Commit 12de3621 authored by Alexander Shiyan's avatar Alexander Shiyan Committed by Linus Torvalds
Browse files

rtc: mc13xxx: change RTC validation scheme 



Datasheet says: "When the VSRTC voltage drops to the range of 0.9 - 0.8V,
the RTCPORB reset signal is generated and the contents of the RTC will
be reset.  <skip>.  To inform the processor that the contents of the RTC
are no longer valid due to the reset, a timer reset interrupt function
is implemented with the RTCRSTI bit." This patch makes the RTC valid by
default until RTCRST interrupt occurs.

Signed-off-by: default avatarAlexander Shiyan <shc_work@mail.ru>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fb1bd9a2

drivers/rtc/rtc-mc13xxx.c

+14 −18
Original line number Diff line number Diff line
@@ -64,12 +64,10 @@ static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) 
	unsigned long s1970;

	int ret;



	mc13xxx_lock(priv->mc13xxx);

	if (!priv->valid)

		return -ENODATA;



	if (!priv->valid) {

		ret = -ENODATA;

		goto out;

	}

	mc13xxx_lock(priv->mc13xxx);



	ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);

	if (unlikely(ret))
@@ -154,11 +152,14 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs) 
			goto out;

	}



	if (!priv->valid) {

		ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);

		if (unlikely(ret))

			goto out;



		ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);

	}



out:

	priv->valid = !ret;
@@ -295,7 +296,7 @@ static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev) 
	struct mc13xxx_rtc *priv = dev;

	struct mc13xxx *mc13xxx = priv->mc13xxx;



	dev_dbg(&priv->rtc->dev, "RTCRST\n");

	dev_warn(&priv->rtc->dev, "Contents of the RTC are no longer valid\n");

	priv->valid = 0;



	mc13xxx_irq_mask(mc13xxx, irq);
@@ -308,7 +309,6 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev) 
	int ret;

	struct mc13xxx_rtc *priv;

	struct mc13xxx *mc13xxx;

	int rtcrst_pending;



	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)
@@ -316,6 +316,7 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev) 


	mc13xxx = dev_get_drvdata(pdev->dev.parent);

	priv->mc13xxx = mc13xxx;

	priv->valid = 1;



	platform_set_drvdata(pdev, priv);
@@ -326,18 +327,13 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev) 


	mc13xxx_lock(mc13xxx);



	mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);



	ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,

			mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);

	if (ret)

		goto err_reset_irq_request;



	ret = mc13xxx_irq_status(mc13xxx, MC13XXX_IRQ_RTCRST,

			NULL, &rtcrst_pending);

	if (ret)

		goto err_reset_irq_status;



	priv->valid = !rtcrst_pending;



	ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_1HZ,

			mc13xxx_rtc_update_handler, DRIVER_NAME, priv);

	if (ret)

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