407 lines
10 KiB
C
407 lines
10 KiB
C
/*
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* Real Time Clock interface for Linux on Atmel AT91RM9200
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*
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* Copyright (C) 2002 Rick Bronson
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*
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* Converted to RTC class model by Andrew Victor
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*
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* Ported to Linux 2.6 by Steven Scholz
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* Based on s3c2410-rtc.c Simtec Electronics
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*
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* Based on sa1100-rtc.c by Nils Faerber
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* Based on rtc.c by Paul Gortmaker
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/time.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/interrupt.h>
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#include <linux/ioctl.h>
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#include <linux/completion.h>
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#include <asm/uaccess.h>
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#include <mach/at91_rtc.h>
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#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
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static DECLARE_COMPLETION(at91_rtc_updated);
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static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
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/*
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* Decode time/date into rtc_time structure
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*/
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static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
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struct rtc_time *tm)
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{
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unsigned int time, date;
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/* must read twice in case it changes */
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do {
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time = at91_sys_read(timereg);
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date = at91_sys_read(calreg);
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} while ((time != at91_sys_read(timereg)) ||
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(date != at91_sys_read(calreg)));
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tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
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tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
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tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
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/*
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* The Calendar Alarm register does not have a field for
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* the year - so these will return an invalid value. When an
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* alarm is set, at91_alarm_year wille store the current year.
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*/
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tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
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tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
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tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
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tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
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tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
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}
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/*
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* Read current time and date in RTC
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*/
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static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
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{
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at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
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tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
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tm->tm_year = tm->tm_year - 1900;
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pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
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1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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return 0;
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}
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/*
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* Set current time and date in RTC
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*/
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static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
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{
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unsigned long cr;
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pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
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1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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/* Stop Time/Calendar from counting */
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cr = at91_sys_read(AT91_RTC_CR);
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at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
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at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
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wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
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at91_sys_write(AT91_RTC_TIMR,
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bin2bcd(tm->tm_sec) << 0
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| bin2bcd(tm->tm_min) << 8
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| bin2bcd(tm->tm_hour) << 16);
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at91_sys_write(AT91_RTC_CALR,
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bin2bcd((tm->tm_year + 1900) / 100) /* century */
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| bin2bcd(tm->tm_year % 100) << 8 /* year */
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| bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
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| bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
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| bin2bcd(tm->tm_mday) << 24);
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/* Restart Time/Calendar */
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cr = at91_sys_read(AT91_RTC_CR);
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at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
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return 0;
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}
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/*
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* Read alarm time and date in RTC
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*/
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static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct rtc_time *tm = &alrm->time;
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at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
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tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
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tm->tm_year = at91_alarm_year - 1900;
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alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
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? 1 : 0;
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pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
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1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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return 0;
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}
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/*
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* Set alarm time and date in RTC
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*/
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static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct rtc_time tm;
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at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
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at91_alarm_year = tm.tm_year;
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tm.tm_hour = alrm->time.tm_hour;
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tm.tm_min = alrm->time.tm_min;
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tm.tm_sec = alrm->time.tm_sec;
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
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at91_sys_write(AT91_RTC_TIMALR,
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bin2bcd(tm.tm_sec) << 0
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| bin2bcd(tm.tm_min) << 8
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| bin2bcd(tm.tm_hour) << 16
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| AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
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at91_sys_write(AT91_RTC_CALALR,
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bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
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| bin2bcd(tm.tm_mday) << 24
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| AT91_RTC_DATEEN | AT91_RTC_MTHEN);
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if (alrm->enabled) {
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at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
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at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
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}
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pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
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at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
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tm.tm_min, tm.tm_sec);
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return 0;
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}
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/*
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* Handle commands from user-space
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*/
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static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
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unsigned long arg)
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{
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int ret = 0;
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pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
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/* important: scrub old status before enabling IRQs */
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switch (cmd) {
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case RTC_AIE_OFF: /* alarm off */
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
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break;
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case RTC_AIE_ON: /* alarm on */
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at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
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at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
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break;
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case RTC_UIE_OFF: /* update off */
