Handle the Oscillator Failure ('OF') bit from Oscillator Status register
(0x1D). This bit is cleared on set_time function and is read each time the
date/time is read, but only in case of XT Oscillator selection.
In RC mode, this bit is always set.
Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The autocalibration is separated in two bits to set in Oscillator
Control register (0x1c) :
- OSEL bit to select the oscillator type (XT or RC).
- ACAL bit to select the autocalibration type.
These functionnalities are exported in sysfs entries : "oscillator"
and "autocalibration". Respectively, the values are "xtal" for XT
oscillator and "rc" for RC oscillator and 0 to disable the
autocalibration cycle, 512 for a 512 seconds autocalibration cycle
and 1024 for a cycle of 1024 seconds.
Examples :
Set to XT Oscillator
echo xtal > /sys/class/rtc/rtc0/device/oscillator
Activate an autocalibration every 512 seconds
echo 512 > /sys/class/rtc/rtc0/device/autocalibration
Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This is a basic driver for the ultra-low-power Abracon AB x80x series of RTC
chips. It supports in particular, the supersets AB0805 and AB1805.
It allows reading and writing the time, and enables the supercapacitor/
battery charger.
[arnd@arndb.de: abx805 depends on i2c]
[alexandre.belloni@free-electrons.com: renam buffer from date to buf in abx80x_rtc_read_time()]
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mylène Josserand