// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2013 MundoReader S.L.
 * Author: Heiko Stuebner <heiko@sntech.de>
 *
 * Copyright (c) 2021 Rockchip Electronics Co. Ltd.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include "../pinctrl/core.h"
#include "../pinctrl/pinctrl-rockchip.h"

/*
 * Version ID Register
 * Bits [31:24] - Major Version
 * Bits [23:16] - Minor Version
 * Bits [15:0]  - Revision Number
 */
#define GPIO_TYPE_V1            (0)           /* GPIO Version ID reserved */
#define GPIO_TYPE_V2            (0x01000C2B)
#define GPIO_TYPE_V2_1          (0x0101157C)
#define GPIO_TYPE_V2_2          (0x010219C8)

static const struct rockchip_gpio_regs gpio_regs_v1 = {
        .port_dr = 0x00,
        .port_ddr = 0x04,
        .int_en = 0x30,
        .int_mask = 0x34,
        .int_type = 0x38,
        .int_polarity = 0x3c,
        .int_status = 0x40,
        .int_rawstatus = 0x44,
        .debounce = 0x48,
        .port_eoi = 0x4c,
        .ext_port = 0x50,
};

static const struct rockchip_gpio_regs gpio_regs_v2 = {
        .port_dr = 0x00,
        .port_ddr = 0x08,
        .int_en = 0x10,
        .int_mask = 0x18,
        .int_type = 0x20,
        .int_polarity = 0x28,
        .int_bothedge = 0x30,
        .int_status = 0x50,
        .int_rawstatus = 0x58,
        .debounce = 0x38,
        .dbclk_div_en = 0x40,
        .dbclk_div_con = 0x48,
        .port_eoi = 0x60,
        .ext_port = 0x70,
        .version_id = 0x78,
};

static inline void gpio_writel_v2(u32 val, void __iomem *reg)
{
        writel((val & 0xffff) | 0xffff0000, reg);
        writel((val >> 16) | 0xffff0000, reg + 0x4);
}

static inline u32 gpio_readl_v2(void __iomem *reg)
{
        return readl(reg + 0x4) << 16 | readl(reg);
}

static inline void rockchip_gpio_writel(struct rockchip_pin_bank *bank,
                                        u32 value, unsigned int offset)
{
        void __iomem *reg = bank->reg_base + offset;

        if (bank->gpio_type == GPIO_TYPE_V2)
                gpio_writel_v2(value, reg);
        else
                writel(value, reg);
}

static inline u32 rockchip_gpio_readl(struct rockchip_pin_bank *bank,
                                      unsigned int offset)
{
        void __iomem *reg = bank->reg_base + offset;
        u32 value;

        if (bank->gpio_type == GPIO_TYPE_V2)
                value = gpio_readl_v2(reg);
        else
                value = readl(reg);

        return value;
}

static inline void rockchip_gpio_writel_bit(struct rockchip_pin_bank *bank,
                                            u32 bit, u32 value,
                                            unsigned int offset)
{
        void __iomem *reg = bank->reg_base + offset;
        u32 data;

        if (bank->gpio_type == GPIO_TYPE_V2) {
                if (value)
                        data = BIT(bit % 16) | BIT(bit % 16 + 16);
                else
                        data = BIT(bit % 16 + 16);
                writel(data, bit >= 16 ? reg + 0x4 : reg);
        } else {
                data = readl(reg);
                data &= ~BIT(bit);
                if (value)
                        data |= BIT(bit);
                writel(data, reg);
        }
}

static inline u32 rockchip_gpio_readl_bit(struct rockchip_pin_bank *bank,
                                          u32 bit, unsigned int offset)
{
        void __iomem *reg = bank->reg_base + offset;
        u32 data;

        if (bank->gpio_type == GPIO_TYPE_V2) {
                data = readl(bit >= 16 ? reg + 0x4 : reg);
                data >>= bit % 16;
        } else {
                data = readl(reg);
                data >>= bit;
        }

        return data & (0x1);
}

static int rockchip_gpio_get_direction(struct gpio_chip *chip,
                                       unsigned int offset)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
        u32 data;

        data = rockchip_gpio_readl_bit(bank, offset, bank->gpio_regs->port_ddr);
        if (data)
                return GPIO_LINE_DIRECTION_OUT;

