441 lines
10 KiB
C
441 lines
10 KiB
C
/*
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* Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
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*
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* Copyright (c) 2000 Nils Faerber
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*
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* Based on rtc.c by Paul Gortmaker
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*
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* Original Driver by Nils Faerber <nils@kernelconcepts.de>
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*
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* Modifications from:
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* CIH <cih@coventive.com>
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* Nicolas Pitre <nico@cam.org>
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* Andrew Christian <andrew.christian@hp.com>
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*
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* Converted to the RTC subsystem and Driver Model
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* by Richard Purdie <rpurdie@rpsys.net>
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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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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/rtc.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/interrupt.h>
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#include <linux/string.h>
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#include <linux/pm.h>
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#include <linux/bitops.h>
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#include <mach/hardware.h>
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#include <asm/irq.h>
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#ifdef CONFIG_ARCH_PXA
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#include <mach/regs-rtc.h>
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#include <mach/regs-ost.h>
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#endif
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#define RTC_DEF_DIVIDER 32768 - 1
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#define RTC_DEF_TRIM 0
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static unsigned long rtc_freq = 1024;
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static unsigned long timer_freq;
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static struct rtc_time rtc_alarm;
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static DEFINE_SPINLOCK(sa1100_rtc_lock);
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static inline int rtc_periodic_alarm(struct rtc_time *tm)
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{
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return (tm->tm_year == -1) ||
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((unsigned)tm->tm_mon >= 12) ||
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((unsigned)(tm->tm_mday - 1) >= 31) ||
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((unsigned)tm->tm_hour > 23) ||
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((unsigned)tm->tm_min > 59) ||
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((unsigned)tm->tm_sec > 59);
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}
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/*
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* Calculate the next alarm time given the requested alarm time mask
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* and the current time.
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*/
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static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
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{
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unsigned long next_time;
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unsigned long now_time;
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next->tm_year = now->tm_year;
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next->tm_mon = now->tm_mon;
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next->tm_mday = now->tm_mday;
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next->tm_hour = alrm->tm_hour;
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next->tm_min = alrm->tm_min;
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next->tm_sec = alrm->tm_sec;
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rtc_tm_to_time(now, &now_time);
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rtc_tm_to_time(next, &next_time);
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if (next_time < now_time) {
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/* Advance one day */
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next_time += 60 * 60 * 24;
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rtc_time_to_tm(next_time, next);
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}
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}
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static int rtc_update_alarm(struct rtc_time *alrm)
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{
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struct rtc_time alarm_tm, now_tm;
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unsigned long now, time;
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int ret;
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do {
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now = RCNR;
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rtc_time_to_tm(now, &now_tm);
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rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
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ret = rtc_tm_to_time(&alarm_tm, &time);
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if (ret != 0)
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break;
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RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
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RTAR = time;
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} while (now != RCNR);
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return ret;
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}
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static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
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{
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struct platform_device *pdev = to_platform_device(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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spin_lock(&sa1100_rtc_lock);
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rtsr = RTSR;
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/* clear interrupt sources */
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RTSR = 0;
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RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
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/* clear alarm interrupt if it has occurred */
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if (rtsr & RTSR_AL)
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rtsr &= ~RTSR_ALE;
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RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
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/* update irq data & counter */
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if (rtsr & RTSR_AL)
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events |= RTC_AF | RTC_IRQF;
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if (rtsr & RTSR_HZ)
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events |= RTC_UF | RTC_IRQF;
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rtc_update_irq(rtc, 1, events);
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if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm))
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rtc_update_alarm(&rtc_alarm);
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spin_unlock(&sa1100_rtc_lock);
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return IRQ_HANDLED;
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}
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static int rtc_timer1_count;
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static irqreturn_t timer1_interrupt(int irq, void *dev_id)
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{
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struct platform_device *pdev = to_platform_device(dev_id);
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struct rtc_device *rtc = platform_get_drvdata(pdev);
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/*
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* If we match for the first time, rtc_timer1_count will be 1.
