RTC Alarm interrupt and programming

Mike Sloman mikes at mikes.id.au
Wed May 23 02:30:04 EDT 2007

Hi all,

I am fleshing out an idea for a Calendar/Alarm activity "Calarm" and 
need to know if there is any current support for the RTC alarm mode.

The CS5536 Southbridge has a month/day/hh/MM/SS alarm built in and I 
assume that it is this that is used for timekeeping and not the EC? ie: 
does the EC have a RTC and can bring laptop out of shutdown? Or only 
suspend wakeup from southbridge?

* Is there support for waking CPU/system from suspend mode on Alarm Int?
* Userland access to set alarm time and enable?
* Interrupt service to signal activity (via DBUS?) of alarm going off?
* Activity level requests for suspend mode or just power button only?

General timekeeping Questions:

* RTC using UTC?
* I assume TZ offset and DLS settings from school server at first boot?

If there is a good reason why a Cal/alarm activity should not, or will 
not, be included on a OLPC please indicate this. Although it's not 
really an activity in the olpc sense it is still important for many people.

A brief summary of what I propose follows and if no-one has any 
objection then a full specification will be generated and remotely 
available for comment while I start coding base functionality.


* Internals all based on Gregorian RTC
* Graphical representation of calendar based on user selected setting 
ie: Gregorian, Islamic (Arabic,Urdu,Farsi), Jewish(Hebrew), Hindu,Thai, 
Australian Aboriginal etc etc.
* Localisation of standard Gregorian.
* At all times Gregorian equivalent date is presented in latin text as 
well as many places use both traditional and Greg.
* Events/ToDo/Appointments etc
* In day (or possible week view) access journal and show icons or list 
of things done that day.


* Repeating and single set alarms enabled by user for laptop wakeup
* Alarm when activated plays a sound and/or flashes the screen solid 
white. ie in mornings user specified wav/ogg file played and screen goes 
black to white to wake someone up. -- Relies on user suspending while in 
Calarm activity. (( Can a non-current activity make itself the current 
activity and/or control screen??))


* Events/Alarms etc internally stored in simple flat text or SQLite.
* Import and Export via iCal python library 
* User laptops get a iCal file from the schools server with school 
and/or local holidays, schools days/time, other important national dates 
etc when they backup to the server. == Requires XS support ==


1. Just Gregorian Calendar with localisation support first.
2. Add Alarm.
3. Add non Gregorian support with suitable localisations.
4. iCal import/export and internal appt/todo etc support.
5. Journal support.


Mike Sloman.

Mike Sloman

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