drivers/gpio/gpio-ep93xx.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Generic EP93xx GPIO handling
  *
  * Copyright (c) 2008 Ryan Mallon
  * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
  *
  * Based on code originally from:
  *  linux/arch/arm/mach-ep93xx/core.c
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
 #include <linux/gpio/driver.h>
 #include <linux/bitops.h>

 #define EP93XX_GPIO_F_INT_STATUS 0x5c
 #define EP93XX_GPIO_A_INT_STATUS 0xa0
 #define EP93XX_GPIO_B_INT_STATUS 0xbc

 /* Maximum value for gpio line identifiers */
 #define EP93XX_GPIO_LINE_MAX 63

 /* Number of GPIO chips in EP93XX */
 #define EP93XX_GPIO_CHIP_NUM 8

 /* Maximum value for irq capable line identifiers */
 #define EP93XX_GPIO_LINE_MAX_IRQ 23

 #define EP93XX_GPIO_A_IRQ_BASE 64
 #define EP93XX_GPIO_B_IRQ_BASE 72
 /*
  * Static mapping of GPIO bank F IRQS:
  * F0..F7 (16..24) to irq 80..87.
  */
 #define EP93XX_GPIO_F_IRQ_BASE 80

 struct ep93xx_gpio_irq_chip {
 	struct irq_chip ic;
 	u8 irq_offset;
 	u8 int_unmasked;
 	u8 int_enabled;
 	u8 int_type1;
 	u8 int_type2;
 	u8 int_debounce;
 };

 struct ep93xx_gpio_chip {
 	struct gpio_chip		gc;
 	struct ep93xx_gpio_irq_chip	*eic;
 };

 struct ep93xx_gpio {
 	void __iomem		*base;
 	struct ep93xx_gpio_chip	gc[EP93XX_GPIO_CHIP_NUM];
 };

 #define to_ep93xx_gpio_chip(x) container_of(x, struct ep93xx_gpio_chip, gc)

 static struct ep93xx_gpio_irq_chip *to_ep93xx_gpio_irq_chip(struct gpio_chip *gc)
 {
 	struct ep93xx_gpio_chip *egc = to_ep93xx_gpio_chip(gc);

 	return egc->eic;
 }

 /*************************************************************************
  * Interrupt handling for EP93xx on-chip GPIOs
  *************************************************************************/
 #define EP93XX_INT_TYPE1_OFFSET		0x00
 #define EP93XX_INT_TYPE2_OFFSET		0x04
 #define EP93XX_INT_EOI_OFFSET		0x08
 #define EP93XX_INT_EN_OFFSET		0x0c
 #define EP93XX_INT_STATUS_OFFSET	0x10
 #define EP93XX_INT_RAW_STATUS_OFFSET	0x14
 #define EP93XX_INT_DEBOUNCE_OFFSET	0x18

 static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg,
 					  struct ep93xx_gpio_irq_chip *eic)
 {
 	writeb_relaxed(0, epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);

 	writeb_relaxed(eic->int_type2,
 		       epg->base + eic->irq_offset + EP93XX_INT_TYPE2_OFFSET);

 	writeb_relaxed(eic->int_type1,
 		       epg->base + eic->irq_offset + EP93XX_INT_TYPE1_OFFSET);

 	writeb_relaxed(eic->int_unmasked & eic->int_enabled,
 		       epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);
 }

 static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
 				     unsigned int offset, bool enable)
 {
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	int port_mask = BIT(offset);

 	if (enable)
 		eic->int_debounce |= port_mask;
 	else
 		eic->int_debounce &= ~port_mask;

 	writeb(eic->int_debounce,
 	       epg->base + eic->irq_offset + EP93XX_INT_DEBOUNCE_OFFSET);
 }

 static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
 {
 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
 	unsigned long stat;
 	int offset;

 	chained_irq_enter(irqchip, desc);

