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ccf988b6 | 1 | ====================== |
1da177e4 | 2 | Kernel driver i2c-i801 |
ccf988b6 MCC |
3 | ====================== |
4 | ||
1da177e4 LT |
5 | |
6 | Supported adapters: | |
7 | * Intel 82801AA and 82801AB (ICH and ICH0 - part of the | |
8 | '810' and '810E' chipsets) | |
9 | * Intel 82801BA (ICH2 - part of the '815E' chipset) | |
10 | * Intel 82801CA/CAM (ICH3) | |
7edcb9ab OR |
11 | * Intel 82801DB (ICH4) (HW PEC supported) |
12 | * Intel 82801EB/ER (ICH5) (HW PEC supported) | |
1da177e4 LT |
13 | * Intel 6300ESB |
14 | * Intel 82801FB/FR/FW/FRW (ICH6) | |
a980a99a JG |
15 | * Intel 82801G (ICH7) |
16 | * Intel 631xESB/632xESB (ESB2) | |
17 | * Intel 82801H (ICH8) | |
d28dc711 | 18 | * Intel 82801I (ICH9) |
c429a247 SH |
19 | * Intel EP80579 (Tolapai) |
20 | * Intel 82801JI (ICH10) | |
e30d9859 | 21 | * Intel 5/3400 Series (PCH) |
662cda8a | 22 | * Intel 6 Series (PCH) |
e30d9859 | 23 | * Intel Patsburg (PCH) |
662cda8a | 24 | * Intel DH89xxCC (PCH) |
6e2a851e | 25 | * Intel Panther Point (PCH) |
062737fb | 26 | * Intel Lynx Point (PCH) |
c2db409c | 27 | * Intel Avoton (SOC) |
a3fc0ff0 | 28 | * Intel Wellsburg (PCH) |
f39901c1 | 29 | * Intel Coleto Creek (PCH) |
b299de83 | 30 | * Intel Wildcat Point (PCH) |
1b31e9b7 | 31 | * Intel BayTrail (SOC) |
15407798 | 32 | * Intel Braswell (SOC) |
80d943ab JN |
33 | * Intel Sunrise Point (PCH) |
34 | * Intel Kaby Lake (PCH) | |
2b630df7 JN |
35 | * Intel DNV (SOC) |
36 | * Intel Broxton (SOC) | |
cdc5a311 | 37 | * Intel Lewisburg (PCH) |
9827f9eb | 38 | * Intel Gemini Lake (SOC) |
80d943ab | 39 | * Intel Cannon Lake (PCH) |
cb09d943 | 40 | * Intel Cedar Fork (PCH) |
0bff2a86 | 41 | * Intel Ice Lake (PCH) |
5cd1c56c | 42 | * Intel Comet Lake (PCH) |
9be1485a | 43 | * Intel Elkhart Lake (PCH) |
051d769f | 44 | * Intel Tiger Lake (PCH) |
790591f4 | 45 | * Intel Jasper Lake (SOC) |
12745b07 | 46 | * Intel Emmitsburg (PCH) |
332fdaeb | 47 | * Intel Alder Lake (PCH) |
9c02d401 | 48 | * Intel Raptor Lake (PCH) |
24fff66f | 49 | * Intel Meteor Lake (SOC) |
ccf988b6 | 50 | |
e07bc679 | 51 | Datasheets: Publicly available at the Intel website |
1da177e4 | 52 | |
55fee8d7 DW |
53 | On Intel Patsburg and later chipsets, both the normal host SMBus controller |
54 | and the additional 'Integrated Device Function' controllers are supported. | |
55 | ||
ccf988b6 MCC |
56 | Authors: |
57 | - Mark Studebaker <mdsxyz123@yahoo.com> | |
58 | - Jean Delvare <jdelvare@suse.de> | |
1da177e4 LT |
59 | |
60 | ||
61 | Module Parameters | |
62 | ----------------- | |
63 | ||
adff687d | 64 | * disable_features (bit vector) |
ccf988b6 | 65 | |
adff687d JD |
66 | Disable selected features normally supported by the device. This makes it |
67 | possible to work around possible driver or hardware bugs if the feature in | |
68 | question doesn't work as intended for whatever reason. Bit values: | |
ccf988b6 MCC |
69 | |
70 | ==== ========================================= | |
636752bc DK |
71 | 0x01 disable SMBus PEC |
72 | 0x02 disable the block buffer | |
73 | 0x08 disable the I2C block read functionality | |
74 | 0x10 don't use interrupts | |
ed6182a8 | 75 | 0x20 disable SMBus Host Notify |
ccf988b6 | 76 | ==== ========================================= |
1da177e4 LT |
77 | |
78 | ||
79 | Description | |
80 | ----------- | |
81 | ||
82 | The ICH (properly known as the 82801AA), ICH0 (82801AB), ICH2 (82801BA), | |
c429a247 | 83 | ICH3 (82801CA/CAM) and later devices (PCH) are Intel chips that are a part of |
1da177e4 LT |
84 | Intel's '810' chipset for Celeron-based PCs, '810E' chipset for |
85 | Pentium-based PCs, '815E' chipset, and others. | |
86 | ||
87 | The ICH chips contain at least SEVEN separate PCI functions in TWO logical | |
88 | PCI devices. An output of lspci will show something similar to the | |
ccf988b6 | 89 | following:: |
1da177e4 LT |
90 | |
91 | 00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01) | |
92 | 00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01) | |
93 | 00:1f.1 IDE interface: Intel Corporation: Unknown device 2411 (rev 01) | |
94 | 00:1f.2 USB Controller: Intel Corporation: Unknown device 2412 (rev 01) | |
95 | 00:1f.3 Unknown class [0c05]: Intel Corporation: Unknown device 2413 (rev 01) | |
96 | ||
97 | The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial | |
98 | Controller. | |
99 | ||
1da177e4 LT |
100 | The ICH chips are quite similar to Intel's PIIX4 chip, at least in the |
