// SPDX-License-Identifier: GPL-2.0-only
/*
 * Support functions for OMAP GPIO
 *
 * Copyright (C) 2003-2005 Nokia Corporation
 * Written by Juha Yrjölä <juha.yrjola@nokia.com>
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/syscore_ops.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpu_pm.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/gpio/driver.h>
#include <linux/bitops.h>
#include <linux/platform_data/gpio-omap.h>

#define OMAP4_GPIO_DEBOUNCINGTIME_MASK 0xFF

struct gpio_regs {
        u32 sysconfig;
        u32 irqenable1;
        u32 irqenable2;
        u32 wake_en;
        u32 ctrl;
        u32 oe;
        u32 leveldetect0;
        u32 leveldetect1;
        u32 risingdetect;
        u32 fallingdetect;
        u32 dataout;
        u32 debounce;
        u32 debounce_en;
};

struct gpio_bank {
        void __iomem *base;
        const struct omap_gpio_reg_offs *regs;

        int irq;
        u32 non_wakeup_gpios;
        u32 enabled_non_wakeup_gpios;
        struct gpio_regs context;
        u32 saved_datain;
        u32 level_mask;
        u32 toggle_mask;
        raw_spinlock_t lock;
        raw_spinlock_t wa_lock;
        struct gpio_chip chip;
        struct clk *dbck;
        struct notifier_block nb;
        unsigned int is_suspended:1;
        unsigned int needs_resume:1;
        u32 mod_usage;
        u32 irq_usage;
        u32 dbck_enable_mask;
        bool dbck_enabled;
        bool is_mpuio;
        bool dbck_flag;
        bool loses_context;
        bool context_valid;
        int stride;
        u32 width;
        int context_loss_count;

        void (*set_dataout)(struct gpio_bank *bank, unsigned gpio, int enable);
        int (*get_context_loss_count)(struct device *dev);
};

#define GPIO_MOD_CTRL_BIT       BIT(0)

#define BANK_USED(bank) (bank->mod_usage || bank->irq_usage)
#define LINE_USED(line, offset) (line & (BIT(offset)))

static void omap_gpio_unmask_irq(struct irq_data *d);

static inline struct gpio_bank *omap_irq_data_get_bank(struct irq_data *d)
{
        struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
        return gpiochip_get_data(chip);
}

static inline u32 omap_gpio_rmw(void __iomem *reg, u32 mask, bool set)
{
        u32 val = readl_relaxed(reg);

        if (set)
                val |= mask;
        else
                val &= ~mask;

        writel_relaxed(val, reg);

        return val;
}

static void omap_set_gpio_direction(struct gpio_bank *bank, int gpio,
                                    int is_input)
{
        bank->context.oe = omap_gpio_rmw(bank->base + bank->regs->direction,
                                         BIT(gpio), is_input);
}


/* set data out value using dedicate set/clear register */
static void omap_set_gpio_dataout_reg(struct gpio_bank *bank, unsigned offset,
                                      int enable)
{
        void __iomem *reg = bank->base;
        u32 l = BIT(offset);

        if (enable) {
                reg += bank->regs->set_dataout;
                bank->context.dataout |= l;
        } else {
                reg += bank->regs->clr_dataout;
                bank->context.dataout &= ~l;
        }

        writel_relaxed(l, reg);
}

/* set data out value using mask register */
static void omap_set_gpio_dataout_mask(struct gpio_bank *bank, unsigned offset,
                                       int enable)
{
        bank->context.dataout = omap_gpio_rmw(bank->base + bank->regs->dataout,
                                              BIT(offset), enable);
}

static inline void omap_gpio_dbck_enable(struct gpio_bank *bank)
{
        if (bank->dbck_enable_mask && !bank->dbck_enabled) {
                clk_enable(bank->dbck);
                bank->dbck_enabled = true;

                writel_relaxed(bank->dbck_enable_mask,
                             bank->base + bank->regs->debounce_en);
        }
}

static inline void omap_gpio_dbck_disable(struct gpio_bank *bank)
{
        if (bank->dbck_enable_mask && bank->dbck_enabled) {
                /*
                 * Disable debounce before cutting it's clock. If debounce is
                 * enabled but the clock is not, GPIO module seems to be unable
                 * to detect events and generate interrupts at least on OMAP3.
                 */
                writel_relaxed(0, bank->base + bank->regs->debounce_en);

                clk_disable(bank->dbck);
                bank->dbck_enabled = false;
        }
}

/**
 * omap2_set_gpio_debounce - low level gpio debounce time
 * @bank: the gpio bank we're acting upon
 * @offset: the gpio number on this @bank
 * @debounce: debounce time to use
 *
 * OMAP's debounce time is in 31us steps
 *   <debounce time> = (GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) x 31
 * so we need to convert and round up to the closest unit.
 *
 * Return: 0 on success, negative error otherwise.
 */
static int omap2_set_gpio_debounce(struct gpio_bank *bank, unsigned offset,
                                   unsigned debounce)
{
        u32                     val;
        u32                     l;
        bool                    enable = !!debounce;

        if (!bank->dbck_flag)
                return -ENOTSUPP;

        if (enable) {
                debounce = DIV_ROUND_UP(debounce, 31) - 1;
                if ((debounce & OMAP4_GPIO_DEBOUNCINGTIME_MASK) != debounce)
                        return -EINVAL;
        }

        l = BIT(offset);

        clk_enable(bank->dbck);
        writel_relaxed(debounce, bank->base + bank->regs->debounce);

        val = omap_gpio_rmw(bank->base + bank->regs->debounce_en, l, enable);
        bank->dbck_enable_mask = val;

        clk_disable(bank->dbck);
        /*
         * Enable debounce clock per module.
         * This call is mandatory because in omap_gpio_request() when
         * *_runtime_get_sync() is called,  _gpio_dbck_enable() within
         * runtime callbck fails to turn on dbck because dbck_enable_mask
         * used within _gpio_dbck_enable() is still not initialized at
         * that point. Therefore we have to enable dbck here.
         */
        omap_gpio_dbck_enable(bank);
        if (bank->dbck_enable_mask) {
                bank->context.debounce = debounce;
                bank->context.debounce_en = val;
        }

        return 0;
}

/**
 * omap_clear_gpio_debounce - clear debounce settings for a gpio
 * @bank: the gpio bank we're acting upon
 * @offset: the gpio number on this @bank
 *
 * If a gpio is using debounce, then clear the debounce enable bit and if
 * this is the only gpio in this bank using debounce, then clear the debounce
 * time too. The debounce clock will also be disabled when calling this function
 * if this is the only gpio in the bank using debounce.
 */
static void omap_clear_gpio_debounce(struct gpio_bank *bank, unsigned offset)
{
        u32 gpio_bit = BIT(offset);

        if (!bank->dbck_flag)
                return;

        if (!(bank->dbck_enable_mask & gpio_bit))
                return;

        bank->dbck_enable_mask &= ~gpio_bit;
        bank->context.debounce_en &= ~gpio_bit;
        writel_relaxed(bank->context.debounce_en,
                     bank->base + bank->regs->debounce_en);

        if (!bank->dbck_enable_mask) {
                bank->context.debounce = 0;
                writel_relaxed(bank->context.debounce, bank->base +
                             bank->regs->debounce);
                clk_disable(bank->dbck);
                bank->dbck_enabled = false;
        }
}

