/*
 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
 *
 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
 * Copyright (C) 2006 Tower Technologies
 * Copyright (C) 2008 Paul Mundt
 *
 * 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/i2c.h>
#include <linux/rtc.h>
#include <linux/bcd.h>

#define DRV_VERSION "0.6"


/*
 * Ricoh has a family of I2C based RTCs, which differ only slightly from
 * each other.  Differences center on pinout (e.g. how many interrupts,
 * output clock, etc) and how the control registers are used.  The '372
 * is significant only because that's the one this driver first supported.
 */
#define RS5C372_REG_SECS        0
#define RS5C372_REG_MINS        1
#define RS5C372_REG_HOURS       2
#define RS5C372_REG_WDAY        3
#define RS5C372_REG_DAY         4
#define RS5C372_REG_MONTH       5
#define RS5C372_REG_YEAR        6
#define RS5C372_REG_TRIM        7
#       define RS5C372_TRIM_XSL         0x80
#       define RS5C372_TRIM_MASK        0x7F

#define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
#define RS5C_REG_ALARM_A_HOURS  9
#define RS5C_REG_ALARM_A_WDAY   10

#define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
#define RS5C_REG_ALARM_B_HOURS  12
#define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */

#define RS5C_REG_CTRL1          14
#       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
#       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
#       define RV5C387_CTRL1_24         (1 << 5)
#       define RS5C372A_CTRL1_SL1       (1 << 5)
#       define RS5C_CTRL1_CT_MASK       (7 << 0)
#       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
#       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
#define RS5C_REG_CTRL2          15
#       define RS5C372_CTRL2_24         (1 << 5)
#       define R2025_CTRL2_XST          (1 << 5)
#       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
#       define RS5C_CTRL2_CTFG          (1 << 2)
#       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
#       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */


/* to read (style 1) or write registers starting at R */
#define RS5C_ADDR(R)            (((R) << 4) | 0)


enum rtc_type {
        rtc_undef = 0,
        rtc_r2025sd,
        rtc_rs5c372a,
        rtc_rs5c372b,
        rtc_rv5c386,
        rtc_rv5c387a,
};

static const struct i2c_device_id rs5c372_id[] = {
        { "r2025sd", rtc_r2025sd },
        { "rs5c372a", rtc_rs5c372a },
        { "rs5c372b", rtc_rs5c372b },
        { "rv5c386", rtc_rv5c386 },
        { "rv5c387a", rtc_rv5c387a },
        { }
};
MODULE_DEVICE_TABLE(i2c, rs5c372_id);

/* REVISIT:  this assumes that:
 *  - we're in the 21st century, so it's safe to ignore the century
 *    bit for rv5c38[67] (REG_MONTH bit 7);
 *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
 */
struct rs5c372 {
        struct i2c_client       *client;
        struct rtc_device       *rtc;
        enum rtc_type           type;
        unsigned                time24:1;
        unsigned                has_irq:1;
        unsigned                smbus:1;
        char                    buf[17];
        char                    *regs;
};

static int rs5c_get_regs(struct rs5c372 *rs5c)
{
        struct i2c_client       *client = rs5c->client;
        struct i2c_msg          msgs[] = {
                { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
        };

        /* This implements the third reading method from the datasheet, using
         * an internal address that's reset after each transaction (by STOP)
         * to 0x0f ... so we read extra registers, and skip the first one.
         *
         * The first method doesn't work with the iop3xx adapter driver, on at
         * least 80219 chips; this works around that bug.
         *
         * The third method on the other hand doesn't work for the SMBus-only
         * configurations, so we use the the first method there, stripping off
         * the extra register in the process.
         */
        if (rs5c->smbus) {
                int addr = RS5C_ADDR(RS5C372_REG_SECS);
                int size = sizeof(rs5c->buf) - 1;

                if (i2c_smbus_read_i2c_block_data(client, addr, size,
                                                  rs5c->buf + 1) != size) {
                        dev_warn(&client->dev, "can't read registers\n");
                        return -EIO;
                }
        } else {
                if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
                        dev_warn(&client->dev, "can't read registers\n");
                        return -EIO;
                }
        }

        dev_dbg(&client->dev,
                "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
                "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
                rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
                rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
                rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
                rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);

        return 0;
}

static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
{
        unsigned        hour;

        if (rs5c->time24)
                return bcd2bin(reg & 0x3f);

        hour = bcd2bin(reg & 0x1f);
        if (hour == 12)
                hour = 0;
        if (reg & 0x20)
                hour += 12;
        return hour;
}

static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
{
        if (rs5c->time24)
                return bin2bcd(hour);

        if (hour > 12)
                return 0x20 | bin2bcd(hour - 12);
        if (hour == 12)
                return 0x20 | bin2bcd(12);
        if (hour == 0)
                return bin2bcd(12);
        return bin2bcd(hour);
}

static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
        struct rs5c372  *rs5c = i2c_get_clientdata(client);
        int             status = rs5c_get_regs(rs5c);

        if (status < 0)
                return status;

        tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
        tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
        tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);

        tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
        tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);

        /* tm->tm_mon is zero-based */
        tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;

        /* year is 1900 + tm->tm_year */
        tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;

        dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

        /* rtc might need initialization */
        return rtc_valid_tm(tm);
}

static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
        struct rs5c372  *rs5c = i2c_get_clientdata(client);
        unsigned char   buf[8];
        int             addr;

        dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

        addr   = RS5C_ADDR(RS5C372_REG_SECS);
        buf[0] = bin2bcd(tm->tm_sec);
        buf[1] = bin2bcd(tm->tm_min);
        buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
        buf[3] = bin2bcd(tm->tm_wday);
        buf[4] = bin2bcd(tm->tm_mday);
        buf[5] = bin2bcd(tm->tm_mon + 1);
        buf[6] = bin2bcd(tm->tm_year - 100);

        if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
                dev_err(&client->dev, "%s: write error\n", __func__);
                return -EIO;
        }

        return 0;
}

#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
#define NEED_TRIM
#endif

#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
#define NEED_TRIM
#endif

#ifdef  NEED_TRIM
static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
{
        struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
        u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];

        if (osc)
                *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;

        if (trim) {
                dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
                tmp &= RS5C372_TRIM_MASK;
                if (tmp & 0x3e) {
                        int t = tmp & 0x3f;

                        if (tmp & 0x40)
                                t = (~t | (s8)0xc0) + 1;
                        else
                                t = t - 1;

                        tmp = t * 2;
                } else
                        tmp = 0;
                *trim = tmp;
        }

        return 0;
}
#endif

static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
        return rs5c372_get_datetime(to_i2c_client(dev), tm);
}

static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
        return rs5c372_set_datetime(to_i2c_client(dev), tm);
}

#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)

static int
rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
        struct i2c_client       *client = to_i2c_client(dev);
        struct rs5c372          *rs5c = i2c_get_clientdata(client);
        unsigned char           buf;
        int                     status, addr;

        buf = rs5c->regs[RS5C_REG_CTRL1];
        switch (cmd) {
        case RTC_UIE_OFF:
        case RTC_UIE_ON:
                /* some 327a modes use a different IRQ pin for 1Hz irqs */
                if (rs5c->type == rtc_rs5c372a
                                && (buf & RS5C372A_CTRL1_SL1))
                        return -ENOIOCTLCMD;
        case RTC_AIE_OFF:
        case RTC_AIE_ON:
                /* these irq management calls only make sense for chips
                 * which are wired up to an IRQ.
                 */
                if (!rs5c->has_irq)
                        return -ENOIOCTLCMD;
                break;
        default:
                return -ENOIOCTLCMD;
        }

        status = rs5c_get_regs(rs5c);
        if (status < 0)
                return status;

        addr = RS5C_ADDR(RS5C_REG_CTRL1);
        switch (cmd) {
        case RTC_AIE_OFF:       /* alarm off */
                buf &= ~RS5C_CTRL1_AALE;
                break;
        case RTC_AIE_ON:        /* alarm on */
                buf |= RS5C_CTRL1_AALE;
                break;
        case RTC_UIE_OFF:       /* update off */
                buf &= ~RS5C_CTRL1_CT_MASK;
                break;
        case RTC_UIE_ON:        /* update on */
                buf &= ~RS5C_CTRL1_CT_MASK;
                buf |= RS5C_CTRL1_CT4;
                break;
        }

        if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
                printk(KERN_WARNING "%s: can't update alarm\n",
                        rs5c->rtc->name);
                status = -EIO;
        } else
                rs5c->regs[RS5C_REG_CTRL1] = buf;

        return status;
}

#else
#define rs5c_rtc_ioctl  NULL
#endif


/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 * which only exposes a polled programming interface; and since
 * these calls map directly to those EFI requests; we don't demand
 * we have an IRQ for this chip when we go through this API.
 *
 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 * though, managed through RTC_AIE_{ON,OFF} requests.
 */

static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
        struct i2c_client       *client = to_i2c_client(dev);
        struct rs5c372          *rs5c = i2c_get_clientdata(client);
        int                     status;

        status = rs5c_get_regs(rs5c);
        if (status < 0)
                return status;

