[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Igor Opaniuk]

Marek, Peng,

Writing to you as you were the main contributors to U-boot mxsfb
driver implementation (i.MX23/i.MX28 LCDIF driver).

I was about to start working on it's migration to DM (currently mxsfb
is being used on our SoM Colibri iMX7S/D), but found it a bit
out-dated (no one introduced any changes for the last 5 years) and
maybe it's really does make a sense to fetch and port the latest one
from the Linux mainline (in a sake of avoiding divergence in
implementation and continue fetching future updates from the Linux
kernel).

So there are 2 questions spinning in my mind:
1) In case if you are maybe aware, if there were any intentions to do
this migration before?  (maybe someone asked similar questions or even
send some patches, but didn't manage to upstream that; or did similar
stuff in some downstream U-boot forks, whatever). Unfortunately I
can't any information regarding this in U-boot ML archives .

2) Will it be OK if I introduce a brand new mxsfb driver (ported from
Linux), which will be used only when U-boot is built with
CONFIG_DM_VIDEO enabled? Existing mxsfb will be left as it is, so I
can be removed easily when full migration to DM is done for all boards
that are using this driver.

Simon,

Could you also provide you feedback for 2 (if introducing a brand new
dm-enabled driver is a good idea), thanks!

Thanks in advance for you comments/suggestions!

-- 
Best regards - Freundliche Grüsse - Meilleures salutations

Senior Development Engineer,
Igor Opaniuk

Toradex AG
Altsagenstrasse 5 | 6048 Horw/Luzern | Switzerland | T: +41 41 500 48
00 (main line)

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Anatolij Gustschin]

Hi Igor,

On Tue, 16 Apr 2019 12:04:41 +0000
Igor Opaniuk igor.opaniuk at toradex.com wrote:
...
> So there are 2 questions spinning in my mind:
> 1) In case if you are maybe aware, if there were any intentions to do
> this migration before?  (maybe someone asked similar questions or even
> send some patches, but didn't manage to upstream that; or did similar
> stuff in some downstream U-boot forks, whatever). Unfortunately I
> can't any information regarding this in U-boot ML archives .

I'm not aware of any activity migrating this driver to DM_VIDEO.
Patches welcome.
 
> 2) Will it be OK if I introduce a brand new mxsfb driver (ported from
> Linux), which will be used only when U-boot is built with
> CONFIG_DM_VIDEO enabled? Existing mxsfb will be left as it is, so I
> can be removed easily when full migration to DM is done for all boards
> that are using this driver.

I have no objections. However I don't know how big is the Linux mxsfb
driver, maybe we could reduce not needed code to keep the code size
smaller.

--
Anatolij

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Igor Opaniuk]

Hi Anatolij,

Thanks for your feedback!

On Tue, Apr 16, 2019 at 2:31 PM Anatolij Gustschin <agust@denx.de> wrote:
>
> Hi Igor,
>
> On Tue, 16 Apr 2019 12:04:41 +0000
> Igor Opaniuk igor.opaniuk at toradex.com wrote:
> ...
> > So there are 2 questions spinning in my mind:
> > 1) In case if you are maybe aware, if there were any intentions to do
> > this migration before?  (maybe someone asked similar questions or even
> > send some patches, but didn't manage to upstream that; or did similar
> > stuff in some downstream U-boot forks, whatever). Unfortunately I
> > can't any information regarding this in U-boot ML archives .
>
> I'm not aware of any activity migrating this driver to DM_VIDEO.
> Patches welcome.
>
> > 2) Will it be OK if I introduce a brand new mxsfb driver (ported from
> > Linux), which will be used only when U-boot is built with
> > CONFIG_DM_VIDEO enabled? Existing mxsfb will be left as it is, so I
> > can be removed easily when full migration to DM is done for all boards
> > that are using this driver.
>
> I have no objections. However I don't know how big is the Linux mxsfb
> driver, maybe we could reduce not needed code to keep the code size
> smaller.
>
> --
> Anatolij
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://lists.denx.de/listinfo/u-boot

Thanks!

