/*
 * Copyright (c) 2009-2011 Samsung Electronics Co., Ltd.
 *              http://www.samsung.com/
 *
 * Copyright 2008 Openmoko, Inc.
 * Copyright 2008 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * SAMSUNG - GPIOlib support
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/of_address.h>

#include <asm/irq.h>

#include <mach/irqs.h>
#include <mach/map.h>
#include <mach/regs-gpio.h>
#include <mach/gpio-samsung.h>

#include <plat/cpu.h>
#include <plat/gpio-core.h>
#include <plat/gpio-cfg.h>
#include <plat/gpio-cfg-helpers.h>
#include <plat/pm.h>

int samsung_gpio_setpull_updown(struct samsung_gpio_chip *chip,
                                unsigned int off, samsung_gpio_pull_t pull)
{
        void __iomem *reg = chip->base + 0x08;
        int shift = off * 2;
        u32 pup;

        pup = __raw_readl(reg);
        pup &= ~(3 << shift);
        pup |= pull << shift;
        __raw_writel(pup, reg);

        return 0;
}

samsung_gpio_pull_t samsung_gpio_getpull_updown(struct samsung_gpio_chip *chip,
                                                unsigned int off)
{
        void __iomem *reg = chip->base + 0x08;
        int shift = off * 2;
        u32 pup = __raw_readl(reg);

        pup >>= shift;
        pup &= 0x3;

        return (__force samsung_gpio_pull_t)pup;
}

int s3c2443_gpio_setpull(struct samsung_gpio_chip *chip,
                         unsigned int off, samsung_gpio_pull_t pull)
{
        switch (pull) {
        case S3C_GPIO_PULL_NONE:
                pull = 0x01;
                break;
        case S3C_GPIO_PULL_UP:
                pull = 0x00;
                break;
        case S3C_GPIO_PULL_DOWN:
                pull = 0x02;
                break;
        }
        return samsung_gpio_setpull_updown(chip, off, pull);
}

samsung_gpio_pull_t s3c2443_gpio_getpull(struct samsung_gpio_chip *chip,
                                         unsigned int off)
{
        samsung_gpio_pull_t pull;

        pull = samsung_gpio_getpull_updown(chip, off);

        switch (pull) {
        case 0x00:
                pull = S3C_GPIO_PULL_UP;
                break;
        case 0x01:
        case 0x03:
                pull = S3C_GPIO_PULL_NONE;
                break;
        case 0x02:
                pull = S3C_GPIO_PULL_DOWN;
                break;
        }

        return pull;
}

static int s3c24xx_gpio_setpull_1(struct samsung_gpio_chip *chip,
                                  unsigned int off, samsung_gpio_pull_t pull,
                                  samsung_gpio_pull_t updown)
{
        void __iomem *reg = chip->base + 0x08;
        u32 pup = __raw_readl(reg);

        if (pull == updown)
                pup &= ~(1 << off);
        else if (pull == S3C_GPIO_PULL_NONE)
                pup |= (1 << off);
        else
                return -EINVAL;

        __raw_writel(pup, reg);
        return 0;
}

static samsung_gpio_pull_t s3c24xx_gpio_getpull_1(struct samsung_gpio_chip *chip,
                                                  unsigned int off,
                                                  samsung_gpio_pull_t updown)
{
        void __iomem *reg = chip->base + 0x08;
        u32 pup = __raw_readl(reg);

        pup &= (1 << off);
        return pup ? S3C_GPIO_PULL_NONE : updown;
}

samsung_gpio_pull_t s3c24xx_gpio_getpull_1up(struct samsung_gpio_chip *chip,
                                             unsigned int off)
{
        return s3c24xx_gpio_getpull_1(chip, off, S3C_GPIO_PULL_UP);
}

int s3c24xx_gpio_setpull_1up(struct samsung_gpio_chip *chip,
                             unsigned int off, samsung_gpio_pull_t pull)
{
        return s3c24xx_gpio_setpull_1(chip, off, pull, S3C_GPIO_PULL_UP);
}

samsung_gpio_pull_t s3c24xx_gpio_getpull_1down(struct samsung_gpio_chip *chip,
                                               unsigned int off)
{
        return s3c24xx_gpio_getpull_1(chip, off, S3C_GPIO_PULL_DOWN);
}

int s3c24xx_gpio_setpull_1down(struct samsung_gpio_chip *chip,
                               unsigned int off, samsung_gpio_pull_t pull)
{
        return s3c24xx_gpio_setpull_1(chip, off, pull, S3C_GPIO_PULL_DOWN);
}

