[U-Boot] [PATCH v2 11/19] tegra: Add LCD support to Nvidia boards

[Stephen Warren]

On 07/10/2012 10:58 PM, Simon Glass wrote:
> Hi Stephen,
> 
> On Fri, Jun 15, 2012 at 1:47 AM, Stephen Warren <swarren at wwwdotorg.org
> <mailto:swarren at wwwdotorg.org>> wrote:
> 
>     On 06/13/2012 10:19 AM, Simon Glass wrote:
>     > Add calls to the LCD driver from Nvidia board code.
> 
>     > diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
> 
>     > @@ -87,6 +88,9 @@ int board_init(void)
> 
>     > +#ifdef CONFIG_VIDEO_TEGRA2
>     > +     tegra_lcd_check_next_stage(gd->blob, 0);
>     > +#endif
> 
>     This seems to be conflating video support with LCD support. It would be
>     quite possible to have a board with no LCD, yet supporting display over
>     HDMI for example. In other words, shouldn't the ifdef above be something
>     more like:
> 
>     #if define(CONFIG_LCD_SUPPORT)
>             register_lcd_driver();
>     #endif
>     #if defined(CONFIG_VIDEO_TEGRA2)
>             tegra_display_init(...);
>     #endif
> 
>     and internal to tegra_display_init(), the DT is searched for LCD
>     controller nodes, and if any are found, they're matched to the LCD
>     driver registered by the first call above.
> 
> 
> Yes that sounds great, but again we don't really have this
> infrastructure in U-Boot. We would be inventing it just for Tegra, and I
> would prefer to wait until the device model stuff is done before being
> too fancy.

What is "the device model stuff" you mention?

> We don't have an HDMI driver at present, so perhaps if/when that appears
> in U-Boot it would be a good time to add support for that?

Certainly adding code for HDMI can wait until later. However, I do think
that we should use the correct ifdefs up-front, so that e.g. adding HDMI
support only means adding a bunch of code, not going through the
existing code and untangling conflated ifdefs.