Commit 5a5b614b authored by Marek Szyprowski's avatar Marek Szyprowski Committed by Alexandre Belloni
Browse files

rtc: s3c: Rewrite clock handling 



s3c_rtc_enable/disable_clk() functions were designed to be called multiple
times without reference counting, because they were initially only used in
alarm setting/clearing functions, which can be called both when alarm is
already set or not. Later however, calls to those functions have been added to
other places in the driver - like time and /proc reading callbacks, what
results in broken alarm if any of such events happens after the alarm has
been set. Fix this by simplifying s3c_rtc_enable/disable_clk() functions
to rely on proper reference counting in clock core and move alarm enable
counter to s3c_rtc_setaie() function.

Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent f724c6be

drivers/rtc/rtc-s3c.c

+31 −43
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ struct s3c_rtc { 
	void __iomem *base;

	struct clk *rtc_clk;

	struct clk *rtc_src_clk;

	bool clk_disabled;

	bool alarm_enabled;



	const struct s3c_rtc_data *data;
@@ -47,7 +47,7 @@ struct s3c_rtc { 
	int irq_tick;



	spinlock_t pie_lock;

	spinlock_t alarm_clk_lock;

	spinlock_t alarm_lock;



	int ticnt_save;

	int ticnt_en_save;
@@ -70,44 +70,27 @@ struct s3c_rtc_data { 


static int s3c_rtc_enable_clk(struct s3c_rtc *info)

{

	unsigned long irq_flags;

	int ret = 0;



	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);

	int ret;



	if (info->clk_disabled) {

	ret = clk_enable(info->rtc_clk);

	if (ret)

			goto out;

		return ret;



	if (info->data->needs_src_clk) {

		ret = clk_enable(info->rtc_src_clk);

		if (ret) {

			clk_disable(info->rtc_clk);

				goto out;

			}

			return ret;

		}

		info->clk_disabled = false;

	}



out:

	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);



	return ret;

	return 0;

}



static void s3c_rtc_disable_clk(struct s3c_rtc *info)

{

	unsigned long irq_flags;



	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);

	if (!info->clk_disabled) {

	if (info->data->needs_src_clk)

		clk_disable(info->rtc_src_clk);

	clk_disable(info->rtc_clk);

		info->clk_disabled = true;

	}

	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);

}



/* IRQ Handlers */
@@ -135,6 +118,7 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 
static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)

{

	struct s3c_rtc *info = dev_get_drvdata(dev);

	unsigned long flags;

	unsigned int tmp;

	int ret;
@@ -151,17 +135,19 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) 


	writeb(tmp, info->base + S3C2410_RTCALM);



	s3c_rtc_disable_clk(info);

	spin_lock_irqsave(&info->alarm_lock, flags);



	if (enabled) {

	if (info->alarm_enabled && !enabled)

		s3c_rtc_disable_clk(info);

	else if (!info->alarm_enabled && enabled)

		ret = s3c_rtc_enable_clk(info);

		if (ret)

			return ret;

	} else {



	info->alarm_enabled = enabled;

	spin_unlock_irqrestore(&info->alarm_lock, flags);



	s3c_rtc_disable_clk(info);

	}



	return 0;

	return ret;

}



/* Set RTC frequency */
@@ -357,10 +343,10 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 


	writeb(alrm_en, info->base + S3C2410_RTCALM);



	s3c_rtc_disable_clk(info);



	s3c_rtc_setaie(dev, alrm->enabled);



	s3c_rtc_disable_clk(info);



	return 0;

}
@@ -491,7 +477,7 @@ static int s3c_rtc_probe(struct platform_device *pdev) 
		return -EINVAL;

	}

	spin_lock_init(&info->pie_lock);

	spin_lock_init(&info->alarm_clk_lock);

	spin_lock_init(&info->alarm_lock);



	platform_set_drvdata(pdev, info);
@@ -591,6 +577,8 @@ static int s3c_rtc_probe(struct platform_device *pdev) 


	s3c_rtc_setfreq(info, 1);



	s3c_rtc_disable_clk(info);



	return 0;



err_nortc: