RTC: M48T35: new RTC driver
This driver replaces the broken ip27-rtc driver in drivers/char and gives back RTC support for SGI IP27 machines. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Thomas Bogendoerfer
Ralf Baechle
parent
3ec066cdb7
commit
d1dbd82e2f
@ -410,6 +410,15 @@ config RTC_DRV_M48T86
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This driver can also be built as a module. If so, the module
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will be called rtc-m48t86.
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config RTC_DRV_M48T35
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tristate "ST M48T35"
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help
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If you say Y here you will get support for the
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ST M48T35 RTC chip.
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This driver can also be built as a module, if so, the module
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will be called "rtc-m48t35".
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config RTC_DRV_M48T59
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tristate "ST M48T59/M48T08/M48T02"
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help
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@ -37,6 +37,7 @@ obj-$(CONFIG_RTC_DRV_FM3130) += rtc-fm3130.o
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obj-$(CONFIG_RTC_DRV_ISL1208) += rtc-isl1208.o
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obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o
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obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o
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obj-$(CONFIG_RTC_DRV_M48T35) += rtc-m48t35.o
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obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o
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obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
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obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o
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234
drivers/rtc/rtc-m48t35.c
Normal file
234
drivers/rtc/rtc-m48t35.c
Normal file
@ -0,0 +1,234 @@
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/*
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* Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
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*
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* Copyright (C) 2000 Silicon Graphics, Inc.
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* Written by Ulf Carlsson (ulfc@engr.sgi.com)
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*
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* Copyright (C) 2008 Thomas Bogendoerfer
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*
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* Based on code written by Paul Gortmaker.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/rtc.h>
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#include <linux/platform_device.h>
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#include <linux/bcd.h>
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#define DRV_VERSION "1.0"
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struct m48t35_rtc {
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u8 pad[0x7ff8]; /* starts at 0x7ff8 */
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u8 control;
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u8 sec;
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u8 min;
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u8 hour;
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u8 day;
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u8 date;
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u8 month;
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u8 year;
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};
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#define M48T35_RTC_SET 0x80
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#define M48T35_RTC_READ 0x40
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struct m48t35_priv {
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struct rtc_device *rtc;
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struct m48t35_rtc __iomem *reg;
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size_t size;
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unsigned long baseaddr;
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spinlock_t lock;
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};
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static int m48t35_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct m48t35_priv *priv = dev_get_drvdata(dev);
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u8 control;
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/*
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* Only the values that we read from the RTC are set. We leave
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* tm_wday, tm_yday and tm_isdst untouched. Even though the
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* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
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* by the RTC when initially set to a non-zero value.
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*/
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spin_lock_irq(&priv->lock);
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control = readb(&priv->reg->control);
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writeb(control | M48T35_RTC_READ, &priv->reg->control);
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tm->tm_sec = readb(&priv->reg->sec);
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tm->tm_min = readb(&priv->reg->min);
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tm->tm_hour = readb(&priv->reg->hour);
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tm->tm_mday = readb(&priv->reg->date);
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tm->tm_mon = readb(&priv->reg->month);
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tm->tm_year = readb(&priv->reg->year);
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writeb(control, &priv->reg->control);
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spin_unlock_irq(&priv->lock);
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tm->tm_sec = bcd2bin(tm->tm_sec);
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tm->tm_min = bcd2bin(tm->tm_min);
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tm->tm_hour = bcd2bin(tm->tm_hour);
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tm->tm_mday = bcd2bin(tm->tm_mday);
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tm->tm_mon = bcd2bin(tm->tm_mon);
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tm->tm_year = bcd2bin(tm->tm_year);
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/*
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* Account for differences between how the RTC uses the values
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* and how they are defined in a struct rtc_time;
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*/
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tm->tm_year += 70;
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if (tm->tm_year <= 69)
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tm->tm_year += 100;
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tm->tm_mon--;
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return rtc_valid_tm(tm);
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}
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static int m48t35_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct m48t35_priv *priv = dev_get_drvdata(dev);
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unsigned char mon, day, hrs, min, sec;
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unsigned int yrs;
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u8 control;
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yrs = tm->tm_year + 1900;
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mon = tm->tm_mon + 1; /* tm_mon starts at zero */
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day = tm->tm_mday;
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hrs = tm->tm_hour;
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min = tm->tm_min;
