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

 /*
  * Copyright (c) 2011 Jamie Iles
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * All enquiries to support@picochip.com
  */
 #include <linux/basic_mmio_gpio.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>

 #define GPIO_SWPORTA_DR		0x00
 #define GPIO_SWPORTA_DDR	0x04
 #define GPIO_SWPORTB_DR		0x0c
 #define GPIO_SWPORTB_DDR	0x10
 #define GPIO_SWPORTC_DR		0x18
 #define GPIO_SWPORTC_DDR	0x1c
 #define GPIO_SWPORTD_DR		0x24
 #define GPIO_SWPORTD_DDR	0x28
 #define GPIO_INTEN		0x30
 #define GPIO_INTMASK		0x34
 #define GPIO_INTTYPE_LEVEL	0x38
 #define GPIO_INT_POLARITY	0x3c
 #define GPIO_INTSTATUS		0x40
 #define GPIO_PORTA_EOI		0x4c
 #define GPIO_EXT_PORTA		0x50
 #define GPIO_EXT_PORTB		0x54
 #define GPIO_EXT_PORTC		0x58
 #define GPIO_EXT_PORTD		0x5c

 #define DWAPB_MAX_PORTS		4
 #define GPIO_EXT_PORT_SIZE	(GPIO_EXT_PORTB - GPIO_EXT_PORTA)
 #define GPIO_SWPORT_DR_SIZE	(GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
 #define GPIO_SWPORT_DDR_SIZE	(GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)

 struct dwapb_gpio;

 struct dwapb_gpio_port {
 	struct bgpio_chip	bgc;
 	bool			is_registered;
 	struct dwapb_gpio	*gpio;
 };

 struct dwapb_gpio {
 	struct	device		*dev;
 	void __iomem		*regs;
 	struct dwapb_gpio_port	*ports;
 	unsigned int		nr_ports;
 	struct irq_domain	*domain;
 };

 static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 {
 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
 	struct dwapb_gpio_port *port = container_of(bgc, struct
 						    dwapb_gpio_port, bgc);
 	struct dwapb_gpio *gpio = port->gpio;

 	return irq_find_mapping(gpio->domain, offset);
 }

 static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
 {
 	u32 v = readl(gpio->regs + GPIO_INT_POLARITY);

 	if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs))
 		v &= ~BIT(offs);
 	else
 		v |= BIT(offs);

 	writel(v, gpio->regs + GPIO_INT_POLARITY);
 }

 static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
 {
 	struct dwapb_gpio *gpio = irq_get_handler_data(irq);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);

 	while (irq_status) {
 		int hwirq = fls(irq_status) - 1;
 		int gpio_irq = irq_find_mapping(gpio->domain, hwirq);

 		generic_handle_irq(gpio_irq);
 		irq_status &= ~BIT(hwirq);

 		if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
 			== IRQ_TYPE_EDGE_BOTH)
 			dwapb_toggle_trigger(gpio, hwirq);
 	}

 	if (chip->irq_eoi)
 		chip->irq_eoi(irq_desc_get_irq_data(desc));
 }

 static void dwapb_irq_enable(struct irq_data *d)
 {
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
 	unsigned long flags;
 	u32 val;

 	spin_lock_irqsave(&bgc->lock, flags);
 	val = readl(gpio->regs + GPIO_INTEN);
 	val |= BIT(d->hwirq);
 	writel(val, gpio->regs + GPIO_INTEN);
 	spin_unlock_irqrestore(&bgc->lock, flags);
 }

 static void dwapb_irq_disable(struct irq_data *d)
 {
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
 	unsigned long flags;
 	u32 val;

 	spin_lock_irqsave(&bgc->lock, flags);
 	val = readl(gpio->regs + GPIO_INTEN);
 	val &= ~BIT(d->hwirq);
 	writel(val, gpio->regs + GPIO_INTEN);
 	spin_unlock_irqrestore(&bgc->lock, flags);
 }

 static int dwapb_irq_reqres(struct irq_data *d)
 {
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;

 	if (gpio_lock_as_irq(&bgc->gc, irqd_to_hwirq(d))) {
 		dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
 			irqd_to_hwirq(d));
 		return -EINVAL;
 	}
 	return 0;
 }

