Re: [PATCH v2] mmc: sdhci-xenon: add runtime pm support and reimplement standby

[Adrian Hunter <adrian.hunter@intel.com>]

On 28/08/17 21:55, Zhoujie Wu wrote:
> Enable runtime pm support for xenon controller, which uses 50ms
> auto runtime suspend by default.
> Reimplement system standby based on runtime pm API.
> Introduce restore_needed to restore the Xenon specific registers
> when resume.
> 
> Signed-off-by: Zhoujie Wu <zjwu@marvell.com>

There are a few small comments below.

> ---
> v2: Combined two previous patches(runtime pm support and reimplement standby)
> to one according to the suggestion from Adrian.
> 
>  drivers/mmc/host/sdhci-xenon.c | 76 ++++++++++++++++++++++++++++++++----------
>  drivers/mmc/host/sdhci-xenon.h |  1 +
>  2 files changed, 60 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> index 306ffaf..f97a78e 100644
> --- a/drivers/mmc/host/sdhci-xenon.c
> +++ b/drivers/mmc/host/sdhci-xenon.c
> @@ -18,6 +18,8 @@
>  #include <linux/ktime.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/pm.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "sdhci-pltfm.h"
>  #include "sdhci-xenon.h"
> @@ -506,13 +508,24 @@ static int xenon_probe(struct platform_device *pdev)
>  	if (err)
>  		goto err_clk;
>  
> +	pm_runtime_get_noresume(&pdev->dev);
> +	pm_runtime_set_active(&pdev->dev);
> +	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
> +	pm_runtime_use_autosuspend(&pdev->dev);
> +	pm_runtime_enable(&pdev->dev);

I would expect to see a corresponding pm_runtime_disable() in xenon_remove()
e.g.

	pm_runtime_get_sync(dev);
	pm_runtime_disable(dev);
	pm_runtime_put_noidle(dev);

	sdhci_remove_host(host, 0);

> +	pm_suspend_ignore_children(&pdev->dev, 1);
> +
>  	err = sdhci_add_host(host);
>  	if (err)
>  		goto remove_sdhc;
>  
> +	pm_runtime_put_autosuspend(&pdev->dev);
> +
>  	return 0;
>  
>  remove_sdhc:
> +	pm_runtime_disable(&pdev->dev);
> +	pm_runtime_put_noidle(&pdev->dev);
>  	xenon_sdhc_unprepare(host);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
> @@ -542,40 +555,69 @@ static int xenon_suspend(struct device *dev)
>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
>  	int ret;
>  
> -	ret = sdhci_suspend_host(host);
> -	if (ret)
> -		return ret;
> +	ret = pm_runtime_force_suspend(dev);
>  
> -	clk_disable_unprepare(pltfm_host->clk);
> +	priv->restore_needed = true;
>  	return ret;
>  }
> +#endif
>  
> -static int xenon_resume(struct device *dev)
> +#ifdef CONFIG_PM
> +static int xenon_runtime_suspend(struct device *dev)
>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
>  	int ret;
>  
> -	ret = clk_prepare_enable(pltfm_host->clk);
> -	if (ret)
> -		return ret;
> +	ret = sdhci_runtime_suspend_host(host);

Return on error.

> +
> +	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
> +		mmc_retune_needed(host->mmc);
>  
> +	clk_disable_unprepare(pltfm_host->clk);
>  	/*
> -	 * If SoCs power off the entire Xenon, registers setting will
> -	 * be lost.
> -	 * Re-configure Xenon specific register to enable current SDHC
> +	 * Need to update the priv->clock here, or when runtime resume
> +	 * back, phy don't aware the clock change and won't adjust phy
> +	 * which will cause cmd err
>  	 */
> -	ret = xenon_sdhc_prepare(host);
> -	if (ret)
> +	priv->clock = 0;
> +	return ret;
> +}
> +
> +static int xenon_runtime_resume(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
> +	int ret;
> +
> +	ret = clk_prepare_enable(pltfm_host->clk);
> +	if (ret) {
> +		dev_err(dev, "can't enable mainck\n");
>  		return ret;
> +	}
> +
> +	if (priv->restore_needed) {
> +		xenon_sdhc_prepare(host);

Check for error and then clk_disable_unprepare()

> +		priv->restore_needed = false;
> +	}
>  
> -	return sdhci_resume_host(host);
> +	return sdhci_runtime_resume_host(host);

Check for error and then clk_disable_unprepare()

>  }
> -#endif
> +#endif /* CONFIG_PM */
> +
> +static const struct dev_pm_ops sdhci_xenon_dev_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(xenon_suspend,
> +				pm_runtime_force_resume)
> +	SET_RUNTIME_PM_OPS(xenon_runtime_suspend,
> +			   xenon_runtime_resume,
> +			   NULL)
> +};
>  
> -static SIMPLE_DEV_PM_OPS(xenon_pmops, xenon_suspend, xenon_resume);

This leaves two blank lines.

>  
>  static const struct of_device_id sdhci_xenon_dt_ids[] = {
>  	{ .compatible = "marvell,armada-ap806-sdhci",},
> @@ -589,7 +631,7 @@ static int xenon_resume(struct device *dev)
>  	.driver	= {
>  		.name	= "xenon-sdhci",
>  		.of_match_table = sdhci_xenon_dt_ids,
> -		.pm = &xenon_pmops,
> +		.pm = &sdhci_xenon_dev_pm_ops,
>  	},
>  	.probe	= xenon_probe,
>  	.remove	= xenon_remove,
> diff --git a/drivers/mmc/host/sdhci-xenon.h b/drivers/mmc/host/sdhci-xenon.h
> index 01937f1..2bc0510 100644
> --- a/drivers/mmc/host/sdhci-xenon.h
> +++ b/drivers/mmc/host/sdhci-xenon.h
> @@ -91,6 +91,7 @@ struct xenon_priv {
>  	 */
>  	void		*phy_params;
>  	struct xenon_emmc_phy_regs *emmc_phy_regs;
> +	bool restore_needed;
>  };
>  
>  int xenon_phy_adj(struct sdhci_host *host, struct mmc_ios *ios);
>