--
Best regards - Freundliche Grüsse - Meilleures salutations

Senior Development Engineer,
Igor Opaniuk

Toradex AG
Altsagenstrasse 5 | 6048 Horw/Luzern | Switzerland | T: +41 41 500 48
00 (main line)

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Jagan Teki]

On Tue, Apr 16, 2019 at 5:36 PM Igor Opaniuk <igor.opaniuk@toradex.com> wrote:
>
> Marek, Peng,
>
> Writing to you as you were the main contributors to U-boot mxsfb
> driver implementation (i.MX23/i.MX28 LCDIF driver).
>
> I was about to start working on it's migration to DM (currently mxsfb
> is being used on our SoM Colibri iMX7S/D), but found it a bit
> out-dated (no one introduced any changes for the last 5 years) and
> maybe it's really does make a sense to fetch and port the latest one
> from the Linux mainline (in a sake of avoiding divergence in
> implementation and continue fetching future updates from the Linux
> kernel).
>
> So there are 2 questions spinning in my mind:
> 1) In case if you are maybe aware, if there were any intentions to do
> this migration before?  (maybe someone asked similar questions or even
> send some patches, but didn't manage to upstream that; or did similar
> stuff in some downstream U-boot forks, whatever). Unfortunately I
> can't any information regarding this in U-boot ML archives .
>
> 2) Will it be OK if I introduce a brand new mxsfb driver (ported from
> Linux), which will be used only when U-boot is built with
> CONFIG_DM_VIDEO enabled? Existing mxsfb will be left as it is, so I
> can be removed easily when full migration to DM is done for all boards
> that are using this driver.

How about keeping common code aside and make the existing driver to
support dm and non-dm. We can take the required changes on top of dm
code if possible, this would be prominent transition instead of having
separate code base.

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Igor Opaniuk]

Hi Jagan,

On Tue, Apr 16, 2019 at 2:35 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> On Tue, Apr 16, 2019 at 5:36 PM Igor Opaniuk <igor.opaniuk@toradex.com> wrote:
> >
> > Marek, Peng,
> >
> > Writing to you as you were the main contributors to U-boot mxsfb
> > driver implementation (i.MX23/i.MX28 LCDIF driver).
> >
> > I was about to start working on it's migration to DM (currently mxsfb
> > is being used on our SoM Colibri iMX7S/D), but found it a bit
> > out-dated (no one introduced any changes for the last 5 years) and
> > maybe it's really does make a sense to fetch and port the latest one
> > from the Linux mainline (in a sake of avoiding divergence in
> > implementation and continue fetching future updates from the Linux
> > kernel).
> >
> > So there are 2 questions spinning in my mind:
> > 1) In case if you are maybe aware, if there were any intentions to do
> > this migration before?  (maybe someone asked similar questions or even
> > send some patches, but didn't manage to upstream that; or did similar
> > stuff in some downstream U-boot forks, whatever). Unfortunately I
> > can't any information regarding this in U-boot ML archives .
> >
> > 2) Will it be OK if I introduce a brand new mxsfb driver (ported from
> > Linux), which will be used only when U-boot is built with
> > CONFIG_DM_VIDEO enabled? Existing mxsfb will be left as it is, so I
> > can be removed easily when full migration to DM is done for all boards
> > that are using this driver.
>
> How about keeping common code aside and make the existing driver to
> support dm and non-dm. We can take the required changes on top of dm
> code if possible, this would be prominent transition instead of having
> separate code base.

Actually this is what I started doing in the very begging, but the
thing is that current mxsfb driver should be fully re-implemented to
make it possible.
Taking into account that there is already a pretty high divergence
between the one in U-boot and another in Linux, I think it's better to
sync with the existing mxsfb inthen  Linux kernel instead of spending
twice much effort on supporting two different implementations in the
future.

Anyway legacy stuff supposed to be removed ASAP (when migration is
finished), so I really would like to keep the old implementation
aside.


> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://lists.denx.de/listinfo/u-boot



-- 
Best regards - Freundliche Grüsse - Meilleures salutations

Senior Development Engineer,
Igor Opaniuk

Toradex AG
Altsagenstrasse 5 | 6048 Horw/Luzern | Switzerland | T: +41 41 500 48
00 (main line)

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Peng Fan]

HI Igor,

> 
> Marek, Peng,
> 
> Writing to you as you were the main contributors to U-boot mxsfb driver
> implementation (i.MX23/i.MX28 LCDIF driver).
> 
> I was about to start working on it's migration to DM (currently mxsfb is being
> used on our SoM Colibri iMX7S/D), but found it a bit out-dated (no one
> introduced any changes for the last 5 years) and maybe it's really does make a
> sense to fetch and port the latest one from the Linux mainline (in a sake of
> avoiding divergence in implementation and continue fetching future updates
> from the Linux kernel).
> 
> So there are 2 questions spinning in my mind:
> 1) In case if you are maybe aware, if there were any intentions to do this
> migration before?  (maybe someone asked similar questions or even send
> some patches, but didn't manage to upstream that; or did similar stuff in some
> downstream U-boot forks, whatever). Unfortunately I can't any information
> regarding this in U-boot ML archives .

I do not have plan to work on this recently.

> 
> 2) Will it be OK if I introduce a brand new mxsfb driver (ported from Linux),
> which will be used only when U-boot is built with CONFIG_DM_VIDEO
> enabled? Existing mxsfb will be left as it is, so I can be removed easily when
> full migration to DM is done for all boards that are using this driver.

You mean porting drivers/gpu/drm/mxsfb/ to U-Boot?

Regards,
Peng.

> 
> Simon,
> 
> Could you also provide you feedback for 2 (if introducing a brand new
> dm-enabled driver is a good idea), thanks!
> 
> Thanks in advance for you comments/suggestions!
> 
> --
> Best regards - Freundliche Grüsse - Meilleures salutations
> 
> Senior Development Engineer,
> Igor Opaniuk
> 
> Toradex AG
> Altsagenstrasse 5 | 6048 Horw/Luzern | Switzerland | T: +41 41 500 48
> 00 (main line)

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Simon Glass]

Hi,

On Tue, 16 Apr 2019 at 16:28, Peng Fan <peng.fan@nxp.com> wrote:

> HI Igor,
>
> >
> > Marek, Peng,
> >
> > Writing to you as you were the main contributors to U-boot mxsfb driver
> > implementation (i.MX23/i.MX28 LCDIF driver).
> >
> > I was about to start working on it's migration to DM (currently mxsfb is
> being
> > used on our SoM Colibri iMX7S/D), but found it a bit out-dated (no one
> > introduced any changes for the last 5 years) and maybe it's really does
> make a
> > sense to fetch and port the latest one from the Linux mainline (in a
> sake of
> > avoiding divergence in implementation and continue fetching future
> updates
> > from the Linux kernel).
> >
> > So there are 2 questions spinning in my mind:
> > 1) In case if you are maybe aware, if there were any intentions to do
> this
> > migration before?  (maybe someone asked similar questions or even send
> > some patches, but didn't manage to upstream that; or did similar stuff
> in some
> > downstream U-boot forks, whatever). Unfortunately I can't any information
> > regarding this in U-boot ML archives .
>
> I do not have plan to work on this recently.
>
> >
> > 2) Will it be OK if I introduce a brand new mxsfb driver (ported from
> Linux),
> > which will be used only when U-boot is built with CONFIG_DM_VIDEO
> > enabled? Existing mxsfb will be left as it is, so I can be removed
> easily when
> > full migration to DM is done for all boards that are using this driver.
>
> You mean porting drivers/gpu/drm/mxsfb/ to U-Boot?
>

DM_VIDEO will be compulsory soon anyway, so I think this is fine.

Regards,
Simon

[U-Boot] [RFC] Migrating iMX LCDIF drivers to Driver Model

[Fabio Estevam]

Hi Igor,

On Tue, Apr 16, 2019 at 8:28 PM Peng Fan <peng.fan@nxp.com> wrote:

> > 2) Will it be OK if I introduce a brand new mxsfb driver (ported from Linux),
> > which will be used only when U-boot is built with CONFIG_DM_VIDEO
> > enabled? Existing mxsfb will be left as it is, so I can be removed easily when
> > full migration to DM is done for all boards that are using this driver.

Sounds like a good plan.

Thanks