drivers/gpio/gpio-xgene-sb.c - kernel/quantenna - Git at Google

 /*
  * AppliedMicro X-Gene SoC GPIO-Standby Driver
  *
  * Copyright (c) 2014, Applied Micro Circuits Corporation
  * Author:	Tin Huynh <tnhuynh@apm.com>.
  *		Y Vo <yvo@apm.com>.
  *		Quan Nguyen <qnguyen@apm.com>.
  *
  * 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, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/of_gpio.h>
 #include <linux/gpio/driver.h>
 #include <linux/acpi.h>

 #include "gpiolib.h"

 /* Common property names */
 #define XGENE_NIRQ_PROPERTY		"apm,nr-irqs"
 #define XGENE_NGPIO_PROPERTY		"apm,nr-gpios"
 #define XGENE_IRQ_START_PROPERTY	"apm,irq-start"

 #define XGENE_DFLT_MAX_NGPIO		22
 #define XGENE_DFLT_MAX_NIRQ		6
 #define XGENE_DFLT_IRQ_START_PIN	8
 #define GPIO_MASK(x)			(1U << ((x) % 32))

 #define MPA_GPIO_INT_LVL		0x0290
 #define MPA_GPIO_OE_ADDR		0x029c
 #define MPA_GPIO_OUT_ADDR		0x02a0
 #define MPA_GPIO_IN_ADDR 		0x02a4
 #define MPA_GPIO_SEL_LO 		0x0294

 #define GPIO_INT_LEVEL_H	0x000001
 #define GPIO_INT_LEVEL_L	0x000000

 /**
  * struct xgene_gpio_sb - GPIO-Standby private data structure.
  * @gc:				memory-mapped GPIO controllers.
  * @regs:			GPIO register base offset
  * @irq_domain:			GPIO interrupt domain
  * @irq_start:			GPIO pin that start support interrupt
  * @nirq:			Number of GPIO pins that supports interrupt
  * @parent_irq_base:		Start parent HWIRQ
  */
 struct xgene_gpio_sb {
 	struct gpio_chip	gc;
 	void __iomem		*regs;
 	struct irq_domain	*irq_domain;
 	u16			irq_start;
 	u16			nirq;
 	u16			parent_irq_base;
 };

 #define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
 #define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)

 static void xgene_gpio_set_bit(struct gpio_chip *gc,
 				void __iomem *reg, u32 gpio, int val)
 {
 	u32 data;

 	data = gc->read_reg(reg);
 	if (val)
 		data |= GPIO_MASK(gpio);
 	else
 		data &= ~GPIO_MASK(gpio);
 	gc->write_reg(reg, data);
 }

 static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
 	int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
 	int lvl_type = GPIO_INT_LEVEL_H;

 	switch (type & IRQ_TYPE_SENSE_MASK) {
 	case IRQ_TYPE_EDGE_RISING:
 	case IRQ_TYPE_LEVEL_HIGH:
 		lvl_type = GPIO_INT_LEVEL_H;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 	case IRQ_TYPE_LEVEL_LOW:
 		lvl_type = GPIO_INT_LEVEL_L;
 		break;
 	default:
 		break;
 	}

 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
 			gpio * 2, 1);
 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
 			d->hwirq, lvl_type);

 	/* Propagate IRQ type setting to parent */
 	if (type & IRQ_TYPE_EDGE_BOTH)
 		return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
 	else
 		return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
 }

 static struct irq_chip xgene_gpio_sb_irq_chip = {
 	.name           = "sbgpio",
 	.irq_eoi	= irq_chip_eoi_parent,
 	.irq_mask       = irq_chip_mask_parent,
 	.irq_unmask     = irq_chip_unmask_parent,
 	.irq_set_type   = xgene_gpio_sb_irq_set_type,
 };

 static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
 {
 	struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
 	struct irq_fwspec fwspec;

 	if ((gpio < priv->irq_start) ||
 			(gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
 		return -ENXIO;

 	if (gc->parent->of_node)
 		fwspec.fwnode = of_node_to_fwnode(gc->parent->of_node);
 	else
 		fwspec.fwnode = gc->parent->fwnode;
 	fwspec.param_count = 2;
 	fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
 	fwspec.param[1] = IRQ_TYPE_NONE;
 	return irq_create_fwspec_mapping(&fwspec);
 }

 static void xgene_gpio_sb_domain_activate(struct irq_domain *d,
 		struct irq_data *irq_data)
 {
 	struct xgene_gpio_sb *priv = d->host_data;
 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);

 	if (gpiochip_lock_as_irq(&priv->gc, gpio)) {
 		dev_err(priv->gc.parent,
 		"Unable to configure XGene GPIO standby pin %d as IRQ\n",
 				gpio);
 		return;
 	}

