drivers/gpio/gpio-sta2x11.c - kernel/msm-4.19 - Gitiles

 /*
  * STMicroelectronics ConneXt (STA2X11) GPIO driver
  *
  * Copyright 2012 ST Microelectronics (Alessandro Rubini)
  * Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
  * Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
  *
  * 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.
  *
  * 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, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  */

 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/sta2x11-mfd.h>

 struct gsta_regs {
 	u32 dat;		/* 0x00 */
 	u32 dats;
 	u32 datc;
 	u32 pdis;
 	u32 dir;		/* 0x10 */
 	u32 dirs;
 	u32 dirc;
 	u32 unused_1c;
 	u32 afsela;		/* 0x20 */
 	u32 unused_24[7];
 	u32 rimsc;		/* 0x40 */
 	u32 fimsc;
 	u32 is;
 	u32 ic;
 };

 struct gsta_gpio {
 	spinlock_t			lock;
 	struct device			*dev;
 	void __iomem			*reg_base;
 	struct gsta_regs __iomem	*regs[GSTA_NR_BLOCKS];
 	struct gpio_chip		gpio;
 	int				irq_base;
 	/* FIXME: save the whole config here (AF, ...) */
 	unsigned			irq_type[GSTA_NR_GPIO];
 };

 static inline struct gsta_regs __iomem *__regs(struct gsta_gpio *chip, int nr)
 {
 	return chip->regs[nr / GSTA_GPIO_PER_BLOCK];
 }

 static inline u32 __bit(int nr)
 {
 	return 1U << (nr % GSTA_GPIO_PER_BLOCK);
 }

 /*
  * gpio methods
  */

 static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 {
 	struct gsta_gpio *chip = gpiochip_get_data(gpio);
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);

 	if (val)
 		writel(bit, &regs->dats);
 	else
 		writel(bit, &regs->datc);
 }

 static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
 {
 	struct gsta_gpio *chip = gpiochip_get_data(gpio);
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);

 	return !!(readl(&regs->dat) & bit);
 }

 static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 				      int val)
 {
 	struct gsta_gpio *chip = gpiochip_get_data(gpio);
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);

 	writel(bit, &regs->dirs);
 	/* Data register after direction, otherwise pullup/down is selected */
 	if (val)
 		writel(bit, &regs->dats);
 	else
 		writel(bit, &regs->datc);
 	return 0;
 }

 static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
 {
 	struct gsta_gpio *chip = gpiochip_get_data(gpio);
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);

 	writel(bit, &regs->dirc);
 	return 0;
 }

 static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
 {
 	struct gsta_gpio *chip = gpiochip_get_data(gpio);
 	return chip->irq_base + offset;
 }

 static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */
 {
 	struct gpio_chip *gpio = &chip->gpio;

 	/*
 	 * ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
 	 * from the end. However, for compatibility, we need the first
 	 * ConneXt device to start from gpio 0: it's the main chipset
 	 * on most boards so documents and drivers assume gpio0..gpio127
 	 */
 	static int gpio_base;

 	gpio->label = dev_name(chip->dev);
 	gpio->owner = THIS_MODULE;
 	gpio->direction_input = gsta_gpio_direction_input;
 	gpio->get = gsta_gpio_get;
 	gpio->direction_output = gsta_gpio_direction_output;
 	gpio->set = gsta_gpio_set;
 	gpio->dbg_show = NULL;
 	gpio->base = gpio_base;
 	gpio->ngpio = GSTA_NR_GPIO;
 	gpio->can_sleep = false;
 	gpio->to_irq = gsta_gpio_to_irq;

 	/*
 	 * After the first device, turn to dynamic gpio numbers.
 	 * For example, with ARCH_NR_GPIOS = 256 we can fit two cards
 	 */
 	if (!gpio_base)
 		gpio_base = -1;
 }

 /*
  * Special method: alternate functions and pullup/pulldown. This is only
  * invoked on startup to configure gpio's according to platform data.
  * FIXME : this functionality shall be managed (and exported to other drivers)
  * via the pin control subsystem.
  */
 static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
 {
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	unsigned long flags;
 	u32 bit = __bit(nr);
 	u32 val;
 	int err = 0;

 	pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg);

 	if (cfg == PINMUX_TYPE_NONE)
 		return;

