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authorStephen Warren <swarren@nvidia.com>2014-01-23 15:55:19 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-06 11:08:15 -0800
commit0ac9f15fbe599024fa3523c3083add257f53c849 (patch)
treea028d0f5d6a3959af2659a41c8f6fbcf48ae3ddc /drivers/rtc
parentd35b93d05eb82babe49fd76a68b94d803f2ed19a (diff)
rtc: max8907: weekday encoding fixes
commit 75ea799df4cb07e505c91b4abaa87bc28aad3e66 upstream. The current MAX8907 driver has two issues related to weekday value handling: 1) The HW WEEKDAY register has range 0..6 rather than 1..7 as documented. Note that I validated the actual HW range by observing the HW register roll from 6->0 rather than 6->7->1 as would otherwise be expected. This matches Linux's tm_wday range of 0..6. When the CMOS RAM content is lost, the date returned from the device is 2007-01-01 00:00:00, which is a Monday. The WEEKDAY register reads 1 in this case. This matches the numbering in Linux's tm_wday field. Hence we should write Linux's tm_wday value to the register without modifying it. Hence, remove the +1/-1 calculations for WEEKDAY/tm_wday. 2) There's no need to make alarms match on the WEEKDAY register, since the other fields together uniquely define the alarm date/time. Ignoring the WEEKDAY value in the match isolates the driver from any incorrect value in the current time copy of the WEEKDAY register. Each change individually, or both together, solves an issue that I observed; "hwclock -r" would time out waiting for its alarm to fire if the CMOS RAM content had been lost, and hence the WEEKDAY register value mismatched what the driver expected it to be. "hwclock -w" would solve this by over-writing the HW default WEEKDAY register value with what the driver expected. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-max8907.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/rtc/rtc-max8907.c b/drivers/rtc/rtc-max8907.c
index 86afb797125d..5d0ce597ba83 100644
--- a/drivers/rtc/rtc-max8907.c
+++ b/drivers/rtc/rtc-max8907.c
@@ -51,7 +51,7 @@ static irqreturn_t max8907_irq_handler(int irq, void *data)
{
struct max8907_rtc *rtc = data;
- regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);
+ regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
@@ -64,7 +64,7 @@ static void regs_to_tm(u8 *regs, struct rtc_time *tm)
bcd2bin(regs[RTC_YEAR1]) - 1900;
tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
- tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07) - 1;
+ tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07);
if (regs[RTC_HOUR] & HOUR_12) {
tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
if (tm->tm_hour == 12)
@@ -88,7 +88,7 @@ static void tm_to_regs(struct rtc_time *tm, u8 *regs)
regs[RTC_YEAR1] = bin2bcd(low);
regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
regs[RTC_DATE] = bin2bcd(tm->tm_mday);
- regs[RTC_WEEKDAY] = tm->tm_wday + 1;
+ regs[RTC_WEEKDAY] = tm->tm_wday;
regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
regs[RTC_MIN] = bin2bcd(tm->tm_min);
regs[RTC_SEC] = bin2bcd(tm->tm_sec);
@@ -153,7 +153,7 @@ static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
tm_to_regs(&alrm->time, regs);
/* Disable alarm while we update the target time */
- ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);
+ ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
if (ret < 0)
return ret;
@@ -163,8 +163,7 @@ static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
return ret;
if (alrm->enabled)
- ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL,
- 0x7f, 0x7f);
+ ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77);
return ret;
}