 	/*
 	 * Dispatch the IRQs to the irqdomain of each A and B
 	 * gpiochip irqdomains depending on what has fired.
 	 * The tricky part is that the IRQ line is shared
 	 * between bank A and B and each has their own gpiochip.
 	 */
 	stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
 	for_each_set_bit(offset, &stat, 8)
 		generic_handle_domain_irq(epg->gc[0].gc.irq.domain,
 					  offset);

 	stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
 	for_each_set_bit(offset, &stat, 8)
 		generic_handle_domain_irq(epg->gc[1].gc.irq.domain,
 					  offset);

 	chained_irq_exit(irqchip, desc);
 }

 static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
 {
 	/*
 	 * map discontiguous hw irq range to continuous sw irq range:
 	 *
 	 *  IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
 	 */
 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
 	unsigned int irq = irq_desc_get_irq(desc);
 	int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
 	int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;

 	chained_irq_enter(irqchip, desc);
 	generic_handle_irq(gpio_irq);
 	chained_irq_exit(irqchip, desc);
 }

 static void ep93xx_gpio_irq_ack(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 	int port_mask = BIT(d->irq & 7);

 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
 		eic->int_type2 ^= port_mask; /* switch edge direction */
 		ep93xx_gpio_update_int_params(epg, eic);
 	}

 	writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
 }

 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 	int port_mask = BIT(d->irq & 7);

 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
 		eic->int_type2 ^= port_mask; /* switch edge direction */

 	eic->int_unmasked &= ~port_mask;
 	ep93xx_gpio_update_int_params(epg, eic);

 	writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
 }

 static void ep93xx_gpio_irq_mask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);

 	eic->int_unmasked &= ~BIT(d->irq & 7);
 	ep93xx_gpio_update_int_params(epg, eic);
 }

 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);

 	eic->int_unmasked |= BIT(d->irq & 7);
 	ep93xx_gpio_update_int_params(epg, eic);
 }

 /*
  * gpio_int_type1 controls whether the interrupt is level (0) or
  * edge (1) triggered, while gpio_int_type2 controls whether it
  * triggers on low/falling (0) or high/rising (1).
  */
 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
 	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 	int offset = d->irq & 7;
 	int port_mask = BIT(offset);
 	irq_flow_handler_t handler;

 	gc->direction_input(gc, offset);

 	switch (type) {
 	case IRQ_TYPE_EDGE_RISING:
 		eic->int_type1 |= port_mask;
 		eic->int_type2 |= port_mask;
 		handler = handle_edge_irq;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		eic->int_type1 |= port_mask;
 		eic->int_type2 &= ~port_mask;
 		handler = handle_edge_irq;
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 		eic->int_type1 &= ~port_mask;
 		eic->int_type2 |= port_mask;
 		handler = handle_level_irq;
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		eic->int_type1 &= ~port_mask;
 		eic->int_type2 &= ~port_mask;
 		handler = handle_level_irq;
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
 		eic->int_type1 |= port_mask;
 		/* set initial polarity based on current input level */
 		if (gc->get(gc, offset))
 			eic->int_type2 &= ~port_mask; /* falling */
 		else
 			eic->int_type2 |= port_mask; /* rising */
 		handler = handle_edge_irq;
 		break;
 	default:
 		return -EINVAL;
 	}

 	irq_set_handler_locked(d, handler);

 	eic->int_enabled |= port_mask;

 	ep93xx_gpio_update_int_params(epg, eic);

 	return 0;
 }

 /*************************************************************************
  * gpiolib interface for EP93xx on-chip GPIOs
  *************************************************************************/
 struct ep93xx_gpio_bank {
 	const char	*label;
 	int		data;
 	int		dir;
 	int		irq;
 	int		base;
 	bool		has_irq;
 	bool		has_hierarchical_irq;
 	unsigned int	irq_base;
 };

