// SPDX-License-Identifier: GPL-2.0-only
/*
 *  PCA953x 4/8/16/24/40 bit I/O ports
 *
 *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
 *  Copyright (C) 2007 Marvell International Ltd.
 *
 *  Derived from drivers/i2c/chips/pca9539.c
 */

#include <linux/acpi.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_data/pca953x.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

#include <asm/unaligned.h>

#define PCA953X_INPUT           0x00
#define PCA953X_OUTPUT          0x01
#define PCA953X_INVERT          0x02
#define PCA953X_DIRECTION       0x03

#define REG_ADDR_MASK           0x3f
#define REG_ADDR_EXT            0x40
#define REG_ADDR_AI             0x80

#define PCA957X_IN              0x00
#define PCA957X_INVRT           0x01
#define PCA957X_BKEN            0x02
#define PCA957X_PUPD            0x03
#define PCA957X_CFG             0x04
#define PCA957X_OUT             0x05
#define PCA957X_MSK             0x06
#define PCA957X_INTS            0x07

#define PCAL953X_OUT_STRENGTH   0x20
#define PCAL953X_IN_LATCH       0x22
#define PCAL953X_PULL_EN        0x23
#define PCAL953X_PULL_SEL       0x24
#define PCAL953X_INT_MASK       0x25
#define PCAL953X_INT_STAT       0x26
#define PCAL953X_OUT_CONF       0x27

#define PCAL6524_INT_EDGE       0x28
#define PCAL6524_INT_CLR        0x2a
#define PCAL6524_IN_STATUS      0x2b
#define PCAL6524_OUT_INDCONF    0x2c
#define PCAL6524_DEBOUNCE       0x2d

#define PCA_GPIO_MASK           0x00FF

#define PCAL_GPIO_MASK          0x1f
#define PCAL_PINCTRL_MASK       0x60

#define PCA_INT                 0x0100
#define PCA_PCAL                0x0200
#define PCA_LATCH_INT           (PCA_PCAL | PCA_INT)
#define PCA953X_TYPE            0x1000
#define PCA957X_TYPE            0x2000
#define PCA_TYPE_MASK           0xF000

#define PCA_CHIP_TYPE(x)        ((x) & PCA_TYPE_MASK)

static const struct i2c_device_id pca953x_id[] = {
        { "pca6416", 16 | PCA953X_TYPE | PCA_INT, },
        { "pca9505", 40 | PCA953X_TYPE | PCA_INT, },
        { "pca9534", 8  | PCA953X_TYPE | PCA_INT, },
        { "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
        { "pca9536", 4  | PCA953X_TYPE, },
        { "pca9537", 4  | PCA953X_TYPE | PCA_INT, },
        { "pca9538", 8  | PCA953X_TYPE | PCA_INT, },
        { "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
        { "pca9554", 8  | PCA953X_TYPE | PCA_INT, },
        { "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
        { "pca9556", 8  | PCA953X_TYPE, },
        { "pca9557", 8  | PCA953X_TYPE, },
        { "pca9574", 8  | PCA957X_TYPE | PCA_INT, },
        { "pca9575", 16 | PCA957X_TYPE | PCA_INT, },
        { "pca9698", 40 | PCA953X_TYPE, },

        { "pcal6416", 16 | PCA953X_TYPE | PCA_LATCH_INT, },
        { "pcal6524", 24 | PCA953X_TYPE | PCA_LATCH_INT, },
        { "pcal9555a", 16 | PCA953X_TYPE | PCA_LATCH_INT, },

        { "max7310", 8  | PCA953X_TYPE, },
        { "max7312", 16 | PCA953X_TYPE | PCA_INT, },
        { "max7313", 16 | PCA953X_TYPE | PCA_INT, },
        { "max7315", 8  | PCA953X_TYPE | PCA_INT, },
        { "max7318", 16 | PCA953X_TYPE | PCA_INT, },
        { "pca6107", 8  | PCA953X_TYPE | PCA_INT, },
        { "tca6408", 8  | PCA953X_TYPE | PCA_INT, },
        { "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
        { "tca6424", 24 | PCA953X_TYPE | PCA_INT, },
        { "tca9539", 16 | PCA953X_TYPE | PCA_INT, },
        { "tca9554", 8  | PCA953X_TYPE | PCA_INT, },
        { "xra1202", 8  | PCA953X_TYPE },
        { }
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);

static const struct acpi_device_id pca953x_acpi_ids[] = {
        { "INT3491", 16 | PCA953X_TYPE | PCA_LATCH_INT, },
        { }
};
MODULE_DEVICE_TABLE(acpi, pca953x_acpi_ids);

