drivers/gpio/gpio-ep93xx.c - kernel/msm-4.19 - Gitiles

 /*
  * 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
  *
  *  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.
  */

 #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>
 /* FIXME: this is here for gpio_to_irq() - get rid of this! */
 #include <linux/gpio.h>

 #include <mach/hardware.h>
 #include <mach/gpio-ep93xx.h>

 #define irq_to_gpio(irq)	((irq) - gpio_to_irq(0))

 struct ep93xx_gpio {
 	void __iomem		*mmio_base;
 	struct gpio_chip	gc[8];
 };

 /*************************************************************************
  * Interrupt handling for EP93xx on-chip GPIOs
  *************************************************************************/
 static unsigned char gpio_int_unmasked[3];
 static unsigned char gpio_int_enabled[3];
 static unsigned char gpio_int_type1[3];
 static unsigned char gpio_int_type2[3];
 static unsigned char gpio_int_debounce[3];

 /* Port ordering is: A B F */
 static const u8 int_type1_register_offset[3]	= { 0x90, 0xac, 0x4c };
 static const u8 int_type2_register_offset[3]	= { 0x94, 0xb0, 0x50 };
 static const u8 eoi_register_offset[3]		= { 0x98, 0xb4, 0x54 };
 static const u8 int_en_register_offset[3]	= { 0x9c, 0xb8, 0x58 };
 static const u8 int_debounce_register_offset[3]	= { 0xa8, 0xc4, 0x64 };

 static void ep93xx_gpio_update_int_params(unsigned port)
 {
 	BUG_ON(port > 2);

 	writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));

 	writeb_relaxed(gpio_int_type2[port],
 		EP93XX_GPIO_REG(int_type2_register_offset[port]));

 	writeb_relaxed(gpio_int_type1[port],
 		EP93XX_GPIO_REG(int_type1_register_offset[port]));

 	writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
 		EP93XX_GPIO_REG(int_en_register_offset[port]));
 }

 static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
 {
 	int line = irq_to_gpio(irq);
 	int port = line >> 3;
 	int port_mask = 1 << (line & 7);

 	if (enable)
 		gpio_int_debounce[port] |= port_mask;
 	else
 		gpio_int_debounce[port] &= ~port_mask;

 	writeb(gpio_int_debounce[port],
 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
 }

 static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
 {
 	unsigned char status;
 	int i;

 	status = readb(EP93XX_GPIO_A_INT_STATUS);
 	for (i = 0; i < 8; i++) {
 		if (status & (1 << i)) {
 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
 			generic_handle_irq(gpio_irq);
 		}
 	}

 	status = readb(EP93XX_GPIO_B_INT_STATUS);
 	for (i = 0; i < 8; i++) {
 		if (status & (1 << i)) {
 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
 			generic_handle_irq(gpio_irq);
 		}
 	}
 }

 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 -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
 	 */
 	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 = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;

 	generic_handle_irq(gpio_irq);
 }

 static void ep93xx_gpio_irq_ack(struct irq_data *d)
 {
 	int line = irq_to_gpio(d->irq);
 	int port = line >> 3;
 	int port_mask = 1 << (line & 7);

 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 		ep93xx_gpio_update_int_params(port);
 	}

 	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 }

 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
 {
 	int line = irq_to_gpio(d->irq);
 	int port = line >> 3;
 	int port_mask = 1 << (line & 7);

 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */

 	gpio_int_unmasked[port] &= ~port_mask;
 	ep93xx_gpio_update_int_params(port);

 	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 }

 static void ep93xx_gpio_irq_mask(struct irq_data *d)
 {
 	int line = irq_to_gpio(d->irq);
 	int port = line >> 3;

 	gpio_int_unmasked[port] &= ~(1 << (line & 7));
 	ep93xx_gpio_update_int_params(port);
 }

 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
 {
 	int line = irq_to_gpio(d->irq);
 	int port = line >> 3;

 	gpio_int_unmasked[port] |= 1 << (line & 7);
 	ep93xx_gpio_update_int_params(port);
 }

