Contributors: 8
Author Tokens Token Proportion Commits Commit Proportion
Linus Walleij 3332 99.11% 22 70.97%
Thomas Gleixner 11 0.33% 2 6.45%
Thierry Reding 10 0.30% 2 6.45%
Jiang Liu 4 0.12% 1 3.23%
Jonas Gorski 2 0.06% 1 3.23%
Gustavo A. R. Silva 1 0.03% 1 3.23%
Arnd Bergmann 1 0.03% 1 3.23%
Axel Lin 1 0.03% 1 3.23%
Total 3362 31 


// SPDX-License-Identifier: GPL-2.0-only
/*
 * U300 GPIO module.
 *
 * Copyright (C) 2007-2012 ST-Ericsson AB
 * COH 901 571/3 - Used in DB3210 (U365 2.0) and DB3350 (U335 1.0)
 * Author: Linus Walleij <linus.walleij@linaro.org>
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
 */
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/pinconf-generic.h>
#include "pinctrl-coh901.h"

#define U300_GPIO_PORT_STRIDE				(0x30)
/*
 * Control Register 32bit (R/W)
 * bit 15-9 (mask 0x0000FE00) contains the number of cores. 8*cores
 * gives the number of GPIO pins.
 * bit 8-2  (mask 0x000001FC) contains the core version ID.
 */
#define U300_GPIO_CR					(0x00)
#define U300_GPIO_CR_SYNC_SEL_ENABLE			(0x00000002UL)
#define U300_GPIO_CR_BLOCK_CLKRQ_ENABLE			(0x00000001UL)
#define U300_GPIO_PXPDIR				(0x04)
#define U300_GPIO_PXPDOR				(0x08)
#define U300_GPIO_PXPCR					(0x0C)
#define U300_GPIO_PXPCR_ALL_PINS_MODE_MASK		(0x0000FFFFUL)
#define U300_GPIO_PXPCR_PIN_MODE_MASK			(0x00000003UL)
#define U300_GPIO_PXPCR_PIN_MODE_SHIFT			(0x00000002UL)
#define U300_GPIO_PXPCR_PIN_MODE_INPUT			(0x00000000UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL	(0x00000001UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN	(0x00000002UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE	(0x00000003UL)
#define U300_GPIO_PXPER					(0x10)
#define U300_GPIO_PXPER_ALL_PULL_UP_DISABLE_MASK	(0x000000FFUL)
#define U300_GPIO_PXPER_PULL_UP_DISABLE			(0x00000001UL)
#define U300_GPIO_PXIEV					(0x14)
#define U300_GPIO_PXIEN					(0x18)
#define U300_GPIO_PXIFR					(0x1C)
#define U300_GPIO_PXICR					(0x20)
#define U300_GPIO_PXICR_ALL_IRQ_CONFIG_MASK		(0x000000FFUL)
#define U300_GPIO_PXICR_IRQ_CONFIG_MASK			(0x00000001UL)
#define U300_GPIO_PXICR_IRQ_CONFIG_FALLING_EDGE		(0x00000000UL)
#define U300_GPIO_PXICR_IRQ_CONFIG_RISING_EDGE		(0x00000001UL)

/* 8 bits per port, no version has more than 7 ports */
#define U300_GPIO_NUM_PORTS 7
#define U300_GPIO_PINS_PER_PORT 8
#define U300_GPIO_MAX (U300_GPIO_PINS_PER_PORT * U300_GPIO_NUM_PORTS)

struct u300_gpio_port {
	struct u300_gpio *gpio;
	char name[8];
	int irq;
	int number;
	u8 toggle_edge_mode;
};

struct u300_gpio {
	struct gpio_chip chip;
	struct u300_gpio_port ports[U300_GPIO_NUM_PORTS];
	struct clk *clk;
	void __iomem *base;
	struct device *dev;
	u32 stride;
	/* Register offsets */
	u32 pcr;
	u32 dor;
	u32 dir;
	u32 per;
	u32 icr;
	u32 ien;
	u32 iev;
};

/*
 * Macro to expand to read a specific register found in the "gpio"
 * struct. It requires the struct u300_gpio *gpio variable to exist in
 * its context. It calculates the port offset from the given pin
 * offset, muliplies by the port stride and adds the register offset
 * so it provides a pointer to the desired register.
 */
#define U300_PIN_REG(pin, reg) \
	(gpio->base + (pin >> 3) * gpio->stride + gpio->reg)

