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Subject: Re: [PATCH 2/2] mmc: tegra: Implement periodic pad calibration
To:     Aapo Vienamo <avienamo@nvidia.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>
Cc:     linux-mmc@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1534757013-4524-1-git-send-email-avienamo@nvidia.com>
 <1534757013-4524-3-git-send-email-avienamo@nvidia.com>
From:   Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
 Business Identity Code: 0357606 - 4, Domiciled in Helsinki
Message-ID: <3bdbaef6-522d-92ea-c0d1-1aea9fd069d9@intel.com>
Date:   Wed, 22 Aug 2018 13:56:57 +0300
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On 20/08/18 12:23, Aapo Vienamo wrote:
> Rerun the pad calibration procedure before sdhci_request() if
> the 100 ms recalibration interval has been exceeded.
> 
> Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-tegra.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 94624ec..ef18a0c 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -30,6 +30,7 @@
>  #include <linux/mmc/mmc.h>
>  #include <linux/mmc/slot-gpio.h>
>  #include <linux/gpio/consumer.h>
> +#include <linux/ktime.h>
>  
>  #include "sdhci-pltfm.h"
>  
> @@ -122,6 +123,7 @@ struct sdhci_tegra {
>  	struct pinctrl_state *pinctrl_state_1v8;
>  
>  	struct sdhci_tegra_autocal_offsets autocal_offsets;
> +	ktime_t last_calib;
>  
>  	u32 default_tap;
>  	u32 default_trim;
> @@ -533,6 +535,22 @@ static void tegra_sdhci_parse_pad_autocal_dt(struct sdhci_host *host)
>  		autocal->pull_down_hs400 = autocal->pull_down_1v8;
>  }
>  
> +static void tegra_sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
> +	ktime_t since_calib = ktime_sub(ktime_get(), tegra_host->last_calib);
> +
> +	/* 100 ms calibration interval is specified in the TRM */
> +	if (ktime_to_ms(since_calib) > 100) {
> +		tegra_sdhci_pad_autocalib(host);
> +		tegra_host->last_calib = ktime_get();
> +	}
> +
> +	sdhci_request(mmc, mrq);
> +}
> +
>  static void tegra_sdhci_parse_tap_and_trim(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -1014,6 +1032,10 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
>  				sdhci_tegra_start_signal_voltage_switch;
>  	}
>  
> +	/* Hook to periodically rerun pad calibration */
> +	if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
> +		host->mmc_host_ops.request = tegra_sdhci_request;
> +
>  	host->mmc_host_ops.hs400_enhanced_strobe =
>  			tegra_sdhci_hs400_enhanced_strobe;
>  
>