 #define EP93XX_GPIO_BANK(_label, _data, _dir, _irq, _base, _has_irq, _has_hier, _irq_base) \
 	{							\
 		.label		= _label,			\
 		.data		= _data,			\
 		.dir		= _dir,				\
 		.irq		= _irq,				\
 		.base		= _base,			\
 		.has_irq	= _has_irq,			\
 		.has_hierarchical_irq = _has_hier,		\
 		.irq_base	= _irq_base,			\
 	}

 static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
 	/* Bank A has 8 IRQs */
 	EP93XX_GPIO_BANK("A", 0x00, 0x10, 0x90, 0, true, false, EP93XX_GPIO_A_IRQ_BASE),
 	/* Bank B has 8 IRQs */
 	EP93XX_GPIO_BANK("B", 0x04, 0x14, 0xac, 8, true, false, EP93XX_GPIO_B_IRQ_BASE),
 	EP93XX_GPIO_BANK("C", 0x08, 0x18, 0x00, 40, false, false, 0),
 	EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 0x00, 24, false, false, 0),
 	EP93XX_GPIO_BANK("E", 0x20, 0x24, 0x00, 32, false, false, 0),
 	/* Bank F has 8 IRQs */
 	EP93XX_GPIO_BANK("F", 0x30, 0x34, 0x4c, 16, false, true, EP93XX_GPIO_F_IRQ_BASE),
 	EP93XX_GPIO_BANK("G", 0x38, 0x3c, 0x00, 48, false, false, 0),
 	EP93XX_GPIO_BANK("H", 0x40, 0x44, 0x00, 56, false, false, 0),
 };

 static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
 				  unsigned long config)
 {
 	u32 debounce;

 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
 		return -ENOTSUPP;

 	debounce = pinconf_to_config_argument(config);
 	ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);

 	return 0;
 }

 static void ep93xx_init_irq_chip(struct device *dev, struct irq_chip *ic)
 {
 	ic->irq_ack = ep93xx_gpio_irq_ack;
 	ic->irq_mask_ack = ep93xx_gpio_irq_mask_ack;
 	ic->irq_mask = ep93xx_gpio_irq_mask;
 	ic->irq_unmask = ep93xx_gpio_irq_unmask;
 	ic->irq_set_type = ep93xx_gpio_irq_type;
 }

 static int ep93xx_gpio_add_bank(struct ep93xx_gpio_chip *egc,
 				struct platform_device *pdev,
 				struct ep93xx_gpio *epg,
 				struct ep93xx_gpio_bank *bank)
 {
 	void __iomem *data = epg->base + bank->data;
 	void __iomem *dir = epg->base + bank->dir;
 	struct gpio_chip *gc = &egc->gc;
 	struct device *dev = &pdev->dev;
 	struct gpio_irq_chip *girq;
 	int err;

 	err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
 	if (err)
 		return err;

 	gc->label = bank->label;
 	gc->base = bank->base;

 	girq = &gc->irq;
 	if (bank->has_irq || bank->has_hierarchical_irq) {
 		struct irq_chip *ic;

 		gc->set_config = ep93xx_gpio_set_config;
 		egc->eic = devm_kcalloc(dev, 1,
 					sizeof(*egc->eic),
 					GFP_KERNEL);
 		if (!egc->eic)
 			return -ENOMEM;
 		egc->eic->irq_offset = bank->irq;
 		ic = &egc->eic->ic;
 		ic->name = devm_kasprintf(dev, GFP_KERNEL, "gpio-irq-%s", bank->label);
 		if (!ic->name)
 			return -ENOMEM;
 		ep93xx_init_irq_chip(dev, ic);
 		girq->chip = ic;
 	}

 	if (bank->has_irq) {
 		int ab_parent_irq = platform_get_irq(pdev, 0);

 		girq->parent_handler = ep93xx_gpio_ab_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->default_type = IRQ_TYPE_NONE;
 		girq->handler = handle_level_irq;
 		girq->parents[0] = ab_parent_irq;
 		girq->first = bank->irq_base;
 	}

 	/* Only bank F has especially funky IRQ handling */
 	if (bank->has_hierarchical_irq) {
 		int gpio_irq;
 		int i;

