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Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-devfreq')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 84 |
1 files changed, 59 insertions, 25 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 01196e19afca..1e7e0bb4c14e 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -7,6 +7,13 @@ Description: The name of devfreq object denoted as ... is same as the name of device using devfreq. +What: /sys/class/devfreq/.../name +Date: November 2019 +Contact: Chanwoo Choi <cw00.choi@samsung.com> +Description: + The /sys/class/devfreq/.../name shows the name of device + of the corresponding devfreq object. + What: /sys/class/devfreq/.../governor Date: September 2011 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> @@ -30,38 +37,23 @@ 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 -Contact: MyungJoo Ham <myungjoo.ham@samsung.com> -Description: - The /sys/class/devfreq/.../polling_interval shows and sets - the requested polling interval of the corresponding devfreq - object. The values are represented in ms. If the value is - less than 1 jiffy, it is considered to be 0, which means - no polling. This value is meaningless if the governor is - not polling; thus. If the governor is not using - devfreq-provided central polling - (/sys/class/devfreq/.../central_polling is 0), this value - may be useless. - What: /sys/class/devfreq/.../trans_stat Date: October 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Description: - This ABI shows the statistics of devfreq behavior on a - specific device. It shows the time spent in each state and - the number of transitions between states. + This ABI shows or clears the statistics of devfreq behavior + on a specific device. It shows the time spent in each state + and the number of transitions between states. In order to activate this ABI, the devfreq target device driver should provide the list of available frequencies - with its profile. + with its profile. If need to reset the statistics of devfreq + behavior on a specific device, enter 0(zero) to 'trans_stat' + as following:: -What: /sys/class/devfreq/.../userspace/set_freq -Date: September 2011 -Contact: MyungJoo Ham <myungjoo.ham@samsung.com> -Description: - The /sys/class/devfreq/.../userspace/set_freq shows and - sets the requested frequency for the devfreq object if - userspace governor is in effect. + echo 0 > /sys/class/devfreq/.../trans_stat + + If the transition table is bigger than PAGE_SIZE, reading + this will return an -EFBIG error. What: /sys/class/devfreq/.../available_frequencies Date: October 2012 @@ -98,3 +90,45 @@ Description: frequency requested by governors and min_freq. The max_freq overrides min_freq because max_freq may be used to throttle devices to avoid overheating. + +What: /sys/class/devfreq/.../polling_interval +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../polling_interval shows and sets + the requested polling interval of the corresponding devfreq + object. The values are represented in ms. If the value is + less than 1 jiffy, it is considered to be 0, which means + no polling. This value is meaningless if the governor is + not polling. + + A list of governors that support the node: + - simple_ondmenad + - tegra_actmon + +What: /sys/class/devfreq/.../userspace/set_freq +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../userspace/set_freq shows and + sets the requested frequency for the devfreq object if + userspace governor is in effect. + + A list of governors that support the node: + - userspace + +What: /sys/class/devfreq/.../timer +Date: July 2020 +Contact: Chanwoo Choi <cw00.choi@samsung.com> +Description: + This ABI shows and stores the kind of work timer by users. + This work timer is used by devfreq workqueue in order to + monitor the device status such as utilization. The user + can change the work timer on runtime according to their demand + as following:: + + echo deferrable > /sys/class/devfreq/.../timer + echo delayed > /sys/class/devfreq/.../timer + + A list of governors that support the node: + - simple_ondemand |