On Sat, 20 Nov 2021 at 12:23, Kyle Copperfield <kmcopper@xxxxxxxxxxxxx> wrote: > > Add runtime power management support in Arasan SDHCI driver. > > This patch is largely based on the original Arasan PM patch from > https://lore.kernel.org/linux-mmc/1537283046-13985-1-git-send-email-manish.narani@xxxxxxxxxx/ > that was left abandoned since 2018 for an unknown reason. > > Changes made to the original patch include reducing the runtime > suspend timeout to 50 ms and reusing the runtime PM configuration > found in sdhci-of-at91 driver. > > Power consumption is measurably reduced on the Pinebook Pro and > PinePhone Pro, on which the patch was tested. More precisely, > a reduction of about 200 mW was measured on the latter. > > Originally-by: Manish Narani <manish.narani@xxxxxxxxxx> > Reviewed-by: Dragan Simic <dragan.simic@xxxxxxxxx> > Tested-by: Ondrej Jirman <megous@xxxxxxxxxx> > Signed-off-by: Kyle Copperfield <kmcopper@xxxxxxxxxxxxx> > --- > drivers/mmc/host/sdhci-of-arasan.c | 88 +++++++++++++++++++++++++++++- > 1 file changed, 86 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c > index 737e2bfdedc2..63095d91a672 100644 > --- a/drivers/mmc/host/sdhci-of-arasan.c > +++ b/drivers/mmc/host/sdhci-of-arasan.c > @@ -19,6 +19,7 @@ > #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> > @@ -27,6 +28,7 @@ > #include "cqhci.h" > #include "sdhci-pltfm.h" > > +#define SDHCI_ARASAN_AUTOSUSPEND_DELAY 50 /* ms */ > #define SDHCI_ARASAN_VENDOR_REGISTER 0x78 > > #define SDHCI_ARASAN_ITAPDLY_REGISTER 0xF0F8 > @@ -456,6 +458,70 @@ static const struct sdhci_pltfm_data sdhci_arasan_cqe_pdata = { > SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN, > }; > > +static int __maybe_unused 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; > + > + if (sdhci_arasan->has_cqe) { > + ret = cqhci_suspend(host->mmc); > + if (ret) > + return 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); These should be clk_disable_unprepare() - and the corresponding clk_enable() below, needs to be converted to clk_prepare_enable(). Moreover, I am wondering about why the phy is to be turned off with phy_power_off() during system suspend, but not during runtime suspend? When is it safe to turn off the phy? > + > + return 0; > +} > + > +static int __maybe_unused 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: %d\n", ret); > + return ret; > + } > + > + ret = clk_enable(pltfm_host->clk); > + if (ret) { > + dev_err(dev, "Cannot enable SD clock: %d\n", ret); > + goto err_clk_ahb; > + } > + > + ret = sdhci_runtime_resume_host(host, 0); > + if (ret) > + goto err_clk_disable; > + > + if (sdhci_arasan->has_cqe) > + return cqhci_resume(host->mmc); > + > + return 0; > + > +err_clk_disable: > + clk_disable(pltfm_host->clk); > +err_clk_ahb: > + clk_disable(sdhci_arasan->clk_ahb); > + > + return ret; > +} > + > #ifdef CONFIG_PM_SLEEP > /** > * sdhci_arasan_suspend - Suspend method for the driver > @@ -552,8 +618,10 @@ 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) In sdhci_arasan_suspend() we assume that the clocks, etc are turned on. This may not be the case anymore, as sdhci_arasan_runtime_suspend() may already have done that. There are a couple of options to deal with that, like using pm_runtime_force_suspend|resume(). But then don't forget that you may need to manage system wakeups, if that is supported. > + SET_RUNTIME_PM_OPS(sdhci_arasan_runtime_suspend, > + sdhci_arasan_runtime_resume, NULL) }; > > /** > * sdhci_arasan_sdcardclk_recalc_rate - Return the card clock rate > @@ -1681,13 +1749,25 @@ static int sdhci_arasan_probe(struct platform_device *pdev) > host->mmc->caps2 |= MMC_CAP2_CQE_DCMD; > } > > + pm_runtime_get_noresume(&pdev->dev); > + pm_runtime_set_active(&pdev->dev); > + pm_runtime_enable(&pdev->dev); > + pm_runtime_set_autosuspend_delay(&pdev->dev, SDHCI_ARASAN_AUTOSUSPEND_DELAY); > + pm_runtime_use_autosuspend(&pdev->dev); > + > ret = sdhci_arasan_add_host(sdhci_arasan); > if (ret) > goto err_add_host; > > + pm_runtime_put_autosuspend(&pdev->dev); > + > return 0; > > err_add_host: > + pm_runtime_disable(&pdev->dev); > + pm_runtime_set_suspended(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); > + > if (!IS_ERR(sdhci_arasan->phy)) > phy_exit(sdhci_arasan->phy); > unreg_clk: > @@ -1715,6 +1795,10 @@ static int sdhci_arasan_remove(struct platform_device *pdev) > phy_exit(sdhci_arasan->phy); > } > > + pm_runtime_get_sync(&pdev->dev); > + pm_runtime_disable(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); > + > sdhci_arasan_unregister_sdclk(&pdev->dev); > > ret = sdhci_pltfm_unregister(pdev); Kind regards Uffe