/*
 * Off mode wake-up capable GPIOs in bank(s) that are in the wakeup domain.
 * See TRM section for GPIO for "Wake-Up Generation" for the list of GPIOs
 * in wakeup domain. If bank->non_wakeup_gpios is not configured, assume none
 * are capable waking up the system from off mode.
 */
static bool omap_gpio_is_off_wakeup_capable(struct gpio_bank *bank, u32 gpio_mask)
{
        u32 no_wake = bank->non_wakeup_gpios;

        if (no_wake)
                return !!(~no_wake & gpio_mask);

        return false;
}

static inline void omap_set_gpio_trigger(struct gpio_bank *bank, int gpio,
                                                unsigned trigger)
{
        void __iomem *base = bank->base;
        u32 gpio_bit = BIT(gpio);

        omap_gpio_rmw(base + bank->regs->leveldetect0, gpio_bit,
                      trigger & IRQ_TYPE_LEVEL_LOW);
        omap_gpio_rmw(base + bank->regs->leveldetect1, gpio_bit,
                      trigger & IRQ_TYPE_LEVEL_HIGH);

        /*
         * We need the edge detection enabled for to allow the GPIO block
         * to be woken from idle state.  Set the appropriate edge detection
         * in addition to the level detection.
         */
        omap_gpio_rmw(base + bank->regs->risingdetect, gpio_bit,
                      trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH));
        omap_gpio_rmw(base + bank->regs->fallingdetect, gpio_bit,
                      trigger & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_LEVEL_LOW));

        bank->context.leveldetect0 =
                        readl_relaxed(bank->base + bank->regs->leveldetect0);
        bank->context.leveldetect1 =
                        readl_relaxed(bank->base + bank->regs->leveldetect1);
        bank->context.risingdetect =
                        readl_relaxed(bank->base + bank->regs->risingdetect);
        bank->context.fallingdetect =
                        readl_relaxed(bank->base + bank->regs->fallingdetect);

        bank->level_mask = bank->context.leveldetect0 |
                           bank->context.leveldetect1;

        /* This part needs to be executed always for OMAP{34xx, 44xx} */
        if (!bank->regs->irqctrl && !omap_gpio_is_off_wakeup_capable(bank, gpio)) {
                /*
                 * Log the edge gpio and manually trigger the IRQ
                 * after resume if the input level changes
                 * to avoid irq lost during PER RET/OFF mode
                 * Applies for omap2 non-wakeup gpio and all omap3 gpios
                 */
                if (trigger & IRQ_TYPE_EDGE_BOTH)
                        bank->enabled_non_wakeup_gpios |= gpio_bit;
                else
                        bank->enabled_non_wakeup_gpios &= ~gpio_bit;
        }
}

/*
 * This only applies to chips that can't do both rising and falling edge
 * detection at once.  For all other chips, this function is a noop.
 */
static void omap_toggle_gpio_edge_triggering(struct gpio_bank *bank, int gpio)
{
        if (IS_ENABLED(CONFIG_ARCH_OMAP1) && bank->regs->irqctrl) {
                void __iomem *reg = bank->base + bank->regs->irqctrl;

                writel_relaxed(readl_relaxed(reg) ^ BIT(gpio), reg);
        }
}

static int omap_set_gpio_triggering(struct gpio_bank *bank, int gpio,
                                    unsigned trigger)
{
        void __iomem *reg = bank->base;
        u32 l = 0;

        if (bank->regs->leveldetect0 && bank->regs->wkup_en) {
                omap_set_gpio_trigger(bank, gpio, trigger);
        } else if (bank->regs->irqctrl) {
                reg += bank->regs->irqctrl;

                l = readl_relaxed(reg);
                if ((trigger & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH)
                        bank->toggle_mask |= BIT(gpio);
                if (trigger & IRQ_TYPE_EDGE_RISING)
                        l |= BIT(gpio);
                else if (trigger & IRQ_TYPE_EDGE_FALLING)
                        l &= ~(BIT(gpio));
                else
                        return -EINVAL;

                writel_relaxed(l, reg);
        } else if (bank->regs->edgectrl1) {
                if (gpio & 0x08)
                        reg += bank->regs->edgectrl2;
                else
                        reg += bank->regs->edgectrl1;

                gpio &= 0x07;
                l = readl_relaxed(reg);
                l &= ~(3 << (gpio << 1));
                if (trigger & IRQ_TYPE_EDGE_RISING)
                        l |= 2 << (gpio << 1);
                if (trigger & IRQ_TYPE_EDGE_FALLING)
                        l |= BIT(gpio << 1);
                writel_relaxed(l, reg);
        }
        return 0;
}

static void omap_enable_gpio_module(struct gpio_bank *bank, unsigned offset)
{
        if (bank->regs->pinctrl) {
                void __iomem *reg = bank->base + bank->regs->pinctrl;

                /* Claim the pin for MPU */
                writel_relaxed(readl_relaxed(reg) | (BIT(offset)), reg);
        }

        if (bank->regs->ctrl && !BANK_USED(bank)) {
                void __iomem *reg = bank->base + bank->regs->ctrl;
                u32 ctrl;

                ctrl = readl_relaxed(reg);
                /* Module is enabled, clocks are not gated */
                ctrl &= ~GPIO_MOD_CTRL_BIT;
                writel_relaxed(ctrl, reg);
                bank->context.ctrl = ctrl;
        }
}

static void omap_disable_gpio_module(struct gpio_bank *bank, unsigned offset)
{
        if (bank->regs->ctrl && !BANK_USED(bank)) {
                void __iomem *reg = bank->base + bank->regs->ctrl;
                u32 ctrl;

                ctrl = readl_relaxed(reg);
                /* Module is disabled, clocks are gated */
                ctrl |= GPIO_MOD_CTRL_BIT;
                writel_relaxed(ctrl, reg);
                bank->context.ctrl = ctrl;
        }
}