/*
 * samsung_gpio_setcfg_2bit - Samsung 2bit style GPIO configuration.
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 * @cfg: The configuration value to set.
 *
 * This helper deal with the GPIO cases where the control register
 * has two bits of configuration per gpio, which have the following
 * functions:
 *      00 = input
 *      01 = output
 *      1x = special function
 */

static int samsung_gpio_setcfg_2bit(struct samsung_gpio_chip *chip,
                                    unsigned int off, unsigned int cfg)
{
        void __iomem *reg = chip->base;
        unsigned int shift = off * 2;
        u32 con;

        if (samsung_gpio_is_cfg_special(cfg)) {
                cfg &= 0xf;
                if (cfg > 3)
                        return -EINVAL;

                cfg <<= shift;
        }

        con = __raw_readl(reg);
        con &= ~(0x3 << shift);
        con |= cfg;
        __raw_writel(con, reg);

        return 0;
}

/*
 * samsung_gpio_getcfg_2bit - Samsung 2bit style GPIO configuration read.
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 *
 * The reverse of samsung_gpio_setcfg_2bit(). Will return a value which
 * could be directly passed back to samsung_gpio_setcfg_2bit(), from the
 * S3C_GPIO_SPECIAL() macro.
 */

static unsigned int samsung_gpio_getcfg_2bit(struct samsung_gpio_chip *chip,
                                             unsigned int off)
{
        u32 con;

        con = __raw_readl(chip->base);
        con >>= off * 2;
        con &= 3;

        /* this conversion works for IN and OUT as well as special mode */
        return S3C_GPIO_SPECIAL(con);
}

/*
 * samsung_gpio_setcfg_4bit - Samsung 4bit single register GPIO config.
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 * @cfg: The configuration value to set.
 *
 * This helper deal with the GPIO cases where the control register has 4 bits
 * of control per GPIO, generally in the form of:
 *      0000 = Input
 *      0001 = Output
 *      others = Special functions (dependent on bank)
 *
 * Note, since the code to deal with the case where there are two control
 * registers instead of one, we do not have a separate set of functions for
 * each case.
 */

static int samsung_gpio_setcfg_4bit(struct samsung_gpio_chip *chip,
                                    unsigned int off, unsigned int cfg)
{
        void __iomem *reg = chip->base;
        unsigned int shift = (off & 7) * 4;
        u32 con;

        if (off < 8 && chip->chip.ngpio > 8)
                reg -= 4;

        if (samsung_gpio_is_cfg_special(cfg)) {
                cfg &= 0xf;
                cfg <<= shift;
        }

        con = __raw_readl(reg);
        con &= ~(0xf << shift);
        con |= cfg;
        __raw_writel(con, reg);

        return 0;
}

/*
 * samsung_gpio_getcfg_4bit - Samsung 4bit single register GPIO config read.
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 *
 * The reverse of samsung_gpio_setcfg_4bit(), turning a gpio configuration
 * register setting into a value the software can use, such as could be passed
 * to samsung_gpio_setcfg_4bit().
 *
 * @sa samsung_gpio_getcfg_2bit
 */

static unsigned samsung_gpio_getcfg_4bit(struct samsung_gpio_chip *chip,
                                         unsigned int off)
{
        void __iomem *reg = chip->base;
        unsigned int shift = (off & 7) * 4;
        u32 con;

        if (off < 8 && chip->chip.ngpio > 8)
                reg -= 4;

        con = __raw_readl(reg);
        con >>= shift;
        con &= 0xf;

        /* this conversion works for IN and OUT as well as special mode */
        return S3C_GPIO_SPECIAL(con);
}

#ifdef CONFIG_PLAT_S3C24XX
/*
 * s3c24xx_gpio_setcfg_abank - S3C24XX style GPIO configuration (Bank A)
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 * @cfg: The configuration value to set.
 *
 * This helper deal with the GPIO cases where the control register
 * has one bit of configuration for the gpio, where setting the bit
 * means the pin is in special function mode and unset means output.
 */

static int s3c24xx_gpio_setcfg_abank(struct samsung_gpio_chip *chip,
                                     unsigned int off, unsigned int cfg)
{
        void __iomem *reg = chip->base;
        unsigned int shift = off;
        u32 con;

        if (samsung_gpio_is_cfg_special(cfg)) {
                cfg &= 0xf;

                /* Map output to 0, and SFN2 to 1 */
                cfg -= 1;
                if (cfg > 1)
                        return -EINVAL;

                cfg <<= shift;
        }

        con = __raw_readl(reg);
        con &= ~(0x1 << shift);
        con |= cfg;
        __raw_writel(con, reg);

        return 0;
}

/*
 * s3c24xx_gpio_getcfg_abank - S3C24XX style GPIO configuration read (Bank A)
 * @chip: The gpio chip that is being configured.
 * @off: The offset for the GPIO being configured.
 *
 * The reverse of s3c24xx_gpio_setcfg_abank() turning an GPIO into a usable
 * GPIO configuration value.
 *
 * @sa samsung_gpio_getcfg_2bit
 * @sa samsung_gpio_getcfg_4bit
 */

static unsigned s3c24xx_gpio_getcfg_abank(struct samsung_gpio_chip *chip,
                                          unsigned int off)
{
        u32 con;

        con = __raw_readl(chip->base);
        con >>= off;
        con &= 1;
        con++;

