Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 1551 insertions, 0 deletions

diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt
new file mode 100644
index 000000000..7df567eae
--- /dev/null
+++ b/Documentation/thermal/cpu-cooling-api.txt
@@ -0,0 +1,92 @@
+CPU cooling APIs How To
+===================================
+
+Written by Amit Daniel Kachhap <amit.kachhap@linaro.org>
+
+Updated: 6 Jan 2015
+
+Copyright (c)  2012 Samsung Electronics Co., Ltd(http://www.samsung.com)
+
+0. Introduction
+
+The generic cpu cooling(freq clipping) provides registration/unregistration APIs
+to the caller. The binding of the cooling devices to the trip point is left for
+the user. The registration APIs returns the cooling device pointer.
+
+1. cpu cooling APIs
+
+1.1 cpufreq registration/unregistration APIs
+1.1.1 struct thermal_cooling_device *cpufreq_cooling_register(
+	struct cpumask *clip_cpus)
+
+    This interface function registers the cpufreq cooling device with the name
+    "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+    cooling devices.
+
+   clip_cpus: cpumask of cpus where the frequency constraints will happen.
+
+1.1.2 struct thermal_cooling_device *of_cpufreq_cooling_register(
+					struct cpufreq_policy *policy)
+
+    This interface function registers the cpufreq cooling device with
+    the name "thermal-cpufreq-%x" linking it with a device tree node, in
+    order to bind it via the thermal DT code. This api can support multiple
+    instances of cpufreq cooling devices.
+
+    policy: CPUFreq policy.
+
+1.1.3 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
+
+    This interface function unregisters the "thermal-cpufreq-%x" cooling device.
+
+    cdev: Cooling device pointer which has to be unregistered.
+
+2. Power models
+
+The power API registration functions provide a simple power model for
+CPUs.  The current power is calculated as dynamic power (static power isn't
+supported currently).  This power model requires that the operating-points of
+the CPUs are registered using the kernel's opp library and the
+`cpufreq_frequency_table` is assigned to the `struct device` of the
+cpu.  If you are using CONFIG_CPUFREQ_DT then the
+`cpufreq_frequency_table` should already be assigned to the cpu
+device.
+
+The dynamic power consumption of a processor depends on many factors.
+For a given processor implementation the primary factors are:
+
+- The time the processor spends running, consuming dynamic power, as
+  compared to the time in idle states where dynamic consumption is
+  negligible.  Herein we refer to this as 'utilisation'.
+- The voltage and frequency levels as a result of DVFS.  The DVFS
+  level is a dominant factor governing power consumption.
+- In running time the 'execution' behaviour (instruction types, memory
+  access patterns and so forth) causes, in most cases, a second order
+  variation.  In pathological cases this variation can be significant,
+  but typically it is of a much lesser impact than the factors above.
+
+A high level dynamic power consumption model may then be represented as:
+
+Pdyn = f(run) * Voltage^2 * Frequency * Utilisation
+
+f(run) here represents the described execution behaviour and its
+result has a units of Watts/Hz/Volt^2 (this often expressed in
+mW/MHz/uVolt^2)
+
+The detailed behaviour for f(run) could be modelled on-line.  However,
+in practice, such an on-line model has dependencies on a number of
+implementation specific processor support and characterisation
+factors.  Therefore, in initial implementation that contribution is
+represented as a constant coefficient.  This is a simplification
+consistent with the relative contribution to overall power variation.
+
+In this simplified representation our model becomes:
+
+Pdyn = Capacitance * Voltage^2 * Frequency * Utilisation
+
+Where `capacitance` is a constant that represents an indicative
+running time dynamic power coefficient in fundamental units of
+mW/MHz/uVolt^2.  Typical values for mobile CPUs might lie in range
+from 100 to 500.  For reference, the approximate values for the SoC in
+ARM's Juno Development Platform are 530 for the Cortex-A57 cluster and
+140 for the Cortex-A53 cluster.
diff --git a/Documentation/thermal/exynos_thermal b/Documentation/thermal/exynos_thermal
new file mode 100644
index 000000000..9010c4416
--- /dev/null
+++ b/Documentation/thermal/exynos_thermal
@@ -0,0 +1,77 @@
+Kernel driver exynos_tmu
+=================
+
+Supported chips:
+* ARM SAMSUNG EXYNOS4, EXYNOS5 series of SoC
+  Datasheet: Not publicly available
+
+Authors: Donggeun Kim <dg77.kim@samsung.com>
+Authors: Amit Daniel <amit.daniel@samsung.com>
+
+TMU controller Description:
+---------------------------
+
+This driver allows to read temperature inside SAMSUNG EXYNOS4/5 series of SoC.
+
+The chip only exposes the measured 8-bit temperature code value
+through a register.
+Temperature can be taken from the temperature code.
+There are three equations converting from temperature to temperature code.
+
+The three equations are:
+  1. Two point trimming
+	Tc = (T - 25) * (TI2 - TI1) / (85 - 25) + TI1
+
+  2. One point trimming
+	Tc = T + TI1 - 25
+
+  3. No trimming
+	Tc = T + 50
+
+  Tc: Temperature code, T: Temperature,
+  TI1: Trimming info for 25 degree Celsius (stored at TRIMINFO register)
+       Temperature code measured at 25 degree Celsius which is unchanged
+  TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register)
+       Temperature code measured at 85 degree Celsius which is unchanged
+
+TMU(Thermal Management Unit) in EXYNOS4/5 generates interrupt
+when temperature exceeds pre-defined levels.
+The maximum number of configurable threshold is five.
+The threshold levels are defined as follows:
+  Level_0: current temperature > trigger_level_0 + threshold
+  Level_1: current temperature > trigger_level_1 + threshold
+  Level_2: current temperature > trigger_level_2 + threshold
+  Level_3: current temperature > trigger_level_3 + threshold
+
+  The threshold and each trigger_level are set
+  through the corresponding registers.
+
+When an interrupt occurs, this driver notify kernel thermal framework
+with the function exynos_report_trigger.
+Although an interrupt condition for level_0 can be set,
+it can be used to synchronize the cooling action.
+
+TMU driver description:
+-----------------------
+
+The exynos thermal driver is structured as,
+
+					Kernel Core thermal framework
+				(thermal_core.c, step_wise.c, cpu_cooling.c)
+								^
+								|
+								|
+TMU configuration data -------> TMU Driver  <------> Exynos Core thermal wrapper
+(exynos_tmu_data.c)	      (exynos_tmu.c)	   (exynos_thermal_common.c)
+(exynos_tmu_data.h)	      (exynos_tmu.h)	   (exynos_thermal_common.h)
+
+a) TMU configuration data: This consist of TMU register offsets/bitfields
+		described through structure exynos_tmu_registers. Also several
+		other platform data (struct exynos_tmu_platform_data) members
+		are used to configure the TMU.
