gpio: move the Nomadik GPIO driver to pinctrl

I'm moving this driver over to the pinctrl subsystem to convert
the custom pin mux/config scheme over to use pinctrl.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 1306 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-nomadik.c b/drivers/pinctrl/pinctrl-nomadik.c
new file mode 100644
index 000000000000..9b126b6d79cc
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-nomadik.c
@@ -0,0 +1,1306 @@
+/*
+ * Generic GPIO driver for logic cells found in the Nomadik SoC
+ *
+ * Copyright (C) 2008,2009 STMicroelectronics
+ * Copyright (C) 2009 Alessandro Rubini <rubini@unipv.it>
+ *   Rewritten based on work by Prafulla WADASKAR <prafulla.wadaskar@st.com>
+ * Copyright (C) 2011 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/slab.h>
+
+#include <asm/mach/irq.h>
+
+#include <plat/pincfg.h>
+#include <plat/gpio-nomadik.h>
+
+/*
+ * The GPIO module in the Nomadik family of Systems-on-Chip is an
+ * AMBA device, managing 32 pins and alternate functions.  The logic block
+ * is currently used in the Nomadik and ux500.
+ *
+ * Symbols in this file are called "nmk_gpio" for "nomadik gpio"
+ */
+
+#define NMK_GPIO_PER_CHIP	32
+
+struct nmk_gpio_chip {
+	struct gpio_chip chip;
+	struct irq_domain *domain;
+	void __iomem *addr;
+	struct clk *clk;
+	unsigned int bank;
+	unsigned int parent_irq;
+	int secondary_parent_irq;
+	u32 (*get_secondary_status)(unsigned int bank);
+	void (*set_ioforce)(bool enable);
+	spinlock_t lock;
+	bool sleepmode;
+	/* Keep track of configured edges */
+	u32 edge_rising;
+	u32 edge_falling;
+	u32 real_wake;
+	u32 rwimsc;
+	u32 fwimsc;
+	u32 rimsc;
+	u32 fimsc;
+	u32 pull_up;
+	u32 lowemi;
+};
+
+static struct nmk_gpio_chip *
+nmk_gpio_chips[DIV_ROUND_UP(ARCH_NR_GPIOS, NMK_GPIO_PER_CHIP)];
+
+static DEFINE_SPINLOCK(nmk_gpio_slpm_lock);
+
+#define NUM_BANKS ARRAY_SIZE(nmk_gpio_chips)
+
+static void __nmk_gpio_set_mode(struct nmk_gpio_chip *nmk_chip,
+				unsigned offset, int gpio_mode)
+{
+	u32 bit = 1 << offset;
+	u32 afunc, bfunc;
+
+	afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & ~bit;
+	bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & ~bit;
+	if (gpio_mode & NMK_GPIO_ALT_A)
+		afunc |= bit;
+	if (gpio_mode & NMK_GPIO_ALT_B)
+		bfunc |= bit;
+	writel(afunc, nmk_chip->addr + NMK_GPIO_AFSLA);
+	writel(bfunc, nmk_chip->addr + NMK_GPIO_AFSLB);
+}
+
+static void __nmk_gpio_set_slpm(struct nmk_gpio_chip *nmk_chip,
+				unsigned offset, enum nmk_gpio_slpm mode)
+{
+	u32 bit = 1 << offset;
+	u32 slpm;
+
+	slpm = readl(nmk_chip->addr + NMK_GPIO_SLPC);
+	if (mode == NMK_GPIO_SLPM_NOCHANGE)
+		slpm |= bit;
+	else
+		slpm &= ~bit;
+	writel(slpm, nmk_chip->addr + NMK_GPIO_SLPC);
+}
+
+static void __nmk_gpio_set_pull(struct nmk_gpio_chip *nmk_chip,
+				unsigned offset, enum nmk_gpio_pull pull)
+{
+	u32 bit = 1 << offset;
+	u32 pdis;
+
+	pdis = readl(nmk_chip->addr + NMK_GPIO_PDIS);
+	if (pull == NMK_GPIO_PULL_NONE) {
+		pdis |= bit;
+		nmk_chip->pull_up &= ~bit;
+	} else {
+		pdis &= ~bit;
+	}
+
+	writel(pdis, nmk_chip->addr + NMK_GPIO_PDIS);
+
+	if (pull == NMK_GPIO_PULL_UP) {
+		nmk_chip->pull_up |= bit;
+		writel(bit, nmk_chip->addr + NMK_GPIO_DATS);
+	} else if (pull == NMK_GPIO_PULL_DOWN) {
+		nmk_chip->pull_up &= ~bit;
+		writel(bit, nmk_chip->addr + NMK_GPIO_DATC);
+	}
+}
+
+static void __nmk_gpio_set_lowemi(struct nmk_gpio_chip *nmk_chip,
+				  unsigned offset, bool lowemi)
+{
+	u32 bit = BIT(offset);
+	bool enabled = nmk_chip->lowemi & bit;
+
+	if (lowemi == enabled)
+		return;