        return GPIO_LINE_DIRECTION_IN;
}

static int rockchip_gpio_set_direction(struct gpio_chip *chip,
                                       unsigned int offset, bool input)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
        unsigned long flags;
        u32 data = input ? 0 : 1;

        raw_spin_lock_irqsave(&bank->slock, flags);
        rockchip_gpio_writel_bit(bank, offset, data, bank->gpio_regs->port_ddr);
        raw_spin_unlock_irqrestore(&bank->slock, flags);

        return 0;
}

static int rockchip_gpio_set(struct gpio_chip *gc, unsigned int offset,
                             int value)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
        unsigned long flags;

        raw_spin_lock_irqsave(&bank->slock, flags);
        rockchip_gpio_writel_bit(bank, offset, value, bank->gpio_regs->port_dr);
        raw_spin_unlock_irqrestore(&bank->slock, flags);

        return 0;
}

static int rockchip_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
        u32 data;

        data = readl(bank->reg_base + bank->gpio_regs->ext_port);
        data >>= offset;
        data &= 1;

        return data;
}

static int rockchip_gpio_set_debounce(struct gpio_chip *gc,
                                      unsigned int offset,
                                      unsigned int debounce)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
        const struct rockchip_gpio_regs *reg = bank->gpio_regs;
        unsigned long flags, div_reg, freq, max_debounce;
        bool div_debounce_support;
        unsigned int cur_div_reg;
        u64 div;

        if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) {
                div_debounce_support = true;
                freq = clk_get_rate(bank->db_clk);
                max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq;
                if (debounce > max_debounce)
                        return -EINVAL;

                div = debounce * freq;
                div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1;
        } else {
                div_debounce_support = false;
        }

        raw_spin_lock_irqsave(&bank->slock, flags);

        /* Only the v1 needs to configure div_en and div_con for dbclk */
        if (debounce) {
                if (div_debounce_support) {
                        /* Configure the max debounce from consumers */
                        cur_div_reg = readl(bank->reg_base +
                                            reg->dbclk_div_con);
                        if (cur_div_reg < div_reg)
                                writel(div_reg, bank->reg_base +
                                       reg->dbclk_div_con);
                        rockchip_gpio_writel_bit(bank, offset, 1,
                                                 reg->dbclk_div_en);
                }

                rockchip_gpio_writel_bit(bank, offset, 1, reg->debounce);
        } else {
                if (div_debounce_support)
                        rockchip_gpio_writel_bit(bank, offset, 0,
                                                 reg->dbclk_div_en);

                rockchip_gpio_writel_bit(bank, offset, 0, reg->debounce);
        }

        raw_spin_unlock_irqrestore(&bank->slock, flags);

        /* Enable or disable dbclk at last */
        if (div_debounce_support) {
                if (debounce)
                        clk_prepare_enable(bank->db_clk);
                else
                        clk_disable_unprepare(bank->db_clk);
        }

        return 0;
}

static int rockchip_gpio_direction_input(struct gpio_chip *gc,
                                         unsigned int offset)
{
        return rockchip_gpio_set_direction(gc, offset, true);
}

static int rockchip_gpio_direction_output(struct gpio_chip *gc,
                                          unsigned int offset, int value)
{
        rockchip_gpio_set(gc, offset, value);

        return rockchip_gpio_set_direction(gc, offset, false);
}

/*
 * gpiolib set_config callback function. The setting of the pin
 * mux function as 'gpio output' will be handled by the pinctrl subsystem
 * interface.
 */
static int rockchip_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
                                  unsigned long config)
{
        enum pin_config_param param = pinconf_to_config_param(config);

        switch (param) {
        case PIN_CONFIG_INPUT_DEBOUNCE:
                rockchip_gpio_set_debounce(gc, offset, true);
                /*
                 * Rockchip's gpio could only support up to one period
                 * of the debounce clock(pclk), which is far away from
                 * satisftying the requirement, as pclk is usually near
                 * 100MHz shared by all peripherals. So the fact is it
                 * has crippled debounce capability could only be useful
                 * to prevent any spurious glitches from waking up the system
                 * if the gpio is conguired as wakeup interrupt source. Let's
                 * still return -ENOTSUPP as before, to make sure the caller
                 * of gpiod_set_debounce won't change its behaviour.
                 */
                return -ENOTSUPP;
        default:
                return -ENOTSUPP;
        }
}