 /*
  * 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)
 {
 	const int gpio = irq_to_gpio(d->irq);
 	const int port = gpio >> 3;
 	const int port_mask = 1 << (gpio & 7);
 	irq_flow_handler_t handler;

 	gpio_direction_input(gpio);

 	switch (type) {
 	case IRQ_TYPE_EDGE_RISING:
 		gpio_int_type1[port] |= port_mask;
 		gpio_int_type2[port] |= port_mask;
 		handler = handle_edge_irq;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		gpio_int_type1[port] |= port_mask;
 		gpio_int_type2[port] &= ~port_mask;
 		handler = handle_edge_irq;
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 		gpio_int_type1[port] &= ~port_mask;
 		gpio_int_type2[port] |= port_mask;
 		handler = handle_level_irq;
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		gpio_int_type1[port] &= ~port_mask;
 		gpio_int_type2[port] &= ~port_mask;
 		handler = handle_level_irq;
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
 		gpio_int_type1[port] |= port_mask;
 		/* set initial polarity based on current input level */
 		if (gpio_get_value(gpio))
 			gpio_int_type2[port] &= ~port_mask; /* falling */
 		else
 			gpio_int_type2[port] |= port_mask; /* rising */
 		handler = handle_edge_irq;
 		break;
 	default:
 		return -EINVAL;
 	}

 	irq_set_handler_locked(d, handler);

 	gpio_int_enabled[port] |= port_mask;

 	ep93xx_gpio_update_int_params(port);

 	return 0;
 }

 static struct irq_chip ep93xx_gpio_irq_chip = {
 	.name		= "GPIO",
 	.irq_ack	= ep93xx_gpio_irq_ack,
 	.irq_mask_ack	= ep93xx_gpio_irq_mask_ack,
 	.irq_mask	= ep93xx_gpio_irq_mask,
 	.irq_unmask	= ep93xx_gpio_irq_unmask,
 	.irq_set_type	= ep93xx_gpio_irq_type,
 };

 static void ep93xx_gpio_init_irq(void)
 {
 	int gpio_irq;

 	for (gpio_irq = gpio_to_irq(0);
 	     gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
 		irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
 					 handle_level_irq);
 		irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
 	}

 	irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
 				ep93xx_gpio_ab_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
 				ep93xx_gpio_f_irq_handler);
 	irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
 				ep93xx_gpio_f_irq_handler);
 }


 /*************************************************************************
  * gpiolib interface for EP93xx on-chip GPIOs
  *************************************************************************/
 struct ep93xx_gpio_bank {
 	const char	*label;
 	int		data;
 	int		dir;
 	int		base;
 	bool		has_debounce;
 };

 #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce)	\
 	{							\
 		.label		= _label,			\
 		.data		= _data,			\
 		.dir		= _dir,				\
 		.base		= _base,			\
 		.has_debounce	= _debounce,			\
 	}

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

 static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
 				    unsigned offset, unsigned debounce)
 {
 	int gpio = chip->base + offset;
 	int irq = gpio_to_irq(gpio);

 	if (irq < 0)
 		return -EINVAL;

 	ep93xx_gpio_int_debounce(irq, debounce ? true : false);

 	return 0;
 }

 /*
  * Map GPIO A0..A7  (0..7)  to irq 64..71,
  *          B0..B7  (7..15) to irq 72..79, and
  *          F0..F7 (16..24) to irq 80..87.
  */
 static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	int gpio = chip->base + offset;

 	if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
 		return -EINVAL;

 	return 64 + gpio;
 }

 static int ep93xx_gpio_add_bank(struct gpio_chip *gc, struct device *dev,
 	void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
 {
 	void __iomem *data = mmio_base + bank->data;
 	void __iomem *dir =  mmio_base + bank->dir;
 	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;

 	if (bank->has_debounce) {
 		gc->set_debounce = ep93xx_gpio_set_debounce;
 		gc->to_irq = ep93xx_gpio_to_irq;
 	}

 	return gpiochip_add_data(gc, NULL);
 }

 static int ep93xx_gpio_probe(struct platform_device *pdev)
 {
 	struct ep93xx_gpio *ep93xx_gpio;
 	struct resource *res;
 	int i;
 	struct device *dev = &pdev->dev;

 	ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL);
 	if (!ep93xx_gpio)
 		return -ENOMEM;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ep93xx_gpio->mmio_base))
 		return PTR_ERR(ep93xx_gpio->mmio_base);