        /* report alarm time */
        t->time.tm_sec = 0;
        t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
        t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
        t->time.tm_mday = -1;
        t->time.tm_mon = -1;
        t->time.tm_year = -1;
        t->time.tm_wday = -1;
        t->time.tm_yday = -1;
        t->time.tm_isdst = -1;

        /* ... and status */
        t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
        t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);

        return 0;
}

static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
        struct i2c_client       *client = to_i2c_client(dev);
        struct rs5c372          *rs5c = i2c_get_clientdata(client);
        int                     status, addr, i;
        unsigned char           buf[3];

        /* only handle up to 24 hours in the future, like RTC_ALM_SET */
        if (t->time.tm_mday != -1
                        || t->time.tm_mon != -1
                        || t->time.tm_year != -1)
                return -EINVAL;

        /* REVISIT: round up tm_sec */

        /* if needed, disable irq (clears pending status) */
        status = rs5c_get_regs(rs5c);
        if (status < 0)
                return status;
        if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
                addr = RS5C_ADDR(RS5C_REG_CTRL1);
                buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
                if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
                        pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
                        return -EIO;
                }
                rs5c->regs[RS5C_REG_CTRL1] = buf[0];
        }

        /* set alarm */
        buf[0] = bin2bcd(t->time.tm_min);
        buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
        buf[2] = 0x7f;  /* any/all days */

        for (i = 0; i < sizeof(buf); i++) {
                addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
                if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
                        pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
                        return -EIO;
                }
        }

        /* ... and maybe enable its irq */
        if (t->enabled) {
                addr = RS5C_ADDR(RS5C_REG_CTRL1);
                buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
                if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
                        printk(KERN_WARNING "%s: can't enable alarm\n",
                                rs5c->rtc->name);
                rs5c->regs[RS5C_REG_CTRL1] = buf[0];
        }

        return 0;
}

#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)

static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
{
        int err, osc, trim;

        err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
        if (err == 0) {
                seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
                                osc / 1000, osc % 1000);
                seq_printf(seq, "trim\t\t: %d\n", trim);
        }

        return 0;
}

#else
#define rs5c372_rtc_proc        NULL
#endif

static const struct rtc_class_ops rs5c372_rtc_ops = {
        .proc           = rs5c372_rtc_proc,
        .ioctl          = rs5c_rtc_ioctl,
        .read_time      = rs5c372_rtc_read_time,
        .set_time       = rs5c372_rtc_set_time,
        .read_alarm     = rs5c_read_alarm,
        .set_alarm      = rs5c_set_alarm,
};

#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)

static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int err, trim;

        err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
        if (err)
                return err;

        return sprintf(buf, "%d\n", trim);
}
static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);

static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int err, osc;

        err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
        if (err)
                return err;

        return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
}
static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);

static int rs5c_sysfs_register(struct device *dev)
{
        int err;

        err = device_create_file(dev, &dev_attr_trim);
        if (err)
                return err;
        err = device_create_file(dev, &dev_attr_osc);
        if (err)
                device_remove_file(dev, &dev_attr_trim);

        return err;
}

static void rs5c_sysfs_unregister(struct device *dev)
{
        device_remove_file(dev, &dev_attr_trim);
        device_remove_file(dev, &dev_attr_osc);
}

#else
static int rs5c_sysfs_register(struct device *dev)
{
        return 0;
}

static void rs5c_sysfs_unregister(struct device *dev)
{
        /* nothing */
}
#endif  /* SYSFS */

static struct i2c_driver rs5c372_driver;

static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
{
        unsigned char buf[2];
        int addr, i, ret = 0;

        if (rs5c372->type == rtc_r2025sd) {
                if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
                        return ret;
                rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
        } else {
                if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
                        return ret;
                rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
        }

        addr   = RS5C_ADDR(RS5C_REG_CTRL1);
        buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
        buf[1] = rs5c372->regs[RS5C_REG_CTRL2];

        /* use 24hr mode */
        switch (rs5c372->type) {
        case rtc_rs5c372a:
        case rtc_rs5c372b:
                buf[1] |= RS5C372_CTRL2_24;
                rs5c372->time24 = 1;
                break;
        case rtc_r2025sd:
        case rtc_rv5c386:
        case rtc_rv5c387a:
                buf[0] |= RV5C387_CTRL1_24;
                rs5c372->time24 = 1;
                break;
        default:
                /* impossible */
                break;
        }

        for (i = 0; i < sizeof(buf); i++) {
                addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
                ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
                if (unlikely(ret < 0))
                        return ret;
        }

        rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
        rs5c372->regs[RS5C_REG_CTRL2] = buf[1];

        return 0;
}

static int rs5c372_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
{
        int err = 0;
        int smbus_mode = 0;
        struct rs5c372 *rs5c372;
        struct rtc_time tm;

        dev_dbg(&client->dev, "%s\n", __func__);