#define MAX_BANK 5
#define BANK_SZ 8

#define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)

struct pca953x_reg_config {
        int direction;
        int output;
        int input;
        int invert;
};

static const struct pca953x_reg_config pca953x_regs = {
        .direction = PCA953X_DIRECTION,
        .output = PCA953X_OUTPUT,
        .input = PCA953X_INPUT,
        .invert = PCA953X_INVERT,
};

static const struct pca953x_reg_config pca957x_regs = {
        .direction = PCA957X_CFG,
        .output = PCA957X_OUT,
        .input = PCA957X_IN,
        .invert = PCA957X_INVRT,
};

struct pca953x_chip {
        unsigned gpio_start;
        struct mutex i2c_lock;
        struct regmap *regmap;

#ifdef CONFIG_GPIO_PCA953X_IRQ
        struct mutex irq_lock;
        u8 irq_mask[MAX_BANK];
        u8 irq_stat[MAX_BANK];
        u8 irq_trig_raise[MAX_BANK];
        u8 irq_trig_fall[MAX_BANK];
        struct irq_chip irq_chip;
#endif
        atomic_t wakeup_path;

        struct i2c_client *client;
        struct gpio_chip gpio_chip;
        const char *const *names;
        unsigned long driver_data;
        struct regulator *regulator;

        const struct pca953x_reg_config *regs;
};

static int pca953x_bank_shift(struct pca953x_chip *chip)
{
        return fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
}

#define PCA953x_BANK_INPUT      BIT(0)
#define PCA953x_BANK_OUTPUT     BIT(1)
#define PCA953x_BANK_POLARITY   BIT(2)
#define PCA953x_BANK_CONFIG     BIT(3)

#define PCA957x_BANK_INPUT      BIT(0)
#define PCA957x_BANK_POLARITY   BIT(1)
#define PCA957x_BANK_BUSHOLD    BIT(2)
#define PCA957x_BANK_CONFIG     BIT(4)
#define PCA957x_BANK_OUTPUT     BIT(5)

#define PCAL9xxx_BANK_IN_LATCH  BIT(8 + 2)
#define PCAL9xxx_BANK_PULL_EN   BIT(8 + 3)
#define PCAL9xxx_BANK_PULL_SEL  BIT(8 + 4)
#define PCAL9xxx_BANK_IRQ_MASK  BIT(8 + 5)
#define PCAL9xxx_BANK_IRQ_STAT  BIT(8 + 6)

/*
 * We care about the following registers:
 * - Standard set, below 0x40, each port can be replicated up to 8 times
 *   - PCA953x standard
 *     Input port                       0x00 + 0 * bank_size    R
 *     Output port                      0x00 + 1 * bank_size    RW
 *     Polarity Inversion port          0x00 + 2 * bank_size    RW
 *     Configuration port               0x00 + 3 * bank_size    RW
 *   - PCA957x with mixed up registers
 *     Input port                       0x00 + 0 * bank_size    R
 *     Polarity Inversion port          0x00 + 1 * bank_size    RW
 *     Bus hold port                    0x00 + 2 * bank_size    RW
 *     Configuration port               0x00 + 4 * bank_size    RW
 *     Output port                      0x00 + 5 * bank_size    RW
 *
 * - Extended set, above 0x40, often chip specific.
 *   - PCAL6524/PCAL9555A with custom PCAL IRQ handling:
 *     Input latch register             0x40 + 2 * bank_size    RW
 *     Pull-up/pull-down enable reg     0x40 + 3 * bank_size    RW
 *     Pull-up/pull-down select reg     0x40 + 4 * bank_size    RW
 *     Interrupt mask register          0x40 + 5 * bank_size    RW
 *     Interrupt status register        0x40 + 6 * bank_size    R
 *
 * - Registers with bit 0x80 set, the AI bit
 *   The bit is cleared and the registers fall into one of the
 *   categories above.
 */

static bool pca953x_check_register(struct pca953x_chip *chip, unsigned int reg,
                                   u32 checkbank)
{
        int bank_shift = pca953x_bank_shift(chip);
        int bank = (reg & REG_ADDR_MASK) >> bank_shift;
        int offset = reg & (BIT(bank_shift) - 1);

        /* Special PCAL extended register check. */
        if (reg & REG_ADDR_EXT) {
                if (!(chip->driver_data & PCA_PCAL))
                        return false;
                bank += 8;
        }

        /* Register is not in the matching bank. */
        if (!(BIT(bank) & checkbank))
                return false;

