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* Real Time Clock driver for Freescale MC13XXX PMIC
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* (C) 2009 Sascha Hauer, Pengutronix
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* (C) 2009 Uwe Kleine-Koenig, Pengutronix
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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#include <linux/mfd/mc13xxx.h>
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#include <linux/platform_device.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/rtc.h>
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#define DRIVER_NAME "mc13xxx-rtc"
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#define MC13XXX_RTCTOD 20
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#define MC13XXX_RTCTODA 21
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#define MC13XXX_RTCDAY 22
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#define MC13XXX_RTCDAYA 23
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struct rtc_device *rtc;
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struct mc13xxx *mc13xxx;
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static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev,
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unsigned int enabled, int irq)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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int (*func)(struct mc13xxx *mc13xxx, int irq);
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func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask;
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return func(priv->mc13xxx, irq);
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static int mc13xxx_rtc_irq_enable(struct device *dev,
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unsigned int enabled, int irq)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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mc13xxx_lock(priv->mc13xxx);
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ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, irq);
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mc13xxx_unlock(priv->mc13xxx);
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static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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unsigned int seconds, days1, days2;
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mc13xxx_lock(priv->mc13xxx);
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
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mc13xxx_unlock(priv->mc13xxx);
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if (days2 == days1 + 1) {
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if (seconds >= 86400 / 2)
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s1970 = days1 * 86400 + seconds;
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rtc_time_to_tm(s1970, tm);
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return rtc_valid_tm(tm);
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static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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unsigned int seconds, days;
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unsigned int alarmseconds;
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seconds = secs % 86400;
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mc13xxx_lock(priv->mc13xxx);
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* temporarily invalidate alarm to prevent triggering it when the day is
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* already updated while the time isn't yet.
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
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if (alarmseconds < 86400) {
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ret = mc13xxx_reg_write(priv->mc13xxx,
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MC13XXX_RTCTODA, 0x1ffff);
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* write seconds=0 to prevent a day switch between writing days
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
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if (alarmseconds < 86400) {
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ret = mc13xxx_reg_write(priv->mc13xxx,
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MC13XXX_RTCTODA, alarmseconds);
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ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
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ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
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mc13xxx_unlock(priv->mc13xxx);
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static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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unsigned seconds, days;
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int enabled, pending;
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mc13xxx_lock(priv->mc13xxx);
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
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if (seconds >= 86400) {
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
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ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
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mc13xxx_unlock(priv->mc13xxx);
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alarm->enabled = enabled;
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alarm->pending = pending;
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s1970 = days * 86400 + seconds;
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rtc_time_to_tm(s1970, &alarm->time);
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dev_dbg(dev, "%s: %lu\n", __func__, s1970);
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static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
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unsigned seconds, days;
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mc13xxx_lock(priv->mc13xxx);
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/* disable alarm to prevent false triggering */
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
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ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
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ret = rtc_tm_to_time(&alarm->time, &s1970);
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dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
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ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
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seconds = s1970 % 86400;
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days = s1970 / 86400;
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
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mc13xxx_unlock(priv->mc13xxx);
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static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
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struct mc13xxx_rtc *priv = dev;
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struct mc13xxx *mc13xxx = priv->mc13xxx;
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dev_dbg(&priv->rtc->dev, "Alarm\n");
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rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
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mc13xxx_irq_ack(mc13xxx, irq);
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static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
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struct mc13xxx_rtc *priv = dev;
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struct mc13xxx *mc13xxx = priv->mc13xxx;
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dev_dbg(&priv->rtc->dev, "1HZ\n");
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rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
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mc13xxx_irq_ack(mc13xxx, irq);
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static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enabled)
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return mc13xxx_rtc_irq_enable(dev, enabled, MC13XXX_IRQ_TODA);
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static const struct rtc_class_ops mc13xxx_rtc_ops = {
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.read_time = mc13xxx_rtc_read_time,
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.set_mmss = mc13xxx_rtc_set_mmss,
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.read_alarm = mc13xxx_rtc_read_alarm,
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.set_alarm = mc13xxx_rtc_set_alarm,
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.alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
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static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
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struct mc13xxx_rtc *priv = dev;
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struct mc13xxx *mc13xxx = priv->mc13xxx;
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dev_dbg(&priv->rtc->dev, "RTCRST\n");
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mc13xxx_irq_mask(mc13xxx, irq);
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static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
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struct mc13xxx_rtc *priv;
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struct mc13xxx *mc13xxx;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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mc13xxx = dev_get_drvdata(pdev->dev.parent);
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priv->mc13xxx = mc13xxx;
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platform_set_drvdata(pdev, priv);
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mc13xxx_lock(mc13xxx);
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ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
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mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
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goto err_reset_irq_request;
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ret = mc13xxx_irq_status(mc13xxx, MC13XXX_IRQ_RTCRST,
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NULL, &rtcrst_pending);
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goto err_reset_irq_status;
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priv->valid = !rtcrst_pending;
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ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_1HZ,
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mc13xxx_rtc_update_handler, DRIVER_NAME, priv);
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goto err_update_irq_request;
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ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
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mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
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goto err_alarm_irq_request;
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mc13xxx_unlock(mc13xxx);
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priv->rtc = rtc_device_register(pdev->name,
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&pdev->dev, &mc13xxx_rtc_ops, THIS_MODULE);
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if (IS_ERR(priv->rtc)) {
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ret = PTR_ERR(priv->rtc);
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mc13xxx_lock(mc13xxx);
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mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
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err_alarm_irq_request:
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mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_1HZ, priv);
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err_update_irq_request:
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err_reset_irq_status:
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mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
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err_reset_irq_request:
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mc13xxx_unlock(mc13xxx);
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platform_set_drvdata(pdev, NULL);
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static int __exit mc13xxx_rtc_remove(struct platform_device *pdev)
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struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
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mc13xxx_lock(priv->mc13xxx);
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rtc_device_unregister(priv->rtc);
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mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
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mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_1HZ, priv);
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mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
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mc13xxx_unlock(priv->mc13xxx);
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platform_set_drvdata(pdev, NULL);
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const struct platform_device_id mc13xxx_rtc_idtable[] = {
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.name = "mc13783-rtc",
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.name = "mc13892-rtc",
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static struct platform_driver mc13xxx_rtc_driver = {
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.id_table = mc13xxx_rtc_idtable,
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.remove = __exit_p(mc13xxx_rtc_remove),
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.owner = THIS_MODULE,
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static int __init mc13xxx_rtc_init(void)
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return platform_driver_probe(&mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
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module_init(mc13xxx_rtc_init);
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static void __exit mc13xxx_rtc_exit(void)
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platform_driver_unregister(&mc13xxx_rtc_driver);
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module_exit(mc13xxx_rtc_exit);
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MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
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MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:" DRIVER_NAME);