Commit 38ab97ae authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

rtc: ab8500: let the core handle range 



Let the core handle offsetting and windowing the RTC range.
The RTC has a 24 bit counter for minutes plus a seconds counter.
Keep the epoch at the beginning of 2000.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent b56295dd

drivers/rtc/rtc-ab8500.c

+4 −49
Original line number Diff line number Diff line
@@ -46,7 +46,6 @@ 
#define RTC_STATUS_DATA			0x01



#define COUNTS_PER_SEC			(0xF000 / 60)

#define AB8500_RTC_EPOCH		2000



static const u8 ab8500_rtc_time_regs[] = {

	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
@@ -59,23 +58,6 @@ static const u8 ab8500_rtc_alarm_regs[] = { 
	AB8500_RTC_ALRM_MIN_LOW_REG

};



/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */

static unsigned long get_elapsed_seconds(int year)

{

	unsigned long secs;

	struct rtc_time tm = {

		.tm_year = year - 1900,

		.tm_mday = 1,

	};



	/*

	 * This function calculates secs from 1970 and not from

	 * 1900, even if we supply the offset from year 1900.

	 */

	rtc_tm_to_time(&tm, &secs);

	return secs;

}



static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	unsigned long timeout = jiffies + HZ;
@@ -118,9 +100,6 @@ static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm) 
	secs =	secs / COUNTS_PER_SEC;

	secs =	secs + (mins * 60);



	/* Add back the initially subtracted number of seconds */

	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);



	rtc_time_to_tm(secs, tm);

	return 0;

}
@@ -131,21 +110,8 @@ static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm) 
	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];

	unsigned long no_secs, no_mins, secs = 0;



	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {

		dev_dbg(dev, "year should be equal to or greater than %d\n",

				AB8500_RTC_EPOCH);

		return -EINVAL;

	}



	/* Get the number of seconds since 1970 */

	rtc_tm_to_time(tm, &secs);



	/*

	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since

	 * we only have a small counter in the RTC.

	 */

	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);



	no_mins = secs / 60;



	no_secs = secs % 60;
@@ -202,9 +168,6 @@ static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);

	secs = mins * 60;



	/* Add back the initially subtracted number of seconds */

	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);



	rtc_time_to_tm(secs, &alarm->time);



	return rtc_valid_tm(&alarm->time);
@@ -224,12 +187,6 @@ static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
	unsigned long mins, secs = 0, cursec = 0;

	struct rtc_time curtm;



	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {

		dev_dbg(dev, "year should be equal to or greater than %d\n",

				AB8500_RTC_EPOCH);

		return -EINVAL;

	}



	/* Get the number of seconds since 1970 */

	rtc_tm_to_time(&alarm->time, &secs);
@@ -245,12 +202,6 @@ static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
		return -EINVAL;

	}



	/*

	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since

	 * we only have a small counter in the RTC.

	 */

	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);



	mins = secs / 60;



	buf[2] = mins & 0xFF;
@@ -445,6 +396,10 @@ static int ab8500_rtc_probe(struct platform_device *pdev) 


	rtc->uie_unsupported = 1;



	rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs

	rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;

	rtc->set_start_time = true;



	err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);

	if (err)

		return err;

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