xref: /linux/drivers/pinctrl/intel/pinctrl-lynxpoint.c (revision 64e14e90646cafa9940cead9f7ba336c55671bf9)

// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO controller driver for Intel Lynxpoint PCH chipset>
 * Copyright (c) 2012, Intel Corporation.
 *
 * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
 */

#include <linux/acpi.h>
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinconf-generic.h>

#include "pinctrl-intel.h"

#define COMMUNITY(p, n)			\
	{				\
		.pin_base	= (p),	\
		.npins		= (n),	\
	}

static const struct pinctrl_pin_desc lptlp_pins[] = {
	PINCTRL_PIN(0, "GP0_UART1_RXD"),
	PINCTRL_PIN(1, "GP1_UART1_TXD"),
	PINCTRL_PIN(2, "GP2_UART1_RTSB"),
	PINCTRL_PIN(3, "GP3_UART1_CTSB"),
	PINCTRL_PIN(4, "GP4_I2C0_SDA"),
	PINCTRL_PIN(5, "GP5_I2C0_SCL"),
	PINCTRL_PIN(6, "GP6_I2C1_SDA"),
	PINCTRL_PIN(7, "GP7_I2C1_SCL"),
	PINCTRL_PIN(8, "GP8"),
	PINCTRL_PIN(9, "GP9"),
	PINCTRL_PIN(10, "GP10"),
	PINCTRL_PIN(11, "GP11_SMBALERTB"),
	PINCTRL_PIN(12, "GP12_LANPHYPC"),
	PINCTRL_PIN(13, "GP13"),
	PINCTRL_PIN(14, "GP14"),
	PINCTRL_PIN(15, "GP15"),
	PINCTRL_PIN(16, "GP16_MGPIO9"),
	PINCTRL_PIN(17, "GP17_MGPIO10"),
	PINCTRL_PIN(18, "GP18_SRC0CLKRQB"),
	PINCTRL_PIN(19, "GP19_SRC1CLKRQB"),
	PINCTRL_PIN(20, "GP20_SRC2CLKRQB"),
	PINCTRL_PIN(21, "GP21_SRC3CLKRQB"),
	PINCTRL_PIN(22, "GP22_SRC4CLKRQB_TRST2"),
	PINCTRL_PIN(23, "GP23_SRC5CLKRQB_TDI2"),
	PINCTRL_PIN(24, "GP24_MGPIO0"),
	PINCTRL_PIN(25, "GP25_USBWAKEOUTB"),
	PINCTRL_PIN(26, "GP26_MGPIO5"),
	PINCTRL_PIN(27, "GP27_MGPIO6"),
	PINCTRL_PIN(28, "GP28_MGPIO7"),
	PINCTRL_PIN(29, "GP29_SLP_WLANB_MGPIO3"),
	PINCTRL_PIN(30, "GP30_SUSWARNB_SUSPWRDNACK_MGPIO1"),
	PINCTRL_PIN(31, "GP31_ACPRESENT_MGPIO2"),
	PINCTRL_PIN(32, "GP32_CLKRUNB"),
	PINCTRL_PIN(33, "GP33_DEVSLP0"),
	PINCTRL_PIN(34, "GP34_SATA0XPCIE6L3B_SATA0GP"),
	PINCTRL_PIN(35, "GP35_SATA1XPCIE6L2B_SATA1GP"),
	PINCTRL_PIN(36, "GP36_SATA2XPCIE6L1B_SATA2GP"),
	PINCTRL_PIN(37, "GP37_SATA3XPCIE6L0B_SATA3GP"),
