Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Kernel driver i2c-i801 2 3 Supported adapters: 4 * Intel 82801AA and 82801AB (ICH and ICH0 - part of the 5 '810' and '810E' chipsets) 6 * Intel 82801BA (ICH2 - part of the '815E' chipset) 7 * Intel 82801CA/CAM (ICH3) 8 * Intel 82801DB (ICH4) (HW PEC supported) 9 * Intel 82801EB/ER (ICH5) (HW PEC supported) 10 * Intel 6300ESB 11 * Intel 82801FB/FR/FW/FRW (ICH6) 12 * Intel 82801G (ICH7) 13 * Intel 631xESB/632xESB (ESB2) 14 * Intel 82801H (ICH8) 15 * Intel 82801I (ICH9) 16 * Intel EP80579 (Tolapai) 17 * Intel 82801JI (ICH10) 18 * Intel 5/3400 Series (PCH) 19 * Intel 6 Series (PCH) 20 * Intel Patsburg (PCH) 21 * Intel DH89xxCC (PCH) 22 * Intel Panther Point (PCH) 23 * Intel Lynx Point (PCH) 24 * Intel Lynx Point-LP (PCH) 25 * Intel Avoton (SOC) 26 * Intel Wellsburg (PCH) 27 * Intel Coleto Creek (PCH) 28 * Intel Wildcat Point (PCH) 29 * Intel Wildcat Point-LP (PCH) 30 * Intel BayTrail (SOC) 31 * Intel Braswell (SOC) 32 * Intel Sunrise Point-H (PCH) 33 * Intel Sunrise Point-LP (PCH) 34 * Intel Kaby Lake-H (PCH) 35 * Intel DNV (SOC) 36 * Intel Broxton (SOC) 37 * Intel Lewisburg (PCH) 38 * Intel Gemini Lake (SOC) 39 * Intel Cannon Lake-H (PCH) 40 * Intel Cannon Lake-LP (PCH) 41 * Intel Cedar Fork (PCH) 42 Datasheets: Publicly available at the Intel website 43 44 On Intel Patsburg and later chipsets, both the normal host SMBus controller 45 and the additional 'Integrated Device Function' controllers are supported. 46 47 Authors: 48 Mark Studebaker <mdsxyz123@yahoo.com> 49 Jean Delvare <jdelvare@suse.de> 50 51 52 Module Parameters 53 ----------------- 54 55 * disable_features (bit vector) 56 Disable selected features normally supported by the device. This makes it 57 possible to work around possible driver or hardware bugs if the feature in 58 question doesn't work as intended for whatever reason. Bit values: 59 0x01 disable SMBus PEC 60 0x02 disable the block buffer 61 0x08 disable the I2C block read functionality 62 0x10 don't use interrupts 63 64 65 Description 66 ----------- 67 68 The ICH (properly known as the 82801AA), ICH0 (82801AB), ICH2 (82801BA), 69 ICH3 (82801CA/CAM) and later devices (PCH) are Intel chips that are a part of 70 Intel's '810' chipset for Celeron-based PCs, '810E' chipset for 71 Pentium-based PCs, '815E' chipset, and others. 72 73 The ICH chips contain at least SEVEN separate PCI functions in TWO logical 74 PCI devices. An output of lspci will show something similar to the 75 following: 76 77 00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01) 78 00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01) 79 00:1f.1 IDE interface: Intel Corporation: Unknown device 2411 (rev 01) 80 00:1f.2 USB Controller: Intel Corporation: Unknown device 2412 (rev 01) 81 00:1f.3 Unknown class [0c05]: Intel Corporation: Unknown device 2413 (rev 01) 82 83 The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial 84 Controller. 85 86 The ICH chips are quite similar to Intel's PIIX4 chip, at least in the 87 SMBus controller. 88 89 90 Process Call Support 91 -------------------- 92 93 Not supported. 94 95 96 I2C Block Read Support 97 ---------------------- 98 99 I2C block read is supported on the 82801EB (ICH5) and later chips. 100 101 102 SMBus 2.0 Support 103 ----------------- 104 105 The 82801DB (ICH4) and later chips support several SMBus 2.0 features. 106 107 108 Interrupt Support 109 ----------------- 110 111 PCI interrupt support is supported on the 82801EB (ICH5) and later chips. 112 113 114 Hidden ICH SMBus 115 ---------------- 116 117 If your system has an Intel ICH south bridge, but you do NOT see the 118 SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the 119 BIOS to enable it, it means it has been hidden by the BIOS code. Asus is 120 well known for first doing this on their P4B motherboard, and many other 121 boards after that. Some vendor machines are affected as well. 122 123 The first thing to try is the "i2c_ec" ACPI driver. It could be that the 124 SMBus was hidden on purpose because it'll be driven by ACPI. If the 125 i2c_ec driver works for you, just forget about the i2c-i801 driver and 126 don't try to unhide the ICH SMBus. Even if i2c_ec doesn't work, you 127 better make sure that the SMBus isn't used by the ACPI code. Try loading 128 the "fan" and "thermal" drivers, and check in /proc/acpi/fan and 129 /proc/acpi/thermal_zone. If you find anything there, it's likely that 130 the ACPI is accessing the SMBus and it's safer not to unhide it. Only 131 once you are certain that ACPI isn't using the SMBus, you can attempt 132 to unhide it. 133 134 In order to unhide the SMBus, we need to change the value of a PCI 135 register before the kernel enumerates the PCI devices. This is done in 136 drivers/pci/quirks.c, where all affected boards must be listed (see 137 function asus_hides_smbus_hostbridge.) If the SMBus device is missing, 138 and you think there's something interesting on the SMBus (e.g. a 139 hardware monitoring chip), you need to add your board to the list. 140 141 The motherboard is identified using the subvendor and subdevice IDs of the 142 host bridge PCI device. Get yours with "lspci -n -v -s 00:00.0": 143 144 00:00.0 Class 0600: 8086:2570 (rev 02) 145 Subsystem: 1043:80f2 146 Flags: bus master, fast devsel, latency 0 147 Memory at fc000000 (32-bit, prefetchable) [size=32M] 148 Capabilities: [e4] #09 [2106] 149 Capabilities: [a0] AGP version 3.0 150 151 Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043 152 (Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic 153 names for the bridge ID and the subvendor ID in include/linux/pci_ids.h, 154 and then add a case for your subdevice ID at the right place in 155 drivers/pci/quirks.c. Then please give it very good testing, to make sure 156 that the unhidden SMBus doesn't conflict with e.g. ACPI. 157 158 If it works, proves useful (i.e. there are usable chips on the SMBus) 159 and seems safe, please submit a patch for inclusion into the kernel. 160 161 Note: There's a useful script in lm_sensors 2.10.2 and later, named 162 unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to 163 temporarily unhide the SMBus without having to patch and recompile your 164 kernel. It's very convenient if you just want to check if there's 165 anything interesting on your hidden ICH SMBus. 166 167 168 ********************** 169 The lm_sensors project gratefully acknowledges the support of Texas 170 Instruments in the initial development of this driver. 171 172 The lm_sensors project gratefully acknowledges the support of Intel in the 173 development of SMBus 2.0 / ICH4 features of this driver.