mirror of https://gitee.com/openkylin/linux.git
54 lines
2.2 KiB
Plaintext
54 lines
2.2 KiB
Plaintext
|
EXYNOS EMULATION MODE
|
||
|
|
========================
|
||
|
|
|
||
|
|
Copyright (C) 2012 Samsung Electronics
|
||
|
|
|
||
|
|
Written by Jonghwa Lee <jonghwa3.lee@samsung.com>
|
||
|
|
|
||
|
|
Description
|
||
|
|
-----------
|
||
|
|
|
||
|
|
Exynos 4x12 (4212, 4412) and 5 series provide emulation mode for thermal management unit.
|
||
|
|
Thermal emulation mode supports software debug for TMU's operation. User can set temperature
|
||
|
|
manually with software code and TMU will read current temperature from user value not from
|
||
|
|
sensor's value.
|
||
|
|
|
||
|
|
Enabling CONFIG_EXYNOS_THERMAL_EMUL option will make this support in available.
|
||
|
|
When it's enabled, sysfs node will be created under
|
||
|
|
/sys/bus/platform/devices/'exynos device name'/ with name of 'emulation'.
|
||
|
|
|
||
|
|
The sysfs node, 'emulation', will contain value 0 for the initial state. When you input any
|
||
|
|
temperature you want to update to sysfs node, it automatically enable emulation mode and
|
||
|
|
current temperature will be changed into it.
|
||
|
|
(Exynos also supports user changable delay time which would be used to delay of
|
||
|
|
changing temperature. However, this node only uses same delay of real sensing time, 938us.)
|
||
|
|
|
||
|
|
Exynos emulation mode requires synchronous of value changing and enabling. It means when you
|
||
|
|
want to update the any value of delay or next temperature, then you have to enable emulation
|
||
|
|
mode at the same time. (Or you have to keep the mode enabling.) If you don't, it fails to
|
||
|
|
change the value to updated one and just use last succeessful value repeatedly. That's why
|
||
|
|
this node gives users the right to change termerpature only. Just one interface makes it more
|
||
|
|
simply to use.
|
||
|
|
|
||
|
|
Disabling emulation mode only requires writing value 0 to sysfs node.
|
||
|
|
|
||
|
|
|
||
|
|
TEMP 120 |
|
||
|
|
|
|
||
|
|
100 |
|
||
|
|
|
|
||
|
|
80 |
|
||
|
|
| +-----------
|
||
|
|
60 | | |
|
||
|
|
| +-------------| |
|
||
|
|
40 | | | |
|
||
|
|
| | | |
|
||
|
|
20 | | | +----------
|
||
|
|
| | | | |
|
||
|
|
0 |______________|_____________|__________|__________|_________
|
||
|
|
A A A A TIME
|
||
|
|
|<----->| |<----->| |<----->| |
|
||
|
|
| 938us | | | | | |
|
||
|
|
emulation : 0 50 | 70 | 20 | 0
|
||
|
|
current temp : sensor 50 70 20 sensor
|