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path: root/drivers/rtc/rtc-sa1100.c
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Diffstat (limited to 'drivers/rtc/rtc-sa1100.c')
-rw-r--r--drivers/rtc/rtc-sa1100.c399
1 files changed, 160 insertions, 239 deletions
diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index e4a44b64170..b6e1ca08c2c 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -23,100 +23,66 @@
#include <linux/platform_device.h>
#include <linux/module.h>
+#include <linux/clk.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
+#include <linux/slab.h>
#include <linux/string.h>
+#include <linux/of.h>
#include <linux/pm.h>
#include <linux/bitops.h>
+#include <linux/io.h>
#include <mach/hardware.h>
-#include <asm/irq.h>
+#include <mach/irqs.h>
-#ifdef CONFIG_ARCH_PXA
+#if defined(CONFIG_ARCH_PXA) || defined(CONFIG_ARCH_MMP)
#include <mach/regs-rtc.h>
-#include <mach/regs-ost.h>
#endif
-#define RTC_DEF_DIVIDER 32768 - 1
+#define RTC_DEF_DIVIDER (32768 - 1)
#define RTC_DEF_TRIM 0
-
-static unsigned long rtc_freq = 1024;
-static unsigned long timer_freq;
-static struct rtc_time rtc_alarm;
-static DEFINE_SPINLOCK(sa1100_rtc_lock);
-
-static inline int rtc_periodic_alarm(struct rtc_time *tm)
-{
- return (tm->tm_year == -1) ||
- ((unsigned)tm->tm_mon >= 12) ||
- ((unsigned)(tm->tm_mday - 1) >= 31) ||
- ((unsigned)tm->tm_hour > 23) ||
- ((unsigned)tm->tm_min > 59) ||
- ((unsigned)tm->tm_sec > 59);
-}
-
-/*
- * Calculate the next alarm time given the requested alarm time mask
- * and the current time.
- */
-static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
-{
- unsigned long next_time;
- unsigned long now_time;
-
- next->tm_year = now->tm_year;
- next->tm_mon = now->tm_mon;
- next->tm_mday = now->tm_mday;
- next->tm_hour = alrm->tm_hour;
- next->tm_min = alrm->tm_min;
- next->tm_sec = alrm->tm_sec;
-
- rtc_tm_to_time(now, &now_time);
- rtc_tm_to_time(next, &next_time);
-
- if (next_time < now_time) {
- /* Advance one day */
- next_time += 60 * 60 * 24;
- rtc_time_to_tm(next_time, next);
- }
-}
-
-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;
-}
+#define RTC_FREQ 1024
+
+struct sa1100_rtc {
+ spinlock_t lock;
+ int irq_1hz;
+ int irq_alarm;
+ struct rtc_device *rtc;
+ struct clk *clk;
+};
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);
+ struct sa1100_rtc *info = dev_get_drvdata(dev_id);
+ struct rtc_device *rtc = info->rtc;
unsigned int rtsr;
unsigned long events = 0;
- spin_lock(&sa1100_rtc_lock);
+ spin_lock(&info->lock);
rtsr = RTSR;
/* clear interrupt sources */
RTSR = 0;
- RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
+ /* Fix for a nasty initialization problem the in SA11xx RTSR register.
+ * See also the comments in sa1100_rtc_probe(). */
+ if (rtsr & (RTSR_ALE | RTSR_HZE)) {
+ /* This is the original code, before there was the if test
+ * above. This code does not clear interrupts that were not
+ * enabled. */
+ RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
+ } else {
+ /* For some reason, it is possible to enter this routine
+ * without interruptions enabled, it has been tested with
+ * several units (Bug in SA11xx chip?).
+ *
+ * This situation leads to an infinite "loop" of interrupt
+ * routine calling and as a result the processor seems to
+ * lock on its first call to open(). */
+ RTSR = RTSR_AL | RTSR_HZ;
+ }
/* clear alarm interrupt if it has occurred */
if (rtsr & RTSR_AL)
@@ -131,153 +97,62 @@ static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
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)));
+ spin_unlock(&info->lock);
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)
{
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
+ struct rtc_device *rtc = info->rtc;
int ret;
- ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
- "rtc 1Hz", dev);
+ ret = request_irq(info->irq_1hz, sa1100_rtc_interrupt, 0, "rtc 1Hz", dev);
if (ret) {
- dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz);
+ dev_err(dev, "IRQ %d already in use.\n", info->irq_1hz);
goto fail_ui;
}
- ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED,
- "rtc Alrm", dev);
+ ret = request_irq(info->irq_alarm, sa1100_rtc_interrupt, 0, "rtc Alrm", dev);
if (ret) {
- dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
+ dev_err(dev, "IRQ %d already in use.\n", info->irq_alarm);
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;
- }
+ rtc->max_user_freq = RTC_FREQ;
+ rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
+
return 0;
- fail_pi:
- free_irq(IRQ_RTCAlrm, dev);
fail_ai:
- free_irq(IRQ_RTC1Hz, dev);
+ free_irq(info->irq_1hz, dev);
fail_ui:
+ clk_disable_unprepare(info->clk);
return ret;
}
static void sa1100_rtc_release(struct device *dev)
{
- spin_lock_irq(&sa1100_rtc_lock);
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+ spin_lock_irq(&info->lock);
RTSR = 0;
- OIER &= ~OIER_E1;
- OSSR = OSSR_M1;
- spin_unlock_irq(&sa1100_rtc_lock);
+ spin_unlock_irq(&info->lock);
- free_irq(IRQ_OST1, dev);
- free_irq(IRQ_RTCAlrm, dev);
- free_irq(IRQ_RTC1Hz, dev);
+ free_irq(info->irq_alarm, dev);
+ free_irq(info->irq_1hz, dev);
}
-
-static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
- unsigned long arg)
+static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
- 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);
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+ spin_lock_irq(&info->lock);