        /* Register is not within allowed range of bank. */
        if (offset >= NBANK(chip))
                return false;

        return true;
}

static bool pca953x_readable_register(struct device *dev, unsigned int reg)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);
        u32 bank;

        if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
                bank = PCA953x_BANK_INPUT | PCA953x_BANK_OUTPUT |
                       PCA953x_BANK_POLARITY | PCA953x_BANK_CONFIG;
        } else {
                bank = PCA957x_BANK_INPUT | PCA957x_BANK_OUTPUT |
                       PCA957x_BANK_POLARITY | PCA957x_BANK_CONFIG |
                       PCA957x_BANK_BUSHOLD;
        }

        if (chip->driver_data & PCA_PCAL) {
                bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
                        PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK |
                        PCAL9xxx_BANK_IRQ_STAT;
        }

        return pca953x_check_register(chip, reg, bank);
}

static bool pca953x_writeable_register(struct device *dev, unsigned int reg)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);
        u32 bank;

        if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
                bank = PCA953x_BANK_OUTPUT | PCA953x_BANK_POLARITY |
                        PCA953x_BANK_CONFIG;
        } else {
                bank = PCA957x_BANK_OUTPUT | PCA957x_BANK_POLARITY |
                        PCA957x_BANK_CONFIG | PCA957x_BANK_BUSHOLD;
        }

        if (chip->driver_data & PCA_PCAL)
                bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
                        PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK;

        return pca953x_check_register(chip, reg, bank);
}

static bool pca953x_volatile_register(struct device *dev, unsigned int reg)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);
        u32 bank;

        if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
                bank = PCA953x_BANK_INPUT;
        else
                bank = PCA957x_BANK_INPUT;

        if (chip->driver_data & PCA_PCAL)
                bank |= PCAL9xxx_BANK_IRQ_STAT;

        return pca953x_check_register(chip, reg, bank);
}

static const struct regmap_config pca953x_i2c_regmap = {
        .reg_bits = 8,
        .val_bits = 8,

        .readable_reg = pca953x_readable_register,
        .writeable_reg = pca953x_writeable_register,
        .volatile_reg = pca953x_volatile_register,

        .cache_type = REGCACHE_RBTREE,
        /* REVISIT: should be 0x7f but some 24 bit chips use REG_ADDR_AI */
        .max_register = 0xff,
};

static u8 pca953x_recalc_addr(struct pca953x_chip *chip, int reg, int off,
                              bool write, bool addrinc)
{
        int bank_shift = pca953x_bank_shift(chip);
        int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
        int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
        u8 regaddr = pinctrl | addr | (off / BANK_SZ);

        /* Single byte read doesn't need AI bit set. */
        if (!addrinc)
                return regaddr;

        /* Chips with 24 and more GPIOs always support Auto Increment */
        if (write && NBANK(chip) > 2)
                regaddr |= REG_ADDR_AI;

        /* PCA9575 needs address-increment on multi-byte writes */
        if (PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE)
                regaddr |= REG_ADDR_AI;

        return regaddr;
}

static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
{
        u8 regaddr = pca953x_recalc_addr(chip, reg, 0, true, true);
        int ret;

        ret = regmap_bulk_write(chip->regmap, regaddr, val, NBANK(chip));
        if (ret < 0) {
                dev_err(&chip->client->dev, "failed writing register\n");
                return ret;
        }

        return 0;
}

static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
{
        u8 regaddr = pca953x_recalc_addr(chip, reg, 0, false, true);
        int ret;

        ret = regmap_bulk_read(chip->regmap, regaddr, val, NBANK(chip));
        if (ret < 0) {
                dev_err(&chip->client->dev, "failed reading register\n");
                return ret;
        }

        return 0;
}

static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
                                        true, false);
        u8 bit = BIT(off % BANK_SZ);
        int ret;

        mutex_lock(&chip->i2c_lock);
        ret = regmap_write_bits(chip->regmap, dirreg, bit, bit);
        mutex_unlock(&chip->i2c_lock);
        return ret;
}

static int pca953x_gpio_direction_output(struct gpio_chip *gc,
                unsigned off, int val)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
                                        true, false);
        u8 outreg = pca953x_recalc_addr(chip, chip->regs->output, off,
                                        true, false);
        u8 bit = BIT(off % BANK_SZ);
        int ret;

        mutex_lock(&chip->i2c_lock);
        /* set output level */
        ret = regmap_write_bits(chip->regmap, outreg, bit, val ? bit : 0);
        if (ret)
                goto exit;

        /* then direction */
        ret = regmap_write_bits(chip->regmap, dirreg, bit, 0);
exit:
        mutex_unlock(&chip->i2c_lock);
        return ret;
}

static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 inreg = pca953x_recalc_addr(chip, chip->regs->input, off,
                                       true, false);
        u8 bit = BIT(off % BANK_SZ);
        u32 reg_val;
        int ret;

        mutex_lock(&chip->i2c_lock);
        ret = regmap_read(chip->regmap, inreg, &reg_val);
        mutex_unlock(&chip->i2c_lock);
        if (ret < 0) {
                /* NOTE:  diagnostic already emitted; that's all we should
                 * do unless gpio_*_value_cansleep() calls become different
                 * from their nonsleeping siblings (and report faults).
                 */
                return 0;
        }

        return !!(reg_val & bit);
}

static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 outreg = pca953x_recalc_addr(chip, chip->regs->output, off,
                                        true, false);
        u8 bit = BIT(off % BANK_SZ);

