Add hard_irq_disable()

[linux-2.6.22.y-op.git] / drivers / rtc / rtc-cmos.c

/*
 * RTC class driver for "CMOS RTC":  PCs, ACPI, etc
 *
 * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
 * Copyright (C) 2006 David Brownell (convert to new framework)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

/*
 * The original "cmos clock" chip was an MC146818 chip, now obsolete.
 * That defined the register interface now provided by all PCs, some
 * non-PC systems, and incorporated into ACPI.  Modern PC chipsets
 * integrate an MC146818 clone in their southbridge, and boards use
 * that instead of discrete clones like the DS12887 or M48T86.  There
 * are also clones that connect using the LPC bus.
 *
 * That register API is also used directly by various other drivers
 * (notably for integrated NVRAM), infrastructure (x86 has code to
 * bypass the RTC framework, directly reading the RTC during boot
 * and updating minutes/seconds for systems using NTP synch) and
 * utilities (like userspace 'hwclock', if no /dev node exists).
 *
 * So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
 * interrupts disabled, holding the global rtc_lock, to exclude those
 * other drivers and utilities on correctly configured systems.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>

/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
#include <asm-generic/rtc.h>


struct cmos_rtc {
        struct rtc_device       *rtc;
        struct device           *dev;
        int                     irq;
        struct resource         *iomem;

        void                    (*wake_on)(struct device *);
        void                    (*wake_off)(struct device *);

        u8                      enabled_wake;
        u8                      suspend_ctrl;

        /* newer hardware extends the original register set */
        u8                      day_alrm;
        u8                      mon_alrm;
        u8                      century;
};

/* both platform and pnp busses use negative numbers for invalid irqs */
#define is_valid_irq(n)         ((n) >= 0)

static const char driver_name[] = "rtc_cmos";

/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
 * always mask it against the irq enable bits in RTC_CONTROL.  Bit values
 * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
 */
#define RTC_IRQMASK     (RTC_PF | RTC_AF | RTC_UF)

static inline int is_intr(u8 rtc_intr)
{
        if (!(rtc_intr & RTC_IRQF))
                return 0;
        return rtc_intr & RTC_IRQMASK;
}

/*----------------------------------------------------------------*/

static int cmos_read_time(struct device *dev, struct rtc_time *t)
{
        /* REVISIT:  if the clock has a "century" register, use
         * that instead of the heuristic in get_rtc_time().
         * That'll make Y3K compatility (year > 2070) easy!
         */
        get_rtc_time(t);
        return 0;
}

static int cmos_set_time(struct device *dev, struct rtc_time *t)
{
        /* REVISIT:  set the "century" register if available
         *
         * NOTE: this ignores the issue whereby updating the seconds
         * takes effect exactly 500ms after we write the register.
         * (Also queueing and other delays before we get this far.)
         */
        return set_rtc_time(t);
}

static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char   rtc_control;

        if (!is_valid_irq(cmos->irq))
                return -EIO;

        /* Basic alarms only support hour, minute, and seconds fields.
         * Some also support day and month, for alarms up to a year in
         * the future.
         */
        t->time.tm_mday = -1;
        t->time.tm_mon = -1;

        spin_lock_irq(&rtc_lock);
        t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
        t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
        t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);

        if (cmos->day_alrm) {
                t->time.tm_mday = CMOS_READ(cmos->day_alrm);
                if (!t->time.tm_mday)
                        t->time.tm_mday = -1;

                if (cmos->mon_alrm) {
                        t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
                        if (!t->time.tm_mon)
                                t->time.tm_mon = -1;
                }
        }

        rtc_control = CMOS_READ(RTC_CONTROL);
        spin_unlock_irq(&rtc_lock);