+b) TMU driver: This component initialises the TMU controller and sets different
+		thresholds. It invokes core thermal implementation with the call
+		exynos_report_trigger.
+c) Exynos Core thermal wrapper: This provides 3 wrapper function to use the
+		Kernel core thermal framework. They are exynos_unregister_thermal,
+		exynos_register_thermal and exynos_report_trigger.
diff --git a/Documentation/thermal/exynos_thermal_emulation b/Documentation/thermal/exynos_thermal_emulation
new file mode 100644
index 000000000..b15efec6c
--- /dev/null
+++ b/Documentation/thermal/exynos_thermal_emulation
@@ -0,0 +1,53 @@
+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
diff --git a/Documentation/thermal/intel_powerclamp.txt b/Documentation/thermal/intel_powerclamp.txt
new file mode 100644
index 000000000..b5df21168
--- /dev/null
+++ b/Documentation/thermal/intel_powerclamp.txt
@@ -0,0 +1,317 @@
+			 =======================
+			 INTEL POWERCLAMP DRIVER
+			 =======================
+By: Arjan van de Ven <arjan@linux.intel.com>
+    Jacob Pan <jacob.jun.pan@linux.intel.com>
+
+Contents:
+	(*) Introduction
+	    - Goals and Objectives
+
+	(*) Theory of Operation
+	    - Idle Injection
+	    - Calibration
+
+	(*) Performance Analysis
+	    - Effectiveness and Limitations
+	    - Power vs Performance
+	    - Scalability
+	    - Calibration
+	    - Comparison with Alternative Techniques
+
+	(*) Usage and Interfaces
+	    - Generic Thermal Layer (sysfs)
+	    - Kernel APIs (TBD)
+
+============
+INTRODUCTION
+============
+
+Consider the situation where a system’s power consumption must be
+reduced at runtime, due to power budget, thermal constraint, or noise
+level, and where active cooling is not preferred. Software managed
+passive power reduction must be performed to prevent the hardware
+actions that are designed for catastrophic scenarios.
+
+Currently, P-states, T-states (clock modulation), and CPU offlining
+are used for CPU throttling.
+
+On Intel CPUs, C-states provide effective power reduction, but so far
+they’re only used opportunistically, based on workload. With the
+development of intel_powerclamp driver, the method of synchronizing
+idle injection across all online CPU threads was introduced. The goal
+is to achieve forced and controllable C-state residency.
+
+Test/Analysis has been made in the areas of power, performance,
+scalability, and user experience. In many cases, clear advantage is
+shown over taking the CPU offline or modulating the CPU clock.
+
+
+===================
+THEORY OF OPERATION
+===================
+
+Idle Injection
+--------------
+
+On modern Intel processors (Nehalem or later), package level C-state
+residency is available in MSRs, thus also available to the kernel.
+
+These MSRs are:
+      #define MSR_PKG_C2_RESIDENCY	0x60D
+      #define MSR_PKG_C3_RESIDENCY	0x3F8
+      #define MSR_PKG_C6_RESIDENCY	0x3F9
+      #define MSR_PKG_C7_RESIDENCY	0x3FA
+
+If the kernel can also inject idle time to the system, then a
+closed-loop control system can be established that manages package
+level C-state. The intel_powerclamp driver is conceived as such a
+control system, where the target set point is a user-selected idle
+ratio (based on power reduction), and the error is the difference
+between the actual package level C-state residency ratio and the target idle
+ratio.
+
+Injection is controlled by high priority kernel threads, spawned for
+each online CPU.
+
+These kernel threads, with SCHED_FIFO class, are created to perform
+clamping actions of controlled duty ratio and duration. Each per-CPU
+thread synchronizes its idle time and duration, based on the rounding
+of jiffies, so accumulated errors can be prevented to avoid a jittery
+effect. Threads are also bound to the CPU such that they cannot be
+migrated, unless the CPU is taken offline. In this case, threads
+belong to the offlined CPUs will be terminated immediately.
+
+Running as SCHED_FIFO and relatively high priority, also allows such
+scheme to work for both preemptable and non-preemptable kernels.
+Alignment of idle time around jiffies ensures scalability for HZ
+values. This effect can be better visualized using a Perf timechart.
+The following diagram shows the behavior of kernel thread
+kidle_inject/cpu. During idle injection, it runs monitor/mwait idle
+for a given "duration", then relinquishes the CPU to other tasks,
+until the next time interval.
+
+The NOHZ schedule tick is disabled during idle time, but interrupts
+are not masked. Tests show that the extra wakeups from scheduler tick
+have a dramatic impact on the effectiveness of the powerclamp driver
+on large scale systems (Westmere system with 80 processors).
+
+CPU0
+		  ____________          ____________
+kidle_inject/0   |   sleep    |  mwait |  sleep     |
+	_________|            |________|            |_______
+			       duration
+CPU1
+		  ____________          ____________
+kidle_inject/1   |   sleep    |  mwait |  sleep     |
+	_________|            |________|            |_______
+			      ^
+			      |
+			      |
+			      roundup(jiffies, interval)
+
+Only one CPU is allowed to collect statistics and update global
+control parameters. This CPU is referred to as the controlling CPU in
+this document. The controlling CPU is elected at runtime, with a
+policy that favors BSP, taking into account the possibility of a CPU
+hot-plug.
+
+In terms of dynamics of the idle control system, package level idle
+time is considered largely as a non-causal system where its behavior
+cannot be based on the past or current input. Therefore, the
+intel_powerclamp driver attempts to enforce the desired idle time
+instantly as given input (target idle ratio). After injection,
+powerclamp monitors the actual idle for a given time window and adjust
+the next injection accordingly to avoid over/under correction.
+
+When used in a causal control system, such as a temperature control,
+it is up to the user of this driver to implement algorithms where
+past samples and outputs are included in the feedback. For example, a
+PID-based thermal controller can use the powerclamp driver to
+maintain a desired target temperature, based on integral and
+derivative gains of the past samples.
+
+
+
+Calibration
+-----------
+During scalability testing, it is observed that synchronized actions
+among CPUs become challenging as the number of cores grows. This is
+also true for the ability of a system to enter package level C-states.
+
+To make sure the intel_powerclamp driver scales well, online
+calibration is implemented. The goals for doing such a calibration
+are:
+
+a) determine the effective range of idle injection ratio
+b) determine the amount of compensation needed at each target ratio
+
+Compensation to each target ratio consists of two parts:
+
+        a) steady state error compensation
+	This is to offset the error occurring when the system can
+	enter idle without extra wakeups (such as external interrupts).