/*
 * Provides a bitmask for a specific gpio pin inside an 8-bit GPIO
 * register.
 */
#define U300_PIN_BIT(pin) \
	(1 << (pin & 0x07))

struct u300_gpio_confdata {
	u16 bias_mode;
	bool output;
	int outval;
};

#define U300_FLOATING_INPUT { \
	.bias_mode = PIN_CONFIG_BIAS_HIGH_IMPEDANCE, \
	.output = false, \
}

#define U300_PULL_UP_INPUT { \
	.bias_mode = PIN_CONFIG_BIAS_PULL_UP, \
	.output = false, \
}

#define U300_OUTPUT_LOW { \
	.output = true, \
	.outval = 0, \
}

#define U300_OUTPUT_HIGH { \
	.output = true, \
	.outval = 1, \
}

/* Initial configuration */
static const struct u300_gpio_confdata __initconst
bs335_gpio_config[U300_GPIO_NUM_PORTS][U300_GPIO_PINS_PER_PORT] = {
	/* Port 0, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_OUTPUT_HIGH,
		U300_FLOATING_INPUT,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
	},
	/* Port 1, pins 0-7 */
	{
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
		U300_FLOATING_INPUT,
		U300_OUTPUT_HIGH,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
	},
	/* Port 2, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
	},
	/* Port 3, pins 0-7 */
	{
		U300_PULL_UP_INPUT,
		U300_OUTPUT_LOW,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 4, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 5, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 6, pind 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	}
};

static int u300_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);

	return !!(readl(U300_PIN_REG(offset, dir)) & U300_PIN_BIT(offset));
}

static void u300_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);

	val = readl(U300_PIN_REG(offset, dor));
	if (value)
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, dor));
	else
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, dor));

	local_irq_restore(flags);
}

static int u300_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, pcr));
	/* Mask out this pin, note 2 bits per setting */
	val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK << ((offset & 0x07) << 1));
	writel(val, U300_PIN_REG(offset, pcr));
	local_irq_restore(flags);
	return 0;
}

static int u300_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
				      int value)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	unsigned long flags;
	u32 oldmode;
	u32 val;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, pcr));
	/*
	 * Drive mode must be set by the special mode set function, set
	 * push/pull mode by default if no mode has been selected.
	 */
	oldmode = val & (U300_GPIO_PXPCR_PIN_MODE_MASK <<
			 ((offset & 0x07) << 1));
	/* mode = 0 means input, else some mode is already set */
	if (oldmode == 0) {
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK <<
			 ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
	}
	u300_gpio_set(chip, offset, value);
	local_irq_restore(flags);
	return 0;
}

/* Returning -EINVAL means "supported but not available" */
int u300_gpio_config_get(struct gpio_chip *chip,
			 unsigned offset,
			 unsigned long *config)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	enum pin_config_param param = (enum pin_config_param) *config;
	bool biasmode;
	u32 drmode;

	/* One bit per pin, clamp to bool range */
	biasmode = !!(readl(U300_PIN_REG(offset, per)) & U300_PIN_BIT(offset));

	/* Mask out the two bits for this pin and shift to bits 0,1 */
	drmode = readl(U300_PIN_REG(offset, pcr));
	drmode &= (U300_GPIO_PXPCR_PIN_MODE_MASK << ((offset & 0x07) << 1));
	drmode >>= ((offset & 0x07) << 1);

	switch (param) {
	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
		*config = 0;
		if (biasmode)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		*config = 0;
		if (!biasmode)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE)
			return 0;
		else
			return -EINVAL;
		break;
	default:
		break;
	}
	return -ENOTSUPP;
}

int u300_gpio_config_set(struct gpio_chip *chip, unsigned offset,
			 enum pin_config_param param)
{
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);
	switch (param) {
	case PIN_CONFIG_BIAS_DISABLE:
	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
		val = readl(U300_PIN_REG(offset, per));
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		val = readl(U300_PIN_REG(offset, per));
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	default:
		local_irq_restore(flags);
		dev_err(gpio->dev, "illegal configuration requested\n");
		return -EINVAL;
	}
	local_irq_restore(flags);
	return 0;
}

static const struct gpio_chip u300_gpio_chip = {
	.label			= "u300-gpio-chip",
	.owner			= THIS_MODULE,
	.request		= gpiochip_generic_request,
	.free			= gpiochip_generic_free,
	.get			= u300_gpio_get,
	.set			= u300_gpio_set,
	.direction_input	= u300_gpio_direction_input,
	.direction_output	= u300_gpio_direction_output,
};