        /* REVISIT this assumes PC style usage:  always BCD */

        if (((unsigned)t->time.tm_sec) < 0x60)
                t->time.tm_sec = BCD2BIN(t->time.tm_sec);
        else
                t->time.tm_sec = -1;
        if (((unsigned)t->time.tm_min) < 0x60)
                t->time.tm_min = BCD2BIN(t->time.tm_min);
        else
                t->time.tm_min = -1;
        if (((unsigned)t->time.tm_hour) < 0x24)
                t->time.tm_hour = BCD2BIN(t->time.tm_hour);
        else
                t->time.tm_hour = -1;

        if (cmos->day_alrm) {
                if (((unsigned)t->time.tm_mday) <= 0x31)
                        t->time.tm_mday = BCD2BIN(t->time.tm_mday);
                else
                        t->time.tm_mday = -1;
                if (cmos->mon_alrm) {
                        if (((unsigned)t->time.tm_mon) <= 0x12)
                                t->time.tm_mon = BCD2BIN(t->time.tm_mon) - 1;
                        else
                                t->time.tm_mon = -1;
                }
        }
        t->time.tm_year = -1;

        t->enabled = !!(rtc_control & RTC_AIE);
        t->pending = 0;

        return 0;
}

static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char   mon, mday, hrs, min, sec;
        unsigned char   rtc_control, rtc_intr;

        if (!is_valid_irq(cmos->irq))
                return -EIO;

        /* REVISIT this assumes PC style usage:  always BCD */

        /* Writing 0xff means "don't care" or "match all".  */

        mon = t->time.tm_mon;
        mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
        mon++;

        mday = t->time.tm_mday;
        mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;

        hrs = t->time.tm_hour;
        hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;

        min = t->time.tm_min;
        min = (min < 60) ? BIN2BCD(min) : 0xff;

        sec = t->time.tm_sec;
        sec = (sec < 60) ? BIN2BCD(sec) : 0xff;

        spin_lock_irq(&rtc_lock);

        /* next rtc irq must not be from previous alarm setting */
        rtc_control = CMOS_READ(RTC_CONTROL);
        rtc_control &= ~RTC_AIE;
        CMOS_WRITE(rtc_control, RTC_CONTROL);
        rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
        rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
        if (is_intr(rtc_intr))
                rtc_update_irq(cmos->rtc, 1, rtc_intr);

        /* update alarm */
        CMOS_WRITE(hrs, RTC_HOURS_ALARM);
        CMOS_WRITE(min, RTC_MINUTES_ALARM);
        CMOS_WRITE(sec, RTC_SECONDS_ALARM);

        /* the system may support an "enhanced" alarm */
        if (cmos->day_alrm) {
                CMOS_WRITE(mday, cmos->day_alrm);
                if (cmos->mon_alrm)
                        CMOS_WRITE(mon, cmos->mon_alrm);
        }

        if (t->enabled) {
                rtc_control |= RTC_AIE;
                CMOS_WRITE(rtc_control, RTC_CONTROL);
                rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
                rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
                if (is_intr(rtc_intr))
                        rtc_update_irq(cmos->rtc, 1, rtc_intr);
        }

        spin_unlock_irq(&rtc_lock);

        return 0;
}

static int cmos_set_freq(struct device *dev, int freq)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        int             f;
        unsigned long   flags;

        if (!is_valid_irq(cmos->irq))
                return -ENXIO;

        /* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
        f = ffs(freq);
        if (f != 0) {
                if (f-- > 16 || freq != (1 << f))
                        return -EINVAL;
                f = 16 - f;
        }

        spin_lock_irqsave(&rtc_lock, flags);
        CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
        spin_unlock_irqrestore(&rtc_lock, flags);

        return 0;
}

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

static int
cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char   rtc_control, rtc_intr;
        unsigned long   flags;

        switch (cmd) {
        case RTC_AIE_OFF:
        case RTC_AIE_ON:
        case RTC_UIE_OFF:
        case RTC_UIE_ON:
        case RTC_PIE_OFF:
        case RTC_PIE_ON:
                if (!is_valid_irq(cmos->irq))
                        return -EINVAL;
                break;
        default:
                return -ENOIOCTLCMD;
        }

        spin_lock_irqsave(&rtc_lock, flags);
        rtc_control = CMOS_READ(RTC_CONTROL);
        switch (cmd) {
        case RTC_AIE_OFF:       /* alarm off */
                rtc_control &= ~RTC_AIE;
                break;
        case RTC_AIE_ON:        /* alarm on */
                rtc_control |= RTC_AIE;
                break;
        case RTC_UIE_OFF:       /* update off */
                rtc_control &= ~RTC_UIE;
                break;
        case RTC_UIE_ON:        /* update on */
                rtc_control |= RTC_UIE;
                break;
        case RTC_PIE_OFF:       /* periodic off */
                rtc_control &= ~RTC_PIE;
                break;
        case RTC_PIE_ON:        /* periodic on */
                rtc_control |= RTC_PIE;
                break;
        }
        CMOS_WRITE(rtc_control, RTC_CONTROL);
        rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
        rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
        if (is_intr(rtc_intr))
                rtc_update_irq(cmos->rtc, 1, rtc_intr);
        spin_unlock_irqrestore(&rtc_lock, flags);
        return 0;
}