        mutex_lock(&chip->i2c_lock);
        regmap_write_bits(chip->regmap, outreg, bit, val ? bit : 0);
        mutex_unlock(&chip->i2c_lock);
}

static int pca953x_gpio_get_direction(struct gpio_chip *gc, unsigned off)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
                                        true, false);
        u8 bit = BIT(off % BANK_SZ);
        u32 reg_val;
        int ret;

        mutex_lock(&chip->i2c_lock);
        ret = regmap_read(chip->regmap, dirreg, &reg_val);
        mutex_unlock(&chip->i2c_lock);
        if (ret < 0)
                return ret;

        return !!(reg_val & bit);
}

static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
                                      unsigned long *mask, unsigned long *bits)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        unsigned int bank_mask, bank_val;
        int bank;
        u8 reg_val[MAX_BANK];
        int ret;

        mutex_lock(&chip->i2c_lock);
        ret = pca953x_read_regs(chip, chip->regs->output, reg_val);
        if (ret)
                goto exit;

        for (bank = 0; bank < NBANK(chip); bank++) {
                bank_mask = mask[bank / sizeof(*mask)] >>
                           ((bank % sizeof(*mask)) * 8);
                if (bank_mask) {
                        bank_val = bits[bank / sizeof(*bits)] >>
                                  ((bank % sizeof(*bits)) * 8);
                        bank_val &= bank_mask;
                        reg_val[bank] = (reg_val[bank] & ~bank_mask) | bank_val;
                }
        }

        pca953x_write_regs(chip, chip->regs->output, reg_val);
exit:
        mutex_unlock(&chip->i2c_lock);
}

static int pca953x_gpio_set_pull_up_down(struct pca953x_chip *chip,
                                         unsigned int offset,
                                         unsigned long config)
{
        u8 pull_en_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_EN, offset,
                                             true, false);
        u8 pull_sel_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_SEL, offset,
                                              true, false);
        u8 bit = BIT(offset % BANK_SZ);
        int ret;

        /*
         * pull-up/pull-down configuration requires PCAL extended
         * registers
         */
        if (!(chip->driver_data & PCA_PCAL))
                return -ENOTSUPP;

        mutex_lock(&chip->i2c_lock);

        /* Disable pull-up/pull-down */
        ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, 0);
        if (ret)
                goto exit;

        /* Configure pull-up/pull-down */
        if (config == PIN_CONFIG_BIAS_PULL_UP)
                ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, bit);
        else if (config == PIN_CONFIG_BIAS_PULL_DOWN)
                ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, 0);
        if (ret)
                goto exit;

        /* Enable pull-up/pull-down */
        ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, bit);

exit:
        mutex_unlock(&chip->i2c_lock);
        return ret;
}

static int pca953x_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
                                   unsigned long config)
{
        struct pca953x_chip *chip = gpiochip_get_data(gc);

        switch (config) {
        case PIN_CONFIG_BIAS_PULL_UP:
        case PIN_CONFIG_BIAS_PULL_DOWN:
                return pca953x_gpio_set_pull_up_down(chip, offset, config);
        default:
                return -ENOTSUPP;
        }
}

static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
        struct gpio_chip *gc;

        gc = &chip->gpio_chip;

        gc->direction_input  = pca953x_gpio_direction_input;
        gc->direction_output = pca953x_gpio_direction_output;
        gc->get = pca953x_gpio_get_value;
        gc->set = pca953x_gpio_set_value;
        gc->get_direction = pca953x_gpio_get_direction;
        gc->set_multiple = pca953x_gpio_set_multiple;
        gc->set_config = pca953x_gpio_set_config;
        gc->can_sleep = true;

        gc->base = chip->gpio_start;
        gc->ngpio = gpios;
        gc->label = dev_name(&chip->client->dev);
        gc->parent = &chip->client->dev;
        gc->owner = THIS_MODULE;
        gc->names = chip->names;
}

#ifdef CONFIG_GPIO_PCA953X_IRQ
static void pca953x_irq_mask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);

        chip->irq_mask[d->hwirq / BANK_SZ] &= ~(1 << (d->hwirq % BANK_SZ));
}

static void pca953x_irq_unmask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);

        chip->irq_mask[d->hwirq / BANK_SZ] |= 1 << (d->hwirq % BANK_SZ);
}

static int pca953x_irq_set_wake(struct irq_data *d, unsigned int on)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);

        if (on)
                atomic_inc(&chip->wakeup_path);
        else
                atomic_dec(&chip->wakeup_path);

        return irq_set_irq_wake(chip->client->irq, on);
}

static void pca953x_irq_bus_lock(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);

        mutex_lock(&chip->irq_lock);
}

static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 new_irqs;
        int level, i;
        u8 invert_irq_mask[MAX_BANK];
        u8 reg_direction[MAX_BANK];

        pca953x_read_regs(chip, chip->regs->direction, reg_direction);

        if (chip->driver_data & PCA_PCAL) {
                /* Enable latch on interrupt-enabled inputs */
                pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask);

                for (i = 0; i < NBANK(chip); i++)
                        invert_irq_mask[i] = ~chip->irq_mask[i];

