[U-Boot] [PATCH RESEND 7/9] video: Allow board hook before video init

[Maxime Ripard]

On Wed, Nov 23, 2016 at 07:21:07PM -0700, Simon Glass wrote:
> Hi Maxime,
> 
> On 22 November 2016 at 05:41, Maxime Ripard
> <maxime.ripard at free-electrons.com> wrote:
> > Hi Simon,
> >
> > On Mon, Nov 14, 2016 at 01:44:45PM -0700, Simon Glass wrote:
> >> Hi Maxime,
> >>
> >> On 14 November 2016 at 13:24, Maxime Ripard
> >> <maxime.ripard at free-electrons.com> wrote:
> >> > Hi Simon,
> >> >
> >> > On Fri, Nov 11, 2016 at 09:17:28AM -0700, Simon Glass wrote:
> >> >> Hi Maxime,
> >> >>
> >> >> On 8 November 2016 at 03:19, Maxime Ripard
> >> >> <maxime.ripard at free-electrons.com> wrote:
> >> >> > Some boards might need to some additional setup right before initialising
> >> >> > the video console.
> >> >> >
> >> >> > Add some hook to allow that.
> >> >>
> >> >> Instead of this, can you use driver model (UCLASS_VIDEO)?
> >> >
> >> > I don't really know the device model that well, hence 'm not really
> >> > sure how would that help. Can a board register a hook to be called
> >> > before a driver is probed?
> >>
> >> My suggest would be that the driver can do whatever is required. What
> >> is the board-specific code actually wanting to do?
> >
> > We need to adjust the video-mode environment variable that is going to
> > be used in the driver's initialisation. We're doing that by
> > identifying which daughter board is attached, and then setting that
> > value according to the display output we want to use.
> >
> > So we need some hook that would run between the environment
> > initialisation and the video driver's init.
> 
> As an example of how you might pass platform data to the video driver,
> see board_init() in gurnard.c.

That's very useful, thanks!

Can you also postpone the probe of one driver, or at least defer a
driver's probe until some other is done?

The way we identify the daughter boards also rely on some driver in
the device model (a 1-Wire EEPROM, connected on a GPIO, both of them
also being part of the device model), so we need to defer the video
driver probe until both of them have been probed and accessed.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20161206/16242271/attachment.sig>