[PATCH] RTC: add rtc-ds1742 driver
Add an RTC driver for the Dallas DS1742 RTC chip. [akpm@osdl.org: cleanups, compile fix] Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Atsushi Nemoto
Linus Torvalds
parent
9bf5b4f5f5
commit
5ec3e4b7ae
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@ -131,6 +131,16 @@ config RTC_DRV_DS1672
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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-ds1672.
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config RTC_DRV_DS1742
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tristate "Dallas DS1742"
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depends on RTC_CLASS
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help
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If you say yes here you get support for the
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Dallas DS1742 timekeeping 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-ds1742.
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config RTC_DRV_PCF8563
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tristate "Philips PCF8563/Epson RTC8564"
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depends on RTC_CLASS && I2C
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@ -15,6 +15,7 @@ obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
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obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o
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obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o
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obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
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obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o
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obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
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obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
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obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
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259
drivers/rtc/rtc-ds1742.c
Normal file
259
drivers/rtc/rtc-ds1742.c
Normal file
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@ -0,0 +1,259 @@
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/*
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* An rtc driver for the Dallas DS1742
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*
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* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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*
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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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*/
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#include <linux/bcd.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/jiffies.h>
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#include <linux/rtc.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#define DRV_VERSION "0.1"
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#define RTC_REG_SIZE 0x800
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#define RTC_OFFSET 0x7f8
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#define RTC_CONTROL (RTC_OFFSET + 0)
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#define RTC_CENTURY (RTC_OFFSET + 0)
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#define RTC_SECONDS (RTC_OFFSET + 1)
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#define RTC_MINUTES (RTC_OFFSET + 2)
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#define RTC_HOURS (RTC_OFFSET + 3)
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#define RTC_DAY (RTC_OFFSET + 4)
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#define RTC_DATE (RTC_OFFSET + 5)
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#define RTC_MONTH (RTC_OFFSET + 6)
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#define RTC_YEAR (RTC_OFFSET + 7)
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#define RTC_CENTURY_MASK 0x3f
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#define RTC_SECONDS_MASK 0x7f
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#define RTC_DAY_MASK 0x07
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/* Bits in the Control/Century register */
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#define RTC_WRITE 0x80
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#define RTC_READ 0x40
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/* Bits in the Seconds register */
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#define RTC_STOP 0x80
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/* Bits in the Day register */
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#define RTC_BATT_FLAG 0x80
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struct rtc_plat_data {
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struct rtc_device *rtc;
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void __iomem *ioaddr;
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unsigned long baseaddr;
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unsigned long last_jiffies;
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};
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static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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void __iomem *ioaddr = pdata->ioaddr;
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u8 century;
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century = BIN2BCD((tm->tm_year + 1900) / 100);
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writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
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writeb(BIN2BCD(tm->tm_year % 100), ioaddr + RTC_YEAR);
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writeb(BIN2BCD(tm->tm_mon + 1), ioaddr + RTC_MONTH);
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writeb(BIN2BCD(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
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writeb(BIN2BCD(tm->tm_mday), ioaddr + RTC_DATE);
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writeb(BIN2BCD(tm->tm_hour), ioaddr + RTC_HOURS);
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writeb(BIN2BCD(tm->tm_min), ioaddr + RTC_MINUTES);
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writeb(BIN2BCD(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
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/* RTC_CENTURY and RTC_CONTROL share same register */
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writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
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writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
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return 0;
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}
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static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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void __iomem *ioaddr = pdata->ioaddr;
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unsigned int year, month, day, hour, minute, second, week;
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unsigned int century;
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/* give enough time to update RTC in case of continuous read */
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if (pdata->last_jiffies == jiffies)
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msleep(1);
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pdata->last_jiffies = jiffies;
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writeb(RTC_READ, ioaddr + RTC_CONTROL);
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second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
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minute = readb(ioaddr + RTC_MINUTES);
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hour = readb(ioaddr + RTC_HOURS);
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day = readb(ioaddr + RTC_DATE);
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week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
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month = readb(ioaddr + RTC_MONTH);
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year = readb(ioaddr + RTC_YEAR);
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century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
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writeb(0, ioaddr + RTC_CONTROL);
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tm->tm_sec = BCD2BIN(second);
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tm->tm_min = BCD2BIN(minute);
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tm->tm_hour = BCD2BIN(hour);
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tm->tm_mday = BCD2BIN(day);
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tm->tm_wday = BCD2BIN(week);
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tm->tm_mon = BCD2BIN(month) - 1;
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/* year is 1900 + tm->tm_year */
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tm->tm_year = BCD2BIN(year) + BCD2BIN(century) * 100 - 1900;
