Re: [PATCH 00/19] OMAP: DSS2: ULPS support

[Archit Taneja <archit@ti.com>]

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

Archit
>
>   Tomi
>
> Tomi Valkeinen (19):
>    OMAP: DSS2: DSI: Add lane override functions
>    OMAP: DSS2: DSI: Remove CIO LDO status check
>    OMAP: DSS2: DSI: implement ULPS enter and exit
>    OMAP: DSS2: DSI: add option to leave DSI lanes powered on
>    OMAP: DSS2: DSI: rename complexio related functions
>    OMAP: DSS2: Add FEAT_DSI_REVERSE_TXCLKESC
>    OMAP: DSS2: DSI: fix _dsi_print_reset_status
>    OMAP: DSS2: DSI: implement enable/disable SCP clk
>    OMAP: DSS2: DSI: fix CIO init and uninit
>    OMAP: DSS2: DSI: wait for TXCLKESC domain to come out of reset
>    OMAP: DSS2: DSI: add parameter to enter ulps on disable
>    OMAP: DSS2: DSI: Add DSI pad muxing support
>    OMAP: DSS2: DSI: ensure VDDS_DSI is disabled on exit
>    OMAP: DSS2: Taal: Implement configurable ESD interval
>    OMAP: DSS2: Taal: Clean up ESD queueing
>    OMAP: DSS2: Taal: Add sysfs file for ESD interval
>    OMAP: DSS2: Taal: Separate panel reset
>    OMAP: DSS2: Taal: Rename esd_wq to workqueue
>    OMAP: DSS2: Taal: Implement ULPS functionality
>
>   arch/arm/mach-omap2/board-4430sdp.c               |    2 +-
>   arch/arm/plat-omap/include/plat/display.h         |    4 +-
>   arch/arm/plat-omap/include/plat/nokia-dsi-panel.h |    6 +-
>   drivers/video/omap2/displays/panel-taal.c         |  420 +++++++++++++++++++--
>   drivers/video/omap2/dss/dpi.c                     |    4 +-
>   drivers/video/omap2/dss/dsi.c                     |  427 +++++++++++++++++----
>   drivers/video/omap2/dss/dss.h                     |    2 +-
>   drivers/video/omap2/dss/dss_features.c            |    4 +-
>   drivers/video/omap2/dss/dss_features.h            |    6 +-
>   9 files changed, 764 insertions(+), 111 deletions(-)
>
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