                /* Unmask enabled interrupts */
                pca953x_write_regs(chip, PCAL953X_INT_MASK, invert_irq_mask);
        }

        /* Look for any newly setup interrupt */
        for (i = 0; i < NBANK(chip); i++) {
                new_irqs = chip->irq_trig_fall[i] | chip->irq_trig_raise[i];
                new_irqs &= reg_direction[i];

                while (new_irqs) {
                        level = __ffs(new_irqs);
                        pca953x_gpio_direction_input(&chip->gpio_chip,
                                                        level + (BANK_SZ * i));
                        new_irqs &= ~(1 << level);
                }
        }

        mutex_unlock(&chip->irq_lock);
}

static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        int bank_nb = d->hwirq / BANK_SZ;
        u8 mask = 1 << (d->hwirq % BANK_SZ);

        if (!(type & IRQ_TYPE_EDGE_BOTH)) {
                dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
                        d->irq, type);
                return -EINVAL;
        }

        if (type & IRQ_TYPE_EDGE_FALLING)
                chip->irq_trig_fall[bank_nb] |= mask;
        else
                chip->irq_trig_fall[bank_nb] &= ~mask;

        if (type & IRQ_TYPE_EDGE_RISING)
                chip->irq_trig_raise[bank_nb] |= mask;
        else
                chip->irq_trig_raise[bank_nb] &= ~mask;

        return 0;
}

static void pca953x_irq_shutdown(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct pca953x_chip *chip = gpiochip_get_data(gc);
        u8 mask = 1 << (d->hwirq % BANK_SZ);

        chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
        chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
}

static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
{
        u8 cur_stat[MAX_BANK];
        u8 old_stat[MAX_BANK];
        bool pending_seen = false;
        bool trigger_seen = false;
        u8 trigger[MAX_BANK];
        u8 reg_direction[MAX_BANK];
        int ret, i;

        if (chip->driver_data & PCA_PCAL) {
                /* Read the current interrupt status from the device */
                ret = pca953x_read_regs(chip, PCAL953X_INT_STAT, trigger);
                if (ret)
                        return false;

                /* Check latched inputs and clear interrupt status */
                ret = pca953x_read_regs(chip, PCA953X_INPUT, cur_stat);
                if (ret)
                        return false;

                for (i = 0; i < NBANK(chip); i++) {
                        /* Apply filter for rising/falling edge selection */
                        pending[i] = (~cur_stat[i] & chip->irq_trig_fall[i]) |
                                (cur_stat[i] & chip->irq_trig_raise[i]);
                        pending[i] &= trigger[i];
                        if (pending[i])
                                pending_seen = true;
                }

                return pending_seen;
        }

        ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
        if (ret)
                return false;

        /* Remove output pins from the equation */
        pca953x_read_regs(chip, chip->regs->direction, reg_direction);
        for (i = 0; i < NBANK(chip); i++)
                cur_stat[i] &= reg_direction[i];

        memcpy(old_stat, chip->irq_stat, NBANK(chip));

        for (i = 0; i < NBANK(chip); i++) {
                trigger[i] = (cur_stat[i] ^ old_stat[i]) & chip->irq_mask[i];
                if (trigger[i])
                        trigger_seen = true;
        }

        if (!trigger_seen)
                return false;

        memcpy(chip->irq_stat, cur_stat, NBANK(chip));

        for (i = 0; i < NBANK(chip); i++) {
                pending[i] = (old_stat[i] & chip->irq_trig_fall[i]) |
                        (cur_stat[i] & chip->irq_trig_raise[i]);
                pending[i] &= trigger[i];
                if (pending[i])
                        pending_seen = true;
        }

        return pending_seen;
}

static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
        struct pca953x_chip *chip = devid;
        u8 pending[MAX_BANK];
        u8 level;
        unsigned nhandled = 0;
        int i;

        if (!pca953x_irq_pending(chip, pending))
                return IRQ_NONE;

        for (i = 0; i < NBANK(chip); i++) {
                while (pending[i]) {
                        level = __ffs(pending[i]);
                        handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
                                                        level + (BANK_SZ * i)));
                        pending[i] &= ~(1 << level);
                        nhandled++;
                }
        }

        return (nhandled > 0) ? IRQ_HANDLED : IRQ_NONE;
}

static int pca953x_irq_setup(struct pca953x_chip *chip,
                             int irq_base)
{
        struct i2c_client *client = chip->client;
        struct irq_chip *irq_chip = &chip->irq_chip;
        u8 reg_direction[MAX_BANK];
        int ret, i;

        if (!client->irq)
                return 0;

        if (irq_base == -1)
                return 0;

        if (!(chip->driver_data & PCA_INT))
                return 0;

        ret = pca953x_read_regs(chip, chip->regs->input, chip->irq_stat);
        if (ret)
                return ret;

