[PREVIEW 2] New display subsystem for OMAP2/3

[PREVIEW 2] New display subsystem for OMAP2/3

[Tomi Valkeinen]

Hi,

I sent a preview of a new display subsystem for OMAP2/3 some time ago:
http://marc.info/?l=linux-omap&m=122114505030542&w=2

I now have updated it, the patches are at the same place:
http://www.bat.org/~tomba/omap-dss/

What's new
----------

As was pointed out in the feedback, my version was not enough to fully
utilize OMAP's DISPC. I did a bit of a rewrite and I now model the
overlays and overlay managers. This conveniently allows multiple display
configurations, and it also solved some other problems I had previously.
The code is still bit of a mess after this change.

The tv-out and DVI are also now working on OMAP3 SDP board, and you can
switch between, and combine, LCD, TV-out and DVI outputs. The current
interface for this is a couple of hackish sysfs files.

The Kconfig is also a bit more versatile, you can leave out the parts of
the DSS that you don't need.

Overlays
--------

Here's the default setup on OMAP3 SDP board. All planes go to LCD. DVI
and TV-out are not in use. The columns from left to right are:
framebuffers, overlays, overlay managers, displays. Framebuffers are
handled by omapfb, and the rest by the DSS.

FB0 --- GFX  -\            DVI
FB1 --- VID1 --+- LCD ---- LCD
FB2 --- VID2 -/   TV ----- TV

In the examples below we use DVI and TV so that the setup changes to the
following:

FB0 --- GFX  -\         -- DVI
FB1 --- VID1 --+- LCD -/   LCD
FB2 --- VID2 ---- TV ----- TV

It is also possible to setup a virtual overlay & overlay manager, which
can be used with displays that can be updated with CPU/sDMA. For
example:

FB3 --- VOVL ---- VMGR

You can also change the overlay to which a framebuffer is connected.
With this we can, for example, change fb0 from DISPC overlay to virtual
overlay while X is running on the framebuffer. This way X doesn't notice
anything, but DISPC is free for other displays.

And, although not implemented yet, one framebuffer can be connected to
multiple overlays. This will allow cloning of a framebuffer to multiple
outputs.

Sysfs
-----
The sysfs interface is a hack, but works for testing. And I don't think
sysfs interface is the best for this in the final version.

In /sys/devices/platform/omapfb we have four files: framebuffers,
overlays, managers and displays. You can read them so see the current
setup, and change it by writing "arg1:arg2" to it. So changing
framebuffer 0 to point to vid1 overlay would require writing "0:vid1" to
framebuffers file.

Examples
--------
In these examples I have symlink omapfb -> /sys/devices/platform/omapfb

# VIDEO2 plane to TV out
echo "vid2:" > omapfb/overlays                                 # (1)
fbset -fb /dev/fb2 -xres 720 -pw 720 -yres 482 -ph 482 -pe 1   # (2)
echo "vid2:tv" > omapfb/overlays                               # (3)
echo "tv:1" > omapfb/displays                                  # (4)

1. Detach vid2 overlay. Otherwise the DSS will reject the fbset, as
   the asked resolution is larger than the LCD's resolution.
2. Set x/y res, and enable plane
3. Attach vid2 to tv overlay manager.
4. Enable tv display

# Use DVI instead of LCD
echo "lcd:0" > omapfb/displays                                 # (1)
echo "lcd:" > omapfb/managers                                  # (2)
# switch the dvi/lcd dip-switch                                # (3)
fbset -fb /dev/fb0 -xres 800 -pw 800 -yres 600 -ph 600 -pe 1   # (4)
echo "lcd:dvi" > omapfb/managers                               # (5)
echo "dvi:1" > omapfb/displays                                 # (6)

1. Disable LCD display. We have to disable LCD before we can enable DVI
2. Detach LCD overlay manager
3. Here you have to set the DIP switch to DVI position
4. Set the new resolution
5. Attach LCD overlay manager to DVI display
6. Enable DVI display

 Tomi

Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Tony Lindgren]

Hi,

* Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
> Hi,
> 
> I sent a preview of a new display subsystem for OMAP2/3 some time ago:
> http://marc.info/?l=linux-omap&m=122114505030542&w=2
> 
> I now have updated it, the patches are at the same place:
> http://www.bat.org/~tomba/omap-dss/

This discussion should go to linux-fbdev-devel list. Please keep l-o
list Cc'd though. Also you should post the patches as a proper inline
series, please see git-send-email man page.

