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 --- 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); };