On 12/05/2013 05:25 AM, Hiroshi Doyu wrote:
> The later Tegra SoC(>= T124) has more registers for
> MC_SMMU_TRANSLATION_ENABLE_*. Now those info is provided as platfrom
> data. If those varies a lot on SoCs in the future, we can consider
> putting them into DT later.
This shouldn't be called "platform data", since that phrase already has
an existing different meaning within Linux. Instead, perhaps
"SoC-specific configuration" or "HW-specific configuration" (or
s/configuration/parameters/).
> diff --git a/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt
> b/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt
> Required properties in the IOMMU node:
> -- compatible : "nvidia,tegra30-smmu"
> -- reg : Should contain 3 register banks(address and length) for each
> +- compatible : "nvidia,tegra124-smmu", "nvidia,tegra30-smmu"
> +- reg : Can contain multiple register banks(address and length) for each
Not all DTs should include both. I would phrase this as:
- compatible : One of the following:
- nvidia,tegra30-smmu
- nvidia,tegra124-smmu
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> +struct smmu_platform_data {
> + int asids; /* number of asids */
> + int nr_xlats; /* number of translation_enable registers */
> +};
Shouldn't both or neither of those fields be prefixed with "nr_" for
consistency?
> +static const struct smmu_platform_data tegra124_smmu_pdata = {
> + .asids = 128,
> + .nr_xlats = 4,
> +};
> +
> +static struct of_device_id tegra_smmu_of_match[] = {
> + { .compatible = "nvidia,tegra124-smmu", .data = &tegra124_smmu_pdata, },
> + { .compatible = "nvidia,tegra30-smmu", },
Where is tegra30_smmu_pdata, and why doesn't this table entry point at
it? That would avoid conditional code elsewhere.
> @@ -1250,20 +1269,29 @@ static int tegra_smmu_probe(struct platform_device
> *pdev)
> + smmu->nr_xlats = nr_xlats;
Why not just:
smmu->pdata = pdata;
That would avoid having to change this code to copy new fields every
time they get added.
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