Tony

> 
> What's new
> ----------
> 
> As was pointed out in the feedback, my version was not enough to fully
> utilize OMAP's DISPC. I did a bit of a rewrite and I now model the
> overlays and overlay managers. This conveniently allows multiple display
> configurations, and it also solved some other problems I had previously.
> The code is still bit of a mess after this change.
> 
> The tv-out and DVI are also now working on OMAP3 SDP board, and you can
> switch between, and combine, LCD, TV-out and DVI outputs. The current
> interface for this is a couple of hackish sysfs files.
> 
> The Kconfig is also a bit more versatile, you can leave out the parts of
> the DSS that you don't need.
> 
> Overlays
> --------
> 
> Here's the default setup on OMAP3 SDP board. All planes go to LCD. DVI
> and TV-out are not in use. The columns from left to right are:
> framebuffers, overlays, overlay managers, displays. Framebuffers are
> handled by omapfb, and the rest by the DSS.
> 
> FB0 --- GFX  -\            DVI
> FB1 --- VID1 --+- LCD ---- LCD
> FB2 --- VID2 -/   TV ----- TV
> 
> In the examples below we use DVI and TV so that the setup changes to the
> following:
> 
> FB0 --- GFX  -\         -- DVI
> FB1 --- VID1 --+- LCD -/   LCD
> FB2 --- VID2 ---- TV ----- TV
> 
> It is also possible to setup a virtual overlay & overlay manager, which
> can be used with displays that can be updated with CPU/sDMA. For
> example:
> 
> FB3 --- VOVL ---- VMGR
> 
> You can also change the overlay to which a framebuffer is connected.
> With this we can, for example, change fb0 from DISPC overlay to virtual
> overlay while X is running on the framebuffer. This way X doesn't notice
> anything, but DISPC is free for other displays.
> 
> And, although not implemented yet, one framebuffer can be connected to
> multiple overlays. This will allow cloning of a framebuffer to multiple
> outputs.
> 
> Sysfs
> -----
> The sysfs interface is a hack, but works for testing. And I don't think
> sysfs interface is the best for this in the final version.
> 
> In /sys/devices/platform/omapfb we have four files: framebuffers,
> overlays, managers and displays. You can read them so see the current
> setup, and change it by writing "arg1:arg2" to it. So changing
> framebuffer 0 to point to vid1 overlay would require writing "0:vid1" to
> framebuffers file.
> 
> Examples
> --------
> In these examples I have symlink omapfb -> /sys/devices/platform/omapfb
> 
> # VIDEO2 plane to TV out
> echo "vid2:" > omapfb/overlays                                 # (1)
> fbset -fb /dev/fb2 -xres 720 -pw 720 -yres 482 -ph 482 -pe 1   # (2)
> echo "vid2:tv" > omapfb/overlays                               # (3)
> echo "tv:1" > omapfb/displays                                  # (4)
> 
> 1. Detach vid2 overlay. Otherwise the DSS will reject the fbset, as
>    the asked resolution is larger than the LCD's resolution.
> 2. Set x/y res, and enable plane
> 3. Attach vid2 to tv overlay manager.
> 4. Enable tv display
> 
> # Use DVI instead of LCD
> echo "lcd:0" > omapfb/displays                                 # (1)
> echo "lcd:" > omapfb/managers                                  # (2)
> # switch the dvi/lcd dip-switch                                # (3)
> fbset -fb /dev/fb0 -xres 800 -pw 800 -yres 600 -ph 600 -pe 1   # (4)
> echo "lcd:dvi" > omapfb/managers                               # (5)
> echo "dvi:1" > omapfb/displays                                 # (6)
> 
> 1. Disable LCD display. We have to disable LCD before we can enable DVI
> 2. Detach LCD overlay manager
> 3. Here you have to set the DIP switch to DVI position
> 4. Set the new resolution
> 5. Attach LCD overlay manager to DVI display
> 6. Enable DVI display
> 
>  Tomi
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Tomi Valkeinen]

