rtc: rtc-ab-b5ze-s3: add sub-minute alarm support

Abracon AB-RTCMC-32.768kHz-B5ZE-S3 alarm is only accurate to the minute.
For that reason, UIE mode is currently not supported by the driver.  But
the device provides a watchdog timer which can be coupled with the alarm
mechanism to extend support and provide sub-minute alarm capability.

This patch implements that extension.  More precisely, it makes use of the
watchdog timer for alarms which are less that four minutes in the future
(with second accuracy) and use standard alarm mechanism for other alarms
(with minute accuracy).

Signed-off-by: Arnaud Ebalard <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Peter Huewe <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Pawel Moll <[email protected]>
Cc: Stephen Warren <[email protected]>
Cc: Ian Campbell <[email protected]>
Cc: Grant Likely <[email protected]>
Cc: Rob Landley <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kumar Gala <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions