[v4,2/3] devfreq: Add suspend and resume apis

Add devfreq suspend/resume apis for devfreq users. This patch
supports suspend and resume of devfreq load monitoring, required
for devices which can idle.

Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---
 drivers/devfreq/devfreq.c                 | 28 ++++++++++++++++++++++++++++
 drivers/devfreq/governor.h                |  2 ++
 drivers/devfreq/governor_simpleondemand.c |  9 +++++++++
 include/linux/devfreq.h                   | 12 ++++++++++++
 4 files changed, 51 insertions(+)

On Thursday 04 of October 2012 14:58:33 Rajagopal Venkat wrote:
> Add devfreq suspend/resume apis for devfreq users. This patch
> supports suspend and resume of devfreq load monitoring, required
> for devices which can idle.
> 
> Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Well, I wonder if this may be tied in to the runtime PM framework, so that,
for example, pm_runtime_suspend() will automatically suspend devfreq on
success (and the runtime resume of the device will resume devfreq)?

Rafael


> ---
>  drivers/devfreq/devfreq.c                 | 28 ++++++++++++++++++++++++++++
>  drivers/devfreq/governor.h                |  2 ++
>  drivers/devfreq/governor_simpleondemand.c |  9 +++++++++
>  include/linux/devfreq.h                   | 12 ++++++++++++
>  4 files changed, 51 insertions(+)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 41a4099..63e075e 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -428,6 +428,34 @@ int devfreq_remove_device(struct devfreq *devfreq)
>  }
>  EXPORT_SYMBOL(devfreq_remove_device);
>  
> +/**
> + * devfreq_suspend_device() - Suspend devfreq of a device.
> + * @devfreq	the devfreq instance to be suspended
> + */
> +int devfreq_suspend_device(struct devfreq *devfreq)
> +{
> +	if (!devfreq)
> +		return -EINVAL;
> +
> +	return devfreq->governor->event_handler(devfreq,
> +				DEVFREQ_GOV_SUSPEND, NULL);
> +}
> +EXPORT_SYMBOL(devfreq_suspend_device);
> +
> +/**
> + * devfreq_resume_device() - Resume devfreq of a device.
> + * @devfreq	the devfreq instance to be resumed
> + */
> +int devfreq_resume_device(struct devfreq *devfreq)
> +{
> +	if (!devfreq)
> +		return -EINVAL;
> +
> +	return devfreq->governor->event_handler(devfreq,
> +				DEVFREQ_GOV_RESUME, NULL);
> +}
> +EXPORT_SYMBOL(devfreq_resume_device);
> +
>  static ssize_t show_governor(struct device *dev,
>  			     struct device_attribute *attr, char *buf)
>  {
> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
> index bb3aff3..26432ac 100644
> --- a/drivers/devfreq/governor.h
> +++ b/drivers/devfreq/governor.h
> @@ -22,6 +22,8 @@
>  #define DEVFREQ_GOV_START			0x1
>  #define DEVFREQ_GOV_STOP			0x2
>  #define DEVFREQ_GOV_INTERVAL			0x3
> +#define DEVFREQ_GOV_SUSPEND			0x4
> +#define DEVFREQ_GOV_RESUME			0x5
>  
>  /* Caution: devfreq->lock must be locked before calling update_devfreq */
>  extern int update_devfreq(struct devfreq *devfreq);
> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
> index cf94218..a8ba78c 100644
> --- a/drivers/devfreq/governor_simpleondemand.c
> +++ b/drivers/devfreq/governor_simpleondemand.c
> @@ -104,6 +104,15 @@ int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
>  	case DEVFREQ_GOV_INTERVAL:
>  		devfreq_interval_update(devfreq, (unsigned int *)data);
>  		break;
> +
> +	case DEVFREQ_GOV_SUSPEND:
> +		devfreq_monitor_suspend(devfreq);
> +		break;
> +
> +	case DEVFREQ_GOV_RESUME:
> +		devfreq_monitor_resume(devfreq);
> +		break;
> +
>  	default:
>  		break;
>  	}
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index 9cdffde..ee243a3 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -158,6 +158,8 @@ extern struct devfreq *devfreq_add_device(struct device *dev,
>  				  const struct devfreq_governor *governor,
>  				  void *data);
>  extern int devfreq_remove_device(struct devfreq *devfreq);
> +extern int devfreq_suspend_device(struct devfreq *devfreq);
> +extern int devfreq_resume_device(struct devfreq *devfreq);
>  
>  /* Helper functions for devfreq user device driver with OPP. */
>  extern struct opp *devfreq_recommended_opp(struct device *dev,
> @@ -211,6 +213,16 @@ static int devfreq_remove_device(struct devfreq *devfreq)
>  	return 0;
>  }
>  
> +static int devfreq_suspend_device(struct devfreq *devfreq)
> +{
> +	return 0;
> +}
> +
> +static int devfreq_resume_device(struct devfreq *devfreq)
> +{
> +	return 0;
> +}
> +
>  static struct opp *devfreq_recommended_opp(struct device *dev,
>  					   unsigned long *freq, u32 flags)
>  {
>

On 8 October 2012 03:31, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Thursday 04 of October 2012 14:58:33 Rajagopal Venkat wrote:
>> Add devfreq suspend/resume apis for devfreq users. This patch
>> supports suspend and resume of devfreq load monitoring, required
>> for devices which can idle.
>>
>> Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
>> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
>
> Well, I wonder if this may be tied in to the runtime PM framework, so that,
> for example, pm_runtime_suspend() will automatically suspend devfreq on
> success (and the runtime resume of the device will resume devfreq)?

