168 lines
6.0 KiB
Plaintext
168 lines
6.0 KiB
Plaintext
Kernel driver i2c-i801
|
|
|
|
Supported adapters:
|
|
* Intel 82801AA and 82801AB (ICH and ICH0 - part of the
|
|
'810' and '810E' chipsets)
|
|
* Intel 82801BA (ICH2 - part of the '815E' chipset)
|
|
* Intel 82801CA/CAM (ICH3)
|
|
* Intel 82801DB (ICH4) (HW PEC supported)
|
|
* Intel 82801EB/ER (ICH5) (HW PEC supported)
|
|
* Intel 6300ESB
|
|
* Intel 82801FB/FR/FW/FRW (ICH6)
|
|
* Intel 82801G (ICH7)
|
|
* Intel 631xESB/632xESB (ESB2)
|
|
* Intel 82801H (ICH8)
|
|
* Intel 82801I (ICH9)
|
|
* Intel EP80579 (Tolapai)
|
|
* Intel 82801JI (ICH10)
|
|
* Intel 5/3400 Series (PCH)
|
|
* Intel 6 Series (PCH)
|
|
* Intel Patsburg (PCH)
|
|
* Intel DH89xxCC (PCH)
|
|
* Intel Panther Point (PCH)
|
|
* Intel Lynx Point (PCH)
|
|
* Intel Lynx Point-LP (PCH)
|
|
* Intel Avoton (SOC)
|
|
* Intel Wellsburg (PCH)
|
|
* Intel Coleto Creek (PCH)
|
|
* Intel Wildcat Point (PCH)
|
|
* Intel Wildcat Point-LP (PCH)
|
|
* Intel BayTrail (SOC)
|
|
* Intel Sunrise Point-H (PCH)
|
|
* Intel Sunrise Point-LP (PCH)
|
|
* Intel DNV (SOC)
|
|
* Intel Broxton (SOC)
|
|
* Intel Lewisburg (PCH)
|
|
Datasheets: Publicly available at the Intel website
|
|
|
|
On Intel Patsburg and later chipsets, both the normal host SMBus controller
|
|
and the additional 'Integrated Device Function' controllers are supported.
|
|
|
|
Authors:
|
|
Mark Studebaker <mdsxyz123@yahoo.com>
|
|
Jean Delvare <jdelvare@suse.de>
|
|
|
|
|
|
Module Parameters
|
|
-----------------
|
|
|
|
* disable_features (bit vector)
|
|
Disable selected features normally supported by the device. This makes it
|
|
possible to work around possible driver or hardware bugs if the feature in
|
|
question doesn't work as intended for whatever reason. Bit values:
|
|
0x01 disable SMBus PEC
|
|
0x02 disable the block buffer
|
|
0x08 disable the I2C block read functionality
|
|
0x10 don't use interrupts
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
The ICH (properly known as the 82801AA), ICH0 (82801AB), ICH2 (82801BA),
|
|
ICH3 (82801CA/CAM) and later devices (PCH) are Intel chips that are a part of
|
|
Intel's '810' chipset for Celeron-based PCs, '810E' chipset for
|
|
Pentium-based PCs, '815E' chipset, and others.
|
|
|
|
The ICH chips contain at least SEVEN separate PCI functions in TWO logical
|
|
PCI devices. An output of lspci will show something similar to the
|
|
following:
|
|
|
|
00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01)
|
|
00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01)
|
|
00:1f.1 IDE interface: Intel Corporation: Unknown device 2411 (rev 01)
|
|
00:1f.2 USB Controller: Intel Corporation: Unknown device 2412 (rev 01)
|
|
00:1f.3 Unknown class [0c05]: Intel Corporation: Unknown device 2413 (rev 01)
|
|
|
|
The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial
|
|
Controller.
|
|
|
|
The ICH chips are quite similar to Intel's PIIX4 chip, at least in the
|
|
SMBus controller.