static int omap_gpio_is_input(struct gpio_bank *bank, unsigned offset)
{
        void __iomem *reg = bank->base + bank->regs->direction;

        return readl_relaxed(reg) & BIT(offset);
}

static void omap_gpio_init_irq(struct gpio_bank *bank, unsigned offset)
{
        if (!LINE_USED(bank->mod_usage, offset)) {
                omap_enable_gpio_module(bank, offset);
                omap_set_gpio_direction(bank, offset, 1);
        }
        bank->irq_usage |= BIT(offset);
}

static int omap_gpio_irq_type(struct irq_data *d, unsigned type)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);
        int retval;
        unsigned long flags;
        unsigned offset = d->hwirq;

        if (type & ~IRQ_TYPE_SENSE_MASK)
                return -EINVAL;

        if (!bank->regs->leveldetect0 &&
                (type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
                return -EINVAL;

        raw_spin_lock_irqsave(&bank->lock, flags);
        retval = omap_set_gpio_triggering(bank, offset, type);
        if (retval) {
                raw_spin_unlock_irqrestore(&bank->lock, flags);
                goto error;
        }
        omap_gpio_init_irq(bank, offset);
        if (!omap_gpio_is_input(bank, offset)) {
                raw_spin_unlock_irqrestore(&bank->lock, flags);
                retval = -EINVAL;
                goto error;
        }
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
                irq_set_handler_locked(d, handle_level_irq);
        else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
                /*
                 * Edge IRQs are already cleared/acked in irq_handler and
                 * not need to be masked, as result handle_edge_irq()
                 * logic is excessed here and may cause lose of interrupts.
                 * So just use handle_simple_irq.
                 */
                irq_set_handler_locked(d, handle_simple_irq);

        return 0;

error:
        return retval;
}

static void omap_clear_gpio_irqbank(struct gpio_bank *bank, int gpio_mask)
{
        void __iomem *reg = bank->base;

        reg += bank->regs->irqstatus;
        writel_relaxed(gpio_mask, reg);

        /* Workaround for clearing DSP GPIO interrupts to allow retention */
        if (bank->regs->irqstatus2) {
                reg = bank->base + bank->regs->irqstatus2;
                writel_relaxed(gpio_mask, reg);
        }

        /* Flush posted write for the irq status to avoid spurious interrupts */
        readl_relaxed(reg);
}

static inline void omap_clear_gpio_irqstatus(struct gpio_bank *bank,
                                             unsigned offset)
{
        omap_clear_gpio_irqbank(bank, BIT(offset));
}

static u32 omap_get_gpio_irqbank_mask(struct gpio_bank *bank)
{
        void __iomem *reg = bank->base;
        u32 l;
        u32 mask = (BIT(bank->width)) - 1;

        reg += bank->regs->irqenable;
        l = readl_relaxed(reg);
        if (bank->regs->irqenable_inv)
                l = ~l;
        l &= mask;
        return l;
}

static inline void omap_set_gpio_irqenable(struct gpio_bank *bank,
                                           unsigned offset, int enable)
{
        void __iomem *reg = bank->base;
        u32 gpio_mask = BIT(offset);

        if (bank->regs->set_irqenable && bank->regs->clr_irqenable) {
                if (enable) {
                        reg += bank->regs->set_irqenable;
                        bank->context.irqenable1 |= gpio_mask;
                } else {
                        reg += bank->regs->clr_irqenable;
                        bank->context.irqenable1 &= ~gpio_mask;
                }
                writel_relaxed(gpio_mask, reg);
        } else {
                bank->context.irqenable1 =
                        omap_gpio_rmw(reg + bank->regs->irqenable, gpio_mask,
                                      enable ^ bank->regs->irqenable_inv);
        }

        /*
         * Program GPIO wakeup along with IRQ enable to satisfy OMAP4430 TRM
         * note requiring correlation between the IRQ enable registers and
         * the wakeup registers.  In any case, we want wakeup from idle
         * enabled for the GPIOs which support this feature.
         */
        if (bank->regs->wkup_en &&
            (bank->regs->edgectrl1 || !(bank->non_wakeup_gpios & gpio_mask))) {
                bank->context.wake_en =
                        omap_gpio_rmw(bank->base + bank->regs->wkup_en,
                                      gpio_mask, enable);
        }
}

/* Use disable_irq_wake() and enable_irq_wake() functions from drivers */
static int omap_gpio_wake_enable(struct irq_data *d, unsigned int enable)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);

        return irq_set_irq_wake(bank->irq, enable);
}

/*
 * We need to unmask the GPIO bank interrupt as soon as possible to
 * avoid missing GPIO interrupts for other lines in the bank.
 * Then we need to mask-read-clear-unmask the triggered GPIO lines
 * in the bank to avoid missing nested interrupts for a GPIO line.
 * If we wait to unmask individual GPIO lines in the bank after the
 * line's interrupt handler has been run, we may miss some nested
 * interrupts.
 */
static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank)
{
        void __iomem *isr_reg = NULL;
        u32 enabled, isr, edge;
        unsigned int bit;
        struct gpio_bank *bank = gpiobank;
        unsigned long wa_lock_flags;
        unsigned long lock_flags;

        isr_reg = bank->base + bank->regs->irqstatus;
        if (WARN_ON(!isr_reg))
                goto exit;

        if (WARN_ONCE(!pm_runtime_active(bank->chip.parent),
                      "gpio irq%i while runtime suspended?\n", irq))
                return IRQ_NONE;

        while (1) {
                raw_spin_lock_irqsave(&bank->lock, lock_flags);

                enabled = omap_get_gpio_irqbank_mask(bank);
                isr = readl_relaxed(isr_reg) & enabled;

                /*
                 * Clear edge sensitive interrupts before calling handler(s)
                 * so subsequent edge transitions are not missed while the
                 * handlers are running.
                 */
                edge = isr & ~bank->level_mask;
                if (edge)
                        omap_clear_gpio_irqbank(bank, edge);

                raw_spin_unlock_irqrestore(&bank->lock, lock_flags);

                if (!isr)
                        break;

                while (isr) {
                        bit = __ffs(isr);
                        isr &= ~(BIT(bit));

                        raw_spin_lock_irqsave(&bank->lock, lock_flags);
                        /*
                         * Some chips can't respond to both rising and falling
                         * at the same time.  If this irq was requested with
                         * both flags, we need to flip the ICR data for the IRQ
                         * to respond to the IRQ for the opposite direction.
                         * This will be indicated in the bank toggle_mask.
                         */
                        if (bank->toggle_mask & (BIT(bit)))
                                omap_toggle_gpio_edge_triggering(bank, bit);