 	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
 		struct gpio_chip *gc = &ep93xx_gpio->gc[i];
 		struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];

 		if (ep93xx_gpio_add_bank(gc, &pdev->dev,
 					 ep93xx_gpio->mmio_base, bank))
 			dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
 				bank->label);
 	}

 	ep93xx_gpio_init_irq();

 	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");
	/*
	* 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
	*
	* 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.
	*/

	#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>
	/* FIXME: this is here for gpio_to_irq() - get rid of this! */
	#include <linux/gpio.h>

	#include <mach/hardware.h>
	#include <mach/gpio-ep93xx.h>

	#define irq_to_gpio(irq) ((irq) - gpio_to_irq(0))

	struct ep93xx_gpio {
	void __iomem *mmio_base;
	struct gpio_chip gc[8];
	};

	/*************************************************************************
	* Interrupt handling for EP93xx on-chip GPIOs
	*************************************************************************/
	static unsigned char gpio_int_unmasked[3];
	static unsigned char gpio_int_enabled[3];
	static unsigned char gpio_int_type1[3];
	static unsigned char gpio_int_type2[3];
	static unsigned char gpio_int_debounce[3];

	/* Port ordering is: A B F */
	static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
	static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
	static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
	static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
	static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };

	static void ep93xx_gpio_update_int_params(unsigned port)
	{
	BUG_ON(port > 2);

	writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));

	writeb_relaxed(gpio_int_type2[port],
	EP93XX_GPIO_REG(int_type2_register_offset[port]));

	writeb_relaxed(gpio_int_type1[port],
	EP93XX_GPIO_REG(int_type1_register_offset[port]));

	writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
	EP93XX_GPIO_REG(int_en_register_offset[port]));
	}

	static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
	{
	int line = irq_to_gpio(irq);
	int port = line >> 3;
	int port_mask = 1 << (line & 7);

	if (enable)
	gpio_int_debounce[port] \|= port_mask;
	else
	gpio_int_debounce[port] &= ~port_mask;

	writeb(gpio_int_debounce[port],
	EP93XX_GPIO_REG(int_debounce_register_offset[port]));
	}

	static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
	{
	unsigned char status;
	int i;

	status = readb(EP93XX_GPIO_A_INT_STATUS);
	for (i = 0; i < 8; i++) {
	if (status & (1 << i)) {
	int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
	generic_handle_irq(gpio_irq);
	}
	}

	status = readb(EP93XX_GPIO_B_INT_STATUS);
	for (i = 0; i < 8; i++) {
	if (status & (1 << i)) {
	int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
	generic_handle_irq(gpio_irq);
	}
	}
	}

	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 -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
	*/
	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 = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;

	generic_handle_irq(gpio_irq);
	}

	static void ep93xx_gpio_irq_ack(struct irq_data *d)
	{
	int line = irq_to_gpio(d->irq);
	int port = line >> 3;
	int port_mask = 1 << (line & 7);

	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
	gpio_int_type2[port] ^= port_mask; /* switch edge direction */
	ep93xx_gpio_update_int_params(port);
	}

	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
	}

	static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
	{
	int line = irq_to_gpio(d->irq);
	int port = line >> 3;
	int port_mask = 1 << (line & 7);

	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
	gpio_int_type2[port] ^= port_mask; /* switch edge direction */

	gpio_int_unmasked[port] &= ~port_mask;
	ep93xx_gpio_update_int_params(port);

	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
	}

	static void ep93xx_gpio_irq_mask(struct irq_data *d)
	{
	int line = irq_to_gpio(d->irq);
	int port = line >> 3;

	gpio_int_unmasked[port] &= ~(1 << (line & 7));
	ep93xx_gpio_update_int_params(port);
	}

	static void ep93xx_gpio_irq_unmask(struct irq_data *d)
	{
	int line = irq_to_gpio(d->irq);
	int port = line >> 3;

	gpio_int_unmasked[port] \|= 1 << (line & 7);
	ep93xx_gpio_update_int_params(port);
	}