/*
 * gpiod_to_irq() callback function. Creates a mapping between a GPIO pin
 * and a virtual IRQ, if not already present.
 */
static int rockchip_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
{
        struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
        unsigned int virq;

        if (!bank->domain)
                return -ENXIO;

        virq = irq_create_mapping(bank->domain, offset);

        return (virq) ? : -ENXIO;
}

static const struct gpio_chip rockchip_gpiolib_chip = {
        .request = gpiochip_generic_request,
        .free = gpiochip_generic_free,
        .set = rockchip_gpio_set,
        .get = rockchip_gpio_get,
        .get_direction  = rockchip_gpio_get_direction,
        .direction_input = rockchip_gpio_direction_input,
        .direction_output = rockchip_gpio_direction_output,
        .set_config = rockchip_gpio_set_config,
        .to_irq = rockchip_gpio_to_irq,
        .owner = THIS_MODULE,
};

static void rockchip_irq_demux(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct rockchip_pin_bank *bank = irq_desc_get_handler_data(desc);
        unsigned long pending;
        unsigned int irq;

        dev_dbg(bank->dev, "got irq for bank %s\n", bank->name);

        chained_irq_enter(chip, desc);

        pending = readl_relaxed(bank->reg_base + bank->gpio_regs->int_status);
        for_each_set_bit(irq, &pending, 32) {
                dev_dbg(bank->dev, "handling irq %d\n", irq);

                /*
                 * Triggering IRQ on both rising and falling edge
                 * needs manual intervention.
                 */
                if (bank->toggle_edge_mode & BIT(irq)) {
                        u32 data, data_old, polarity;
                        unsigned long flags;

                        data = readl_relaxed(bank->reg_base +
                                             bank->gpio_regs->ext_port);
                        do {
                                raw_spin_lock_irqsave(&bank->slock, flags);

                                polarity = readl_relaxed(bank->reg_base +
                                                         bank->gpio_regs->int_polarity);
                                if (data & BIT(irq))
                                        polarity &= ~BIT(irq);
                                else
                                        polarity |= BIT(irq);
                                writel(polarity,
                                       bank->reg_base +
                                       bank->gpio_regs->int_polarity);

                                raw_spin_unlock_irqrestore(&bank->slock, flags);

                                data_old = data;
                                data = readl_relaxed(bank->reg_base +
                                                     bank->gpio_regs->ext_port);
                        } while ((data & BIT(irq)) != (data_old & BIT(irq)));
                }

                generic_handle_domain_irq(bank->domain, irq);
        }

        chained_irq_exit(chip, desc);
}

static int rockchip_irq_set_type(struct irq_data *d, unsigned int type)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct rockchip_pin_bank *bank = gc->private;
        u32 mask = BIT(d->hwirq);
        u32 polarity;
        u32 level;
        u32 data;
        unsigned long flags;
        int ret = 0;

        raw_spin_lock_irqsave(&bank->slock, flags);

        rockchip_gpio_writel_bit(bank, d->hwirq, 0,
                                 bank->gpio_regs->port_ddr);

        raw_spin_unlock_irqrestore(&bank->slock, flags);

        if (type & IRQ_TYPE_EDGE_BOTH)
                irq_set_handler_locked(d, handle_edge_irq);
        else
                irq_set_handler_locked(d, handle_level_irq);

        raw_spin_lock_irqsave(&bank->slock, flags);

        level = rockchip_gpio_readl(bank, bank->gpio_regs->int_type);
        polarity = rockchip_gpio_readl(bank, bank->gpio_regs->int_polarity);

        if (type == IRQ_TYPE_EDGE_BOTH) {
                if (bank->gpio_type == GPIO_TYPE_V2) {
                        rockchip_gpio_writel_bit(bank, d->hwirq, 1,
                                                 bank->gpio_regs->int_bothedge);
                        goto out;
                } else {
                        bank->toggle_edge_mode |= mask;
                        level &= ~mask;