+
+	b) dynamic error compensation
+	When an excessive amount of wakeups occurs during idle, an
+	additional idle ratio can be added to quiet interrupts, by
+	slowing down CPU activities.
+
+A debugfs file is provided for the user to examine compensation
+progress and results, such as on a Westmere system.
+[jacob@nex01 ~]$ cat
+/sys/kernel/debug/intel_powerclamp/powerclamp_calib
+controlling cpu: 0
+pct confidence steady dynamic (compensation)
+0	0	0	0
+1	1	0	0
+2	1	1	0
+3	3	1	0
+4	3	1	0
+5	3	1	0
+6	3	1	0
+7	3	1	0
+8	3	1	0
+...
+30	3	2	0
+31	3	2	0
+32	3	1	0
+33	3	2	0
+34	3	1	0
+35	3	2	0
+36	3	1	0
+37	3	2	0
+38	3	1	0
+39	3	2	0
+40	3	3	0
+41	3	1	0
+42	3	2	0
+43	3	1	0
+44	3	1	0
+45	3	2	0
+46	3	3	0
+47	3	0	0
+48	3	2	0
+49	3	3	0
+
+Calibration occurs during runtime. No offline method is available.
+Steady state compensation is used only when confidence levels of all
+adjacent ratios have reached satisfactory level. A confidence level
+is accumulated based on clean data collected at runtime. Data
+collected during a period without extra interrupts is considered
+clean.
+
+To compensate for excessive amounts of wakeup during idle, additional
+idle time is injected when such a condition is detected. Currently,
+we have a simple algorithm to double the injection ratio. A possible
+enhancement might be to throttle the offending IRQ, such as delaying
+EOI for level triggered interrupts. But it is a challenge to be
+non-intrusive to the scheduler or the IRQ core code.
+
+
+CPU Online/Offline
+------------------
+Per-CPU kernel threads are started/stopped upon receiving
+notifications of CPU hotplug activities. The intel_powerclamp driver
+keeps track of clamping kernel threads, even after they are migrated
+to other CPUs, after a CPU offline event.
+
+
+=====================
+Performance Analysis
+=====================
+This section describes the general performance data collected on
+multiple systems, including Westmere (80P) and Ivy Bridge (4P, 8P).
+
+Effectiveness and Limitations
+-----------------------------
+The maximum range that idle injection is allowed is capped at 50
+percent. As mentioned earlier, since interrupts are allowed during
+forced idle time, excessive interrupts could result in less
+effectiveness. The extreme case would be doing a ping -f to generated
+flooded network interrupts without much CPU acknowledgement. In this
+case, little can be done from the idle injection threads. In most
+normal cases, such as scp a large file, applications can be throttled
+by the powerclamp driver, since slowing down the CPU also slows down
+network protocol processing, which in turn reduces interrupts.
+
+When control parameters change at runtime by the controlling CPU, it
+may take an additional period for the rest of the CPUs to catch up
+with the changes. During this time, idle injection is out of sync,
+thus not able to enter package C- states at the expected ratio. But
+this effect is minor, in that in most cases change to the target
+ratio is updated much less frequently than the idle injection
+frequency.
+
+Scalability
+-----------
+Tests also show a minor, but measurable, difference between the 4P/8P
+Ivy Bridge system and the 80P Westmere server under 50% idle ratio.
+More compensation is needed on Westmere for the same amount of
+target idle ratio. The compensation also increases as the idle ratio
+gets larger. The above reason constitutes the need for the
+calibration code.
+
+On the IVB 8P system, compared to an offline CPU, powerclamp can
+achieve up to 40% better performance per watt. (measured by a spin
+counter summed over per CPU counting threads spawned for all running
+CPUs).
+
+====================
+Usage and Interfaces
+====================
+The powerclamp driver is registered to the generic thermal layer as a
+cooling device. Currently, it’s not bound to any thermal zones.
+
+jacob@chromoly:/sys/class/thermal/cooling_device14$ grep . *
+cur_state:0
+max_state:50
+type:intel_powerclamp
+
+cur_state allows user to set the desired idle percentage. Writing 0 to
+cur_state will stop idle injection. Writing a value between 1 and
+max_state will start the idle injection. Reading cur_state returns the
+actual and current idle percentage. This may not be the same value
+set by the user in that current idle percentage depends on workload
+and includes natural idle. When idle injection is disabled, reading
+cur_state returns value -1 instead of 0 which is to avoid confusing
+100% busy state with the disabled state.
+
+Example usage:
+- To inject 25% idle time
+$ sudo sh -c "echo 25 > /sys/class/thermal/cooling_device80/cur_state
+"
+
+If the system is not busy and has more than 25% idle time already,
+then the powerclamp driver will not start idle injection. Using Top
+will not show idle injection kernel threads.
+
+If the system is busy (spin test below) and has less than 25% natural
+idle time, powerclamp kernel threads will do idle injection. Forced
+idle time is accounted as normal idle in that common code path is
+taken as the idle task.
+
+In this example, 24.1% idle is shown. This helps the system admin or
+user determine the cause of slowdown, when a powerclamp driver is in action.
+
+
+Tasks: 197 total,   1 running, 196 sleeping,   0 stopped,   0 zombie
+Cpu(s): 71.2%us,  4.7%sy,  0.0%ni, 24.1%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
+Mem:   3943228k total,  1689632k used,  2253596k free,    74960k buffers
+Swap:  4087804k total,        0k used,  4087804k free,   945336k cached
+
+  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
+ 3352 jacob     20   0  262m  644  428 S  286  0.0   0:17.16 spin
+ 3341 root     -51   0     0    0    0 D   25  0.0   0:01.62 kidle_inject/0
+ 3344 root     -51   0     0    0    0 D   25  0.0   0:01.60 kidle_inject/3
+ 3342 root     -51   0     0    0    0 D   25  0.0   0:01.61 kidle_inject/1
+ 3343 root     -51   0     0    0    0 D   25  0.0   0:01.60 kidle_inject/2
+ 2935 jacob     20   0  696m 125m  35m S    5  3.3   0:31.11 firefox
+ 1546 root      20   0  158m  20m 6640 S    3  0.5   0:26.97 Xorg
+ 2100 jacob     20   0 1223m  88m  30m S    3  2.3   0:23.68 compiz
+
+Tests have shown that by using the powerclamp driver as a cooling
+device, a PID based userspace thermal controller can manage to
+control CPU temperature effectively, when no other thermal influence
+is added. For example, a UltraBook user can compile the kernel under
+certain temperature (below most active trip points).
diff --git a/Documentation/thermal/nouveau_thermal b/Documentation/thermal/nouveau_thermal
new file mode 100644
index 000000000..6e17a11ef
--- /dev/null
+++ b/Documentation/thermal/nouveau_thermal
@@ -0,0 +1,82 @@
+Kernel driver nouveau
+===================
+
+Supported chips:
+* NV43+
+
+Authors: Martin Peres (mupuf) <martin.peres@free.fr>
+
+Description
+---------
+
+This driver allows to read the GPU core temperature, drive the GPU fan and
+set temperature alarms.