 	/* Alternate function or not? */
 	spin_lock_irqsave(&chip->lock, flags);
 	val = readl(&regs->afsela);
 	if (cfg == PINMUX_TYPE_FUNCTION)
 		val |= bit;
 	else
 		val &= ~bit;
 	writel(val | bit, &regs->afsela);
 	if (cfg == PINMUX_TYPE_FUNCTION) {
 		spin_unlock_irqrestore(&chip->lock, flags);
 		return;
 	}

 	/* not alternate function: set details */
 	switch (cfg) {
 	case PINMUX_TYPE_OUTPUT_LOW:
 		writel(bit, &regs->dirs);
 		writel(bit, &regs->datc);
 		break;
 	case PINMUX_TYPE_OUTPUT_HIGH:
 		writel(bit, &regs->dirs);
 		writel(bit, &regs->dats);
 		break;
 	case PINMUX_TYPE_INPUT:
 		writel(bit, &regs->dirc);
 		val = readl(&regs->pdis) | bit;
 		writel(val, &regs->pdis);
 		break;
 	case PINMUX_TYPE_INPUT_PULLUP:
 		writel(bit, &regs->dirc);
 		val = readl(&regs->pdis) & ~bit;
 		writel(val, &regs->pdis);
 		writel(bit, &regs->dats);
 		break;
 	case PINMUX_TYPE_INPUT_PULLDOWN:
 		writel(bit, &regs->dirc);
 		val = readl(&regs->pdis) & ~bit;
 		writel(val, &regs->pdis);
 		writel(bit, &regs->datc);
 		break;
 	default:
 		err = 1;
 	}
 	spin_unlock_irqrestore(&chip->lock, flags);
 	if (err)
 		pr_err("%s: chip %p, pin %i, cfg %i is invalid\n",
 		       __func__, chip, nr, cfg);
 }

 /*
  * Irq methods
  */

 static void gsta_irq_disable(struct irq_data *data)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
 	struct gsta_gpio *chip = gc->private;
 	int nr = data->irq - chip->irq_base;
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);
 	u32 val;
 	unsigned long flags;

 	spin_lock_irqsave(&chip->lock, flags);
 	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
 		val = readl(&regs->rimsc) & ~bit;
 		writel(val, &regs->rimsc);
 	}
 	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
 		val = readl(&regs->fimsc) & ~bit;
 		writel(val, &regs->fimsc);
 	}
 	spin_unlock_irqrestore(&chip->lock, flags);
 	return;
 }

 static void gsta_irq_enable(struct irq_data *data)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
 	struct gsta_gpio *chip = gc->private;
 	int nr = data->irq - chip->irq_base;
 	struct gsta_regs __iomem *regs = __regs(chip, nr);
 	u32 bit = __bit(nr);
 	u32 val;
 	int type;
 	unsigned long flags;

 	type = chip->irq_type[nr];

 	spin_lock_irqsave(&chip->lock, flags);
 	val = readl(&regs->rimsc);
 	if (type & IRQ_TYPE_EDGE_RISING)
 		writel(val | bit, &regs->rimsc);
 	else
 		writel(val & ~bit, &regs->rimsc);
 	val = readl(&regs->rimsc);
 	if (type & IRQ_TYPE_EDGE_FALLING)
 		writel(val | bit, &regs->fimsc);
 	else
 		writel(val & ~bit, &regs->fimsc);
 	spin_unlock_irqrestore(&chip->lock, flags);
 	return;
 }

 static int gsta_irq_type(struct irq_data *d, unsigned int type)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct gsta_gpio *chip = gc->private;
 	int nr = d->irq - chip->irq_base;

