Hi Ulf, On 2023/2/14 7:45, Ulf Hansson wrote:
On Thu, 2 Feb 2023 at 01:35, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:This patch adds runtime PM support. Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- Changes in v2: None drivers/mmc/host/sdhci-of-dwcmshc.c | 51 ++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c index 46b1ce7..fc917ed 100644 --- a/drivers/mmc/host/sdhci-of-dwcmshc.c +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c @@ -15,6 +15,7 @@ #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/pm_runtime.h> #include <linux/reset.h> #include <linux/sizes.h> @@ -551,6 +552,13 @@ static int dwcmshc_probe(struct platform_device *pdev) if (err) goto err_setup_host; + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, 50); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_put_autosuspend(&pdev->dev); + return 0; err_setup_host: @@ -580,6 +588,11 @@ static int dwcmshc_remove(struct platform_device *pdev) if (rk_priv) clk_bulk_disable_unprepare(RK35xx_MAX_CLKS, rk_priv->rockchip_clks); + + pm_runtime_get_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); + sdhci_pltfm_free(pdev); return 0; @@ -638,7 +651,43 @@ static int dwcmshc_resume(struct device *dev) } #endif -static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend, dwcmshc_resume); +#ifdef CONFIG_PM +static int dwcmshc_runtime_suspend(struct device *dev) +{ + struct sdhci_host *host = dev_get_drvdata(dev); + u16 data; + int ret; + + ret = sdhci_runtime_suspend_host(host); + if (ret) + return ret; + + data = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + data &= ~SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, data, SDHCI_CLOCK_CONTROL); + + return 0; +} + +static int dwcmshc_runtime_resume(struct device *dev) +{ + struct sdhci_host *host = dev_get_drvdata(dev); + u16 data; + + data = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + data |= SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, data, SDHCI_CLOCK_CONTROL); + + return sdhci_runtime_resume_host(host, 0); +} +#endif + +static const struct dev_pm_ops dwcmshc_pmops = { + SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, + dwcmshc_resume)I have looked at dwcmshc_suspend(), which calls sdhci_suspend_host(). As sdhci_suspend_host() will write to internal registers of the IP block, it's recommended to make sure the device's runtime resumed before doing that call. So that needs to be added along with $subject patch.
Yep, let me add a check here.
There is also another option that may better for you, which is to use the pm_runtime_force_suspend|resume() helpers. There should be plenty of references to look at, but don't hesitate to ask around that, if you need some more help to get that working.
If I understand correctly, pm_runtime_force_suspend|resume() helpers would use runtime PM ops for suspend/resume routine. In this case, the main issue is the handling of clock is quite different. In suspend we need to gate all clocks but in rpm case, it shouldn't.
+ SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend, + dwcmshc_runtime_resume, NULL) +}; static struct platform_driver sdhci_dwcmshc_driver = { .driver = {Kind regards Uffe
