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

Stephen Warren
2012-07-23T20:25:04Z

On 07/10/2012 10:58 PM, Simon Glass wrote:
> Hi Stephen,
>
> On Fri, Jun 15, 2012 at 1:47 AM, Stephen Warren <swarren@wwwdotorg.org
> <mailto:swarren@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.