	PINCTRL_PIN(38, "GP38_DEVSLP1"),
	PINCTRL_PIN(39, "GP39_DEVSLP2"),
	PINCTRL_PIN(40, "GP40_OC0B"),
	PINCTRL_PIN(41, "GP41_OC1B"),
	PINCTRL_PIN(42, "GP42_OC2B"),
	PINCTRL_PIN(43, "GP43_OC3B"),
	PINCTRL_PIN(44, "GP44"),
	PINCTRL_PIN(45, "GP45_TMS2"),
	PINCTRL_PIN(46, "GP46_TDO2"),
	PINCTRL_PIN(47, "GP47"),
	PINCTRL_PIN(48, "GP48"),
	PINCTRL_PIN(49, "GP49"),
	PINCTRL_PIN(50, "GP50"),
	PINCTRL_PIN(51, "GP51_GSXDOUT"),
	PINCTRL_PIN(52, "GP52_GSXSLOAD"),
	PINCTRL_PIN(53, "GP53_GSXDIN"),
	PINCTRL_PIN(54, "GP54_GSXSRESETB"),
	PINCTRL_PIN(55, "GP55_GSXCLK"),
	PINCTRL_PIN(56, "GP56"),
	PINCTRL_PIN(57, "GP57"),
	PINCTRL_PIN(58, "GP58"),
	PINCTRL_PIN(59, "GP59"),
	PINCTRL_PIN(60, "GP60_SML0ALERTB_MGPIO4"),
	PINCTRL_PIN(61, "GP61_SUS_STATB"),
	PINCTRL_PIN(62, "GP62_SUSCLK"),
	PINCTRL_PIN(63, "GP63_SLP_S5B"),
	PINCTRL_PIN(64, "GP64_SDIO_CLK"),
	PINCTRL_PIN(65, "GP65_SDIO_CMD"),
	PINCTRL_PIN(66, "GP66_SDIO_D0"),
	PINCTRL_PIN(67, "GP67_SDIO_D1"),
	PINCTRL_PIN(68, "GP68_SDIO_D2"),
	PINCTRL_PIN(69, "GP69_SDIO_D3"),
	PINCTRL_PIN(70, "GP70_SDIO_POWER_EN"),
	PINCTRL_PIN(71, "GP71_MPHYPC"),
	PINCTRL_PIN(72, "GP72_BATLOWB"),
	PINCTRL_PIN(73, "GP73_SML1ALERTB_PCHHOTB_MGPIO8"),
	PINCTRL_PIN(74, "GP74_SML1DATA_MGPIO12"),
	PINCTRL_PIN(75, "GP75_SML1CLK_MGPIO11"),
	PINCTRL_PIN(76, "GP76_BMBUSYB"),
	PINCTRL_PIN(77, "GP77_PIRQAB"),
	PINCTRL_PIN(78, "GP78_PIRQBB"),
	PINCTRL_PIN(79, "GP79_PIRQCB"),
	PINCTRL_PIN(80, "GP80_PIRQDB"),
	PINCTRL_PIN(81, "GP81_SPKR"),
	PINCTRL_PIN(82, "GP82_RCINB"),
	PINCTRL_PIN(83, "GP83_GSPI0_CSB"),
	PINCTRL_PIN(84, "GP84_GSPI0_CLK"),
	PINCTRL_PIN(85, "GP85_GSPI0_MISO"),
	PINCTRL_PIN(86, "GP86_GSPI0_MOSI"),
	PINCTRL_PIN(87, "GP87_GSPI1_CSB"),
	PINCTRL_PIN(88, "GP88_GSPI1_CLK"),
	PINCTRL_PIN(89, "GP89_GSPI1_MISO"),
	PINCTRL_PIN(90, "GP90_GSPI1_MOSI"),
	PINCTRL_PIN(91, "GP91_UART0_RXD"),
	PINCTRL_PIN(92, "GP92_UART0_TXD"),
	PINCTRL_PIN(93, "GP93_UART0_RTSB"),
	PINCTRL_PIN(94, "GP94_UART0_CTSB"),
};

