[RFC 00/14] Add DT support to OMAPDSS

[Benoit Cousson]

Hi Tomi,

On 03/27/2013 09:45 AM, Tomi Valkeinen wrote:
> Hi,
> 
> This is an RFC for OMAPDSS DT support. I've only added support for a few boards
> and a few DSS outputs, but they should give quite a good range of different use
> cases. If these work well, I think the rest of the outputs and panels will be
> ok too.
> 
> The purpose of this series is to get comments about the dts changes. There are
> still work to be done, like adding DT binding documentation.
> 
> Some notes:
> 
> * DSS Submodules
> 
> The DSS submodules are children of the dss_core node. This is done because the
> submodules require the dss_core to be alive and initialized to work, even if
> the submodules are not really behind dss_core. Having the submodules as
> children will make runtime PM automatically handle the dependency to dss_core.
> I think usually a node being a child means that it's on the parent's bus, which
> is not the case here. I'm not sure if that's an issue or not.

FWIW, there is a L4_DSS interconnect. It is used internally to connect
all the submodules to the DSS L3 port. So this representation is
perfectly valid and does represent accurately the HW.

Regards,
Benoit

> 
> * ti,dsi-module-id
> 
> There's a ti,dsi-module-id property in the dsi node. The reason for this
> module-id property is that we have muxes in the dss_core that route clocks
> to/from a particular DSI module. So we need some way to index the DSI modules.
> Another option would be to have a list of DSI modules (phandles) in the
> dss_core. Both options feel a bit wrong to me, but I went for the module-id
> approach as that is already used when not using DT.
> 
> * Display chains
> 
> Currently omapdss driver can handle only one display device connected to one
> OMAP SoC output. This is not right in many cases, as there may be multiple
> display devices in a chain, like first an external encoder and then a panel.
> However, I tried to model this right in the dts. 
> 
> So, for example, for Panda HDMI output we have the following display "entities"
> in a chain: OMAP SoC HDMI output, TPD12S015 ESD/level shifter, and HDMI
> connector. These are connected using the "video-source" property, which tells
> where the component in question gets its video data.
> 
> You could ask why there's a separate node for HDMI connector. It's true it's
> not really a proper device, but we need some kind of terminator for the display
> chains. For HDMI we could as well have an embedded solution, having a chain
> like this: SoC HDMI, TPD12S015, hardwired embedded HDMI panel. So the connector
> marks the end of the chain, and acts as a panel in a sense.
> 
> * DSI lanes
> 
> The DSI panels contain "lanes" property, which tells how the SoCs DSI pins are
> connected to the DSI panel. I'm not sure if the panel data is the proper place
> for this, or should the data be separately for the OMAP DSI node.
> 
>  Tomi
> 
> Tomi Valkeinen (14):
>   ARM: OMAP: remove DSS DT hack
>   ARM: OMAP2+: add omapdss_init_of()
>   OMAPDSS: Add DT support to DSS, DISPC, DPI
>   OMAPDSS: Add DT support to DSI
>   OMAPDSS: Add DT support to HDMI
>   OMAPDSS: Taal: Add DT support
>   OMAPDSS: TFP410: Add DT support
>   OMAPDSS: panel-generic-dpi: add DT support
>   ARM: omap3.dtsi: add omapdss information
>   ARM: omap4.dtsi: add omapdss information
>   ARM: omap4-panda.dts: add display information
>   ARM: omap4-sdp.dts: add display information
>   ARM: omap3-tobi.dts: add lcd (TEST)
>   ARM: omap3-beagle.dts: add TFP410
> 
>  arch/arm/boot/dts/omap3-beagle.dts               |   20 +++++
>  arch/arm/boot/dts/omap3-tobi.dts                 |   13 ++++
>  arch/arm/boot/dts/omap3.dtsi                     |   49 ++++++++++++
>  arch/arm/boot/dts/omap4-panda.dts                |   44 +++++++++++
>  arch/arm/boot/dts/omap4-sdp.dts                  |   64 ++++++++++++++++
>  arch/arm/boot/dts/omap4.dtsi                     |   71 +++++++++++++++++
>  arch/arm/mach-omap2/board-generic.c              |    9 +--
>  arch/arm/mach-omap2/common.h                     |    2 +
>  arch/arm/mach-omap2/display.c                    |   34 +++++++++
>  arch/arm/mach-omap2/dss-common.c                 |   24 ------
>  arch/arm/mach-omap2/dss-common.h                 |    2 -
>  drivers/video/omap2/displays/panel-generic-dpi.c |   47 ++++++++++++
>  drivers/video/omap2/displays/panel-taal.c        |   89 ++++++++++++++++++++++
>  drivers/video/omap2/displays/panel-tfp410.c      |   71 +++++++++++++++++
>  drivers/video/omap2/dss/dispc.c                  |    7 ++
>  drivers/video/omap2/dss/dpi.c                    |    8 ++
>  drivers/video/omap2/dss/dsi.c                    |   24 +++++-
>  drivers/video/omap2/dss/dss.c                    |    7 ++
>  drivers/video/omap2/dss/hdmi.c                   |    7 ++
>  drivers/video/omap2/dss/hdmi_panel.c             |   86 ++++++++++++++++++++-
>  20 files changed, 641 insertions(+), 37 deletions(-)
>