                        raw_spin_unlock_irqrestore(&bank->lock, lock_flags);

                        raw_spin_lock_irqsave(&bank->wa_lock, wa_lock_flags);

                        generic_handle_irq(irq_find_mapping(bank->chip.irq.domain,
                                                            bit));

                        raw_spin_unlock_irqrestore(&bank->wa_lock,
                                                   wa_lock_flags);
                }
        }
exit:
        return IRQ_HANDLED;
}

static unsigned int omap_gpio_irq_startup(struct irq_data *d)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);
        unsigned long flags;
        unsigned offset = d->hwirq;

        raw_spin_lock_irqsave(&bank->lock, flags);

        if (!LINE_USED(bank->mod_usage, offset))
                omap_set_gpio_direction(bank, offset, 1);
        omap_enable_gpio_module(bank, offset);
        bank->irq_usage |= BIT(offset);

        raw_spin_unlock_irqrestore(&bank->lock, flags);
        omap_gpio_unmask_irq(d);

        return 0;
}

static void omap_gpio_irq_shutdown(struct irq_data *d)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);
        unsigned long flags;
        unsigned offset = d->hwirq;

        raw_spin_lock_irqsave(&bank->lock, flags);
        bank->irq_usage &= ~(BIT(offset));
        omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
        omap_clear_gpio_irqstatus(bank, offset);
        omap_set_gpio_irqenable(bank, offset, 0);
        if (!LINE_USED(bank->mod_usage, offset))
                omap_clear_gpio_debounce(bank, offset);
        omap_disable_gpio_module(bank, offset);
        raw_spin_unlock_irqrestore(&bank->lock, flags);
}

static void omap_gpio_irq_bus_lock(struct irq_data *data)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(data);

        pm_runtime_get_sync(bank->chip.parent);
}

static void gpio_irq_bus_sync_unlock(struct irq_data *data)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(data);

        pm_runtime_put(bank->chip.parent);
}

static void omap_gpio_mask_irq(struct irq_data *d)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);
        unsigned offset = d->hwirq;
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
        omap_set_gpio_irqenable(bank, offset, 0);
        raw_spin_unlock_irqrestore(&bank->lock, flags);
}

static void omap_gpio_unmask_irq(struct irq_data *d)
{
        struct gpio_bank *bank = omap_irq_data_get_bank(d);
        unsigned offset = d->hwirq;
        u32 trigger = irqd_get_trigger_type(d);
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_set_gpio_irqenable(bank, offset, 1);

        /*
         * For level-triggered GPIOs, clearing must be done after the source
         * is cleared, thus after the handler has run. OMAP4 needs this done
         * after enabing the interrupt to clear the wakeup status.
         */
        if (bank->regs->leveldetect0 && bank->regs->wkup_en &&
            trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
                omap_clear_gpio_irqstatus(bank, offset);

        if (trigger)
                omap_set_gpio_triggering(bank, offset, trigger);

        raw_spin_unlock_irqrestore(&bank->lock, flags);
}

/*---------------------------------------------------------------------*/

static int omap_mpuio_suspend_noirq(struct device *dev)
{
        struct gpio_bank        *bank = dev_get_drvdata(dev);
        void __iomem            *mask_reg = bank->base +
                                        OMAP_MPUIO_GPIO_MASKIT / bank->stride;
        unsigned long           flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        writel_relaxed(0xffff & ~bank->context.wake_en, mask_reg);
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return 0;
}

static int omap_mpuio_resume_noirq(struct device *dev)
{
        struct gpio_bank        *bank = dev_get_drvdata(dev);
        void __iomem            *mask_reg = bank->base +
                                        OMAP_MPUIO_GPIO_MASKIT / bank->stride;
        unsigned long           flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        writel_relaxed(bank->context.wake_en, mask_reg);
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return 0;
}

static const struct dev_pm_ops omap_mpuio_dev_pm_ops = {
        .suspend_noirq = omap_mpuio_suspend_noirq,
        .resume_noirq = omap_mpuio_resume_noirq,
};

/* use platform_driver for this. */
static struct platform_driver omap_mpuio_driver = {
        .driver         = {
                .name   = "mpuio",
                .pm     = &omap_mpuio_dev_pm_ops,
        },
};

static struct platform_device omap_mpuio_device = {
        .name           = "mpuio",
        .id             = -1,
        .dev = {
                .driver = &omap_mpuio_driver.driver,
        }
        /* could list the /proc/iomem resources */
};

static inline void omap_mpuio_init(struct gpio_bank *bank)
{
        platform_set_drvdata(&omap_mpuio_device, bank);

        if (platform_driver_register(&omap_mpuio_driver) == 0)
                (void) platform_device_register(&omap_mpuio_device);
}

/*---------------------------------------------------------------------*/

static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);
        unsigned long flags;

        pm_runtime_get_sync(chip->parent);

        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_enable_gpio_module(bank, offset);
        bank->mod_usage |= BIT(offset);
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return 0;
}

static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        bank->mod_usage &= ~(BIT(offset));
        if (!LINE_USED(bank->irq_usage, offset)) {
                omap_set_gpio_direction(bank, offset, 1);
                omap_clear_gpio_debounce(bank, offset);
        }
        omap_disable_gpio_module(bank, offset);
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        pm_runtime_put(chip->parent);
}

static int omap_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);

        if (readl_relaxed(bank->base + bank->regs->direction) & BIT(offset))
                return GPIO_LINE_DIRECTION_IN;

        return GPIO_LINE_DIRECTION_OUT;
}

static int omap_gpio_input(struct gpio_chip *chip, unsigned offset)
{
        struct gpio_bank *bank;
        unsigned long flags;

        bank = gpiochip_get_data(chip);
        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_set_gpio_direction(bank, offset, 1);
        raw_spin_unlock_irqrestore(&bank->lock, flags);
        return 0;
}

static int omap_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);
        void __iomem *reg;

        if (omap_gpio_is_input(bank, offset))
                reg = bank->base + bank->regs->datain;
        else
                reg = bank->base + bank->regs->dataout;

        return (readl_relaxed(reg) & BIT(offset)) != 0;
}

static int omap_gpio_output(struct gpio_chip *chip, unsigned offset, int value)
{
        struct gpio_bank *bank;
        unsigned long flags;

        bank = gpiochip_get_data(chip);
        raw_spin_lock_irqsave(&bank->lock, flags);
        bank->set_dataout(bank, offset, value);
        omap_set_gpio_direction(bank, offset, 0);
        raw_spin_unlock_irqrestore(&bank->lock, flags);
        return 0;
}

static int omap_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
                                  unsigned long *bits)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);
        void __iomem *base = bank->base;
        u32 direction, m, val = 0;

        direction = readl_relaxed(base + bank->regs->direction);

        m = direction & *mask;
        if (m)
                val |= readl_relaxed(base + bank->regs->datain) & m;

        m = ~direction & *mask;
        if (m)
                val |= readl_relaxed(base + bank->regs->dataout) & m;