#else
#define cmos_rtc_ioctl  NULL
#endif

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

static int cmos_procfs(struct device *dev, struct seq_file *seq)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char   rtc_control, valid;

        spin_lock_irq(&rtc_lock);
        rtc_control = CMOS_READ(RTC_CONTROL);
        valid = CMOS_READ(RTC_VALID);
        spin_unlock_irq(&rtc_lock);

        /* NOTE:  at least ICH6 reports battery status using a different
         * (non-RTC) bit; and SQWE is ignored on many current systems.
         */
        return seq_printf(seq,
                        "periodic_IRQ\t: %s\n"
                        "update_IRQ\t: %s\n"
                        // "square_wave\t: %s\n"
                        // "BCD\t\t: %s\n"
                        "DST_enable\t: %s\n"
                        "periodic_freq\t: %d\n"
                        "batt_status\t: %s\n",
                        (rtc_control & RTC_PIE) ? "yes" : "no",
                        (rtc_control & RTC_UIE) ? "yes" : "no",
                        // (rtc_control & RTC_SQWE) ? "yes" : "no",
                        // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
                        (rtc_control & RTC_DST_EN) ? "yes" : "no",
                        cmos->rtc->irq_freq,
                        (valid & RTC_VRT) ? "okay" : "dead");
}

#else
#define cmos_procfs     NULL
#endif

static const struct rtc_class_ops cmos_rtc_ops = {
        .ioctl          = cmos_rtc_ioctl,
        .read_time      = cmos_read_time,
        .set_time       = cmos_set_time,
        .read_alarm     = cmos_read_alarm,
        .set_alarm      = cmos_set_alarm,
        .proc           = cmos_procfs,
        .irq_set_freq   = cmos_set_freq,
};

/*----------------------------------------------------------------*/

static struct cmos_rtc  cmos_rtc;

static irqreturn_t cmos_interrupt(int irq, void *p)
{
        u8              irqstat;

        spin_lock(&rtc_lock);
        irqstat = CMOS_READ(RTC_INTR_FLAGS);
        irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
        spin_unlock(&rtc_lock);

        if (is_intr(irqstat)) {
                rtc_update_irq(p, 1, irqstat);
                return IRQ_HANDLED;
        } else
                return IRQ_NONE;
}

#ifdef  CONFIG_PNP
#define is_pnp()        1
#define INITSECTION

#else
#define is_pnp()        0
#define INITSECTION     __init
#endif

static int INITSECTION
cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
{
        struct cmos_rtc_board_info      *info = dev->platform_data;
        int                             retval = 0;
        unsigned char                   rtc_control;

        /* there can be only one ... */
        if (cmos_rtc.dev)
                return -EBUSY;

        if (!ports)
                return -ENODEV;

        cmos_rtc.irq = rtc_irq;
        cmos_rtc.iomem = ports;

        /* For ACPI systems extension info comes from the FADT.  On others,
         * board specific setup provides it as appropriate.  Systems where
         * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
         * some almost-clones) can provide hooks to make that behave.
         */
        if (info) {
                cmos_rtc.day_alrm = info->rtc_day_alarm;
                cmos_rtc.mon_alrm = info->rtc_mon_alarm;
                cmos_rtc.century = info->rtc_century;

                if (info->wake_on && info->wake_off) {
                        cmos_rtc.wake_on = info->wake_on;
                        cmos_rtc.wake_off = info->wake_off;
                }
        }

        cmos_rtc.rtc = rtc_device_register(driver_name, dev,
                                &cmos_rtc_ops, THIS_MODULE);
        if (IS_ERR(cmos_rtc.rtc))
                return PTR_ERR(cmos_rtc.rtc);

        cmos_rtc.dev = dev;
        dev_set_drvdata(dev, &cmos_rtc);

