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author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-26 09:51:16 -0300 |
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committer | Jonathan Corbet <corbet@lwn.net> | 2019-07-31 13:25:27 -0600 |
commit | ccf988b66d697efcd0ceccc2398e0d9b909cd17c (patch) | |
tree | 94022b812a20419675e4cac5af1540d75523d31d /Documentation/i2c/busses/i2c-i801 | |
parent | 09f4c750a8c7d1fc0b7bb3a7aa1de55de897a375 (diff) | |
download | linux-ccf988b66d697efcd0ceccc2398e0d9b909cd17c.tar.bz2 |
docs: i2c: convert to ReST and add to driver-api bookset
Convert each file at I2C subsystem, renaming them to .rst and
adding to the driver-api book.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/i2c/busses/i2c-i801')
-rw-r--r-- | Documentation/i2c/busses/i2c-i801 | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801 deleted file mode 100644 index f426c13c63a9..000000000000 --- a/Documentation/i2c/busses/i2c-i801 +++ /dev/null @@ -1,173 +0,0 @@ -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 Avoton (SOC) - * Intel Wellsburg (PCH) - * Intel Coleto Creek (PCH) - * Intel Wildcat Point (PCH) - * Intel BayTrail (SOC) - * Intel Braswell (SOC) - * Intel Sunrise Point (PCH) - * Intel Kaby Lake (PCH) - * Intel DNV (SOC) - * Intel Broxton (SOC) - * Intel Lewisburg (PCH) - * Intel Gemini Lake (SOC) - * Intel Cannon Lake (PCH) - * Intel Cedar Fork (PCH) - * Intel Ice Lake (PCH) - * Intel Comet Lake (PCH) - * Intel Elkhart Lake (PCH) - * Intel Tiger Lake (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 - 0x20 disable SMBus Host Notify - - -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 --------------------- - -Block process call is supported on the 82801EB (ICH5) and later chips. - - -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-scmi" ACPI driver. It could be that the -SMBus was hidden on purpose because it'll be driven by ACPI. If the -i2c-scmi driver works for you, just forget about the i2c-i801 driver and -don't try to unhide the ICH SMBus. Even if i2c-scmi 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 /sys/class/thermal. If you -find a thermal zone with type "acpitz", 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. |