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* Otherwise, we wrapped around (very unlikely but
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* still possible) so compute the amount of missed periods.
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* The match reg is updated only when the data is actually retrieved
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* to avoid unnecessary interrupts.
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*/
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OSSR = OSSR_M1; /* clear match on timer1 */
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rtc_update_irq(rtc, rtc_timer1_count, RTC_PF | RTC_IRQF);
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if (rtc_timer1_count == 1)
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rtc_timer1_count = (rtc_freq * ((1 << 30) / (timer_freq >> 2)));
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return IRQ_HANDLED;
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}
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static int sa1100_rtc_read_callback(struct device *dev, int data)
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{
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if (data & RTC_PF) {
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/* interpolate missed periods and set match for the next */
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unsigned long period = timer_freq / rtc_freq;
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unsigned long oscr = OSCR;
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unsigned long osmr1 = OSMR1;
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unsigned long missed = (oscr - osmr1)/period;
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data += missed << 8;
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OSSR = OSSR_M1; /* clear match on timer 1 */
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OSMR1 = osmr1 + (missed + 1)*period;
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/* Ensure we didn't miss another match in the mean time.
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* Here we compare (match - OSCR) 8 instead of 0 --
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* see comment in pxa_timer_interrupt() for explanation.
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*/
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while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) {
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data += 0x100;
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OSSR = OSSR_M1; /* clear match on timer 1 */
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OSMR1 = osmr1 + period;
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}
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}
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return data;
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}
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static int sa1100_rtc_open(struct device *dev)
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{
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int ret;
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ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
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"rtc 1Hz", dev);
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if (ret) {
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dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz);
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goto fail_ui;
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}
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ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED,
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"rtc Alrm", dev);
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if (ret) {
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dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
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goto fail_ai;
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}
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ret = request_irq(IRQ_OST1, timer1_interrupt, IRQF_DISABLED,
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"rtc timer", dev);
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if (ret) {
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dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1);
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goto fail_pi;
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}
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return 0;
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fail_pi:
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free_irq(IRQ_RTCAlrm, dev);
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fail_ai:
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free_irq(IRQ_RTC1Hz, dev);
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fail_ui:
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return ret;
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}
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static void sa1100_rtc_release(struct device *dev)
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{
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spin_lock_irq(&sa1100_rtc_lock);
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RTSR = 0;
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OIER &= ~OIER_E1;
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OSSR = OSSR_M1;
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spin_unlock_irq(&sa1100_rtc_lock);
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free_irq(IRQ_OST1, dev);
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free_irq(IRQ_RTCAlrm, dev);
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free_irq(IRQ_RTC1Hz, dev);
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}
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static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
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unsigned long arg)
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{
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switch(cmd) {
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case RTC_AIE_OFF:
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spin_lock_irq(&sa1100_rtc_lock);
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RTSR &= ~RTSR_ALE;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_AIE_ON:
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spin_lock_irq(&sa1100_rtc_lock);
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RTSR |= RTSR_ALE;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_UIE_OFF:
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spin_lock_irq(&sa1100_rtc_lock);
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RTSR &= ~RTSR_HZE;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_UIE_ON:
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spin_lock_irq(&sa1100_rtc_lock);
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RTSR |= RTSR_HZE;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_PIE_OFF:
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spin_lock_irq(&sa1100_rtc_lock);
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OIER &= ~OIER_E1;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_PIE_ON:
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spin_lock_irq(&sa1100_rtc_lock);
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OSMR1 = timer_freq / rtc_freq + OSCR;
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OIER |= OIER_E1;
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rtc_timer1_count = 1;
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spin_unlock_irq(&sa1100_rtc_lock);
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return 0;
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case RTC_IRQP_READ:
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return put_user(rtc_freq, (unsigned long *)arg);
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case RTC_IRQP_SET:
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if (arg < 1 || arg > timer_freq)
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return -EINVAL;
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rtc_freq = arg;
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return 0;
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}
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return -ENOIOCTLCMD;
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}
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static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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rtc_time_to_tm(RCNR, tm);
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return 0;
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}
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static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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unsigned long time;
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int ret;