static const struct intel_community lptlp_communities[] = {
	COMMUNITY(0, 95),
};

static const struct intel_pinctrl_soc_data lptlp_soc_data = {
	.pins		= lptlp_pins,
	.npins		= ARRAY_SIZE(lptlp_pins),
	.communities	= lptlp_communities,
	.ncommunities	= ARRAY_SIZE(lptlp_communities),
};

/* LynxPoint chipset has support for 95 GPIO pins */

#define LP_NUM_GPIO	95

/* Bitmapped register offsets */
#define LP_ACPI_OWNED	0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */
#define LP_IRQ2IOXAPIC	0x10 /* Bitmap, set by bios, 1: pin routed to IOxAPIC */
#define LP_GC		0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */
#define LP_INT_STAT	0x80
#define LP_INT_ENABLE	0x90

/* Each pin has two 32 bit config registers, starting at 0x100 */
#define LP_CONFIG1	0x100
#define LP_CONFIG2	0x104

/* LP_CONFIG1 reg bits */
#define OUT_LVL_BIT	BIT(31)
#define IN_LVL_BIT	BIT(30)
#define TRIG_SEL_BIT	BIT(4) /* 0: Edge, 1: Level */
#define INT_INV_BIT	BIT(3) /* Invert interrupt triggering */
#define DIR_BIT		BIT(2) /* 0: Output, 1: Input */
#define USE_SEL_MASK	GENMASK(1, 0)	/* 0: Native, 1: GPIO, ... */
#define USE_SEL_NATIVE	(0 << 0)
#define USE_SEL_GPIO	(1 << 0)

/* LP_CONFIG2 reg bits */
#define GPINDIS_BIT	BIT(2) /* disable input sensing */
#define GPIWP_MASK	GENMASK(1, 0)	/* weak pull options */
#define GPIWP_NONE	0		/* none */
#define GPIWP_DOWN	1		/* weak pull down */
#define GPIWP_UP	2		/* weak pull up */

/*
 * Lynxpoint gpios are controlled through both bitmapped registers and
 * per gpio specific registers. The bitmapped registers are in chunks of
 * 3 x 32bit registers to cover all 95 GPIOs
 *
 * per gpio specific registers consist of two 32bit registers per gpio
 * (LP_CONFIG1 and LP_CONFIG2), with 95 GPIOs there's a total of
 * 190 config registers.
 *
 * A simplified view of the register layout look like this:
 *
 * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31  (bitmapped registers)
 * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63
 * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94
 * ...
 * LP_INT_ENABLE[31:0] ...
 * LP_INT_ENABLE[63:32] ...
 * LP_INT_ENABLE[94:64] ...
 * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers)
 * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0
 * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1
 * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1
 * LP2_CONFIG1 (gpio 2) ...
 * LP2_CONFIG2 (gpio 2) ...
 * ...
 * LP94_CONFIG1 (gpio 94) ...
 * LP94_CONFIG2 (gpio 94) ...
 *
 * IOxAPIC redirection map applies only for gpio 8-10, 13-14, 45-55.
 */

static struct intel_community *lp_get_community(struct intel_pinctrl *lg,
						unsigned int pin)
{
	struct intel_community *comm;
	int i;

	for (i = 0; i < lg->ncommunities; i++) {
		comm = &lg->communities[i];
		if (pin < comm->pin_base + comm->npins && pin >= comm->pin_base)
			return comm;
	}

	return NULL;
}

static void __iomem *lp_gpio_reg(struct gpio_chip *chip, unsigned int offset,
				 int reg)
{
	struct intel_pinctrl *lg = gpiochip_get_data(chip);
	struct intel_community *comm;
	int reg_offset;

	comm = lp_get_community(lg, offset);
	if (!comm)
		return NULL;

	offset -= comm->pin_base;

	if (reg == LP_CONFIG1 || reg == LP_CONFIG2)
		/* per gpio specific config registers */
		reg_offset = offset * 8;
	else
		/* bitmapped registers */
		reg_offset = (offset / 32) * 4;

	return comm->regs + reg_offset + reg;
}

static bool lp_gpio_acpi_use(struct intel_pinctrl *lg, unsigned int pin)
{
	void __iomem *acpi_use;

	acpi_use = lp_gpio_reg(&lg->chip, pin, LP_ACPI_OWNED);
	if (!acpi_use)
		return true;

	return !(ioread32(acpi_use) & BIT(pin % 32));
}

static bool lp_gpio_ioxapic_use(struct gpio_chip *chip, unsigned int offset)
{
	void __iomem *ioxapic_use = lp_gpio_reg(chip, offset, LP_IRQ2IOXAPIC);
	u32 value;

	value = ioread32(ioxapic_use);

	if (offset >= 8 && offset <= 10)
		return !!(value & BIT(offset -  8 + 0));
	if (offset >= 13 && offset <= 14)
		return !!(value & BIT(offset - 13 + 3));
	if (offset >= 45 && offset <= 55)
		return !!(value & BIT(offset - 45 + 5));

	return false;
}

static int lp_get_groups_count(struct pinctrl_dev *pctldev)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	return lg->soc->ngroups;
}