static void u300_toggle_trigger(struct u300_gpio *gpio, unsigned offset)
{
	u32 val;

	val = readl(U300_PIN_REG(offset, icr));
	/* Set mode depending on state */
	if (u300_gpio_get(&gpio->chip, offset)) {
		/* High now, let's trigger on falling edge next then */
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		dev_dbg(gpio->dev, "next IRQ on falling edge on pin %d\n",
			offset);
	} else {
		/* Low now, let's trigger on rising edge next then */
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		dev_dbg(gpio->dev, "next IRQ on rising edge on pin %d\n",
			offset);
	}
}

static int u300_gpio_irq_type(struct irq_data *d, unsigned trigger)
{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	struct u300_gpio_port *port = &gpio->ports[d->hwirq >> 3];
	int offset = d->hwirq;
	u32 val;

	if ((trigger & IRQF_TRIGGER_RISING) &&
	    (trigger & IRQF_TRIGGER_FALLING)) {
		/*
		 * The GPIO block can only trigger on falling OR rising edges,
		 * not both. So we need to toggle the mode whenever the pin
		 * goes from one state to the other with a special state flag
		 */
		dev_dbg(gpio->dev,
			"trigger on both rising and falling edge on pin %d\n",
			offset);
		port->toggle_edge_mode |= U300_PIN_BIT(offset);
		u300_toggle_trigger(gpio, offset);
	} else if (trigger & IRQF_TRIGGER_RISING) {
		dev_dbg(gpio->dev, "trigger on rising edge on pin %d\n",
			offset);
		val = readl(U300_PIN_REG(offset, icr));
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		port->toggle_edge_mode &= ~U300_PIN_BIT(offset);
	} else if (trigger & IRQF_TRIGGER_FALLING) {
		dev_dbg(gpio->dev, "trigger on falling edge on pin %d\n",
			offset);
		val = readl(U300_PIN_REG(offset, icr));
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		port->toggle_edge_mode &= ~U300_PIN_BIT(offset);
	}

	return 0;
}

static void u300_gpio_irq_enable(struct irq_data *d)
{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	struct u300_gpio_port *port = &gpio->ports[d->hwirq >> 3];
	int offset = d->hwirq;
	u32 val;
	unsigned long flags;

	dev_dbg(gpio->dev, "enable IRQ for hwirq %lu on port %s, offset %d\n",
		 d->hwirq, port->name, offset);
	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, ien));
	writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, ien));
	local_irq_restore(flags);
}

static void u300_gpio_irq_disable(struct irq_data *d)
{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	int offset = d->hwirq;
	u32 val;
	unsigned long flags;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, ien));
	writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, ien));
	local_irq_restore(flags);
}

static struct irq_chip u300_gpio_irqchip = {
	.name			= "u300-gpio-irqchip",
	.irq_enable		= u300_gpio_irq_enable,
	.irq_disable		= u300_gpio_irq_disable,
	.irq_set_type		= u300_gpio_irq_type,
};

static void u300_gpio_irq_handler(struct irq_desc *desc)
{
	unsigned int irq = irq_desc_get_irq(desc);
	struct irq_chip *parent_chip = irq_desc_get_chip(desc);
	struct gpio_chip *chip = irq_desc_get_handler_data(desc);
	struct u300_gpio *gpio = gpiochip_get_data(chip);
	struct u300_gpio_port *port = &gpio->ports[irq - chip->base];
	int pinoffset = port->number << 3; /* get the right stride */
	unsigned long val;

	chained_irq_enter(parent_chip, desc);

	/* Read event register */
	val = readl(U300_PIN_REG(pinoffset, iev));
	/* Mask relevant bits */
	val &= 0xFFU; /* 8 bits per port */
	/* ACK IRQ (clear event) */
	writel(val, U300_PIN_REG(pinoffset, iev));