        return S3C_GPIO_SFN(con);
}
#endif

static void __init samsung_gpiolib_set_cfg(struct samsung_gpio_cfg *chipcfg,
                                           int nr_chips)
{
        for (; nr_chips > 0; nr_chips--, chipcfg++) {
                if (!chipcfg->set_config)
                        chipcfg->set_config = samsung_gpio_setcfg_4bit;
                if (!chipcfg->get_config)
                        chipcfg->get_config = samsung_gpio_getcfg_4bit;
                if (!chipcfg->set_pull)
                        chipcfg->set_pull = samsung_gpio_setpull_updown;
                if (!chipcfg->get_pull)
                        chipcfg->get_pull = samsung_gpio_getpull_updown;
        }
}

struct samsung_gpio_cfg s3c24xx_gpiocfg_default = {
        .set_config     = samsung_gpio_setcfg_2bit,
        .get_config     = samsung_gpio_getcfg_2bit,
};

#ifdef CONFIG_PLAT_S3C24XX
static struct samsung_gpio_cfg s3c24xx_gpiocfg_banka = {
        .set_config     = s3c24xx_gpio_setcfg_abank,
        .get_config     = s3c24xx_gpio_getcfg_abank,
};
#endif

static struct samsung_gpio_cfg samsung_gpio_cfgs[] = {
        [0] = {
                .cfg_eint       = 0x0,
        },
        [1] = {
                .cfg_eint       = 0x3,
        },
        [2] = {
                .cfg_eint       = 0x7,
        },
        [3] = {
                .cfg_eint       = 0xF,
        },
        [4] = {
                .cfg_eint       = 0x0,
                .set_config     = samsung_gpio_setcfg_2bit,
                .get_config     = samsung_gpio_getcfg_2bit,
        },
        [5] = {
                .cfg_eint       = 0x2,
                .set_config     = samsung_gpio_setcfg_2bit,
                .get_config     = samsung_gpio_getcfg_2bit,
        },
        [6] = {
                .cfg_eint       = 0x3,
                .set_config     = samsung_gpio_setcfg_2bit,
                .get_config     = samsung_gpio_getcfg_2bit,
        },
        [7] = {
                .set_config     = samsung_gpio_setcfg_2bit,
                .get_config     = samsung_gpio_getcfg_2bit,
        },
};

/*
 * Default routines for controlling GPIO, based on the original S3C24XX
 * GPIO functions which deal with the case where each gpio bank of the
 * chip is as following:
 *
 * base + 0x00: Control register, 2 bits per gpio
 *              gpio n: 2 bits starting at (2*n)
 *              00 = input, 01 = output, others mean special-function
 * base + 0x04: Data register, 1 bit per gpio
 *              bit n: data bit n
*/

static int samsung_gpiolib_2bit_input(struct gpio_chip *chip, unsigned offset)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long flags;
        unsigned long con;

        samsung_gpio_lock(ourchip, flags);

        con = __raw_readl(base + 0x00);
        con &= ~(3 << (offset * 2));

        __raw_writel(con, base + 0x00);

        samsung_gpio_unlock(ourchip, flags);
        return 0;
}

static int samsung_gpiolib_2bit_output(struct gpio_chip *chip,
                                       unsigned offset, int value)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long flags;
        unsigned long dat;
        unsigned long con;

        samsung_gpio_lock(ourchip, flags);

        dat = __raw_readl(base + 0x04);
        dat &= ~(1 << offset);
        if (value)
                dat |= 1 << offset;
        __raw_writel(dat, base + 0x04);

        con = __raw_readl(base + 0x00);
        con &= ~(3 << (offset * 2));
        con |= 1 << (offset * 2);

        __raw_writel(con, base + 0x00);
        __raw_writel(dat, base + 0x04);

        samsung_gpio_unlock(ourchip, flags);
        return 0;
}

/*
 * The samsung_gpiolib_4bit routines are to control the gpio banks where
 * the gpio configuration register (GPxCON) has 4 bits per GPIO, as the
 * following example:
 *
 * base + 0x00: Control register, 4 bits per gpio
 *              gpio n: 4 bits starting at (4*n)
 *              0000 = input, 0001 = output, others mean special-function
 * base + 0x04: Data register, 1 bit per gpio
 *              bit n: data bit n
 *
 * Note, since the data register is one bit per gpio and is at base + 0x4
 * we can use samsung_gpiolib_get and samsung_gpiolib_set to change the
 * state of the output.
 */

static int samsung_gpiolib_4bit_input(struct gpio_chip *chip,
                                      unsigned int offset)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long con;

        con = __raw_readl(base + GPIOCON_OFF);
        if (ourchip->bitmap_gpio_int & BIT(offset))
                con |= 0xf << con_4bit_shift(offset);
        else
                con &= ~(0xf << con_4bit_shift(offset));
        __raw_writel(con, base + GPIOCON_OFF);

        pr_debug("%s: %p: CON now %08lx\n", __func__, base, con);

        return 0;
}

static int samsung_gpiolib_4bit_output(struct gpio_chip *chip,
                                       unsigned int offset, int value)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long con;
        unsigned long dat;

        con = __raw_readl(base + GPIOCON_OFF);
        con &= ~(0xf << con_4bit_shift(offset));
        con |= 0x1 << con_4bit_shift(offset);

        dat = __raw_readl(base + GPIODAT_OFF);

        if (value)
                dat |= 1 << offset;
        else
                dat &= ~(1 << offset);

