There is a good, but short, article about the state of power management on the next generation Maemo devices at lwn.net (subscription required or free but you have to wait until Thursday).
In the article, Nokia’s Peter De Schrijver talks about the 4 modes of power management that will be available in the next platform, “on”, “inactive”, “retention” and “off”. These modes will govern how the device draws power and careful optimizations will ultimately dictate how long the battery life of these new devices will last.
Its good to see that careful attention is being shown to this often neglected area. For example, the very functional Android based G1 mobile phone is hampered by its ridiculously short battery life. It doesn’t matter that the phone has some killer apps, or that its running Linux under the hood, if the battery runs down in less than a day. Lets hope that Nokia can tame the OMAP 3 architecture into lasting at least as long as its predecessors.
It looks like this code for the power management optimizations will be ready soon, quoting the lwn.net article, Peter De Schrijver said,
The “retention” state works. Basic “off” mode works on most development boards; drivers are being adapted for “off” mode now and will be ready at the end of February.