 static void dwapb_irq_relres(struct irq_data *d)
 {
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;

 	gpio_unlock_as_irq(&bgc->gc, irqd_to_hwirq(d));
 }

 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
 {
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
 	int bit = d->hwirq;
 	unsigned long level, polarity, flags;

 	if (type & ~(IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING |
 		     IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 		return -EINVAL;

 	spin_lock_irqsave(&bgc->lock, flags);
 	level = readl(gpio->regs + GPIO_INTTYPE_LEVEL);
 	polarity = readl(gpio->regs + GPIO_INT_POLARITY);

 	switch (type) {
 	case IRQ_TYPE_EDGE_BOTH:
 		level |= BIT(bit);
 		dwapb_toggle_trigger(gpio, bit);
 		break;
 	case IRQ_TYPE_EDGE_RISING:
 		level |= BIT(bit);
 		polarity |= BIT(bit);
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		level |= BIT(bit);
 		polarity &= ~BIT(bit);
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 		level &= ~BIT(bit);
 		polarity |= BIT(bit);
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		level &= ~BIT(bit);
 		polarity &= ~BIT(bit);
 		break;
 	}

 	writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
 	writel(polarity, gpio->regs + GPIO_INT_POLARITY);
 	spin_unlock_irqrestore(&bgc->lock, flags);

 	return 0;
 }

 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
 				 struct dwapb_gpio_port *port)
 {
 	struct gpio_chip *gc = &port->bgc.gc;
 	struct device_node *node =  gc->of_node;
 	struct irq_chip_generic	*irq_gc;
 	unsigned int hwirq, ngpio = gc->ngpio;
 	struct irq_chip_type *ct;
 	int err, irq;

 	irq = irq_of_parse_and_map(node, 0);
 	if (!irq) {
 		dev_warn(gpio->dev, "no irq for bank %s\n",
 			port->bgc.gc.of_node->full_name);
 		return;
 	}

 	gpio->domain = irq_domain_add_linear(node, ngpio,
 					     &irq_generic_chip_ops, gpio);
 	if (!gpio->domain)
 		return;

 	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1,
 					     "gpio-dwapb", handle_level_irq,
 					     IRQ_NOREQUEST, 0,
 					     IRQ_GC_INIT_NESTED_LOCK);
 	if (err) {
 		dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n");
 		irq_domain_remove(gpio->domain);
 		gpio->domain = NULL;
 		return;
 	}

 	irq_gc = irq_get_domain_generic_chip(gpio->domain, 0);
 	if (!irq_gc) {
 		irq_domain_remove(gpio->domain);
 		gpio->domain = NULL;
 		return;
 	}

 	irq_gc->reg_base = gpio->regs;
 	irq_gc->private = gpio;

 	ct = irq_gc->chip_types;
 	ct->chip.irq_ack = irq_gc_ack_set_bit;
 	ct->chip.irq_mask = irq_gc_mask_set_bit;
 	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 	ct->chip.irq_set_type = dwapb_irq_set_type;
 	ct->chip.irq_enable = dwapb_irq_enable;
 	ct->chip.irq_disable = dwapb_irq_disable;
 	ct->chip.irq_request_resources = dwapb_irq_reqres;
 	ct->chip.irq_release_resources = dwapb_irq_relres;
 	ct->regs.ack = GPIO_PORTA_EOI;
 	ct->regs.mask = GPIO_INTMASK;

 	irq_setup_generic_chip(irq_gc, IRQ_MSK(port->bgc.gc.ngpio),
 			IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);

 	irq_set_chained_handler(irq, dwapb_irq_handler);
 	irq_set_handler_data(irq, gpio);

 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
 		irq_create_mapping(gpio->domain, hwirq);

 	port->bgc.gc.to_irq = dwapb_gpio_to_irq;
 }

 static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
 {
 	struct dwapb_gpio_port *port = &gpio->ports[0];
 	struct gpio_chip *gc = &port->bgc.gc;
 	unsigned int ngpio = gc->ngpio;
 	irq_hw_number_t hwirq;

 	if (!gpio->domain)
 		return;