 	/* We only support edge interrupts */
 	if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) {
 		pr_debug("%s: unsupported type 0x%x\n", __func__, type);
 		return -EINVAL;
 	}

 	chip->irq_type[nr] = type; /* used for enable/disable */

 	gsta_irq_enable(d);
 	return 0;
 }

 static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
 {
 	struct gsta_gpio *chip = dev_id;
 	struct gsta_regs __iomem *regs;
 	u32 is;
 	int i, nr, base;
 	irqreturn_t ret = IRQ_NONE;

 	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
 		regs = chip->regs[i];
 		base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
 		while ((is = readl(&regs->is))) {
 			nr = __ffs(is);
 			irq = base + nr;
 			generic_handle_irq(irq);
 			writel(1 << nr, &regs->ic);
 			ret = IRQ_HANDLED;
 		}
 	}
 	return ret;
 }

 static void gsta_alloc_irq_chip(struct gsta_gpio *chip)
 {
 	struct irq_chip_generic *gc;
 	struct irq_chip_type *ct;

 	gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base,
 				     chip->reg_base, handle_simple_irq);
 	gc->private = chip;
 	ct = gc->chip_types;

 	ct->chip.irq_set_type = gsta_irq_type;
 	ct->chip.irq_disable = gsta_irq_disable;
 	ct->chip.irq_enable = gsta_irq_enable;

 	/* FIXME: this makes at most 32 interrupts. Request 0 by now */
 	irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0,
 			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);

 	/* Set up all all 128 interrupts: code from setup_generic_chip */
 	{
 		struct irq_chip_type *ct = gc->chip_types;
 		int i, j;
 		for (j = 0; j < GSTA_NR_GPIO; j++) {
 			i = chip->irq_base + j;
 			irq_set_chip_and_handler(i, &ct->chip, ct->handler);
 			irq_set_chip_data(i, gc);
 			irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
 		}
 		gc->irq_cnt = i - gc->irq_base;
 	}
 }

 /* The platform device used here is instantiated by the MFD device */
 static int gsta_probe(struct platform_device *dev)
 {
 	int i, err;
 	struct pci_dev *pdev;
 	struct sta2x11_gpio_pdata *gpio_pdata;
 	struct gsta_gpio *chip;
 	struct resource *res;

 	pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev);
 	gpio_pdata = dev_get_platdata(&pdev->dev);

 	if (gpio_pdata == NULL)
 		dev_err(&dev->dev, "no gpio config\n");
 	pr_debug("gpio config: %p\n", gpio_pdata);

 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);

 	chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 	chip->dev = &dev->dev;
 	chip->reg_base = devm_ioremap_resource(&dev->dev, res);
 	if (IS_ERR(chip->reg_base))
 		return PTR_ERR(chip->reg_base);

 	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
 		chip->regs[i] = chip->reg_base + i * 4096;
 		/* disable all irqs */
 		writel(0, &chip->regs[i]->rimsc);
 		writel(0, &chip->regs[i]->fimsc);
 		writel(~0, &chip->regs[i]->ic);
 	}
 	spin_lock_init(&chip->lock);
 	gsta_gpio_setup(chip);
 	if (gpio_pdata)
 		for (i = 0; i < GSTA_NR_GPIO; i++)
 			gsta_set_config(chip, i, gpio_pdata->pinconfig[i]);

 	/* 384 was used in previous code: be compatible for other drivers */
 	err = devm_irq_alloc_descs(&dev->dev, -1, 384,
 				   GSTA_NR_GPIO, NUMA_NO_NODE);
 	if (err < 0) {
 		dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
 			 -err);
 		return err;
 	}
 	chip->irq_base = err;
 	gsta_alloc_irq_chip(chip);

 	err = devm_request_irq(&dev->dev, pdev->irq, gsta_gpio_handler,
 			       IRQF_SHARED, KBUILD_MODNAME, chip);
 	if (err < 0) {
 		dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
 			-err);
 		return err;
 	}

 	err = devm_gpiochip_add_data(&dev->dev, &chip->gpio, chip);
 	if (err < 0) {
 		dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
 			-err);
 		return err;
 	}

