// SPDX-License-Identifier: GPL-2.0+
//
// RTC driver for Maxim MAX77686 and MAX77802
//
// Copyright (C) 2012 Samsung Electronics Co.Ltd
//
//  based on rtc-max8997.c

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/max77686-private.h>
#include <linux/irqdomain.h>
#include <linux/regmap.h>

#define MAX77686_I2C_ADDR_RTC           (0x0C >> 1)
#define MAX77620_I2C_ADDR_RTC           0x68
#define MAX77714_I2C_ADDR_RTC           0x48
#define MAX77686_INVALID_I2C_ADDR       (-1)

/* Define non existing register */
#define MAX77686_INVALID_REG            (-1)

/* RTC Control Register */
#define BCD_EN_SHIFT                    0
#define BCD_EN_MASK                     BIT(BCD_EN_SHIFT)
#define MODEL24_SHIFT                   1
#define MODEL24_MASK                    BIT(MODEL24_SHIFT)
/* RTC Update Register1 */
#define RTC_UDR_SHIFT                   0
#define RTC_UDR_MASK                    BIT(RTC_UDR_SHIFT)
#define RTC_RBUDR_SHIFT                 4
#define RTC_RBUDR_MASK                  BIT(RTC_RBUDR_SHIFT)
/* RTC Alarm Enable */
#define ALARM_ENABLE_SHIFT              7
#define ALARM_ENABLE_MASK               BIT(ALARM_ENABLE_SHIFT)

#define REG_RTC_NONE                    0xdeadbeef

/*
 * MAX77802 has separate register (RTCAE1) for alarm enable instead
 * using 1 bit from registers RTC{SEC,MIN,HOUR,DAY,MONTH,YEAR,DATE}
 * as in done in MAX77686.
 */
#define MAX77802_ALARM_ENABLE_VALUE     0x77

enum {
        RTC_SEC = 0,
        RTC_MIN,
        RTC_HOUR,
        RTC_WEEKDAY,
        RTC_MONTH,
        RTC_YEAR,
        RTC_MONTHDAY,
        RTC_NR_TIME
};

/**
 * struct max77686_rtc_driver_data - model-specific configuration
 * @delay: Minimum usecs needed for a RTC update
 * @mask: Mask used to read RTC registers value
 * @map: Registers offset to I2C addresses map
 * @alarm_enable_reg: Has a separate alarm enable register?
 * @rtc_i2c_addr: I2C address for RTC block
 * @rtc_irq_from_platform: RTC interrupt via platform resource
 * @alarm_pending_status_reg: Pending alarm status register
 * @rtc_irq_chip: RTC IRQ CHIP for regmap
 * @regmap_config: regmap configuration for the chip
 */
struct max77686_rtc_driver_data {
        unsigned long           delay;
        u8                      mask;
        const unsigned int      *map;
        bool                    alarm_enable_reg;
        int                     rtc_i2c_addr;
        bool                    rtc_irq_from_platform;
        int                     alarm_pending_status_reg;
        const struct regmap_irq_chip *rtc_irq_chip;
        const struct regmap_config *regmap_config;
};

struct max77686_rtc_info {
        struct device           *dev;
        struct rtc_device       *rtc_dev;
        struct mutex            lock;

        struct regmap           *regmap;
        struct regmap           *rtc_regmap;

        const struct max77686_rtc_driver_data *drv_data;
        struct regmap_irq_chip_data *rtc_irq_data;

        int rtc_irq;
        int virq;
};

enum MAX77686_RTC_OP {
        MAX77686_RTC_WRITE,
        MAX77686_RTC_READ,
};

/* These are not registers but just offsets that are mapped to addresses */
enum max77686_rtc_reg_offset {
        REG_RTC_CONTROLM = 0,
        REG_RTC_CONTROL,
        REG_RTC_UPDATE0,
        REG_WTSR_SMPL_CNTL,
        REG_RTC_SEC,
        REG_RTC_MIN,
        REG_RTC_HOUR,
        REG_RTC_WEEKDAY,
        REG_RTC_MONTH,
        REG_RTC_YEAR,
        REG_RTC_MONTHDAY,
        REG_ALARM1_SEC,
        REG_ALARM1_MIN,
        REG_ALARM1_HOUR,
        REG_ALARM1_WEEKDAY,
        REG_ALARM1_MONTH,
        REG_ALARM1_YEAR,
        REG_ALARM1_DATE,
        REG_ALARM2_SEC,
        REG_ALARM2_MIN,
        REG_ALARM2_HOUR,
        REG_ALARM2_WEEKDAY,
        REG_ALARM2_MONTH,
        REG_ALARM2_YEAR,
        REG_ALARM2_DATE,
        REG_RTC_AE1,
        REG_RTC_END,
};