        /*
         * There is no way to know which GPIO line generated the
         * interrupt.  We have to rely on the previous read for
         * this purpose.
         */
        pca953x_read_regs(chip, chip->regs->direction, reg_direction);
        for (i = 0; i < NBANK(chip); i++)
                chip->irq_stat[i] &= reg_direction[i];
        mutex_init(&chip->irq_lock);

        ret = devm_request_threaded_irq(&client->dev, client->irq,
                                        NULL, pca953x_irq_handler,
                                        IRQF_TRIGGER_LOW | IRQF_ONESHOT |
                                        IRQF_SHARED,
                                        dev_name(&client->dev), chip);
        if (ret) {
                dev_err(&client->dev, "failed to request irq %d\n",
                        client->irq);
                return ret;
        }

        irq_chip->name = dev_name(&chip->client->dev);
        irq_chip->irq_mask = pca953x_irq_mask;
        irq_chip->irq_unmask = pca953x_irq_unmask;
        irq_chip->irq_set_wake = pca953x_irq_set_wake;
        irq_chip->irq_bus_lock = pca953x_irq_bus_lock;
        irq_chip->irq_bus_sync_unlock = pca953x_irq_bus_sync_unlock;
        irq_chip->irq_set_type = pca953x_irq_set_type;
        irq_chip->irq_shutdown = pca953x_irq_shutdown;

        ret =  gpiochip_irqchip_add_nested(&chip->gpio_chip, irq_chip,
                                           irq_base, handle_simple_irq,
                                           IRQ_TYPE_NONE);
        if (ret) {
                dev_err(&client->dev,
                        "could not connect irqchip to gpiochip\n");
                return ret;
        }

        gpiochip_set_nested_irqchip(&chip->gpio_chip, irq_chip, client->irq);

        return 0;
}

#else /* CONFIG_GPIO_PCA953X_IRQ */
static int pca953x_irq_setup(struct pca953x_chip *chip,
                             int irq_base)
{
        struct i2c_client *client = chip->client;

        if (client->irq && irq_base != -1 && (chip->driver_data & PCA_INT))
                dev_warn(&client->dev, "interrupt support not compiled in\n");

        return 0;
}
#endif

static int device_pca95xx_init(struct pca953x_chip *chip, u32 invert)
{
        int ret;
        u8 val[MAX_BANK];

        ret = regcache_sync_region(chip->regmap, chip->regs->output,
                                   chip->regs->output + NBANK(chip));
        if (ret != 0)
                goto out;

        ret = regcache_sync_region(chip->regmap, chip->regs->direction,
                                   chip->regs->direction + NBANK(chip));
        if (ret != 0)
                goto out;

        /* set platform specific polarity inversion */
        if (invert)
                memset(val, 0xFF, NBANK(chip));
        else
                memset(val, 0, NBANK(chip));

        ret = pca953x_write_regs(chip, chip->regs->invert, val);
out:
        return ret;
}

static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
{
        int ret;
        u8 val[MAX_BANK];

        ret = device_pca95xx_init(chip, invert);
        if (ret)
                goto out;

        /* To enable register 6, 7 to control pull up and pull down */
        memset(val, 0x02, NBANK(chip));
        ret = pca953x_write_regs(chip, PCA957X_BKEN, val);
        if (ret)
                goto out;

        return 0;
out:
        return ret;
}

static const struct of_device_id pca953x_dt_ids[];

static int pca953x_probe(struct i2c_client *client,
                                   const struct i2c_device_id *i2c_id)
{
        struct pca953x_platform_data *pdata;
        struct pca953x_chip *chip;
        int irq_base = 0;
        int ret;
        u32 invert = 0;
        struct regulator *reg;

        chip = devm_kzalloc(&client->dev,
                        sizeof(struct pca953x_chip), GFP_KERNEL);
        if (chip == NULL)
                return -ENOMEM;

        pdata = dev_get_platdata(&client->dev);
        if (pdata) {
                irq_base = pdata->irq_base;
                chip->gpio_start = pdata->gpio_base;
                invert = pdata->invert;
                chip->names = pdata->names;
        } else {
                struct gpio_desc *reset_gpio;

                chip->gpio_start = -1;
                irq_base = 0;

