pinctrl: move the U300 GPIO driver to pinctrl

This driver will be converted to a dual GPIO + pinctrl driver
since it supports biasing and driving control options. Hopefully
it can serve as an example.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 927 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index e17e2f8001d2..e087f0219f48 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -30,6 +30,15 @@ config PINMUX_U300
 	depends on ARCH_U300
 	select PINMUX
 
+config PINCTRL_COH901
+	bool "ST-Ericsson U300 COH 901 335/571 GPIO"
+	depends on GPIOLIB && ARCH_U300
+	help
+	  Say yes here to support GPIO interface on ST-Ericsson U300.
+	  The names of the two IP block variants supported are
+	  COH 901 335 and COH 901 571/3. They contain 3, 5 or 7
+	  ports of 8 GPIO pins each.
+
 endmenu
 
 endif
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 50a2e2f6bc27..5f3e4d65465a 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_PINCTRL)		+= core.o
 obj-$(CONFIG_PINMUX)		+= pinmux.o
 obj-$(CONFIG_PINMUX_SIRF)	+= pinmux-sirf.o
 obj-$(CONFIG_PINMUX_U300)	+= pinmux-u300.o
+obj-$(CONFIG_PINCTRL_COH901)	+= pinctrl-coh901.o
diff --git a/drivers/pinctrl/pinctrl-coh901.c b/drivers/pinctrl/pinctrl-coh901.c
new file mode 100644
index 000000000000..4035778852b0
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-coh901.c
@@ -0,0 +1,917 @@
+/*
+ * U300 GPIO module.
+ *
+ * Copyright (C) 2007-2011 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * This can driver either of the two basic GPIO cores
+ * available in the U300 platforms:
+ * COH 901 335   - Used in DB3150 (U300 1.0) and DB3200 (U330 1.0)
+ * 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/irq.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.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <mach/gpio-u300.h>
+
+/*
+ * Bias modes for U300 GPIOs
+ *
+ * GPIO_U300_CONFIG_BIAS_UNKNOWN: this bias mode is not known to us
+ * GPIO_U300_CONFIG_BIAS_FLOAT: no specific bias, the GPIO will float or state
+ *	is not controlled by software
+ * GPIO_U300_CONFIG_BIAS_PULL_UP: the GPIO will be pulled up (usually with high
+ *	impedance to VDD)
+ */
+#define GPIO_U300_CONFIG_BIAS_UNKNOWN	0x1000
+#define GPIO_U300_CONFIG_BIAS_FLOAT	0x1001
+#define GPIO_U300_CONFIG_BIAS_PULL_UP	0x1002
+
+/*
+ * Drive modes for U300 GPIOs (output)
+ *
+ * GPIO_U300_CONFIG_DRIVE_PUSH_PULL: the GPIO will be driven actively high and
+ *	low, this is the most typical case and is typically achieved with two
+ *	active transistors on the output
+ * GPIO_U300_CONFIG_DRIVE_OPEN_DRAIN: the GPIO will be driven with open drain
+ *	(open collector) which means it is usually wired with other output
+ *	ports which are then pulled up with an external resistor
+ * GPIO_U300_CONFIG_DRIVE_OPEN_SOURCE: the GPIO will be driven with open drain
+ *	(open emitter) which is the same as open drain mutatis mutandis but
+ *	pulled to ground
+ */
+#define GPIO_U300_CONFIG_DRIVE_PUSH_PULL	0x2000
+#define GPIO_U300_CONFIG_DRIVE_OPEN_DRAIN	0x2001
+#define GPIO_U300_CONFIG_DRIVE_OPEN_SOURCE	0x2002
+
+/*
+ * Register definitions for COH 901 335 variant
+ */
+#define U300_335_PORT_STRIDE				(0x1C)
+/* Port X Pin Data Register 32bit, this is both input and output (R/W) */
+#define U300_335_PXPDIR					(0x00)
+#define U300_335_PXPDOR					(0x00)
+/* Port X Pin Config Register 32bit (R/W) */
+#define U300_335_PXPCR					(0x04)
+/* This register layout is the same in both blocks */