Hi,

On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
> Hi,
> 
> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
> > Hi,
> > 
> > I sent a preview of a new display subsystem for OMAP2/3 some time ago:
> > http://marc.info/?l=linux-omap&m=122114505030542&w=2
> > 
> > I now have updated it, the patches are at the same place:
> > http://www.bat.org/~tomba/omap-dss/
> 
> This discussion should go to linux-fbdev-devel list. Please keep l-o
> list Cc'd though. Also you should post the patches as a proper inline
> series, please see git-send-email man page.
> 

Ok, I'll move it to linux-fbdev-devel.

I didn't post the patches inline, as they are quite big (250k+). I
thought there was a "rule" to put big patches to some public place, not
to mail them.

What is the proper procedure for this work? Discuss and review the
patches on fbdevel, and mail to l-o when finalized? Or go directly to
Linus' tree?

 Tomi

Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Koen Kooi]

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Op 23 sep 2008, om 10:19 heeft Tomi Valkeinen het volgende geschreven:

> Hi,
>
> On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
>> Hi,
>>
>> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
>>> Hi,
>>>
>>> I sent a preview of a new display subsystem for OMAP2/3 some time  
>>> ago:
>>> http://marc.info/?l=linux-omap&m=122114505030542&w=2
>>>
>>> I now have updated it, the patches are at the same place:
>>> http://www.bat.org/~tomba/omap-dss/
>>
>> This discussion should go to linux-fbdev-devel list. Please keep l-o
>> list Cc'd though. Also you should post the patches as a proper inline
>> series, please see git-send-email man page.
>>
>
> Ok, I'll move it to linux-fbdev-devel.
>
> I didn't post the patches inline, as they are quite big (250k+). I
> thought there was a "rule" to put big patches to some public place,  
> not
> to mail them.
>
> What is the proper procedure for this work? Discuss and review the
> patches on fbdevel, and mail to l-o when finalized? Or go directly to
> Linus' tree?

Or a branch on l-o (like pm-0)  that will get rebased when things  
change.

regards,

Koen


>
>
> Tomi
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux- 
> omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>


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Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Tony Lindgren]

* Koen Kooi <k.kooi@student.utwente.nl> [080923 11:41]:
>
> Op 23 sep 2008, om 10:19 heeft Tomi Valkeinen het volgende geschreven:
>
>> Hi,
>>
>> On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
>>> Hi,
>>>
>>> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
>>>> Hi,
>>>>
>>>> I sent a preview of a new display subsystem for OMAP2/3 some time  
>>>> ago:
>>>> http://marc.info/?l=linux-omap&m=122114505030542&w=2
>>>>
>>>> I now have updated it, the patches are at the same place:
>>>> http://www.bat.org/~tomba/omap-dss/
>>>
>>> This discussion should go to linux-fbdev-devel list. Please keep l-o
>>> list Cc'd though. Also you should post the patches as a proper inline
>>> series, please see git-send-email man page.
>>>
>>
>> Ok, I'll move it to linux-fbdev-devel.
>>
>> I didn't post the patches inline, as they are quite big (250k+). I
>> thought there was a "rule" to put big patches to some public place,  
>> not
>> to mail them.
>>
>> What is the proper procedure for this work? Discuss and review the
>> patches on fbdevel, and mail to l-o when finalized? Or go directly to
>> Linus' tree?
>
> Or a branch on l-o (like pm-0)  that will get rebased when things  
> change.

I'd suggest discussing it on fbdevel list, and then have the necessary
patches included into the mainline kernel via fbdevel. If you cc l-o
list, people will have a chance to comment also.

