Commit 147dae76 authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

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: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 860c45b5

drivers/rtc/rtc-ds1347.c

+24 −13
Original line number Original line Diff line number Diff line
@@ -26,6 +26,7 @@ 
#define DS1347_DAY_REG		0x0B

#define DS1347_DAY_REG		0x0B

#define DS1347_YEAR_REG		0x0D

#define DS1347_YEAR_REG		0x0D

#define DS1347_CONTROL_REG	0x0F

#define DS1347_CONTROL_REG	0x0F

#define DS1347_CENTURY_REG	0x13

#define DS1347_STATUS_REG	0x17

#define DS1347_STATUS_REG	0x17

#define DS1347_CLOCK_BURST	0x3F

#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)

static int ds1347_read_time(struct device *dev, struct rtc_time *dt)

{

{

	struct regmap *map = dev_get_drvdata(dev);

	struct regmap *map = dev_get_drvdata(dev);

	unsigned int status;

	unsigned int status, century, secs;

	int err;

	unsigned char buf[8];

	unsigned char buf[8];

	int err;





	err = regmap_read(map, DS1347_STATUS_REG, &status);

	err = regmap_read(map, DS1347_STATUS_REG, &status);

	if (err)

	if (err)
@@ -60,17 +61,27 @@ static int ds1347_read_time(struct device *dev, struct rtc_time *dt) 
	if (status & DS1347_OSF_BIT)

	if (status & DS1347_OSF_BIT)

		return -EINVAL;

		return -EINVAL;





	do {

		err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);

		err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);

		if (err)

		if (err)

			return 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_sec = bcd2bin(buf[0]);

	dt->tm_min = bcd2bin(buf[1] & 0x7f);

	dt->tm_min = bcd2bin(buf[1] & 0x7f);

	dt->tm_hour = bcd2bin(buf[2] & 0x3F);

	dt->tm_hour = bcd2bin(buf[2] & 0x3F);

	dt->tm_mday = bcd2bin(buf[3]);

	dt->tm_mday = bcd2bin(buf[3]);

	dt->tm_mon = bcd2bin(buf[4]) - 1;

	dt->tm_mon = bcd2bin(buf[4]) - 1;

	dt->tm_wday = bcd2bin(buf[5]) - 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;

	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)

static int ds1347_set_time(struct device *dev, struct rtc_time *dt)

{

{

	struct regmap *map = dev_get_drvdata(dev);

	struct regmap *map = dev_get_drvdata(dev);

	unsigned int century;

	unsigned char buf[8];

	unsigned char buf[8];

	int err;

	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[3] = bin2bcd(dt->tm_mday);

	buf[4] = bin2bcd(dt->tm_mon + 1);

	buf[4] = bin2bcd(dt->tm_mon + 1);

	buf[5] = bin2bcd(dt->tm_wday + 1);

	buf[5] = bin2bcd(dt->tm_wday + 1);



	buf[6] = bin2bcd(dt->tm_year % 100);

	/* 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[7] = bin2bcd(0x00);

	buf[7] = bin2bcd(0x00);





	/* write the rtc settings */

	err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);

	err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);

	if (err)

	if (err)

		return 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,

	return regmap_update_bits(map, DS1347_STATUS_REG,

				  DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0);

				  DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0);

}

}