                        /*
                         * Determine gpio state. If 1 next interrupt should be
                         * low otherwise high.
                         */
                        data = readl(bank->reg_base + bank->gpio_regs->ext_port);
                        if (data & mask)
                                polarity &= ~mask;
                        else
                                polarity |= mask;
                }
        } else {
                if (bank->gpio_type == GPIO_TYPE_V2) {
                        rockchip_gpio_writel_bit(bank, d->hwirq, 0,
                                                 bank->gpio_regs->int_bothedge);
                } else {
                        bank->toggle_edge_mode &= ~mask;
                }
                switch (type) {
                case IRQ_TYPE_EDGE_RISING:
                        level |= mask;
                        polarity |= mask;
                        break;
                case IRQ_TYPE_EDGE_FALLING:
                        level |= mask;
                        polarity &= ~mask;
                        break;
                case IRQ_TYPE_LEVEL_HIGH:
                        level &= ~mask;
                        polarity |= mask;
                        break;
                case IRQ_TYPE_LEVEL_LOW:
                        level &= ~mask;
                        polarity &= ~mask;
                        break;
                default:
                        ret = -EINVAL;
                        goto out;
                }
        }

        rockchip_gpio_writel(bank, level, bank->gpio_regs->int_type);
        rockchip_gpio_writel(bank, polarity, bank->gpio_regs->int_polarity);
out:
        raw_spin_unlock_irqrestore(&bank->slock, flags);

        return ret;
}

static int rockchip_irq_reqres(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct rockchip_pin_bank *bank = gc->private;

        return gpiochip_reqres_irq(&bank->gpio_chip, d->hwirq);
}

static void rockchip_irq_relres(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct rockchip_pin_bank *bank = gc->private;

        gpiochip_relres_irq(&bank->gpio_chip, d->hwirq);
}

static void rockchip_irq_suspend(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct rockchip_pin_bank *bank = gc->private;

        bank->saved_masks = irq_reg_readl(gc, bank->gpio_regs->int_mask);
        irq_reg_writel(gc, ~gc->wake_active, bank->gpio_regs->int_mask);
}

static void rockchip_irq_resume(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct rockchip_pin_bank *bank = gc->private;

        irq_reg_writel(gc, bank->saved_masks, bank->gpio_regs->int_mask);
}

static void rockchip_irq_enable(struct irq_data *d)
{
        irq_gc_mask_clr_bit(d);
}

static void rockchip_irq_disable(struct irq_data *d)
{
        irq_gc_mask_set_bit(d);
}

static int rockchip_interrupts_register(struct rockchip_pin_bank *bank)
{
        unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
        struct irq_chip_generic *gc;
        int ret;

        bank->domain = irq_domain_create_linear(dev_fwnode(bank->dev), 32, &irq_generic_chip_ops,
                                                NULL);
        if (!bank->domain) {
                dev_warn(bank->dev, "could not init irq domain for bank %s\n",
                         bank->name);
                return -EINVAL;
        }

        ret = irq_alloc_domain_generic_chips(bank->domain, 32, 1,
                                             "rockchip_gpio_irq",
                                             handle_level_irq,
                                             clr, 0, 0);
        if (ret) {
                dev_err(bank->dev, "could not alloc generic chips for bank %s\n",
                        bank->name);
                irq_domain_remove(bank->domain);
                return -EINVAL;
        }

        gc = irq_get_domain_generic_chip(bank->domain, 0);
        if (bank->gpio_type == GPIO_TYPE_V2) {
                gc->reg_writel = gpio_writel_v2;
                gc->reg_readl = gpio_readl_v2;
        }

        gc->reg_base = bank->reg_base;
        gc->private = bank;
        gc->chip_types[0].regs.mask = bank->gpio_regs->int_mask;
        gc->chip_types[0].regs.ack = bank->gpio_regs->port_eoi;
        gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
        gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
        gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
        gc->chip_types[0].chip.irq_enable = rockchip_irq_enable;
        gc->chip_types[0].chip.irq_disable = rockchip_irq_disable;
        gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
        gc->chip_types[0].chip.irq_suspend = rockchip_irq_suspend;
        gc->chip_types[0].chip.irq_resume = rockchip_irq_resume;
        gc->chip_types[0].chip.irq_set_type = rockchip_irq_set_type;
        gc->chip_types[0].chip.irq_request_resources = rockchip_irq_reqres;
        gc->chip_types[0].chip.irq_release_resources = rockchip_irq_relres;
        gc->wake_enabled = IRQ_MSK(bank->nr_pins);