static const char *lp_get_group_name(struct pinctrl_dev *pctldev,
				     unsigned int selector)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	return lg->soc->groups[selector].name;
}

static int lp_get_group_pins(struct pinctrl_dev *pctldev,
			     unsigned int selector,
			     const unsigned int **pins,
			     unsigned int *num_pins)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	*pins		= lg->soc->groups[selector].pins;
	*num_pins	= lg->soc->groups[selector].npins;

	return 0;
}

static void lp_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
			    unsigned int pin)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *reg = lp_gpio_reg(&lg->chip, pin, LP_CONFIG1);
	void __iomem *conf2 = lp_gpio_reg(&lg->chip, pin, LP_CONFIG2);
	u32 value, mode;

	value = ioread32(reg);

	mode = value & USE_SEL_MASK;
	if (mode == USE_SEL_GPIO)
		seq_puts(s, "GPIO ");
	else
		seq_printf(s, "mode %d ", mode);

	seq_printf(s, "0x%08x 0x%08x", value, ioread32(conf2));

	if (lp_gpio_acpi_use(lg, pin))
		seq_puts(s, " [ACPI]");
}

static const struct pinctrl_ops lptlp_pinctrl_ops = {
	.get_groups_count	= lp_get_groups_count,
	.get_group_name		= lp_get_group_name,
	.get_group_pins		= lp_get_group_pins,
	.pin_dbg_show		= lp_pin_dbg_show,
};

static int lp_get_functions_count(struct pinctrl_dev *pctldev)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	return lg->soc->nfunctions;
}

static const char *lp_get_function_name(struct pinctrl_dev *pctldev,
					unsigned int selector)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	return lg->soc->functions[selector].name;
}

static int lp_get_function_groups(struct pinctrl_dev *pctldev,
				  unsigned int selector,
				  const char * const **groups,
				  unsigned int *num_groups)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);

	*groups		= lg->soc->functions[selector].groups;
	*num_groups	= lg->soc->functions[selector].ngroups;

	return 0;
}

static int lp_pinmux_set_mux(struct pinctrl_dev *pctldev,
			     unsigned int function, unsigned int group)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	const struct intel_pingroup *grp = &lg->soc->groups[group];
	unsigned long flags;
	int i;

	raw_spin_lock_irqsave(&lg->lock, flags);

	/* Now enable the mux setting for each pin in the group */
	for (i = 0; i < grp->npins; i++) {
		void __iomem *reg = lp_gpio_reg(&lg->chip, grp->pins[i], LP_CONFIG1);
		u32 value;

		value = ioread32(reg);

		value &= ~USE_SEL_MASK;
		if (grp->modes)
			value |= grp->modes[i];
		else
			value |= grp->mode;

		iowrite32(value, reg);
	}

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	return 0;
}

static int lp_gpio_request_enable(struct pinctrl_dev *pctldev,
				  struct pinctrl_gpio_range *range,
				  unsigned int pin)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *reg = lp_gpio_reg(&lg->chip, pin, LP_CONFIG1);
	void __iomem *conf2 = lp_gpio_reg(&lg->chip, pin, LP_CONFIG2);
	unsigned long flags;
	u32 value;

	pm_runtime_get(lg->dev);

	raw_spin_lock_irqsave(&lg->lock, flags);

	/*
	 * Reconfigure pin to GPIO mode if needed and issue a warning,
	 * since we expect firmware to configure it properly.
	 */
	value = ioread32(reg);
	if ((value & USE_SEL_MASK) != USE_SEL_GPIO) {
		iowrite32((value & USE_SEL_MASK) | USE_SEL_GPIO, reg);
		dev_warn(lg->dev, FW_BUG "pin %u forcibly reconfigured as GPIO\n", pin);
	}

	/* Enable input sensing */
	iowrite32(ioread32(conf2) & ~GPINDIS_BIT, conf2);

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	return 0;
}

static void lp_gpio_disable_free(struct pinctrl_dev *pctldev,
				 struct pinctrl_gpio_range *range,
				 unsigned int pin)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *conf2 = lp_gpio_reg(&lg->chip, pin, LP_CONFIG2);
	unsigned long flags;

	raw_spin_lock_irqsave(&lg->lock, flags);

	/* Disable input sensing */
	iowrite32(ioread32(conf2) | GPINDIS_BIT, conf2);