        *bits = val;

        return 0;
}

static int omap_gpio_debounce(struct gpio_chip *chip, unsigned offset,
                              unsigned debounce)
{
        struct gpio_bank *bank;
        unsigned long flags;
        int ret;

        bank = gpiochip_get_data(chip);

        raw_spin_lock_irqsave(&bank->lock, flags);
        ret = omap2_set_gpio_debounce(bank, offset, debounce);
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        if (ret)
                dev_info(chip->parent,
                         "Could not set line %u debounce to %u microseconds (%d)",
                         offset, debounce, ret);

        return ret;
}

static int omap_gpio_set_config(struct gpio_chip *chip, unsigned offset,
                                unsigned long config)
{
        u32 debounce;
        int ret = -ENOTSUPP;

        switch (pinconf_to_config_param(config)) {
        case PIN_CONFIG_BIAS_DISABLE:
        case PIN_CONFIG_BIAS_PULL_UP:
        case PIN_CONFIG_BIAS_PULL_DOWN:
                ret = gpiochip_generic_config(chip, offset, config);
                break;
        case PIN_CONFIG_INPUT_DEBOUNCE:
                debounce = pinconf_to_config_argument(config);
                ret = omap_gpio_debounce(chip, offset, debounce);
                break;
        default:
                break;
        }

        return ret;
}

static void omap_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
        struct gpio_bank *bank;
        unsigned long flags;

        bank = gpiochip_get_data(chip);
        raw_spin_lock_irqsave(&bank->lock, flags);
        bank->set_dataout(bank, offset, value);
        raw_spin_unlock_irqrestore(&bank->lock, flags);
}

static void omap_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
                                   unsigned long *bits)
{
        struct gpio_bank *bank = gpiochip_get_data(chip);
        void __iomem *reg = bank->base + bank->regs->dataout;
        unsigned long flags;
        u32 l;

        raw_spin_lock_irqsave(&bank->lock, flags);
        l = (readl_relaxed(reg) & ~*mask) | (*bits & *mask);
        writel_relaxed(l, reg);
        bank->context.dataout = l;
        raw_spin_unlock_irqrestore(&bank->lock, flags);
}

/*---------------------------------------------------------------------*/

static void omap_gpio_show_rev(struct gpio_bank *bank)
{
        static bool called;
        u32 rev;

        if (called || bank->regs->revision == USHRT_MAX)
                return;

        rev = readw_relaxed(bank->base + bank->regs->revision);
        pr_info("OMAP GPIO hardware version %d.%d\n",
                (rev >> 4) & 0x0f, rev & 0x0f);

        called = true;
}

static void omap_gpio_mod_init(struct gpio_bank *bank)
{
        void __iomem *base = bank->base;
        u32 l = 0xffffffff;

        if (bank->width == 16)
                l = 0xffff;

        if (bank->is_mpuio) {
                writel_relaxed(l, bank->base + bank->regs->irqenable);
                return;
        }

        omap_gpio_rmw(base + bank->regs->irqenable, l,
                      bank->regs->irqenable_inv);
        omap_gpio_rmw(base + bank->regs->irqstatus, l,
                      !bank->regs->irqenable_inv);
        if (bank->regs->debounce_en)
                writel_relaxed(0, base + bank->regs->debounce_en);

        /* Save OE default value (0xffffffff) in the context */
        bank->context.oe = readl_relaxed(bank->base + bank->regs->direction);
         /* Initialize interface clk ungated, module enabled */
        if (bank->regs->ctrl)
                writel_relaxed(0, base + bank->regs->ctrl);
}

static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
{
        struct gpio_irq_chip *irq;
        static int gpio;
        const char *label;
        int irq_base = 0;
        int ret;

        /*
         * REVISIT eventually switch from OMAP-specific gpio structs
         * over to the generic ones

         */
        bank->chip.request = omap_gpio_request;
        bank->chip.free = omap_gpio_free;
        bank->chip.get_direction = omap_gpio_get_direction;
        bank->chip.direction_input = omap_gpio_input;
        bank->chip.get = omap_gpio_get;
        bank->chip.get_multiple = omap_gpio_get_multiple;
        bank->chip.direction_output = omap_gpio_output;
        bank->chip.set_config = omap_gpio_set_config;
        bank->chip.set = omap_gpio_set;
        bank->chip.set_multiple = omap_gpio_set_multiple;
        if (bank->is_mpuio) {
                bank->chip.label = "mpuio";
                if (bank->regs->wkup_en)
                        bank->chip.parent = &omap_mpuio_device.dev;
                bank->chip.base = OMAP_MPUIO(0);
        } else {
                label = devm_kasprintf(bank->chip.parent, GFP_KERNEL, "gpio-%d-%d",
                                       gpio, gpio + bank->width - 1);
                if (!label)
                        return -ENOMEM;
                bank->chip.label = label;
                bank->chip.base = gpio;
        }
        bank->chip.ngpio = bank->width;

#ifdef CONFIG_ARCH_OMAP1
        /*
         * REVISIT: Once we have OMAP1 supporting SPARSE_IRQ, we can drop
         * irq_alloc_descs() since a base IRQ offset will no longer be needed.
         */
        irq_base = devm_irq_alloc_descs(bank->chip.parent,
                                        -1, 0, bank->width, 0);
        if (irq_base < 0) {
                dev_err(bank->chip.parent, "Couldn't allocate IRQ numbers\n");
                return -ENODEV;
        }
#endif