        /*
         * Linux assumes that all interrupts start out disabled/masked.
         * Our driver only uses the concept of masked and always keeps
         * things enabled, so for us that's all masked and all enabled.
         */
        rockchip_gpio_writel(bank, 0xffffffff, bank->gpio_regs->int_mask);
        rockchip_gpio_writel(bank, 0xffffffff, bank->gpio_regs->port_eoi);
        rockchip_gpio_writel(bank, 0xffffffff, bank->gpio_regs->int_en);
        gc->mask_cache = 0xffffffff;

        irq_set_chained_handler_and_data(bank->irq,
                                         rockchip_irq_demux, bank);

        return 0;
}

static int rockchip_gpiolib_register(struct rockchip_pin_bank *bank)
{
        struct gpio_chip *gc;
        int ret;

        bank->gpio_chip = rockchip_gpiolib_chip;

        gc = &bank->gpio_chip;
        gc->base = bank->pin_base;
        gc->ngpio = bank->nr_pins;
        gc->label = bank->name;
        gc->parent = bank->dev;

        ret = gpiochip_add_data(gc, bank);
        if (ret) {
                dev_err(bank->dev, "failed to add gpiochip %s, %d\n",
                        gc->label, ret);
                return ret;
        }

        /*
         * For DeviceTree-supported systems, the gpio core checks the
         * pinctrl's device node for the "gpio-ranges" property.
         * If it is present, it takes care of adding the pin ranges
         * for the driver. In this case the driver can skip ahead.
         *
         * In order to remain compatible with older, existing DeviceTree
         * files which don't set the "gpio-ranges" property or systems that
         * utilize ACPI the driver has to call gpiochip_add_pin_range().
         */
        if (!of_property_present(bank->of_node, "gpio-ranges")) {
                struct device_node *pctlnp = of_get_parent(bank->of_node);
                struct pinctrl_dev *pctldev = NULL;

                if (!pctlnp)
                        return -ENODATA;

                pctldev = of_pinctrl_get(pctlnp);
                of_node_put(pctlnp);
                if (!pctldev)
                        return -ENODEV;

                ret = gpiochip_add_pin_range(gc, dev_name(pctldev->dev), 0,
                                             gc->base, gc->ngpio);
                if (ret) {
                        dev_err(bank->dev, "Failed to add pin range\n");
                        goto fail;
                }
        }

        ret = rockchip_interrupts_register(bank);
        if (ret) {
                dev_err(bank->dev, "failed to register interrupt, %d\n", ret);
                goto fail;
        }

        return 0;

fail:
        gpiochip_remove(&bank->gpio_chip);

        return ret;
}

static int rockchip_get_bank_data(struct rockchip_pin_bank *bank)
{
        struct resource res;
        int id = 0;

        if (of_address_to_resource(bank->of_node, 0, &res)) {
                dev_err(bank->dev, "cannot find IO resource for bank\n");
                return -ENOENT;
        }

        bank->reg_base = devm_ioremap_resource(bank->dev, &res);
        if (IS_ERR(bank->reg_base))
                return PTR_ERR(bank->reg_base);

        bank->irq = irq_of_parse_and_map(bank->of_node, 0);
        if (!bank->irq)
                return -EINVAL;

        bank->clk = of_clk_get(bank->of_node, 0);
        if (IS_ERR(bank->clk))
                return PTR_ERR(bank->clk);

        clk_prepare_enable(bank->clk);
        id = readl(bank->reg_base + gpio_regs_v2.version_id);

        switch (id) {
        case GPIO_TYPE_V2:
        case GPIO_TYPE_V2_1:
        case GPIO_TYPE_V2_2:
                bank->gpio_regs = &gpio_regs_v2;
                bank->gpio_type = GPIO_TYPE_V2;
                bank->db_clk = of_clk_get(bank->of_node, 1);
                if (IS_ERR(bank->db_clk)) {
                        dev_err(bank->dev, "cannot find debounce clk\n");
                        clk_disable_unprepare(bank->clk);
                        return -EINVAL;
                }
                break;
        case GPIO_TYPE_V1:
                bank->gpio_regs = &gpio_regs_v1;
                bank->gpio_type = GPIO_TYPE_V1;
                break;
        default:
                dev_err(bank->dev, "unsupported version ID: 0x%08x\n", id);
                return -ENODEV;
        }

