Documentation: hwmon: coretemp: Update supported CPUs and TjMax values

Update the coretemp documentation to reflect current driver capabilities:

- Extend the supported CPU model list to include Atom processors from
  Bonnell through Jasper Lake, maintaining the original format with
  model numbers and adding X86_FEATURE_DTHERM as the actual detection
  mechanism. Added models: 0x37 (Bay Trail), 0x4a (Merrifield),
  0x4c (Cherry Trail), 0x5a (Moorefield), 0x5c (Apollo Lake),
  0x7a (Gemini Lake), 0x96 (Elkhart Lake), 0x9c (Jasper Lake)

- Update the description to note that per-package temperature sensing
  is available on Sandy Bridge and all newer processors

- Clarify that TjMax is read from MSR_IA32_TEMPERATURE_TARGET on modern
  CPUs (Nehalem and newer)

- Add TjMax values for newer Atom processor families to Appendix A:
  - 22nm Silvermont/Bay Trail: E38xx at 110C, Z37xx at 90C
  - 22nm Silvermont/Moorefield: Z35xx at 90C
  - 14nm Airmont/Cherry Trail: Z8xxx at 90C
  - 14nm Goldmont/Apollo Lake: 105C
  - 14nm Goldmont Plus/Gemini Lake: 105C
  - 10nm Tremont/Elkhart Lake: 105C
  - 10nm Tremont/Jasper Lake: 105C

TjMax values obtained from Intel ARK and official datasheets:
- E3845: https://www.intel.com/content/www/us/en/products/sku/78475/intel-atom-processor-e3845-2m-cache-1-91-ghz/specifications.html
- Z3600/Z3700: https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-z36xxx-z37xxx-datasheet-vol-1.pdf

Signed-off-by: Laveesh Bansal <laveeshb@laveeshbansal.com>
Link: https://lore.kernel.org/r/20260106155426.547872-2-laveeshb@laveeshbansal.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Laveesh Bansal 2026-01-06 15:54:25 +00:00 committed by Guenter Roeck
parent 75cf411b02
commit f6702aa05a

View file

@ -2,17 +2,21 @@ Kernel driver coretemp
======================
Supported chips:
* All Intel Core family
* All Intel Core family and Atom processors with Digital Thermal Sensor (DTS)
Prefix: 'coretemp'
CPUID: family 0x6, models
CPUID: family 0x6, models with X86_FEATURE_DTHERM, including:
- 0xe (Pentium M DC), 0xf (Core 2 DC 65nm),
- 0x16 (Core 2 SC 65nm), 0x17 (Penryn 45nm),
- 0x1a (Nehalem), 0x1c (Atom), 0x1e (Lynnfield),
- 0x26 (Tunnel Creek Atom), 0x27 (Medfield Atom),
- 0x36 (Cedar Trail Atom)
- 0x36 (Cedar Trail Atom), 0x37 (Bay Trail Atom),
- 0x4a (Merrifield Atom), 0x4c (Cherry Trail Atom),
- 0x5a (Moorefield Atom), 0x5c (Apollo Lake Atom),
- 0x7a (Gemini Lake Atom),
- 0x96 (Elkhart Lake Atom), 0x9c (Jasper Lake Atom)
Datasheet:
@ -28,9 +32,9 @@ Description
This driver permits reading the DTS (Digital Temperature Sensor) embedded
inside Intel CPUs. This driver can read both the per-core and per-package
temperature using the appropriate sensors. The per-package sensor is new;
as of now, it is present only in the SandyBridge platform. The driver will
show the temperature of all cores inside a package under a single device
temperature using the appropriate sensors. The per-package sensor is
available on Sandy Bridge and all newer processors. The driver will show
the temperature of all cores inside a package under a single device
directory inside hwmon.
Temperature is measured in degrees Celsius and measurement resolution is
@ -56,10 +60,11 @@ tempX_label Contains string "Core X", where X is processor
where Y is the package number.
================= ========================================================
On CPU models which support it, TjMax is read from a model-specific register.
On other models, it is set to an arbitrary value based on weak heuristics.
If these heuristics don't work for you, you can pass the correct TjMax value
as a module parameter (tjmax).
On modern CPUs (Nehalem and newer), TjMax is read from the
MSR_IA32_TEMPERATURE_TARGET register. On older models without this MSR,
TjMax is determined using lookup tables or heuristics. If these don't work
for your CPU, you can pass the correct TjMax value as a module parameter
(tjmax).
Appendix A. Known TjMax lists (TBD):
Some information comes from ark.intel.com
@ -100,6 +105,40 @@ Process Processor TjMax(C)
D2700/2550/2500 100
N2850/2800/2650/2600 100
22nm Atom Processors (Silvermont/Bay Trail)
E3845/3827/3826/3825/3815/3805 110
Z3795/3775/3770/3740/3736/3735/3680 90
22nm Atom Processors (Silvermont/Moorefield)
Z3580/3570/3560/3530 90
14nm Atom Processors (Airmont/Cherry Trail)
x5-Z8550/Z8500/Z8350/Z8330/Z8300 90
x7-Z8750/Z8700 90
14nm Atom Processors (Goldmont/Apollo Lake)
x5-E3940/E3930 105
x7-E3950 105
14nm Celeron/Pentium Processors
(Goldmont/Apollo Lake)
J3455/J3355 105
N3450/N3350 105
N4200 105
14nm Celeron/Pentium Processors
(Goldmont Plus/Gemini Lake)
J4105/J4005 105
N4100/N4000 105
N5000 105
10nm Atom Processors (Tremont/Elkhart Lake)
x6000E 105
10nm Celeron/Pentium Processors
(Tremont/Jasper Lake)
N4500/N5100/N6000 series 105
45nm Xeon Processors 5400 Quad-Core
X5492, X5482, X5472, X5470, X5460, X5450 85
E5472, E5462, E5450/40/30/20/10/05 85