	/* Call IRQ handler */
	if (val != 0) {
		int irqoffset;

		for_each_set_bit(irqoffset, &val, U300_GPIO_PINS_PER_PORT) {
			int offset = pinoffset + irqoffset;
			int pin_irq = irq_find_mapping(chip->irq.domain, offset);

			dev_dbg(gpio->dev, "GPIO IRQ %d on pin %d\n",
				pin_irq, offset);
			generic_handle_irq(pin_irq);
			/*
			 * Triggering IRQ on both rising and falling edge
			 * needs mockery
			 */
			if (port->toggle_edge_mode & U300_PIN_BIT(offset))
				u300_toggle_trigger(gpio, offset);
		}
	}

	chained_irq_exit(parent_chip, desc);
}

static void __init u300_gpio_init_pin(struct u300_gpio *gpio,
				      int offset,
				      const struct u300_gpio_confdata *conf)
{
	/* Set mode: input or output */
	if (conf->output) {
		u300_gpio_direction_output(&gpio->chip, offset, conf->outval);

		/* Deactivate bias mode for output */
		u300_gpio_config_set(&gpio->chip, offset,
				     PIN_CONFIG_BIAS_HIGH_IMPEDANCE);

		/* Set drive mode for output */
		u300_gpio_config_set(&gpio->chip, offset,
				     PIN_CONFIG_DRIVE_PUSH_PULL);

		dev_dbg(gpio->dev, "set up pin %d as output, value: %d\n",
			offset, conf->outval);
	} else {
		u300_gpio_direction_input(&gpio->chip, offset);

		/* Always set output low on input pins */
		u300_gpio_set(&gpio->chip, offset, 0);

		/* Set bias mode for input */
		u300_gpio_config_set(&gpio->chip, offset, conf->bias_mode);

		dev_dbg(gpio->dev, "set up pin %d as input, bias: %04x\n",
			offset, conf->bias_mode);
	}
}

static void __init u300_gpio_init_coh901571(struct u300_gpio *gpio)
{
	int i, j;

	/* Write default config and values to all pins */
	for (i = 0; i < U300_GPIO_NUM_PORTS; i++) {
		for (j = 0; j < 8; j++) {
			const struct u300_gpio_confdata *conf;
			int offset = (i*8) + j;

			conf = &bs335_gpio_config[i][j];
			u300_gpio_init_pin(gpio, offset, conf);
		}
	}
}

/*
 * Here we map a GPIO in the local gpio_chip pin space to a pin in
 * the local pinctrl pin space. The pin controller used is
 * pinctrl-u300.
 */
struct coh901_pinpair {
	unsigned int offset;
	unsigned int pin_base;
};

#define COH901_PINRANGE(a, b) { .offset = a, .pin_base = b }

static struct coh901_pinpair coh901_pintable[] = {
	COH901_PINRANGE(10, 426),
	COH901_PINRANGE(11, 180),
	COH901_PINRANGE(12, 165), /* MS/MMC card insertion */
	COH901_PINRANGE(13, 179),
	COH901_PINRANGE(14, 178),
	COH901_PINRANGE(16, 194),
	COH901_PINRANGE(17, 193),
	COH901_PINRANGE(18, 192),
	COH901_PINRANGE(19, 191),
	COH901_PINRANGE(20, 186),
	COH901_PINRANGE(21, 185),
	COH901_PINRANGE(22, 184),
	COH901_PINRANGE(23, 183),
	COH901_PINRANGE(24, 182),
	COH901_PINRANGE(25, 181),
};

static int __init u300_gpio_probe(struct platform_device *pdev)
{
	struct u300_gpio *gpio;
	struct resource *memres;
	int err = 0;
	int portno;
	u32 val;
	u32 ifr;
	int i;

	gpio = devm_kzalloc(&pdev->dev, sizeof(struct u300_gpio), GFP_KERNEL);
	if (gpio == NULL)
		return -ENOMEM;

	gpio->chip = u300_gpio_chip;
	gpio->chip.ngpio = U300_GPIO_NUM_PORTS * U300_GPIO_PINS_PER_PORT;
	gpio->chip.parent = &pdev->dev;
	gpio->chip.base = 0;
	gpio->dev = &pdev->dev;

	memres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gpio->base = devm_ioremap_resource(&pdev->dev, memres);
	if (IS_ERR(gpio->base))
		return PTR_ERR(gpio->base);

	gpio->clk = devm_clk_get(gpio->dev, NULL);
	if (IS_ERR(gpio->clk)) {
		err = PTR_ERR(gpio->clk);
		dev_err(gpio->dev, "could not get GPIO clock\n");
		return err;
	}

	err = clk_prepare_enable(gpio->clk);
	if (err) {
		dev_err(gpio->dev, "could not enable GPIO clock\n");
		return err;
	}