        /* MPUIO is a bit different, reading IRQ status clears it */
        if (bank->is_mpuio && !bank->regs->wkup_en)
                irqc->irq_set_wake = NULL;

        irq = &bank->chip.irq;
        irq->chip = irqc;
        irq->handler = handle_bad_irq;
        irq->default_type = IRQ_TYPE_NONE;
        irq->num_parents = 1;
        irq->parents = &bank->irq;
        irq->first = irq_base;

        ret = gpiochip_add_data(&bank->chip, bank);
        if (ret)
                return dev_err_probe(bank->chip.parent, ret, "Could not register gpio chip\n");

        ret = devm_request_irq(bank->chip.parent, bank->irq,
                               omap_gpio_irq_handler,
                               0, dev_name(bank->chip.parent), bank);
        if (ret)
                gpiochip_remove(&bank->chip);

        if (!bank->is_mpuio)
                gpio += bank->width;

        return ret;
}

static void omap_gpio_init_context(struct gpio_bank *p)
{
        const struct omap_gpio_reg_offs *regs = p->regs;
        void __iomem *base = p->base;

        p->context.sysconfig    = readl_relaxed(base + regs->sysconfig);
        p->context.ctrl         = readl_relaxed(base + regs->ctrl);
        p->context.oe           = readl_relaxed(base + regs->direction);
        p->context.wake_en      = readl_relaxed(base + regs->wkup_en);
        p->context.leveldetect0 = readl_relaxed(base + regs->leveldetect0);
        p->context.leveldetect1 = readl_relaxed(base + regs->leveldetect1);
        p->context.risingdetect = readl_relaxed(base + regs->risingdetect);
        p->context.fallingdetect = readl_relaxed(base + regs->fallingdetect);
        p->context.irqenable1   = readl_relaxed(base + regs->irqenable);
        p->context.irqenable2   = readl_relaxed(base + regs->irqenable2);
        p->context.dataout      = readl_relaxed(base + regs->dataout);

        p->context_valid = true;
}

static void omap_gpio_restore_context(struct gpio_bank *bank)
{
        const struct omap_gpio_reg_offs *regs = bank->regs;
        void __iomem *base = bank->base;

        writel_relaxed(bank->context.sysconfig, base + regs->sysconfig);
        writel_relaxed(bank->context.wake_en, base + regs->wkup_en);
        writel_relaxed(bank->context.ctrl, base + regs->ctrl);
        writel_relaxed(bank->context.leveldetect0, base + regs->leveldetect0);
        writel_relaxed(bank->context.leveldetect1, base + regs->leveldetect1);
        writel_relaxed(bank->context.risingdetect, base + regs->risingdetect);
        writel_relaxed(bank->context.fallingdetect, base + regs->fallingdetect);
        writel_relaxed(bank->context.dataout, base + regs->dataout);
        writel_relaxed(bank->context.oe, base + regs->direction);

        if (bank->dbck_enable_mask) {
                writel_relaxed(bank->context.debounce, base + regs->debounce);
                writel_relaxed(bank->context.debounce_en,
                               base + regs->debounce_en);
        }

        writel_relaxed(bank->context.irqenable1, base + regs->irqenable);
        writel_relaxed(bank->context.irqenable2, base + regs->irqenable2);
}

static void omap_gpio_idle(struct gpio_bank *bank, bool may_lose_context)
{
        struct device *dev = bank->chip.parent;
        void __iomem *base = bank->base;
        u32 mask, nowake;

        bank->saved_datain = readl_relaxed(base + bank->regs->datain);

        /* Save syconfig, it's runtime value can be different from init value */
        if (bank->loses_context)
                bank->context.sysconfig = readl_relaxed(base + bank->regs->sysconfig);

        if (!bank->enabled_non_wakeup_gpios)
                goto update_gpio_context_count;

        /* Check for pending EDGE_FALLING, ignore EDGE_BOTH */
        mask = bank->enabled_non_wakeup_gpios & bank->context.fallingdetect;
        mask &= ~bank->context.risingdetect;
        bank->saved_datain |= mask;

        /* Check for pending EDGE_RISING, ignore EDGE_BOTH */
        mask = bank->enabled_non_wakeup_gpios & bank->context.risingdetect;
        mask &= ~bank->context.fallingdetect;
        bank->saved_datain &= ~mask;

        if (!may_lose_context)
                goto update_gpio_context_count;

        /*
         * If going to OFF, remove triggering for all wkup domain
         * non-wakeup GPIOs.  Otherwise spurious IRQs will be
         * generated.  See OMAP2420 Errata item 1.101.
         */
        if (!bank->loses_context && bank->enabled_non_wakeup_gpios) {
                nowake = bank->enabled_non_wakeup_gpios;
                omap_gpio_rmw(base + bank->regs->fallingdetect, nowake, ~nowake);
                omap_gpio_rmw(base + bank->regs->risingdetect, nowake, ~nowake);
        }

update_gpio_context_count:
        if (bank->get_context_loss_count)
                bank->context_loss_count =
                                bank->get_context_loss_count(dev);

        omap_gpio_dbck_disable(bank);
}

static void omap_gpio_unidle(struct gpio_bank *bank)
{
        struct device *dev = bank->chip.parent;
        u32 l = 0, gen, gen0, gen1;
        int c;

        /*
         * On the first resume during the probe, the context has not
         * been initialised and so initialise it now. Also initialise
         * the context loss count.
         */
        if (bank->loses_context && !bank->context_valid) {
                omap_gpio_init_context(bank);

                if (bank->get_context_loss_count)
                        bank->context_loss_count =
                                bank->get_context_loss_count(dev);
        }

        omap_gpio_dbck_enable(bank);

        if (bank->loses_context) {
                if (!bank->get_context_loss_count) {
                        omap_gpio_restore_context(bank);
                } else {
                        c = bank->get_context_loss_count(dev);
                        if (c != bank->context_loss_count) {
                                omap_gpio_restore_context(bank);
                        } else {
                                return;
                        }
                }
        } else {
                /* Restore changes done for OMAP2420 errata 1.101 */
                writel_relaxed(bank->context.fallingdetect,
                               bank->base + bank->regs->fallingdetect);
                writel_relaxed(bank->context.risingdetect,
                               bank->base + bank->regs->risingdetect);
        }

        l = readl_relaxed(bank->base + bank->regs->datain);

        /*
         * Check if any of the non-wakeup interrupt GPIOs have changed
         * state.  If so, generate an IRQ by software.  This is
         * horribly racy, but it's the best we can do to work around
         * this silicon bug.
         */
        l ^= bank->saved_datain;
        l &= bank->enabled_non_wakeup_gpios;

        /*
         * No need to generate IRQs for the rising edge for gpio IRQs
         * configured with falling edge only; and vice versa.
         */
        gen0 = l & bank->context.fallingdetect;
        gen0 &= bank->saved_datain;

        gen1 = l & bank->context.risingdetect;
        gen1 &= ~(bank->saved_datain);

