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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-03 02:18:04 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-03 02:18:04 +0300
commitf73cd9c951a9dc23f0ee1260fef5cc61d2825fb3 (patch)
tree8fd3a1fc6f7fdca648b475b42b2b8f4b44061c09 /Documentation/driver-api
parent833db72142b93a89211c1e43ca0a1e2e16457756 (diff)
parent46e9f92f31e67385fab8b49c030635415f36b362 (diff)
downloadlinux-f73cd9c951a9dc23f0ee1260fef5cc61d2825fb3.tar.xz
Merge tag 'thermal-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull thermal control updates from Rafael Wysocki: "These extend the thermal trip point crossing notifications sent via netlink to contain the temperature causing the trip point to be crossed, deprecate the user space thermal governor, add new DT bindings to drivers, move ABI documentation to Documentation/ABI, fix assorted issues and clean up code. Specifics: - Constify a variable in thermal MMIO driver (Rikard Falkeborn). - Add the current temperature in the netlink message when crossing a trip point in order to prevent useless back and forth reading from userspace (Daniel Lezcano). - Add support for the 'HC' variant on PM8998 PMIC in order to support VADC channels on recent QCom boards (Bjorn Andersson). - Add support for calibration values from hardware when they are fused (Niklas Söderlund). - Fix NULL pointer dereference in the thermal_release callback when an error occurs in the thermal_zone_device_register() (Yuanzheng Song). - Fix use-after-free in __thermal_cooling_device_register() in the error path (Ziyang Xuan). - Fix compilation of the LMh driver when CONFIG_QCOM_SCM is not set (Jackie Liu). - Add timeout when reading a register that can block forever in certain circumstances in the tsens driver (Ansuel Smith). - Add DT binding for the reset lines and use them in the rockchip sensor driver (Johan Jonker). - Add new uniphier NX1 SoC temperature sensor (Kunihiko Hayashi). - Save and restore the TCC value in the int340x driver (Antoine Tenart). - Deprecate the writability of the cooling device state sysfs file and the user space governor (Daniel Lezcano). - Delete bogus length check in int340x (Dan Carpenter). - Use bitmap_zalloc/bitmap_free when applicable in intel_powerclamp (Christophe JAILLET). - Move thermal ABI documentation to Documentation/ABI (Mauro Carvalho Chehab)" * tag 'thermal-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (21 commits) thermal/core: Deprecate changing cooling device state from userspace thermal/core: Make the userspace governor deprecated thermal/drivers/int340x: Improve the tcc offset saving for suspend/resume thermal/drivers/uniphier: Add compatible string for NX1 SoC dt-bindings: thermal: uniphier: Add binding for NX1 SoC thermal/drivers/rockchip_thermal: Allow more resets for tsadc node dt-bindings: thermal: remove redundant comments from rockchip-thermal.yaml dt-bindings: thermal: allow more resets for tsadc node in rockchip-thermal.yaml thermal/drivers/tsens: Add timeout to get_temp_tsens_valid thermal/drivers/qcom/lmh: make QCOM_LMH depends on QCOM_SCM thermal/core: fix a UAF bug in __thermal_cooling_device_register() thermal/core: Fix null pointer dereference in thermal_release() thermal: rcar_gen3_thermal: Read calibration from hardware thermal: rcar_gen3_thermal: Store thcode and ptat in priv data thermal/drivers/qcom/spmi-adc-tm5: Add support for HC variant dt-bindings: thermal: qcom: add HC variant of adc-thermal monitor bindings thermal: Move ABI documentation to Documentation/ABI thermal/drivers/netlink: Add the temperature when crossing a trip point thermal/drivers/thermal_mmio: Constify static struct thermal_mmio_ops thermal: int340x: delete bogus length check ...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/thermal/sysfs-api.rst225
1 files changed, 3 insertions, 222 deletions
diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
index c93fa5e961a0..2e0f79a9e2ee 100644
--- a/Documentation/driver-api/thermal/sysfs-api.rst
+++ b/Documentation/driver-api/thermal/sysfs-api.rst
@@ -428,6 +428,9 @@ of thermal zone device. E.g. the generic thermal driver registers one hwmon
class device and build the associated hwmon sysfs I/F for all the registered
ACPI thermal zones.
+Please read Documentation/ABI/testing/sysfs-class-thermal for thermal
+zone and cooling device attribute details.
+
::
/sys/class/hwmon/hwmon[0-*]:
@@ -437,228 +440,6 @@ ACPI thermal zones.
Please read Documentation/hwmon/sysfs-interface.rst for additional information.
-Thermal zone attributes
------------------------
-
-type
- Strings which represent the thermal zone type.
- This is given by thermal zone driver as part of registration.
- E.g: "acpitz" indicates it's an ACPI thermal device.
- In order to keep it consistent with hwmon sys attribute; this should
- be a short, lowercase string, not containing spaces nor dashes.
- RO, Required
-
-temp
- Current temperature as reported by thermal zone (sensor).
- Unit: millidegree Celsius
- RO, Required
-
-mode
- One of the predefined values in [enabled, disabled].
- This file gives information about the algorithm that is currently
- managing the thermal zone. It can be either default kernel based
- algorithm or user space application.
-
- enabled
- enable Kernel Thermal management.
- disabled
- Preventing kernel thermal zone driver actions upon
- trip points so that user application can take full
- charge of the thermal management.
