[U-Boot] [PATCH v4 19/23] tegra: Add EMC settings for Seaboard

[Stephen Warren <swarren@wwwdotorg.org>]

On 04/05/2012 03:55 PM, Simon Glass wrote:
> From: Jimmy Zhang <jimmzhang@nvidia.com>
> 
> Set Seaboard to optimal memory settings based on the SOC in use (T20 or T25).
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> Changes in v2:
> - Move EMC tables to device tree
> - Removed check for nominal voltage (not needed as it is done just before)
> 
> Changes in v3:
> - Add better error reporting when EMC setup fails
> 
> Changes in v4:
> - Remove support for T20 memory timings

> diff --git a/board/nvidia/common/emc.c b/board/nvidia/common/emc.c

> +/* This rate is hard-coded for now, until fdt provides them */
> +#define EMC_SDRAM_RATE_T25	(380000 * 2 * 1000)
> +
> +int board_emc_init(void)
> +{
> +	unsigned rate;
> +
> +	switch (tegra_get_chip_type()) {
> +	default:
> +	case TEGRA_SOC_T20:
> +		debug("%s: EMC timings not supported for T20 Seaboard\n",
> +		      __func__);

This isn't Seaboard-specific code, so the string shouldn't say
"Seaboard" there.

Why not support Tegra20? Many/all of the other Tegra boards U-Boot
supports are Tegra20 not Tegra25.

Presumably this code doesn't blow up if the EMC tables aren't in the
.dts file; the code should use the tables if they're present, otherwise
be a no-op.

> +		return -1;
> +	case TEGRA_SOC_T25:
> +		rate  = EMC_SDRAM_RATE_T25;
> +		break;
> +	}
> +	return tegra_set_emc(gd->fdt_blob, rate);
> +}