From 60eb0b35a9cc3400251cb4028d100e350649cf8a Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Fri, 24 Nov 2006 11:47:08 -0200 Subject: ACPI: ibm-acpi: Implement direct-ec-access thermal reading modes for up to 16 sensors This patch extends ibm-acpi to support reading thermal sensors directly through ACPI EC register access. It uses a DMI match to detect ThinkPads with a new-style embedded controller, that are known to have forward- compatible register maps and use 0x00 to fill in non-used registers and export thermal sensors at EC offsets 0x78-7F and 0xC0-C7. Direct ACPI EC register access is implemented for 8-sensor and 16-sensor new-style ThinkPad controller firmwares as an experimental feature. The code does some limited sanity checks on the temperatures read through EC access, and will default to the old ACPI TMP0-7 mode if anything is amiss. Userspace ABI is not changed for 8 sensors, but /proc/acpi/ibm/thermal is extended for 16 sensors if the firmware supports 16 sensors. A documentation update is also provided. The information about the ThinkPad register map was determined by studying ibm-acpi "ecdump" output from various ThinkPad models, submitted by subscribers of the linux-thinkpad mailinglist. Futher information was gathered from the DSDT tables, as they describe the EC register map in recent ThinkPads. DSDT source shows that TMP0-7 access and direct register access are actually the same thing on these firmwares, but unfortunately IBM never did update their DSDT EC register map to export TMP8-TMP15 for the second range of sensors. Signed-off-by: Henrique de Moraes Holschuh --- Documentation/ibm-acpi.txt | 55 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 12 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ibm-acpi.txt b/Documentation/ibm-acpi.txt index e50595bfd8ea..30f09e7a423e 100644 --- a/Documentation/ibm-acpi.txt +++ b/Documentation/ibm-acpi.txt @@ -398,25 +398,56 @@ Temperature sensors -- /proc/acpi/ibm/thermal Most ThinkPads include six or more separate temperature sensors but only expose the CPU temperature through the standard ACPI methods. -This feature shows readings from up to eight different sensors. Some -readings may not be valid, e.g. may show large negative values. For -example, on the X40, a typical output may be: +This feature shows readings from up to eight different sensors on older +ThinkPads, and it has experimental support for up to sixteen different +sensors on newer ThinkPads. Readings from sensors that are not available +return -128. +No commands can be written to this file. + +EXPERIMENTAL: The 16-sensors feature is marked EXPERIMENTAL because the +implementation directly accesses hardware registers and may not work as +expected. USE WITH CAUTION! To use this feature, you need to supply the +experimental=1 parameter when loading the module. When EXPERIMENTAL +mode is enabled, reading the first 8 sensors on newer ThinkPads will +also use an new experimental thermal sensor access mode. + +For example, on the X40, a typical output may be: temperatures: 42 42 45 41 36 -128 33 -128 -Thomas Gruber took his R51 apart and traced all six active sensors in -his laptop (the location of sensors may vary on other models): +EXPERIMENTAL: On the T43/p, a typical output may be: +temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 + +The mapping of thermal sensors to physical locations varies depending on +system-board model (and thus, on ThinkPad model). + +http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that +tries to track down these locations for various models. + +Most (newer?) models seem to follow this pattern: 1: CPU -2: Mini PCI Module -3: HDD +2: (depends on model) +3: (depends on model) 4: GPU -5: Battery -6: N/A -7: Battery -8: N/A +5: Main battery: main sensor +6: Bay battery: main sensor +7: Main battery: secondary sensor +8: Bay battery: secondary sensor +9-15: (depends on model) + +For the R51 (source: Thomas Gruber): +2: Mini-PCI +3: Internal HDD + +For the T43, T43/p (source: Shmidoax/Thinkwiki.org) +http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p +2: System board, left side (near PCMCIA slot), reported as HDAPS temp +3: PCMCIA slot +9: MCH (northbridge) to DRAM Bus +10: ICH (southbridge), under Mini-PCI card, under touchpad +11: Power regulator, underside of system board, below F2 key -No commands can be written to this file. EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump ------------------------------------------------------------------------ -- cgit v1.2.3