Once you have an ack from the fbdevel list, we can apply the patches
for testing into l-o tree while waiting for the patches to come down
to l-o tree from the mainline tree.

And of course you might want to have your own branch for the patches
like Koen suggested. That will make it easy for people using l-o tree
to try them out by doing a pull from your branch.

Tony

Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Koen Kooi]

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Op 23 sep 2008, om 11:24 heeft Tony Lindgren het volgende geschreven:

> * Koen Kooi <k.kooi@student.utwente.nl> [080923 11:41]:
>>
>> Op 23 sep 2008, om 10:19 heeft Tomi Valkeinen het volgende  
>> geschreven:
>>> On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
>>>> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:

>>>> I sent a preview of a new display subsystem for OMAP2/3 some time
>>>>> ago:
>>>>> http://marc.info/?l=linux-omap&m=122114505030542&w=2
>>>>>
>>>>> I now have updated it, the patches are at the same place:
>>>>> http://www.bat.org/~tomba/omap-dss/
>>>>
>>>> This discussion should go to linux-fbdev-devel list. Please keep  
>>>> l-o
>>>> list Cc'd though. Also you should post the patches as a proper  
>>>> inline
>>>> series, please see git-send-email man page.
>>>>
>>>
>>> Ok, I'll move it to linux-fbdev-devel.
>>>
>>> I didn't post the patches inline, as they are quite big (250k+). I
>>> thought there was a "rule" to put big patches to some public place,
>>> not
>>> to mail them.
>>>
>>> What is the proper procedure for this work? Discuss and review the
>>> patches on fbdevel, and mail to l-o when finalized? Or go directly  
>>> to
>>> Linus' tree?
>>
>> Or a branch on l-o (like pm-0)  that will get rebased when things
>> change.
>
> I'd suggest discussing it on fbdevel list, and then have the necessary
> patches included into the mainline kernel via fbdevel. If you cc l-o
> list, people will have a chance to comment also.

This patch also hooks into boardcode for omap3 boards, which AFAIK  
aren't in mainline yet, which makes it hard to funnel a working patch  
through the fbdev tree to mainline. But apart from that, going through  
fbdev-devel first would cut down on tedious review rounds later on.
Does davinci share enough bits to make this DSS lib work for that as  
well?

regards,

Koen

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Re: [PREVIEW 2] New display subsystem for OMAP2/3

[Tony Lindgren]

* Koen Kooi <k.kooi@student.utwente.nl> [080923 13:27]:
>
> Op 23 sep 2008, om 11:24 heeft Tony Lindgren het volgende geschreven:
>
>> * Koen Kooi <k.kooi@student.utwente.nl> [080923 11:41]:
>>>
>>> Op 23 sep 2008, om 10:19 heeft Tomi Valkeinen het volgende  
>>> geschreven:
>>>> On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
>>>>> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
>
>>>>> I sent a preview of a new display subsystem for OMAP2/3 some time
>>>>>> ago:
>>>>>> http://marc.info/?l=linux-omap&m=122114505030542&w=2
>>>>>>
>>>>>> I now have updated it, the patches are at the same place:
>>>>>> http://www.bat.org/~tomba/omap-dss/
>>>>>
>>>>> This discussion should go to linux-fbdev-devel list. Please keep  
>>>>> l-o
>>>>> list Cc'd though. Also you should post the patches as a proper  
>>>>> inline
>>>>> series, please see git-send-email man page.
>>>>>
>>>>
>>>> Ok, I'll move it to linux-fbdev-devel.
>>>>
>>>> I didn't post the patches inline, as they are quite big (250k+). I
>>>> thought there was a "rule" to put big patches to some public place,
>>>> not
>>>> to mail them.
>>>>
>>>> What is the proper procedure for this work? Discuss and review the
>>>> patches on fbdevel, and mail to l-o when finalized? Or go directly  
>>>> to
>>>> Linus' tree?
>>>
>>> Or a branch on l-o (like pm-0)  that will get rebased when things
>>> change.
>>
>> I'd suggest discussing it on fbdevel list, and then have the necessary
>> patches included into the mainline kernel via fbdevel. If you cc l-o
>> list, people will have a chance to comment also.
>
> This patch also hooks into boardcode for omap3 boards, which AFAIK  
> aren't in mainline yet, which makes it hard to funnel a working patch  
> through the fbdev tree to mainline. But apart from that, going through  
> fbdev-devel first would cut down on tedious review rounds later on.
> Does davinci share enough bits to make this DSS lib work for that as  
> well?

