The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Add support for reading and writing the RTC offset register, converting
it to the corresponding parts-per-billion value.
When setting the drift, the PCF8523 has two modes: one applies the
adjustment every two hours, the other applies the adjustment every
minute. We select between these two modes according to which ever
gives the closest PPB value to the one requested.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The time and date register of the pcf8223 are undefined after a power
reset. Properly handle the OS bit and return -EINVAL when that bit is set.
It is properly removed when setting the time.
This solves an issue where the time and date may be valid for
rtc_valid_tm() but is not the current time.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
When the chip increments the YEAR register and it already holds
bin2bcd(99) it reads as 0 afterwards. With this behaviour the last valid
day (without trickery) that has a representation is 2099-12-31 23:59:59.
So refuse to write later dates.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Implement reading of the battery voltage low signal for rtc-pcf8523.
The bit is read-only and cannot be cleared by software, so no
clear function is implemented.
[akpm@linux-foundation.org: omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n]
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