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	pm_runtime_put(lg->dev);
}

static int lp_gpio_set_direction(struct pinctrl_dev *pctldev,
				 struct pinctrl_gpio_range *range,
				 unsigned int pin, bool input)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *reg = lp_gpio_reg(&lg->chip, pin, LP_CONFIG1);
	unsigned long flags;
	u32 value;

	raw_spin_lock_irqsave(&lg->lock, flags);

	value = ioread32(reg);
	value &= ~DIR_BIT;
	if (input) {
		value |= DIR_BIT;
	} else {
		/*
		 * Before making any direction modifications, do a check if GPIO
		 * is set for direct IRQ. On Lynxpoint, setting GPIO to output
		 * does not make sense, so let's at least warn the caller before
		 * they shoot themselves in the foot.
		 */
		WARN(lp_gpio_ioxapic_use(&lg->chip, pin),
		     "Potential Error: Setting GPIO to output with IOxAPIC redirection");
	}
	iowrite32(value, reg);

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	return 0;
}

static const struct pinmux_ops lptlp_pinmux_ops = {
	.get_functions_count	= lp_get_functions_count,
	.get_function_name	= lp_get_function_name,
	.get_function_groups	= lp_get_function_groups,
	.set_mux		= lp_pinmux_set_mux,
	.gpio_request_enable	= lp_gpio_request_enable,
	.gpio_disable_free	= lp_gpio_disable_free,
	.gpio_set_direction	= lp_gpio_set_direction,
};

static int lp_pin_config_get(struct pinctrl_dev *pctldev, unsigned int pin,
			     unsigned long *config)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *conf2 = lp_gpio_reg(&lg->chip, pin, LP_CONFIG2);
	enum pin_config_param param = pinconf_to_config_param(*config);
	unsigned long flags;
	u32 value, pull;
	u16 arg = 0;

	raw_spin_lock_irqsave(&lg->lock, flags);
	value = ioread32(conf2);
	raw_spin_unlock_irqrestore(&lg->lock, flags);

	pull = value & GPIWP_MASK;

	switch (param) {
	case PIN_CONFIG_BIAS_DISABLE:
		if (pull)
			return -EINVAL;
		break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
		if (pull != GPIWP_DOWN)
			return -EINVAL;

		arg = 1;
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		if (pull != GPIWP_UP)
			return -EINVAL;

		arg = 1;
		break;
	default:
		return -ENOTSUPP;
	}

	*config = pinconf_to_config_packed(param, arg);

	return 0;
}

static int lp_pin_config_set(struct pinctrl_dev *pctldev, unsigned int pin,
			     unsigned long *configs, unsigned int num_configs)
{
	struct intel_pinctrl *lg = pinctrl_dev_get_drvdata(pctldev);
	void __iomem *conf2 = lp_gpio_reg(&lg->chip, pin, LP_CONFIG2);
	enum pin_config_param param;
	unsigned long flags;
	int i, ret = 0;
	u32 value;

	raw_spin_lock_irqsave(&lg->lock, flags);

	value = ioread32(conf2);

	for (i = 0; i < num_configs; i++) {
		param = pinconf_to_config_param(configs[i]);

		switch (param) {
		case PIN_CONFIG_BIAS_DISABLE:
			value &= ~GPIWP_MASK;
			break;
		case PIN_CONFIG_BIAS_PULL_DOWN:
			value &= ~GPIWP_MASK;
			value |= GPIWP_DOWN;
			break;
		case PIN_CONFIG_BIAS_PULL_UP:
			value &= ~GPIWP_MASK;
			value |= GPIWP_UP;
			break;
		default:
			ret = -ENOTSUPP;
		}

		if (ret)
			break;
	}

	if (!ret)
		iowrite32(value, conf2);