The drivers should be independent of the platform_data in the
board-*.c files as it may take a while longer to get the omap3
board-*.c files into the mainline kernel.

Tony

RE: [PREVIEW 2] New display subsystem for OMAP2/3

[Hiremath, Vaibhav]

Thanks,
Vaibhav Hiremath
Senior Software Engg.
Platform Support Products
Texas Instruments Inc
Ph: +91-80-25099927

> -----Original Message-----
> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Tony
> Lindgren
> Sent: Tuesday, September 23, 2008 4:11 PM
> To: Koen Kooi
> Cc: linux-omap@vger.kernel.org List
> Subject: Re: [PREVIEW 2] New display subsystem for OMAP2/3
> 
> * Koen Kooi <k.kooi@student.utwente.nl> [080923 13:27]:
> >
> > Op 23 sep 2008, om 11:24 heeft Tony Lindgren het volgende geschreven:
> >
> >> * Koen Kooi <k.kooi@student.utwente.nl> [080923 11:41]:
> >>>
> >>> Op 23 sep 2008, om 10:19 heeft Tomi Valkeinen het volgende
> >>> geschreven:
> >>>> On Mon, 2008-09-22 at 18:10 +0300, ext Tony Lindgren wrote:
> >>>>> * Tomi Valkeinen <tomi.valkeinen@nokia.com> [080922 17:49]:
> >
> >>>>> I sent a preview of a new display subsystem for OMAP2/3 some time
> >>>>>> ago:
> >>>>>> http://marc.info/?l=linux-omap&m=122114505030542&w=2
> >>>>>>
> >>>>>> I now have updated it, the patches are at the same place:
> >>>>>> http://www.bat.org/~tomba/omap-dss/
> >>>>>
> >>>>> This discussion should go to linux-fbdev-devel list. Please keep
> >>>>> l-o
> >>>>> list Cc'd though. Also you should post the patches as a proper
> >>>>> inline
> >>>>> series, please see git-send-email man page.
> >>>>>
> >>>>
> >>>> Ok, I'll move it to linux-fbdev-devel.
> >>>>
> >>>> I didn't post the patches inline, as they are quite big (250k+). I
> >>>> thought there was a "rule" to put big patches to some public place,
> >>>> not
> >>>> to mail them.
> >>>>
> >>>> What is the proper procedure for this work? Discuss and review the
> >>>> patches on fbdevel, and mail to l-o when finalized? Or go directly
> >>>> to
> >>>> Linus' tree?
> >>>
> >>> Or a branch on l-o (like pm-0)  that will get rebased when things
> >>> change.
> >>
> >> I'd suggest discussing it on fbdevel list, and then have the necessary
> >> patches included into the mainline kernel via fbdevel. If you cc l-o
> >> list, people will have a chance to comment also.
> >
> > This patch also hooks into boardcode for omap3 boards, which AFAIK
> > aren't in mainline yet, which makes it hard to funnel a working patch
> > through the fbdev tree to mainline. But apart from that, going through
> > fbdev-devel first would cut down on tedious review rounds later on.
> > Does davinci share enough bits to make this DSS lib work for that as
> > well?
> 

I believe that this discussion is happening for separate FBDEV driver which will be
compliant to DSS library posted few days back (http://lists-archives.org/video4linux/24409-omap2-3-dss-library.html).


> The drivers should be independent of the platform_data in the
> board-*.c files as it may take a while longer to get the omap3
> board-*.c files into the mainline kernel.
> 
> Tony
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
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