        return 0;
}

static struct rockchip_pin_bank *
rockchip_gpio_find_bank(struct pinctrl_dev *pctldev, int id)
{
        struct rockchip_pinctrl *info;
        struct rockchip_pin_bank *bank;
        int i, found = 0;

        info = pinctrl_dev_get_drvdata(pctldev);
        bank = info->ctrl->pin_banks;
        for (i = 0; i < info->ctrl->nr_banks; i++, bank++) {
                if (bank->bank_num == id) {
                        found = 1;
                        break;
                }
        }

        return found ? bank : NULL;
}

static int rockchip_gpio_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        struct device_node *pctlnp = of_get_parent(np);
        struct pinctrl_dev *pctldev = NULL;
        struct rockchip_pin_bank *bank = NULL;
        struct rockchip_pin_deferred *cfg;
        static int gpio;
        int id, ret;

        if (!np || !pctlnp)
                return -ENODEV;

        pctldev = of_pinctrl_get(pctlnp);
        of_node_put(pctlnp);
        if (!pctldev)
                return -EPROBE_DEFER;

        id = of_alias_get_id(np, "gpio");
        if (id < 0)
                id = gpio++;

        bank = rockchip_gpio_find_bank(pctldev, id);
        if (!bank)
                return -EINVAL;

        bank->dev = dev;
        bank->of_node = np;

        raw_spin_lock_init(&bank->slock);

        ret = rockchip_get_bank_data(bank);
        if (ret)
                return ret;

        /*
         * Prevent clashes with a deferred output setting
         * being added right at this moment.
         */
        mutex_lock(&bank->deferred_lock);

        ret = rockchip_gpiolib_register(bank);
        if (ret) {
                clk_disable_unprepare(bank->clk);
                mutex_unlock(&bank->deferred_lock);
                return ret;
        }

        while (!list_empty(&bank->deferred_pins)) {
                cfg = list_first_entry(&bank->deferred_pins,
                                       struct rockchip_pin_deferred, head);
                list_del(&cfg->head);

                switch (cfg->param) {
                case PIN_CONFIG_LEVEL:
                        ret = rockchip_gpio_direction_output(&bank->gpio_chip, cfg->pin, cfg->arg);
                        if (ret)
                                dev_warn(dev, "setting output pin %u to %u failed\n", cfg->pin,
                                         cfg->arg);
                        break;
                case PIN_CONFIG_INPUT_ENABLE:
                        ret = rockchip_gpio_direction_input(&bank->gpio_chip, cfg->pin);
                        if (ret)
                                dev_warn(dev, "setting input pin %u failed\n", cfg->pin);
                        break;
                default:
                        dev_warn(dev, "unknown deferred config param %d\n", cfg->param);
                        break;
                }
                kfree(cfg);
        }

        mutex_unlock(&bank->deferred_lock);

        platform_set_drvdata(pdev, bank);
        dev_info(dev, "probed %pOF\n", np);

        return 0;
}

static void rockchip_gpio_remove(struct platform_device *pdev)
{
        struct rockchip_pin_bank *bank = platform_get_drvdata(pdev);

        clk_disable_unprepare(bank->clk);
        gpiochip_remove(&bank->gpio_chip);
}

static const struct of_device_id rockchip_gpio_match[] = {
        { .compatible = "rockchip,gpio-bank", },
        { .compatible = "rockchip,rk3188-gpio-bank0" },
        { },
};

static struct platform_driver rockchip_gpio_driver = {
        .probe          = rockchip_gpio_probe,
        .remove         = rockchip_gpio_remove,
        .driver         = {
                .name   = "rockchip-gpio",
                .of_match_table = rockchip_gpio_match,
        },
};

static int __init rockchip_gpio_init(void)
{
        return platform_driver_register(&rockchip_gpio_driver);
}
postcore_initcall(rockchip_gpio_init);

static void __exit rockchip_gpio_exit(void)
{
        platform_driver_unregister(&rockchip_gpio_driver);
}
module_exit(rockchip_gpio_exit);

MODULE_DESCRIPTION("Rockchip gpio driver");
MODULE_ALIAS("platform:rockchip-gpio");
MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(of, rockchip_gpio_match);