/* Maps RTC registers offset to the MAX77686 register addresses */
static const unsigned int max77686_map[REG_RTC_END] = {
        [REG_RTC_CONTROLM]   = MAX77686_RTC_CONTROLM,
        [REG_RTC_CONTROL]    = MAX77686_RTC_CONTROL,
        [REG_RTC_UPDATE0]    = MAX77686_RTC_UPDATE0,
        [REG_WTSR_SMPL_CNTL] = MAX77686_WTSR_SMPL_CNTL,
        [REG_RTC_SEC]        = MAX77686_RTC_SEC,
        [REG_RTC_MIN]        = MAX77686_RTC_MIN,
        [REG_RTC_HOUR]       = MAX77686_RTC_HOUR,
        [REG_RTC_WEEKDAY]    = MAX77686_RTC_WEEKDAY,
        [REG_RTC_MONTH]      = MAX77686_RTC_MONTH,
        [REG_RTC_YEAR]       = MAX77686_RTC_YEAR,
        [REG_RTC_MONTHDAY]   = MAX77686_RTC_MONTHDAY,
        [REG_ALARM1_SEC]     = MAX77686_ALARM1_SEC,
        [REG_ALARM1_MIN]     = MAX77686_ALARM1_MIN,
        [REG_ALARM1_HOUR]    = MAX77686_ALARM1_HOUR,
        [REG_ALARM1_WEEKDAY] = MAX77686_ALARM1_WEEKDAY,
        [REG_ALARM1_MONTH]   = MAX77686_ALARM1_MONTH,
        [REG_ALARM1_YEAR]    = MAX77686_ALARM1_YEAR,
        [REG_ALARM1_DATE]    = MAX77686_ALARM1_DATE,
        [REG_ALARM2_SEC]     = MAX77686_ALARM2_SEC,
        [REG_ALARM2_MIN]     = MAX77686_ALARM2_MIN,
        [REG_ALARM2_HOUR]    = MAX77686_ALARM2_HOUR,
        [REG_ALARM2_WEEKDAY] = MAX77686_ALARM2_WEEKDAY,
        [REG_ALARM2_MONTH]   = MAX77686_ALARM2_MONTH,
        [REG_ALARM2_YEAR]    = MAX77686_ALARM2_YEAR,
        [REG_ALARM2_DATE]    = MAX77686_ALARM2_DATE,
        [REG_RTC_AE1]        = REG_RTC_NONE,
};

static const struct regmap_irq max77686_rtc_irqs[] = {
        /* RTC interrupts */
        REGMAP_IRQ_REG(0, 0, MAX77686_RTCINT_RTC60S_MSK),
        REGMAP_IRQ_REG(1, 0, MAX77686_RTCINT_RTCA1_MSK),
        REGMAP_IRQ_REG(2, 0, MAX77686_RTCINT_RTCA2_MSK),
        REGMAP_IRQ_REG(3, 0, MAX77686_RTCINT_SMPL_MSK),
        REGMAP_IRQ_REG(4, 0, MAX77686_RTCINT_RTC1S_MSK),
        REGMAP_IRQ_REG(5, 0, MAX77686_RTCINT_WTSR_MSK),
};

static const struct regmap_irq_chip max77686_rtc_irq_chip = {
        .name           = "max77686-rtc",
        .status_base    = MAX77686_RTC_INT,
        .mask_base      = MAX77686_RTC_INTM,
        .num_regs       = 1,
        .irqs           = max77686_rtc_irqs,
        .num_irqs       = ARRAY_SIZE(max77686_rtc_irqs),
};

static const struct regmap_config max77686_rtc_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
};

