Commit 7f98a905 authored by Rajagopal Venkat's avatar Rajagopal Venkat Committed by Rafael J. Wysocki
Browse files

PM / devfreq: Add current freq callback in device profile 



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: default avatarRajagopal Venkat <rajagopal.venkat@linaro.org>
Acked-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 206c30cf

Documentation/ABI/testing/sysfs-class-devfreq

+10 −1
Original line number Diff line number Diff line
@@ -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

drivers/devfreq/devfreq.c

+14 −0
Original line number Diff line number Diff line
@@ -463,6 +463,19 @@ 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);

}
@@ -563,6 +576,7 @@ 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),

include/linux/devfreq.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

};

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