+
+	if (lowemi)
+		nmk_chip->lowemi |= bit;
+	else
+		nmk_chip->lowemi &= ~bit;
+
+	writel_relaxed(nmk_chip->lowemi,
+		       nmk_chip->addr + NMK_GPIO_LOWEMI);
+}
+
+static void __nmk_gpio_make_input(struct nmk_gpio_chip *nmk_chip,
+				  unsigned offset)
+{
+	writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC);
+}
+
+static void __nmk_gpio_set_output(struct nmk_gpio_chip *nmk_chip,
+				  unsigned offset, int val)
+{
+	if (val)
+		writel(1 << offset, nmk_chip->addr + NMK_GPIO_DATS);
+	else
+		writel(1 << offset, nmk_chip->addr + NMK_GPIO_DATC);
+}
+
+static void __nmk_gpio_make_output(struct nmk_gpio_chip *nmk_chip,
+				  unsigned offset, int val)
+{
+	writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRS);
+	__nmk_gpio_set_output(nmk_chip, offset, val);
+}
+
+static void __nmk_gpio_set_mode_safe(struct nmk_gpio_chip *nmk_chip,
+				     unsigned offset, int gpio_mode,
+				     bool glitch)
+{
+	u32 rwimsc = nmk_chip->rwimsc;
+	u32 fwimsc = nmk_chip->fwimsc;
+
+	if (glitch && nmk_chip->set_ioforce) {
+		u32 bit = BIT(offset);
+
+		/* Prevent spurious wakeups */
+		writel(rwimsc & ~bit, nmk_chip->addr + NMK_GPIO_RWIMSC);
+		writel(fwimsc & ~bit, nmk_chip->addr + NMK_GPIO_FWIMSC);
+
+		nmk_chip->set_ioforce(true);
+	}
+
+	__nmk_gpio_set_mode(nmk_chip, offset, gpio_mode);
+
+	if (glitch && nmk_chip->set_ioforce) {
+		nmk_chip->set_ioforce(false);
+
+		writel(rwimsc, nmk_chip->addr + NMK_GPIO_RWIMSC);
+		writel(fwimsc, nmk_chip->addr + NMK_GPIO_FWIMSC);
+	}
+}
+
+static void
+nmk_gpio_disable_lazy_irq(struct nmk_gpio_chip *nmk_chip, unsigned offset)
+{
+	u32 falling = nmk_chip->fimsc & BIT(offset);
+	u32 rising = nmk_chip->rimsc & BIT(offset);
+	int gpio = nmk_chip->chip.base + offset;
+	int irq = NOMADIK_GPIO_TO_IRQ(gpio);
+	struct irq_data *d = irq_get_irq_data(irq);
+
+	if (!rising && !falling)
+		return;
+
+	if (!d || !irqd_irq_disabled(d))
+		return;
+
+	if (rising) {
+		nmk_chip->rimsc &= ~BIT(offset);
+		writel_relaxed(nmk_chip->rimsc,
+			       nmk_chip->addr + NMK_GPIO_RIMSC);
+	}
+
+	if (falling) {
+		nmk_chip->fimsc &= ~BIT(offset);
+		writel_relaxed(nmk_chip->fimsc,
+			       nmk_chip->addr + NMK_GPIO_FIMSC);
+	}
+
+	dev_dbg(nmk_chip->chip.dev, "%d: clearing interrupt mask\n", gpio);
+}
+
+static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
+			     pin_cfg_t cfg, bool sleep, unsigned int *slpmregs)
+{
+	static const char *afnames[] = {
+		[NMK_GPIO_ALT_GPIO]	= "GPIO",
+		[NMK_GPIO_ALT_A]	= "A",
+		[NMK_GPIO_ALT_B]	= "B",
+		[NMK_GPIO_ALT_C]	= "C"
+	};
+	static const char *pullnames[] = {
+		[NMK_GPIO_PULL_NONE]	= "none",
+		[NMK_GPIO_PULL_UP]	= "up",
+		[NMK_GPIO_PULL_DOWN]	= "down",
+		[3] /* illegal */	= "??"
+	};
+	static const char *slpmnames[] = {
+		[NMK_GPIO_SLPM_INPUT]		= "input/wakeup",
+		[NMK_GPIO_SLPM_NOCHANGE]	= "no-change/no-wakeup",
+	};
+
+	int pin = PIN_NUM(cfg);
+	int pull = PIN_PULL(cfg);
+	int af = PIN_ALT(cfg);
+	int slpm = PIN_SLPM(cfg);
+	int output = PIN_DIR(cfg);
+	int val = PIN_VAL(cfg);
+	bool glitch = af == NMK_GPIO_ALT_C;
+
+	dev_dbg(nmk_chip->chip.dev, "pin %d [%#lx]: af %s, pull %s, slpm %s (%s%s)\n",
+		pin, cfg, afnames[af], pullnames[pull], slpmnames[slpm],
+		output ? "output " : "input",
+		output ? (val ? "high" : "low") : "");
+
+	if (sleep) {
+		int slpm_pull = PIN_SLPM_PULL(cfg);
+		int slpm_output = PIN_SLPM_DIR(cfg);
+		int slpm_val = PIN_SLPM_VAL(cfg);
+
+		af = NMK_GPIO_ALT_GPIO;
+
+		/*
+		 * The SLPM_* values are normal values + 1 to allow zero to
+		 * mean "same as normal".
