557 lines
14 KiB
C
557 lines
14 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/bcd.h>
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#include <linux/clk.h>
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#include <linux/completion.h>
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#include <linux/interrupt.h>
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#include <linux/ioctl.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/rtc.h>
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#include <linux/spinlock.h>
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#include <linux/suspend.h>
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#include <linux/time.h>
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#include <linux/uaccess.h>
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#include "rtc-at91rm9200.h"
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#define at91_rtc_read(field) \
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readl_relaxed(at91_rtc_regs + field)
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#define at91_rtc_write(field, val) \
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writel_relaxed((val), at91_rtc_regs + field)
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struct at91_rtc_config {
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bool use_shadow_imr;
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};
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static const struct at91_rtc_config *at91_rtc_config;
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static DECLARE_COMPLETION(at91_rtc_updated);
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static DECLARE_COMPLETION(at91_rtc_upd_rdy);
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static void __iomem *at91_rtc_regs;
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static int irq;
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static DEFINE_SPINLOCK(at91_rtc_lock);
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static u32 at91_rtc_shadow_imr;
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static bool suspended;
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static DEFINE_SPINLOCK(suspended_lock);
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static unsigned long cached_events;
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static u32 at91_rtc_imr;
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static struct clk *sclk;
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static void at91_rtc_write_ier(u32 mask)
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{
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unsigned long flags;
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spin_lock_irqsave(&at91_rtc_lock, flags);
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at91_rtc_shadow_imr |= mask;
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at91_rtc_write(AT91_RTC_IER, mask);
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spin_unlock_irqrestore(&at91_rtc_lock, flags);
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}
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static void at91_rtc_write_idr(u32 mask)
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{
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unsigned long flags;
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spin_lock_irqsave(&at91_rtc_lock, flags);
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at91_rtc_write(AT91_RTC_IDR, mask);
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/*
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* Register read back (of any RTC-register) needed to make sure
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* IDR-register write has reached the peripheral before updating
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* shadow mask.
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*
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* Note that there is still a possibility that the mask is updated
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* before interrupts have actually been disabled in hardware. The only
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* way to be certain would be to poll the IMR-register, which is is
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* the very register we are trying to emulate. The register read back
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* is a reasonable heuristic.
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*/
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at91_rtc_read(AT91_RTC_SR);
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at91_rtc_shadow_imr &= ~mask;
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spin_unlock_irqrestore(&at91_rtc_lock, flags);
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}
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static u32 at91_rtc_read_imr(void)
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{
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unsigned long flags;
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u32 mask;
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if (at91_rtc_config->use_shadow_imr) {
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spin_lock_irqsave(&at91_rtc_lock, flags);
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mask = at91_rtc_shadow_imr;
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spin_unlock_irqrestore(&at91_rtc_lock, flags);
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} else {
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mask = at91_rtc_read(AT91_RTC_IMR);
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}
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return mask;
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}
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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_rtc_read(timereg);
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date = at91_rtc_read(calreg);
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} while ((time != at91_rtc_read(timereg)) ||
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(date != at91_rtc_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.
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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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dev_dbg(dev, "%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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dev_dbg(dev, "%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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wait_for_completion(&at91_rtc_upd_rdy);
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/* Stop Time/Calendar from counting */
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cr = at91_rtc_read(AT91_RTC_CR);
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at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
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at91_rtc_write_ier(AT91_RTC_ACKUPD);
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wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
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at91_rtc_write_idr(AT91_RTC_ACKUPD);
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at91_rtc_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_rtc_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_rtc_read(AT91_RTC_CR);
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at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
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at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
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at91_rtc_write_ier(AT91_RTC_SECEV);
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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_year = -1;
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alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
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? 1 : 0;
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dev_dbg(dev, "%s(): %02d-%02d %02d:%02d:%02d %sabled\n", __func__,
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tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec,
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alrm->enabled ? "en" : "dis");
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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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tm.tm_mon = alrm->time.tm_mon;
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tm.tm_mday = alrm->time.tm_mday;
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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_rtc_write_idr(AT91_RTC_ALARM);
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at91_rtc_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_rtc_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_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
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at91_rtc_write_ier(AT91_RTC_ALARM);
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}
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dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
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tm.tm_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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static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
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if (enabled) {
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at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
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at91_rtc_write_ier(AT91_RTC_ALARM);
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} else
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at91_rtc_write_idr(AT91_RTC_ALARM);
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return 0;
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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_rtc_read_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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int ret = IRQ_NONE;
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spin_lock(&suspended_lock);
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rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_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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complete(&at91_rtc_upd_rdy);
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at91_rtc_write_idr(AT91_RTC_SECEV);
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}
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if (rtsr & AT91_RTC_ACKUPD)
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complete(&at91_rtc_updated);