 		/*
 		 * FIXME: convert this to use hierarchical IRQ support!
 		 * this requires fixing the root irqchip to be hierarchical.
 		 */
 		girq->parent_handler = ep93xx_gpio_f_irq_handler;
 		girq->num_parents = 8;
 		girq->parents = devm_kcalloc(dev, girq->num_parents,
 					     sizeof(*girq->parents),
 					     GFP_KERNEL);
 		if (!girq->parents)
 			return -ENOMEM;
 		/* Pick resources 1..8 for these IRQs */
 		for (i = 0; i < girq->num_parents; i++) {
 			girq->parents[i] = platform_get_irq(pdev, i + 1);
 			gpio_irq = bank->irq_base + i;
 			irq_set_chip_data(gpio_irq, &epg->gc[5]);
 			irq_set_chip_and_handler(gpio_irq,
 						 girq->chip,
 						 handle_level_irq);
 			irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
 		}
 		girq->default_type = IRQ_TYPE_NONE;
 		girq->handler = handle_level_irq;
 		girq->first = bank->irq_base;
 	}

 	return devm_gpiochip_add_data(dev, gc, epg);
 }

 static int ep93xx_gpio_probe(struct platform_device *pdev)
 {
 	struct ep93xx_gpio *epg;
 	int i;

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

 	epg->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(epg->base))
 		return PTR_ERR(epg->base);

 	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
 		struct ep93xx_gpio_chip *gc = &epg->gc[i];
 		struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];

 		if (ep93xx_gpio_add_bank(gc, pdev, epg, bank))
 			dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
 				 bank->label);
 	}

 	return 0;
 }

 static struct platform_driver ep93xx_gpio_driver = {
 	.driver		= {
 		.name	= "gpio-ep93xx",
 	},
 	.probe		= ep93xx_gpio_probe,
 };

 static int __init ep93xx_gpio_init(void)
 {
 	return platform_driver_register(&ep93xx_gpio_driver);
 }
 postcore_initcall(ep93xx_gpio_init);

 MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
 		"H Hartley Sweeten <hsweeten@visionengravers.com>");
 MODULE_DESCRIPTION("EP93XX GPIO driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Generic EP93xx GPIO handling
	*
	* Copyright (c) 2008 Ryan Mallon
	* Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
	*
	* Based on code originally from:
	* linux/arch/arm/mach-ep93xx/core.c
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/slab.h>
	#include <linux/gpio/driver.h>
	#include <linux/bitops.h>

	#define EP93XX_GPIO_F_INT_STATUS 0x5c
	#define EP93XX_GPIO_A_INT_STATUS 0xa0
	#define EP93XX_GPIO_B_INT_STATUS 0xbc

	/* Maximum value for gpio line identifiers */
	#define EP93XX_GPIO_LINE_MAX 63

	/* Number of GPIO chips in EP93XX */
	#define EP93XX_GPIO_CHIP_NUM 8

	/* Maximum value for irq capable line identifiers */
	#define EP93XX_GPIO_LINE_MAX_IRQ 23

	#define EP93XX_GPIO_A_IRQ_BASE 64
	#define EP93XX_GPIO_B_IRQ_BASE 72
	/*
	* Static mapping of GPIO bank F IRQS:
	* F0..F7 (16..24) to irq 80..87.
	*/
	#define EP93XX_GPIO_F_IRQ_BASE 80

	struct ep93xx_gpio_irq_chip {
	struct irq_chip ic;
	u8 irq_offset;
	u8 int_unmasked;
	u8 int_enabled;
	u8 int_type1;
	u8 int_type2;
	u8 int_debounce;
	};

	struct ep93xx_gpio_chip {
	struct gpio_chip gc;
	struct ep93xx_gpio_irq_chip *eic;
	};

	struct ep93xx_gpio {
	void __iomem *base;
	struct ep93xx_gpio_chip gc[EP93XX_GPIO_CHIP_NUM];
	};