-
- RW, Optional
-
-policy
- One of the various thermal governors used for a particular zone.
-
- RW, Required
-
-available_policies
- Available thermal governors which can be used for a particular zone.
-
- RO, Required
-
-`trip_point_[0-*]_temp`
- The temperature above which trip point will be fired.
-
- Unit: millidegree Celsius
-
- RO, Optional
-
-`trip_point_[0-*]_type`
- Strings which indicate the type of the trip point.
-
- E.g. it can be one of critical, hot, passive, `active[0-*]` for ACPI
- thermal zone.
-
- RO, Optional
-
-`trip_point_[0-*]_hyst`
- The hysteresis value for a trip point, represented as an integer
- Unit: Celsius
- RW, Optional
-
-`cdev[0-*]`
- Sysfs link to the thermal cooling device node where the sys I/F
- for cooling device throttling control represents.
-
- RO, Optional
-
-`cdev[0-*]_trip_point`
- The trip point in this thermal zone which `cdev[0-*]` is associated
- with; -1 means the cooling device is not associated with any trip
- point.
-
- RO, Optional
-
-`cdev[0-*]_weight`
- The influence of `cdev[0-*]` in this thermal zone. This value
- is relative to the rest of cooling devices in the thermal
- zone. For example, if a cooling device has a weight double
- than that of other, it's twice as effective in cooling the
- thermal zone.
-
- RW, Optional
-
-emul_temp
- Interface to set the emulated temperature method in thermal zone
- (sensor). After setting this temperature, the thermal zone may pass
- this temperature to platform emulation function if registered or
- cache it locally. This is useful in debugging different temperature
- threshold and its associated cooling action. This is write only node
- and writing 0 on this node should disable emulation.
- Unit: millidegree Celsius
-
- WO, Optional
-
- WARNING:
- Be careful while enabling this option on production systems,
- because userland can easily disable the thermal policy by simply
- flooding this sysfs node with low temperature values.
-
-sustainable_power
- An estimate of the sustained power that can be dissipated by
- the thermal zone. Used by the power allocator governor. For
- more information see Documentation/driver-api/thermal/power_allocator.rst
-
- Unit: milliwatts
-
- RW, Optional
-
-k_po
- The proportional term of the power allocator governor's PID
- controller during temperature overshoot. Temperature overshoot
- is when the current temperature is above the "desired
- temperature" trip point. For more information see
- Documentation/driver-api/thermal/power_allocator.rst
-
- RW, Optional
-
-k_pu
- The proportional term of the power allocator governor's PID
- controller during temperature undershoot. Temperature undershoot
- is when the current temperature is below the "desired
- temperature" trip point. For more information see
- Documentation/driver-api/thermal/power_allocator.rst
-
- RW, Optional
-
-k_i
- The integral term of the power allocator governor's PID
- controller. This term allows the PID controller to compensate
- for long term drift. For more information see
- Documentation/driver-api/thermal/power_allocator.rst
-
- RW, Optional
-
-k_d
- The derivative term of the power allocator governor's PID
- controller. For more information see
- Documentation/driver-api/thermal/power_allocator.rst
-
- RW, Optional
-
-integral_cutoff
- Temperature offset from the desired temperature trip point
- above which the integral term of the power allocator
- governor's PID controller starts accumulating errors. For
- example, if integral_cutoff is 0, then the integral term only
- accumulates error when temperature is above the desired
- temperature trip point. For more information see
- Documentation/driver-api/thermal/power_allocator.rst
-
- Unit: millidegree Celsius
-
- RW, Optional
-
-slope
- The slope constant used in a linear extrapolation model
- to determine a hotspot temperature based off the sensor's
- raw readings. It is up to the device driver to determine
- the usage of these values.
-
- RW, Optional
-
-offset
- The offset constant used in a linear extrapolation model
- to determine a hotspot temperature based off the sensor's
- raw readings. It is up to the device driver to determine
- the usage of these values.
-
- RW, Optional
-
-Cooling device attributes
--------------------------
-
-type
- String which represents the type of device, e.g:
-
- - for generic ACPI: should be "Fan", "Processor" or "LCD"
- - for memory controller device on intel_menlow platform:
- should be "Memory controller".
-
- RO, Required
-
-max_state
- The maximum permissible cooling state of this cooling device.
-
- RO, Required
-
-cur_state
- The current cooling state of this cooling device.
- The value can any integer numbers between 0 and max_state:
-
- - cur_state == 0 means no cooling
- - cur_state == max_state means the maximum cooling.
-
- RW, Required
-
-stats/reset
- Writing any value resets the cooling device's statistics.
- WO, Required
-
-stats/time_in_state_ms:
- The amount of time spent by the cooling device in various cooling
- states. The output will have "<state> <time>" pair in each line, which
- will mean this cooling device spent <time> msec of time at <state>.
- Output will have one line for each of the supported states.
- RO, Required
-
-
-stats/total_trans:
- A single positive value showing the total number of times the state of a
- cooling device is changed.
-
- RO, Required
-
-stats/trans_table:
- This gives fine grained information about all the cooling state
- transitions. The cat output here is a two dimensional matrix, where an
- entry <i,j> (row i, column j) represents the number of transitions from
- State_i to State_j. If the transition table is bigger than PAGE_SIZE,
- reading this will return an -EFBIG error.
- RO, Required
-
3. A simple implementation
==========================