static const struct max77686_rtc_driver_data max77686_drv_data = {
        .delay = 16000,
        .mask  = 0x7f,
        .map   = max77686_map,
        .alarm_enable_reg  = false,
        .rtc_irq_from_platform = false,
        .alarm_pending_status_reg = MAX77686_REG_STATUS2,
        .rtc_i2c_addr = MAX77686_I2C_ADDR_RTC,
        .rtc_irq_chip = &max77686_rtc_irq_chip,
        .regmap_config = &max77686_rtc_regmap_config,
};

static const struct regmap_irq_chip max77714_rtc_irq_chip = {
        .name           = "max77714-rtc",
        .status_base    = MAX77686_RTC_INT,
        .mask_base      = MAX77686_RTC_INTM,
        .num_regs       = 1,
        .irqs           = max77686_rtc_irqs,
        .num_irqs       = ARRAY_SIZE(max77686_rtc_irqs) - 1, /* no WTSR on 77714 */
};

static const struct max77686_rtc_driver_data max77714_drv_data = {
        .delay = 16000,
        .mask  = 0x7f,
        .map   = max77686_map,
        .alarm_enable_reg = false,
        .rtc_irq_from_platform = false,
        /* On MAX77714 RTCA1 is BIT 1 of RTCINT (0x00). Not supported by this driver. */
        .alarm_pending_status_reg = MAX77686_INVALID_REG,
        .rtc_i2c_addr = MAX77714_I2C_ADDR_RTC,
        .rtc_irq_chip = &max77714_rtc_irq_chip,
        .regmap_config = &max77686_rtc_regmap_config,
};

static const struct regmap_config max77620_rtc_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .use_single_write = true,
};

static const struct max77686_rtc_driver_data max77620_drv_data = {
        .delay = 16000,
        .mask  = 0x7f,
        .map   = max77686_map,
        .alarm_enable_reg  = false,
        .rtc_irq_from_platform = true,
        .alarm_pending_status_reg = MAX77686_INVALID_REG,
        .rtc_i2c_addr = MAX77620_I2C_ADDR_RTC,
        .rtc_irq_chip = &max77686_rtc_irq_chip,
        .regmap_config = &max77620_rtc_regmap_config,
};

static const unsigned int max77802_map[REG_RTC_END] = {
        [REG_RTC_CONTROLM]   = MAX77802_RTC_CONTROLM,
        [REG_RTC_CONTROL]    = MAX77802_RTC_CONTROL,
        [REG_RTC_UPDATE0]    = MAX77802_RTC_UPDATE0,
        [REG_WTSR_SMPL_CNTL] = MAX77802_WTSR_SMPL_CNTL,
        [REG_RTC_SEC]        = MAX77802_RTC_SEC,
        [REG_RTC_MIN]        = MAX77802_RTC_MIN,
        [REG_RTC_HOUR]       = MAX77802_RTC_HOUR,
        [REG_RTC_WEEKDAY]    = MAX77802_RTC_WEEKDAY,
        [REG_RTC_MONTH]      = MAX77802_RTC_MONTH,
        [REG_RTC_YEAR]       = MAX77802_RTC_YEAR,
        [REG_RTC_MONTHDAY]   = MAX77802_RTC_MONTHDAY,
        [REG_ALARM1_SEC]     = MAX77802_ALARM1_SEC,
        [REG_ALARM1_MIN]     = MAX77802_ALARM1_MIN,
        [REG_ALARM1_HOUR]    = MAX77802_ALARM1_HOUR,
        [REG_ALARM1_WEEKDAY] = MAX77802_ALARM1_WEEKDAY,
        [REG_ALARM1_MONTH]   = MAX77802_ALARM1_MONTH,
        [REG_ALARM1_YEAR]    = MAX77802_ALARM1_YEAR,
        [REG_ALARM1_DATE]    = MAX77802_ALARM1_DATE,
        [REG_ALARM2_SEC]     = MAX77802_ALARM2_SEC,
        [REG_ALARM2_MIN]     = MAX77802_ALARM2_MIN,
        [REG_ALARM2_HOUR]    = MAX77802_ALARM2_HOUR,
        [REG_ALARM2_WEEKDAY] = MAX77802_ALARM2_WEEKDAY,
        [REG_ALARM2_MONTH]   = MAX77802_ALARM2_MONTH,
        [REG_ALARM2_YEAR]    = MAX77802_ALARM2_YEAR,
        [REG_ALARM2_DATE]    = MAX77802_ALARM2_DATE,
        [REG_RTC_AE1]        = MAX77802_RTC_AE1,
};