	#define to_ep93xx_gpio_chip(x) container_of(x, struct ep93xx_gpio_chip, gc)

	static struct ep93xx_gpio_irq_chip to_ep93xx_gpio_irq_chip(struct gpio_chip gc)
	{
	struct ep93xx_gpio_chip *egc = to_ep93xx_gpio_chip(gc);

	return egc->eic;
	}

	/*************************************************************************
	* Interrupt handling for EP93xx on-chip GPIOs
	*************************************************************************/
	#define EP93XX_INT_TYPE1_OFFSET 0x00
	#define EP93XX_INT_TYPE2_OFFSET 0x04
	#define EP93XX_INT_EOI_OFFSET 0x08
	#define EP93XX_INT_EN_OFFSET 0x0c
	#define EP93XX_INT_STATUS_OFFSET 0x10
	#define EP93XX_INT_RAW_STATUS_OFFSET 0x14
	#define EP93XX_INT_DEBOUNCE_OFFSET 0x18

	static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg,
	struct ep93xx_gpio_irq_chip *eic)
	{
	writeb_relaxed(0, epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);

	writeb_relaxed(eic->int_type2,
	epg->base + eic->irq_offset + EP93XX_INT_TYPE2_OFFSET);

	writeb_relaxed(eic->int_type1,
	epg->base + eic->irq_offset + EP93XX_INT_TYPE1_OFFSET);

	writeb_relaxed(eic->int_unmasked & eic->int_enabled,
	epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);
	}

	static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
	unsigned int offset, bool enable)
	{
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	int port_mask = BIT(offset);

	if (enable)
	eic->int_debounce \|= port_mask;
	else
	eic->int_debounce &= ~port_mask;

	writeb(eic->int_debounce,
	epg->base + eic->irq_offset + EP93XX_INT_DEBOUNCE_OFFSET);
	}

	static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
	{
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);
	unsigned long stat;
	int offset;

	chained_irq_enter(irqchip, desc);

	/*
	* Dispatch the IRQs to the irqdomain of each A and B
	* gpiochip irqdomains depending on what has fired.
	* The tricky part is that the IRQ line is shared
	* between bank A and B and each has their own gpiochip.
	*/
	stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
	for_each_set_bit(offset, &stat, 8)
	generic_handle_domain_irq(epg->gc[0].gc.irq.domain,
	offset);

	stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
	for_each_set_bit(offset, &stat, 8)
	generic_handle_domain_irq(epg->gc[1].gc.irq.domain,
	offset);

	chained_irq_exit(irqchip, desc);
	}

	static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
	{
	/*
	* map discontiguous hw irq range to continuous sw irq range:
	*
	* IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
	*/
	struct irq_chip *irqchip = irq_desc_get_chip(desc);
	unsigned int irq = irq_desc_get_irq(desc);
	int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
	int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;

	chained_irq_enter(irqchip, desc);
	generic_handle_irq(gpio_irq);
	chained_irq_exit(irqchip, desc);
	}

	static void ep93xx_gpio_irq_ack(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
	int port_mask = BIT(d->irq & 7);

	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
	eic->int_type2 ^= port_mask; /* switch edge direction */
	ep93xx_gpio_update_int_params(epg, eic);
	}

	writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
	}

	static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
	int port_mask = BIT(d->irq & 7);

	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
	eic->int_type2 ^= port_mask; /* switch edge direction */

	eic->int_unmasked &= ~port_mask;
	ep93xx_gpio_update_int_params(epg, eic);

	writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
	}

	static void ep93xx_gpio_irq_mask(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);

	eic->int_unmasked &= ~BIT(d->irq & 7);
	ep93xx_gpio_update_int_params(epg, eic);
	}

	static void ep93xx_gpio_irq_unmask(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);

	eic->int_unmasked \|= BIT(d->irq & 7);
	ep93xx_gpio_update_int_params(epg, eic);
	}