        /* platform and pnp busses handle resources incompatibly.
         *
         * REVISIT for non-x86 systems we may need to handle io memory
         * resources: ioremap them, and request_mem_region().
         */
        if (is_pnp()) {
                retval = request_resource(&ioport_resource, ports);
                if (retval < 0) {
                        dev_dbg(dev, "i/o registers already in use\n");
                        goto cleanup0;
                }
        }
        rename_region(ports, cmos_rtc.rtc->dev.bus_id);

        spin_lock_irq(&rtc_lock);

        /* force periodic irq to CMOS reset default of 1024Hz;
         *
         * REVISIT it's been reported that at least one x86_64 ALI mobo
         * doesn't use 32KHz here ... for portability we might need to
         * do something about other clock frequencies.
         */
        CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
        cmos_rtc.rtc->irq_freq = 1024;

        /* disable irqs.
         *
         * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
         * allegedly some older rtcs need that to handle irqs properly
         */
        rtc_control = CMOS_READ(RTC_CONTROL);
        rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
        CMOS_WRITE(rtc_control, RTC_CONTROL);
        CMOS_READ(RTC_INTR_FLAGS);

        spin_unlock_irq(&rtc_lock);

        /* FIXME teach the alarm code how to handle binary mode;
         * <asm-generic/rtc.h> doesn't know 12-hour mode either.
         */
        if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
                dev_dbg(dev, "only 24-hr BCD mode supported\n");
                retval = -ENXIO;
                goto cleanup1;
        }

        if (is_valid_irq(rtc_irq))
                retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
                                cmos_rtc.rtc->dev.bus_id,
                                cmos_rtc.rtc);
        if (retval < 0) {
                dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
                goto cleanup1;
        }

        /* REVISIT optionally make 50 or 114 bytes NVRAM available,
         * like rtc-ds1553, rtc-ds1742 ... this will often include
         * registers for century, and day/month alarm.
         */

        pr_info("%s: alarms up to one %s%s\n",
                        cmos_rtc.rtc->dev.bus_id,
                        is_valid_irq(rtc_irq)
                                ?  (cmos_rtc.mon_alrm
                                        ? "year"
                                        : (cmos_rtc.day_alrm
                                                ? "month" : "day"))
                                : "no",
                        cmos_rtc.century ? ", y3k" : ""
                        );

        return 0;

cleanup1:
        rename_region(ports, NULL);
cleanup0:
        rtc_device_unregister(cmos_rtc.rtc);
        return retval;
}

static void cmos_do_shutdown(void)
{
        unsigned char   rtc_control;

        spin_lock_irq(&rtc_lock);
        rtc_control = CMOS_READ(RTC_CONTROL);
        rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
        CMOS_WRITE(rtc_control, RTC_CONTROL);
        CMOS_READ(RTC_INTR_FLAGS);
        spin_unlock_irq(&rtc_lock);
}

static void __exit cmos_do_remove(struct device *dev)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);

        cmos_do_shutdown();

        if (is_pnp())
                release_resource(cmos->iomem);
        rename_region(cmos->iomem, NULL);

        if (is_valid_irq(cmos->irq))
                free_irq(cmos->irq, cmos_rtc.rtc);

        rtc_device_unregister(cmos_rtc.rtc);

        cmos_rtc.dev = NULL;
        dev_set_drvdata(dev, NULL);
}

#ifdef  CONFIG_PM

static int cmos_suspend(struct device *dev, pm_message_t mesg)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        int             do_wake = device_may_wakeup(dev);
        unsigned char   tmp;

        /* only the alarm might be a wakeup event source */
        spin_lock_irq(&rtc_lock);
        cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
        if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
                unsigned char   irqstat;

                if (do_wake)
                        tmp &= ~(RTC_PIE|RTC_UIE);
                else
                        tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
                CMOS_WRITE(tmp, RTC_CONTROL);
                irqstat = CMOS_READ(RTC_INTR_FLAGS);
                irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
                if (is_intr(irqstat))
                        rtc_update_irq(cmos->rtc, 1, irqstat);
        }
        spin_unlock_irq(&rtc_lock);

        if (tmp & RTC_AIE) {
                cmos->enabled_wake = 1;
                if (cmos->wake_on)
                        cmos->wake_on(dev);
                else
                        enable_irq_wake(cmos->irq);
        }

        pr_debug("%s: suspend%s, ctrl %02x\n",
                        cmos_rtc.rtc->dev.bus_id,
                        (tmp & RTC_AIE) ? ", alarm may wake" : "",
                        tmp);

        return 0;
}

static int cmos_resume(struct device *dev)
{
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char   tmp = cmos->suspend_ctrl;

