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* Re: [PATCH v2 3/3] devfreq: Add current freq callback in device profile
@ 2012-09-17 10:34 MyungJoo Ham
  2012-09-17 20:04 ` Rafael J. Wysocki
  0 siblings, 1 reply; 3+ messages in thread
From: MyungJoo Ham @ 2012-09-17 10:34 UTC (permalink / raw)
  To: Rajagopal Venkat, mturquette@linaro.org, 박경민,
	rjw@sisk.pl
  Cc: patches@linaro.org, linaro-dev@lists.linaro.org,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org

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> From: Rajagopal Venkat <rajagopal.venkat@linaro.org>
> 
> Devfreq returns governor predicted frequency as current frequency
> via sysfs interface. But device may not support all frequencies
> that governor predicts. So add a callback in device profile to get
> current freq from driver. Also add a new sysfs node to expose
> governor predicted next target frequency.
> 
> Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

> ---
>  Documentation/ABI/testing/sysfs-class-devfreq | 11 ++++++++++-
>  drivers/devfreq/devfreq.c                     | 14 ++++++++++++++
>  include/linux/devfreq.h                       |  3 +++
>  3 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq
> index 89283b1..e6cf08e 100644
> --- a/Documentation/ABI/testing/sysfs-class-devfreq
> +++ b/Documentation/ABI/testing/sysfs-class-devfreq
> @@ -19,7 +19,16 @@ Date:		September 2011
>  Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
>  Description:
>  		The /sys/class/devfreq/.../cur_freq shows the current
> -		frequency of the corresponding devfreq object.
> +		frequency of the corresponding devfreq object. Same as
> +		target_freq when get_cur_freq() is not implemented by
> +		devfreq driver.
> +
> +What:		/sys/class/devfreq/.../target_freq
> +Date:		September 2012
> +Contact:	Rajagopal Venkat <rajagopal.venkat@linaro.org>
> +Description:
> +		The /sys/class/devfreq/.../target_freq shows the next governor
> +		predicted target frequency of the corresponding devfreq object.
>  
>  What:		/sys/class/devfreq/.../polling_interval
>  Date:		September 2011
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 309c46e..049e273 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -401,6 +401,19 @@ static ssize_t show_governor(struct device *dev,
>  static ssize_t show_freq(struct device *dev,
>  			 struct device_attribute *attr, char *buf)
>  {
> +	unsigned long freq;
> +	struct devfreq *devfreq = to_devfreq(dev);
> +
> +	if (devfreq->profile->get_cur_freq &&
> +		!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
> +			return sprintf(buf, "%lu\n", freq);
> +
> +	return sprintf(buf, "%lu\n", devfreq->previous_freq);
> +}
> +
> +static ssize_t show_target_freq(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
>  	return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
>  }
>  
> @@ -504,6 +517,7 @@ static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr,
>  static struct device_attribute devfreq_attrs[] = {
>  	__ATTR(governor, S_IRUGO, show_governor, NULL),
>  	__ATTR(cur_freq, S_IRUGO, show_freq, NULL),
> +	__ATTR(target_freq, S_IRUGO, show_target_freq, NULL),
>  	__ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval,
>  	       store_polling_interval),
>  	__ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq),
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index 7c7e179..d12ed41 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -66,6 +66,8 @@ struct devfreq_dev_status {
>   *			explained above with "DEVFREQ_FLAG_*" macros.
>   * @get_dev_status	The device should provide the current performance
>   *			status to devfreq, which is used by governors.
> + * @get_cur_freq	The device should provide the current frequency
> + *			at which it is operating.
>   * @exit		An optional callback that is called when devfreq
>   *			is removing the devfreq object due to error or
>   *			from devfreq_remove_device() call. If the user
> @@ -79,6 +81,7 @@ struct devfreq_dev_profile {
>  	int (*target)(struct device *dev, unsigned long *freq, u32 flags);
>  	int (*get_dev_status)(struct device *dev,
>  			      struct devfreq_dev_status *stat);
> +	int (*get_cur_freq)(struct device *dev, unsigned long *freq);
>  	void (*exit)(struct device *dev);
>  };
>  
> -- 
> 1.7.11.3
> 
> 
> 
> 
>        
>   
>          
> 
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^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH v2 0/3] devfreq: Add support for devices which can idle
@ 2012-09-13 13:55 Rajagopal Venkat
  2012-09-13 13:55 ` [PATCH v2 3/3] devfreq: Add current freq callback in device profile Rajagopal Venkat
  0 siblings, 1 reply; 3+ messages in thread
From: Rajagopal Venkat @ 2012-09-13 13:55 UTC (permalink / raw)
  To: mturquette, myungjoo.ham, kyungmin.park, rjw
  Cc: patches, linaro-dev, linux-pm, linux-kernel, Rajagopal Venkat

From: Rajagopal Venkat <rajagopal.venkat@linaro.org>

This patchset updates devfreq core to add support for devices
which can idle. When device idleness is detected perhaps
through runtime-pm, need some mechanism to suspend devfreq
load monitoring and resume when device is back online.

patch 1 introduce core design changes - per device work, decouple
delayed work from core and event based interaction.
patch 2 add devfreq suspend and resume apis.
patch 3 add new sysfs attribute for governor predicted next target
frequency and callback for current device frequency.

The existing devfreq apis are kept intact. Two new apis
devfreq_suspend_device() and devfreq_resume_device() are
added to support suspend/resume of device devfreq.

Changes since v1:
- revised locking mechanism
- added kerneldoc comments for load monitoring helper functions
- Fixed minor review comments

--
Rajagopal Venkat (3):
  devfreq: Core updates to support devices which can idle
  devfreq: Add suspend and resume apis
  devfreq: Add current freq callback in device profile

 Documentation/ABI/testing/sysfs-class-devfreq |  15 +-
 drivers/devfreq/devfreq.c                     | 413 +++++++++++---------------
 drivers/devfreq/governor.h                    |  11 +
 drivers/devfreq/governor_performance.c        |  16 +-
 drivers/devfreq/governor_powersave.c          |  16 +-
 drivers/devfreq/governor_simpleondemand.c     |  40 +++
 drivers/devfreq/governor_userspace.c          |  23 +-
 include/linux/devfreq.h                       |  46 ++-
 8 files changed, 291 insertions(+), 289 deletions(-)

-- 
1.7.11.3


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-09-17 19:57 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2012-09-17 10:34 [PATCH v2 3/3] devfreq: Add current freq callback in device profile MyungJoo Ham
2012-09-17 20:04 ` Rafael J. Wysocki
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2012-09-13 13:55 [PATCH v2 0/3] devfreq: Add support for devices which can idle Rajagopal Venkat
2012-09-13 13:55 ` [PATCH v2 3/3] devfreq: Add current freq callback in device profile Rajagopal Venkat

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