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at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
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if (!suspended) {
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rtc_update_irq(rtc, 1, events);
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dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
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__func__, events >> 8, events & 0x000000FF);
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} else {
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cached_events |= events;
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at91_rtc_write_idr(at91_rtc_imr);
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pm_system_wakeup();
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}
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ret = IRQ_HANDLED;
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}
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spin_unlock(&suspended_lock);
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return ret;
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}
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static const struct at91_rtc_config at91rm9200_config = {
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};
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static const struct at91_rtc_config at91sam9x5_config = {
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.use_shadow_imr = true,
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};
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#ifdef CONFIG_OF
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static const struct of_device_id at91_rtc_dt_ids[] = {
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{
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.compatible = "atmel,at91rm9200-rtc",
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.data = &at91rm9200_config,
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}, {
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.compatible = "atmel,at91sam9x5-rtc",
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.data = &at91sam9x5_config,
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}, {
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/* sentinel */
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}
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};
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MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
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#endif
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static const struct at91_rtc_config *
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at91_rtc_get_config(struct platform_device *pdev)
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{
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const struct of_device_id *match;
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if (pdev->dev.of_node) {
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match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
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if (!match)
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return NULL;
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return (const struct at91_rtc_config *)match->data;
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}
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return &at91rm9200_config;
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}
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static const struct rtc_class_ops at91_rtc_ops = {
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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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.alarm_irq_enable = at91_rtc_alarm_irq_enable,
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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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struct resource *regs;
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int ret = 0;
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at91_rtc_config = at91_rtc_get_config(pdev);
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if (!at91_rtc_config)
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return -ENODEV;
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regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!regs) {
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dev_err(&pdev->dev, "no mmio resource defined\n");
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return -ENXIO;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(&pdev->dev, "no irq resource defined\n");
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return -ENXIO;
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}
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at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
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resource_size(regs));
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if (!at91_rtc_regs) {
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dev_err(&pdev->dev, "failed to map registers, aborting.\n");
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return -ENOMEM;
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}
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rtc = devm_rtc_allocate_device(&pdev->dev);
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if (IS_ERR(rtc))
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return PTR_ERR(rtc);
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platform_set_drvdata(pdev, rtc);
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sclk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(sclk))
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return PTR_ERR(sclk);
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ret = clk_prepare_enable(sclk);
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if (ret) {
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dev_err(&pdev->dev, "Could not enable slow clock\n");
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return ret;
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}
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at91_rtc_write(AT91_RTC_CR, 0);
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at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
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/* Disable all interrupts */
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at91_rtc_write_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 = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
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IRQF_SHARED | IRQF_COND_SUSPEND,
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"at91_rtc", pdev);
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if (ret) {
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dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
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goto err_clk;
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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->ops = &at91_rtc_ops;
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ret = rtc_register_device(rtc);
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if (ret)
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goto err_clk;
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/* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
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* completion.
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*/
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at91_rtc_write_ier(AT91_RTC_SECEV);
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dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
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return 0;
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err_clk:
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clk_disable_unprepare(sclk);
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return ret;
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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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/* Disable all interrupts */
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at91_rtc_write_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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clk_disable_unprepare(sclk);
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return 0;
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}
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static void at91_rtc_shutdown(struct platform_device *pdev)
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{
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/* Disable all interrupts */
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at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
|
|
AT91_RTC_SECEV | AT91_RTC_TIMEV |
|
|
AT91_RTC_CALEV);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
|
|
/* AT91RM9200 RTC Power management control */
|
|
|
|
static int at91_rtc_suspend(struct device *dev)
|
|
{
|
|
/* this IRQ is shared with DBGU and other hardware which isn't
|
|
* necessarily doing PM like we are...
|
|
*/
|
|
at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
|
|
|
|
at91_rtc_imr = at91_rtc_read_imr()
|
|
& (AT91_RTC_ALARM|AT91_RTC_SECEV);
|
|
if (at91_rtc_imr) {
|
|
if (device_may_wakeup(dev)) {
|
|
unsigned long flags;
|
|
|
|
enable_irq_wake(irq);
|
|
|
|
spin_lock_irqsave(&suspended_lock, flags);
|
|
suspended = true;
|
|
spin_unlock_irqrestore(&suspended_lock, flags);
|
|
} else {
|
|
at91_rtc_write_idr(at91_rtc_imr);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int at91_rtc_resume(struct device *dev)
|
|
{
|
|
struct rtc_device *rtc = dev_get_drvdata(dev);
|
|
|
|
if (at91_rtc_imr) {
|
|
if (device_may_wakeup(dev)) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&suspended_lock, flags);
|
|
|
|
if (cached_events) {
|
|
rtc_update_irq(rtc, 1, cached_events);
|
|
cached_events = 0;
|
|
}
|
|
|
|
suspended = false;
|
|
spin_unlock_irqrestore(&suspended_lock, flags);
|
|
|
|
disable_irq_wake(irq);
|
|
}
|
|
at91_rtc_write_ier(at91_rtc_imr);
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
|
|
|
|
static struct platform_driver at91_rtc_driver = {
|
|
.remove = __exit_p(at91_rtc_remove),
|
|
.shutdown = at91_rtc_shutdown,
|
|
.driver = {
|
|
.name = "at91_rtc",
|
|
.pm = &at91_rtc_pm_ops,
|
|
.of_match_table = of_match_ptr(at91_rtc_dt_ids),
|
|
},
|
|
};
|
|
|
|
module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
|
|
|
|
MODULE_AUTHOR("Rick Bronson");
|
|
MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:at91_rtc");
|