From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: linux-rtc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Subject: [PATCH 08/10] rtc: ds1347: properly handle oscillator failures
Date: Mon, 7 Oct 2019 15:47:22 +0200 [thread overview]
Message-ID: <20191007134724.15505-8-alexandre.belloni@bootlin.com> (raw)
In-Reply-To: <20191007134724.15505-1-alexandre.belloni@bootlin.com>
The comment in the probe function stating that it disables oscillator stop
detection and glitch filtering is incorrect as it sets bits 3 and 4 while
it should be setting 5 and 6 to achieve that. Then, it is safe to assume
that the oscillator failure detection is actually enabled.
Properly handle oscillator failures by returning -EINVAL when the time and
date are know to be incorrect and reset the flag when the time is set.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
drivers/rtc/rtc-ds1347.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c
index 22a75b01f1ac..eeaf43586bce 100644
--- a/drivers/rtc/rtc-ds1347.c
+++ b/drivers/rtc/rtc-ds1347.c
@@ -29,6 +29,9 @@
#define DS1347_STATUS_REG 0x17
#define DS1347_CLOCK_BURST 0x3F
+#define DS1347_NEOSC_BIT BIT(7)
+#define DS1347_OSF_BIT BIT(2)
+
static const struct regmap_range ds1347_ranges[] = {
{
.range_min = DS1347_SECONDS_REG,
@@ -44,9 +47,17 @@ static const struct regmap_access_table ds1347_access_table = {
static int ds1347_read_time(struct device *dev, struct rtc_time *dt)
{
struct regmap *map = dev_get_drvdata(dev);
+ unsigned int status;
int err;
unsigned char buf[8];
+ err = regmap_read(map, DS1347_STATUS_REG, &status);
+ if (err)
+ return err;
+
+ if (status & DS1347_OSF_BIT)
+ return -EINVAL;
+
err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);
if (err)
return err;
@@ -66,6 +77,12 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
{
struct regmap *map = dev_get_drvdata(dev);
unsigned char buf[8];
+ int err;
+
+ err = regmap_update_bits(map, DS1347_STATUS_REG,
+ DS1347_NEOSC_BIT, DS1347_NEOSC_BIT);
+ if (err)
+ return err;
buf[0] = bin2bcd(dt->tm_sec);
buf[1] = bin2bcd(dt->tm_min);
@@ -82,7 +99,12 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
buf[7] = bin2bcd(0x00);
/* write the rtc settings */
- return regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);
+ err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);
+ if (err)
+ return err;
+
+ return regmap_update_bits(map, DS1347_STATUS_REG,
+ DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0);
}
static const struct rtc_class_ops ds1347_rtc_ops = {
@@ -123,12 +145,6 @@ static int ds1347_probe(struct spi_device *spi)
data = data & ~(1<<7);
regmap_write(map, DS1347_CONTROL_REG, data);
- /* Enable the oscillator , disable the oscillator stop flag,
- and glitch filter to reduce current consumption */
- regmap_read(map, DS1347_STATUS_REG, &data);
- data = data & 0x1B;
- regmap_write(map, DS1347_STATUS_REG, data);
-
rtc = devm_rtc_allocate_device(&spi->dev);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
--
2.21.0
next prev parent reply other threads:[~2019-10-07 13:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 13:47 [PATCH 01/10] rtc: add a timestamp for year 0 Alexandre Belloni
2019-10-07 13:47 ` [PATCH 02/10] rtc: ds1347: remove verbose messages Alexandre Belloni
2019-10-07 13:47 ` [PATCH 03/10] rtc: ds1347: remove useless read Alexandre Belloni
2019-10-07 13:47 ` [PATCH 04/10] rtc: ds1347: simplify getting .driver_data Alexandre Belloni
2019-10-07 13:47 ` [PATCH 05/10] rtc: ds1347: mask ALM OUT when reading time Alexandre Belloni
2019-10-07 13:47 ` [PATCH 06/10] rtc: ds1347: convert to devm_rtc_allocate_device Alexandre Belloni
2019-10-07 13:47 ` [PATCH 07/10] rtc: ds1347: set range Alexandre Belloni
2019-10-07 13:47 ` Alexandre Belloni [this message]
2019-10-07 13:47 ` [PATCH 09/10] rtc: ds1347: use regmap_update_bits Alexandre Belloni
2019-10-07 13:47 ` [PATCH 10/10] rtc: ds1347: handle century register Alexandre Belloni
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