 	platform_set_drvdata(dev, chip);
 	return 0;
 }

 static struct platform_driver sta2x11_gpio_platform_driver = {
 	.driver = {
 		.name	= "sta2x11-gpio",
 	},
 	.probe = gsta_probe,
 };
 builtin_platform_driver(sta2x11_gpio_platform_driver);
	/*
	* STMicroelectronics ConneXt (STA2X11) GPIO driver
	*
	* Copyright 2012 ST Microelectronics (Alessandro Rubini)
	* Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
	* Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
	*
	* 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.
	*
	* 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/gpio.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>
	#include <linux/mfd/sta2x11-mfd.h>

	struct gsta_regs {
	u32 dat; /* 0x00 */
	u32 dats;
	u32 datc;
	u32 pdis;
	u32 dir; /* 0x10 */
	u32 dirs;
	u32 dirc;
	u32 unused_1c;
	u32 afsela; /* 0x20 */
	u32 unused_24[7];
	u32 rimsc; /* 0x40 */
	u32 fimsc;
	u32 is;
	u32 ic;
	};

	struct gsta_gpio {
	spinlock_t lock;
	struct device *dev;
	void __iomem *reg_base;
	struct gsta_regs __iomem *regs[GSTA_NR_BLOCKS];
	struct gpio_chip gpio;
	int irq_base;
	/* FIXME: save the whole config here (AF, ...) */
	unsigned irq_type[GSTA_NR_GPIO];
	};

	static inline struct gsta_regs __iomem __regs(struct gsta_gpio chip, int nr)
	{
	return chip->regs[nr / GSTA_GPIO_PER_BLOCK];
	}

	static inline u32 __bit(int nr)
	{
	return 1U << (nr % GSTA_GPIO_PER_BLOCK);
	}

	/*
	* gpio methods
	*/

	static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
	{
	struct gsta_gpio *chip = gpiochip_get_data(gpio);
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);

	if (val)
	writel(bit, &regs->dats);
	else
	writel(bit, &regs->datc);
	}

	static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
	{
	struct gsta_gpio *chip = gpiochip_get_data(gpio);
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);

	return !!(readl(&regs->dat) & bit);
	}

	static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
	int val)
	{
	struct gsta_gpio *chip = gpiochip_get_data(gpio);
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);

	writel(bit, &regs->dirs);
	/* Data register after direction, otherwise pullup/down is selected */
	if (val)
	writel(bit, &regs->dats);
	else
	writel(bit, &regs->datc);
	return 0;
	}

	static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
	{
	struct gsta_gpio *chip = gpiochip_get_data(gpio);
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);

	writel(bit, &regs->dirc);
	return 0;
	}

	static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
	{
	struct gsta_gpio *chip = gpiochip_get_data(gpio);
	return chip->irq_base + offset;
	}

	static void gsta_gpio_setup(struct gsta_gpio chip) / called from probe */
	{
	struct gpio_chip *gpio = &chip->gpio;

	/*
	* ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
	* from the end. However, for compatibility, we need the first
	* ConneXt device to start from gpio 0: it's the main chipset
	* on most boards so documents and drivers assume gpio0..gpio127
	*/
	static int gpio_base;

	gpio->label = dev_name(chip->dev);
	gpio->owner = THIS_MODULE;
	gpio->direction_input = gsta_gpio_direction_input;
	gpio->get = gsta_gpio_get;
	gpio->direction_output = gsta_gpio_direction_output;
	gpio->set = gsta_gpio_set;
	gpio->dbg_show = NULL;
	gpio->base = gpio_base;
	gpio->ngpio = GSTA_NR_GPIO;
	gpio->can_sleep = false;
	gpio->to_irq = gsta_gpio_to_irq;

	/*
	* After the first device, turn to dynamic gpio numbers.
	* For example, with ARCH_NR_GPIOS = 256 we can fit two cards
	*/
	if (!gpio_base)
	gpio_base = -1;
	}