 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
 		irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq));

 	irq_domain_remove(gpio->domain);
 	gpio->domain = NULL;
 }

 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 			       struct device_node *port_np,
 			       unsigned int offs)
 {
 	struct dwapb_gpio_port *port;
 	u32 port_idx, ngpio;
 	void __iomem *dat, *set, *dirout;
 	int err;

 	if (of_property_read_u32(port_np, "reg", &port_idx) ||
 		port_idx >= DWAPB_MAX_PORTS) {
 		dev_err(gpio->dev, "missing/invalid port index for %s\n",
 			port_np->full_name);
 		return -EINVAL;
 	}

 	port = &gpio->ports[offs];
 	port->gpio = gpio;

 	if (of_property_read_u32(port_np, "snps,nr-gpios", &ngpio)) {
 		dev_info(gpio->dev, "failed to get number of gpios for %s\n",
 			 port_np->full_name);
 		ngpio = 32;
 	}

 	dat = gpio->regs + GPIO_EXT_PORTA + (port_idx * GPIO_EXT_PORT_SIZE);
 	set = gpio->regs + GPIO_SWPORTA_DR + (port_idx * GPIO_SWPORT_DR_SIZE);
 	dirout = gpio->regs + GPIO_SWPORTA_DDR +
 		(port_idx * GPIO_SWPORT_DDR_SIZE);

 	err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout,
 			 NULL, false);
 	if (err) {
 		dev_err(gpio->dev, "failed to init gpio chip for %s\n",
 			port_np->full_name);
 		return err;
 	}

 	port->bgc.gc.ngpio = ngpio;
 	port->bgc.gc.of_node = port_np;

 	/*
 	 * Only port A can provide interrupts in all configurations of the IP.
 	 */
 	if (port_idx == 0 &&
 	    of_property_read_bool(port_np, "interrupt-controller"))
 		dwapb_configure_irqs(gpio, port);

 	err = gpiochip_add(&port->bgc.gc);
 	if (err)
 		dev_err(gpio->dev, "failed to register gpiochip for %s\n",
 			port_np->full_name);
 	else
 		port->is_registered = true;

 	return err;
 }

 static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
 {
 	unsigned int m;

 	for (m = 0; m < gpio->nr_ports; ++m)
 		if (gpio->ports[m].is_registered)
 			WARN_ON(gpiochip_remove(&gpio->ports[m].bgc.gc));
 }

 static int dwapb_gpio_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct dwapb_gpio *gpio;
 	struct device_node *np;
 	int err;
 	unsigned int offs = 0;

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

 	gpio->nr_ports = of_get_child_count(pdev->dev.of_node);
 	if (!gpio->nr_ports) {
 		err = -EINVAL;
 		goto out_err;
 	}
 	gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports *
 				   sizeof(*gpio->ports), GFP_KERNEL);
 	if (!gpio->ports) {
 		err = -ENOMEM;
 		goto out_err;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	gpio->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(gpio->regs)) {
 		err = PTR_ERR(gpio->regs);
 		goto out_err;
 	}

 	for_each_child_of_node(pdev->dev.of_node, np) {
 		err = dwapb_gpio_add_port(gpio, np, offs++);
 		if (err)
 			goto out_unregister;
 	}
 	platform_set_drvdata(pdev, gpio);

 	return 0;

 out_unregister:
 	dwapb_gpio_unregister(gpio);
 	dwapb_irq_teardown(gpio);

 out_err:
 	return err;
 }

 static int dwapb_gpio_remove(struct platform_device *pdev)
 {
 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);

 	dwapb_gpio_unregister(gpio);
 	dwapb_irq_teardown(gpio);

 	return 0;
 }

 static const struct of_device_id dwapb_of_match[] = {
 	{ .compatible = "snps,dw-apb-gpio" },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dwapb_of_match);

 static struct platform_driver dwapb_gpio_driver = {
 	.driver		= {
 		.name	= "gpio-dwapb",
 		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(dwapb_of_match),
 	},
 	.probe		= dwapb_gpio_probe,
 	.remove		= dwapb_gpio_remove,
 };

 module_platform_driver(dwapb_gpio_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Jamie Iles");
 MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
	/*
	* Copyright (c) 2011 Jamie Iles
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* All enquiries to support@picochip.com
	*/
	#include <linux/basic_mmio_gpio.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/ioport.h>
	#include <linux/irq.h>
	#include <linux/irqdomain.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>