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
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break;
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case RTC_UIE_ON: /* update on */
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at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
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at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
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break;
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default:
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ret = -ENOIOCTLCMD;
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break;
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}
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return ret;
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}
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/*
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* Provide additional RTC information in /proc/driver/rtc
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*/
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static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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unsigned long imr = at91_sys_read(AT91_RTC_IMR);
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seq_printf(seq, "update_IRQ\t: %s\n",
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(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
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seq_printf(seq, "periodic_IRQ\t: %s\n",
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(imr & AT91_RTC_SECEV) ? "yes" : "no");
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return 0;
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}
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/*
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* IRQ handler for the RTC
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*/
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static irqreturn_t at91_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_device *rtc = platform_get_drvdata(pdev);
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unsigned int rtsr;
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unsigned long events = 0;
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rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
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if (rtsr) { /* this interrupt is shared! Is it ours? */
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if (rtsr & AT91_RTC_ALARM)
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events |= (RTC_AF | RTC_IRQF);
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if (rtsr & AT91_RTC_SECEV)
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events |= (RTC_UF | RTC_IRQF);
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if (rtsr & AT91_RTC_ACKUPD)
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complete(&at91_rtc_updated);
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at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
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rtc_update_irq(rtc, 1, events);
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pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
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events >> 8, events & 0x000000FF);
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return IRQ_HANDLED;
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}
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return IRQ_NONE; /* not handled */
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}
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static const struct rtc_class_ops at91_rtc_ops = {
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.ioctl = at91_rtc_ioctl,
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.read_time = at91_rtc_readtime,
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.set_time = at91_rtc_settime,
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.read_alarm = at91_rtc_readalarm,
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.set_alarm = at91_rtc_setalarm,
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.proc = at91_rtc_proc,
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};
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/*
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* Initialize and install RTC driver
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*/
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static int __init at91_rtc_probe(struct platform_device *pdev)
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{
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struct rtc_device *rtc;
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int ret;
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at91_sys_write(AT91_RTC_CR, 0);
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at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
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/* Disable all interrupts */
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
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AT91_RTC_SECEV | AT91_RTC_TIMEV |
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AT91_RTC_CALEV);
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ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
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IRQF_SHARED,
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"at91_rtc", pdev);
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if (ret) {
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printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
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AT91_ID_SYS);
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return ret;
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}
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/* cpu init code should really have flagged this device as
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* being wake-capable; if it didn't, do that here.
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*/
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if (!device_can_wakeup(&pdev->dev))
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device_init_wakeup(&pdev->dev, 1);
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rtc = rtc_device_register(pdev->name, &pdev->dev,
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&at91_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc)) {
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free_irq(AT91_ID_SYS, pdev);
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return PTR_ERR(rtc);
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}
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platform_set_drvdata(pdev, rtc);
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printk(KERN_INFO "AT91 Real Time Clock driver.\n");
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return 0;
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}
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/*
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* Disable and remove the RTC driver
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*/
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static int __exit at91_rtc_remove(struct platform_device *pdev)
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{
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struct rtc_device *rtc = platform_get_drvdata(pdev);
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/* Disable all interrupts */
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at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
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AT91_RTC_SECEV | AT91_RTC_TIMEV |
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AT91_RTC_CALEV);
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free_irq(AT91_ID_SYS, pdev);
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rtc_device_unregister(rtc);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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#ifdef CONFIG_PM
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/* AT91RM9200 RTC Power management control */
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static u32 at91_rtc_imr;
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static int at91_rtc_suspend(struct device *dev)
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{
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/* this IRQ is shared with DBGU and other hardware which isn't
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* necessarily doing PM like we are...
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*/
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at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
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& (AT91_RTC_ALARM|AT91_RTC_SECEV);
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if (at91_rtc_imr) {
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if (device_may_wakeup(dev))
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enable_irq_wake(AT91_ID_SYS);
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else
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at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
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}
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return 0;
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}
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static int at91_rtc_resume(struct device *dev)
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{
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if (at91_rtc_imr) {
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if (device_may_wakeup(dev))
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disable_irq_wake(AT91_ID_SYS);
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else
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at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
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}
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return 0;
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}
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static const struct dev_pm_ops at91_rtc_pm = {
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.suspend = at91_rtc_suspend,
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.resume = at91_rtc_resume,
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};
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#define at91_rtc_pm_ptr &at91_rtc_pm
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#else
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#define at91_rtc_pm_ptr NULL
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#endif
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static struct platform_driver at91_rtc_driver = {
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.remove = __exit_p(at91_rtc_remove),
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.driver = {
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.name = "at91_rtc",
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.owner = THIS_MODULE,
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.pm = at91_rtc_pm_ptr,
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},
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};
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static int __init at91_rtc_init(void)
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{
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return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
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}
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static void __exit at91_rtc_exit(void)
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{
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platform_driver_unregister(&at91_rtc_driver);
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}
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module_init(at91_rtc_init);
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module_exit(at91_rtc_exit);
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MODULE_AUTHOR("Rick Bronson");
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MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:at91_rtc");
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