+
+Currently, due to the absence of in-kernel API to access HWMON drivers, Nouveau
+cannot access any of the i2c external monitoring chips it may find. If you
+have one of those, temperature and/or fan management through Nouveau's HWMON
+interface is likely not to work. This document may then not cover your situation
+entirely.
+
+Temperature management
+--------------------
+
+Temperature is exposed under as a read-only HWMON attribute temp1_input.
+
+In order to protect the GPU from overheating, Nouveau supports 4 configurable
+temperature thresholds:
+
+ * Fan_boost: Fan speed is set to 100% when reaching this temperature;
+ * Downclock: The GPU will be downclocked to reduce its power dissipation;
+ * Critical: The GPU is put on hold to further lower power dissipation;
+ * Shutdown: Shut the computer down to protect your GPU.
+
+WARNING: Some of these thresholds may not be used by Nouveau depending
+on your chipset.
+
+The default value for these thresholds comes from the GPU's vbios. These
+thresholds can be configured thanks to the following HWMON attributes:
+
+ * Fan_boost: temp1_auto_point1_temp and temp1_auto_point1_temp_hyst;
+ * Downclock: temp1_max and temp1_max_hyst;
+ * Critical: temp1_crit and temp1_crit_hyst;
+ * Shutdown: temp1_emergency and temp1_emergency_hyst.
+
+NOTE: Remember that the values are stored as milli degrees Celsius. Don't forget
+to multiply!
+
+Fan management
+------------
+
+Not all cards have a drivable fan. If you do, then the following HWMON
+attributes should be available:
+
+ * pwm1_enable: Current fan management mode (NONE, MANUAL or AUTO);
+ * pwm1: Current PWM value (power percentage);
+ * pwm1_min: The minimum PWM speed allowed;
+ * pwm1_max: The maximum PWM speed allowed (bypassed when hitting Fan_boost);
+
+You may also have the following attribute:
+
+ * fan1_input: Speed in RPM of your fan.
+
+Your fan can be driven in different modes:
+
+ * 0: The fan is left untouched;
+ * 1: The fan can be driven in manual (use pwm1 to change the speed);
+ * 2; The fan is driven automatically depending on the temperature.
+
+NOTE: Be sure to use the manual mode if you want to drive the fan speed manually
+
+NOTE2: When operating in manual mode outside the vbios-defined
+[PWM_min, PWM_max] range, the reported fan speed (RPM) may not be accurate
+depending on your hardware.
+
+Bug reports
+---------
+
+Thermal management on Nouveau is new and may not work on all cards. If you have
+inquiries, please ping mupuf on IRC (#nouveau, freenode).
+
+Bug reports should be filled on Freedesktop's bug tracker. Please follow
+http://nouveau.freedesktop.org/wiki/Bugs
diff --git a/Documentation/thermal/power_allocator.txt b/Documentation/thermal/power_allocator.txt
new file mode 100644
index 000000000..a1ce2235f
--- /dev/null
+++ b/Documentation/thermal/power_allocator.txt
@@ -0,0 +1,247 @@
+Power allocator governor tunables
+=================================
+
+Trip points
+-----------
+
+The governor works optimally with the following two passive trip points:
+
+1.  "switch on" trip point: temperature above which the governor
+    control loop starts operating.  This is the first passive trip
+    point of the thermal zone.
+
+2.  "desired temperature" trip point: it should be higher than the
+    "switch on" trip point.  This the target temperature the governor
+    is controlling for.  This is the last passive trip point of the
+    thermal zone.
+
+PID Controller
+--------------
+
+The power allocator governor implements a
+Proportional-Integral-Derivative controller (PID controller) with
+temperature as the control input and power as the controlled output:
+
+    P_max = k_p * e + k_i * err_integral + k_d * diff_err + sustainable_power
+
+where
+    e = desired_temperature - current_temperature
+    err_integral is the sum of previous errors
+    diff_err = e - previous_error
+
+It is similar to the one depicted below:
+
+                                      k_d
+                                       |
+current_temp                           |
+     |                                 v
+     |                +----------+   +---+
+     |         +----->| diff_err |-->| X |------+
+     |         |      +----------+   +---+      |
+     |         |                                |      tdp        actor
+     |         |                      k_i       |       |  get_requested_power()
+     |         |                       |        |       |        |     |
+     |         |                       |        |       |        |     | ...
+     v         |                       v        v       v        v     v
+   +---+       |      +-------+      +---+    +---+   +---+   +----------+
+   | S |-------+----->| sum e |----->| X |--->| S |-->| S |-->|power     |
+   +---+       |      +-------+      +---+    +---+   +---+   |allocation|
+     ^         |                                ^             +----------+
+     |         |                                |                |     |
+     |         |        +---+                   |                |     |
+     |         +------->| X |-------------------+                v     v
+     |                  +---+                               granted performance
+desired_temperature       ^
+                          |
+                          |
+                      k_po/k_pu
+
+Sustainable power
+-----------------
+
+An estimate of the sustainable dissipatable power (in mW) should be
+provided while registering the thermal zone.  This estimates the
+sustained power that can be dissipated at the desired control
+temperature.  This is the maximum sustained power for allocation at
+the desired maximum temperature.  The actual sustained power can vary
+for a number of reasons.  The closed loop controller will take care of
+variations such as environmental conditions, and some factors related
+to the speed-grade of the silicon.  `sustainable_power` is therefore
+simply an estimate, and may be tuned to affect the aggressiveness of
+the thermal ramp. For reference, the sustainable power of a 4" phone
+is typically 2000mW, while on a 10" tablet is around 4500mW (may vary
+depending on screen size).
+
+If you are using device tree, do add it as a property of the
+thermal-zone.  For example:
+
+	thermal-zones {
+		soc_thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			sustainable-power = <2500>;
+			...
