[RFC PATCH] sdhci: arasan: Add runtime PM support

[Adrian Hunter]

On 29/03/18 08:48, naranimanish at gmail.com wrote:
> From: Manish Narani <mnarani at xilinx.com>
> 
> This patch adds runtime PM support in Arasan SD driver.
> 
> Signed-off-by: Manish Narani <mnarani at xilinx.com>

Just a couple of comments about style.

> ---
>  drivers/mmc/host/sdhci-of-arasan.c | 83 +++++++++++++++++++++++++++++++++++++-
>  1 file changed, 81 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index c33a5f7..47196b5 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -23,6 +23,7 @@
>  #include <linux/mfd/syscon.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/phy/phy.h>
>  #include <linux/regmap.h>
>  #include <linux/of.h>
> @@ -349,6 +350,75 @@ static const struct sdhci_pltfm_data sdhci_arasan_cqe_pdata = {
>  			SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
>  };
>  
> +#ifdef CONFIG_PM
> +/**
> + * sdhci_arasan_runtime_suspend - Suspend method for the driver
> + * @dev:	Address of the device structure
> + * Returns 0 on success and error value on error
> + *
> + * Put the device in a low power state.
> + */

Kernel style is not to put kerneldoc on callback functions.

> +static int sdhci_arasan_runtime_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct sdhci_host *host = platform_get_drvdata(pdev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
> +	int ret;
> +
> +	ret = sdhci_runtime_suspend_host(host);
> +	if (ret)
> +		return ret;
> +
> +	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
> +		mmc_retune_needed(host->mmc);
> +
> +	clk_disable(pltfm_host->clk);
> +	clk_disable(sdhci_arasan->clk_ahb);
> +
> +	return 0;
> +}
> +
> +/**
> + * sdhci_arasan_runtime_resume - Resume method for the driver
> + * @dev:	Address of the device structure
> + * Returns 0 on success and error value on error
> + *
> + * Resume operation after suspend
> + */

Kernel style is not to put kerneldoc on callback functions.

> +static int sdhci_arasan_runtime_resume(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct sdhci_host *host = platform_get_drvdata(pdev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
> +	int ret;
> +
> +	ret = clk_enable(sdhci_arasan->clk_ahb);
> +	if (ret) {
> +		dev_err(dev, "Cannot enable AHB clock.\n");
> +		return ret;
> +	}
> +
> +	ret = clk_enable(pltfm_host->clk);
> +	if (ret) {
> +		dev_err(dev, "Cannot enable SD clock.\n");
> +		return ret;
> +	}
> +
> +	ret = sdhci_runtime_resume_host(host);
> +	if (ret)
> +		goto out;
> +
> +	return 0;
> +out:
> +	clk_disable(pltfm_host->clk);
> +	clk_disable(sdhci_arasan->clk_ahb);
> +
> +	return ret;
> +}
> +#endif /* ! CONFIG_PM */
> +
>  #ifdef CONFIG_PM_SLEEP
>  /**
>   * sdhci_arasan_suspend - Suspend method for the driver
> @@ -443,8 +513,11 @@ 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);
> +static const struct dev_pm_ops sdhci_arasan_dev_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(sdhci_arasan_suspend, sdhci_arasan_resume)
> +	SET_RUNTIME_PM_OPS(sdhci_arasan_runtime_suspend,
> +			   sdhci_arasan_runtime_resume, NULL)
> +};
>  
>  static const struct of_device_id sdhci_arasan_of_match[] = {
>  	/* SoC-specific compatible strings w/ soc_ctl_map */
> @@ -806,6 +879,12 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_add_host;
>  
> +	pm_runtime_set_active(&pdev->dev);
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_set_autosuspend_delay(&pdev->dev, 2000);
> +	pm_runtime_mark_last_busy(&pdev->dev);
> +	pm_runtime_use_autosuspend(&pdev->dev);
> +
>  	return 0;
>  
>  err_add_host:
>