+		 */
+		if (slpm_pull)
+			pull = slpm_pull - 1;
+		if (slpm_output)
+			output = slpm_output - 1;
+		if (slpm_val)
+			val = slpm_val - 1;
+
+		dev_dbg(nmk_chip->chip.dev, "pin %d: sleep pull %s, dir %s, val %s\n",
+			pin,
+			slpm_pull ? pullnames[pull] : "same",
+			slpm_output ? (output ? "output" : "input") : "same",
+			slpm_val ? (val ? "high" : "low") : "same");
+	}
+
+	if (output)
+		__nmk_gpio_make_output(nmk_chip, offset, val);
+	else {
+		__nmk_gpio_make_input(nmk_chip, offset);
+		__nmk_gpio_set_pull(nmk_chip, offset, pull);
+	}
+
+	__nmk_gpio_set_lowemi(nmk_chip, offset, PIN_LOWEMI(cfg));
+
+	/*
+	 * If the pin is switching to altfunc, and there was an interrupt
+	 * installed on it which has been lazy disabled, actually mask the
+	 * interrupt to prevent spurious interrupts that would occur while the
+	 * pin is under control of the peripheral.  Only SKE does this.
+	 */
+	if (af != NMK_GPIO_ALT_GPIO)
+		nmk_gpio_disable_lazy_irq(nmk_chip, offset);
+
+	/*
+	 * If we've backed up the SLPM registers (glitch workaround), modify
+	 * the backups since they will be restored.
+	 */
+	if (slpmregs) {
+		if (slpm == NMK_GPIO_SLPM_NOCHANGE)
+			slpmregs[nmk_chip->bank] |= BIT(offset);
+		else
+			slpmregs[nmk_chip->bank] &= ~BIT(offset);
+	} else
+		__nmk_gpio_set_slpm(nmk_chip, offset, slpm);
+
+	__nmk_gpio_set_mode_safe(nmk_chip, offset, af, glitch);
+}
+
+/*
+ * Safe sequence used to switch IOs between GPIO and Alternate-C mode:
+ *  - Save SLPM registers
+ *  - Set SLPM=0 for the IOs you want to switch and others to 1
+ *  - Configure the GPIO registers for the IOs that are being switched
+ *  - Set IOFORCE=1
+ *  - Modify the AFLSA/B registers for the IOs that are being switched
+ *  - Set IOFORCE=0
+ *  - Restore SLPM registers
+ *  - Any spurious wake up event during switch sequence to be ignored and
+ *    cleared
+ */
+static void nmk_gpio_glitch_slpm_init(unsigned int *slpm)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+		unsigned int temp = slpm[i];
+
+		if (!chip)
+			break;
+
+		clk_enable(chip->clk);
+
+		slpm[i] = readl(chip->addr + NMK_GPIO_SLPC);
+		writel(temp, chip->addr + NMK_GPIO_SLPC);
+	}
+}
+
+static void nmk_gpio_glitch_slpm_restore(unsigned int *slpm)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+		if (!chip)
+			break;
+
+		writel(slpm[i], chip->addr + NMK_GPIO_SLPC);
+
+		clk_disable(chip->clk);
+	}
+}
+
+static int __nmk_config_pins(pin_cfg_t *cfgs, int num, bool sleep)
+{
+	static unsigned int slpm[NUM_BANKS];
+	unsigned long flags;
+	bool glitch = false;
+	int ret = 0;
+	int i;
+
+	for (i = 0; i < num; i++) {
+		if (PIN_ALT(cfgs[i]) == NMK_GPIO_ALT_C) {
+			glitch = true;
+			break;
+		}
+	}
+
+	spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+
+	if (glitch) {
+		memset(slpm, 0xff, sizeof(slpm));
+
+		for (i = 0; i < num; i++) {
+			int pin = PIN_NUM(cfgs[i]);
+			int offset = pin % NMK_GPIO_PER_CHIP;
+
+			if (PIN_ALT(cfgs[i]) == NMK_GPIO_ALT_C)
+				slpm[pin / NMK_GPIO_PER_CHIP] &= ~BIT(offset);
+		}
+
+		nmk_gpio_glitch_slpm_init(slpm);
+	}
+
+	for (i = 0; i < num; i++) {
+		struct nmk_gpio_chip *nmk_chip;
+		int pin = PIN_NUM(cfgs[i]);
+
+		nmk_chip = nmk_gpio_chips[pin / NMK_GPIO_PER_CHIP];
+		if (!nmk_chip) {
+			ret = -EINVAL;
+			break;
+		}
+
+		clk_enable(nmk_chip->clk);
+		spin_lock(&nmk_chip->lock);
+		__nmk_config_pin(nmk_chip, pin % NMK_GPIO_PER_CHIP,
+				 cfgs[i], sleep, glitch ? slpm : NULL);
+		spin_unlock(&nmk_chip->lock);
+		clk_disable(nmk_chip->clk);
+	}
+
+	if (glitch)
+		nmk_gpio_glitch_slpm_restore(slpm);
+
+	spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+
+	return ret;
+}
+
+/**
+ * nmk_config_pin - configure a pin's mux attributes
+ * @cfg: pin confguration
+ *
+ * Configures a pin's mode (alternate function or GPIO), its pull up status,
+ * and its sleep mode based on the specified configuration.  The @cfg is
+ * usually one of the SoC specific macros defined in mach/<soc>-pins.h.  These
+ * are constructed using, and can be further enhanced with, the macros in
+ * plat/pincfg.h.
+ *
+ * If a pin's mode is set to GPIO, it is configured as an input to avoid
+ * side-effects.  The gpio can be manipulated later using standard GPIO API
+ * calls.
+ */
+int nmk_config_pin(pin_cfg_t cfg, bool sleep)
+{
+	return __nmk_config_pins(&cfg, 1, sleep);
+}
+EXPORT_SYMBOL(nmk_config_pin);
+
+/**
+ * nmk_config_pins - configure several pins at once
+ * @cfgs: array of pin configurations
+ * @num: number of elments in the array
+ *
+ * Configures several pins using nmk_config_pin().  Refer to that function for
+ * further information.
