62 lines
2.2 KiB
ReStructuredText
62 lines
2.2 KiB
ReStructuredText
|
=====================
|
||
|
|
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_THERMAL_EMULATION option will make this support
|
||
|
|
available. When it's enabled, sysfs node will be created as
|
||
|
|
/sys/devices/virtual/thermal/thermal_zone'zone id'/emul_temp.
|
||
|
|
|
||
|
|
The sysfs node, 'emul_node', 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 changeable 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
|