+
+Instead, if the thermal zone is registered from the platform code, pass a
+`thermal_zone_params` that has a `sustainable_power`.  If no
+`thermal_zone_params` were being passed, then something like below
+will suffice:
+
+	static const struct thermal_zone_params tz_params = {
+		.sustainable_power = 3500,
+	};
+
+and then pass `tz_params` as the 5th parameter to
+`thermal_zone_device_register()`
+
+k_po and k_pu
+-------------
+
+The implementation of the PID controller in the power allocator
+thermal governor allows the configuration of two proportional term
+constants: `k_po` and `k_pu`.  `k_po` is the proportional term
+constant during temperature overshoot periods (current temperature is
+above "desired temperature" trip point).  Conversely, `k_pu` is the
+proportional term constant during temperature undershoot periods
+(current temperature below "desired temperature" trip point).
+
+These controls are intended as the primary mechanism for configuring
+the permitted thermal "ramp" of the system.  For instance, a lower
+`k_pu` value will provide a slower ramp, at the cost of capping
+available capacity at a low temperature.  On the other hand, a high
+value of `k_pu` will result in the governor granting very high power
+whilst temperature is low, and may lead to temperature overshooting.
+
+The default value for `k_pu` is:
+
+    2 * sustainable_power / (desired_temperature - switch_on_temp)
+
+This means that at `switch_on_temp` the output of the controller's
+proportional term will be 2 * `sustainable_power`.  The default value
+for `k_po` is:
+
+    sustainable_power / (desired_temperature - switch_on_temp)
+
+Focusing on the proportional and feed forward values of the PID
+controller equation we have:
+
+    P_max = k_p * e + sustainable_power
+
+The proportional term is proportional to the difference between the
+desired temperature and the current one.  When the current temperature
+is the desired one, then the proportional component is zero and
+`P_max` = `sustainable_power`.  That is, the system should operate in
+thermal equilibrium under constant load.  `sustainable_power` is only
+an estimate, which is the reason for closed-loop control such as this.
+
+Expanding `k_pu` we get:
+    P_max = 2 * sustainable_power * (T_set - T) / (T_set - T_on) +
+        sustainable_power
+
+where
+    T_set is the desired temperature
+    T is the current temperature
+    T_on is the switch on temperature
+
+When the current temperature is the switch_on temperature, the above
+formula becomes:
+
+    P_max = 2 * sustainable_power * (T_set - T_on) / (T_set - T_on) +
+        sustainable_power = 2 * sustainable_power + sustainable_power =
+        3 * sustainable_power
+
+Therefore, the proportional term alone linearly decreases power from
+3 * `sustainable_power` to `sustainable_power` as the temperature
+rises from the switch on temperature to the desired temperature.
+
+k_i and integral_cutoff
+-----------------------
+
+`k_i` configures the PID loop's integral term constant.  This term
+allows the PID controller to compensate for long term drift and for
+the quantized nature of the output control: cooling devices can't set
+the exact power that the governor requests.  When the temperature
+error is below `integral_cutoff`, errors are accumulated in the
+integral term.  This term is then multiplied by `k_i` and the result
+added to the output of the controller.  Typically `k_i` is set low (1
+or 2) and `integral_cutoff` is 0.
+
+k_d
+---
+
+`k_d` configures the PID loop's derivative term constant.  It's
+recommended to leave it as the default: 0.
+
+Cooling device power API
+========================
+
+Cooling devices controlled by this governor must supply the additional
+"power" API in their `cooling_device_ops`.  It consists on three ops:
+
+1. int get_requested_power(struct thermal_cooling_device *cdev,
+	struct thermal_zone_device *tz, u32 *power);
+@cdev: The `struct thermal_cooling_device` pointer
+@tz: thermal zone in which we are currently operating
+@power: pointer in which to store the calculated power
+
+`get_requested_power()` calculates the power requested by the device
+in milliwatts and stores it in @power .  It should return 0 on
+success, -E* on failure.  This is currently used by the power
+allocator governor to calculate how much power to give to each cooling
+device.
+
+2. int state2power(struct thermal_cooling_device *cdev, struct
+        thermal_zone_device *tz, unsigned long state, u32 *power);
+@cdev: The `struct thermal_cooling_device` pointer
+@tz: thermal zone in which we are currently operating
+@state: A cooling device state
+@power: pointer in which to store the equivalent power
+
+Convert cooling device state @state into power consumption in
+milliwatts and store it in @power.  It should return 0 on success, -E*
+on failure.  This is currently used by thermal core to calculate the
+maximum power that an actor can consume.
+
+3. int power2state(struct thermal_cooling_device *cdev, u32 power,
+	unsigned long *state);
+@cdev: The `struct thermal_cooling_device` pointer
+@power: power in milliwatts
+@state: pointer in which to store the resulting state
+
+Calculate a cooling device state that would make the device consume at
+most @power mW and store it in @state.  It should return 0 on success,
+-E* on failure.  This is currently used by the thermal core to convert
+a given power set by the power allocator governor to a state that the
+cooling device can set.  It is a function because this conversion may
+depend on external factors that may change so this function should the
+best conversion given "current circumstances".
+
+Cooling device weights
+----------------------
+
+Weights are a mechanism to bias the allocation among cooling
+devices.  They express the relative power efficiency of different
+cooling devices.  Higher weight can be used to express higher power
+efficiency.  Weighting is relative such that if each cooling device
+has a weight of one they are considered equal.  This is particularly
+useful in heterogeneous systems where two cooling devices may perform
+the same kind of compute, but with different efficiency.  For example,
+a system with two different types of processors.
+
+If the thermal zone is registered using
+`thermal_zone_device_register()` (i.e., platform code), then weights
+are passed as part of the thermal zone's `thermal_bind_parameters`.
+If the platform is registered using device tree, then they are passed
+as the `contribution` property of each map in the `cooling-maps` node.
+
+Limitations of the power allocator governor
+===========================================
+
+The power allocator governor's PID controller works best if there is a
+periodic tick.  If you have a driver that calls
+`thermal_zone_device_update()` (or anything that ends up calling the
+governor's `throttle()` function) repetitively, the governor response
+won't be very good.  Note that this is not particular to this
+governor, step-wise will also misbehave if you call its throttle()
+faster than the normal thermal framework tick (due to interrupts for
+example) as it will overreact.
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
new file mode 100644
index 000000000..911399730
--- /dev/null
+++ b/Documentation/thermal/sysfs-api.txt
@@ -0,0 +1,636 @@
+Generic Thermal Sysfs driver How To
+===================================
+
+Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
+
+Updated: 2 January 2008
+
+Copyright (c)  2008 Intel Corporation
+
+
+0. Introduction
+
+The generic thermal sysfs provides a set of interfaces for thermal zone
+devices (sensors) and thermal cooling devices (fan, processor...) to register
+with the thermal management solution and to be a part of it.
+
+This how-to focuses on enabling new thermal zone and cooling devices to
+participate in thermal management.