+ */
+int nmk_config_pins(pin_cfg_t *cfgs, int num)
+{
+	return __nmk_config_pins(cfgs, num, false);
+}
+EXPORT_SYMBOL(nmk_config_pins);
+
+int nmk_config_pins_sleep(pin_cfg_t *cfgs, int num)
+{
+	return __nmk_config_pins(cfgs, num, true);
+}
+EXPORT_SYMBOL(nmk_config_pins_sleep);
+
+/**
+ * nmk_gpio_set_slpm() - configure the sleep mode of a pin
+ * @gpio: pin number
+ * @mode: NMK_GPIO_SLPM_INPUT or NMK_GPIO_SLPM_NOCHANGE,
+ *
+ * This register is actually in the pinmux layer, not the GPIO block itself.
+ * The GPIO1B_SLPM register defines the GPIO mode when SLEEP/DEEP-SLEEP
+ * mode is entered (i.e. when signal IOFORCE is HIGH by the platform code).
+ * Each GPIO can be configured to be forced into GPIO mode when IOFORCE is
+ * HIGH, overriding the normal setting defined by GPIO_AFSELx registers.
+ * When IOFORCE returns LOW (by software, after SLEEP/DEEP-SLEEP exit),
+ * the GPIOs return to the normal setting defined by GPIO_AFSELx registers.
+ *
+ * If @mode is NMK_GPIO_SLPM_INPUT, the corresponding GPIO is switched to GPIO
+ * mode when signal IOFORCE is HIGH (i.e. when SLEEP/DEEP-SLEEP mode is
+ * entered) regardless of the altfunction selected. Also wake-up detection is
+ * ENABLED.
+ *
+ * If @mode is NMK_GPIO_SLPM_NOCHANGE, the corresponding GPIO remains
+ * controlled by NMK_GPIO_DATC, NMK_GPIO_DATS, NMK_GPIO_DIR, NMK_GPIO_PDIS
+ * (for altfunction GPIO) or respective on-chip peripherals (for other
+ * altfuncs) when IOFORCE is HIGH. Also wake-up detection DISABLED.
+ *
+ * Note that enable_irq_wake() will automatically enable wakeup detection.
+ */
+int nmk_gpio_set_slpm(int gpio, enum nmk_gpio_slpm mode)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+
+	nmk_chip = nmk_gpio_chips[gpio / NMK_GPIO_PER_CHIP];
+	if (!nmk_chip)
+		return -EINVAL;
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+	spin_lock(&nmk_chip->lock);
+
+	__nmk_gpio_set_slpm(nmk_chip, gpio % NMK_GPIO_PER_CHIP, mode);
+
+	spin_unlock(&nmk_chip->lock);
+	spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+/**
+ * nmk_gpio_set_pull() - enable/disable pull up/down on a gpio
+ * @gpio: pin number
+ * @pull: one of NMK_GPIO_PULL_DOWN, NMK_GPIO_PULL_UP, and NMK_GPIO_PULL_NONE
+ *
+ * Enables/disables pull up/down on a specified pin.  This only takes effect if
+ * the pin is configured as an input (either explicitly or by the alternate
+ * function).
+ *
+ * NOTE: If enabling the pull up/down, the caller must ensure that the GPIO is
+ * configured as an input.  Otherwise, due to the way the controller registers
+ * work, this function will change the value output on the pin.
+ */
+int nmk_gpio_set_pull(int gpio, enum nmk_gpio_pull pull)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+
+	nmk_chip = nmk_gpio_chips[gpio / NMK_GPIO_PER_CHIP];
+	if (!nmk_chip)
+		return -EINVAL;
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_chip->lock, flags);
+	__nmk_gpio_set_pull(nmk_chip, gpio % NMK_GPIO_PER_CHIP, pull);
+	spin_unlock_irqrestore(&nmk_chip->lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+/* Mode functions */
+/**
+ * nmk_gpio_set_mode() - set the mux mode of a gpio pin
+ * @gpio: pin number
+ * @gpio_mode: one of NMK_GPIO_ALT_GPIO, NMK_GPIO_ALT_A,
+ *	       NMK_GPIO_ALT_B, and NMK_GPIO_ALT_C
+ *
+ * Sets the mode of the specified pin to one of the alternate functions or
+ * plain GPIO.