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	return ret;
}

static const struct pinconf_ops lptlp_pinconf_ops = {
	.is_generic	= true,
	.pin_config_get	= lp_pin_config_get,
	.pin_config_set	= lp_pin_config_set,
};

static const struct pinctrl_desc lptlp_pinctrl_desc = {
	.pctlops	= &lptlp_pinctrl_ops,
	.pmxops		= &lptlp_pinmux_ops,
	.confops	= &lptlp_pinconf_ops,
	.owner		= THIS_MODULE,
};

static int lp_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	void __iomem *reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
	return !!(ioread32(reg) & IN_LVL_BIT);
}

static void lp_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
{
	struct intel_pinctrl *lg = gpiochip_get_data(chip);
	void __iomem *reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
	unsigned long flags;

	raw_spin_lock_irqsave(&lg->lock, flags);

	if (value)
		iowrite32(ioread32(reg) | OUT_LVL_BIT, reg);
	else
		iowrite32(ioread32(reg) & ~OUT_LVL_BIT, reg);

	raw_spin_unlock_irqrestore(&lg->lock, flags);
}

static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	return pinctrl_gpio_direction_input(chip->base + offset);
}

static int lp_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
				    int value)
{
	lp_gpio_set(chip, offset, value);

	return pinctrl_gpio_direction_output(chip->base + offset);
}

static int lp_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	void __iomem *reg = lp_gpio_reg(chip, offset, LP_CONFIG1);

	if (ioread32(reg) & DIR_BIT)
		return GPIO_LINE_DIRECTION_IN;

	return GPIO_LINE_DIRECTION_OUT;
}

static void lp_gpio_irq_handler(struct irq_desc *desc)
{
	struct irq_data *data = irq_desc_get_irq_data(desc);
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct intel_pinctrl *lg = gpiochip_get_data(gc);
	struct irq_chip *chip = irq_data_get_irq_chip(data);
	void __iomem *reg, *ena;
	unsigned long pending;
	u32 base, pin;

	/* check from GPIO controller which pin triggered the interrupt */
	for (base = 0; base < lg->chip.ngpio; base += 32) {
		reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
		ena = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);

		/* Only interrupts that are enabled */
		pending = ioread32(reg) & ioread32(ena);

		for_each_set_bit(pin, &pending, 32) {
			unsigned int irq;

			irq = irq_find_mapping(lg->chip.irq.domain, base + pin);
			generic_handle_irq(irq);
		}
	}
	chip->irq_eoi(data);
}

static void lp_irq_ack(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct intel_pinctrl *lg = gpiochip_get_data(gc);
	u32 hwirq = irqd_to_hwirq(d);
	void __iomem *reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_STAT);
	unsigned long flags;

	raw_spin_lock_irqsave(&lg->lock, flags);
	iowrite32(BIT(hwirq % 32), reg);
	raw_spin_unlock_irqrestore(&lg->lock, flags);
}

static void lp_irq_unmask(struct irq_data *d)
{
}

static void lp_irq_mask(struct irq_data *d)
{
}

static void lp_irq_enable(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct intel_pinctrl *lg = gpiochip_get_data(gc);
	u32 hwirq = irqd_to_hwirq(d);
	void __iomem *reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
	unsigned long flags;

	raw_spin_lock_irqsave(&lg->lock, flags);
	iowrite32(ioread32(reg) | BIT(hwirq % 32), reg);
	raw_spin_unlock_irqrestore(&lg->lock, flags);
}

static void lp_irq_disable(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct intel_pinctrl *lg = gpiochip_get_data(gc);
	u32 hwirq = irqd_to_hwirq(d);
	void __iomem *reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
	unsigned long flags;

	raw_spin_lock_irqsave(&lg->lock, flags);
	iowrite32(ioread32(reg) & ~BIT(hwirq % 32), reg);
	raw_spin_unlock_irqrestore(&lg->lock, flags);
}

static int lp_irq_set_type(struct irq_data *d, unsigned int type)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct intel_pinctrl *lg = gpiochip_get_data(gc);
	u32 hwirq = irqd_to_hwirq(d);
	void __iomem *reg = lp_gpio_reg(&lg->chip, hwirq, LP_CONFIG1);
	unsigned long flags;
	u32 value;

	if (hwirq >= lg->chip.ngpio)
		return -EINVAL;

	/* Fail if BIOS reserved pin for ACPI use */
	if (lp_gpio_acpi_use(lg, hwirq)) {
		dev_err(lg->dev, "pin %u can't be used as IRQ\n", hwirq);
		return -EBUSY;
	}

	raw_spin_lock_irqsave(&lg->lock, flags);
	value = ioread32(reg);