	/*
	* Special method: alternate functions and pullup/pulldown. This is only
	* invoked on startup to configure gpio's according to platform data.
	* FIXME : this functionality shall be managed (and exported to other drivers)
	* via the pin control subsystem.
	*/
	static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
	{
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	unsigned long flags;
	u32 bit = __bit(nr);
	u32 val;
	int err = 0;

	pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg);

	if (cfg == PINMUX_TYPE_NONE)
	return;

	/* Alternate function or not? */
	spin_lock_irqsave(&chip->lock, flags);
	val = readl(&regs->afsela);
	if (cfg == PINMUX_TYPE_FUNCTION)
	val \|= bit;
	else
	val &= ~bit;
	writel(val \| bit, &regs->afsela);
	if (cfg == PINMUX_TYPE_FUNCTION) {
	spin_unlock_irqrestore(&chip->lock, flags);
	return;
	}

	/* not alternate function: set details */
	switch (cfg) {
	case PINMUX_TYPE_OUTPUT_LOW:
	writel(bit, &regs->dirs);
	writel(bit, &regs->datc);
	break;
	case PINMUX_TYPE_OUTPUT_HIGH:
	writel(bit, &regs->dirs);
	writel(bit, &regs->dats);
	break;
	case PINMUX_TYPE_INPUT:
	writel(bit, &regs->dirc);
	val = readl(&regs->pdis) \| bit;
	writel(val, &regs->pdis);
	break;
	case PINMUX_TYPE_INPUT_PULLUP:
	writel(bit, &regs->dirc);
	val = readl(&regs->pdis) & ~bit;
	writel(val, &regs->pdis);
	writel(bit, &regs->dats);
	break;
	case PINMUX_TYPE_INPUT_PULLDOWN:
	writel(bit, &regs->dirc);
	val = readl(&regs->pdis) & ~bit;
	writel(val, &regs->pdis);
	writel(bit, &regs->datc);
	break;
	default:
	err = 1;
	}
	spin_unlock_irqrestore(&chip->lock, flags);
	if (err)
	pr_err("%s: chip %p, pin %i, cfg %i is invalid\n",
	__func__, chip, nr, cfg);
	}

	/*
	* Irq methods
	*/

	static void gsta_irq_disable(struct irq_data *data)
	{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	struct gsta_gpio *chip = gc->private;
	int nr = data->irq - chip->irq_base;
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);
	u32 val;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
	val = readl(&regs->rimsc) & ~bit;
	writel(val, &regs->rimsc);
	}
	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
	val = readl(&regs->fimsc) & ~bit;
	writel(val, &regs->fimsc);
	}
	spin_unlock_irqrestore(&chip->lock, flags);
	return;
	}

	static void gsta_irq_enable(struct irq_data *data)
	{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	struct gsta_gpio *chip = gc->private;
	int nr = data->irq - chip->irq_base;
	struct gsta_regs __iomem *regs = __regs(chip, nr);
	u32 bit = __bit(nr);
	u32 val;
	int type;
	unsigned long flags;

	type = chip->irq_type[nr];

	spin_lock_irqsave(&chip->lock, flags);
	val = readl(&regs->rimsc);
	if (type & IRQ_TYPE_EDGE_RISING)
	writel(val \| bit, &regs->rimsc);
	else
	writel(val & ~bit, &regs->rimsc);
	val = readl(&regs->rimsc);
	if (type & IRQ_TYPE_EDGE_FALLING)
	writel(val \| bit, &regs->fimsc);
	else
	writel(val & ~bit, &regs->fimsc);
	spin_unlock_irqrestore(&chip->lock, flags);
	return;
	}

	static int gsta_irq_type(struct irq_data *d, unsigned int type)
	{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct gsta_gpio *chip = gc->private;
	int nr = d->irq - chip->irq_base;

	/* We only support edge interrupts */
	if (!(type & (IRQ_TYPE_EDGE_RISING \| IRQ_TYPE_EDGE_FALLING))) {
	pr_debug("%s: unsupported type 0x%x\n", __func__, type);
	return -EINVAL;
	}

	chip->irq_type[nr] = type; /* used for enable/disable */

	gsta_irq_enable(d);
	return 0;
	}

	static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
	{
	struct gsta_gpio *chip = dev_id;
	struct gsta_regs __iomem *regs;
	u32 is;
	int i, nr, base;
	irqreturn_t ret = IRQ_NONE;

