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Commit d2ccb52d authored by Marcelo Roberto Jimenez's avatar Marcelo Roberto Jimenez Committed by Russell King
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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: default avatarMarcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 47bb3b31

drivers/rtc/rtc-sa1100.c

+74 −24
Original line number Diff line number Diff line
@@ -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)
@@ -398,6 +443,11 @@ static int sa1100_rtc_probe(struct platform_device *pdev) 


	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().

	 *