                /*
                 * See if we need to de-assert a reset pin.
                 *
                 * There is no known ACPI-enabled platforms that are
                 * using "reset" GPIO. Otherwise any of those platform
                 * must use _DSD method with corresponding property.
                 */
                reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
                                                     GPIOD_OUT_LOW);
                if (IS_ERR(reset_gpio))
                        return PTR_ERR(reset_gpio);
        }

        chip->client = client;

        reg = devm_regulator_get(&client->dev, "vcc");
        if (IS_ERR(reg)) {
                ret = PTR_ERR(reg);
                if (ret != -EPROBE_DEFER)
                        dev_err(&client->dev, "reg get err: %d\n", ret);
                return ret;
        }
        ret = regulator_enable(reg);
        if (ret) {
                dev_err(&client->dev, "reg en err: %d\n", ret);
                return ret;
        }
        chip->regulator = reg;

        if (i2c_id) {
                chip->driver_data = i2c_id->driver_data;
        } else {
                const struct acpi_device_id *acpi_id;
                struct device *dev = &client->dev;

                chip->driver_data = (uintptr_t)of_device_get_match_data(dev);
                if (!chip->driver_data) {
                        acpi_id = acpi_match_device(pca953x_acpi_ids, dev);
                        if (!acpi_id) {
                                ret = -ENODEV;
                                goto err_exit;
                        }

                        chip->driver_data = acpi_id->driver_data;
                }
        }

        i2c_set_clientdata(client, chip);

        chip->regmap = devm_regmap_init_i2c(client, &pca953x_i2c_regmap);
        if (IS_ERR(chip->regmap)) {
                ret = PTR_ERR(chip->regmap);
                goto err_exit;
        }

        regcache_mark_dirty(chip->regmap);

        mutex_init(&chip->i2c_lock);
        /*
         * In case we have an i2c-mux controlled by a GPIO provided by an
         * expander using the same driver higher on the device tree, read the
         * i2c adapter nesting depth and use the retrieved value as lockdep
         * subclass for chip->i2c_lock.
         *
         * REVISIT: This solution is not complete. It protects us from lockdep
         * false positives when the expander controlling the i2c-mux is on
         * a different level on the device tree, but not when it's on the same
         * level on a different branch (in which case the subclass number
         * would be the same).
         *
         * TODO: Once a correct solution is developed, a similar fix should be
         * applied to all other i2c-controlled GPIO expanders (and potentially
         * regmap-i2c).
         */
        lockdep_set_subclass(&chip->i2c_lock,
                             i2c_adapter_depth(client->adapter));

        /* initialize cached registers from their original values.
         * we can't share this chip with another i2c master.
         */
        pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);

        if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
                chip->regs = &pca953x_regs;

                ret = device_pca95xx_init(chip, invert);
        } else {
                chip->regs = &pca957x_regs;
                ret = device_pca957x_init(chip, invert);
        }
        if (ret)
                goto err_exit;

        ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
        if (ret)
                goto err_exit;

        ret = pca953x_irq_setup(chip, irq_base);
        if (ret)
                goto err_exit;

        if (pdata && pdata->setup) {
                ret = pdata->setup(client, chip->gpio_chip.base,
                                chip->gpio_chip.ngpio, pdata->context);
                if (ret < 0)
                        dev_warn(&client->dev, "setup failed, %d\n", ret);
        }

        return 0;

err_exit:
        regulator_disable(chip->regulator);
        return ret;
}

static int pca953x_remove(struct i2c_client *client)
{
        struct pca953x_platform_data *pdata = dev_get_platdata(&client->dev);
        struct pca953x_chip *chip = i2c_get_clientdata(client);
        int ret;

        if (pdata && pdata->teardown) {
                ret = pdata->teardown(client, chip->gpio_chip.base,
                                chip->gpio_chip.ngpio, pdata->context);
                if (ret < 0)
                        dev_err(&client->dev, "%s failed, %d\n",
                                        "teardown", ret);
        } else {
                ret = 0;
        }

        regulator_disable(chip->regulator);

        return ret;
}

#ifdef CONFIG_PM_SLEEP
static int pca953x_regcache_sync(struct device *dev)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);
        int ret;

        /*
         * The ordering between direction and output is important,
         * sync these registers first and only then sync the rest.
         */
        ret = regcache_sync_region(chip->regmap, chip->regs->direction,
                                   chip->regs->direction + NBANK(chip));
        if (ret != 0) {
                dev_err(dev, "Failed to sync GPIO dir registers: %d\n", ret);
                return ret;
        }

        ret = regcache_sync_region(chip->regmap, chip->regs->output,
                                   chip->regs->output + NBANK(chip));
        if (ret != 0) {
                dev_err(dev, "Failed to sync GPIO out registers: %d\n", ret);
                return ret;
        }

