Re: [PATCH v3 3/3] mmc: sdhci-of-arasan: add runtime pm support

[Michal Simek <michal.simek@xilinx.com>]

Hi,

On 10/20/2015 09:05 AM, Shawn Lin wrote:
> This patch add runtime_suspend and runtime_resume for
> sdhci-of-arasan. Currently we also suspend phy at
> runtime_suspend for power-saving.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> ---
> 
> Changes in v2: None
> 
>  drivers/mmc/host/sdhci-of-arasan.c | 80 ++++++++++++++++++++++++++++++++++++--
>  1 file changed, 77 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 85bd0f9d..579f7bb 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -30,6 +30,8 @@
>  #define CLK_CTRL_TIMEOUT_MASK		(0xf << CLK_CTRL_TIMEOUT_SHIFT)
>  #define CLK_CTRL_TIMEOUT_MIN_EXP	13
>  
> +#define ARASAN_RPM_DELAY_MS		50
> +
>  /**
>   * struct sdhci_arasan_data
>   * @clk_ahb:	Pointer to the AHB clock
> @@ -183,8 +185,70 @@ static int sdhci_arasan_resume(struct device *dev)
>  }
>  #endif /* ! CONFIG_PM_SLEEP */
>  
> -static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
> -			 sdhci_arasan_resume);
> +
> +#ifdef CONFIG_PM
> +static int sdhci_arasan_runtime_suspend(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
> +	int ret;
> +
> +	ret = sdhci_runtime_suspend_host(host);
> +	if (ret)
> +		return ret;
> +
> +	if (!IS_ERR(sdhci_arasan->phy)) {
> +		ret = sdhci_arasan_suspend_phy(sdhci_arasan->phy);
> +		if (ret) {
> +			dev_err(dev, "Cannot suspend phy at runtime.\n");
> +			sdhci_runtime_resume_host(host);
> +			return ret;
> +		}
> +	}
> +
> +	clk_disable_unprepare(sdhci_arasan->clk_ahb);
> +	clk_disable_unprepare(pltfm_host->clk);
> +
> +	return 0;
> +}
> +
> +static int sdhci_arasan_runtime_resume(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
> +	int ret;
> +
> +	clk_prepare_enable(pltfm_host->clk);
> +	clk_prepare_enable(sdhci_arasan->clk_ahb);
> +
> +	if (!IS_ERR(sdhci_arasan->phy)) {
> +		ret = sdhci_arasan_resume_phy(sdhci_arasan->phy);
> +		if (ret) {
> +			dev_err(dev, "Cannot resume phy at runtime.\n");
> +			clk_disable_unprepare(sdhci_arasan->clk_ahb);
> +			clk_disable_unprepare(pltfm_host->clk);
> +			return ret;
> +		}
> +	}
> +
> +	return sdhci_runtime_resume_host(host);
> +}
> +#endif
> +
> +#ifdef CONFIG_PM
> +static const struct dev_pm_ops sdhci_arasan_pmops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(sdhci_arasan_suspend, sdhci_arasan_resume)
> +	SET_RUNTIME_PM_OPS(sdhci_arasan_runtime_suspend,
> +				sdhci_arasan_runtime_resume, NULL)
> +};
> +
> +#define SDHCI_ARASAN_PMOPS (&sdhci_arasan_pmops)
> +
> +#else
> +#define SDHCI_ARASAN_PMOPS NULL
> +#endif

This is completely wrong. SET_SYSTEM_SLEEP_PM_OPS, SET_RUNTIME_PM_OPS
have both declarations for !PM_SLEEP, !PM cases. It means you can remove
this ifdef mess.

I was doing experiment with your code and you need to add __maybe_unused
for functions which are not used when certain functions are not wired
for !PM, !PM_SLEEP cases.

Something like this should be added to any SDHCI header. (or Using
macros). Definitely this should be tested for all combinations.
#if !defined(CONFIG_PM)
static inline int sdhci_suspend_host(struct sdhci_host *host)	{ return -1; }
static inline int sdhci_resume_host(struct sdhci_host *host)	{ return -1; }
static inline int sdhci_runtime_suspend_host(struct sdhci_host *host)	{
return -1; }
static inline int sdhci_runtime_resume_host(struct sdhci_host *host)	{
return -1; }
#endif


>  
>  static int sdhci_arasan_probe(struct platform_device *pdev)
>  {
> @@ -272,6 +336,11 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>  		goto clk_disable_all;
>  	}
>  
> +	pm_runtime_set_autosuspend_delay(&pdev->dev, ARASAN_RPM_DELAY_MS);
> +	pm_runtime_use_autosuspend(&pdev->dev);
> +	pm_runtime_enable(&pdev->dev);
> +	pm_suspend_ignore_children(&pdev->dev, 1);
> +
>  	ret = sdhci_add_host(host);
>  	if (ret)
>  		goto err_pltfm_free;
> @@ -279,6 +348,7 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_pltfm_free:
> +	pm_runtime_disable(&pdev->dev);
>  	sdhci_pltfm_free(pdev);
>  clk_disable_all:
>  	clk_disable_unprepare(clk_xin);
> @@ -297,6 +367,10 @@ static int sdhci_arasan_remove(struct platform_device *pdev)
>  	if (!IS_ERR(sdhci_arasan->phy))
>  		phy_exit(sdhci_arasan->phy);
>  
> +	pm_runtime_get_sync(&pdev->dev);
> +	pm_runtime_dont_use_autosuspend(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +
>  	clk_disable_unprepare(sdhci_arasan->clk_ahb);
>  
>  	return sdhci_pltfm_unregister(pdev);
> @@ -314,7 +388,7 @@ static struct platform_driver sdhci_arasan_driver = {
>  	.driver = {
>  		.name = "sdhci-arasan",
>  		.of_match_table = sdhci_arasan_of_match,
> -		.pm = &sdhci_arasan_dev_pm_ops,
> +		.pm = SDHCI_ARASAN_PMOPS,

Keep origin name here. No reason for this macro at all.

>  	},
>  	.probe = sdhci_arasan_probe,
>  	.remove = sdhci_arasan_remove,
> 

Thanks,
Michal