[U-Boot] [PATCH v4 3/3] ARM: tegra: Add support for nyan-big board

[Stephen Warren]

On 11/26/2014 01:46 PM, Simon Glass wrote:
> From: Allen Martin <amartin at nvidia.com>
>
> Nyan-big is a Tegra124 clamshell board that is very similar to venice2, but
> it has a different panel, the sdcard cd and wp sense are flipped, and it has
> a different revision of the AS3722 PMIC.
>
> This is the Acer Chromebook 13 CB5-311-T7NN (13.3-inch HD, NVIDIA
> Tegra K1, 2GB). The display is not currently supported, so it should
> boot on other nyan-based Chromebooks also, but only the device tree for
> nyan-big is provided here.
>
> The device tree file is from Linux but with features removed which are
> unlikely to be supported in U-Boot soon (regulators, pinmux). Also the
> addresses are updated to 32-bit.

At a quick glance, the naming seems fine here, so I'm OK with the patch.

I'd like to see tegra-pinmux-scripts updated to suport this board, but 
don't hold up this patch for that; just a nice to have when it can 
happen. Perhaps Allen can also double-check that the pinmux data in this 
patch exactly matches the NVIDIA syseng spreadsheet for this board.

I'd like Allen to explicitly comment on the reset GPIO difference and 
why it occurred. I'd like to see that happen before the patch is merged, 
so the pinmux data can be correct. Perhaps it's simply due to:

> diff --git a/board/nvidia/nyan-big/nyan-big.c b/board/nvidia/nyan-big/nyan-big.c

> +void pinmux_init(void)
> +{
> +	pinmux_set_tristate_input_clamping();

Apparently, we should explicitly not be doing that, even though I was 
earlier told by our syseng team we explicitly should be doing that. 
Removing that call (or explicitly reverting it) might make the 
difference go away?