#ifdef CONFIG_GPIO_PCA953X_IRQ
        if (chip->driver_data & PCA_PCAL) {
                ret = regcache_sync_region(chip->regmap, PCAL953X_IN_LATCH,
                                           PCAL953X_IN_LATCH + NBANK(chip));
                if (ret != 0) {
                        dev_err(dev, "Failed to sync INT latch registers: %d\n",
                                ret);
                        return ret;
                }

                ret = regcache_sync_region(chip->regmap, PCAL953X_INT_MASK,
                                           PCAL953X_INT_MASK + NBANK(chip));
                if (ret != 0) {
                        dev_err(dev, "Failed to sync INT mask registers: %d\n",
                                ret);
                        return ret;
                }
        }
#endif

        return 0;
}

static int pca953x_suspend(struct device *dev)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);

        regcache_cache_only(chip->regmap, true);

        if (atomic_read(&chip->wakeup_path))
                device_set_wakeup_path(dev);
        else
                regulator_disable(chip->regulator);

        return 0;
}

static int pca953x_resume(struct device *dev)
{
        struct pca953x_chip *chip = dev_get_drvdata(dev);
        int ret;

        if (!atomic_read(&chip->wakeup_path)) {
                ret = regulator_enable(chip->regulator);
                if (ret != 0) {
                        dev_err(dev, "Failed to enable regulator: %d\n", ret);
                        return 0;
                }
        }

        regcache_cache_only(chip->regmap, false);
        regcache_mark_dirty(chip->regmap);
        ret = pca953x_regcache_sync(dev);
        if (ret)
                return ret;

        ret = regcache_sync(chip->regmap);
        if (ret != 0) {
                dev_err(dev, "Failed to restore register map: %d\n", ret);
                return ret;
        }

        return 0;
}
#endif

/* convenience to stop overlong match-table lines */
#define OF_953X(__nrgpio, __int) (void *)(__nrgpio | PCA953X_TYPE | __int)
#define OF_957X(__nrgpio, __int) (void *)(__nrgpio | PCA957X_TYPE | __int)

static const struct of_device_id pca953x_dt_ids[] = {
        { .compatible = "nxp,pca6416", .data = OF_953X(16, PCA_INT), },
        { .compatible = "nxp,pca9505", .data = OF_953X(40, PCA_INT), },
        { .compatible = "nxp,pca9534", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "nxp,pca9535", .data = OF_953X(16, PCA_INT), },
        { .compatible = "nxp,pca9536", .data = OF_953X( 4, 0), },
        { .compatible = "nxp,pca9537", .data = OF_953X( 4, PCA_INT), },
        { .compatible = "nxp,pca9538", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "nxp,pca9539", .data = OF_953X(16, PCA_INT), },
        { .compatible = "nxp,pca9554", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "nxp,pca9555", .data = OF_953X(16, PCA_INT), },
        { .compatible = "nxp,pca9556", .data = OF_953X( 8, 0), },
        { .compatible = "nxp,pca9557", .data = OF_953X( 8, 0), },
        { .compatible = "nxp,pca9574", .data = OF_957X( 8, PCA_INT), },
        { .compatible = "nxp,pca9575", .data = OF_957X(16, PCA_INT), },
        { .compatible = "nxp,pca9698", .data = OF_953X(40, 0), },

        { .compatible = "nxp,pcal6416", .data = OF_953X(16, PCA_LATCH_INT), },
        { .compatible = "nxp,pcal6524", .data = OF_953X(24, PCA_LATCH_INT), },
        { .compatible = "nxp,pcal9555a", .data = OF_953X(16, PCA_LATCH_INT), },

        { .compatible = "maxim,max7310", .data = OF_953X( 8, 0), },
        { .compatible = "maxim,max7312", .data = OF_953X(16, PCA_INT), },
        { .compatible = "maxim,max7313", .data = OF_953X(16, PCA_INT), },
        { .compatible = "maxim,max7315", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "maxim,max7318", .data = OF_953X(16, PCA_INT), },

        { .compatible = "ti,pca6107", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "ti,pca9536", .data = OF_953X( 4, 0), },
        { .compatible = "ti,tca6408", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "ti,tca6416", .data = OF_953X(16, PCA_INT), },
        { .compatible = "ti,tca6424", .data = OF_953X(24, PCA_INT), },
        { .compatible = "ti,tca9539", .data = OF_953X(16, PCA_INT), },

        { .compatible = "onnn,cat9554", .data = OF_953X( 8, PCA_INT), },
        { .compatible = "onnn,pca9654", .data = OF_953X( 8, PCA_INT), },

        { .compatible = "exar,xra1202", .data = OF_953X( 8, 0), },
        { }
};

MODULE_DEVICE_TABLE(of, pca953x_dt_ids);

static SIMPLE_DEV_PM_OPS(pca953x_pm_ops, pca953x_suspend, pca953x_resume);

static struct i2c_driver pca953x_driver = {
        .driver = {
                .name   = "pca953x",
                .pm     = &pca953x_pm_ops,
                .of_match_table = pca953x_dt_ids,
                .acpi_match_table = ACPI_PTR(pca953x_acpi_ids),
        },
        .probe          = pca953x_probe,
        .remove         = pca953x_remove,
        .id_table       = pca953x_id,
};

static int __init pca953x_init(void)
{
        return i2c_add_driver(&pca953x_driver);
}
/* register after i2c postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(pca953x_init);

static void __exit pca953x_exit(void)
{
        i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);

MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");