Subject: Re: [PATCH v16 22/40] mmc: sdhci-tegra: Add runtime PM and OPP
 support
To:     Dmitry Osipenko <digetx@gmail.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Viresh Kumar <vireshk@kernel.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Peter De Schrijver <pdeschrijver@nvidia.com>,
        Mikko Perttunen <mperttunen@nvidia.com>,
        Lee Jones <lee.jones@linaro.org>,
        =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= <u.kleine-koenig@pengutronix.de>,
        Nishanth Menon <nm@ti.com>,
        Michael Turquette <mturquette@baylibre.com>
Cc:     linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-pm@vger.kernel.org, linux-pwm@vger.kernel.org,
        linux-mmc@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-clk@vger.kernel.org, David Heidelberg <david@ixit.cz>
References: <20211130232347.950-1-digetx@gmail.com>
 <20211130232347.950-23-digetx@gmail.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: <fc60f593-cd74-558d-785f-5f0d2ba179cf@intel.com>
Date:   Thu, 2 Dec 2021 10:16:32 +0200
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On 01/12/2021 01:23, Dmitry Osipenko wrote:
> The SDHCI on Tegra belongs to the core power domain and we're going to
> enable GENPD support for the core domain. Now SDHCI must be resumed using
> runtime PM API in order to initialize the SDHCI power state. The SDHCI
> clock rate must be changed using OPP API that will reconfigure the power
> domain performance state in accordance to the rate. Add runtime PM and OPP
> support to the SDHCI driver.
> 
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

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

> ---
>  drivers/mmc/host/sdhci-tegra.c | 81 +++++++++++++++++++++++++++-------
>  1 file changed, 65 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index a5001875876b..6435a75142a6 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -15,6 +15,8 @@
>  #include <linux/of.h>
>  #include <linux/of_device.h>
>  #include <linux/pinctrl/consumer.h>
> +#include <linux/pm_opp.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/reset.h>
>  #include <linux/mmc/card.h>
> @@ -24,6 +26,8 @@
>  #include <linux/gpio/consumer.h>
>  #include <linux/ktime.h>
>  
> +#include <soc/tegra/common.h>
> +
>  #include "sdhci-pltfm.h"
>  #include "cqhci.h"
>  
> @@ -760,7 +764,9 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
> +	struct device *dev = mmc_dev(host->mmc);
>  	unsigned long host_clk;
> +	int err;
>  
>  	if (!clock)
>  		return sdhci_set_clock(host, clock);
> @@ -778,7 +784,12 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>  	 * from clk_get_rate() is used.
>  	 */
>  	host_clk = tegra_host->ddr_signaling ? clock * 2 : clock;
> -	clk_set_rate(pltfm_host->clk, host_clk);
> +
> +	err = dev_pm_opp_set_rate(dev, host_clk);
> +	if (err)
> +		dev_err(dev, "failed to set clk rate to %luHz: %d\n",
> +			host_clk, err);
> +
>  	tegra_host->curr_clk_rate = host_clk;
>  	if (tegra_host->ddr_signaling)
>  		host->max_clk = host_clk;
> @@ -1705,7 +1716,6 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
>  				   "failed to get clock\n");
>  		goto err_clk_get;
>  	}
> -	clk_prepare_enable(clk);
>  	pltfm_host->clk = clk;
>  
>  	tegra_host->rst = devm_reset_control_get_exclusive(&pdev->dev,
> @@ -1716,15 +1726,24 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
>  		goto err_rst_get;
>  	}
>  
> -	rc = reset_control_assert(tegra_host->rst);
> +	rc = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
>  	if (rc)
>  		goto err_rst_get;
>  
> +	pm_runtime_enable(&pdev->dev);
> +	rc = pm_runtime_resume_and_get(&pdev->dev);
> +	if (rc)
> +		goto err_pm_get;
> +
> +	rc = reset_control_assert(tegra_host->rst);
> +	if (rc)
> +		goto err_rst_assert;
> +
>  	usleep_range(2000, 4000);
>  
>  	rc = reset_control_deassert(tegra_host->rst);
>  	if (rc)
> -		goto err_rst_get;
> +		goto err_rst_assert;
>  
>  	usleep_range(2000, 4000);
>  
> @@ -1736,8 +1755,11 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
>  
>  err_add_host:
>  	reset_control_assert(tegra_host->rst);
> +err_rst_assert:
> +	pm_runtime_put_sync_suspend(&pdev->dev);
> +err_pm_get:
> +	pm_runtime_disable(&pdev->dev);
>  err_rst_get:
> -	clk_disable_unprepare(pltfm_host->clk);
>  err_clk_get:
>  	clk_disable_unprepare(tegra_host->tmclk);
>  err_power_req:
> @@ -1756,19 +1778,38 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
>  
>  	reset_control_assert(tegra_host->rst);
>  	usleep_range(2000, 4000);
> -	clk_disable_unprepare(pltfm_host->clk);
> -	clk_disable_unprepare(tegra_host->tmclk);
>  
> +	pm_runtime_put_sync_suspend(&pdev->dev);
> +	pm_runtime_force_suspend(&pdev->dev);
> +
> +	clk_disable_unprepare(tegra_host->tmclk);
>  	sdhci_pltfm_free(pdev);
>  
>  	return 0;
>  }
>  
> -#ifdef CONFIG_PM_SLEEP
> -static int __maybe_unused sdhci_tegra_suspend(struct device *dev)
> +static int __maybe_unused sdhci_tegra_runtime_suspend(struct device *dev)
>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +
> +	clk_disable_unprepare(pltfm_host->clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused sdhci_tegra_runtime_resume(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +
> +	return clk_prepare_enable(pltfm_host->clk);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int sdhci_tegra_suspend(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
>  	int ret;
>  
>  	if (host->mmc->caps2 & MMC_CAP2_CQE) {
> @@ -1783,17 +1824,22 @@ static int __maybe_unused sdhci_tegra_suspend(struct device *dev)
>  		return ret;
>  	}
>  
> -	clk_disable_unprepare(pltfm_host->clk);
> +	ret = pm_runtime_force_suspend(dev);
> +	if (ret) {
> +		sdhci_resume_host(host);
> +		cqhci_resume(host->mmc);
> +		return ret;
> +	}
> +
>  	return 0;
>  }
>  
> -static int __maybe_unused sdhci_tegra_resume(struct device *dev)
> +static int sdhci_tegra_resume(struct device *dev)
>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
> -	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	int ret;
>  
> -	ret = clk_prepare_enable(pltfm_host->clk);
> +	ret = pm_runtime_force_resume(dev);
>  	if (ret)
>  		return ret;
>  
> @@ -1812,13 +1858,16 @@ static int __maybe_unused sdhci_tegra_resume(struct device *dev)
>  suspend_host:
>  	sdhci_suspend_host(host);
>  disable_clk:
> -	clk_disable_unprepare(pltfm_host->clk);
> +	pm_runtime_force_suspend(dev);
>  	return ret;
>  }
>  #endif
>  
> -static SIMPLE_DEV_PM_OPS(sdhci_tegra_dev_pm_ops, sdhci_tegra_suspend,
> -			 sdhci_tegra_resume);
> +static const struct dev_pm_ops sdhci_tegra_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(sdhci_tegra_runtime_suspend, sdhci_tegra_runtime_resume,
> +			   NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(sdhci_tegra_suspend, sdhci_tegra_resume)
> +};
>  
>  static struct platform_driver sdhci_tegra_driver = {
>  	.driver		= {
>