	/*
	* gpio_int_type1 controls whether the interrupt is level (0) or
	* edge (1) triggered, while gpio_int_type2 controls whether it
	* triggers on low/falling (0) or high/rising (1).
	*/
	static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
	struct ep93xx_gpio *epg = gpiochip_get_data(gc);
	int offset = d->irq & 7;
	int port_mask = BIT(offset);
	irq_flow_handler_t handler;

	gc->direction_input(gc, offset);

	switch (type) {
	case IRQ_TYPE_EDGE_RISING:
	eic->int_type1 \|= port_mask;
	eic->int_type2 \|= port_mask;
	handler = handle_edge_irq;
	break;
	case IRQ_TYPE_EDGE_FALLING:
	eic->int_type1 \|= port_mask;
	eic->int_type2 &= ~port_mask;
	handler = handle_edge_irq;
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	eic->int_type1 &= ~port_mask;
	eic->int_type2 \|= port_mask;
	handler = handle_level_irq;
	break;
	case IRQ_TYPE_LEVEL_LOW:
	eic->int_type1 &= ~port_mask;
	eic->int_type2 &= ~port_mask;
	handler = handle_level_irq;
	break;
	case IRQ_TYPE_EDGE_BOTH:
	eic->int_type1 \|= port_mask;
	/* set initial polarity based on current input level */
	if (gc->get(gc, offset))
	eic->int_type2 &= ~port_mask; /* falling */
	else
	eic->int_type2 \|= port_mask; /* rising */
	handler = handle_edge_irq;
	break;
	default:
	return -EINVAL;
	}

	irq_set_handler_locked(d, handler);

	eic->int_enabled \|= port_mask;

	ep93xx_gpio_update_int_params(epg, eic);

	return 0;
	}

	/*************************************************************************
	* gpiolib interface for EP93xx on-chip GPIOs
	*************************************************************************/
	struct ep93xx_gpio_bank {
	const char *label;
	int data;
	int dir;
	int irq;
	int base;
	bool has_irq;
	bool has_hierarchical_irq;
	unsigned int irq_base;
	};

	#define EP93XX_GPIO_BANK(_label, _data, _dir, _irq, _base, _has_irq, _has_hier, _irq_base) \
	{ \
	.label = _label, \
	.data = _data, \
	.dir = _dir, \
	.irq = _irq, \
	.base = _base, \
	.has_irq = _has_irq, \
	.has_hierarchical_irq = _has_hier, \
	.irq_base = _irq_base, \
	}

	static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
	/* Bank A has 8 IRQs */
	EP93XX_GPIO_BANK("A", 0x00, 0x10, 0x90, 0, true, false, EP93XX_GPIO_A_IRQ_BASE),
	/* Bank B has 8 IRQs */
	EP93XX_GPIO_BANK("B", 0x04, 0x14, 0xac, 8, true, false, EP93XX_GPIO_B_IRQ_BASE),
	EP93XX_GPIO_BANK("C", 0x08, 0x18, 0x00, 40, false, false, 0),
	EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 0x00, 24, false, false, 0),
	EP93XX_GPIO_BANK("E", 0x20, 0x24, 0x00, 32, false, false, 0),
	/* Bank F has 8 IRQs */
	EP93XX_GPIO_BANK("F", 0x30, 0x34, 0x4c, 16, false, true, EP93XX_GPIO_F_IRQ_BASE),
	EP93XX_GPIO_BANK("G", 0x38, 0x3c, 0x00, 48, false, false, 0),
	EP93XX_GPIO_BANK("H", 0x40, 0x44, 0x00, 56, false, false, 0),
	};

	static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
	unsigned long config)
	{
	u32 debounce;

