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linux/drivers/rtc/rtc-sa1100.c
Russell King 6bc54e6992 [ARM] pxa/sa1100: replace wakeup support 
Replace wakeup support using the alarm via the SA1100 RTC driver on
SA1100 and PXA platforms.  This allows RTC alarm wakeup to be enabled
via sysfs using the conventional attributes.

Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-26 15:07:51 +00:00

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