	#define GPIO_SWPORTA_DR 0x00
	#define GPIO_SWPORTA_DDR 0x04
	#define GPIO_SWPORTB_DR 0x0c
	#define GPIO_SWPORTB_DDR 0x10
	#define GPIO_SWPORTC_DR 0x18
	#define GPIO_SWPORTC_DDR 0x1c
	#define GPIO_SWPORTD_DR 0x24
	#define GPIO_SWPORTD_DDR 0x28
	#define GPIO_INTEN 0x30
	#define GPIO_INTMASK 0x34
	#define GPIO_INTTYPE_LEVEL 0x38
	#define GPIO_INT_POLARITY 0x3c
	#define GPIO_INTSTATUS 0x40
	#define GPIO_PORTA_EOI 0x4c
	#define GPIO_EXT_PORTA 0x50
	#define GPIO_EXT_PORTB 0x54
	#define GPIO_EXT_PORTC 0x58
	#define GPIO_EXT_PORTD 0x5c

	#define DWAPB_MAX_PORTS 4
	#define GPIO_EXT_PORT_SIZE (GPIO_EXT_PORTB - GPIO_EXT_PORTA)
	#define GPIO_SWPORT_DR_SIZE (GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
	#define GPIO_SWPORT_DDR_SIZE (GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)

	struct dwapb_gpio;

	struct dwapb_gpio_port {
	struct bgpio_chip bgc;
	bool is_registered;
	struct dwapb_gpio *gpio;
	};

	struct dwapb_gpio {
	struct device *dev;
	void __iomem *regs;
	struct dwapb_gpio_port *ports;
	unsigned int nr_ports;
	struct irq_domain *domain;
	};

	static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
	{
	struct bgpio_chip *bgc = to_bgpio_chip(gc);
	struct dwapb_gpio_port *port = container_of(bgc, struct
	dwapb_gpio_port, bgc);
	struct dwapb_gpio *gpio = port->gpio;

	return irq_find_mapping(gpio->domain, offset);
	}

	static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
	{
	u32 v = readl(gpio->regs + GPIO_INT_POLARITY);

	if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs))
	v &= ~BIT(offs);
	else
	v \|= BIT(offs);

	writel(v, gpio->regs + GPIO_INT_POLARITY);
	}

	static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
	{
	struct dwapb_gpio *gpio = irq_get_handler_data(irq);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);

	while (irq_status) {
	int hwirq = fls(irq_status) - 1;
	int gpio_irq = irq_find_mapping(gpio->domain, hwirq);

	generic_handle_irq(gpio_irq);
	irq_status &= ~BIT(hwirq);

	if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
	== IRQ_TYPE_EDGE_BOTH)
	dwapb_toggle_trigger(gpio, hwirq);
	}

	if (chip->irq_eoi)
	chip->irq_eoi(irq_desc_get_irq_data(desc));
	}

	static void dwapb_irq_enable(struct irq_data *d)
	{
	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
	struct dwapb_gpio *gpio = igc->private;
	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&bgc->lock, flags);
	val = readl(gpio->regs + GPIO_INTEN);
	val \|= BIT(d->hwirq);
	writel(val, gpio->regs + GPIO_INTEN);
	spin_unlock_irqrestore(&bgc->lock, flags);
	}

	static void dwapb_irq_disable(struct irq_data *d)
	{
	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
	struct dwapb_gpio *gpio = igc->private;
	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&bgc->lock, flags);
	val = readl(gpio->regs + GPIO_INTEN);
	val &= ~BIT(d->hwirq);
	writel(val, gpio->regs + GPIO_INTEN);
	spin_unlock_irqrestore(&bgc->lock, flags);
	}

	static int dwapb_irq_reqres(struct irq_data *d)
	{
	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
	struct dwapb_gpio *gpio = igc->private;
	struct bgpio_chip *bgc = &gpio->ports[0].bgc;

	if (gpio_lock_as_irq(&bgc->gc, irqd_to_hwirq(d))) {
	dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
	irqd_to_hwirq(d));
	return -EINVAL;
	}
	return 0;
	}