        /* FIXME: Consider GPIO IRQs with level detections properly! */
        gen = l & (~(bank->context.fallingdetect) &
                                         ~(bank->context.risingdetect));
        /* Consider all GPIO IRQs needed to be updated */
        gen |= gen0 | gen1;

        if (gen) {
                u32 old0, old1;

                old0 = readl_relaxed(bank->base + bank->regs->leveldetect0);
                old1 = readl_relaxed(bank->base + bank->regs->leveldetect1);

                if (!bank->regs->irqstatus_raw0) {
                        writel_relaxed(old0 | gen, bank->base +
                                                bank->regs->leveldetect0);
                        writel_relaxed(old1 | gen, bank->base +
                                                bank->regs->leveldetect1);
                }

                if (bank->regs->irqstatus_raw0) {
                        writel_relaxed(old0 | l, bank->base +
                                                bank->regs->leveldetect0);
                        writel_relaxed(old1 | l, bank->base +
                                                bank->regs->leveldetect1);
                }
                writel_relaxed(old0, bank->base + bank->regs->leveldetect0);
                writel_relaxed(old1, bank->base + bank->regs->leveldetect1);
        }
}

static int gpio_omap_cpu_notifier(struct notifier_block *nb,
                                  unsigned long cmd, void *v)
{
        struct gpio_bank *bank;
        unsigned long flags;
        int ret = NOTIFY_OK;
        u32 isr, mask;

        bank = container_of(nb, struct gpio_bank, nb);

        raw_spin_lock_irqsave(&bank->lock, flags);
        if (bank->is_suspended)
                goto out_unlock;

        switch (cmd) {
        case CPU_CLUSTER_PM_ENTER:
                mask = omap_get_gpio_irqbank_mask(bank);
                isr = readl_relaxed(bank->base + bank->regs->irqstatus) & mask;
                if (isr) {
                        ret = NOTIFY_BAD;
                        break;
                }
                omap_gpio_idle(bank, true);
                break;
        case CPU_CLUSTER_PM_ENTER_FAILED:
        case CPU_CLUSTER_PM_EXIT:
                omap_gpio_unidle(bank);
                break;
        }

out_unlock:
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return ret;
}

static const struct omap_gpio_reg_offs omap2_gpio_regs = {
        .revision =             OMAP24XX_GPIO_REVISION,
        .sysconfig =            OMAP24XX_GPIO_SYSCONFIG,
        .direction =            OMAP24XX_GPIO_OE,
        .datain =               OMAP24XX_GPIO_DATAIN,
        .dataout =              OMAP24XX_GPIO_DATAOUT,
        .set_dataout =          OMAP24XX_GPIO_SETDATAOUT,
        .clr_dataout =          OMAP24XX_GPIO_CLEARDATAOUT,
        .irqstatus =            OMAP24XX_GPIO_IRQSTATUS1,
        .irqstatus2 =           OMAP24XX_GPIO_IRQSTATUS2,
        .irqenable =            OMAP24XX_GPIO_IRQENABLE1,
        .irqenable2 =           OMAP24XX_GPIO_IRQENABLE2,
        .set_irqenable =        OMAP24XX_GPIO_SETIRQENABLE1,
        .clr_irqenable =        OMAP24XX_GPIO_CLEARIRQENABLE1,
        .debounce =             OMAP24XX_GPIO_DEBOUNCE_VAL,
        .debounce_en =          OMAP24XX_GPIO_DEBOUNCE_EN,
        .ctrl =                 OMAP24XX_GPIO_CTRL,
        .wkup_en =              OMAP24XX_GPIO_WAKE_EN,
        .leveldetect0 =         OMAP24XX_GPIO_LEVELDETECT0,
        .leveldetect1 =         OMAP24XX_GPIO_LEVELDETECT1,
        .risingdetect =         OMAP24XX_GPIO_RISINGDETECT,
        .fallingdetect =        OMAP24XX_GPIO_FALLINGDETECT,
};

static const struct omap_gpio_reg_offs omap4_gpio_regs = {
        .revision =             OMAP4_GPIO_REVISION,
        .sysconfig =            OMAP4_GPIO_SYSCONFIG,
        .direction =            OMAP4_GPIO_OE,
        .datain =               OMAP4_GPIO_DATAIN,
        .dataout =              OMAP4_GPIO_DATAOUT,
        .set_dataout =          OMAP4_GPIO_SETDATAOUT,
        .clr_dataout =          OMAP4_GPIO_CLEARDATAOUT,
        .irqstatus =            OMAP4_GPIO_IRQSTATUS0,
        .irqstatus2 =           OMAP4_GPIO_IRQSTATUS1,
        .irqstatus_raw0 =       OMAP4_GPIO_IRQSTATUSRAW0,
        .irqstatus_raw1 =       OMAP4_GPIO_IRQSTATUSRAW1,
        .irqenable =            OMAP4_GPIO_IRQSTATUSSET0,
        .irqenable2 =           OMAP4_GPIO_IRQSTATUSSET1,
        .set_irqenable =        OMAP4_GPIO_IRQSTATUSSET0,
        .clr_irqenable =        OMAP4_GPIO_IRQSTATUSCLR0,
        .debounce =             OMAP4_GPIO_DEBOUNCINGTIME,
        .debounce_en =          OMAP4_GPIO_DEBOUNCENABLE,
        .ctrl =                 OMAP4_GPIO_CTRL,
        .wkup_en =              OMAP4_GPIO_IRQWAKEN0,
        .leveldetect0 =         OMAP4_GPIO_LEVELDETECT0,
        .leveldetect1 =         OMAP4_GPIO_LEVELDETECT1,
        .risingdetect =         OMAP4_GPIO_RISINGDETECT,
        .fallingdetect =        OMAP4_GPIO_FALLINGDETECT,
};

static const struct omap_gpio_platform_data omap2_pdata = {
        .regs = &omap2_gpio_regs,
        .bank_width = 32,
        .dbck_flag = false,
};

static const struct omap_gpio_platform_data omap3_pdata = {
        .regs = &omap2_gpio_regs,
        .bank_width = 32,
        .dbck_flag = true,
};

static const struct omap_gpio_platform_data omap4_pdata = {
        .regs = &omap4_gpio_regs,
        .bank_width = 32,
        .dbck_flag = true,
};

static const struct of_device_id omap_gpio_match[] = {
        {
                .compatible = "ti,omap4-gpio",
                .data = &omap4_pdata,
        },
        {
                .compatible = "ti,omap3-gpio",
                .data = &omap3_pdata,
        },
        {
                .compatible = "ti,omap2-gpio",
                .data = &omap2_pdata,
        },
        { },
};
MODULE_DEVICE_TABLE(of, omap_gpio_match);

static int omap_gpio_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *node = dev->of_node;
        const struct of_device_id *match;
        const struct omap_gpio_platform_data *pdata;
        struct gpio_bank *bank;
        struct irq_chip *irqc;
        int ret;

