diff mbox series

[V1] mmc: tegra: add sdhci tegra suspend and resume

Message ID 1554182853-31612-1-git-send-email-skomatineni@nvidia.com (mailing list archive)
State New, archived
Headers show
Series [V1] mmc: tegra: add sdhci tegra suspend and resume | expand

Commit Message

Sowjanya Komatineni April 2, 2019, 5:27 a.m. UTC
This patch adds suspend and resume PM ops for tegra SDHCI.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 45 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

Comments

Thierry Reding April 2, 2019, 2:59 p.m. UTC | #1
On Mon, Apr 01, 2019 at 10:27:33PM -0700, Sowjanya Komatineni wrote:
> This patch adds suspend and resume PM ops for tegra SDHCI.
> 
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
>  drivers/mmc/host/sdhci-tegra.c | 45 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index eafaaefab4a6..68263ea4a93e 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -1611,11 +1611,54 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int sdhci_tegra_suspend(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	int ret;
> +
> +	if (host->mmc->caps2 & MMC_CAP2_CQE) {
> +		ret = cqhci_suspend(host->mmc);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = sdhci_suspend_host(host);
> +	if (ret)
> +		return ret;
> +
> +	clk_disable_unprepare(pltfm_host->clk);
> +	return 0;
> +}
> +
> +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;
> +
> +	clk_prepare_enable(pltfm_host->clk);

You need to check this for errors here.

> +
> +	ret = sdhci_resume_host(host);
> +	if (ret)
> +		return ret;

And clk_disable_unprepare() in case of failure.

> +
> +	if (host->mmc->caps2 & MMC_CAP2_CQE)
> +		return cqhci_resume(host->mmc);

Same here. Also make sure to sdhci_suspend_host() if cqhci_resume()
fails. It's probably best to have a standard error cleanup path for
this.

Thierry
Sowjanya Komatineni April 2, 2019, 4:41 p.m. UTC | #2
> On Mon, Apr 01, 2019 at 10:27:33PM -0700, Sowjanya Komatineni wrote:
> > This patch adds suspend and resume PM ops for tegra SDHCI.
> > 
> > Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> > ---
> >  drivers/mmc/host/sdhci-tegra.c | 45 
> > +++++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 44 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-tegra.c 
> > b/drivers/mmc/host/sdhci-tegra.c index eafaaefab4a6..68263ea4a93e 
> > 100644
> > --- a/drivers/mmc/host/sdhci-tegra.c
> > +++ b/drivers/mmc/host/sdhci-tegra.c
> > @@ -1611,11 +1611,54 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
> >  	return 0;
> >  }
> >  
> > +#ifdef CONFIG_PM_SLEEP
> > +static int sdhci_tegra_suspend(struct device *dev) {
> > +	struct sdhci_host *host = dev_get_drvdata(dev);
> > +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +	int ret;
> > +
> > +	if (host->mmc->caps2 & MMC_CAP2_CQE) {
> > +		ret = cqhci_suspend(host->mmc);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	ret = sdhci_suspend_host(host);
> > +	if (ret)
> > +		return ret;
> > +
> > +	clk_disable_unprepare(pltfm_host->clk);
> > +	return 0;
> > +}
> > +
> > +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;
> > +
> > +	clk_prepare_enable(pltfm_host->clk);
>
> You need to check this for errors here.
>
> > +
> > +	ret = sdhci_resume_host(host);
> > +	if (ret)
> > +		return ret;
>
> And clk_disable_unprepare() in case of failure.
>
> > +
> > +	if (host->mmc->caps2 & MMC_CAP2_CQE)
> > +		return cqhci_resume(host->mmc);
>
> Same here. Also make sure to sdhci_suspend_host() if cqhci_resume() fails. It's probably best to have a standard error cleanup path for this.
>
> Thierry