+ */
+int nmk_gpio_set_mode(int gpio, int gpio_mode)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+
+	nmk_chip = nmk_gpio_chips[gpio / NMK_GPIO_PER_CHIP];
+	if (!nmk_chip)
+		return -EINVAL;
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_chip->lock, flags);
+	__nmk_gpio_set_mode(nmk_chip, gpio % NMK_GPIO_PER_CHIP, gpio_mode);
+	spin_unlock_irqrestore(&nmk_chip->lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+EXPORT_SYMBOL(nmk_gpio_set_mode);
+
+int nmk_gpio_get_mode(int gpio)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	u32 afunc, bfunc, bit;
+
+	nmk_chip = nmk_gpio_chips[gpio / NMK_GPIO_PER_CHIP];
+	if (!nmk_chip)
+		return -EINVAL;
+
+	bit = 1 << (gpio % NMK_GPIO_PER_CHIP);
+
+	clk_enable(nmk_chip->clk);
+
+	afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & bit;
+	bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & bit;
+
+	clk_disable(nmk_chip->clk);
+
+	return (afunc ? NMK_GPIO_ALT_A : 0) | (bfunc ? NMK_GPIO_ALT_B : 0);
+}
+EXPORT_SYMBOL(nmk_gpio_get_mode);
+
+
+/* IRQ functions */
+static inline int nmk_gpio_get_bitmask(int gpio)
+{
+	return 1 << (gpio % NMK_GPIO_PER_CHIP);
+}
+
+static void nmk_gpio_irq_ack(struct irq_data *d)
+{
+	struct nmk_gpio_chip *nmk_chip;
+
+	nmk_chip = irq_data_get_irq_chip_data(d);
+	if (!nmk_chip)
+		return;
+
+	clk_enable(nmk_chip->clk);
+	writel(nmk_gpio_get_bitmask(d->hwirq), nmk_chip->addr + NMK_GPIO_IC);
+	clk_disable(nmk_chip->clk);
+}
+
+enum nmk_gpio_irq_type {
+	NORMAL,
+	WAKE,
+};
+
+static void __nmk_gpio_irq_modify(struct nmk_gpio_chip *nmk_chip,
+				  int gpio, enum nmk_gpio_irq_type which,
+				  bool enable)
+{
+	u32 bitmask = nmk_gpio_get_bitmask(gpio);
+	u32 *rimscval;
+	u32 *fimscval;
+	u32 rimscreg;
+	u32 fimscreg;
+
+	if (which == NORMAL) {
+		rimscreg = NMK_GPIO_RIMSC;
+		fimscreg = NMK_GPIO_FIMSC;
+		rimscval = &nmk_chip->rimsc;
+		fimscval = &nmk_chip->fimsc;
+	} else  {
+		rimscreg = NMK_GPIO_RWIMSC;
+		fimscreg = NMK_GPIO_FWIMSC;
+		rimscval = &nmk_chip->rwimsc;
+		fimscval = &nmk_chip->fwimsc;
+	}
+
+	/* we must individually set/clear the two edges */
+	if (nmk_chip->edge_rising & bitmask) {
+		if (enable)
+			*rimscval |= bitmask;
+		else
+			*rimscval &= ~bitmask;
+		writel(*rimscval, nmk_chip->addr + rimscreg);
+	}
+	if (nmk_chip->edge_falling & bitmask) {
+		if (enable)
+			*fimscval |= bitmask;
+		else
+			*fimscval &= ~bitmask;
+		writel(*fimscval, nmk_chip->addr + fimscreg);
+	}
+}
+
+static void __nmk_gpio_set_wake(struct nmk_gpio_chip *nmk_chip,
+				int gpio, bool on)
+{
+	/*
+	 * Ensure WAKEUP_ENABLE is on.  No need to disable it if wakeup is
+	 * disabled, since setting SLPM to 1 increases power consumption, and
+	 * wakeup is anyhow controlled by the RIMSC and FIMSC registers.
+	 */
+	if (nmk_chip->sleepmode && on) {
+		__nmk_gpio_set_slpm(nmk_chip, gpio % nmk_chip->chip.base,
+				    NMK_GPIO_SLPM_WAKEUP_ENABLE);
+	}
+
+	__nmk_gpio_irq_modify(nmk_chip, gpio, WAKE, on);
+}
+
+static int nmk_gpio_irq_maskunmask(struct irq_data *d, bool enable)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+	u32 bitmask;
+
+	nmk_chip = irq_data_get_irq_chip_data(d);
+	bitmask = nmk_gpio_get_bitmask(d->hwirq);
+	if (!nmk_chip)
+		return -EINVAL;
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+	spin_lock(&nmk_chip->lock);
+
+	__nmk_gpio_irq_modify(nmk_chip, d->hwirq, NORMAL, enable);
+
+	if (!(nmk_chip->real_wake & bitmask))
+		__nmk_gpio_set_wake(nmk_chip, d->hwirq, enable);
+
+	spin_unlock(&nmk_chip->lock);
+	spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+static void nmk_gpio_irq_mask(struct irq_data *d)
+{
+	nmk_gpio_irq_maskunmask(d, false);
+}
+
+static void nmk_gpio_irq_unmask(struct irq_data *d)
+{
+	nmk_gpio_irq_maskunmask(d, true);
+}
+
+static int nmk_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+	u32 bitmask;
+
+	nmk_chip = irq_data_get_irq_chip_data(d);
+	if (!nmk_chip)
+		return -EINVAL;
+	bitmask = nmk_gpio_get_bitmask(d->hwirq);
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+	spin_lock(&nmk_chip->lock);
+
+	if (irqd_irq_disabled(d))
+		__nmk_gpio_set_wake(nmk_chip, d->hwirq, on);
+
+	if (on)
+		nmk_chip->real_wake |= bitmask;
+	else
+		nmk_chip->real_wake &= ~bitmask;
+
+	spin_unlock(&nmk_chip->lock);
+	spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+static int nmk_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	bool enabled = !irqd_irq_disabled(d);
+	bool wake = irqd_is_wakeup_set(d);
+	struct nmk_gpio_chip *nmk_chip;
+	unsigned long flags;
+	u32 bitmask;
+
+	nmk_chip = irq_data_get_irq_chip_data(d);
+	bitmask = nmk_gpio_get_bitmask(d->hwirq);
+	if (!nmk_chip)
+		return -EINVAL;
+	if (type & IRQ_TYPE_LEVEL_HIGH)
+		return -EINVAL;
+	if (type & IRQ_TYPE_LEVEL_LOW)
+		return -EINVAL;
+
+	clk_enable(nmk_chip->clk);
+	spin_lock_irqsave(&nmk_chip->lock, flags);
+
+	if (enabled)
+		__nmk_gpio_irq_modify(nmk_chip, d->hwirq, NORMAL, false);
+
+	if (enabled || wake)
+		__nmk_gpio_irq_modify(nmk_chip, d->hwirq, WAKE, false);
+
+	nmk_chip->edge_rising &= ~bitmask;
+	if (type & IRQ_TYPE_EDGE_RISING)
+		nmk_chip->edge_rising |= bitmask;