        match = of_match_device(of_match_ptr(omap_gpio_match), dev);

        pdata = match ? match->data : dev_get_platdata(dev);
        if (!pdata)
                return -EINVAL;

        bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
        if (!bank)
                return -ENOMEM;

        irqc = devm_kzalloc(dev, sizeof(*irqc), GFP_KERNEL);
        if (!irqc)
                return -ENOMEM;

        irqc->irq_startup = omap_gpio_irq_startup,
        irqc->irq_shutdown = omap_gpio_irq_shutdown,
        irqc->irq_ack = dummy_irq_chip.irq_ack,
        irqc->irq_mask = omap_gpio_mask_irq,
        irqc->irq_unmask = omap_gpio_unmask_irq,
        irqc->irq_set_type = omap_gpio_irq_type,
        irqc->irq_set_wake = omap_gpio_wake_enable,
        irqc->irq_bus_lock = omap_gpio_irq_bus_lock,
        irqc->irq_bus_sync_unlock = gpio_irq_bus_sync_unlock,
        irqc->name = dev_name(&pdev->dev);
        irqc->flags = IRQCHIP_MASK_ON_SUSPEND;
        irqc->parent_device = dev;

        bank->irq = platform_get_irq(pdev, 0);
        if (bank->irq <= 0) {
                if (!bank->irq)
                        bank->irq = -ENXIO;
                return dev_err_probe(dev, bank->irq, "can't get irq resource\n");
        }

        bank->chip.parent = dev;
        bank->chip.owner = THIS_MODULE;
        bank->dbck_flag = pdata->dbck_flag;
        bank->stride = pdata->bank_stride;
        bank->width = pdata->bank_width;
        bank->is_mpuio = pdata->is_mpuio;
        bank->non_wakeup_gpios = pdata->non_wakeup_gpios;
        bank->regs = pdata->regs;
#ifdef CONFIG_OF_GPIO
        bank->chip.of_node = of_node_get(node);
#endif

        if (node) {
                if (!of_property_read_bool(node, "ti,gpio-always-on"))
                        bank->loses_context = true;
        } else {
                bank->loses_context = pdata->loses_context;

                if (bank->loses_context)
                        bank->get_context_loss_count =
                                pdata->get_context_loss_count;
        }

        if (bank->regs->set_dataout && bank->regs->clr_dataout)
                bank->set_dataout = omap_set_gpio_dataout_reg;
        else
                bank->set_dataout = omap_set_gpio_dataout_mask;

        raw_spin_lock_init(&bank->lock);
        raw_spin_lock_init(&bank->wa_lock);

        /* Static mapping, never released */
        bank->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(bank->base)) {
                return PTR_ERR(bank->base);
        }

        if (bank->dbck_flag) {
                bank->dbck = devm_clk_get(dev, "dbclk");
                if (IS_ERR(bank->dbck)) {
                        dev_err(dev,
                                "Could not get gpio dbck. Disable debounce\n");
                        bank->dbck_flag = false;
                } else {
                        clk_prepare(bank->dbck);
                }
        }

        platform_set_drvdata(pdev, bank);

        pm_runtime_enable(dev);
        pm_runtime_get_sync(dev);

        if (bank->is_mpuio)
                omap_mpuio_init(bank);

        omap_gpio_mod_init(bank);

        ret = omap_gpio_chip_init(bank, irqc);
        if (ret) {
                pm_runtime_put_sync(dev);
                pm_runtime_disable(dev);
                if (bank->dbck_flag)
                        clk_unprepare(bank->dbck);
                return ret;
        }

        omap_gpio_show_rev(bank);

        bank->nb.notifier_call = gpio_omap_cpu_notifier;
        cpu_pm_register_notifier(&bank->nb);

        pm_runtime_put(dev);

        return 0;
}

static int omap_gpio_remove(struct platform_device *pdev)
{
        struct gpio_bank *bank = platform_get_drvdata(pdev);

        cpu_pm_unregister_notifier(&bank->nb);
        gpiochip_remove(&bank->chip);
        pm_runtime_disable(&pdev->dev);
        if (bank->dbck_flag)
                clk_unprepare(bank->dbck);

        return 0;
}

static int __maybe_unused omap_gpio_runtime_suspend(struct device *dev)
{
        struct gpio_bank *bank = dev_get_drvdata(dev);
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_gpio_idle(bank, true);
        bank->is_suspended = true;
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return 0;
}

static int __maybe_unused omap_gpio_runtime_resume(struct device *dev)
{
        struct gpio_bank *bank = dev_get_drvdata(dev);
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->lock, flags);
        omap_gpio_unidle(bank);
        bank->is_suspended = false;
        raw_spin_unlock_irqrestore(&bank->lock, flags);

        return 0;
}

static int __maybe_unused omap_gpio_suspend(struct device *dev)
{
        struct gpio_bank *bank = dev_get_drvdata(dev);

        if (bank->is_suspended)
                return 0;

        bank->needs_resume = 1;

        return omap_gpio_runtime_suspend(dev);
}

static int __maybe_unused omap_gpio_resume(struct device *dev)
{
        struct gpio_bank *bank = dev_get_drvdata(dev);

        if (!bank->needs_resume)
                return 0;

        bank->needs_resume = 0;

        return omap_gpio_runtime_resume(dev);
}

static const struct dev_pm_ops gpio_pm_ops = {
        SET_RUNTIME_PM_OPS(omap_gpio_runtime_suspend, omap_gpio_runtime_resume,
                                                                        NULL)
        SET_LATE_SYSTEM_SLEEP_PM_OPS(omap_gpio_suspend, omap_gpio_resume)
};

static struct platform_driver omap_gpio_driver = {
        .probe          = omap_gpio_probe,
        .remove         = omap_gpio_remove,
        .driver         = {
                .name   = "omap_gpio",
                .pm     = &gpio_pm_ops,
                .of_match_table = omap_gpio_match,
        },
};

/*
 * gpio driver register needs to be done before
 * machine_init functions access gpio APIs.
 * Hence omap_gpio_drv_reg() is a postcore_initcall.
 */
static int __init omap_gpio_drv_reg(void)
{
        return platform_driver_register(&omap_gpio_driver);
}
postcore_initcall(omap_gpio_drv_reg);

static void __exit omap_gpio_exit(void)
{
        platform_driver_unregister(&omap_gpio_driver);
}
module_exit(omap_gpio_exit);

MODULE_DESCRIPTION("omap gpio driver");
MODULE_ALIAS("platform:gpio-omap");
MODULE_LICENSE("GPL v2");