	static void dwapb_irq_relres(struct irq_data *d)
	{
	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
	struct dwapb_gpio *gpio = igc->private;
	struct bgpio_chip *bgc = &gpio->ports[0].bgc;

	gpio_unlock_as_irq(&bgc->gc, irqd_to_hwirq(d));
	}

	static int dwapb_irq_set_type(struct irq_data *d, u32 type)
	{
	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
	struct dwapb_gpio *gpio = igc->private;
	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
	int bit = d->hwirq;
	unsigned long level, polarity, flags;

	if (type & ~(IRQ_TYPE_EDGE_RISING \| IRQ_TYPE_EDGE_FALLING \|
	IRQ_TYPE_LEVEL_HIGH \| IRQ_TYPE_LEVEL_LOW))
	return -EINVAL;

	spin_lock_irqsave(&bgc->lock, flags);
	level = readl(gpio->regs + GPIO_INTTYPE_LEVEL);
	polarity = readl(gpio->regs + GPIO_INT_POLARITY);

	switch (type) {
	case IRQ_TYPE_EDGE_BOTH:
	level \|= BIT(bit);
	dwapb_toggle_trigger(gpio, bit);
	break;
	case IRQ_TYPE_EDGE_RISING:
	level \|= BIT(bit);
	polarity \|= BIT(bit);
	break;
	case IRQ_TYPE_EDGE_FALLING:
	level \|= BIT(bit);
	polarity &= ~BIT(bit);
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	level &= ~BIT(bit);
	polarity \|= BIT(bit);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	level &= ~BIT(bit);
	polarity &= ~BIT(bit);
	break;
	}

	writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
	writel(polarity, gpio->regs + GPIO_INT_POLARITY);
	spin_unlock_irqrestore(&bgc->lock, flags);

	return 0;
	}

	static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
	struct dwapb_gpio_port *port)
	{
	struct gpio_chip *gc = &port->bgc.gc;
	struct device_node *node = gc->of_node;
	struct irq_chip_generic *irq_gc;
	unsigned int hwirq, ngpio = gc->ngpio;
	struct irq_chip_type *ct;
	int err, irq;

	irq = irq_of_parse_and_map(node, 0);
	if (!irq) {
	dev_warn(gpio->dev, "no irq for bank %s\n",
	port->bgc.gc.of_node->full_name);
	return;
	}

	gpio->domain = irq_domain_add_linear(node, ngpio,
	&irq_generic_chip_ops, gpio);
	if (!gpio->domain)
	return;

	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1,
	"gpio-dwapb", handle_level_irq,
	IRQ_NOREQUEST, 0,
	IRQ_GC_INIT_NESTED_LOCK);
	if (err) {
	dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n");
	irq_domain_remove(gpio->domain);
	gpio->domain = NULL;
	return;
	}

	irq_gc = irq_get_domain_generic_chip(gpio->domain, 0);
	if (!irq_gc) {
	irq_domain_remove(gpio->domain);
	gpio->domain = NULL;
	return;
	}

	irq_gc->reg_base = gpio->regs;
	irq_gc->private = gpio;

	ct = irq_gc->chip_types;
	ct->chip.irq_ack = irq_gc_ack_set_bit;
	ct->chip.irq_mask = irq_gc_mask_set_bit;
	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
	ct->chip.irq_set_type = dwapb_irq_set_type;
	ct->chip.irq_enable = dwapb_irq_enable;
	ct->chip.irq_disable = dwapb_irq_disable;
	ct->chip.irq_request_resources = dwapb_irq_reqres;
	ct->chip.irq_release_resources = dwapb_irq_relres;
	ct->regs.ack = GPIO_PORTA_EOI;
	ct->regs.mask = GPIO_INTMASK;

	irq_setup_generic_chip(irq_gc, IRQ_MSK(port->bgc.gc.ngpio),
	IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);

	irq_set_chained_handler(irq, dwapb_irq_handler);
	irq_set_handler_data(irq, gpio);

	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
	irq_create_mapping(gpio->domain, hwirq);

	port->bgc.gc.to_irq = dwapb_gpio_to_irq;
	}

	static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
	{
	struct dwapb_gpio_port *port = &gpio->ports[0];
	struct gpio_chip *gc = &port->bgc.gc;
	unsigned int ngpio = gc->ngpio;
	irq_hw_number_t hwirq;

	if (!gpio->domain)
	return;

