From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Warren <swarren@nvidia.com>
Date: Thu, 19 Jan 2012 14:58:53 -0700
Subject: [U-Boot] [PATCH v2 09/20] tegra: Add EMC support for optimal
	memory timings
In-Reply-To: <1326490535-3461-10-git-send-email-sjg@chromium.org>
References: <1326490535-3461-1-git-send-email-sjg@chromium.org>
	<1326490535-3461-10-git-send-email-sjg@chromium.org>
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On 01/13/2012 02:35 PM, Simon Glass wrote:
> From: Jimmy Zhang <jimmzhang@nvidia.com>
> 
> Add support for setting up the memory controller parameters. Boards
> can set up an appropriate table in the device tree.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> Changes in v2:
> - Add debug() output to EMC
> - Move EMC tables to device tree

This patch doesn't fully handle the device tree binding. There are two
alternatives:

two-level:

emc {
    ...
    emc-table at 190000 {
        compatible = "nvidia,tegra20-emc-table";
        ...
    };
    emc-table at 380000 {
        compatible = "nvidia,tegra20-emc-table";
        ...
    };
};

three-level:

emc {
    ...
    nvidia,use-ram-code;
    emc-tables {
        nvidia,ram-code = <0>;
        emc-table at 190000 {
            compatible = "nvidia,tegra20-emc-table";
            ...
        };
        emc-table at 380000 {
            compatible = "nvidia,tegra20-emc-table";
            ...
        };
    };
    emc-tables {
        nvidia,ram-code = <1>;
        emc-table at 190000 {
            compatible = "nvidia,tegra20-emc-table";
            ...
        };
        emc-table at 380000 {
            compatible = "nvidia,tegra20-emc-table";
            ...
        };
    };
};

Even if we don't fully implement support for both, we should detect the
unsupported and flag an explicit error. But, it's pretty easy to support
the other format.

BTW, does:

+               node = fdtdec_next_compatible(blob, node,
+                               COMPAT_NVIDIA_TEGRA20_EMC_TABLE);

limit itself to searching child nodes?

-- 
nvpublic