	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
	return -ENOTSUPP;

	debounce = pinconf_to_config_argument(config);
	ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);

	return 0;
	}

	static void ep93xx_init_irq_chip(struct device dev, struct irq_chip ic)
	{
	ic->irq_ack = ep93xx_gpio_irq_ack;
	ic->irq_mask_ack = ep93xx_gpio_irq_mask_ack;
	ic->irq_mask = ep93xx_gpio_irq_mask;
	ic->irq_unmask = ep93xx_gpio_irq_unmask;
	ic->irq_set_type = ep93xx_gpio_irq_type;
	}

	static int ep93xx_gpio_add_bank(struct ep93xx_gpio_chip *egc,
	struct platform_device *pdev,
	struct ep93xx_gpio *epg,
	struct ep93xx_gpio_bank *bank)
	{
	void __iomem *data = epg->base + bank->data;
	void __iomem *dir = epg->base + bank->dir;
	struct gpio_chip *gc = &egc->gc;
	struct device *dev = &pdev->dev;
	struct gpio_irq_chip *girq;
	int err;

	err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
	if (err)
	return err;

	gc->label = bank->label;
	gc->base = bank->base;

	girq = &gc->irq;
	if (bank->has_irq \|\| bank->has_hierarchical_irq) {
	struct irq_chip *ic;

	gc->set_config = ep93xx_gpio_set_config;
	egc->eic = devm_kcalloc(dev, 1,
	sizeof(*egc->eic),
	GFP_KERNEL);
	if (!egc->eic)
	return -ENOMEM;
	egc->eic->irq_offset = bank->irq;
	ic = &egc->eic->ic;
	ic->name = devm_kasprintf(dev, GFP_KERNEL, "gpio-irq-%s", bank->label);
	if (!ic->name)
	return -ENOMEM;
	ep93xx_init_irq_chip(dev, ic);
	girq->chip = ic;
	}

	if (bank->has_irq) {
	int ab_parent_irq = platform_get_irq(pdev, 0);

	girq->parent_handler = ep93xx_gpio_ab_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->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_level_irq;
	girq->parents[0] = ab_parent_irq;
	girq->first = bank->irq_base;
	}

	/* Only bank F has especially funky IRQ handling */
	if (bank->has_hierarchical_irq) {
	int gpio_irq;
	int i;

	/*
	* FIXME: convert this to use hierarchical IRQ support!
	* this requires fixing the root irqchip to be hierarchical.
	*/
	girq->parent_handler = ep93xx_gpio_f_irq_handler;
	girq->num_parents = 8;
	girq->parents = devm_kcalloc(dev, girq->num_parents,
	sizeof(*girq->parents),
	GFP_KERNEL);
	if (!girq->parents)
	return -ENOMEM;
	/* Pick resources 1..8 for these IRQs */
	for (i = 0; i < girq->num_parents; i++) {
	girq->parents[i] = platform_get_irq(pdev, i + 1);
	gpio_irq = bank->irq_base + i;
	irq_set_chip_data(gpio_irq, &epg->gc[5]);
	irq_set_chip_and_handler(gpio_irq,
	girq->chip,
	handle_level_irq);
	irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
	}
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_level_irq;
	girq->first = bank->irq_base;
	}

	return devm_gpiochip_add_data(dev, gc, epg);
	}

	static int ep93xx_gpio_probe(struct platform_device *pdev)
	{
	struct ep93xx_gpio *epg;
	int i;

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

	epg->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(epg->base))
	return PTR_ERR(epg->base);

	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
	struct ep93xx_gpio_chip *gc = &epg->gc[i];
	struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];

	if (ep93xx_gpio_add_bank(gc, pdev, epg, bank))
	dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
	bank->label);
	}

	return 0;
	}

	static struct platform_driver ep93xx_gpio_driver = {
	.driver = {
	.name = "gpio-ep93xx",
	},
	.probe = ep93xx_gpio_probe,
	};

	static int __init ep93xx_gpio_init(void)
	{
	return platform_driver_register(&ep93xx_gpio_driver);
	}
	postcore_initcall(ep93xx_gpio_init);

	MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
	"H Hartley Sweeten <hsweeten@visionengravers.com>");
	MODULE_DESCRIPTION("EP93XX GPIO driver");
	MODULE_LICENSE("GPL");