	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
	irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq));

	irq_domain_remove(gpio->domain);
	gpio->domain = NULL;
	}

	static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
	struct device_node *port_np,
	unsigned int offs)
	{
	struct dwapb_gpio_port *port;
	u32 port_idx, ngpio;
	void __iomem dat, set, *dirout;
	int err;

	if (of_property_read_u32(port_np, "reg", &port_idx) \|\|
	port_idx >= DWAPB_MAX_PORTS) {
	dev_err(gpio->dev, "missing/invalid port index for %s\n",
	port_np->full_name);
	return -EINVAL;
	}

	port = &gpio->ports[offs];
	port->gpio = gpio;

	if (of_property_read_u32(port_np, "snps,nr-gpios", &ngpio)) {
	dev_info(gpio->dev, "failed to get number of gpios for %s\n",
	port_np->full_name);
	ngpio = 32;
	}

	dat = gpio->regs + GPIO_EXT_PORTA + (port_idx * GPIO_EXT_PORT_SIZE);
	set = gpio->regs + GPIO_SWPORTA_DR + (port_idx * GPIO_SWPORT_DR_SIZE);
	dirout = gpio->regs + GPIO_SWPORTA_DDR +
	(port_idx * GPIO_SWPORT_DDR_SIZE);

	err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout,
	NULL, false);
	if (err) {
	dev_err(gpio->dev, "failed to init gpio chip for %s\n",
	port_np->full_name);
	return err;
	}

	port->bgc.gc.ngpio = ngpio;
	port->bgc.gc.of_node = port_np;

	/*
	* Only port A can provide interrupts in all configurations of the IP.
	*/
	if (port_idx == 0 &&
	of_property_read_bool(port_np, "interrupt-controller"))
	dwapb_configure_irqs(gpio, port);

	err = gpiochip_add(&port->bgc.gc);
	if (err)
	dev_err(gpio->dev, "failed to register gpiochip for %s\n",
	port_np->full_name);
	else
	port->is_registered = true;

	return err;
	}

	static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
	{
	unsigned int m;

	for (m = 0; m < gpio->nr_ports; ++m)
	if (gpio->ports[m].is_registered)
	WARN_ON(gpiochip_remove(&gpio->ports[m].bgc.gc));
	}

	static int dwapb_gpio_probe(struct platform_device *pdev)
	{
	struct resource *res;
	struct dwapb_gpio *gpio;
	struct device_node *np;
	int err;
	unsigned int offs = 0;

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

	gpio->nr_ports = of_get_child_count(pdev->dev.of_node);
	if (!gpio->nr_ports) {
	err = -EINVAL;
	goto out_err;
	}
	gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports *
	sizeof(*gpio->ports), GFP_KERNEL);
	if (!gpio->ports) {
	err = -ENOMEM;
	goto out_err;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gpio->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(gpio->regs)) {
	err = PTR_ERR(gpio->regs);
	goto out_err;
	}

	for_each_child_of_node(pdev->dev.of_node, np) {
	err = dwapb_gpio_add_port(gpio, np, offs++);
	if (err)
	goto out_unregister;
	}
	platform_set_drvdata(pdev, gpio);

	return 0;

	out_unregister:
	dwapb_gpio_unregister(gpio);
	dwapb_irq_teardown(gpio);

	out_err:
	return err;
	}

	static int dwapb_gpio_remove(struct platform_device *pdev)
	{
	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);

	dwapb_gpio_unregister(gpio);
	dwapb_irq_teardown(gpio);

	return 0;
	}

	static const struct of_device_id dwapb_of_match[] = {
	{ .compatible = "snps,dw-apb-gpio" },
	{ /* Sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, dwapb_of_match);

	static struct platform_driver dwapb_gpio_driver = {
	.driver = {
	.name = "gpio-dwapb",
	.owner = THIS_MODULE,
	.of_match_table = of_match_ptr(dwapb_of_match),
	},
	.probe = dwapb_gpio_probe,
	.remove = dwapb_gpio_remove,
	};

	module_platform_driver(dwapb_gpio_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Jamie Iles");
	MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");