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rtc: ds1347: handle century register

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The DS1347 can handle years from 0 to 9999, add century register support.

Link: https://lore.kernel.org/r/20191007134724.15505-10-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2019-10-07 15:47:24 +02:00
parent 860c45b56d
commit 147dae76db
1 changed files with 24 additions and 13 deletions
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37
drivers/rtc/rtc-ds1347.c
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@ -26,6 +26,7 @@
#define DS1347_DAY_REG 0x0B
#define DS1347_YEAR_REG 0x0D
#define DS1347_CONTROL_REG 0x0F
#define DS1347_CENTURY_REG 0x13
#define DS1347_STATUS_REG 0x17
#define DS1347_CLOCK_BURST 0x3F
@ -49,9 +50,9 @@ 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 int status, century, secs;
unsigned char buf[8];
int err;
err = regmap_read(map, DS1347_STATUS_REG, &status);
if (err)
@ -60,9 +61,19 @@ static int ds1347_read_time(struct device *dev, struct rtc_time *dt)
if (status & DS1347_OSF_BIT)
return -EINVAL;
err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);
if (err)
return err;
do {
err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);
if (err)
return err;
err = regmap_read(map, DS1347_CENTURY_REG, &century);
if (err)
return err;
err = regmap_read(map, DS1347_SECONDS_REG, &secs);
if (err)
return err;
} while (buf[0] != secs);
dt->tm_sec = bcd2bin(buf[0]);
dt->tm_min = bcd2bin(buf[1] & 0x7f);
@ -70,7 +81,7 @@ static int ds1347_read_time(struct device *dev, struct rtc_time *dt)
dt->tm_mday = bcd2bin(buf[3]);
dt->tm_mon = bcd2bin(buf[4]) - 1;
dt->tm_wday = bcd2bin(buf[5]) - 1;
dt->tm_year = bcd2bin(buf[6]) + 100;
dt->tm_year = (bcd2bin(century) * 100) + bcd2bin(buf[6]) - 1900;
return 0;
}
@ -78,6 +89,7 @@ static int ds1347_read_time(struct device *dev, struct rtc_time *dt)
static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
{
struct regmap *map = dev_get_drvdata(dev);
unsigned int century;
unsigned char buf[8];
int err;
@ -92,19 +104,18 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
buf[3] = bin2bcd(dt->tm_mday);
buf[4] = bin2bcd(dt->tm_mon + 1);
buf[5] = bin2bcd(dt->tm_wday + 1);
/* year in linux is from 1900 i.e in range of 100
in rtc it is from 00 to 99 */
dt->tm_year = dt->tm_year % 100;
buf[6] = bin2bcd(dt->tm_year);
buf[6] = bin2bcd(dt->tm_year % 100);
buf[7] = bin2bcd(0x00);
/* write the rtc settings */
err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);
if (err)
return err;
century = (dt->tm_year / 100) + 19;
err = regmap_write(map, DS1347_CENTURY_REG, century);
if (err)
return err;
return regmap_update_bits(map, DS1347_STATUS_REG,
DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0);
}