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sec = tm->tm_sec;
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if (yrs < 1970)
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return -EINVAL;
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yrs -= 1970;
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if (yrs > 255) /* They are unsigned */
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return -EINVAL;
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if (yrs > 169)
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return -EINVAL;
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if (yrs >= 100)
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yrs -= 100;
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sec = bin2bcd(sec);
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min = bin2bcd(min);
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hrs = bin2bcd(hrs);
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day = bin2bcd(day);
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mon = bin2bcd(mon);
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yrs = bin2bcd(yrs);
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spin_lock_irq(&priv->lock);
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control = readb(&priv->reg->control);
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writeb(control | M48T35_RTC_SET, &priv->reg->control);
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writeb(yrs, &priv->reg->year);
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writeb(mon, &priv->reg->month);
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writeb(day, &priv->reg->date);
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writeb(hrs, &priv->reg->hour);
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writeb(min, &priv->reg->min);
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writeb(sec, &priv->reg->sec);
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writeb(control, &priv->reg->control);
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spin_unlock_irq(&priv->lock);
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return 0;
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}
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static const struct rtc_class_ops m48t35_ops = {
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.read_time = m48t35_read_time,
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.set_time = m48t35_set_time,
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};
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static int __devinit m48t35_probe(struct platform_device *pdev)
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{
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struct rtc_device *rtc;
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struct resource *res;
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struct m48t35_priv *priv;
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int ret = 0;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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priv = kzalloc(sizeof(struct m48t35_priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->size = res->end - res->start + 1;
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/*
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* kludge: remove the #ifndef after ioc3 resource
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* conflicts are resolved
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*/
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#ifndef CONFIG_SGI_IP27
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if (!request_mem_region(res->start, priv->size, pdev->name)) {
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ret = -EBUSY;
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goto out;
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}
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#endif
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priv->baseaddr = res->start;
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priv->reg = ioremap(priv->baseaddr, priv->size);
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if (!priv->reg) {
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ret = -ENOMEM;
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goto out;
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}
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spin_lock_init(&priv->lock);
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rtc = rtc_device_register("m48t35", &pdev->dev,
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&m48t35_ops, THIS_MODULE);
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if (IS_ERR(rtc)) {
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ret = PTR_ERR(rtc);
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goto out;
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}
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priv->rtc = rtc;
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platform_set_drvdata(pdev, priv);
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return 0;
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out:
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if (priv->rtc)
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rtc_device_unregister(priv->rtc);
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if (priv->reg)
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iounmap(priv->reg);
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if (priv->baseaddr)
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release_mem_region(priv->baseaddr, priv->size);
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kfree(priv);
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return ret;
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}
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static int __devexit m48t35_remove(struct platform_device *pdev)
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{
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struct m48t35_priv *priv = platform_get_drvdata(pdev);
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rtc_device_unregister(priv->rtc);
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iounmap(priv->reg);
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#ifndef CONFIG_SGI_IP27
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release_mem_region(priv->baseaddr, priv->size);
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#endif
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kfree(priv);
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return 0;
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}
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static struct platform_driver m48t35_platform_driver = {
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.driver = {
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.name = "rtc-m48t35",
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.owner = THIS_MODULE,
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},
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.probe = m48t35_probe,
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.remove = __devexit_p(m48t35_remove),
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};
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static int __init m48t35_init(void)
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{
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return platform_driver_register(&m48t35_platform_driver);
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}
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static void __exit m48t35_exit(void)
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{
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platform_driver_unregister(&m48t35_platform_driver);
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}
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MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
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MODULE_DESCRIPTION("M48T35 RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_VERSION);
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MODULE_ALIAS("platform:rtc-m48t35");
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module_init(m48t35_init);
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module_exit(m48t35_exit);
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