+#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)
+/* Port X Interrupt Event Register 32bit (R/W) */
+#define U300_335_PXIEV					(0x08)
+/* Port X Interrupt Enable Register 32bit (R/W) */
+#define U300_335_PXIEN					(0x0C)
+/* Port X Interrupt Force Register 32bit (R/W) */
+#define U300_335_PXIFR					(0x10)
+/* Port X Interrupt Config Register 32bit (R/W) */
+#define U300_335_PXICR					(0x14)
+/* This register layout is the same in both blocks */
+#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)
+/* Port X Pull-up Enable Register 32bit (R/W) */
+#define U300_335_PXPER					(0x18)
+/* This register layout is the same in both blocks */
+#define U300_GPIO_PXPER_ALL_PULL_UP_DISABLE_MASK	(0x000000FFUL)
+#define U300_GPIO_PXPER_PULL_UP_DISABLE			(0x00000001UL)
+/* Control Register 32bit (R/W) */
+#define U300_335_CR					(0x54)
+#define U300_335_CR_BLOCK_CLOCK_ENABLE			(0x00000001UL)
+
+/*
+ * Register definitions for COH 901 571 / 3 variant
+ */
+#define U300_571_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_571_CR					(0x00)
+#define U300_571_CR_SYNC_SEL_ENABLE			(0x00000002UL)
+#define U300_571_CR_BLOCK_CLKRQ_ENABLE			(0x00000001UL)
+/*
+ * These registers have the same layout and function as the corresponding
+ * COH 901 335 registers, just at different offset.
+ */
+#define U300_571_PXPDIR					(0x04)
+#define U300_571_PXPDOR					(0x08)
+#define U300_571_PXPCR					(0x0C)
+#define U300_571_PXPER					(0x10)
+#define U300_571_PXIEV					(0x14)
+#define U300_571_PXIEN					(0x18)
+#define U300_571_PXIFR					(0x1C)
+#define U300_571_PXICR					(0x20)
+
+/* 8 bits per port, no version has more than 7 ports */
+#define U300_GPIO_PINS_PER_PORT 8
+#define U300_GPIO_MAX (U300_GPIO_PINS_PER_PORT * 7)
+
+struct u300_gpio {
+	struct gpio_chip chip;
+	struct list_head port_list;
+	struct clk *clk;
+	struct resource *memres;
+	void __iomem *base;
+	struct device *dev;
+	int irq_base;
+	u32 stride;
+	/* Register offsets */
+	u32 pcr;
+	u32 dor;
+	u32 dir;
+	u32 per;
+	u32 icr;
+	u32 ien;
+	u32 iev;
+};
+
+struct u300_gpio_port {
+	struct list_head node;
+	struct u300_gpio *gpio;
+	char name[8];
+	int irq;
+	int number;
+	u8 toggle_edge_mode;
+};
+
+/*
+ * 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;
+};
+
+/* BS335 has seven ports of 8 bits each = GPIO pins 0..55 */
+#define BS335_GPIO_NUM_PORTS 7
+/* BS365 has five ports of 8 bits each = GPIO pins 0..39 */
+#define BS365_GPIO_NUM_PORTS 5
+
+#define U300_FLOATING_INPUT { \
+	.bias_mode = GPIO_U300_CONFIG_BIAS_FLOAT, \
+	.output = false, \
+}
+
+#define U300_PULL_UP_INPUT { \
+	.bias_mode = GPIO_U300_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 __initdata u300_gpio_confdata
+bs335_gpio_config[BS335_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 const struct __initdata u300_gpio_confdata
+bs365_gpio_config[BS365_GPIO_NUM_PORTS][U300_GPIO_PINS_PER_PORT] = {
+	/* Port 0, pins 0-7 */
+	{
+		U300_FLOATING_INPUT,
+		U300_OUTPUT_LOW,
+		U300_FLOATING_INPUT,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+		U300_PULL_UP_INPUT,
+		U300_FLOATING_INPUT,
+	},
+	/* Port 1, pins 0-7 */
+	{
+		U300_OUTPUT_LOW,
+		U300_FLOATING_INPUT,
+		U300_OUTPUT_LOW,
+		U300_FLOATING_INPUT,
+		U300_FLOATING_INPUT,
+		U300_OUTPUT_HIGH,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+	},
+	/* Port 2, pins 0-7 */
+	{
+		U300_FLOATING_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+	},
