Re: [PATCH v4] mmc: sdhci-msm: Add pm_runtime and system PM support

[Pramod Gurav <pramod.gurav@linaro.org>]

Hi Ritesh,

On 20 October 2016 at 20:20, Ritesh Harjani <riteshh@codeaurora.org> wrote:
> Hi Pramod,
>
> Thanks for this patch. Few minor comments.
>
> I have tested your patch on db410c and 8996 based internal platform and it
> works fine.
Thanks for the review and testing.
>
>
>
> On 10/18/2016 3:46 PM, Pramod Gurav wrote:
>>
>> Provides runtime PM callbacks to enable and disable clock resources
>> when idle. Also support system PM callbacks to be called during system
>> suspend and resume.
>>
>> Signed-off-by: Pramod Gurav <pramod.gurav@linaro.org>
>> ---
>>
>> Tested on DB410C.
>>
>> Changes in v4:
>> - Remove calls to sdhci_runtime_resume_host/sdhci_runtime_suspend_host
>>   from runtime callbacks as sdhc msm controller is capable of restoring
>>   it's register values after clocks are disabled and re-enabled.
>>
>> Changes in v3:
>> - Added CONFIG_PM around runtime pm function.
>> - Replaced msm suspend/resume with generic function directly
>> - Use SET_SYSTEM_SLEEP_PM_OPS instead of late version
>>
>> Changes in v2:
>> - Moved pm_rutime enabling before adding host
>> - Handled pm_rutime in remove
>> - Changed runtime handling with reference from sdhci-of-at91.c
>>
>>  drivers/mmc/host/sdhci-msm.c | 66
>> +++++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 65 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 8ef44a2a..33ec809 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -18,6 +18,7 @@
>>  #include <linux/of_device.h>
>>  #include <linux/delay.h>
>>  #include <linux/mmc/mmc.h>
>> +#include <linux/pm_runtime.h>
>>  #include <linux/slab.h>
>>
>>  #include "sdhci-pltfm.h"
>> @@ -658,12 +659,26 @@ static int sdhci_msm_probe(struct platform_device
>> *pdev)
>>                 goto clk_disable;
>>         }
>>
>> +       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);
>
> Use a macro MSM_MMC_AUTOSUSPEND_DELAY_MS instead of using 50 directly here.

Will add.
>
>> +       pm_runtime_use_autosuspend(&pdev->dev);
>> +
>>         ret = sdhci_add_host(host);
>>         if (ret)
>> -               goto clk_disable;
>> +               goto pm_runtime_disable;
>> +
>> +       platform_set_drvdata(pdev, host);
>
> No need to set platform_set_drvdata here. sdhci_pltfm_init will do it
> anyways.
Good to know this. Will do away with this.
>
>> +
>
> pm_runtime_mark_last_busy(&pdev->dev) can be added here.
Yeah. Agree.
>
>> +       pm_runtime_put_autosuspend(&pdev->dev);
>>
>>         return 0;
>>
>> +pm_runtime_disable:
>> +       pm_runtime_disable(&pdev->dev);
>> +       pm_runtime_set_suspended(&pdev->dev);
>> +       pm_runtime_put_noidle(&pdev->dev);
>>  clk_disable:
>>         clk_disable_unprepare(msm_host->clk);
>>  pclk_disable:
>> @@ -685,6 +700,11 @@ static int sdhci_msm_remove(struct platform_device
>> *pdev)
>>                     0xffffffff);
>>
>>         sdhci_remove_host(host, dead);
>> +
>> +       pm_runtime_get_sync(&pdev->dev);
>> +       pm_runtime_disable(&pdev->dev);
>> +       pm_runtime_put_noidle(&pdev->dev);
>> +
>>         clk_disable_unprepare(msm_host->clk);
>>         clk_disable_unprepare(msm_host->pclk);
>>         if (!IS_ERR(msm_host->bus_clk))
>> @@ -693,12 +713,56 @@ static int sdhci_msm_remove(struct platform_device
>> *pdev)
>>         return 0;
>>  }
>>
>> +#ifdef CONFIG_PM
>> +static int sdhci_msm_runtime_suspend(struct device *dev)
>> +{
>> +       struct sdhci_host *host = dev_get_drvdata(dev);
>> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +
>> +       clk_disable_unprepare(msm_host->clk);
>> +       clk_disable_unprepare(msm_host->pclk);
>> +
>> +       return 0;
>> +}
>> +
>> +static int sdhci_msm_runtime_resume(struct device *dev)
>> +{
>> +       struct sdhci_host *host = dev_get_drvdata(dev);
>> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +       int ret;
>> +
>> +       ret = clk_prepare_enable(msm_host->clk);
>> +       if (ret) {
>> +               dev_err(dev, "clk_enable failed: %d\n", ret);
>
> dev_err(dev, "clk enable failed for core_clk: %d\n", ret);
>
>> +               return ret;
>> +       }
>> +       ret = clk_prepare_enable(msm_host->pclk);
>> +       if (ret) {
>> +               dev_err(dev, "clk_enable failed: %d\n", ret);
>
> dev_err(dev, "clk enable failed for iface_clk: %d\n", ret);
>

Yes. will do these changes. Thanks for comments. :)

>> +               clk_disable_unprepare(msm_host->clk);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops sdhci_msm_pm_ops = {
>> +       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> +                                       pm_runtime_force_resume)
>> +       SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
>> sdhci_msm_runtime_resume,
>> +                               NULL)
>> +};
>> +
>>  static struct platform_driver sdhci_msm_driver = {
>>         .probe = sdhci_msm_probe,
>>         .remove = sdhci_msm_remove,
>>         .driver = {
>>                    .name = "sdhci_msm",
>>                    .of_match_table = sdhci_msm_dt_match,
>> +                  .pm = &sdhci_msm_pm_ops,
>>         },
>>  };
>>
>>
>
> --
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> a Linux Foundation Collaborative Project