm_base));
	return err;
	}

	static int ichx_gpio_remove(struct platform_device *pdev)
	{
	int err;

	err = gpiochip_remove(&ichx_priv.chip);
	if (err) {
	dev_err(&pdev->dev, "%s failed, %d\n",
	"gpiochip_remove()", err);
	return err;
	}

	ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
	if (ichx_priv.pm_base)
	release_region(ichx_priv.pm_base->start,
	resource_size(ichx_priv.pm_base));

	return 0;
	}

	static struct platform_driver ichx_gpio_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = DRV_NAME,
	},
	.probe = ichx_gpio_probe,
	.remove = ichx_gpio_remove,
	};

	module_platform_driver(ichx_gpio_driver);

	MODULE_AUTHOR("Peter Tyser <ptyser@xes-inc.com>");
	MODULE_DESCRIPTION("GPIO interface for Intel ICH series");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:"DRV_NAME);