From 147dae76dbb9b20ba48385911c6fc04bf038a64a Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Mon, 7 Oct 2019 15:47:24 +0200 Subject: [PATCH] rtc: ds1347: handle century register 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 --- drivers/rtc/rtc-ds1347.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c index a49ce9991916..7025cf3fb9f8 100644 --- a/drivers/rtc/rtc-ds1347.c +++ b/drivers/rtc/rtc-ds1347.c @@ -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, ¢ury); + 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); }