363 lines
10 KiB
C
363 lines
10 KiB
C
/*
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* An rtc driver for the Dallas DS1553
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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/gfp.h>
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#include <linux/delay.h>
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#include <linux/jiffies.h>
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#include <linux/interrupt.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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#include <linux/module.h>
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#define DRV_VERSION "0.3"
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#define RTC_REG_SIZE 0x2000
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#define RTC_OFFSET 0x1ff0
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#define RTC_FLAGS (RTC_OFFSET + 0)
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#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
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#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
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#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
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#define RTC_DATE_ALARM (RTC_OFFSET + 5)
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#define RTC_INTERRUPTS (RTC_OFFSET + 6)
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#define RTC_WATCHDOG (RTC_OFFSET + 7)
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#define RTC_CONTROL (RTC_OFFSET + 8)
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#define RTC_CENTURY (RTC_OFFSET + 8)
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#define RTC_SECONDS (RTC_OFFSET + 9)
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#define RTC_MINUTES (RTC_OFFSET + 10)
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#define RTC_HOURS (RTC_OFFSET + 11)
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#define RTC_DAY (RTC_OFFSET + 12)
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#define RTC_DATE (RTC_OFFSET + 13)
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#define RTC_MONTH (RTC_OFFSET + 14)
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#define RTC_YEAR (RTC_OFFSET + 15)
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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 Flags register */
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#define RTC_FLAGS_AF 0x40
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#define RTC_FLAGS_BLF 0x10
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/* Bits in the Interrupts register */
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#define RTC_INTS_AE 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 last_jiffies;
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int irq;
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unsigned int irqen;
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int alrm_sec;
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int alrm_min;
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int alrm_hour;
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int alrm_mday;
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spinlock_t lock;
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};
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static int ds1553_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, pdata->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 ds1553_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 void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
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{
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void __iomem *ioaddr = pdata->ioaddr;
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unsigned long flags;
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spin_lock_irqsave(&pdata->lock, flags);
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writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
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0x80 : bin2bcd(pdata->alrm_mday),
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ioaddr + RTC_DATE_ALARM);
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writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
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0x80 : bin2bcd(pdata->alrm_hour),
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ioaddr + RTC_HOURS_ALARM);
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writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
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0x80 : bin2bcd(pdata->alrm_min),
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ioaddr + RTC_MINUTES_ALARM);
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writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
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0x80 : bin2bcd(pdata->alrm_sec),
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ioaddr + RTC_SECONDS_ALARM);
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writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
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readb(ioaddr + RTC_FLAGS); /* clear interrupts */
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spin_unlock_irqrestore(&pdata->lock, flags);
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}
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static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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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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if (pdata->irq <= 0)
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return -EINVAL;
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pdata->alrm_mday = alrm->time.tm_mday;
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pdata->alrm_hour = alrm->time.tm_hour;
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pdata->alrm_min = alrm->time.tm_min;
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pdata->alrm_sec = alrm->time.tm_sec;
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if (alrm->enabled)
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pdata->irqen |= RTC_AF;
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ds1553_rtc_update_alarm(pdata);
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return 0;
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}
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static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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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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if (pdata->irq <= 0)
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return -EINVAL;
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alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
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alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
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alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
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alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
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alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
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return 0;
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}
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static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
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{
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struct platform_device *pdev = dev_id;
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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 long events = 0;
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spin_lock(&pdata->lock);
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/* read and clear interrupt */
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if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
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events = RTC_IRQF;
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if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
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events |= RTC_UF;
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else
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events |= RTC_AF;
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rtc_update_irq(pdata->rtc, 1, events);
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}
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spin_unlock(&pdata->lock);
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return events ? IRQ_HANDLED : IRQ_NONE;
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}
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static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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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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if (pdata->irq <= 0)
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return -EINVAL;
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if (enabled)
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pdata->irqen |= RTC_AF;
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else
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pdata->irqen &= ~RTC_AF;
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ds1553_rtc_update_alarm(pdata);
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return 0;
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}
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static const struct rtc_class_ops ds1553_rtc_ops = {
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.read_time = ds1553_rtc_read_time,
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.set_time = ds1553_rtc_set_time,
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.read_alarm = ds1553_rtc_read_alarm,
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.set_alarm = ds1553_rtc_set_alarm,
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.alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
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};
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static ssize_t ds1553_nvram_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t pos, size_t size)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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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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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 ds1553_nvram_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t pos, size_t size)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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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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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 ds1553_nvram_attr = {
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.attr = {
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.name = "nvram",
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.mode = S_IRUGO | S_IWUSR,
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},
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.size = RTC_OFFSET,
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.read = ds1553_nvram_read,
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.write = ds1553_nvram_write,
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};
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static int ds1553_rtc_probe(struct platform_device *pdev)
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{
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struct resource *res;
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unsigned int cen, sec;
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struct rtc_plat_data *pdata;
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void __iomem *ioaddr;
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int ret = 0;
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pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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ioaddr = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(ioaddr))
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return PTR_ERR(ioaddr);
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pdata->ioaddr = ioaddr;
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pdata->irq = platform_get_irq(pdev, 0);
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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_FLAGS) & RTC_FLAGS_BLF)
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dev_warn(&pdev->dev, "voltage-low detected.\n");
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spin_lock_init(&pdata->lock);
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pdata->last_jiffies = jiffies;
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platform_set_drvdata(pdev, pdata);
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pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
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&ds1553_rtc_ops, THIS_MODULE);
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if (IS_ERR(pdata->rtc))
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return PTR_ERR(pdata->rtc);
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if (pdata->irq > 0) {
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writeb(0, ioaddr + RTC_INTERRUPTS);
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if (devm_request_irq(&pdev->dev, pdata->irq,
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ds1553_rtc_interrupt,
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0, pdev->name, pdev) < 0) {
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dev_warn(&pdev->dev, "interrupt not available.\n");
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pdata->irq = 0;
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}
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}
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ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
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if (ret)
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dev_err(&pdev->dev, "unable to create sysfs file: %s\n",
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ds1553_nvram_attr.attr.name);
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return 0;
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}
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static int ds1553_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, &ds1553_nvram_attr);
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if (pdata->irq > 0)
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writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
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return 0;
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}
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/* work with hotplug and coldplug */
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MODULE_ALIAS("platform:rtc-ds1553");
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static struct platform_driver ds1553_rtc_driver = {
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.probe = ds1553_rtc_probe,
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.remove = ds1553_rtc_remove,
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.driver = {
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.name = "rtc-ds1553",
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},
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};
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module_platform_driver(ds1553_rtc_driver);
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MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
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MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_VERSION);
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