	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
	regs = chip->regs[i];
	base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
	while ((is = readl(&regs->is))) {
	nr = __ffs(is);
	irq = base + nr;
	generic_handle_irq(irq);
	writel(1 << nr, &regs->ic);
	ret = IRQ_HANDLED;
	}
	}
	return ret;
	}

	static void gsta_alloc_irq_chip(struct gsta_gpio *chip)
	{
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;

	gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base,
	chip->reg_base, handle_simple_irq);
	gc->private = chip;
	ct = gc->chip_types;

	ct->chip.irq_set_type = gsta_irq_type;
	ct->chip.irq_disable = gsta_irq_disable;
	ct->chip.irq_enable = gsta_irq_enable;

	/* FIXME: this makes at most 32 interrupts. Request 0 by now */
	irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0,
	IRQ_NOREQUEST \| IRQ_NOPROBE, 0);

	/* Set up all all 128 interrupts: code from setup_generic_chip */
	{
	struct irq_chip_type *ct = gc->chip_types;
	int i, j;
	for (j = 0; j < GSTA_NR_GPIO; j++) {
	i = chip->irq_base + j;
	irq_set_chip_and_handler(i, &ct->chip, ct->handler);
	irq_set_chip_data(i, gc);
	irq_clear_status_flags(i, IRQ_NOREQUEST \| IRQ_NOPROBE);
	}
	gc->irq_cnt = i - gc->irq_base;
	}
	}

	/* The platform device used here is instantiated by the MFD device */
	static int gsta_probe(struct platform_device *dev)
	{
	int i, err;
	struct pci_dev *pdev;
	struct sta2x11_gpio_pdata *gpio_pdata;
	struct gsta_gpio *chip;
	struct resource *res;

	pdev = (struct pci_dev *)dev_get_platdata(&dev->dev);
	gpio_pdata = dev_get_platdata(&pdev->dev);

	if (gpio_pdata == NULL)
	dev_err(&dev->dev, "no gpio config\n");
	pr_debug("gpio config: %p\n", gpio_pdata);

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);

	chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL);
	if (!chip)
	return -ENOMEM;
	chip->dev = &dev->dev;
	chip->reg_base = devm_ioremap_resource(&dev->dev, res);
	if (IS_ERR(chip->reg_base))
	return PTR_ERR(chip->reg_base);

	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
	chip->regs[i] = chip->reg_base + i * 4096;
	/* disable all irqs */
	writel(0, &chip->regs[i]->rimsc);
	writel(0, &chip->regs[i]->fimsc);
	writel(~0, &chip->regs[i]->ic);
	}
	spin_lock_init(&chip->lock);
	gsta_gpio_setup(chip);
	if (gpio_pdata)
	for (i = 0; i < GSTA_NR_GPIO; i++)
	gsta_set_config(chip, i, gpio_pdata->pinconfig[i]);

	/* 384 was used in previous code: be compatible for other drivers */
	err = devm_irq_alloc_descs(&dev->dev, -1, 384,
	GSTA_NR_GPIO, NUMA_NO_NODE);
	if (err < 0) {
	dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
	-err);
	return err;
	}
	chip->irq_base = err;
	gsta_alloc_irq_chip(chip);

	err = devm_request_irq(&dev->dev, pdev->irq, gsta_gpio_handler,
	IRQF_SHARED, KBUILD_MODNAME, chip);
	if (err < 0) {
	dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
	-err);
	return err;
	}

	err = devm_gpiochip_add_data(&dev->dev, &chip->gpio, chip);
	if (err < 0) {
	dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
	-err);
	return err;
	}

	platform_set_drvdata(dev, chip);
	return 0;
	}

	static struct platform_driver sta2x11_gpio_platform_driver = {
	.driver = {
	.name = "sta2x11-gpio",
	},
	.probe = gsta_probe,
	};
	builtin_platform_driver(sta2x11_gpio_platform_driver);