|
|
|
|
|
|
Process Call Support
|
|
--------------------
|
|
|
|
Not supported.
|
|
|
|
|
|
I2C Block Read Support
|
|
----------------------
|
|
|
|
I2C block read is supported on the 82801EB (ICH5) and later chips.
|
|
|
|
|
|
SMBus 2.0 Support
|
|
-----------------
|
|
|
|
The 82801DB (ICH4) and later chips support several SMBus 2.0 features.
|
|
|
|
|
|
Interrupt Support
|
|
-----------------
|
|
|
|
PCI interrupt support is supported on the 82801EB (ICH5) and later chips.
|
|
|
|
|
|
Hidden ICH SMBus
|
|
----------------
|
|
|
|
If your system has an Intel ICH south bridge, but you do NOT see the
|
|
SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the
|
|
BIOS to enable it, it means it has been hidden by the BIOS code. Asus is
|
|
well known for first doing this on their P4B motherboard, and many other
|
|
boards after that. Some vendor machines are affected as well.
|
|
|
|
The first thing to try is the "i2c_ec" ACPI driver. It could be that the
|
|
SMBus was hidden on purpose because it'll be driven by ACPI. If the
|
|
i2c_ec driver works for you, just forget about the i2c-i801 driver and
|
|
don't try to unhide the ICH SMBus. Even if i2c_ec doesn't work, you
|
|
better make sure that the SMBus isn't used by the ACPI code. Try loading
|
|
the "fan" and "thermal" drivers, and check in /proc/acpi/fan and
|
|
/proc/acpi/thermal_zone. If you find anything there, it's likely that
|
|
the ACPI is accessing the SMBus and it's safer not to unhide it. Only
|
|
once you are certain that ACPI isn't using the SMBus, you can attempt
|
|
to unhide it.
|
|
|
|
In order to unhide the SMBus, we need to change the value of a PCI
|
|
register before the kernel enumerates the PCI devices. This is done in
|
|
drivers/pci/quirks.c, where all affected boards must be listed (see
|
|
function asus_hides_smbus_hostbridge.) If the SMBus device is missing,
|
|
and you think there's something interesting on the SMBus (e.g. a
|
|
hardware monitoring chip), you need to add your board to the list.
|
|
|
|
The motherboard is identified using the subvendor and subdevice IDs of the
|
|
host bridge PCI device. Get yours with "lspci -n -v -s 00:00.0":
|
|
|
|
00:00.0 Class 0600: 8086:2570 (rev 02)
|
|
Subsystem: 1043:80f2
|
|
Flags: bus master, fast devsel, latency 0
|
|
Memory at fc000000 (32-bit, prefetchable) [size=32M]
|
|
Capabilities: [e4] #09 [2106]
|
|
Capabilities: [a0] AGP version 3.0
|
|
|
|
Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043
|
|
(Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic
|
|
names for the bridge ID and the subvendor ID in include/linux/pci_ids.h,
|
|
and then add a case for your subdevice ID at the right place in
|
|
drivers/pci/quirks.c. Then please give it very good testing, to make sure
|
|
that the unhidden SMBus doesn't conflict with e.g. ACPI.
|
|
|
|
If it works, proves useful (i.e. there are usable chips on the SMBus)
|
|
and seems safe, please submit a patch for inclusion into the kernel.
|
|
|
|
Note: There's a useful script in lm_sensors 2.10.2 and later, named
|
|
unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to
|
|
temporarily unhide the SMBus without having to patch and recompile your
|
|
kernel. It's very convenient if you just want to check if there's
|
|
anything interesting on your hidden ICH SMBus.
|
|
|
|
|
|
**********************
|
|
The lm_sensors project gratefully acknowledges the support of Texas
|
|
Instruments in the initial development of this driver.
|
|
|
|
The lm_sensors project gratefully acknowledges the support of Intel in the
|
|
development of SMBus 2.0 / ICH4 features of this driver.
|