	/*
	* 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)
	{
	const int gpio = irq_to_gpio(d->irq);
	const int port = gpio >> 3;
	const int port_mask = 1 << (gpio & 7);
	irq_flow_handler_t handler;

	gpio_direction_input(gpio);

	switch (type) {
	case IRQ_TYPE_EDGE_RISING:
	gpio_int_type1[port] \|= port_mask;
	gpio_int_type2[port] \|= port_mask;
	handler = handle_edge_irq;
	break;
	case IRQ_TYPE_EDGE_FALLING:
	gpio_int_type1[port] \|= port_mask;
	gpio_int_type2[port] &= ~port_mask;
	handler = handle_edge_irq;
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	gpio_int_type1[port] &= ~port_mask;
	gpio_int_type2[port] \|= port_mask;
	handler = handle_level_irq;
	break;
	case IRQ_TYPE_LEVEL_LOW:
	gpio_int_type1[port] &= ~port_mask;
	gpio_int_type2[port] &= ~port_mask;
	handler = handle_level_irq;
	break;
	case IRQ_TYPE_EDGE_BOTH:
	gpio_int_type1[port] \|= port_mask;
	/* set initial polarity based on current input level */
	if (gpio_get_value(gpio))
	gpio_int_type2[port] &= ~port_mask; /* falling */
	else
	gpio_int_type2[port] \|= port_mask; /* rising */
	handler = handle_edge_irq;
	break;
	default:
	return -EINVAL;
	}

	irq_set_handler_locked(d, handler);

	gpio_int_enabled[port] \|= port_mask;

	ep93xx_gpio_update_int_params(port);

	return 0;
	}

	static struct irq_chip ep93xx_gpio_irq_chip = {
	.name = "GPIO",
	.irq_ack = ep93xx_gpio_irq_ack,
	.irq_mask_ack = ep93xx_gpio_irq_mask_ack,
	.irq_mask = ep93xx_gpio_irq_mask,
	.irq_unmask = ep93xx_gpio_irq_unmask,
	.irq_set_type = ep93xx_gpio_irq_type,
	};

	static void ep93xx_gpio_init_irq(void)
	{
	int gpio_irq;

	for (gpio_irq = gpio_to_irq(0);
	gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
	irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
	handle_level_irq);
	irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
	}

	irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
	ep93xx_gpio_ab_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
	ep93xx_gpio_f_irq_handler);
	irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
	ep93xx_gpio_f_irq_handler);
	}


	/*************************************************************************
	* gpiolib interface for EP93xx on-chip GPIOs
	*************************************************************************/
	struct ep93xx_gpio_bank {
	const char *label;
	int data;
	int dir;
	int base;
	bool has_debounce;
	};

	#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
	{ \
	.label = _label, \
	.data = _data, \
	.dir = _dir, \
	.base = _base, \
	.has_debounce = _debounce, \
	}

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

	static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
	unsigned offset, unsigned debounce)
	{
	int gpio = chip->base + offset;
	int irq = gpio_to_irq(gpio);

	if (irq < 0)
	return -EINVAL;

	ep93xx_gpio_int_debounce(irq, debounce ? true : false);

	return 0;
	}

	/*
	* Map GPIO A0..A7 (0..7) to irq 64..71,
	* B0..B7 (7..15) to irq 72..79, and
	* F0..F7 (16..24) to irq 80..87.
	*/
	static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
	{
	int gpio = chip->base + offset;

	if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
	return -EINVAL;

	return 64 + gpio;
	}

	static int ep93xx_gpio_add_bank(struct gpio_chip gc, struct device dev,
	void __iomem mmio_base, struct ep93xx_gpio_bank bank)
	{
	void __iomem *data = mmio_base + bank->data;
	void __iomem *dir = mmio_base + bank->dir;
	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;

	if (bank->has_debounce) {
	gc->set_debounce = ep93xx_gpio_set_debounce;
	gc->to_irq = ep93xx_gpio_to_irq;
	}

	return gpiochip_add_data(gc, NULL);
	}

	static int ep93xx_gpio_probe(struct platform_device *pdev)
	{
	struct ep93xx_gpio *ep93xx_gpio;
	struct resource *res;
	int i;
	struct device *dev = &pdev->dev;

	ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL);
	if (!ep93xx_gpio)
	return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(ep93xx_gpio->mmio_base))
	return PTR_ERR(ep93xx_gpio->mmio_base);

	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
	struct gpio_chip *gc = &ep93xx_gpio->gc[i];
	struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];

	if (ep93xx_gpio_add_bank(gc, &pdev->dev,
	ep93xx_gpio->mmio_base, bank))
	dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
	bank->label);
	}

	ep93xx_gpio_init_irq();

	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");