+	/* Port 3, pins 0-7 */
+	{
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+	},
+	/* Port 4, pins 0-7 */
+	{
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		U300_PULL_UP_INPUT,
+		/* These 4 pins doesn't exist on DB3210 */
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+		U300_OUTPUT_LOW,
+	}
+};
+
+/**
+ * to_u300_gpio() - get the pointer to u300_gpio
+ * @chip: the gpio chip member of the structure u300_gpio
+ */
+static inline struct u300_gpio *to_u300_gpio(struct gpio_chip *chip)
+{
+	return container_of(chip, struct u300_gpio, chip);
+}
+
+static int u300_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct u300_gpio *gpio = to_u300_gpio(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 = to_u300_gpio(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 = to_u300_gpio(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 = to_u300_gpio(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;
+}
+
+static int u300_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct u300_gpio *gpio = to_u300_gpio(chip);
+	int retirq = gpio->irq_base + offset;
+
+	dev_dbg(gpio->dev, "request IRQ for GPIO %d, return %d\n", offset,
+		retirq);
+	return retirq;
+}
+
+static int u300_gpio_config(struct gpio_chip *chip, unsigned offset,
+		     u16 param, unsigned long *data)
+{
+	struct u300_gpio *gpio = to_u300_gpio(chip);
+	unsigned long flags;
+	u32 val;
+
+	local_irq_save(flags);
+	switch (param) {
+	case GPIO_U300_CONFIG_BIAS_UNKNOWN:
+	case GPIO_U300_CONFIG_BIAS_FLOAT:
+		val = readl(U300_PIN_REG(offset, per));
+		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
+		break;
+	case GPIO_U300_CONFIG_BIAS_PULL_UP:
+		val = readl(U300_PIN_REG(offset, per));
+		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
+		break;
+	case GPIO_U300_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 GPIO_U300_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 GPIO_U300_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 struct gpio_chip u300_gpio_chip = {
+	.label			= "u300-gpio-chip",
+	.owner			= THIS_MODULE,
+	.get			= u300_gpio_get,
+	.set			= u300_gpio_set,
+	.direction_input	= u300_gpio_direction_input,
+	.direction_output	= u300_gpio_direction_output,
+	.to_irq			= u300_gpio_to_irq,
+};
+
+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 u300_gpio_port *port = irq_data_get_irq_chip_data(d);
+	struct u300_gpio *gpio = port->gpio;
+	int offset = d->irq - gpio->irq_base;
+	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 u300_gpio_port *port = irq_data_get_irq_chip_data(d);
+	struct u300_gpio *gpio = port->gpio;
+	int offset = d->irq - gpio->irq_base;
+	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 void u300_gpio_irq_disable(struct irq_data *d)
+{
+	struct u300_gpio_port *port = irq_data_get_irq_chip_data(d);
+	struct u300_gpio *gpio = port->gpio;
+	int offset = d->irq - gpio->irq_base;
+	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(unsigned irq, struct irq_desc *desc)
+{
+	struct u300_gpio_port *port = irq_get_handler_data(irq);
+	struct u300_gpio *gpio = port->gpio;
+	int pinoffset = port->number << 3; /* get the right stride */
+	unsigned long val;
+
+	desc->irq_data.chip->irq_ack(&desc->irq_data);
+	/* 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 pin_irq = gpio->irq_base + (port->number << 3)
+				+ irqoffset;
+			int offset = pinoffset + irqoffset;
+
+			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);
+		}
+	}
+