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
                        I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
                /*
                 * If we don't have any master mode adapter, try breaking
                 * it down in to the barest of capabilities.
                 */
                if (i2c_check_functionality(client->adapter,
                                I2C_FUNC_SMBUS_BYTE_DATA |
                                I2C_FUNC_SMBUS_I2C_BLOCK))
                        smbus_mode = 1;
                else {
                        /* Still no good, give up */
                        err = -ENODEV;
                        goto exit;
                }
        }

        if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
                err = -ENOMEM;
                goto exit;
        }

        rs5c372->client = client;
        i2c_set_clientdata(client, rs5c372);
        rs5c372->type = id->driver_data;

        /* we read registers 0x0f then 0x00-0x0f; skip the first one */
        rs5c372->regs = &rs5c372->buf[1];
        rs5c372->smbus = smbus_mode;

        err = rs5c_get_regs(rs5c372);
        if (err < 0)
                goto exit_kfree;

        /* clock may be set for am/pm or 24 hr time */
        switch (rs5c372->type) {
        case rtc_rs5c372a:
        case rtc_rs5c372b:
                /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
                 * so does periodic irq, except some 327a modes.
                 */
                if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
                        rs5c372->time24 = 1;
                break;
        case rtc_r2025sd:
        case rtc_rv5c386:
        case rtc_rv5c387a:
                if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
                        rs5c372->time24 = 1;
                /* alarm uses ALARM_W; and nINTRB for alarm and periodic
                 * irq, on both 386 and 387
                 */
                break;
        default:
                dev_err(&client->dev, "unknown RTC type\n");
                goto exit_kfree;
        }

        /* if the oscillator lost power and no other software (like
         * the bootloader) set it up, do it here.
         *
         * The R2025S/D does this a little differently than the other
         * parts, so we special case that..
         */
        err = rs5c_oscillator_setup(rs5c372);
        if (unlikely(err < 0)) {
                dev_err(&client->dev, "setup error\n");
                goto exit_kfree;
        }

        if (rs5c372_get_datetime(client, &tm) < 0)
                dev_warn(&client->dev, "clock needs to be set\n");

        dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
                        ({ char *s; switch (rs5c372->type) {
                        case rtc_r2025sd:       s = "r2025sd"; break;
                        case rtc_rs5c372a:      s = "rs5c372a"; break;
                        case rtc_rs5c372b:      s = "rs5c372b"; break;
                        case rtc_rv5c386:       s = "rv5c386"; break;
                        case rtc_rv5c387a:      s = "rv5c387a"; break;
                        default:                s = "chip"; break;
                        }; s;}),
                        rs5c372->time24 ? "24hr" : "am/pm"
                        );

        /* REVISIT use client->irq to register alarm irq ... */

        rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
                                &client->dev, &rs5c372_rtc_ops, THIS_MODULE);

        if (IS_ERR(rs5c372->rtc)) {
                err = PTR_ERR(rs5c372->rtc);
                goto exit_kfree;
        }

        err = rs5c_sysfs_register(&client->dev);
        if (err)
                goto exit_devreg;

        return 0;

exit_devreg:
        rtc_device_unregister(rs5c372->rtc);

exit_kfree:
        kfree(rs5c372);

exit:
        return err;
}

static int rs5c372_remove(struct i2c_client *client)
{
        struct rs5c372 *rs5c372 = i2c_get_clientdata(client);

        rtc_device_unregister(rs5c372->rtc);
        rs5c_sysfs_unregister(&client->dev);
        kfree(rs5c372);
        return 0;
}

static struct i2c_driver rs5c372_driver = {
        .driver         = {
                .name   = "rtc-rs5c372",
        },
        .probe          = rs5c372_probe,
        .remove         = rs5c372_remove,
        .id_table       = rs5c372_id,
};

static __init int rs5c372_init(void)
{
        return i2c_add_driver(&rs5c372_driver);
}

static __exit void rs5c372_exit(void)
{
        i2c_del_driver(&rs5c372_driver);
}

module_init(rs5c372_init);
module_exit(rs5c372_exit);

MODULE_AUTHOR(
                "Pavel Mironchik <pmironchik@optifacio.net>, "
                "Alessandro Zummo <a.zummo@towertech.it>, "
                "Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);