	/* set both TRIG_SEL and INV bits to 0 for rising edge */
	if (type & IRQ_TYPE_EDGE_RISING)
		value &= ~(TRIG_SEL_BIT | INT_INV_BIT);

	/* TRIG_SEL bit 0, INV bit 1 for falling edge */
	if (type & IRQ_TYPE_EDGE_FALLING)
		value = (value | INT_INV_BIT) & ~TRIG_SEL_BIT;

	/* TRIG_SEL bit 1, INV bit 0 for level low */
	if (type & IRQ_TYPE_LEVEL_LOW)
		value = (value | TRIG_SEL_BIT) & ~INT_INV_BIT;

	/* TRIG_SEL bit 1, INV bit 1 for level high */
	if (type & IRQ_TYPE_LEVEL_HIGH)
		value |= TRIG_SEL_BIT | INT_INV_BIT;

	iowrite32(value, reg);

	if (type & IRQ_TYPE_EDGE_BOTH)
		irq_set_handler_locked(d, handle_edge_irq);
	else if (type & IRQ_TYPE_LEVEL_MASK)
		irq_set_handler_locked(d, handle_level_irq);

	raw_spin_unlock_irqrestore(&lg->lock, flags);

	return 0;
}

static struct irq_chip lp_irqchip = {
	.name = "LP-GPIO",
	.irq_ack = lp_irq_ack,
	.irq_mask = lp_irq_mask,
	.irq_unmask = lp_irq_unmask,
	.irq_enable = lp_irq_enable,
	.irq_disable = lp_irq_disable,
	.irq_set_type = lp_irq_set_type,
	.flags = IRQCHIP_SKIP_SET_WAKE,
};

static int lp_gpio_irq_init_hw(struct gpio_chip *chip)
{
	struct intel_pinctrl *lg = gpiochip_get_data(chip);
	void __iomem *reg;
	unsigned int base;

	for (base = 0; base < lg->chip.ngpio; base += 32) {
		/* disable gpio pin interrupts */
		reg = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);
		iowrite32(0, reg);
		/* Clear interrupt status register */
		reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
		iowrite32(0xffffffff, reg);
	}

	return 0;
}

static int lp_gpio_add_pin_ranges(struct gpio_chip *chip)
{
	struct intel_pinctrl *lg = gpiochip_get_data(chip);
	struct device *dev = lg->dev;
	int ret;

	ret = gpiochip_add_pin_range(chip, dev_name(dev), 0, 0, lg->soc->npins);
	if (ret)
		dev_err(dev, "failed to add GPIO pin range\n");

	return ret;
}

static int lp_gpio_probe(struct platform_device *pdev)
{
	const struct intel_pinctrl_soc_data *soc;
	struct intel_pinctrl *lg;
	struct gpio_chip *gc;
	struct resource *io_rc, *irq_rc;
	struct device *dev = &pdev->dev;
	void __iomem *regs;
	unsigned int i;
	int ret;

	soc = (const struct intel_pinctrl_soc_data *)device_get_match_data(dev);
	if (!soc)
		return -ENODEV;

	lg = devm_kzalloc(dev, sizeof(*lg), GFP_KERNEL);
	if (!lg)
		return -ENOMEM;

	lg->dev = dev;
	lg->soc = soc;

	lg->ncommunities = lg->soc->ncommunities;
	lg->communities = devm_kcalloc(dev, lg->ncommunities,
				       sizeof(*lg->communities), GFP_KERNEL);
	if (!lg->communities)
		return -ENOMEM;

	lg->pctldesc           = lptlp_pinctrl_desc;
	lg->pctldesc.name      = dev_name(dev);
	lg->pctldesc.pins      = lg->soc->pins;
	lg->pctldesc.npins     = lg->soc->npins;

	lg->pctldev = devm_pinctrl_register(dev, &lg->pctldesc, lg);
	if (IS_ERR(lg->pctldev)) {
		dev_err(dev, "failed to register pinctrl driver\n");
		return PTR_ERR(lg->pctldev);
	}

	platform_set_drvdata(pdev, lg);

	io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!io_rc) {
		dev_err(dev, "missing IO resources\n");
		return -EINVAL;
	}

	regs = devm_ioport_map(dev, io_rc->start, resource_size(io_rc));
	if (!regs) {
		dev_err(dev, "failed mapping IO region %pR\n", &io_rc);
		return -EBUSY;
	}

	for (i = 0; i < lg->soc->ncommunities; i++) {
		struct intel_community *comm = &lg->communities[i];

