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| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-18 18:05:28 -0300 |
|---|---|---|
| committer | Zhang Rui <rui.zhang@intel.com> | 2019-06-27 21:22:15 +0800 |
| commit | 6bbe6f5732faeabb4bb583726ec2d7f9739532bd (patch) | |
| tree | 18a6fd0f79ec2f7363376cb88eaec3d4500221b8 /Documentation/thermal/exynos_thermal_emulation.rst | |
| parent | 57c5b2ec905933da84fe77b2b54619567ac21297 (diff) | |
| download | linux-6bbe6f5732faeabb4bb583726ec2d7f9739532bd.tar.bz2 | |
docs: thermal: convert to ReST
Rename the thermal documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Diffstat (limited to 'Documentation/thermal/exynos_thermal_emulation.rst')
| -rw-r--r-- | Documentation/thermal/exynos_thermal_emulation.rst | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/Documentation/thermal/exynos_thermal_emulation.rst b/Documentation/thermal/exynos_thermal_emulation.rst new file mode 100644 index 000000000000..c21d10838bc5 --- /dev/null +++ b/Documentation/thermal/exynos_thermal_emulation.rst @@ -0,0 +1,61 @@ +===================== +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 |