 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
 			gpio * 2, 1);
 }

 static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
 		struct irq_data *irq_data)
 {
 	struct xgene_gpio_sb *priv = d->host_data;
 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);

 	gpiochip_unlock_as_irq(&priv->gc, gpio);
 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
 			gpio * 2, 0);
 }

 static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
 		struct irq_fwspec *fwspec,
 		unsigned long *hwirq,
 		unsigned int *type)
 {
 	struct xgene_gpio_sb *priv = d->host_data;

 	if ((fwspec->param_count != 2) ||
 		(fwspec->param[0] >= priv->nirq))
 		return -EINVAL;
 	*hwirq = fwspec->param[0];
 	*type = fwspec->param[1];
 	return 0;
 }

 static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
 					unsigned int virq,
 					unsigned int nr_irqs, void *data)
 {
 	struct irq_fwspec *fwspec = data;
 	struct irq_fwspec parent_fwspec;
 	struct xgene_gpio_sb *priv = domain->host_data;
 	irq_hw_number_t hwirq;
 	unsigned int i;

 	hwirq = fwspec->param[0];
 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
 				&xgene_gpio_sb_irq_chip, priv);

 	parent_fwspec.fwnode = domain->parent->fwnode;
 	if (is_of_node(parent_fwspec.fwnode)) {
 		parent_fwspec.param_count = 3;
 		parent_fwspec.param[0] = 0;/* SPI */
 		/* Skip SGIs and PPIs*/
 		parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
 		parent_fwspec.param[2] = fwspec->param[1];
 	} else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
 		parent_fwspec.param_count = 2;
 		parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
 		parent_fwspec.param[1] = fwspec->param[1];
 	} else
 		return -EINVAL;

 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 			&parent_fwspec);
 }

 static void xgene_gpio_sb_domain_free(struct irq_domain *domain,
 		unsigned int virq,
 		unsigned int nr_irqs)
 {
 	struct irq_data *d;
 	unsigned int i;

 	for (i = 0; i < nr_irqs; i++) {
 		d = irq_domain_get_irq_data(domain, virq + i);
 		irq_domain_reset_irq_data(d);
 	}
 }

 static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
 	.translate      = xgene_gpio_sb_domain_translate,
 	.alloc          = xgene_gpio_sb_domain_alloc,
 	.free           = xgene_gpio_sb_domain_free,
 	.activate	= xgene_gpio_sb_domain_activate,
 	.deactivate	= xgene_gpio_sb_domain_deactivate,
 };

 static int xgene_gpio_sb_probe(struct platform_device *pdev)
 {
 	struct xgene_gpio_sb *priv;
 	int ret;
 	struct resource *res;
 	void __iomem *regs;
 	struct irq_domain *parent_domain = NULL;
 	struct fwnode_handle *fwnode;
 	u32 val32;

 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);

 	priv->regs = regs;

 	ret = platform_get_irq(pdev, 0);
 	if (ret > 0) {
 		priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
 		parent_domain = irq_get_irq_data(ret)->domain;
 	}
 	if (!parent_domain) {
 		dev_err(&pdev->dev, "unable to obtain parent domain\n");
 		return -ENODEV;
 	}

 	ret = bgpio_init(&priv->gc, &pdev->dev, 4,
 			regs + MPA_GPIO_IN_ADDR,
 			regs + MPA_GPIO_OUT_ADDR, NULL,
 			regs + MPA_GPIO_OE_ADDR, NULL, 0);
         if (ret)
                 return ret;

 	priv->gc.to_irq = xgene_gpio_sb_to_irq;

 	/* Retrieve start irq pin, use default if property not found */
 	priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
 	if (!device_property_read_u32(&pdev->dev,
 					XGENE_IRQ_START_PROPERTY, &val32))
 		priv->irq_start = val32;