		*comm = lg->soc->communities[i];

		comm->regs = regs;
		comm->pad_regs = regs + 0x100;
	}

	raw_spin_lock_init(&lg->lock);

	gc = &lg->chip;
	gc->label = dev_name(dev);
	gc->owner = THIS_MODULE;
	gc->request = gpiochip_generic_request;
	gc->free = gpiochip_generic_free;
	gc->direction_input = lp_gpio_direction_input;
	gc->direction_output = lp_gpio_direction_output;
	gc->get = lp_gpio_get;
	gc->set = lp_gpio_set;
	gc->get_direction = lp_gpio_get_direction;
	gc->base = -1;
	gc->ngpio = LP_NUM_GPIO;
	gc->can_sleep = false;
	gc->add_pin_ranges = lp_gpio_add_pin_ranges;
	gc->parent = dev;

	/* set up interrupts  */
	irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (irq_rc && irq_rc->start) {
		struct gpio_irq_chip *girq;

		girq = &gc->irq;
		girq->chip = &lp_irqchip;
		girq->init_hw = lp_gpio_irq_init_hw;
		girq->parent_handler = lp_gpio_irq_handler;
		girq->num_parents = 1;
		girq->parents = devm_kcalloc(dev, girq->num_parents,
					     sizeof(*girq->parents),
					     GFP_KERNEL);
		if (!girq->parents)
			return -ENOMEM;
		girq->parents[0] = (unsigned int)irq_rc->start;
		girq->default_type = IRQ_TYPE_NONE;
		girq->handler = handle_bad_irq;
	}

	ret = devm_gpiochip_add_data(dev, gc, lg);
	if (ret) {
		dev_err(dev, "failed adding lp-gpio chip\n");
		return ret;
	}

	pm_runtime_enable(dev);

	return 0;
}

static int lp_gpio_remove(struct platform_device *pdev)
{
	pm_runtime_disable(&pdev->dev);
	return 0;
}

static int lp_gpio_runtime_suspend(struct device *dev)
{
	return 0;
}

static int lp_gpio_runtime_resume(struct device *dev)
{
	return 0;
}

static int lp_gpio_resume(struct device *dev)
{
	struct intel_pinctrl *lg = dev_get_drvdata(dev);
	void __iomem *reg;
	int i;

	/* on some hardware suspend clears input sensing, re-enable it here */
	for (i = 0; i < lg->chip.ngpio; i++) {
		if (gpiochip_is_requested(&lg->chip, i) != NULL) {
			reg = lp_gpio_reg(&lg->chip, i, LP_CONFIG2);
			iowrite32(ioread32(reg) & ~GPINDIS_BIT, reg);
		}
	}
	return 0;
}

static const struct dev_pm_ops lp_gpio_pm_ops = {
	.runtime_suspend = lp_gpio_runtime_suspend,
	.runtime_resume = lp_gpio_runtime_resume,
	.resume = lp_gpio_resume,
};

static const struct acpi_device_id lynxpoint_gpio_acpi_match[] = {
	{ "INT33C7", (kernel_ulong_t)&lptlp_soc_data },
	{ "INT3437", (kernel_ulong_t)&lptlp_soc_data },
	{ }
};
MODULE_DEVICE_TABLE(acpi, lynxpoint_gpio_acpi_match);

static struct platform_driver lp_gpio_driver = {
	.probe          = lp_gpio_probe,
	.remove         = lp_gpio_remove,
	.driver         = {
		.name   = "lp_gpio",
		.pm	= &lp_gpio_pm_ops,
		.acpi_match_table = ACPI_PTR(lynxpoint_gpio_acpi_match),
	},
};

static int __init lp_gpio_init(void)
{
	return platform_driver_register(&lp_gpio_driver);
}

static void __exit lp_gpio_exit(void)
{
	platform_driver_unregister(&lp_gpio_driver);
}

subsys_initcall(lp_gpio_init);
module_exit(lp_gpio_exit);

MODULE_AUTHOR("Mathias Nyman (Intel)");
MODULE_DESCRIPTION("GPIO interface for Intel Lynxpoint");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:lp_gpio");