        __raw_writel(dat, base + GPIODAT_OFF);
        __raw_writel(con, base + GPIOCON_OFF);
        __raw_writel(dat, base + GPIODAT_OFF);

        pr_debug("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);

        return 0;
}

/*
 * The next set of routines are for the case where the GPIO configuration
 * registers are 4 bits per GPIO but there is more than one register (the
 * bank has more than 8 GPIOs.
 *
 * This case is the similar to the 4 bit case, but the registers are as
 * follows:
 *
 * base + 0x00: Control register, 4 bits per gpio (lower 8 GPIOs)
 *              gpio n: 4 bits starting at (4*n)
 *              0000 = input, 0001 = output, others mean special-function
 * base + 0x04: Control register, 4 bits per gpio (up to 8 additions GPIOs)
 *              gpio n: 4 bits starting at (4*n)
 *              0000 = input, 0001 = output, others mean special-function
 * base + 0x08: Data register, 1 bit per gpio
 *              bit n: data bit n
 *
 * To allow us to use the samsung_gpiolib_get and samsung_gpiolib_set
 * routines we store the 'base + 0x4' address so that these routines see
 * the data register at ourchip->base + 0x04.
 */

static int samsung_gpiolib_4bit2_input(struct gpio_chip *chip,
                                       unsigned int offset)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        void __iomem *regcon = base;
        unsigned long con;

        if (offset > 7)
                offset -= 8;
        else
                regcon -= 4;

        con = __raw_readl(regcon);
        con &= ~(0xf << con_4bit_shift(offset));
        __raw_writel(con, regcon);

        pr_debug("%s: %p: CON %08lx\n", __func__, base, con);

        return 0;
}

static int samsung_gpiolib_4bit2_output(struct gpio_chip *chip,
                                        unsigned int offset, int value)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        void __iomem *regcon = base;
        unsigned long con;
        unsigned long dat;
        unsigned con_offset = offset;

        if (con_offset > 7)
                con_offset -= 8;
        else
                regcon -= 4;

        con = __raw_readl(regcon);
        con &= ~(0xf << con_4bit_shift(con_offset));
        con |= 0x1 << con_4bit_shift(con_offset);

        dat = __raw_readl(base + GPIODAT_OFF);

        if (value)
                dat |= 1 << offset;
        else
                dat &= ~(1 << offset);

        __raw_writel(dat, base + GPIODAT_OFF);
        __raw_writel(con, regcon);
        __raw_writel(dat, base + GPIODAT_OFF);

        pr_debug("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);

        return 0;
}

#ifdef CONFIG_PLAT_S3C24XX
/* The next set of routines are for the case of s3c24xx bank a */

static int s3c24xx_gpiolib_banka_input(struct gpio_chip *chip, unsigned offset)
{
        return -EINVAL;
}

static int s3c24xx_gpiolib_banka_output(struct gpio_chip *chip,
                                        unsigned offset, int value)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long flags;
        unsigned long dat;
        unsigned long con;

        local_irq_save(flags);

        con = __raw_readl(base + 0x00);
        dat = __raw_readl(base + 0x04);

        dat &= ~(1 << offset);
        if (value)
                dat |= 1 << offset;

        __raw_writel(dat, base + 0x04);

        con &= ~(1 << offset);

        __raw_writel(con, base + 0x00);
        __raw_writel(dat, base + 0x04);

        local_irq_restore(flags);
        return 0;
}
#endif

static void samsung_gpiolib_set(struct gpio_chip *chip,
                                unsigned offset, int value)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        void __iomem *base = ourchip->base;
        unsigned long flags;
        unsigned long dat;

        samsung_gpio_lock(ourchip, flags);

        dat = __raw_readl(base + 0x04);
        dat &= ~(1 << offset);
        if (value)
                dat |= 1 << offset;
        __raw_writel(dat, base + 0x04);

        samsung_gpio_unlock(ourchip, flags);
}

static int samsung_gpiolib_get(struct gpio_chip *chip, unsigned offset)
{
        struct samsung_gpio_chip *ourchip = to_samsung_gpio(chip);
        unsigned long val;

        val = __raw_readl(ourchip->base + 0x04);
        val >>= offset;
        val &= 1;

        return val;
}

/*
 * CONFIG_S3C_GPIO_TRACK enables the tracking of the s3c specific gpios
 * for use with the configuration calls, and other parts of the s3c gpiolib
 * support code.
 *
 * Not all s3c support code will need this, as some configurations of cpu
 * may only support one or two different configuration options and have an
 * easy gpio to samsung_gpio_chip mapping function. If this is the case, then
 * the machine support file should provide its own samsung_gpiolib_getchip()
 * and any other necessary functions.
 */