 	/* Retrieve number irqs, use default if property not found */
 	priv->nirq = XGENE_DFLT_MAX_NIRQ;
 	if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
 		priv->nirq = val32;

 	/* Retrieve number gpio, use default if property not found */
 	priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
 	if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
 		priv->gc.ngpio = val32;

 	dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
 			priv->gc.ngpio, priv->nirq, priv->irq_start);

 	platform_set_drvdata(pdev, priv);

 	if (pdev->dev.of_node)
 		fwnode = of_node_to_fwnode(pdev->dev.of_node);
 	else
 		fwnode = pdev->dev.fwnode;

 	priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
 					0, priv->nirq, fwnode,
 					&xgene_gpio_sb_domain_ops, priv);
 	if (!priv->irq_domain)
 		return -ENODEV;

 	priv->gc.irqdomain = priv->irq_domain;

 	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
 	if (ret) {
 		dev_err(&pdev->dev,
 			"failed to register X-Gene GPIO Standby driver\n");
 		irq_domain_remove(priv->irq_domain);
 		return ret;
 	}

 	dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");

 	if (priv->nirq > 0) {
 		/* Register interrupt handlers for gpio signaled acpi events */
 		acpi_gpiochip_request_interrupts(&priv->gc);
 	}

 	return ret;
 }

 static int xgene_gpio_sb_remove(struct platform_device *pdev)
 {
 	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);

 	if (priv->nirq > 0) {
 		acpi_gpiochip_free_interrupts(&priv->gc);
 	}

 	irq_domain_remove(priv->irq_domain);

 	return 0;
 }

 static const struct of_device_id xgene_gpio_sb_of_match[] = {
 	{.compatible = "apm,xgene-gpio-sb", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
 	{"APMC0D15", 0},
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
 #endif

 static struct platform_driver xgene_gpio_sb_driver = {
 	.driver = {
 		   .name = "xgene-gpio-sb",
 		   .of_match_table = xgene_gpio_sb_of_match,
 		   .acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
 		   },
 	.probe = xgene_gpio_sb_probe,
 	.remove = xgene_gpio_sb_remove,
 };
 module_platform_driver(xgene_gpio_sb_driver);

 MODULE_AUTHOR("AppliedMicro");
 MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
 MODULE_LICENSE("GPL");
	/*
	* AppliedMicro X-Gene SoC GPIO-Standby Driver
	*
	* Copyright (c) 2014, Applied Micro Circuits Corporation
	* Author: Tin Huynh <tnhuynh@apm.com>.
	* Y Vo <yvo@apm.com>.
	* Quan Nguyen <qnguyen@apm.com>.
	*
	* 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, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/module.h>
	#include <linux/io.h>
	#include <linux/platform_device.h>
	#include <linux/of_gpio.h>
	#include <linux/gpio/driver.h>
	#include <linux/acpi.h>

	#include "gpiolib.h"

	/* Common property names */
	#define XGENE_NIRQ_PROPERTY "apm,nr-irqs"
	#define XGENE_NGPIO_PROPERTY "apm,nr-gpios"
	#define XGENE_IRQ_START_PROPERTY "apm,irq-start"

	#define XGENE_DFLT_MAX_NGPIO 22
	#define XGENE_DFLT_MAX_NIRQ 6
	#define XGENE_DFLT_IRQ_START_PIN 8
	#define GPIO_MASK(x) (1U << ((x) % 32))

	#define MPA_GPIO_INT_LVL 0x0290
	#define MPA_GPIO_OE_ADDR 0x029c
	#define MPA_GPIO_OUT_ADDR 0x02a0
	#define MPA_GPIO_IN_ADDR 0x02a4
	#define MPA_GPIO_SEL_LO 0x0294

	#define GPIO_INT_LEVEL_H 0x000001
	#define GPIO_INT_LEVEL_L 0x000000

	/**
	* struct xgene_gpio_sb - GPIO-Standby private data structure.
	* @gc: memory-mapped GPIO controllers.
	* @regs: GPIO register base offset
	* @irq_domain: GPIO interrupt domain
	* @irq_start: GPIO pin that start support interrupt
	* @nirq: Number of GPIO pins that supports interrupt
	* @parent_irq_base: Start parent HWIRQ
	*/
	struct xgene_gpio_sb {
	struct gpio_chip gc;
	void __iomem *regs;
	struct irq_domain *irq_domain;
	u16 irq_start;
	u16 nirq;
	u16 parent_irq_base;
	};