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if (rtc_valid_tm(tm) < 0) {
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dev_err(dev, "retrieved date/time is not valid.\n");
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rtc_time_to_tm(0, tm);
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}
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return 0;
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}
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static struct rtc_class_ops ds1742_rtc_ops = {
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.read_time = ds1742_rtc_read_time,
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.set_time = ds1742_rtc_set_time,
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};
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static ssize_t ds1742_nvram_read(struct kobject *kobj, char *buf,
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loff_t pos, size_t size)
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{
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struct platform_device *pdev =
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to_platform_device(container_of(kobj, struct device, kobj));
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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void __iomem *ioaddr = pdata->ioaddr;
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ssize_t count;
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for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
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*buf++ = readb(ioaddr + pos++);
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return count;
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}
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static ssize_t ds1742_nvram_write(struct kobject *kobj, char *buf,
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loff_t pos, size_t size)
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{
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struct platform_device *pdev =
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to_platform_device(container_of(kobj, struct device, kobj));
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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void __iomem *ioaddr = pdata->ioaddr;
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ssize_t count;
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for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
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writeb(*buf++, ioaddr + pos++);
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return count;
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}
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static struct bin_attribute ds1742_nvram_attr = {
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.attr = {
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.name = "nvram",
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.mode = S_IRUGO | S_IWUGO,
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.owner = THIS_MODULE,
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},
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.size = RTC_OFFSET,
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.read = ds1742_nvram_read,
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.write = ds1742_nvram_write,
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};
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static int __init ds1742_rtc_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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unsigned int cen, sec;
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struct rtc_plat_data *pdata = NULL;
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void __iomem *ioaddr = NULL;
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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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pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
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ret = -EBUSY;
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goto out;
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}
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pdata->baseaddr = res->start;
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ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
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if (!ioaddr) {
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ret = -ENOMEM;
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goto out;
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}
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pdata->ioaddr = ioaddr;
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/* turn RTC on if it was not on */
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sec = readb(ioaddr + RTC_SECONDS);
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if (sec & RTC_STOP) {
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sec &= RTC_SECONDS_MASK;
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cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
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writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
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writeb(sec, ioaddr + RTC_SECONDS);
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writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
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}
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if (readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)
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dev_warn(&pdev->dev, "voltage-low detected.\n");
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rtc = rtc_device_register(pdev->name, &pdev->dev,
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&ds1742_rtc_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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pdata->rtc = rtc;
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pdata->last_jiffies = jiffies;
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platform_set_drvdata(pdev, pdata);
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sysfs_create_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr);
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return 0;
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out:
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if (ioaddr)
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iounmap(ioaddr);
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if (pdata->baseaddr)
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release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
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kfree(pdata);
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return ret;
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}
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static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
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{
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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sysfs_remove_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr);
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rtc_device_unregister(pdata->rtc);
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iounmap(pdata->ioaddr);
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release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
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kfree(pdata);
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return 0;
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}
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static struct platform_driver ds1742_rtc_driver = {
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.probe = ds1742_rtc_probe,
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.remove = __devexit_p(ds1742_rtc_remove),
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.driver = {
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.name = "ds1742",
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.owner = THIS_MODULE,
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},
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};
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static __init int ds1742_init(void)
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{
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return platform_driver_register(&ds1742_rtc_driver);
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}
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static __exit void ds1742_exit(void)
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{
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return platform_driver_unregister(&ds1742_rtc_driver);
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}
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module_init(ds1742_init);
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module_exit(ds1742_exit);
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MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
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MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_VERSION);
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