#ifdef CONFIG_S3C_GPIO_TRACK
struct samsung_gpio_chip *s3c_gpios[S3C_GPIO_END];

static __init void s3c_gpiolib_track(struct samsung_gpio_chip *chip)
{
        unsigned int gpn;
        int i;

        gpn = chip->chip.base;
        for (i = 0; i < chip->chip.ngpio; i++, gpn++) {
                BUG_ON(gpn >= ARRAY_SIZE(s3c_gpios));
                s3c_gpios[gpn] = chip;
        }
}
#endif /* CONFIG_S3C_GPIO_TRACK */

/*
 * samsung_gpiolib_add() - add the Samsung gpio_chip.
 * @chip: The chip to register
 *
 * This is a wrapper to gpiochip_add() that takes our specific gpio chip
 * information and makes the necessary alterations for the platform and
 * notes the information for use with the configuration systems and any
 * other parts of the system.
 */

static void __init samsung_gpiolib_add(struct samsung_gpio_chip *chip)
{
        struct gpio_chip *gc = &chip->chip;
        int ret;

        BUG_ON(!chip->base);
        BUG_ON(!gc->label);
        BUG_ON(!gc->ngpio);

        spin_lock_init(&chip->lock);

        if (!gc->direction_input)
                gc->direction_input = samsung_gpiolib_2bit_input;
        if (!gc->direction_output)
                gc->direction_output = samsung_gpiolib_2bit_output;
        if (!gc->set)
                gc->set = samsung_gpiolib_set;
        if (!gc->get)
                gc->get = samsung_gpiolib_get;

#ifdef CONFIG_PM
        if (chip->pm != NULL) {
                if (!chip->pm->save || !chip->pm->resume)
                        pr_err("gpio: %s has missing PM functions\n",
                               gc->label);
        } else
                pr_err("gpio: %s has no PM function\n", gc->label);
#endif

        /* gpiochip_add() prints own failure message on error. */
        ret = gpiochip_add_data(gc, chip);
        if (ret >= 0)
                s3c_gpiolib_track(chip);
}

static void __init s3c24xx_gpiolib_add_chips(struct samsung_gpio_chip *chip,
                                             int nr_chips, void __iomem *base)
{
        int i;
        struct gpio_chip *gc = &chip->chip;

        for (i = 0 ; i < nr_chips; i++, chip++) {
                /* skip banks not present on SoC */
                if (chip->chip.base >= S3C_GPIO_END)
                        continue;

                if (!chip->config)
                        chip->config = &s3c24xx_gpiocfg_default;
                if (!chip->pm)
                        chip->pm = __gpio_pm(&samsung_gpio_pm_2bit);
                if ((base != NULL) && (chip->base == NULL))
                        chip->base = base + ((i) * 0x10);

                if (!gc->direction_input)
                        gc->direction_input = samsung_gpiolib_2bit_input;
                if (!gc->direction_output)
                        gc->direction_output = samsung_gpiolib_2bit_output;

                samsung_gpiolib_add(chip);
        }
}

static void __init samsung_gpiolib_add_2bit_chips(struct samsung_gpio_chip *chip,
                                                  int nr_chips, void __iomem *base,
                                                  unsigned int offset)
{
        int i;

        for (i = 0 ; i < nr_chips; i++, chip++) {
                chip->chip.direction_input = samsung_gpiolib_2bit_input;
                chip->chip.direction_output = samsung_gpiolib_2bit_output;

                if (!chip->config)
                        chip->config = &samsung_gpio_cfgs[7];
                if (!chip->pm)
                        chip->pm = __gpio_pm(&samsung_gpio_pm_2bit);
                if ((base != NULL) && (chip->base == NULL))
                        chip->base = base + ((i) * offset);

                samsung_gpiolib_add(chip);
        }
}

/*
 * samsung_gpiolib_add_4bit_chips - 4bit single register GPIO config.
 * @chip: The gpio chip that is being configured.
 * @nr_chips: The no of chips (gpio ports) for the GPIO being configured.
 *
 * This helper deal with the GPIO cases where the control register has 4 bits
 * of control per GPIO, generally in the form of:
 * 0000 = Input
 * 0001 = Output
 * others = Special functions (dependent on bank)
 *
 * Note, since the code to deal with the case where there are two control
 * registers instead of one, we do not have a separate set of function
 * (samsung_gpiolib_add_4bit2_chips)for each case.
 */

static void __init samsung_gpiolib_add_4bit_chips(struct samsung_gpio_chip *chip,
                                                  int nr_chips, void __iomem *base)
{
        int i;

        for (i = 0 ; i < nr_chips; i++, chip++) {
                chip->chip.direction_input = samsung_gpiolib_4bit_input;
                chip->chip.direction_output = samsung_gpiolib_4bit_output;

                if (!chip->config)
                        chip->config = &samsung_gpio_cfgs[2];
                if (!chip->pm)
                        chip->pm = __gpio_pm(&samsung_gpio_pm_4bit);
                if ((base != NULL) && (chip->base == NULL))
                        chip->base = base + ((i) * 0x20);

