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ARM: 6455/2: Better use of the RTC framework for sa11xx. 

This patch uses the RTC framework to treat some common ioctl.

In particular, it fixes the behaviour of rtc_irq_set_freq(), which did
not work as expected because the timer was not beeing retriggered.

Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
hifive-unleashed-5.1
Marcelo Roberto Jimenez 2010-12-16 21:31:32 +01:00 committed by Russell King
parent 47bb3b31ab
commit d2ccb52d88
1 changed files with 74 additions and 24 deletions
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98
drivers/rtc/rtc-sa1100.c
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@ -42,7 +42,7 @@
#define RTC_DEF_DIVIDER (32768 - 1)
#define RTC_DEF_TRIM 0
static unsigned long rtc_freq = 1024;
static const unsigned long RTC_FREQ = 1024;
static unsigned long timer_freq;
static struct rtc_time rtc_alarm;
static DEFINE_SPINLOCK(sa1100_rtc_lock);
@ -156,8 +156,58 @@ static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
static int sa1100_irq_set_freq(struct device *dev, int freq)
{
if (freq < 1 || freq > timer_freq) {
return -EINVAL;
} else {
struct rtc_device *rtc = (struct rtc_device *)dev;
rtc->irq_freq = freq;
return 0;
}
}
static int rtc_timer1_count;
static int sa1100_irq_set_state(struct device *dev, int enabled)
{
spin_lock_irq(&sa1100_rtc_lock);
if (enabled) {
struct rtc_device *rtc = (struct rtc_device *)dev;
OSMR1 = timer_freq / rtc->irq_freq + OSCR;
OIER |= OIER_E1;
rtc_timer1_count = 1;
} else {
OIER &= ~OIER_E1;
}
spin_unlock_irq(&sa1100_rtc_lock);
return 0;
}
static inline int sa1100_timer1_retrigger(struct rtc_device *rtc)
{
unsigned long diff;
unsigned long period = timer_freq / rtc->irq_freq;
spin_lock_irq(&sa1100_rtc_lock);
do {
OSMR1 += period;
diff = OSMR1 - OSCR;
/* If OSCR > OSMR1, diff is a very large number (unsigned
* math). This means we have a lost interrupt. */
} while (diff > period);
OIER |= OIER_E1;
spin_unlock_irq(&sa1100_rtc_lock);
return 0;
}
static irqreturn_t timer1_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = to_platform_device(dev_id);
@ -175,7 +225,11 @@ static irqreturn_t timer1_interrupt(int irq, void *dev_id)
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)));
rtc_timer1_count =
(rtc->irq_freq * ((1 << 30) / (timer_freq >> 2)));
/* retrigger. */
sa1100_timer1_retrigger(rtc);
return IRQ_HANDLED;
}
@ -183,8 +237,10 @@ static irqreturn_t timer1_interrupt(int irq, void *dev_id)
static int sa1100_rtc_read_callback(struct device *dev, int data)
{
if (data & RTC_PF) {
struct rtc_device *rtc = (struct rtc_device *)dev;
/* interpolate missed periods and set match for the next */
unsigned long period = timer_freq / rtc_freq;
unsigned long period = timer_freq / rtc->irq_freq;
unsigned long oscr = OSCR;
unsigned long osmr1 = OSMR1;
unsigned long missed = (oscr - osmr1)/period;
@ -207,6 +263,7 @@ static int sa1100_rtc_read_callback(struct device *dev, int data)
static int sa1100_rtc_open(struct device *dev)
{
int ret;
struct rtc_device *rtc = (struct rtc_device *)dev;
ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
"rtc 1Hz", dev);
@ -226,6 +283,9 @@ static int sa1100_rtc_open(struct device *dev)
dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1);
goto fail_pi;
}
rtc->max_user_freq = RTC_FREQ;
sa1100_irq_set_freq(dev, RTC_FREQ);
return 0;
fail_pi:
@ -274,25 +334,6 @@ static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
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;
}
@ -344,12 +385,14 @@ static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
{
struct rtc_device *rtc = (struct rtc_device *)dev;
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, "periodic_freq\t: %d\n", rtc->irq_freq);
seq_printf(seq, "RTSR\t\t: 0x%08x\n", (u32)RTSR);
return 0;
@ -365,6 +408,8 @@ static const struct rtc_class_ops sa1100_rtc_ops = {
.read_alarm = sa1100_rtc_read_alarm,
.set_alarm = sa1100_rtc_set_alarm,
.proc = sa1100_rtc_proc,
.irq_set_freq = sa1100_irq_set_freq,
.irq_set_state = sa1100_irq_set_state,
};
static int sa1100_rtc_probe(struct platform_device *pdev)
@ -391,13 +436,18 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, 1);
rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
THIS_MODULE);
THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
platform_set_drvdata(pdev, rtc);
/* Set the irq_freq */
/*TODO: Find out who is messing with this value after we initialize
* it here.*/
rtc->irq_freq = RTC_FREQ;
/* Fix for a nasty initialization problem the in SA11xx RTSR register.
* See also the comments in sa1100_rtc_interrupt().
*