	#define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
	#define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)

	static void xgene_gpio_set_bit(struct gpio_chip *gc,
	void __iomem *reg, u32 gpio, int val)
	{
	u32 data;

	data = gc->read_reg(reg);
	if (val)
	data \|= GPIO_MASK(gpio);
	else
	data &= ~GPIO_MASK(gpio);
	gc->write_reg(reg, data);
	}

	static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
	{
	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
	int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
	int lvl_type = GPIO_INT_LEVEL_H;

	switch (type & IRQ_TYPE_SENSE_MASK) {
	case IRQ_TYPE_EDGE_RISING:
	case IRQ_TYPE_LEVEL_HIGH:
	lvl_type = GPIO_INT_LEVEL_H;
	break;
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_LEVEL_LOW:
	lvl_type = GPIO_INT_LEVEL_L;
	break;
	default:
	break;
	}

	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
	gpio * 2, 1);
	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
	d->hwirq, lvl_type);

	/* Propagate IRQ type setting to parent */
	if (type & IRQ_TYPE_EDGE_BOTH)
	return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
	else
	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
	}

	static struct irq_chip xgene_gpio_sb_irq_chip = {
	.name = "sbgpio",
	.irq_eoi = irq_chip_eoi_parent,
	.irq_mask = irq_chip_mask_parent,
	.irq_unmask = irq_chip_unmask_parent,
	.irq_set_type = xgene_gpio_sb_irq_set_type,
	};

	static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
	{
	struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
	struct irq_fwspec fwspec;

	if ((gpio < priv->irq_start) \|\|
	(gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
	return -ENXIO;

	if (gc->parent->of_node)
	fwspec.fwnode = of_node_to_fwnode(gc->parent->of_node);
	else
	fwspec.fwnode = gc->parent->fwnode;
	fwspec.param_count = 2;
	fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
	fwspec.param[1] = IRQ_TYPE_NONE;
	return irq_create_fwspec_mapping(&fwspec);
	}

	static void xgene_gpio_sb_domain_activate(struct irq_domain *d,
	struct irq_data *irq_data)
	{
	struct xgene_gpio_sb *priv = d->host_data;
	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);

	if (gpiochip_lock_as_irq(&priv->gc, gpio)) {
	dev_err(priv->gc.parent,
	"Unable to configure XGene GPIO standby pin %d as IRQ\n",
	gpio);
	return;
	}

	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
	gpio * 2, 1);
	}

	static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
	struct irq_data *irq_data)
	{
	struct xgene_gpio_sb *priv = d->host_data;
	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);

	gpiochip_unlock_as_irq(&priv->gc, gpio);
	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
	gpio * 2, 0);
	}

	static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
	struct irq_fwspec *fwspec,
	unsigned long *hwirq,
	unsigned int *type)
	{
	struct xgene_gpio_sb *priv = d->host_data;

	if ((fwspec->param_count != 2) \|\|
	(fwspec->param[0] >= priv->nirq))
	return -EINVAL;
	*hwirq = fwspec->param[0];
	*type = fwspec->param[1];
	return 0;
	}

	static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
	unsigned int virq,
	unsigned int nr_irqs, void *data)
	{
	struct irq_fwspec *fwspec = data;
	struct irq_fwspec parent_fwspec;
	struct xgene_gpio_sb *priv = domain->host_data;
	irq_hw_number_t hwirq;
	unsigned int i;

	hwirq = fwspec->param[0];
	for (i = 0; i < nr_irqs; i++)
	irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
	&xgene_gpio_sb_irq_chip, priv);

	parent_fwspec.fwnode = domain->parent->fwnode;
	if (is_of_node(parent_fwspec.fwnode)) {
	parent_fwspec.param_count = 3;
	parent_fwspec.param[0] = 0;/* SPI */
	/* Skip SGIs and PPIs*/
	parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
	parent_fwspec.param[2] = fwspec->param[1];
	} else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
	parent_fwspec.param_count = 2;
	parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
	parent_fwspec.param[1] = fwspec->param[1];
	} else
	return -EINVAL;