+This solution is platform independent and any type of thermal zone devices
+and cooling devices should be able to make use of the infrastructure.
+
+The main task of the thermal sysfs driver is to expose thermal zone attributes
+as well as cooling device attributes to the user space.
+An intelligent thermal management application can make decisions based on
+inputs from thermal zone attributes (the current temperature and trip point
+temperature) and throttle appropriate devices.
+
+[0-*]	denotes any positive number starting from 0
+[1-*]	denotes any positive number starting from 1
+
+1. thermal sysfs driver interface functions
+
+1.1 thermal zone device interface
+1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *type,
+		int trips, int mask, void *devdata,
+		struct thermal_zone_device_ops *ops,
+		const struct thermal_zone_params *tzp,
+		int passive_delay, int polling_delay))
+
+    This interface function adds a new thermal zone device (sensor) to
+    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
+    thermal cooling devices registered at the same time.
+
+    type: the thermal zone type.
+    trips: the total number of trip points this thermal zone supports.
+    mask: Bit string: If 'n'th bit is set, then trip point 'n' is writeable.
+    devdata: device private data
+    ops: thermal zone device call-backs.
+	.bind: bind the thermal zone device with a thermal cooling device.
+	.unbind: unbind the thermal zone device with a thermal cooling device.
+	.get_temp: get the current temperature of the thermal zone.
+	.set_trips: set the trip points window. Whenever the current temperature
+		    is updated, the trip points immediately below and above the
+		    current temperature are found.
+	.get_mode: get the current mode (enabled/disabled) of the thermal zone.
+	    - "enabled" means the kernel thermal management is enabled.
+	    - "disabled" will prevent kernel thermal driver action upon trip points
+	      so that user applications can take charge of thermal management.
+	.set_mode: set the mode (enabled/disabled) of the thermal zone.
+	.get_trip_type: get the type of certain trip point.
+	.get_trip_temp: get the temperature above which the certain trip point
+			will be fired.
+	.set_emul_temp: set the emulation temperature which helps in debugging
+			different threshold temperature points.
+    tzp: thermal zone platform parameters.
+    passive_delay: number of milliseconds to wait between polls when
+	performing passive cooling.
+    polling_delay: number of milliseconds to wait between polls when checking
+	whether trip points have been crossed (0 for interrupt driven systems).
+
+
+1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
+
+    This interface function removes the thermal zone device.
+    It deletes the corresponding entry from /sys/class/thermal folder and
+    unbinds all the thermal cooling devices it uses.
+
+1.1.3 struct thermal_zone_device *thermal_zone_of_sensor_register(
+		struct device *dev, int sensor_id, void *data,
+		const struct thermal_zone_of_device_ops *ops)
+
+	This interface adds a new sensor to a DT thermal zone.
+	This function will search the list of thermal zones described in
+	device tree and look for the zone that refer to the sensor device
+	pointed by dev->of_node as temperature providers. For the zone
+	pointing to the sensor node, the sensor will be added to the DT
+	thermal zone device.
+
+	The parameters for this interface are:
+	dev:		Device node of sensor containing valid node pointer in
+			dev->of_node.
+	sensor_id:	a sensor identifier, in case the sensor IP has more
+			than one sensors
+	data:		a private pointer (owned by the caller) that will be
+			passed back, when a temperature reading is needed.
+	ops:		struct thermal_zone_of_device_ops *.
+
+			get_temp:	a pointer to a function that reads the
+					sensor temperature. This is mandatory
+					callback provided by sensor driver.
+			set_trips:      a pointer to a function that sets a
+					temperature window. When this window is
+					left the driver must inform the thermal
+					core via thermal_zone_device_update.
+			get_trend: 	a pointer to a function that reads the
+					sensor temperature trend.
+			set_emul_temp:	a pointer to a function that sets
+					sensor emulated temperature.
+	The thermal zone temperature is provided by the get_temp() function
+	pointer of thermal_zone_of_device_ops. When called, it will
+	have the private pointer @data back.
+
+	It returns error pointer if fails otherwise valid thermal zone device
+	handle. Caller should check the return handle with IS_ERR() for finding
+	whether success or not.
+
+1.1.4 void thermal_zone_of_sensor_unregister(struct device *dev,
+		struct thermal_zone_device *tzd)
+
+	This interface unregisters a sensor from a DT thermal zone which was
+	successfully added by interface thermal_zone_of_sensor_register().
+	This function removes the sensor callbacks and private data from the
+	thermal zone device registered with thermal_zone_of_sensor_register()
+	interface. It will also silent the zone by remove the .get_temp() and
+	get_trend() thermal zone device callbacks.
+
+1.1.5 struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
+		struct device *dev, int sensor_id,
+		void *data, const struct thermal_zone_of_device_ops *ops)
+
+	This interface is resource managed version of
+	thermal_zone_of_sensor_register().
+	All details of thermal_zone_of_sensor_register() described in
+	section 1.1.3 is applicable here.
+	The benefit of using this interface to register sensor is that it
+	is not require to explicitly call thermal_zone_of_sensor_unregister()
+	in error path or during driver unbinding as this is done by driver
+	resource manager.
+
+1.1.6 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
+		struct thermal_zone_device *tzd)
+
+	This interface is resource managed version of
+	thermal_zone_of_sensor_unregister().
+	All details of thermal_zone_of_sensor_unregister() described in
+	section 1.1.4 is applicable here.
+	Normally this function will not need to be called and the resource
+	management code will ensure that the resource is freed.
+
+1.1.7 int thermal_zone_get_slope(struct thermal_zone_device *tz)
+
+	This interface is used to read the slope attribute value
+	for the thermal zone device, which might be useful for platform
+	drivers for temperature calculations.
+
+1.1.8 int thermal_zone_get_offset(struct thermal_zone_device *tz)
+
+	This interface is used to read the offset attribute value
+	for the thermal zone device, which might be useful for platform
+	drivers for temperature calculations.
+
+1.2 thermal cooling device interface
+1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
+		void *devdata, struct thermal_cooling_device_ops *)
+
+    This interface function adds a new thermal cooling device (fan/processor/...)
+    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+    to all the thermal zone devices registered at the same time.
+    name: the cooling device name.
+    devdata: device private data.
+    ops: thermal cooling devices call-backs.
+	.get_max_state: get the Maximum throttle state of the cooling device.
+	.get_cur_state: get the Currently requested throttle state of the cooling device.
+	.set_cur_state: set the Current throttle state of the cooling device.
+
+1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
+
+    This interface function removes the thermal cooling device.
+    It deletes the corresponding entry from /sys/class/thermal folder and
+    unbinds itself from all the thermal zone devices using it.