+ if (enabled)
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;
+ else
+ RTSR &= ~RTSR_ALE;
+ spin_unlock_irq(&info->lock);
+ return 0;
}
static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
@@ -301,7 +176,6 @@ 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;
@@ -310,51 +184,72 @@ static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
+ unsigned long time;
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);
+ spin_lock_irq(&info->lock);
+ ret = rtc_tm_to_time(&alrm->time, &time);
+ if (ret != 0)
+ goto out;
+ RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
+ RTAR = time;
+ if (alrm->enabled)
+ RTSR |= RTSR_ALE;
+ else
+ RTSR &= ~RTSR_ALE;
+out:
+ spin_unlock_irq(&info->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);
+ seq_printf(seq, "trim/divider\t\t: 0x%08x\n", (u32) RTTR);
+ seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", (u32)RTSR);
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,
+ .alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
};
static int sa1100_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;
-
- timer_freq = get_clock_tick_rate();
-
+ struct sa1100_rtc *info;
+ int irq_1hz, irq_alarm, ret = 0;
+
+ irq_1hz = platform_get_irq_byname(pdev, "rtc 1Hz");
+ irq_alarm = platform_get_irq_byname(pdev, "rtc alarm");
+ if (irq_1hz < 0 || irq_alarm < 0)
+ return -ENODEV;
+
+ info = devm_kzalloc(&pdev->dev, sizeof(struct sa1100_rtc), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ info->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(info->clk)) {
+ dev_err(&pdev->dev, "failed to find rtc clock source\n");
+ return PTR_ERR(info->clk);
+ }
+ info->irq_1hz = irq_1hz;
+ info->irq_alarm = irq_alarm;
+ spin_lock_init(&info->lock);
+ platform_set_drvdata(pdev, info);
+
+ ret = clk_prepare_enable(info->clk);
+ if (ret)
+ return ret;
/*
* 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.
@@ -364,53 +259,91 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
*/
if (RTTR == 0) {
RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
- dev_warn(&pdev->dev, "warning: initializing default clock divider/trim value\n");
+ dev_warn(&pdev->dev, "warning: "
+ "initializing default clock divider/trim value\n");
/* The current RTC value probably doesn't make sense either */
RCNR = 0;
}
device_init_wakeup(&pdev->dev, 1);
- rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
- THIS_MODULE);
+ rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &sa1100_rtc_ops,
+ THIS_MODULE);
- if (IS_ERR(rtc))
- return PTR_ERR(rtc);
-
- platform_set_drvdata(pdev, rtc);
+ if (IS_ERR(rtc)) {
+ ret = PTR_ERR(rtc);
+ goto err_dev;
+ }
+ info->rtc = rtc;
+
+ /* Fix for a nasty initialization problem the in SA11xx RTSR register.
+ * See also the comments in sa1100_rtc_interrupt().
+ *
+ * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
+ * interrupt pending, even though interrupts were never enabled.
+ * In this case, this bit it must be reset before enabling
+ * interruptions to avoid a nonexistent interrupt to occur.
+ *
+ * In principle, the same problem would apply to bit 0, although it has
+ * never been observed to happen.
+ *
+ * This issue is addressed both here and in sa1100_rtc_interrupt().
+ * If the issue is not addressed here, in the times when the processor
+ * wakes up with the bit set there will be one spurious interrupt.
+ *
+ * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
+ * safe side, once the condition that lead to this strange
+ * initialization is unknown and could in principle happen during
+ * normal processing.
+ *
+ * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
+ * the corresponding bits in RTSR. */
+ RTSR = RTSR_AL | RTSR_HZ;
return 0;
+err_dev:
+ clk_disable_unprepare(info->clk);
+ return ret;
}
static int sa1100_rtc_remove(struct platform_device *pdev)
{
- struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct sa1100_rtc *info = platform_get_drvdata(pdev);
- if (rtc)
- rtc_device_unregister(rtc);
+ if (info)
+ clk_disable_unprepare(info->clk);
return 0;
}
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
static int sa1100_rtc_suspend(struct device *dev)
{
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
- enable_irq_wake(IRQ_RTCAlrm);
+ enable_irq_wake(info->irq_alarm);
return 0;
}
static int sa1100_rtc_resume(struct device *dev)
{
+ struct sa1100_rtc *info = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
- disable_irq_wake(IRQ_RTCAlrm);
+ disable_irq_wake(info->irq_alarm);
return 0;
}
+#endif
-static const struct dev_pm_ops sa1100_rtc_pm_ops = {
- .suspend = sa1100_rtc_suspend,
- .resume = sa1100_rtc_resume,
+static SIMPLE_DEV_PM_OPS(sa1100_rtc_pm_ops, sa1100_rtc_suspend,
+ sa1100_rtc_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id sa1100_rtc_dt_ids[] = {
+ { .compatible = "mrvl,sa1100-rtc", },
+ { .compatible = "mrvl,mmp-rtc", },
+ {}
};
+MODULE_DEVICE_TABLE(of, sa1100_rtc_dt_ids);
#endif
static struct platform_driver sa1100_rtc_driver = {
@@ -418,24 +351,12 @@ static struct platform_driver sa1100_rtc_driver = {
.remove = sa1100_rtc_remove,
.driver = {
.name = "sa1100-rtc",
-#ifdef CONFIG_PM
.pm = &sa1100_rtc_pm_ops,
-#endif
+ .of_match_table = of_match_ptr(sa1100_rtc_dt_ids),
},
};
-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_platform_driver(sa1100_rtc_driver);
MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 08:48:13 +0000