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

[Manish Narani]

Hi Shawn,

> -----Original Message-----
> From: Shawn Lin [mailto:shawn.lin at rock-chips.com]
> Sent: Thursday, March 29, 2018 12:57 PM
> To: naranimanish at gmail.com
> Cc: adrian.hunter at intel.com; michal.simek at xilinx.com;
> ulf.hansson at linaro.org; linux-mmc at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org; shawn.lin at rock-
> chips.com; Manish Narani <MNARANI at xilinx.com>
> Subject: Re: [RFC PATCH] sdhci: arasan: Add runtime PM support
> 
> On 2018/3/29 13:48, 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>
> > ---
> >   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.
> > + */
> > +static int sdhci_arasan_runtime_suspend(struct device *dev) {
> 
> Would you help take care of cqhci_suspend?
Yes, sure. Will take care of this in next version of patch.

> 
> > +	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
> > + */
> > +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;
> > +
> 
> Ditto, for cqhci_resume.
Yes, okay.

Thanks,
Manish

> 
> > +	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:
> >