Thanks Thierry. Will add error check and cleanup for clock and sdhci_resume_host.
Regarding, cqhci_resume always returns 0. Infact, it does nothing as resume happens on first cqhci_request.
Since helper functions exists in cqhci driver, was using it for explicit resume call.
Thierry Reding April 2, 2019, 4:48 p.m. UTC | #3
On Tue, Apr 02, 2019 at 04:41:18PM +0000, Sowjanya Komatineni wrote:
> > On Mon, Apr 01, 2019 at 10:27:33PM -0700, Sowjanya Komatineni wrote:
> > > This patch adds suspend and resume PM ops for tegra SDHCI.
> > > 
> > > Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> > > ---
> > >  drivers/mmc/host/sdhci-tegra.c | 45 
> > > +++++++++++++++++++++++++++++++++++++++++-
> > >  1 file changed, 44 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/mmc/host/sdhci-tegra.c 
> > > b/drivers/mmc/host/sdhci-tegra.c index eafaaefab4a6..68263ea4a93e 
> > > 100644
> > > --- a/drivers/mmc/host/sdhci-tegra.c
> > > +++ b/drivers/mmc/host/sdhci-tegra.c
> > > @@ -1611,11 +1611,54 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
> > >  	return 0;
> > >  }
> > >  
> > > +#ifdef CONFIG_PM_SLEEP
> > > +static int sdhci_tegra_suspend(struct device *dev) {
> > > +	struct sdhci_host *host = dev_get_drvdata(dev);
> > > +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > > +	int ret;
> > > +
> > > +	if (host->mmc->caps2 & MMC_CAP2_CQE) {
> > > +		ret = cqhci_suspend(host->mmc);
> > > +		if (ret)
> > > +			return ret;
> > > +	}
> > > +
> > > +	ret = sdhci_suspend_host(host);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	clk_disable_unprepare(pltfm_host->clk);
> > > +	return 0;
> > > +}
> > > +
> > > +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;
> > > +
> > > +	clk_prepare_enable(pltfm_host->clk);
> >
> > You need to check this for errors here.
> >
> > > +
> > > +	ret = sdhci_resume_host(host);
> > > +	if (ret)
> > > +		return ret;
> >
> > And clk_disable_unprepare() in case of failure.
> >
> > > +
> > > +	if (host->mmc->caps2 & MMC_CAP2_CQE)
> > > +		return cqhci_resume(host->mmc);
> >
> > Same here. Also make sure to sdhci_suspend_host() if cqhci_resume() fails. It's probably best to have a standard error cleanup path for this.
> >
> > Thierry
> 
> Thanks Thierry. Will add error check and cleanup for clock and sdhci_resume_host.
> Regarding, cqhci_resume always returns 0. Infact, it does nothing as resume happens on first cqhci_request.
> Since helper functions exists in cqhci driver, was using it for explicit resume call.

Yeah, I think it's good to use it. And I think it's also the safest
option to handle errors from it properly because somebody may eventually
add code to it that can fail. If we properly handle errors we'll be
prepared for when that happens.

Thierry
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index eafaaefab4a6..68263ea4a93e 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -1611,11 +1611,54 @@  static int sdhci_tegra_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int sdhci_tegra_suspend(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	int ret;
+
+	if (host->mmc->caps2 & MMC_CAP2_CQE) {
+		ret = cqhci_suspend(host->mmc);
+		if (ret)
+			return ret;
+	}
+
+	ret = sdhci_suspend_host(host);
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(pltfm_host->clk);
+	return 0;
+}
+
+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;
+
+	clk_prepare_enable(pltfm_host->clk);
+
+	ret = sdhci_resume_host(host);
+	if (ret)
+		return ret;
+
+	if (host->mmc->caps2 & MMC_CAP2_CQE)
+		return cqhci_resume(host->mmc);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(sdhci_tegra_dev_pm_ops, sdhci_tegra_suspend,
+			 sdhci_tegra_resume);
+
 static struct platform_driver sdhci_tegra_driver = {
 	.driver		= {
 		.name	= "sdhci-tegra",
 		.of_match_table = sdhci_tegra_dt_match,
-		.pm	= &sdhci_pltfm_pmops,
+		.pm	= &sdhci_tegra_dev_pm_ops,
 	},
 	.probe		= sdhci_tegra_probe,
 	.remove		= sdhci_tegra_remove,