                chip->bitmap_gpio_int = 0;

                samsung_gpiolib_add(chip);
        }
}

static void __init samsung_gpiolib_add_4bit2_chips(struct samsung_gpio_chip *chip,
                                                   int nr_chips)
{
        for (; nr_chips > 0; nr_chips--, chip++) {
                chip->chip.direction_input = samsung_gpiolib_4bit2_input;
                chip->chip.direction_output = samsung_gpiolib_4bit2_output;

                if (!chip->config)
                        chip->config = &samsung_gpio_cfgs[2];
                if (!chip->pm)
                        chip->pm = __gpio_pm(&samsung_gpio_pm_4bit);

                samsung_gpiolib_add(chip);
        }
}

int samsung_gpiolib_to_irq(struct gpio_chip *chip, unsigned int offset)
{
        struct samsung_gpio_chip *samsung_chip = gpiochip_get_data(chip);

        return samsung_chip->irq_base + offset;
}

#ifdef CONFIG_PLAT_S3C24XX
static int s3c24xx_gpiolib_fbank_to_irq(struct gpio_chip *chip, unsigned offset)
{
        if (offset < 4) {
                if (soc_is_s3c2412())
                        return IRQ_EINT0_2412 + offset;
                else
                        return IRQ_EINT0 + offset;
        }

        if (offset < 8)
                return IRQ_EINT4 + offset - 4;

        return -EINVAL;
}
#endif

#ifdef CONFIG_ARCH_S3C64XX
static int s3c64xx_gpiolib_mbank_to_irq(struct gpio_chip *chip, unsigned pin)
{
        return pin < 5 ? IRQ_EINT(23) + pin : -ENXIO;
}

static int s3c64xx_gpiolib_lbank_to_irq(struct gpio_chip *chip, unsigned pin)
{
        return pin >= 8 ? IRQ_EINT(16) + pin - 8 : -ENXIO;
}
#endif

struct samsung_gpio_chip s3c24xx_gpios[] = {
#ifdef CONFIG_PLAT_S3C24XX
        {
                .config = &s3c24xx_gpiocfg_banka,
                .chip   = {
                        .base                   = S3C2410_GPA(0),
                        .owner                  = THIS_MODULE,
                        .label                  = "GPIOA",
                        .ngpio                  = 27,
                        .direction_input        = s3c24xx_gpiolib_banka_input,
                        .direction_output       = s3c24xx_gpiolib_banka_output,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPB(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOB",
                        .ngpio  = 11,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPC(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOC",
                        .ngpio  = 16,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPD(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOD",
                        .ngpio  = 16,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPE(0),
                        .label  = "GPIOE",
                        .owner  = THIS_MODULE,
                        .ngpio  = 16,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPF(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOF",
                        .ngpio  = 8,
                        .to_irq = s3c24xx_gpiolib_fbank_to_irq,
                },
        }, {
                .irq_base = IRQ_EINT8,
                .chip   = {
                        .base   = S3C2410_GPG(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOG",
                        .ngpio  = 16,
                        .to_irq = samsung_gpiolib_to_irq,
                },
        }, {
                .chip   = {
                        .base   = S3C2410_GPH(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOH",
                        .ngpio  = 15,
                },
        },
                /* GPIOS for the S3C2443 and later devices. */
        {
                .base   = S3C2440_GPJCON,
                .chip   = {
                        .base   = S3C2410_GPJ(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOJ",
                        .ngpio  = 16,
                },
        }, {
                .base   = S3C2443_GPKCON,
                .chip   = {
                        .base   = S3C2410_GPK(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOK",
                        .ngpio  = 16,
                },
        }, {
                .base   = S3C2443_GPLCON,
                .chip   = {
                        .base   = S3C2410_GPL(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOL",
                        .ngpio  = 15,
                },
        }, {
                .base   = S3C2443_GPMCON,
                .chip   = {
                        .base   = S3C2410_GPM(0),
                        .owner  = THIS_MODULE,
                        .label  = "GPIOM",
                        .ngpio  = 2,
                },
        },
#endif
};

/*
 * GPIO bank summary:
 *
 * Bank GPIOs   Style   SlpCon  ExtInt Group
 * A    8       4Bit    Yes     1
 * B    7       4Bit    Yes     1
 * C    8       4Bit    Yes     2
 * D    5       4Bit    Yes     3
 * E    5       4Bit    Yes     None
 * F    16      2Bit    Yes     4 [1]
 * G    7       4Bit    Yes     5
 * H    10      4Bit[2] Yes     6
 * I    16      2Bit    Yes     None
 * J    12      2Bit    Yes     None
 * K    16      4Bit[2] No      None
 * L    15      4Bit[2] No      None
 * M    6       4Bit    No      IRQ_EINT
 * N    16      2Bit    No      IRQ_EINT
 * O    16      2Bit    Yes     7
 * P    15      2Bit    Yes     8
 * Q    9       2Bit    Yes     9
 *
 * [1] BANKF pins 14,15 do not form part of the external interrupt sources
 * [2] BANK has two control registers, GPxCON0 and GPxCON1
 */