static const struct regmap_irq_chip max77802_rtc_irq_chip = {
        .name           = "max77802-rtc",
        .status_base    = MAX77802_RTC_INT,
        .mask_base      = MAX77802_RTC_INTM,
        .num_regs       = 1,
        .irqs           = max77686_rtc_irqs, /* same masks as 77686 */
        .num_irqs       = ARRAY_SIZE(max77686_rtc_irqs),
};

static const struct max77686_rtc_driver_data max77802_drv_data = {
        .delay = 200,
        .mask  = 0xff,
        .map   = max77802_map,
        .alarm_enable_reg  = true,
        .rtc_irq_from_platform = false,
        .alarm_pending_status_reg = MAX77686_REG_STATUS2,
        .rtc_i2c_addr = MAX77686_INVALID_I2C_ADDR,
        .rtc_irq_chip = &max77802_rtc_irq_chip,
};

static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
                                    struct max77686_rtc_info *info)
{
        u8 mask = info->drv_data->mask;

        tm->tm_sec = data[RTC_SEC] & mask;
        tm->tm_min = data[RTC_MIN] & mask;
        tm->tm_hour = data[RTC_HOUR] & 0x1f;

        /* Only a single bit is set in data[], so fls() would be equivalent */
        tm->tm_wday = ffs(data[RTC_WEEKDAY] & mask) - 1;
        tm->tm_mday = data[RTC_MONTHDAY] & 0x1f;
        tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
        tm->tm_year = data[RTC_YEAR] & mask;
        tm->tm_yday = 0;
        tm->tm_isdst = 0;

        /*
         * MAX77686 uses 1 bit from sec/min/hour/etc RTC registers and the
         * year values are just 0..99 so add 100 to support up to 2099.
         */
        if (!info->drv_data->alarm_enable_reg)
                tm->tm_year += 100;
}

static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data,
                                   struct max77686_rtc_info *info)
{
        data[RTC_SEC] = tm->tm_sec;
        data[RTC_MIN] = tm->tm_min;
        data[RTC_HOUR] = tm->tm_hour;
        data[RTC_WEEKDAY] = 1 << tm->tm_wday;
        data[RTC_MONTHDAY] = tm->tm_mday;
        data[RTC_MONTH] = tm->tm_mon + 1;

        if (info->drv_data->alarm_enable_reg) {
                data[RTC_YEAR] = tm->tm_year;
                return 0;
        }

        data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;

        if (tm->tm_year < 100) {
                dev_err(info->dev, "RTC cannot handle the year %d.\n",
                        1900 + tm->tm_year);
                return -EINVAL;
        }

        return 0;
}

static int max77686_rtc_update(struct max77686_rtc_info *info,
                               enum MAX77686_RTC_OP op)
{
        int ret;
        unsigned int data;
        unsigned long delay = info->drv_data->delay;

        if (op == MAX77686_RTC_WRITE)
                data = 1 << RTC_UDR_SHIFT;
        else
                data = 1 << RTC_RBUDR_SHIFT;

        ret = regmap_update_bits(info->rtc_regmap,
                                 info->drv_data->map[REG_RTC_UPDATE0],
                                 data, data);
        if (ret < 0)
                dev_err(info->dev, "Fail to write update reg(ret=%d, data=0x%x)\n",
                        ret, data);
        else {
                /* Minimum delay required before RTC update. */
                usleep_range(delay, delay * 2);
        }

        return ret;
}

static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        u8 data[RTC_NR_TIME];
        int ret;

        mutex_lock(&info->lock);

        ret = max77686_rtc_update(info, MAX77686_RTC_READ);
        if (ret < 0)
                goto out;

        ret = regmap_bulk_read(info->rtc_regmap,
                               info->drv_data->map[REG_RTC_SEC],
                               data, ARRAY_SIZE(data));
        if (ret < 0) {
                dev_err(info->dev, "Fail to read time reg(%d)\n", ret);
                goto out;
        }

        max77686_rtc_data_to_tm(data, tm, info);

out:
        mutex_unlock(&info->lock);
        return ret;
}

static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        u8 data[RTC_NR_TIME];
        int ret;

        ret = max77686_rtc_tm_to_data(tm, data, info);
        if (ret < 0)
                return ret;

        mutex_lock(&info->lock);

        ret = regmap_bulk_write(info->rtc_regmap,
                                info->drv_data->map[REG_RTC_SEC],
                                data, ARRAY_SIZE(data));
        if (ret < 0) {
                dev_err(info->dev, "Fail to write time reg(%d)\n", ret);
                goto out;
        }

        ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);

out:
        mutex_unlock(&info->lock);
        return ret;
}

static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        u8 data[RTC_NR_TIME];
        unsigned int val;
        const unsigned int *map = info->drv_data->map;
        int i, ret;

        mutex_lock(&info->lock);

        ret = max77686_rtc_update(info, MAX77686_RTC_READ);
        if (ret < 0)
                goto out;

        ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
                               data, ARRAY_SIZE(data));
        if (ret < 0) {
                dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
                goto out;
        }

        max77686_rtc_data_to_tm(data, &alrm->time, info);

        alrm->enabled = 0;

        if (info->drv_data->alarm_enable_reg) {
                if (map[REG_RTC_AE1] == REG_RTC_NONE) {
                        ret = -EINVAL;
                        dev_err(info->dev,
                                "alarm enable register not set(%d)\n", ret);
                        goto out;
                }

                ret = regmap_read(info->rtc_regmap, map[REG_RTC_AE1], &val);
                if (ret < 0) {
                        dev_err(info->dev,
                                "fail to read alarm enable(%d)\n", ret);
                        goto out;
                }

                if (val)
                        alrm->enabled = 1;
        } else {
                for (i = 0; i < ARRAY_SIZE(data); i++) {
                        if (data[i] & ALARM_ENABLE_MASK) {
                                alrm->enabled = 1;
                                break;
                        }
                }
        }

        alrm->pending = 0;

        if (info->drv_data->alarm_pending_status_reg == MAX77686_INVALID_REG)
                goto out;

        ret = regmap_read(info->regmap,
                          info->drv_data->alarm_pending_status_reg, &val);
        if (ret < 0) {
                dev_err(info->dev,
                        "Fail to read alarm pending status reg(%d)\n", ret);
                goto out;
        }

        if (val & (1 << 4)) /* RTCA1 */
                alrm->pending = 1;

out:
        mutex_unlock(&info->lock);
        return ret;
}

static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
{
        u8 data[RTC_NR_TIME];
        int ret, i;
        struct rtc_time tm;
        const unsigned int *map = info->drv_data->map;

        if (!mutex_is_locked(&info->lock))
                dev_warn(info->dev, "%s: should have mutex locked\n", __func__);

        ret = max77686_rtc_update(info, MAX77686_RTC_READ);
        if (ret < 0)
                goto out;

        if (info->drv_data->alarm_enable_reg) {
                if (map[REG_RTC_AE1] == REG_RTC_NONE) {
                        ret = -EINVAL;
                        dev_err(info->dev,
                                "alarm enable register not set(%d)\n", ret);
                        goto out;
                }

                ret = regmap_write(info->rtc_regmap, map[REG_RTC_AE1], 0);
        } else {
                ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
                                       data, ARRAY_SIZE(data));
                if (ret < 0) {
                        dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
                        goto out;
                }

                max77686_rtc_data_to_tm(data, &tm, info);

                for (i = 0; i < ARRAY_SIZE(data); i++)
                        data[i] &= ~ALARM_ENABLE_MASK;

                ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
                                        data, ARRAY_SIZE(data));
        }

        if (ret < 0) {
                dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
                goto out;
        }

        ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
        return ret;
}

static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
{
        u8 data[RTC_NR_TIME];
        int ret;
        struct rtc_time tm;
        const unsigned int *map = info->drv_data->map;

        if (!mutex_is_locked(&info->lock))
                dev_warn(info->dev, "%s: should have mutex locked\n", __func__);

        ret = max77686_rtc_update(info, MAX77686_RTC_READ);
        if (ret < 0)
                goto out;

        if (info->drv_data->alarm_enable_reg) {
                ret = regmap_write(info->rtc_regmap, map[REG_RTC_AE1],
                                   MAX77802_ALARM_ENABLE_VALUE);
        } else {
                ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
                                       data, ARRAY_SIZE(data));
                if (ret < 0) {
                        dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
                        goto out;
                }

                max77686_rtc_data_to_tm(data, &tm, info);

                data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
                data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
                data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
                data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
                if (data[RTC_MONTH] & 0xf)
                        data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
                if (data[RTC_YEAR] & info->drv_data->mask)
                        data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
                if (data[RTC_MONTHDAY] & 0x1f)
                        data[RTC_MONTHDAY] |= (1 << ALARM_ENABLE_SHIFT);

                ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
                                        data, ARRAY_SIZE(data));
        }

        if (ret < 0) {
                dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
                goto out;
        }

        ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
        return ret;
}

static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        u8 data[RTC_NR_TIME];
        int ret;

        ret = max77686_rtc_tm_to_data(&alrm->time, data, info);
        if (ret < 0)
                return ret;

        mutex_lock(&info->lock);

        ret = max77686_rtc_stop_alarm(info);
        if (ret < 0)
                goto out;

        ret = regmap_bulk_write(info->rtc_regmap,
                                info->drv_data->map[REG_ALARM1_SEC],
                                data, ARRAY_SIZE(data));

        if (ret < 0) {
                dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
                goto out;
        }

        ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
        if (ret < 0)
                goto out;

        if (alrm->enabled)
                ret = max77686_rtc_start_alarm(info);
out:
        mutex_unlock(&info->lock);
        return ret;
}

static int max77686_rtc_alarm_irq_enable(struct device *dev,
                                         unsigned int enabled)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        int ret;

        mutex_lock(&info->lock);
        if (enabled)
                ret = max77686_rtc_start_alarm(info);
        else
                ret = max77686_rtc_stop_alarm(info);
        mutex_unlock(&info->lock);

        return ret;
}

static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
{
        struct max77686_rtc_info *info = data;

        dev_dbg(info->dev, "RTC alarm IRQ: %d\n", irq);

        rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);

        return IRQ_HANDLED;
}

static const struct rtc_class_ops max77686_rtc_ops = {
        .read_time = max77686_rtc_read_time,
        .set_time = max77686_rtc_set_time,
        .read_alarm = max77686_rtc_read_alarm,
        .set_alarm = max77686_rtc_set_alarm,
        .alarm_irq_enable = max77686_rtc_alarm_irq_enable,
};

static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
{
        u8 data[2];
        int ret;

        /* Set RTC control register : Binary mode, 24hour mdoe */
        data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
        data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);

        ret = regmap_bulk_write(info->rtc_regmap,
                                info->drv_data->map[REG_RTC_CONTROLM],
                                data, ARRAY_SIZE(data));
        if (ret < 0) {
                dev_err(info->dev, "Fail to write controlm reg(%d)\n", ret);
                return ret;
        }

        ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
        return ret;
}

static int max77686_init_rtc_regmap(struct max77686_rtc_info *info)
{
        struct device *parent = info->dev->parent;
        struct i2c_client *parent_i2c = to_i2c_client(parent);
        struct i2c_client *client;
        int ret;

        if (info->drv_data->rtc_irq_from_platform) {
                struct platform_device *pdev = to_platform_device(info->dev);

                info->rtc_irq = platform_get_irq(pdev, 0);
                if (info->rtc_irq < 0)
                        return info->rtc_irq;
        } else {
                info->rtc_irq =  parent_i2c->irq;
        }

        info->regmap = dev_get_regmap(parent, NULL);
        if (!info->regmap)
                return dev_err_probe(info->dev, -ENODEV,
                                     "Failed to get rtc regmap\n");

        if (info->drv_data->rtc_i2c_addr == MAX77686_INVALID_I2C_ADDR) {
                info->rtc_regmap = info->regmap;
                goto add_rtc_irq;
        }

        client = devm_i2c_new_dummy_device(info->dev, parent_i2c->adapter,
                                           info->drv_data->rtc_i2c_addr);
        if (IS_ERR(client))
                return dev_err_probe(info->dev, PTR_ERR(client),
                                     "Failed to allocate I2C device for RTC\n");

        info->rtc_regmap = devm_regmap_init_i2c(client,
                                                info->drv_data->regmap_config);
        if (IS_ERR(info->rtc_regmap))
                return dev_err_probe(info->dev, PTR_ERR(info->rtc_regmap),
                                     "Failed to allocate RTC regmap\n");