	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
	&parent_fwspec);
	}

	static void xgene_gpio_sb_domain_free(struct irq_domain *domain,
	unsigned int virq,
	unsigned int nr_irqs)
	{
	struct irq_data *d;
	unsigned int i;

	for (i = 0; i < nr_irqs; i++) {
	d = irq_domain_get_irq_data(domain, virq + i);
	irq_domain_reset_irq_data(d);
	}
	}

	static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
	.translate = xgene_gpio_sb_domain_translate,
	.alloc = xgene_gpio_sb_domain_alloc,
	.free = xgene_gpio_sb_domain_free,
	.activate = xgene_gpio_sb_domain_activate,
	.deactivate = xgene_gpio_sb_domain_deactivate,
	};

	static int xgene_gpio_sb_probe(struct platform_device *pdev)
	{
	struct xgene_gpio_sb *priv;
	int ret;
	struct resource *res;
	void __iomem *regs;
	struct irq_domain *parent_domain = NULL;
	struct fwnode_handle *fwnode;
	u32 val32;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(regs))
	return PTR_ERR(regs);

	priv->regs = regs;

	ret = platform_get_irq(pdev, 0);
	if (ret > 0) {
	priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
	parent_domain = irq_get_irq_data(ret)->domain;
	}
	if (!parent_domain) {
	dev_err(&pdev->dev, "unable to obtain parent domain\n");
	return -ENODEV;
	}

	ret = bgpio_init(&priv->gc, &pdev->dev, 4,
	regs + MPA_GPIO_IN_ADDR,
	regs + MPA_GPIO_OUT_ADDR, NULL,
	regs + MPA_GPIO_OE_ADDR, NULL, 0);
	if (ret)
	return ret;

	priv->gc.to_irq = xgene_gpio_sb_to_irq;

	/* Retrieve start irq pin, use default if property not found */
	priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
	if (!device_property_read_u32(&pdev->dev,
	XGENE_IRQ_START_PROPERTY, &val32))
	priv->irq_start = val32;

	/* Retrieve number irqs, use default if property not found */
	priv->nirq = XGENE_DFLT_MAX_NIRQ;
	if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
	priv->nirq = val32;

	/* Retrieve number gpio, use default if property not found */
	priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
	if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
	priv->gc.ngpio = val32;

	dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
	priv->gc.ngpio, priv->nirq, priv->irq_start);

	platform_set_drvdata(pdev, priv);

	if (pdev->dev.of_node)
	fwnode = of_node_to_fwnode(pdev->dev.of_node);
	else
	fwnode = pdev->dev.fwnode;

	priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
	0, priv->nirq, fwnode,
	&xgene_gpio_sb_domain_ops, priv);
	if (!priv->irq_domain)
	return -ENODEV;

	priv->gc.irqdomain = priv->irq_domain;

	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
	if (ret) {
	dev_err(&pdev->dev,
	"failed to register X-Gene GPIO Standby driver\n");
	irq_domain_remove(priv->irq_domain);
	return ret;
	}

	dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");

	if (priv->nirq > 0) {
	/* Register interrupt handlers for gpio signaled acpi events */
	acpi_gpiochip_request_interrupts(&priv->gc);
	}

	return ret;
	}

	static int xgene_gpio_sb_remove(struct platform_device *pdev)
	{
	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);

	if (priv->nirq > 0) {
	acpi_gpiochip_free_interrupts(&priv->gc);
	}

	irq_domain_remove(priv->irq_domain);

	return 0;
	}

	static const struct of_device_id xgene_gpio_sb_of_match[] = {
	{.compatible = "apm,xgene-gpio-sb", },
	{},
	};
	MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
	{"APMC0D15", 0},
	{},
	};
	MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
	#endif

	static struct platform_driver xgene_gpio_sb_driver = {
	.driver = {
	.name = "xgene-gpio-sb",
	.of_match_table = xgene_gpio_sb_of_match,
	.acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
	},
	.probe = xgene_gpio_sb_probe,
	.remove = xgene_gpio_sb_remove,
	};
	module_platform_driver(xgene_gpio_sb_driver);

	MODULE_AUTHOR("AppliedMicro");
	MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
	MODULE_LICENSE("GPL");