On Wed, 2011-04-20 at 11:13 +0530, Archit Taneja wrote:

On Tuesday 19 April 2011 02:52 PM, Valkeinen, Tomi wrote:

quoted

ULPS (Ultra-Low Power State) is a power saving method for DSI bus. When the
ULPS is entered, the host sends an ULPS entry sequence and pulls the DSI lines
down. On ULPS exit, the host sends an exit sequence and continues normal
operation. This allows both the host and the DSI peripheral to save some power
while in ULPS.

This patch set implements ULPS support for DSS2. ULPS can be used with DSI
command mode displays, and as command mode displays can refresh the panel
independently using its own framebuffer, entering ULPS allows OMAP DSS HW to be
totally turned off while the image on the display stays. This in turn may allow
OMAP to enter deep sleep.

Taal panel driver implements an inactivity timer which is used to enter ULPS
after a certain period. The period can configured via sysfs, "ulps_timeout"
file. A good value for the ulps_timeout depends on the use case and board, but
is most likely around 100-500ms.

The patch set does not enable the ULPS timeout, but it has to be enabled either
manually via sysfs or from the board file.

Tested on OMAP 4430 Blaze board. The patches are based on the current DSS2
master branch.

Tested on 4430sdp and 3430sdp with Taal Panel.

Thanks. I've applied the ULPS patch set to my master branch.

 Tomi