add_rtc_irq:
        ret = regmap_add_irq_chip(info->rtc_regmap, info->rtc_irq,
                                  IRQF_ONESHOT | IRQF_SHARED,
                                  0, info->drv_data->rtc_irq_chip,
                                  &info->rtc_irq_data);
        if (ret < 0)
                return dev_err_probe(info->dev, ret,
                                     "Failed to add RTC irq chip\n");

        return 0;
}

static int max77686_rtc_probe(struct platform_device *pdev)
{
        struct max77686_rtc_info *info;
        const struct platform_device_id *id = platform_get_device_id(pdev);
        int ret;

        info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
                            GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        mutex_init(&info->lock);
        info->dev = &pdev->dev;
        info->drv_data = (const struct max77686_rtc_driver_data *)
                id->driver_data;

        ret = max77686_init_rtc_regmap(info);
        if (ret < 0)
                return ret;

        platform_set_drvdata(pdev, info);

        ret = max77686_rtc_init_reg(info);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
                goto err_rtc;
        }

        device_init_wakeup(&pdev->dev, true);

        info->rtc_dev = devm_rtc_device_register(&pdev->dev, id->name,
                                        &max77686_rtc_ops, THIS_MODULE);

        if (IS_ERR(info->rtc_dev)) {
                ret = PTR_ERR(info->rtc_dev);
                dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
                if (ret == 0)
                        ret = -EINVAL;
                goto err_rtc;
        }

        info->virq = regmap_irq_get_virq(info->rtc_irq_data,
                                         MAX77686_RTCIRQ_RTCA1);
        if (info->virq <= 0) {
                ret = -ENXIO;
                goto err_rtc;
        }

        ret = request_threaded_irq(info->virq, NULL, max77686_rtc_alarm_irq, 0,
                                   "rtc-alarm1", info);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
                        info->virq, ret);
                goto err_rtc;
        }

        return 0;

err_rtc:
        regmap_del_irq_chip(info->rtc_irq, info->rtc_irq_data);

        return ret;
}

static void max77686_rtc_remove(struct platform_device *pdev)
{
        struct max77686_rtc_info *info = platform_get_drvdata(pdev);

        free_irq(info->virq, info);
        regmap_del_irq_chip(info->rtc_irq, info->rtc_irq_data);
}

#ifdef CONFIG_PM_SLEEP
static int max77686_rtc_suspend(struct device *dev)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);
        int ret = 0;

        if (device_may_wakeup(dev)) {
                struct max77686_rtc_info *info = dev_get_drvdata(dev);

                ret = enable_irq_wake(info->virq);
        }

        /*
         * If the main IRQ (not virtual) is the parent IRQ, then it must be
         * disabled during suspend because if it happens while suspended it
         * will be handled before resuming I2C.
         *
         * Since Main IRQ is shared, all its users should disable it to be sure
         * it won't fire while one of them is still suspended.
         */
        if (!info->drv_data->rtc_irq_from_platform)
                disable_irq(info->rtc_irq);

        return ret;
}

static int max77686_rtc_resume(struct device *dev)
{
        struct max77686_rtc_info *info = dev_get_drvdata(dev);

        if (!info->drv_data->rtc_irq_from_platform)
                enable_irq(info->rtc_irq);

        if (device_may_wakeup(dev)) {
                struct max77686_rtc_info *info = dev_get_drvdata(dev);

                return disable_irq_wake(info->virq);
        }

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
                         max77686_rtc_suspend, max77686_rtc_resume);

static const struct platform_device_id rtc_id[] = {
        { "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
        { "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data, },
        { "max77620-rtc", .driver_data = (kernel_ulong_t)&max77620_drv_data, },
        { "max77714-rtc", .driver_data = (kernel_ulong_t)&max77714_drv_data, },
        {},
};
MODULE_DEVICE_TABLE(platform, rtc_id);

static struct platform_driver max77686_rtc_driver = {
        .driver         = {
                .name   = "max77686-rtc",
                .pm     = &max77686_rtc_pm_ops,
        },
        .probe          = max77686_rtc_probe,
        .remove         = max77686_rtc_remove,
        .id_table       = rtc_id,
};

module_platform_driver(max77686_rtc_driver);

MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
MODULE_LICENSE("GPL");