That's a good idea. If you agree, we can handle this as separate patch on
top this patchset.

>
> Rafael
>
>
>> ---
>>  drivers/devfreq/devfreq.c                 | 28 ++++++++++++++++++++++++++++
>>  drivers/devfreq/governor.h                |  2 ++
>>  drivers/devfreq/governor_simpleondemand.c |  9 +++++++++
>>  include/linux/devfreq.h                   | 12 ++++++++++++
>>  4 files changed, 51 insertions(+)
>>
>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>> index 41a4099..63e075e 100644
>> --- a/drivers/devfreq/devfreq.c
>> +++ b/drivers/devfreq/devfreq.c
>> @@ -428,6 +428,34 @@ int devfreq_remove_device(struct devfreq *devfreq)
>>  }
>>  EXPORT_SYMBOL(devfreq_remove_device);
>>
>> +/**
>> + * devfreq_suspend_device() - Suspend devfreq of a device.
>> + * @devfreq  the devfreq instance to be suspended
>> + */
>> +int devfreq_suspend_device(struct devfreq *devfreq)
>> +{
>> +     if (!devfreq)
>> +             return -EINVAL;
>> +
>> +     return devfreq->governor->event_handler(devfreq,
>> +                             DEVFREQ_GOV_SUSPEND, NULL);
>> +}
>> +EXPORT_SYMBOL(devfreq_suspend_device);
>> +
>> +/**
>> + * devfreq_resume_device() - Resume devfreq of a device.
>> + * @devfreq  the devfreq instance to be resumed
>> + */
>> +int devfreq_resume_device(struct devfreq *devfreq)
>> +{
>> +     if (!devfreq)
>> +             return -EINVAL;
>> +
>> +     return devfreq->governor->event_handler(devfreq,
>> +                             DEVFREQ_GOV_RESUME, NULL);
>> +}
>> +EXPORT_SYMBOL(devfreq_resume_device);
>> +
>>  static ssize_t show_governor(struct device *dev,
>>                            struct device_attribute *attr, char *buf)
>>  {
>> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
>> index bb3aff3..26432ac 100644
>> --- a/drivers/devfreq/governor.h
>> +++ b/drivers/devfreq/governor.h
>> @@ -22,6 +22,8 @@
>>  #define DEVFREQ_GOV_START                    0x1
>>  #define DEVFREQ_GOV_STOP                     0x2
>>  #define DEVFREQ_GOV_INTERVAL                 0x3
>> +#define DEVFREQ_GOV_SUSPEND                  0x4
>> +#define DEVFREQ_GOV_RESUME                   0x5
>>
>>  /* Caution: devfreq->lock must be locked before calling update_devfreq */
>>  extern int update_devfreq(struct devfreq *devfreq);
>> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
>> index cf94218..a8ba78c 100644
>> --- a/drivers/devfreq/governor_simpleondemand.c
>> +++ b/drivers/devfreq/governor_simpleondemand.c
>> @@ -104,6 +104,15 @@ int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
>>       case DEVFREQ_GOV_INTERVAL:
>>               devfreq_interval_update(devfreq, (unsigned int *)data);
>>               break;
>> +
>> +     case DEVFREQ_GOV_SUSPEND:
>> +             devfreq_monitor_suspend(devfreq);
>> +             break;
>> +
>> +     case DEVFREQ_GOV_RESUME:
>> +             devfreq_monitor_resume(devfreq);
>> +             break;
>> +
>>       default:
>>               break;
>>       }
>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>> index 9cdffde..ee243a3 100644
>> --- a/include/linux/devfreq.h
>> +++ b/include/linux/devfreq.h
>> @@ -158,6 +158,8 @@ extern struct devfreq *devfreq_add_device(struct device *dev,
>>                                 const struct devfreq_governor *governor,
>>                                 void *data);
>>  extern int devfreq_remove_device(struct devfreq *devfreq);
>> +extern int devfreq_suspend_device(struct devfreq *devfreq);
>> +extern int devfreq_resume_device(struct devfreq *devfreq);
>>
>>  /* Helper functions for devfreq user device driver with OPP. */
>>  extern struct opp *devfreq_recommended_opp(struct device *dev,
>> @@ -211,6 +213,16 @@ static int devfreq_remove_device(struct devfreq *devfreq)
>>       return 0;
>>  }
>>
>> +static int devfreq_suspend_device(struct devfreq *devfreq)
>> +{
>> +     return 0;
>> +}
>> +
>> +static int devfreq_resume_device(struct devfreq *devfreq)
>> +{
>> +     return 0;
>> +}
>> +
>>  static struct opp *devfreq_recommended_opp(struct device *dev,
>>                                          unsigned long *freq, u32 flags)
>>  {
>>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.