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ret = rtc_tm_to_time(tm, &time);
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if (ret == 0)
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RCNR = time;
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return ret;
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}
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static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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u32 rtsr;
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memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time));
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rtsr = RTSR;
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alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
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alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
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return 0;
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}
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static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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int ret;
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spin_lock_irq(&sa1100_rtc_lock);
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ret = rtc_update_alarm(&alrm->time);
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if (ret == 0) {
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if (alrm->enabled)
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RTSR |= RTSR_ALE;
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else
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RTSR &= ~RTSR_ALE;
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}
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spin_unlock_irq(&sa1100_rtc_lock);
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return ret;
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}
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static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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seq_printf(seq, "trim/divider\t: 0x%08x\n", (u32) RTTR);
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seq_printf(seq, "update_IRQ\t: %s\n",
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(RTSR & RTSR_HZE) ? "yes" : "no");
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seq_printf(seq, "periodic_IRQ\t: %s\n",
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(OIER & OIER_E1) ? "yes" : "no");
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seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq);
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return 0;
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}
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static const struct rtc_class_ops sa1100_rtc_ops = {
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.open = sa1100_rtc_open,
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.read_callback = sa1100_rtc_read_callback,
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.release = sa1100_rtc_release,
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.ioctl = sa1100_rtc_ioctl,
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.read_time = sa1100_rtc_read_time,
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.set_time = sa1100_rtc_set_time,
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.read_alarm = sa1100_rtc_read_alarm,
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.set_alarm = sa1100_rtc_set_alarm,
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.proc = sa1100_rtc_proc,
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};
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static int sa1100_rtc_probe(struct platform_device *pdev)
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{
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struct rtc_device *rtc;
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timer_freq = get_clock_tick_rate();
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/*
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* According to the manual we should be able to let RTTR be zero
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* and then a default diviser for a 32.768KHz clock is used.
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* Apparently this doesn't work, at least for my SA1110 rev 5.
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* If the clock divider is uninitialized then reset it to the
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* default value to get the 1Hz clock.
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*/
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if (RTTR == 0) {
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RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
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dev_warn(&pdev->dev, "warning: initializing default clock divider/trim value\n");
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/* The current RTC value probably doesn't make sense either */
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RCNR = 0;
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}
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device_init_wakeup(&pdev->dev, 1);
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rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
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THIS_MODULE);
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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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return 0;
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}
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static int sa1100_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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if (rtc)
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rtc_device_unregister(rtc);
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return 0;
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}
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#ifdef CONFIG_PM
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static int sa1100_rtc_suspend(struct platform_device *pdev, pm_message_t state)
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{
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if (device_may_wakeup(&pdev->dev))
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enable_irq_wake(IRQ_RTCAlrm);
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return 0;
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}
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static int sa1100_rtc_resume(struct platform_device *pdev)
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{
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if (device_may_wakeup(&pdev->dev))
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disable_irq_wake(IRQ_RTCAlrm);
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return 0;
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}
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#else
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#define sa1100_rtc_suspend NULL
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#define sa1100_rtc_resume NULL
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#endif
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static struct platform_driver sa1100_rtc_driver = {
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.probe = sa1100_rtc_probe,
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.remove = sa1100_rtc_remove,
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.suspend = sa1100_rtc_suspend,
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.resume = sa1100_rtc_resume,
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.driver = {
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.name = "sa1100-rtc",
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},
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};
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static int __init sa1100_rtc_init(void)
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{
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return platform_driver_register(&sa1100_rtc_driver);
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}
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static void __exit sa1100_rtc_exit(void)
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{
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platform_driver_unregister(&sa1100_rtc_driver);
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}
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module_init(sa1100_rtc_init);
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module_exit(sa1100_rtc_exit);
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MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
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MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:sa1100-rtc");
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