	dev_info(gpio->dev,
		 "initializing GPIO Controller COH 901 571/3\n");
	gpio->stride = U300_GPIO_PORT_STRIDE;
	gpio->pcr = U300_GPIO_PXPCR;
	gpio->dor = U300_GPIO_PXPDOR;
	gpio->dir = U300_GPIO_PXPDIR;
	gpio->per = U300_GPIO_PXPER;
	gpio->icr = U300_GPIO_PXICR;
	gpio->ien = U300_GPIO_PXIEN;
	gpio->iev = U300_GPIO_PXIEV;
	ifr = U300_GPIO_PXIFR;

	val = readl(gpio->base + U300_GPIO_CR);
	dev_info(gpio->dev, "COH901571/3 block version: %d, " \
		 "number of cores: %d totalling %d pins\n",
		 ((val & 0x000001FC) >> 2),
		 ((val & 0x0000FE00) >> 9),
		 ((val & 0x0000FE00) >> 9) * 8);
	writel(U300_GPIO_CR_BLOCK_CLKRQ_ENABLE,
	       gpio->base + U300_GPIO_CR);
	u300_gpio_init_coh901571(gpio);

#ifdef CONFIG_OF_GPIO
	gpio->chip.of_node = pdev->dev.of_node;
#endif
	err = gpiochip_add_data(&gpio->chip, gpio);
	if (err) {
		dev_err(gpio->dev, "unable to add gpiochip: %d\n", err);
		goto err_no_chip;
	}

	err = gpiochip_irqchip_add(&gpio->chip,
				   &u300_gpio_irqchip,
				   0,
				   handle_simple_irq,
				   IRQ_TYPE_EDGE_FALLING);
	if (err) {
		dev_err(gpio->dev, "no GPIO irqchip\n");
		goto err_no_irqchip;
	}

	/* Add each port with its IRQ separately */
	for (portno = 0 ; portno < U300_GPIO_NUM_PORTS; portno++) {
		struct u300_gpio_port *port = &gpio->ports[portno];

		snprintf(port->name, 8, "gpio%d", portno);
		port->number = portno;
		port->gpio = gpio;

		port->irq = platform_get_irq(pdev, portno);

		gpiochip_set_chained_irqchip(&gpio->chip,
					     &u300_gpio_irqchip,
					     port->irq,
					     u300_gpio_irq_handler);

		/* Turns off irq force (test register) for this port */
		writel(0x0, gpio->base + portno * gpio->stride + ifr);
	}
	dev_dbg(gpio->dev, "initialized %d GPIO ports\n", portno);

	/*
	 * Add pinctrl pin ranges, the pin controller must be registered
	 * at this point
	 */
	for (i = 0; i < ARRAY_SIZE(coh901_pintable); i++) {
		struct coh901_pinpair *p = &coh901_pintable[i];

		err = gpiochip_add_pin_range(&gpio->chip, "pinctrl-u300",
					     p->offset, p->pin_base, 1);
		if (err)
			goto err_no_range;
	}

	platform_set_drvdata(pdev, gpio);

	return 0;

err_no_range:
err_no_irqchip:
	gpiochip_remove(&gpio->chip);
err_no_chip:
	clk_disable_unprepare(gpio->clk);
	dev_err(&pdev->dev, "module ERROR:%d\n", err);
	return err;
}

static int __exit u300_gpio_remove(struct platform_device *pdev)
{
	struct u300_gpio *gpio = platform_get_drvdata(pdev);

	/* Turn off the GPIO block */
	writel(0x00000000U, gpio->base + U300_GPIO_CR);

	gpiochip_remove(&gpio->chip);
	clk_disable_unprepare(gpio->clk);
	return 0;
}

static const struct of_device_id u300_gpio_match[] = {
	{ .compatible = "stericsson,gpio-coh901" },
	{},
};

static struct platform_driver u300_gpio_driver = {
	.driver		= {
		.name	= "u300-gpio",
		.of_match_table = u300_gpio_match,
	},
	.remove		= __exit_p(u300_gpio_remove),
};

static int __init u300_gpio_init(void)
{
	return platform_driver_probe(&u300_gpio_driver, u300_gpio_probe);
}

static void __exit u300_gpio_exit(void)
{
	platform_driver_unregister(&u300_gpio_driver);
}

arch_initcall(u300_gpio_init);
module_exit(u300_gpio_exit);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("ST-Ericsson AB COH 901 335/COH 901 571/3 GPIO driver");
MODULE_LICENSE("GPL");