Commit c5776dec authored by Heinrich Schuchardt's avatar Heinrich Schuchardt Committed by Alexandre Belloni
Browse files

rtc: ds1685: correct day of month checking 



The day of month is checked in ds1685_rtc_read_alarm
and ds1685_rtc_set_alarm.

Multiple errors exist in the day of month check.

Operator ! has a higher priority than &&.
(!(mday >= 1) && (mday <= 31)) is false for mday == 32.

When verifying the day of month the binary and the BCD mode
have to be considered.

Signed-off-by: default avatarHeinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent 2b2f5ff0

drivers/rtc/rtc-ds1685.c

+29 −5
Original line number Diff line number Diff line
@@ -102,6 +102,26 @@ ds1685_rtc_bin2bcd(struct ds1685_priv *rtc, u8 val, u8 bin_mask, u8 bcd_mask) 
	return (val & bin_mask);

}



/**

 * s1685_rtc_check_mday - check validity of the day of month.

 * @rtc: pointer to the ds1685 rtc structure.

 * @mday: day of month.

 *

 * Returns -EDOM if the day of month is not within 1..31 range.

 */

static inline int

ds1685_rtc_check_mday(struct ds1685_priv *rtc, u8 mday)

{

	if (rtc->bcd_mode) {

		if (mday < 0x01 || mday > 0x31 || (mday & 0x0f) > 0x09)

			return -EDOM;

	} else {

		if (mday < 1 || mday > 31)

			return -EDOM;

	}

	return 0;

}



/**

 * ds1685_rtc_switch_to_bank0 - switch the rtc to bank 0.

 * @rtc: pointer to the ds1685 rtc structure.
@@ -377,6 +397,7 @@ ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	struct platform_device *pdev = to_platform_device(dev);

	struct ds1685_priv *rtc = platform_get_drvdata(pdev);

	u8 seconds, minutes, hours, mday, ctrlb, ctrlc;

	int ret;



	/* Fetch the alarm info from the RTC alarm registers. */

	ds1685_rtc_begin_data_access(rtc);
@@ -388,9 +409,10 @@ ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	ctrlc	= rtc->read(rtc, RTC_CTRL_C);

	ds1685_rtc_end_data_access(rtc);



	/* Check month date. */

	if (!(mday >= 1) && (mday <= 31))

		return -EDOM;

	/* Check the month date for validity. */

	ret = ds1685_rtc_check_mday(rtc, mday);

	if (ret)

		return ret;



	/*

	 * Check the three alarm bytes.
@@ -445,6 +467,7 @@ ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	struct platform_device *pdev = to_platform_device(dev);

	struct ds1685_priv *rtc = platform_get_drvdata(pdev);

	u8 ctrlb, seconds, minutes, hours, mday;

	int ret;



	/* Fetch the alarm info and convert to BCD. */

	seconds	= ds1685_rtc_bin2bcd(rtc, alrm->time.tm_sec,
@@ -461,8 +484,9 @@ ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
				     RTC_MDAY_BCD_MASK);



	/* Check the month date for validity. */

	if (!(mday >= 1) && (mday <= 31))

		return -EDOM;

	ret = ds1685_rtc_check_mday(rtc, mday);

	if (ret)

		return ret;



	/*

	 * Check the three alarm bytes.

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