This patch introduces a new interface for device drivers connected to
devfreq_cooling in the thermal framework: get_real_power().
Some devices have more sophisticated methods (like power counters)
to approximate the actual power that they use.
In the previous implementation we had a pre-calculated power
table which was then scaled by 'utilization'
('busy_time' and 'total_time' taken from devfreq 'last_status').
With this new interface the driver can provide more precise data
regarding actual power to the thermal governor every time the power
budget is calculated. We then use this value and calculate the real
resource utilization scaling factor.
Reviewed-by: Chris Diamand <chris.diamand@arm.com>
Acked-by: Javi Merino <javi.merino@kernel.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
When the devfreq cooling device was designed, it was an oversight not to
pass a pointer to the struct devfreq as the first parameters of the
callbacks. The design patterns of the kernel suggest it for a good
reason.
By passing a pointer to struct devfreq, the driver can register one
function that works with multiple devices. With the current
implementation, a driver that can work with multiple devices has to
create multiple copies of the same function with different parameters so
that each devfreq_cooling_device can use the appropriate one. By
passing a pointer to struct devfreq, the driver can identify which
device it's referring to.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Ørjan Eide <orjan.eide@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Currently the protection #ifdef CONFIG_DEVFREQ_THERMAL cuts the needed
structures devfreq_cooling_ops and devfreq_cooling_device.
The functions which are supposed to provide the empty implementation complain
about unknown structures.
Similar solution is present in include/linux/devfreq.h.
Reviewed-by: Ørjan Eide <orjan.eide@arm.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Be consistent with what other cooling devices do and return a struct
thermal_cooling_device * on register. Also, for the unregister, accept
a struct thermal_cooling_device * as parameter.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Add a generic thermal cooling device for devfreq, that is similar to
cpu_cooling.
The device must use devfreq. In order to use the power extension of the
cooling device, it must have registered its OPPs using the OPP library.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Ørjan Eide <orjan.eide@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Lukasz Luba