static struct samsung_gpio_chip s3c64xx_gpios_4bit[] = {
#ifdef CONFIG_ARCH_S3C64XX
        {
                .chip   = {
                        .base   = S3C64XX_GPA(0),
                        .ngpio  = S3C64XX_GPIO_A_NR,
                        .label  = "GPA",
                },
        }, {
                .chip   = {
                        .base   = S3C64XX_GPB(0),
                        .ngpio  = S3C64XX_GPIO_B_NR,
                        .label  = "GPB",
                },
        }, {
                .chip   = {
                        .base   = S3C64XX_GPC(0),
                        .ngpio  = S3C64XX_GPIO_C_NR,
                        .label  = "GPC",
                },
        }, {
                .chip   = {
                        .base   = S3C64XX_GPD(0),
                        .ngpio  = S3C64XX_GPIO_D_NR,
                        .label  = "GPD",
                },
        }, {
                .config = &samsung_gpio_cfgs[0],
                .chip   = {
                        .base   = S3C64XX_GPE(0),
                        .ngpio  = S3C64XX_GPIO_E_NR,
                        .label  = "GPE",
                },
        }, {
                .base   = S3C64XX_GPG_BASE,
                .chip   = {
                        .base   = S3C64XX_GPG(0),
                        .ngpio  = S3C64XX_GPIO_G_NR,
                        .label  = "GPG",
                },
        }, {
                .base   = S3C64XX_GPM_BASE,
                .config = &samsung_gpio_cfgs[1],
                .chip   = {
                        .base   = S3C64XX_GPM(0),
                        .ngpio  = S3C64XX_GPIO_M_NR,
                        .label  = "GPM",
                        .to_irq = s3c64xx_gpiolib_mbank_to_irq,
                },
        },
#endif
};

static struct samsung_gpio_chip s3c64xx_gpios_4bit2[] = {
#ifdef CONFIG_ARCH_S3C64XX
        {
                .base   = S3C64XX_GPH_BASE + 0x4,
                .chip   = {
                        .base   = S3C64XX_GPH(0),
                        .ngpio  = S3C64XX_GPIO_H_NR,
                        .label  = "GPH",
                },
        }, {
                .base   = S3C64XX_GPK_BASE + 0x4,
                .config = &samsung_gpio_cfgs[0],
                .chip   = {
                        .base   = S3C64XX_GPK(0),
                        .ngpio  = S3C64XX_GPIO_K_NR,
                        .label  = "GPK",
                },
        }, {
                .base   = S3C64XX_GPL_BASE + 0x4,
                .config = &samsung_gpio_cfgs[1],
                .chip   = {
                        .base   = S3C64XX_GPL(0),
                        .ngpio  = S3C64XX_GPIO_L_NR,
                        .label  = "GPL",
                        .to_irq = s3c64xx_gpiolib_lbank_to_irq,
                },
        },
#endif
};

static struct samsung_gpio_chip s3c64xx_gpios_2bit[] = {
#ifdef CONFIG_ARCH_S3C64XX
        {
                .base   = S3C64XX_GPF_BASE,
                .config = &samsung_gpio_cfgs[6],
                .chip   = {
                        .base   = S3C64XX_GPF(0),
                        .ngpio  = S3C64XX_GPIO_F_NR,
                        .label  = "GPF",
                },
        }, {
                .config = &samsung_gpio_cfgs[7],
                .chip   = {
                        .base   = S3C64XX_GPI(0),
                        .ngpio  = S3C64XX_GPIO_I_NR,
                        .label  = "GPI",
                },
        }, {
                .config = &samsung_gpio_cfgs[7],
                .chip   = {
                        .base   = S3C64XX_GPJ(0),
                        .ngpio  = S3C64XX_GPIO_J_NR,
                        .label  = "GPJ",
                },
        }, {
                .config = &samsung_gpio_cfgs[6],
                .chip   = {
                        .base   = S3C64XX_GPO(0),
                        .ngpio  = S3C64XX_GPIO_O_NR,
                        .label  = "GPO",
                },
        }, {
                .config = &samsung_gpio_cfgs[6],
                .chip   = {
                        .base   = S3C64XX_GPP(0),
                        .ngpio  = S3C64XX_GPIO_P_NR,
                        .label  = "GPP",
                },
        }, {
                .config = &samsung_gpio_cfgs[6],
                .chip   = {
                        .base   = S3C64XX_GPQ(0),
                        .ngpio  = S3C64XX_GPIO_Q_NR,
                        .label  = "GPQ",
                },
        }, {
                .base   = S3C64XX_GPN_BASE,
                .irq_base = IRQ_EINT(0),
                .config = &samsung_gpio_cfgs[5],
                .chip   = {
                        .base   = S3C64XX_GPN(0),
                        .ngpio  = S3C64XX_GPIO_N_NR,
                        .label  = "GPN",
                        .to_irq = samsung_gpiolib_to_irq,
                },
        },
#endif
};

