The bang-bang thermal governor uses a hysteresis to switch abruptly on
or off a cooling device.  It is intended to control fans, which can
not be throttled but just switched on or off.
Bang-bang cannot be set as default governor as it is intended for
special devices only.  For those special devices the driver needs to
explicitely request it.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Andreas Mohr <andi@lisas.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Javi Merino <javi.merino@arm.com>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Peter Feuerer <peter@piie.net>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

Create a new event to trace when the temperature is above a trip
point. Use the trace-point when handling non-critical and critical
trip pionts.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Introduce and use an event to trace when a cooling device's state is
updated. This is useful to follow the effect of governor decisions on
cooling devices.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Create a new event to trace the temperature of a thermal zone. Using
this event trace the temperature changes of the thermal zone every-time
it is updated.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

This patch does a cleanup about the thermal zone govenor,
setting and make the following rule.
1. For thermal zone devices that are registered w/o tz->tzp,
   they can use the default thermal governor only.
2. For thermal zone devices w/ governor name specified in
   tz->tzp->governor_name, we will use the default govenor
   if the governor specified is not available at the moment,
   and update tz->governor when the matched governor is registered.

This also fixes a problem that OF registered thermal zones
are running with no governor.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Javi Merino <javi.merino@arm.com>

In initialization, if the cooling device is initialized at
max cooling state, and the thermal zone temperature is below
the first trip point, then the cooling state can't be updated
to the right state, untill the first trip point be triggered.

To fix this issue, allow first update of cooling device state
during registration, initialized "updated" device field as
"false" (instead of "true").
Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch is to update thermal zone device after setting emul_temp
in order to make governor work according to input temperature immediately.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.

Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671

A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:

[  355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[  355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[  355.147644] get_target_state: thermal cooling_device8: cur_state=0
[  355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[  355.147652] get_target_state: thermal cooling_device7: cur_state=0
[  355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[  355.147660] get_target_state: thermal cooling_device6: cur_state=0
[  355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[  355.147668] get_target_state: thermal cooling_device5: cur_state=0
[  355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[  355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[  355.147776] get_target_state: thermal cooling_device0: cur_state=0
[  355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[  355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[  355.147845] get_target_state: thermal cooling_device1: cur_state=0
[  355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[  355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[  355.147904] get_target_state: thermal cooling_device2: cur_state=0
[  355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[  355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[  355.147963] get_target_state: thermal cooling_device3: cur_state=0
[  355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[  355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[  355.148022] get_target_state: thermal cooling_device4: cur_state=0
[  355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[  355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[  355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch adds a new API to allow registering cooling devices
in the thermal framework derived from device tree nodes.

This API links the cooling device with the device tree node
so that binding with thermal zones is possible, given
that thermal zones are pointing to cooling device
device tree nodes.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

This patch introduces a device tree bindings for
describing the hardware thermal behavior and limits.
Also a parser to read and interpret the data and feed
it in the thermal framework is presented.

This patch introduces a thermal data parser for device
tree. The parsed data is used to build thermal zones
and thermal binding parameters. The output data
can then be used to deploy thermal policies.

This patch adds also documentation regarding this
API and how to define tree nodes to use
this infrastructure.

Note that, in order to be able to have control
on the sensor registration on the DT thermal zone,
it was required to allow changing the thermal zone
.get_temp callback. For this reason, this patch
also removes the 'const' modifier from the .ops
field of thermal zone devices.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

This patch changes the thermal core driver to allow
registration of thermal zones without the .get_temp callback.

The idea behind this change is to allow lazy registration
of sensor callbacks.

The thermal zone will be disabled whenever the ops
does not contain a .get_temp callback. The sysfs interface
will be returning -EINVAL on any temperature read operation.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

Register generic netlink multicast groups as an array with
the family and give them contiguous group IDs. Then instead
of passing the global group ID to the various functions that
send messages, pass the ID relative to the family - for most
families that's just 0 because the only have one group.

This avoids the list_head and ID in each group, adding a new
field for the mcast group ID offset to the family.

At the same time, this allows us to prevent abusing groups
again like the quota and dropmon code did, since we can now
check that a family only uses a group it owns.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This doesn't really change anything, but prepares for the
next patch that will change the APIs to pass the group ID
within the family, rather than the global group ID.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The thermal zone params can be used to set governor
to specific thermal governor for thermal zone device.
But if the thermal zone params has only governor name
without thermal bind params, then the thermal zone device
will not be binding to cooling device. Because tz->ops->bind
operator is not invoked in bind_tz() and bind_cdev() when
there is thermal zone params.
Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Jinyoung Park <jinyoungp@nvidia.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

The thermal_release function is called whenever
any device belonging to 'thermal' class unregisters.
This function performs kfree(cdev) without any check.
In cases where there are more device registrations
other than just 'thermal_zone' and 'cooling_device'
this might accidently free memory allocated them
silently; and cause memory errors.

