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

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are no longer valid due to the reset, a timer reset interrupt function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
......@@ -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;
}
ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
if (unlikely(ret))
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);
}
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dev, "Contents of the RTC are no longer valid\n");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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