This patch use the phandle to find the instance of devfreq-event device in
Device Tree when calling the devfreq_event_get_edev_by_phandle() because there
is two type devfreq-event devices as following:
First case, exynos-ppmu.c driver provides the maximum four event of each PPMU.
So, when getting the instance of devfreq-event device, using the unique name of
struct devfreq_event_desc.
Second case, exynos-nocp.c driver provide the only one event of each NoC Probe
device. So, when getting the instance of devfreq-event device, using the
phandle of each NoC probe device.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This patch just fixes following error and warning by using
scripts/checkpatch.pl.
- Follwoing issue from checkpatch.pl:
ERROR: space prohibited before that close parenthesis ')'
+ if (count < 0 ) {
WARNING: line over 80 characters
+ ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This patch just removes the error log when
devfreq_event_get_edev_by_phandle() fail to get the instance of
devfreq-event device. It is related to sequence of the probe() of each
driver. So, this error log might show the always during kernel booting.
Each driver using this function can show the appropriate error log.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This patch adds a new class in devfreq, devfreq_event, which provides
raw data (e.g., memory bus utilization, GPU utilization) for devfreq
governors.
- devfreq_event device : Provides raw data for a governor of a devfreq device
- devfreq device : Monitors device state and changes frequency/voltage
of the device using the raw data from its
devfreq_event device.
A devfreq device dertermines performance states (normally the frequency
and the voltage vlues) based on the results its designtated devfreq governor:
e.g., ondemand, performance, powersave.
In order to give such results required by a devfreq device, the devfreq
governor requires data that indicates the performance requirement given
to the devfreq device. The conventional (previous) implementatino of
devfreq subsystem requires a devfreq device driver to implement its own
mechanism to acquire performance requirement for its governor. However,
there had been issues with such requirements:
1. Although performance requirement of such devices is usually acquired
from common devices (PMU/PPMU), we do not have any abstract structure to
represent them properly.
2. Such performance requirement devices (PMU/PPMU) are actual hardware
pieces that may be represented by Device Tree directly while devfreq device
itself is a virtual entity that are not considered to be represented by
Device Tree according to Device Tree folks.
In order to address such issues, a devferq_event device (represented by
this patch) provides a template for device drivers representing
performance monitoring unit, which gives the basic or raw data for
preformance requirement, which in turn, is required by devfreq governors.
The following description explains the feature of two kind of devfreq class:
- devfreq class (existing)
: devfreq consumer device use raw data from devfreq_event device for
determining proper current system state and change voltage/frequency
dynamically using various governors.
- devfreq_event class (new)
: Provide measured raw data to devfreq device for governor
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[Commit message rewritten & conflict resolved by MyungJoo]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