+	desc->irq_data.chip->irq_unmask(&desc->irq_data);
+}
+
+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(&gpio->chip, offset,
+				 GPIO_U300_CONFIG_BIAS_FLOAT,
+				 NULL);
+
+		/* Set drive mode for output */
+		u300_gpio_config(&gpio->chip, offset,
+				 GPIO_U300_CONFIG_DRIVE_PUSH_PULL, NULL);
+
+		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(&gpio->chip, offset, conf->bias_mode, NULL);
+
+		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,
+				     struct u300_gpio_platform *plat)
+{
+	int i, j;
+
+	/* Write default config and values to all pins */
+	for (i = 0; i < plat->ports; i++) {
+		for (j = 0; j < 8; j++) {
+			const struct u300_gpio_confdata *conf;
+			int offset = (i*8) + j;
+
+			if (plat->variant == U300_GPIO_COH901571_3_BS335)
+				conf = &bs335_gpio_config[i][j];
+			else if (plat->variant == U300_GPIO_COH901571_3_BS365)
+				conf = &bs365_gpio_config[i][j];
+			else
+				break;
+
+			u300_gpio_init_pin(gpio, offset, conf);
+		}
+	}
+}
+
+static inline void u300_gpio_free_ports(struct u300_gpio *gpio)
+{
+	struct u300_gpio_port *port;
+	struct list_head *p, *n;
+
+	list_for_each_safe(p, n, &gpio->port_list) {
+		port = list_entry(p, struct u300_gpio_port, node);
+		list_del(&port->node);
+		free_irq(port->irq, port);
+		kfree(port);
+	}
+}
+
+static int __init u300_gpio_probe(struct platform_device *pdev)
+{
+	struct u300_gpio_platform *plat = dev_get_platdata(&pdev->dev);
+	struct u300_gpio *gpio;
+	int err = 0;
+	int portno;
+	u32 val;
+	u32 ifr;
+	int i;
+
+	gpio = kzalloc(sizeof(struct u300_gpio), GFP_KERNEL);
+	if (gpio == NULL) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	gpio->chip = u300_gpio_chip;
+	gpio->chip.ngpio = plat->ports * U300_GPIO_PINS_PER_PORT;
+	gpio->irq_base = plat->gpio_irq_base;
+	gpio->chip.dev = &pdev->dev;
+	gpio->chip.base = plat->gpio_base;
+	gpio->dev = &pdev->dev;
+
+	/* Get GPIO clock */
+	gpio->clk = 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");
+		goto err_no_clk;
+	}
+	err = clk_enable(gpio->clk);
+	if (err) {
+		dev_err(gpio->dev, "could not enable GPIO clock\n");
+		goto err_no_clk_enable;
+	}
+
+	gpio->memres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!gpio->memres) {
+		dev_err(gpio->dev, "could not get GPIO memory resource\n");
+		err = -ENODEV;
+		goto err_no_resource;
+	}
+
+	if (!request_mem_region(gpio->memres->start,
+				resource_size(gpio->memres),
+				"GPIO Controller")) {
+		err = -ENODEV;
+		goto err_no_ioregion;
+	}
+
+	gpio->base = ioremap(gpio->memres->start, resource_size(gpio->memres));
+	if (!gpio->base) {
+		err = -ENOMEM;
+		goto err_no_ioremap;
+	}
+
+	if (plat->variant == U300_GPIO_COH901335) {
+		dev_info(gpio->dev,
+			 "initializing GPIO Controller COH 901 335\n");
+		gpio->stride = U300_335_PORT_STRIDE;
+		gpio->pcr = U300_335_PXPCR;
+		gpio->dor = U300_335_PXPDOR;
+		gpio->dir = U300_335_PXPDIR;
+		gpio->per = U300_335_PXPER;
+		gpio->icr = U300_335_PXICR;
+		gpio->ien = U300_335_PXIEN;
+		gpio->iev = U300_335_PXIEV;
+		ifr = U300_335_PXIFR;
+
+		/* Turn on the GPIO block */
+		writel(U300_335_CR_BLOCK_CLOCK_ENABLE,
+		       gpio->base + U300_335_CR);
+	} else if (plat->variant == U300_GPIO_COH901571_3_BS335 ||
+		   plat->variant == U300_GPIO_COH901571_3_BS365) {
+		dev_info(gpio->dev,
+			 "initializing GPIO Controller COH 901 571/3\n");
+		gpio->stride = U300_571_PORT_STRIDE;
+		gpio->pcr = U300_571_PXPCR;
+		gpio->dor = U300_571_PXPDOR;