101 | SMBus controller. | |
102 | ||
1da177e4 LT |
103 | |
104 | Process Call Support | |
105 | -------------------- | |
106 | ||
315cd67c | 107 | Block process call is supported on the 82801EB (ICH5) and later chips. |
1da177e4 LT |
108 | |
109 | ||
110 | I2C Block Read Support | |
111 | ---------------------- | |
112 | ||
6342064c | 113 | I2C block read is supported on the 82801EB (ICH5) and later chips. |
1da177e4 LT |
114 | |
115 | ||
116 | SMBus 2.0 Support | |
117 | ----------------- | |
118 | ||
119 | The 82801DB (ICH4) and later chips support several SMBus 2.0 features. | |
120 | ||
099ab118 | 121 | |
636752bc DK |
122 | Interrupt Support |
123 | ----------------- | |
124 | ||
125 | PCI interrupt support is supported on the 82801EB (ICH5) and later chips. | |
126 | ||
127 | ||
099ab118 JD |
128 | Hidden ICH SMBus |
129 | ---------------- | |
130 | ||
131 | If your system has an Intel ICH south bridge, but you do NOT see the | |
132 | SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the | |
133 | BIOS to enable it, it means it has been hidden by the BIOS code. Asus is | |
134 | well known for first doing this on their P4B motherboard, and many other | |
135 | boards after that. Some vendor machines are affected as well. | |
136 | ||
ed6182a8 | 137 | The first thing to try is the "i2c-scmi" ACPI driver. It could be that the |
099ab118 | 138 | SMBus was hidden on purpose because it'll be driven by ACPI. If the |
ed6182a8 JD |
139 | i2c-scmi driver works for you, just forget about the i2c-i801 driver and |
140 | don't try to unhide the ICH SMBus. Even if i2c-scmi doesn't work, you | |
099ab118 | 141 | better make sure that the SMBus isn't used by the ACPI code. Try loading |
ed6182a8 JD |
142 | the "fan" and "thermal" drivers, and check in /sys/class/thermal. If you |
143 | find a thermal zone with type "acpitz", it's likely that the ACPI is | |
144 | accessing the SMBus and it's safer not to unhide it. Only once you are | |
145 | certain that ACPI isn't using the SMBus, you can attempt to unhide it. | |
099ab118 JD |
146 | |
147 | In order to unhide the SMBus, we need to change the value of a PCI | |
148 | register before the kernel enumerates the PCI devices. This is done in | |
149 | drivers/pci/quirks.c, where all affected boards must be listed (see | |
150 | function asus_hides_smbus_hostbridge.) If the SMBus device is missing, | |
151 | and you think there's something interesting on the SMBus (e.g. a | |
152 | hardware monitoring chip), you need to add your board to the list. | |
153 | ||
154 | The motherboard is identified using the subvendor and subdevice IDs of the | |
ccf988b6 | 155 | host bridge PCI device. Get yours with ``lspci -n -v -s 00:00.0``:: |
099ab118 | 156 | |
ccf988b6 MCC |
157 | 00:00.0 Class 0600: 8086:2570 (rev 02) |
158 | Subsystem: 1043:80f2 | |
159 | Flags: bus master, fast devsel, latency 0 | |
160 | Memory at fc000000 (32-bit, prefetchable) [size=32M] | |
161 | Capabilities: [e4] #09 [2106] | |
162 | Capabilities: [a0] AGP version 3.0 | |
099ab118 JD |
163 | |
164 | Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043 | |
165 | (Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic | |
166 | names for the bridge ID and the subvendor ID in include/linux/pci_ids.h, | |
167 | and then add a case for your subdevice ID at the right place in | |
168 | drivers/pci/quirks.c. Then please give it very good testing, to make sure | |
169 | that the unhidden SMBus doesn't conflict with e.g. ACPI. | |
170 | ||
171 | If it works, proves useful (i.e. there are usable chips on the SMBus) | |
172 | and seems safe, please submit a patch for inclusion into the kernel. | |
173 | ||
174 | Note: There's a useful script in lm_sensors 2.10.2 and later, named | |
175 | unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to | |
176 | temporarily unhide the SMBus without having to patch and recompile your | |
177 | kernel. It's very convenient if you just want to check if there's | |
178 | anything interesting on your hidden ICH SMBus. | |
179 | ||
180 | ||
ccf988b6 MCC |
181 | ---------------------------------------------------------------------------- |
182 | ||
1da177e4 LT |
183 | The lm_sensors project gratefully acknowledges the support of Texas |
184 | Instruments in the initial development of this driver. | |
185 | ||
186 | The lm_sensors project gratefully acknowledges the support of Intel in the | |
187 | development of SMBus 2.0 / ICH4 features of this driver. |