/* TODO: cleanup soc_is_* */
static __init int samsung_gpiolib_init(void)
{
        /*
         * Currently there are two drivers that can provide GPIO support for
         * Samsung SoCs. For device tree enabled platforms, the new
         * pinctrl-samsung driver is used, providing both GPIO and pin control
         * interfaces. For legacy (non-DT) platforms this driver is used.
         */
        if (of_have_populated_dt())
                return 0;

        if (soc_is_s3c24xx()) {
                samsung_gpiolib_set_cfg(samsung_gpio_cfgs,
                                ARRAY_SIZE(samsung_gpio_cfgs));
                s3c24xx_gpiolib_add_chips(s3c24xx_gpios,
                                ARRAY_SIZE(s3c24xx_gpios), S3C24XX_VA_GPIO);
        } else if (soc_is_s3c64xx()) {
                samsung_gpiolib_set_cfg(samsung_gpio_cfgs,
                                ARRAY_SIZE(samsung_gpio_cfgs));
                samsung_gpiolib_add_2bit_chips(s3c64xx_gpios_2bit,
                                ARRAY_SIZE(s3c64xx_gpios_2bit),
                                S3C64XX_VA_GPIO + 0xE0, 0x20);
                samsung_gpiolib_add_4bit_chips(s3c64xx_gpios_4bit,
                                ARRAY_SIZE(s3c64xx_gpios_4bit),
                                S3C64XX_VA_GPIO);
                samsung_gpiolib_add_4bit2_chips(s3c64xx_gpios_4bit2,
                                ARRAY_SIZE(s3c64xx_gpios_4bit2));
        }

        return 0;
}
core_initcall(samsung_gpiolib_init);

int s3c_gpio_cfgpin(unsigned int pin, unsigned int config)
{
        struct samsung_gpio_chip *chip = samsung_gpiolib_getchip(pin);
        unsigned long flags;
        int offset;
        int ret;

        if (!chip)
                return -EINVAL;

        offset = pin - chip->chip.base;

        samsung_gpio_lock(chip, flags);
        ret = samsung_gpio_do_setcfg(chip, offset, config);
        samsung_gpio_unlock(chip, flags);

        return ret;
}
EXPORT_SYMBOL(s3c_gpio_cfgpin);

int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr,
                          unsigned int cfg)
{
        int ret;

        for (; nr > 0; nr--, start++) {
                ret = s3c_gpio_cfgpin(start, cfg);
                if (ret != 0)
                        return ret;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(s3c_gpio_cfgpin_range);

int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr,
                          unsigned int cfg, samsung_gpio_pull_t pull)
{
        int ret;

        for (; nr > 0; nr--, start++) {
                s3c_gpio_setpull(start, pull);
                ret = s3c_gpio_cfgpin(start, cfg);
                if (ret != 0)
                        return ret;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(s3c_gpio_cfgall_range);

unsigned s3c_gpio_getcfg(unsigned int pin)
{
        struct samsung_gpio_chip *chip = samsung_gpiolib_getchip(pin);
        unsigned long flags;
        unsigned ret = 0;
        int offset;

        if (chip) {
                offset = pin - chip->chip.base;

                samsung_gpio_lock(chip, flags);
                ret = samsung_gpio_do_getcfg(chip, offset);
                samsung_gpio_unlock(chip, flags);
        }

        return ret;
}
EXPORT_SYMBOL(s3c_gpio_getcfg);

int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull)
{
        struct samsung_gpio_chip *chip = samsung_gpiolib_getchip(pin);
        unsigned long flags;
        int offset, ret;

        if (!chip)
                return -EINVAL;

        offset = pin - chip->chip.base;

        samsung_gpio_lock(chip, flags);
        ret = samsung_gpio_do_setpull(chip, offset, pull);
        samsung_gpio_unlock(chip, flags);

        return ret;
}
EXPORT_SYMBOL(s3c_gpio_setpull);

samsung_gpio_pull_t s3c_gpio_getpull(unsigned int pin)
{
        struct samsung_gpio_chip *chip = samsung_gpiolib_getchip(pin);
        unsigned long flags;
        int offset;
        u32 pup = 0;

        if (chip) {
                offset = pin - chip->chip.base;

                samsung_gpio_lock(chip, flags);
                pup = samsung_gpio_do_getpull(chip, offset);
                samsung_gpio_unlock(chip, flags);
        }

        return (__force samsung_gpio_pull_t)pup;
}
EXPORT_SYMBOL(s3c_gpio_getpull);

#ifdef CONFIG_PLAT_S3C24XX
unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change)
{
        unsigned long flags;
        unsigned long misccr;

        local_irq_save(flags);
        misccr = __raw_readl(S3C24XX_MISCCR);
        misccr &= ~clear;
        misccr ^= change;
        __raw_writel(misccr, S3C24XX_MISCCR);
        local_irq_restore(flags);

        return misccr;
}
EXPORT_SYMBOL(s3c2410_modify_misccr);
#endif