[U-Boot] [PATCH 11/23] ARM: tegra: Implement powergate support

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/18/2014 01:16 AM, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> Implement the powergate API that allows various power partitions to be
> power up and down.

> diff --git a/arch/arm/cpu/tegra-common/powergate.c b/arch/arm/cpu/tegra-common/powergate.c

> +static int tegra_powergate_set(enum tegra_powergate id, bool state)

> +	writel(PWRGATE_TOGGLE_START | id, NV_PA_PMC_BASE + PWRGATE_TOGGLE);

Since the power-down/up is an asynchronous operation, don't you need to 
wait for it to complete here?

> +	return 0;
> +}

> +static int tegra_powergate_remove_clamping(enum tegra_powergate id)
> +{
> +	unsigned long value;
> +
> +	if (id == TEGRA_POWERGATE_VDEC)
> +		value = 1 << TEGRA_POWERGATE_PCIE;
> +	else if (id == TEGRA_POWERGATE_PCIE)
> +		value = 1 << TEGRA_POWERGATE_VDEC;
> +	else
> +		value = 1 << id;

A comment indicating why there's a special case here would be useful.

Isn't the special-case (HW design bug) restricted to Tegra20, or did it 
carry over into later chips in order to maintain HW register compatibility?

> diff --git a/arch/arm/include/asm/arch-tegra/powergate.h b/arch/arm/include/asm/arch-tegra/powergate.h

> +enum tegra_powergate {
> +	TEGRA_POWERGATE_CPU,
> +	TEGRA_POWERGATE_3D,
> +	TEGRA_POWERGATE_VENC,
> +	TEGRA_POWERGATE_PCIE,
> +	TEGRA_POWERGATE_VDEC,
> +	TEGRA_POWERGATE_L2,
> +	TEGRA_POWERGATE_MPE,
> +	TEGRA_POWERGATE_HEG,
> +	TEGRA_POWERGATE_SATA,
> +	TEGRA_POWERGATE_CPU1,
> +	TEGRA_POWERGATE_CPU2,
> +	TEGRA_POWERGATE_CPU3,
> +	TEGRA_POWERGATE_CELP,
> +	TEGRA_POWERGATE_3D1,
> +};

I thought the list of partitions varied a bit by chip?

Overall the code structure looks good, and on the condition I'm wrong 
about the variations between chips,
Acked-by: Stephen Warren <swarren@nvidia.com>