+		gpio->dir = U300_571_PXPDIR;
+		gpio->per = U300_571_PXPER;
+		gpio->icr = U300_571_PXICR;
+		gpio->ien = U300_571_PXIEN;
+		gpio->iev = U300_571_PXIEV;
+		ifr = U300_571_PXIFR;
+
+		val = readl(gpio->base + U300_571_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_571_CR_BLOCK_CLKRQ_ENABLE,
+		       gpio->base + U300_571_CR);
+		u300_gpio_init_coh901571(gpio, plat);
+	} else {
+		dev_err(gpio->dev, "unknown block variant\n");
+		err = -ENODEV;
+		goto err_unknown_variant;
+	}
+
+	/* Add each port with its IRQ separately */
+	INIT_LIST_HEAD(&gpio->port_list);
+	for (portno = 0 ; portno < plat->ports; portno++) {
+		struct u300_gpio_port *port =
+			kmalloc(sizeof(struct u300_gpio_port), GFP_KERNEL);
+
+		if (!port) {
+			dev_err(gpio->dev, "out of memory\n");
+			err = -ENOMEM;
+			goto err_no_port;
+		}
+
+		snprintf(port->name, 8, "gpio%d", portno);
+		port->number = portno;
+		port->gpio = gpio;
+
+		port->irq = platform_get_irq_byname(pdev,
+						    port->name);
+
+		dev_dbg(gpio->dev, "register IRQ %d for %s\n", port->irq,
+			port->name);
+
+		irq_set_chained_handler(port->irq, u300_gpio_irq_handler);
+		irq_set_handler_data(port->irq, port);
+
+		/* For each GPIO pin set the unique IRQ handler */
+		for (i = 0; i < U300_GPIO_PINS_PER_PORT; i++) {
+			int irqno = gpio->irq_base + (portno << 3) + i;
+
+			dev_dbg(gpio->dev, "handler for IRQ %d on %s\n",
+				irqno, port->name);
+			irq_set_chip_and_handler(irqno, &u300_gpio_irqchip,
+						 handle_simple_irq);
+			set_irq_flags(irqno, IRQF_VALID);
+			irq_set_chip_data(irqno, port);
+		}
+
+		/* Turns off irq force (test register) for this port */
+		writel(0x0, gpio->base + portno * gpio->stride + ifr);
+
+		list_add_tail(&port->node, &gpio->port_list);
+	}
+	dev_dbg(gpio->dev, "initialized %d GPIO ports\n", portno);
+
+	err = gpiochip_add(&gpio->chip);
+	if (err) {
+		dev_err(gpio->dev, "unable to add gpiochip: %d\n", err);
+		goto err_no_chip;
+	}
+
+	platform_set_drvdata(pdev, gpio);
+
+	return 0;
+
+err_no_chip:
+err_no_port:
+	u300_gpio_free_ports(gpio);
+err_unknown_variant:
+	iounmap(gpio->base);
+err_no_ioremap:
+	release_mem_region(gpio->memres->start, resource_size(gpio->memres));
+err_no_ioregion:
+err_no_resource:
+	clk_disable(gpio->clk);
+err_no_clk_enable:
+	clk_put(gpio->clk);
+err_no_clk:
+	kfree(gpio);
+	dev_info(&pdev->dev, "module ERROR:%d\n", err);
+	return err;
+}
+
+static int __exit u300_gpio_remove(struct platform_device *pdev)
+{
+	struct u300_gpio_platform *plat = dev_get_platdata(&pdev->dev);
+	struct u300_gpio *gpio = platform_get_drvdata(pdev);
+	int err;
+
+	/* Turn off the GPIO block */
+	if (plat->variant == U300_GPIO_COH901335)
+		writel(0x00000000U, gpio->base + U300_335_CR);
+	if (plat->variant == U300_GPIO_COH901571_3_BS335 ||
+	    plat->variant == U300_GPIO_COH901571_3_BS365)
+		writel(0x00000000U, gpio->base + U300_571_CR);
+
+	err = gpiochip_remove(&gpio->chip);
+	if (err < 0) {
+		dev_err(gpio->dev, "unable to remove gpiochip: %d\n", err);
+		return err;
+	}
+	u300_gpio_free_ports(gpio);
+	iounmap(gpio->base);
+	release_mem_region(gpio->memres->start,
+			   resource_size(gpio->memres));
+	clk_disable(gpio->clk);
+	clk_put(gpio->clk);
+	platform_set_drvdata(pdev, NULL);
+	kfree(gpio);
+	return 0;
+}
+
+static struct platform_driver u300_gpio_driver = {
+	.driver		= {
+		.name	= "u300-gpio",
+	},
+	.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");