+
+	nmk_chip->edge_falling &= ~bitmask;
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		nmk_chip->edge_falling |= bitmask;
+
+	if (enabled)
+		__nmk_gpio_irq_modify(nmk_chip, d->hwirq, NORMAL, true);
+
+	if (enabled || wake)
+		__nmk_gpio_irq_modify(nmk_chip, d->hwirq, WAKE, true);
+
+	spin_unlock_irqrestore(&nmk_chip->lock, flags);
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+static unsigned int nmk_gpio_irq_startup(struct irq_data *d)
+{
+	struct nmk_gpio_chip *nmk_chip = irq_data_get_irq_chip_data(d);
+
+	clk_enable(nmk_chip->clk);
+	nmk_gpio_irq_unmask(d);
+	return 0;
+}
+
+static void nmk_gpio_irq_shutdown(struct irq_data *d)
+{
+	struct nmk_gpio_chip *nmk_chip = irq_data_get_irq_chip_data(d);
+
+	nmk_gpio_irq_mask(d);
+	clk_disable(nmk_chip->clk);
+}
+
+static struct irq_chip nmk_gpio_irq_chip = {
+	.name		= "Nomadik-GPIO",
+	.irq_ack	= nmk_gpio_irq_ack,
+	.irq_mask	= nmk_gpio_irq_mask,
+	.irq_unmask	= nmk_gpio_irq_unmask,
+	.irq_set_type	= nmk_gpio_irq_set_type,
+	.irq_set_wake	= nmk_gpio_irq_set_wake,
+	.irq_startup	= nmk_gpio_irq_startup,
+	.irq_shutdown	= nmk_gpio_irq_shutdown,
+};
+
+static void __nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc,
+				   u32 status)
+{
+	struct nmk_gpio_chip *nmk_chip;
+	struct irq_chip *host_chip = irq_get_chip(irq);
+	unsigned int first_irq;
+
+	chained_irq_enter(host_chip, desc);
+
+	nmk_chip = irq_get_handler_data(irq);
+	first_irq = nmk_chip->domain->revmap_data.legacy.first_irq;
+	while (status) {
+		int bit = __ffs(status);
+
+		generic_handle_irq(first_irq + bit);
+		status &= ~BIT(bit);
+	}
+
+	chained_irq_exit(host_chip, desc);
+}
+
+static void nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct nmk_gpio_chip *nmk_chip = irq_get_handler_data(irq);
+	u32 status;
+
+	clk_enable(nmk_chip->clk);
+	status = readl(nmk_chip->addr + NMK_GPIO_IS);
+	clk_disable(nmk_chip->clk);
+
+	__nmk_gpio_irq_handler(irq, desc, status);
+}
+
+static void nmk_gpio_secondary_irq_handler(unsigned int irq,
+					   struct irq_desc *desc)
+{
+	struct nmk_gpio_chip *nmk_chip = irq_get_handler_data(irq);
+	u32 status = nmk_chip->get_secondary_status(nmk_chip->bank);
+
+	__nmk_gpio_irq_handler(irq, desc, status);
+}
+
+static int nmk_gpio_init_irq(struct nmk_gpio_chip *nmk_chip)
+{
+	irq_set_chained_handler(nmk_chip->parent_irq, nmk_gpio_irq_handler);
+	irq_set_handler_data(nmk_chip->parent_irq, nmk_chip);
+
+	if (nmk_chip->secondary_parent_irq >= 0) {
+		irq_set_chained_handler(nmk_chip->secondary_parent_irq,
+					nmk_gpio_secondary_irq_handler);
+		irq_set_handler_data(nmk_chip->secondary_parent_irq, nmk_chip);
+	}
+
+	return 0;
+}
+
+/* I/O Functions */
+static int nmk_gpio_make_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+
+	clk_enable(nmk_chip->clk);
+
+	writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC);
+
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+static int nmk_gpio_get_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+	u32 bit = 1 << offset;
+	int value;
+
+	clk_enable(nmk_chip->clk);
+
+	value = (readl(nmk_chip->addr + NMK_GPIO_DAT) & bit) != 0;
+
+	clk_disable(nmk_chip->clk);
+
+	return value;
+}
+
+static void nmk_gpio_set_output(struct gpio_chip *chip, unsigned offset,
+				int val)
+{
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+
+	clk_enable(nmk_chip->clk);
+
+	__nmk_gpio_set_output(nmk_chip, offset, val);
+
+	clk_disable(nmk_chip->clk);
+}
+
+static int nmk_gpio_make_output(struct gpio_chip *chip, unsigned offset,
+				int val)
+{
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+
+	clk_enable(nmk_chip->clk);
+
+	__nmk_gpio_make_output(nmk_chip, offset, val);
+
+	clk_disable(nmk_chip->clk);
+
+	return 0;
+}
+
+static int nmk_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+
+	return irq_find_mapping(nmk_chip->domain, offset);
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/seq_file.h>
+
+static void nmk_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+	int mode;
+	unsigned		i;
+	unsigned		gpio = chip->base;
+	int			is_out;
+	struct nmk_gpio_chip *nmk_chip =
+		container_of(chip, struct nmk_gpio_chip, chip);
+	const char *modes[] = {
+		[NMK_GPIO_ALT_GPIO]	= "gpio",
+		[NMK_GPIO_ALT_A]	= "altA",
+		[NMK_GPIO_ALT_B]	= "altB",
+		[NMK_GPIO_ALT_C]	= "altC",
+	};
+
+	clk_enable(nmk_chip->clk);
+
+	for (i = 0; i < chip->ngpio; i++, gpio++) {
+		const char *label = gpiochip_is_requested(chip, i);
+		bool pull;
+		u32 bit = 1 << i;
+
+		is_out = readl(nmk_chip->addr + NMK_GPIO_DIR) & bit;
+		pull = !(readl(nmk_chip->addr + NMK_GPIO_PDIS) & bit);
+		mode = nmk_gpio_get_mode(gpio);
+		seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s %s",
+			gpio, label ?: "(none)",
+			is_out ? "out" : "in ",
+			chip->get
+				? (chip->get(chip, i) ? "hi" : "lo")
+				: "?  ",
+			(mode < 0) ? "unknown" : modes[mode],
+			pull ? "pull" : "none");
+
+		if (label && !is_out) {
+			int		irq = gpio_to_irq(gpio);
+			struct irq_desc	*desc = irq_to_desc(irq);
+
+			/* This races with request_irq(), set_irq_type(),
+			 * and set_irq_wake() ... but those are "rare".