        /* re-enable any irqs previously active */
        if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {

                if (cmos->enabled_wake) {
                        if (cmos->wake_off)
                                cmos->wake_off(dev);
                        else
                                disable_irq_wake(cmos->irq);
                        cmos->enabled_wake = 0;
                }

                spin_lock_irq(&rtc_lock);
                CMOS_WRITE(tmp, RTC_CONTROL);
                tmp = CMOS_READ(RTC_INTR_FLAGS);
                tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
                if (is_intr(tmp))
                        rtc_update_irq(cmos->rtc, 1, tmp);
                spin_unlock_irq(&rtc_lock);
        }

        pr_debug("%s: resume, ctrl %02x\n",
                        cmos_rtc.rtc->dev.bus_id,
                        cmos->suspend_ctrl);


        return 0;
}

#else
#define cmos_suspend    NULL
#define cmos_resume     NULL
#endif

/*----------------------------------------------------------------*/

/* The "CMOS" RTC normally lives on the platform_bus.  On ACPI systems,
 * the device node will always be created as a PNPACPI device.
 */

#ifdef  CONFIG_PNP

#include <linux/pnp.h>

static int __devinit
cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
{
        /* REVISIT paranoia argues for a shutdown notifier, since PNP
         * drivers can't provide shutdown() methods to disable IRQs.
         * Or better yet, fix PNP to allow those methods...
         */
        return cmos_do_probe(&pnp->dev,
                        &pnp->res.port_resource[0],
                        pnp->res.irq_resource[0].start);
}

static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
{
        cmos_do_remove(&pnp->dev);
}

#ifdef  CONFIG_PM

static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
{
        return cmos_suspend(&pnp->dev, mesg);
}

static int cmos_pnp_resume(struct pnp_dev *pnp)
{
        return cmos_resume(&pnp->dev);
}

#else
#define cmos_pnp_suspend        NULL
#define cmos_pnp_resume         NULL
#endif


static const struct pnp_device_id rtc_ids[] = {
        { .id = "PNP0b00", },
        { .id = "PNP0b01", },
        { .id = "PNP0b02", },
        { },
};
MODULE_DEVICE_TABLE(pnp, rtc_ids);

static struct pnp_driver cmos_pnp_driver = {
        .name           = (char *) driver_name,
        .id_table       = rtc_ids,
        .probe          = cmos_pnp_probe,
        .remove         = __exit_p(cmos_pnp_remove),

        /* flag ensures resume() gets called, and stops syslog spam */
        .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
        .suspend        = cmos_pnp_suspend,
        .resume         = cmos_pnp_resume,
};

static int __init cmos_init(void)
{
        return pnp_register_driver(&cmos_pnp_driver);
}
module_init(cmos_init);

static void __exit cmos_exit(void)
{
        pnp_unregister_driver(&cmos_pnp_driver);
}
module_exit(cmos_exit);

#else   /* no PNP */

/*----------------------------------------------------------------*/

/* Platform setup should have set up an RTC device, when PNP is
 * unavailable ... this could happen even on (older) PCs.
 */

static int __init cmos_platform_probe(struct platform_device *pdev)
{
        return cmos_do_probe(&pdev->dev,
                        platform_get_resource(pdev, IORESOURCE_IO, 0),
                        platform_get_irq(pdev, 0));
}

static int __exit cmos_platform_remove(struct platform_device *pdev)
{
        cmos_do_remove(&pdev->dev);
        return 0;
}

static void cmos_platform_shutdown(struct platform_device *pdev)
{
        cmos_do_shutdown();
}

static struct platform_driver cmos_platform_driver = {
        .remove         = __exit_p(cmos_platform_remove),
        .shutdown       = cmos_platform_shutdown,
        .driver = {
                .name           = (char *) driver_name,
                .suspend        = cmos_suspend,
                .resume         = cmos_resume,
        }
};

static int __init cmos_init(void)
{
        return platform_driver_probe(&cmos_platform_driver,
                        cmos_platform_probe);
}
module_init(cmos_init);

static void __exit cmos_exit(void)
{
        platform_driver_unregister(&cmos_platform_driver);
}
module_exit(cmos_exit);


#endif  /* !PNP */

MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
MODULE_LICENSE("GPL");