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path: root/drivers/rtc/rtc-cmos.c
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-rw-r--r--drivers/rtc/rtc-cmos.c725
1 files changed, 725 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
new file mode 100644
index 00000000000..85bf795abdc
--- /dev/null
+++ b/drivers/rtc/rtc-cmos.c
@@ -0,0 +1,725 @@
+/*
+ * 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;
+
+ 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";
+
+/*----------------------------------------------------------------*/
+
+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);
+ if (rtc_intr)
+ rtc_update_irq(&cmos->rtc->class_dev, 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);
+ if (rtc_intr)
+ rtc_update_irq(&cmos->rtc->class_dev, 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);
+ if (rtc_intr)
+ rtc_update_irq(&cmos->rtc->class_dev, 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);
+ spin_unlock(&rtc_lock);
+
+ if (irqstat) {
+ /* NOTE: irqstat may have e.g. RTC_PF set
+ * even when RTC_PIE is clear...
+ */
+ rtc_update_irq(p, 1, irqstat);
+ return IRQ_HANDLED;
+ } else
+ return IRQ_NONE;
+}
+
+#ifdef CONFIG_PNPACPI
+#define is_pnpacpi() 1
+#define INITSECTION
+
+#else
+#define is_pnpacpi() 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 the info comes from the FADT. On others,
+ * board specific setup provides it as appropriate.
+ */
+ if (info) {
+ cmos_rtc.day_alrm = info->rtc_day_alarm;
+ cmos_rtc.mon_alrm = info->rtc_mon_alarm;
+ cmos_rtc.century = info->rtc_century;
+ }
+
+ 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_pnpacpi()) {
+ 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->class_dev.class_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->class_dev.class_id,
+ &cmos_rtc.rtc->class_dev);
+ 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->class_dev.class_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_pnpacpi())
+ release_resource(cmos->iomem);
+ rename_region(cmos->iomem, NULL);
+
+ if (is_valid_irq(cmos->irq))
+ free_irq(cmos->irq, &cmos_rtc.rtc->class_dev);
+
+ 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, irqstat;
+
+ /* 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)) {
+ 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);
+ } else
+ irqstat = 0;
+ spin_unlock_irq(&rtc_lock);
+
+ if (irqstat)
+ rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);
+
+ /* ACPI HOOK: enable ACPI_EVENT_RTC when (tmp & RTC_AIE)
+ * ... it'd be best if we could do that under rtc_lock.
+ */
+
+ pr_debug("%s: suspend%s, ctrl %02x\n",
+ cmos_rtc.rtc->class_dev.class_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;
+
+ /* REVISIT: a mechanism to resync the system clock (jiffies)
+ * on resume should be portable between platforms ...
+ */
+
+ /* re-enable any irqs previously active */
+ if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
+
+ /* ACPI HOOK: disable ACPI_EVENT_RTC when (tmp & RTC_AIE) */
+
+ spin_lock_irq(&rtc_lock);
+ CMOS_WRITE(tmp, RTC_CONTROL);
+ tmp = CMOS_READ(RTC_INTR_FLAGS);
+ spin_unlock_irq(&rtc_lock);
+ if (tmp)
+ rtc_update_irq(&cmos->rtc->class_dev, 1, tmp);
+ }
+
+ pr_debug("%s: resume, ctrl %02x\n",
+ cmos_rtc.rtc->class_dev.class_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 may alternatively be created as a PNP device.
+ */
+
+#ifdef CONFIG_PNPACPI
+
+#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 PNPACPI */
+
+/*----------------------------------------------------------------*/
+
+/* Platform setup should have set up an RTC device, when PNPACPI is
+ * unavailable ... this is the normal case, common even on 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 /* !PNPACPI */
+
+MODULE_AUTHOR("David Brownell");
+MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
+MODULE_LICENSE("GPL");