Re: [PATCH 16/40] mmc: tegra: Disable card clock during pad calibration

[Thierry Reding]

On Wed, Aug 01, 2018 at 07:32:06PM +0300, Aapo Vienamo wrote:
> Disable the card clock during automatic pad drive strength calibration
> and re-enable it afterwards.
> 
> Signed-off-by: Aapo Vienamo <avien...@nvidia.com>
> ---
>  drivers/mmc/host/sdhci-tegra.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 9e22fec..c2b388b 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -260,11 +260,35 @@ static void tegra_sdhci_configure_cal_pad(struct 
> sdhci_host *host, bool enable)
>       }
>  }
>  
> +static bool tegra_sdhci_configure_card_clk(struct sdhci_host *host, bool 
> enable)
> +{
> +     bool orig_enabled;

I don't see a need for the orig_ prefix. If you're concerned that
"enable" and "enabled" might clash, perhaps "status" would be a better
name?

Thierry

> +     u32 reg;
> +
> +     reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +     orig_enabled = !!(reg & SDHCI_CLOCK_CARD_EN);
> +
> +     if (orig_enabled == enable)
> +             return orig_enabled;
> +
> +     if (enable)
> +             reg |= SDHCI_CLOCK_CARD_EN;
> +     else
> +             reg &= ~SDHCI_CLOCK_CARD_EN;
> +
> +     sdhci_writew(host, reg, SDHCI_CLOCK_CONTROL);
> +
> +     return orig_enabled;
> +}
> +
>  static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
>  {
> +     bool card_clk_enabled;
>       u32 reg;
>       int ret;
>  
> +     card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);
> +
>       tegra_sdhci_configure_cal_pad(host, true);
>  
>       reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
> @@ -278,6 +302,8 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host 
> *host)
>  
>       tegra_sdhci_configure_cal_pad(host, false);
>  
> +     tegra_sdhci_configure_card_clk(host, card_clk_enabled);
> +
>       if (ret)
>               dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
>  }
> -- 
> 2.7.4
> 

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