This patch changes this behavior by doing
kfree(cdev) only when the device pointer belongs
to a real cdev i.e. cooling_device.
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

When registering a thermal zone device using platform information
via bind_params, the thermal framework will always perform the
cdev binding using the lowest and highest limits (THERMAL_NO_LIMIT).

This patch changes the data structures so that it is possible
to inform what are the desired limits for each trip point
inside a bind_param. The way the binding is performed is also
changed so that it uses the new data structure.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

When registering a new thermal_device, the thermal framework
will always add a hwmon sysfs interface.

This patch adds a flag to make this behavior optional. Now
when registering a new thermal device, the caller can
optionally inform if hwmon interface is desirable. This can
be done by means of passing a thermal_zone_params.no_hwmon == true.

In order to keep same behavior as of today, all current
calls will by default create the hwmon interface.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Zhang Rui <rui.zhang@intel.com>
Suggested-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

In order to improve code organization, this patch
moves the hwmon sysfs support to a file named
thermal_hwmon. This helps to add extra support
for hwmon without scrambling the code.

In order to do this move, the hwmon list head is now
using its own locking. Before, the list used
the global thermal locking. Also, some minor changes
in the code were required, as recommended by checkpatch.pl.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

In case emulated temperature is in use, using the trend
provided by driver layer can lead to bogus situation.
In this case, debugger user would set a temperature value,
but the trend would be from driver computation.

To avoid this situation, this patch changes the get_tz_trend()
to consider the emulated temperature whenever that is in use.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch adds a requirement needing .get_trip_temp() callback
function for registering thermal zone device. This function is
used when thermal zone is updated and essential where thermal core
handles thermal trip based only polling way not hw interrupt.
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

Setting policy results in invalid value error.
	% echo "step_wise" > policy
	% echo: write error: Invalid argument

Need clean up of the buffer which "echo" may add based on the arguments, before
comparing aganist list of governor names.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Tested-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch changes the driver to avoid the usage of IS_ERR_OR_NULL()
macro. This macro can lead to dangerous results, like returning
success (0) during a failure scenario (NULL pointer handling).

The case present in this patch has simply be translated to
normal check for NULL and if the pointer has an error code.
The later case is needed because functions like
thermal_zone_get_zone_by_name() could return an ERR_PTR().

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch updates the documentation for thermal_zone_device_register
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch updates the documentation for create_trip_attrs
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch updates the documentation for thermal_cooling_device_register
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch updates the documentation for thermal_zone_unbind_cooling_device
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch updates the documentation for thermal_zone_bind_cooling_device
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

Restrict usage of GPL modules.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

To follow the prefix names used by the thermal functions,
this patch renames notify_thermal_framework to thermal_notify_framework.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

As per the comment at the top of this file, this is a GPLv2 driver.
This patch updates the driver license accordingly.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

For memory boundaries safety, use strlcpy instead of strcpy.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch exports the thermal_zone_get_temp API so that driver
writers can fetch temperature of thermal zones managed by other
drivers.
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch adds a helper function to get a reference of
a thermal zone, based on the zone type name.

It will perform a zone name lookup and return a reference
to a thermal zone device that matches the name requested.
In case the zone is not found or when several zones match
same name or if the required parameters are invalid, it will return
the corresponding error code (ERR_PTR).

Cc: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

The thermal governors are part of the thermal framework,
rather than a seperate feature/module.
Because the generic thermal layer can not work without
thermal governors, and it must load the thermal governors
during its initialization.

Build them into one module in this patch.

This also fix a problem that the generic thermal layer does not
work when CONFIG_THERMAL=m and CONFIG_THERMAL_GOV_XXX=y.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Durgadoss R <durgadoss.r@intel.com>

this is the preparation work to build all the thermal core framework
source file, like governors, cpu cooling, etc, into one module.

No functional change in this patch.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Durgadoss R <durgadoss.r@intel.com>

Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The return code from the registration of the thermal class is used to
unallocate resources, but this failure isn't passed back to the caller of
thermal_init.  Return this failure back to the caller.

This bug was introduced in changeset 4cb18728 which overwrote the return code
when the variable was re-used to catch the return code of the registration of
the genetlink thermal socket family.
Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch adds support to set the emulated temperature method in
thermal zone (sensor). After setting this feature thermal zone may
report this temperature and not the actual temperature. The emulation
implementation may be based on sensor capability through platform
specific handler or pure software emulation if no platform handler defined.

This is useful in debugging different temperature threshold and its
associated cooling action. Critical threshold's cannot be emulated.
Writing 0 on this node should disable emulation.
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

This patch adds an extra check in the data structure while registering
a thermal device. The check is to avoid registering zones with a number
of trips greater than zero, but with no .get_trip_temp nor .get_trip_type
callbacks. Receiving such data structure may end in wrong data access.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>