+
+1.3 interface for binding a thermal zone device with a thermal cooling device
+1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
+	int trip, struct thermal_cooling_device *cdev,
+	unsigned long upper, unsigned long lower, unsigned int weight);
+
+    This interface function binds a thermal cooling device to a particular trip
+    point of a thermal zone device.
+    This function is usually called in the thermal zone device .bind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point in this thermal zone the cooling device
+          is associated with.
+    upper:the Maximum cooling state for this trip point.
+          THERMAL_NO_LIMIT means no upper limit,
+	  and the cooling device can be in max_state.
+    lower:the Minimum cooling state can be used for this trip point.
+          THERMAL_NO_LIMIT means no lower limit,
+	  and the cooling device can be in cooling state 0.
+    weight: the influence of this cooling device in this thermal
+            zone.  See 1.4.1 below for more information.
+
+1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
+		int trip, struct thermal_cooling_device *cdev);
+
+    This interface function unbinds a thermal cooling device from a particular
+    trip point of a thermal zone device. This function is usually called in
+    the thermal zone device .unbind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point in this thermal zone the cooling device
+          is associated with.
+
+1.4 Thermal Zone Parameters
+1.4.1 struct thermal_bind_params
+    This structure defines the following parameters that are used to bind
+    a zone with a cooling device for a particular trip point.
+    .cdev: The cooling device pointer
+    .weight: The 'influence' of a particular cooling device on this
+             zone. This is relative to the rest of the cooling
+             devices. For example, if all cooling devices have a
+             weight of 1, then they all contribute the same. You can
+             use percentages if you want, but it's not mandatory. A
+             weight of 0 means that this cooling device doesn't
+             contribute to the cooling of this zone unless all cooling
+             devices have a weight of 0. If all weights are 0, then
+             they all contribute the same.
+    .trip_mask:This is a bit mask that gives the binding relation between
+               this thermal zone and cdev, for a particular trip point.
+               If nth bit is set, then the cdev and thermal zone are bound
+               for trip point n.
+    .binding_limits: This is an array of cooling state limits. Must have
+                     exactly 2 * thermal_zone.number_of_trip_points. It is an
+                     array consisting of tuples <lower-state upper-state> of
+                     state limits. Each trip will be associated with one state
+                     limit tuple when binding. A NULL pointer means
+                     <THERMAL_NO_LIMITS THERMAL_NO_LIMITS> on all trips.
+                     These limits are used when binding a cdev to a trip point.
+    .match: This call back returns success(0) if the 'tz and cdev' need to
+	    be bound, as per platform data.
+1.4.2 struct thermal_zone_params
+    This structure defines the platform level parameters for a thermal zone.
+    This data, for each thermal zone should come from the platform layer.
+    This is an optional feature where some platforms can choose not to
+    provide this data.
+    .governor_name: Name of the thermal governor used for this zone
+    .no_hwmon: a boolean to indicate if the thermal to hwmon sysfs interface
+               is required. when no_hwmon == false, a hwmon sysfs interface
+               will be created. when no_hwmon == true, nothing will be done.
+               In case the thermal_zone_params is NULL, the hwmon interface
+               will be created (for backward compatibility).
+    .num_tbps: Number of thermal_bind_params entries for this zone
+    .tbp: thermal_bind_params entries
+
+2. sysfs attributes structure
+
+RO	read only value
+WO	write only value
+RW	read/write value
+
+Thermal sysfs attributes will be represented under /sys/class/thermal.
+Hwmon sysfs I/F extension is also available under /sys/class/hwmon
+if hwmon is compiled in or built as a module.
+
+Thermal zone device sys I/F, created once it's registered:
+/sys/class/thermal/thermal_zone[0-*]:
+    |---type:			Type of the thermal zone
+    |---temp:			Current temperature
+    |---mode:			Working mode of the thermal zone
+    |---policy:			Thermal governor used for this zone
+    |---available_policies:	Available thermal governors for this zone
+    |---trip_point_[0-*]_temp:	Trip point temperature
+    |---trip_point_[0-*]_type:	Trip point type
+    |---trip_point_[0-*]_hyst:	Hysteresis value for this trip point
+    |---emul_temp:		Emulated temperature set node
+    |---sustainable_power:      Sustainable dissipatable power
+    |---k_po:                   Proportional term during temperature overshoot
+    |---k_pu:                   Proportional term during temperature undershoot
+    |---k_i:                    PID's integral term in the power allocator gov
+    |---k_d:                    PID's derivative term in the power allocator
+    |---integral_cutoff:        Offset above which errors are accumulated
+    |---slope:                  Slope constant applied as linear extrapolation
+    |---offset:                 Offset constant applied as linear extrapolation
+
+Thermal cooling device sys I/F, created once it's registered:
+/sys/class/thermal/cooling_device[0-*]:
+    |---type:			Type of the cooling device(processor/fan/...)
+    |---max_state:		Maximum cooling state of the cooling device
+    |---cur_state:		Current cooling state of the cooling device
+    |---stats:			Directory containing cooling device's statistics
+    |---stats/reset:		Writing any value resets the statistics
+    |---stats/time_in_state_ms:	Time (msec) spent in various cooling states
+    |---stats/total_trans:	Total number of times cooling state is changed
+    |---stats/trans_table:	Cooing state transition table
+
+
+Then next two dynamic attributes are created/removed in pairs. They represent
+the relationship between a thermal zone and its associated cooling device.
+They are created/removed for each successful execution of
+thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
+
+/sys/class/thermal/thermal_zone[0-*]:
+    |---cdev[0-*]:		[0-*]th cooling device in current thermal zone
+    |---cdev[0-*]_trip_point:	Trip point that cdev[0-*] is associated with
+    |---cdev[0-*]_weight:       Influence of the cooling device in
+                                this thermal zone
+
+Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
+the generic thermal driver also creates a hwmon sysfs I/F for each _type_
+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.
+
+/sys/class/hwmon/hwmon[0-*]:
+    |---name:			The type of the thermal zone devices
+    |---temp[1-*]_input:	The current temperature of thermal zone [1-*]
+    |---temp[1-*]_critical:	The critical trip point of thermal zone [1-*]
+
+Please read Documentation/hwmon/sysfs-interface 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
+
+passive
+	Attribute is only present for zones in which the passive cooling
+	policy is not supported by native thermal driver. Default is zero
+	and can be set to a temperature (in millidegrees) to enable a
+	passive trip point for the zone. Activation is done by polling with
+	an interval of 1 second.
