Commit cefe4fbb authored by Donggeun Kim's avatar Donggeun Kim Committed by Linus Torvalds
Browse files

drivers/rtc/rtc-s3c.c: support clock gating 



Add support for clock gating.  Power consumption can be reduced by setting
rtc_clk disabled state except for when RTC related registers are accessed.

Signed-off-by: default avatarDonggeun Kim <dg77.kim@samsung.com>
Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: default avatarKyungMin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ben Dooks <ben@fluff.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 955dbea3

drivers/rtc/rtc-s3c.c

+26 −1
Original line number Diff line number Diff line
@@ -57,11 +57,13 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 
{

	struct rtc_device *rdev = id;



	clk_enable(rtc_clk);

	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);



	if (s3c_rtc_cpu_type == TYPE_S3C64XX)

		writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);



	clk_disable(rtc_clk);

	return IRQ_HANDLED;

}
@@ -69,11 +71,13 @@ static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 
{

	struct rtc_device *rdev = id;



	clk_enable(rtc_clk);

	rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);



	if (s3c_rtc_cpu_type == TYPE_S3C64XX)

		writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);



	clk_disable(rtc_clk);

	return IRQ_HANDLED;

}
@@ -84,12 +88,14 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) 


	pr_debug("%s: aie=%d\n", __func__, enabled);



	clk_enable(rtc_clk);

	tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;



	if (enabled)

		tmp |= S3C2410_RTCALM_ALMEN;



	writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);

	clk_disable(rtc_clk);



	return 0;

}
@@ -103,6 +109,7 @@ static int s3c_rtc_setfreq(struct device *dev, int freq) 
	if (!is_power_of_2(freq))

		return -EINVAL;



	clk_enable(rtc_clk);

	spin_lock_irq(&s3c_rtc_pie_lock);



	if (s3c_rtc_cpu_type == TYPE_S3C2410) {
@@ -114,6 +121,7 @@ static int s3c_rtc_setfreq(struct device *dev, int freq) 


	writel(tmp, s3c_rtc_base + S3C2410_TICNT);

	spin_unlock_irq(&s3c_rtc_pie_lock);

	clk_disable(rtc_clk);



	return 0;

}
@@ -125,6 +133,7 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 
	unsigned int have_retried = 0;

	void __iomem *base = s3c_rtc_base;



	clk_enable(rtc_clk);

 retry_get_time:

	rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);

	rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
@@ -157,6 +166,7 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 
	rtc_tm->tm_year += 100;

	rtc_tm->tm_mon -= 1;



	clk_disable(rtc_clk);

	return rtc_valid_tm(rtc_tm);

}
@@ -165,6 +175,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) 
	void __iomem *base = s3c_rtc_base;

	int year = tm->tm_year - 100;



	clk_enable(rtc_clk);

	pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",

		 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,

		 tm->tm_hour, tm->tm_min, tm->tm_sec);
@@ -182,6 +193,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) 
	writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);

	writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);

	writeb(bin2bcd(year), base + S3C2410_RTCYEAR);

	clk_disable(rtc_clk);



	return 0;

}
@@ -192,6 +204,7 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) 
	void __iomem *base = s3c_rtc_base;

	unsigned int alm_en;



	clk_enable(rtc_clk);

	alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);

	alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);

	alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
@@ -243,6 +256,7 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) 
	else

		alm_tm->tm_year = -1;



	clk_disable(rtc_clk);

	return 0;

}
@@ -252,6 +266,7 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 
	void __iomem *base = s3c_rtc_base;

	unsigned int alrm_en;



	clk_enable(rtc_clk);

	pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",

		 alrm->enabled,

		 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
@@ -282,6 +297,7 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 


	s3c_rtc_setaie(dev, alrm->enabled);



	clk_disable(rtc_clk);

	return 0;

}
@@ -289,6 +305,7 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 
{

	unsigned int ticnt;



	clk_enable(rtc_clk);

	if (s3c_rtc_cpu_type == TYPE_S3C64XX) {

		ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);

		ticnt &= S3C64XX_RTCCON_TICEN;
@@ -298,6 +315,7 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 
	}



	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");

	clk_disable(rtc_clk);

	return 0;

}
@@ -360,6 +378,7 @@ static void s3c_rtc_enable(struct platform_device *pdev, int en) 
	if (s3c_rtc_base == NULL)

		return;



	clk_enable(rtc_clk);

	if (!en) {

		tmp = readw(base + S3C2410_RTCCON);

		if (s3c_rtc_cpu_type == TYPE_S3C64XX)
@@ -399,6 +418,7 @@ static void s3c_rtc_enable(struct platform_device *pdev, int en) 
				base + S3C2410_RTCCON);

		}

	}

	clk_disable(rtc_clk);

}



static int __devexit s3c_rtc_remove(struct platform_device *dev)
@@ -410,7 +430,6 @@ static int __devexit s3c_rtc_remove(struct platform_device *dev) 


	s3c_rtc_setaie(&dev->dev, 0);



	clk_disable(rtc_clk);

	clk_put(rtc_clk);

	rtc_clk = NULL;
@@ -530,6 +549,8 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev) 


	s3c_rtc_setfreq(&pdev->dev, 1);



	clk_disable(rtc_clk);



	return 0;



 err_nortc:
@@ -555,6 +576,7 @@ static int ticnt_save, ticnt_en_save; 


static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)

{

	clk_enable(rtc_clk);

	/* save TICNT for anyone using periodic interrupts */

	ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);

	if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
@@ -569,6 +591,7 @@ static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 
		else

			dev_err(&pdev->dev, "enable_irq_wake failed\n");

	}

	clk_disable(rtc_clk);



	return 0;

}
@@ -577,6 +600,7 @@ static int s3c_rtc_resume(struct platform_device *pdev) 
{

	unsigned int tmp;



	clk_enable(rtc_clk);

	s3c_rtc_enable(pdev, 1);

	writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);

	if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
@@ -588,6 +612,7 @@ static int s3c_rtc_resume(struct platform_device *pdev) 
		disable_irq_wake(s3c_rtc_alarmno);

		wake_en = false;

	}

	clk_disable(rtc_clk);



	return 0;

}

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