+			 */
+			if (irq >= 0 && desc->action) {
+				char *trigger;
+				u32 bitmask = nmk_gpio_get_bitmask(gpio);
+
+				if (nmk_chip->edge_rising & bitmask)
+					trigger = "edge-rising";
+				else if (nmk_chip->edge_falling & bitmask)
+					trigger = "edge-falling";
+				else
+					trigger = "edge-undefined";
+
+				seq_printf(s, " irq-%d %s%s",
+					irq, trigger,
+					irqd_is_wakeup_set(&desc->irq_data)
+						? " wakeup" : "");
+			}
+		}
+
+		seq_printf(s, "\n");
+	}
+
+	clk_disable(nmk_chip->clk);
+}
+
+#else
+#define nmk_gpio_dbg_show	NULL
+#endif
+
+/* This structure is replicated for each GPIO block allocated at probe time */
+static struct gpio_chip nmk_gpio_template = {
+	.direction_input	= nmk_gpio_make_input,
+	.get			= nmk_gpio_get_input,
+	.direction_output	= nmk_gpio_make_output,
+	.set			= nmk_gpio_set_output,
+	.to_irq			= nmk_gpio_to_irq,
+	.dbg_show		= nmk_gpio_dbg_show,
+	.can_sleep		= 0,
+};
+
+void nmk_gpio_clocks_enable(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+		if (!chip)
+			continue;
+
+		clk_enable(chip->clk);
+	}
+}
+
+void nmk_gpio_clocks_disable(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+		if (!chip)
+			continue;
+
+		clk_disable(chip->clk);
+	}
+}
+
+/*
+ * Called from the suspend/resume path to only keep the real wakeup interrupts
+ * (those that have had set_irq_wake() called on them) as wakeup interrupts,
+ * and not the rest of the interrupts which we needed to have as wakeups for
+ * cpuidle.
+ *
+ * PM ops are not used since this needs to be done at the end, after all the
+ * other drivers are done with their suspend callbacks.
+ */
+void nmk_gpio_wakeups_suspend(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+		if (!chip)
+			break;
+
+		clk_enable(chip->clk);
+
+		writel(chip->rwimsc & chip->real_wake,
+		       chip->addr + NMK_GPIO_RWIMSC);
+		writel(chip->fwimsc & chip->real_wake,
+		       chip->addr + NMK_GPIO_FWIMSC);
+
+		clk_disable(chip->clk);
+	}
+}
+
+void nmk_gpio_wakeups_resume(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_BANKS; i++) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+		if (!chip)
+			break;
+
+		clk_enable(chip->clk);
+
+		writel(chip->rwimsc, chip->addr + NMK_GPIO_RWIMSC);
+		writel(chip->fwimsc, chip->addr + NMK_GPIO_FWIMSC);
+
+		clk_disable(chip->clk);
+	}
+}
+
+/*
+ * Read the pull up/pull down status.
+ * A bit set in 'pull_up' means that pull up
+ * is selected if pull is enabled in PDIS register.
+ * Note: only pull up/down set via this driver can
+ * be detected due to HW limitations.
+ */
+void nmk_gpio_read_pull(int gpio_bank, u32 *pull_up)
+{
+	if (gpio_bank < NUM_BANKS) {
+		struct nmk_gpio_chip *chip = nmk_gpio_chips[gpio_bank];
+
+		if (!chip)
+			return;
+
+		*pull_up = chip->pull_up;
+	}
+}
+
+int nmk_gpio_irq_map(struct irq_domain *d, unsigned int irq,
+			  irq_hw_number_t hwirq)
+{
+	struct nmk_gpio_chip *nmk_chip = d->host_data;
+
+	if (!nmk_chip)
+		return -EINVAL;
+
+	irq_set_chip_and_handler(irq, &nmk_gpio_irq_chip, handle_edge_irq);
+	set_irq_flags(irq, IRQF_VALID);
+	irq_set_chip_data(irq, nmk_chip);
+	irq_set_irq_type(irq, IRQ_TYPE_EDGE_FALLING);
+
+	return 0;
+}
+
+const struct irq_domain_ops nmk_gpio_irq_simple_ops = {
+	.map = nmk_gpio_irq_map,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+static int __devinit nmk_gpio_probe(struct platform_device *dev)
+{
+	struct nmk_gpio_platform_data *pdata = dev->dev.platform_data;
+	struct device_node *np = dev->dev.of_node;
+	struct nmk_gpio_chip *nmk_chip;
+	struct gpio_chip *chip;
+	struct resource *res;
+	struct clk *clk;
+	int secondary_irq;
+	void __iomem *base;
+	int irq;
+	int ret;
+
+	if (!pdata && !np) {
+		dev_err(&dev->dev, "No platform data or device tree found\n");
+		return -ENODEV;
+	}
+
+	if (np) {
+		pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+
+		if (of_get_property(np, "supports-sleepmode", NULL))
+			pdata->supports_sleepmode = true;
+
+		if (of_property_read_u32(np, "gpio-bank", &dev->id)) {
+			dev_err(&dev->dev, "gpio-bank property not found\n");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		pdata->first_gpio = dev->id * NMK_GPIO_PER_CHIP;
+		pdata->num_gpio   = NMK_GPIO_PER_CHIP;
+	}
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto out;
+	}
+
+	secondary_irq = platform_get_irq(dev, 1);
+	if (secondary_irq >= 0 && !pdata->get_secondary_status) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (request_mem_region(res->start, resource_size(res),
+			       dev_name(&dev->dev)) == NULL) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	base = ioremap(res->start, resource_size(res));
+	if (!base) {
+		ret = -ENOMEM;
+		goto out_release;
+	}
+
+	clk = clk_get(&dev->dev, NULL);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto out_unmap;
+	}
+
+	nmk_chip = kzalloc(sizeof(*nmk_chip), GFP_KERNEL);
+	if (!nmk_chip) {
+		ret = -ENOMEM;
+		goto out_clk;
+	}
+
+	/*
+	 * The virt address in nmk_chip->addr is in the nomadik register space,
+	 * so we can simply convert the resource address, without remapping
+	 */
+	nmk_chip->bank = dev->id;
+	nmk_chip->clk = clk;
+	nmk_chip->addr = base;
+	nmk_chip->chip = nmk_gpio_template;
+	nmk_chip->parent_irq = irq;
+	nmk_chip->secondary_parent_irq = secondary_irq;
+	nmk_chip->get_secondary_status = pdata->get_secondary_status;
+	nmk_chip->set_ioforce = pdata->set_ioforce;
+	nmk_chip->sleepmode = pdata->supports_sleepmode;
+	spin_lock_init(&nmk_chip->lock);
+
+	chip = &nmk_chip->chip;
+	chip->base = pdata->first_gpio;
+	chip->ngpio = pdata->num_gpio;
+	chip->label = pdata->name ?: dev_name(&dev->dev);
+	chip->dev = &dev->dev;
+	chip->owner = THIS_MODULE;
+
+	clk_enable(nmk_chip->clk);
+	nmk_chip->lowemi = readl_relaxed(nmk_chip->addr + NMK_GPIO_LOWEMI);
+	clk_disable(nmk_chip->clk);
+
+	chip->of_node = np;
+
+	ret = gpiochip_add(&nmk_chip->chip);
+	if (ret)
+		goto out_free;
+
+	BUG_ON(nmk_chip->bank >= ARRAY_SIZE(nmk_gpio_chips));
+
+	nmk_gpio_chips[nmk_chip->bank] = nmk_chip;
+
+	platform_set_drvdata(dev, nmk_chip);
+
+	nmk_chip->domain = irq_domain_add_legacy(np, NMK_GPIO_PER_CHIP,
+						NOMADIK_GPIO_TO_IRQ(pdata->first_gpio),
+						0, &nmk_gpio_irq_simple_ops, nmk_chip);
+	if (!nmk_chip->domain) {
+		pr_err("%s: Failed to create irqdomain\n", np->full_name);
+		ret = -ENOSYS;
+		goto out_free;
+	}
+
+	nmk_gpio_init_irq(nmk_chip);
+
+	dev_info(&dev->dev, "at address %p\n", nmk_chip->addr);
+
+	return 0;
+
+out_free:
+	kfree(nmk_chip);
+out_clk:
+	clk_disable(clk);
+	clk_put(clk);
+out_unmap:
+	iounmap(base);
+out_release:
+	release_mem_region(res->start, resource_size(res));
+out:
+	dev_err(&dev->dev, "Failure %i for GPIO %i-%i\n", ret,
+		  pdata->first_gpio, pdata->first_gpio+31);
+	if (np)
+		kfree(pdata);
+
+	return ret;
+}
+
+static const struct of_device_id nmk_gpio_match[] = {
+	{ .compatible = "st,nomadik-gpio", },
+	{}
+};
+
+static struct platform_driver nmk_gpio_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "gpio",
+		.of_match_table = nmk_gpio_match,
+	},
+	.probe = nmk_gpio_probe,
+};
+
+static int __init nmk_gpio_init(void)
+{
+	return platform_driver_register(&nmk_gpio_driver);
+}
+
+core_initcall(nmk_gpio_init);
+
+MODULE_AUTHOR("Prafulla WADASKAR and Alessandro Rubini");
+MODULE_DESCRIPTION("Nomadik GPIO Driver");
+MODULE_LICENSE("GPL");