+	Unit: millidegrees Celsius
+	Valid values: 0 (disabled) or greater than 1000
+	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/thermal/power_allocator.txt
+	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/thermal/power_allocator.txt
+	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/thermal/power_allocator.txt
+	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/thermal/power_allocator.txt
+	RW, Optional
+
+k_d
+	The derivative term of the power allocator governor's PID
+	controller. For more information see
+	Documentation/thermal/power_allocator.txt
+	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/thermal/power_allocator.txt
+	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.  usertime
+	units here is 10mS (similar to other time exported in /proc).
+	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
+
+ACPI thermal zone may support multiple trip points like critical, hot,
+passive, active. If an ACPI thermal zone supports critical, passive,
+active[0] and active[1] at the same time, it may register itself as a
+thermal_zone_device (thermal_zone1) with 4 trip points in all.
+It has one processor and one fan, which are both registered as
+thermal_cooling_device. Both are considered to have the same
+effectiveness in cooling the thermal zone.
+
+If the processor is listed in _PSL method, and the fan is listed in _AL0
+method, the sys I/F structure will be built like this:
+
+/sys/class/thermal:
+
+|thermal_zone1:
+    |---type:			acpitz
+    |---temp:			37000
+    |---mode:			enabled
+    |---policy:			step_wise
+    |---available_policies:	step_wise fair_share
+    |---trip_point_0_temp:	100000
+    |---trip_point_0_type:	critical
+    |---trip_point_1_temp:	80000
+    |---trip_point_1_type:	passive
+    |---trip_point_2_temp:	70000
+    |---trip_point_2_type:	active0
+    |---trip_point_3_temp:	60000
+    |---trip_point_3_type:	active1
+    |---cdev0:			--->/sys/class/thermal/cooling_device0
+    |---cdev0_trip_point:	1	/* cdev0 can be used for passive */
+    |---cdev0_weight:           1024
+    |---cdev1:			--->/sys/class/thermal/cooling_device3
+    |---cdev1_trip_point:	2	/* cdev1 can be used for active[0]*/
+    |---cdev1_weight:           1024
+
+|cooling_device0:
+    |---type:			Processor
+    |---max_state:		8
+    |---cur_state:		0
+
+|cooling_device3:
+    |---type:			Fan
+    |---max_state:		2
+    |---cur_state:		0
+
+/sys/class/hwmon:
+
+|hwmon0:
+    |---name:			acpitz
+    |---temp1_input:		37000
+    |---temp1_crit:		100000
+
+4. Event Notification
+
+The framework includes a simple notification mechanism, in the form of a
+netlink event. Netlink socket initialization is done during the _init_
+of the framework. Drivers which intend to use the notification mechanism
+just need to call thermal_generate_netlink_event() with two arguments viz
+(originator, event). The originator is a pointer to struct thermal_zone_device
+from where the event has been originated. An integer which represents the
+thermal zone device will be used in the message to identify the zone. The
+event will be one of:{THERMAL_AUX0, THERMAL_AUX1, THERMAL_CRITICAL,
+THERMAL_DEV_FAULT}. Notification can be sent when the current temperature
+crosses any of the configured thresholds.
+
+5. Export Symbol APIs:
+
+5.1: get_tz_trend:
+This function returns the trend of a thermal zone, i.e the rate of change
+of temperature of the thermal zone. Ideally, the thermal sensor drivers
+are supposed to implement the callback. If they don't, the thermal
+framework calculated the trend by comparing the previous and the current
+temperature values.
+
+5.2:get_thermal_instance:
+This function returns the thermal_instance corresponding to a given
+{thermal_zone, cooling_device, trip_point} combination. Returns NULL
+if such an instance does not exist.
+
+5.3:thermal_notify_framework:
+This function handles the trip events from sensor drivers. It starts
+throttling the cooling devices according to the policy configured.
+For CRITICAL and HOT trip points, this notifies the respective drivers,
+and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
+The throttling policy is based on the configured platform data; if no
+platform data is provided, this uses the step_wise throttling policy.
+
+5.4:thermal_cdev_update:
+This function serves as an arbitrator to set the state of a cooling
+device. It sets the cooling device to the deepest cooling state if
+possible.
+
+6. thermal_emergency_poweroff:
+
+On an event of critical trip temperature crossing. Thermal framework
+allows the system to shutdown gracefully by calling orderly_poweroff().
+In the event of a failure of orderly_poweroff() to shut down the system
+we are in danger of keeping the system alive at undesirably high
+temperatures. To mitigate this high risk scenario we program a work
+queue to fire after a pre-determined number of seconds to start
+an emergency shutdown of the device using the kernel_power_off()
+function. In case kernel_power_off() fails then finally
+emergency_restart() is called in the worst case.
+
+The delay should be carefully profiled so as to give adequate time for
+orderly_poweroff(). In case of failure of an orderly_poweroff() the
+emergency poweroff kicks in after the delay has elapsed and shuts down
+the system.
+
+If set to 0 emergency poweroff will not be supported. So a carefully
+profiled non-zero positive value is a must for emergerncy poweroff to be
+triggered.
diff --git a/Documentation/thermal/x86_pkg_temperature_thermal b/Documentation/thermal/x86_pkg_temperature_thermal
new file mode 100644
index 000000000..17a3a4c0a
--- /dev/null
+++ b/Documentation/thermal/x86_pkg_temperature_thermal
@@ -0,0 +1,47 @@
+Kernel driver: x86_pkg_temp_thermal
+===================
+
+Supported chips:
+* x86: with package level thermal management
+(Verify using: CPUID.06H:EAX[bit 6] =1)
+
+Authors: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
+
+Reference
+---
+Intel® 64 and IA-32 Architectures Software Developer’s Manual (Jan, 2013):
+Chapter 14.6: PACKAGE LEVEL THERMAL MANAGEMENT
+
+Description
+---------
+
+This driver register CPU digital temperature package level sensor as a thermal
+zone with maximum two user mode configurable trip points. Number of trip points
+depends on the capability of the package. Once the trip point is violated,
+user mode can receive notification via thermal notification mechanism and can
+take any action to control temperature.
+
+
+Threshold management
+--------------------
+Each package will register as a thermal zone under /sys/class/thermal.
+Example:
+/sys/class/thermal/thermal_zone1
+
+This contains two trip points:
+- trip_point_0_temp
+- trip_point_1_temp
+
+User can set any temperature between 0 to TJ-Max temperature. Temperature units
+are in milli-degree Celsius. Refer to "Documentation/thermal/sysfs-api.txt" for
+thermal sys-fs details.
+
+Any value other than 0 in these trip points, can trigger thermal notifications.
+Setting 0, stops sending thermal notifications.
+
+Thermal notifications: To get kobject-uevent notifications, set the thermal zone
+policy to "user_space". For example: echo -n "user_space" > policy
+
+
+
+