1 ====================== 1 ======================
2 Kernel driver i2c-i801 2 Kernel driver i2c-i801
3 ====================== 3 ======================
4 4
5 5
6 Supported adapters: 6 Supported adapters:
7 * Intel 82801AA and 82801AB (ICH and ICH0 - 7 * Intel 82801AA and 82801AB (ICH and ICH0 - part of the
8 '810' and '810E' chipsets) 8 '810' and '810E' chipsets)
9 * Intel 82801BA (ICH2 - part of the '815E' c 9 * Intel 82801BA (ICH2 - part of the '815E' chipset)
10 * Intel 82801CA/CAM (ICH3) 10 * Intel 82801CA/CAM (ICH3)
11 * Intel 82801DB (ICH4) (HW PEC supported) 11 * Intel 82801DB (ICH4) (HW PEC supported)
12 * Intel 82801EB/ER (ICH5) (HW PEC supported) 12 * Intel 82801EB/ER (ICH5) (HW PEC supported)
13 * Intel 6300ESB 13 * Intel 6300ESB
14 * Intel 82801FB/FR/FW/FRW (ICH6) 14 * Intel 82801FB/FR/FW/FRW (ICH6)
15 * Intel 82801G (ICH7) 15 * Intel 82801G (ICH7)
16 * Intel 631xESB/632xESB (ESB2) 16 * Intel 631xESB/632xESB (ESB2)
17 * Intel 82801H (ICH8) 17 * Intel 82801H (ICH8)
18 * Intel 82801I (ICH9) 18 * Intel 82801I (ICH9)
19 * Intel EP80579 (Tolapai) 19 * Intel EP80579 (Tolapai)
20 * Intel 82801JI (ICH10) 20 * Intel 82801JI (ICH10)
21 * Intel 5/3400 Series (PCH) 21 * Intel 5/3400 Series (PCH)
22 * Intel 6 Series (PCH) 22 * Intel 6 Series (PCH)
23 * Intel Patsburg (PCH) 23 * Intel Patsburg (PCH)
24 * Intel DH89xxCC (PCH) 24 * Intel DH89xxCC (PCH)
25 * Intel Panther Point (PCH) 25 * Intel Panther Point (PCH)
26 * Intel Lynx Point (PCH) 26 * Intel Lynx Point (PCH)
27 * Intel Avoton (SOC) 27 * Intel Avoton (SOC)
28 * Intel Wellsburg (PCH) 28 * Intel Wellsburg (PCH)
29 * Intel Coleto Creek (PCH) 29 * Intel Coleto Creek (PCH)
30 * Intel Wildcat Point (PCH) 30 * Intel Wildcat Point (PCH)
31 * Intel BayTrail (SOC) 31 * Intel BayTrail (SOC)
32 * Intel Braswell (SOC) 32 * Intel Braswell (SOC)
33 * Intel Sunrise Point (PCH) 33 * Intel Sunrise Point (PCH)
34 * Intel Kaby Lake (PCH) 34 * Intel Kaby Lake (PCH)
35 * Intel DNV (SOC) 35 * Intel DNV (SOC)
36 * Intel Broxton (SOC) 36 * Intel Broxton (SOC)
37 * Intel Lewisburg (PCH) 37 * Intel Lewisburg (PCH)
38 * Intel Gemini Lake (SOC) 38 * Intel Gemini Lake (SOC)
39 * Intel Cannon Lake (PCH) 39 * Intel Cannon Lake (PCH)
40 * Intel Cedar Fork (PCH) 40 * Intel Cedar Fork (PCH)
41 * Intel Ice Lake (PCH) 41 * Intel Ice Lake (PCH)
42 * Intel Comet Lake (PCH) 42 * Intel Comet Lake (PCH)
43 * Intel Elkhart Lake (PCH) 43 * Intel Elkhart Lake (PCH)
44 * Intel Tiger Lake (PCH) 44 * Intel Tiger Lake (PCH)
45 * Intel Jasper Lake (SOC) 45 * Intel Jasper Lake (SOC)
46 * Intel Emmitsburg (PCH) 46 * Intel Emmitsburg (PCH)
47 * Intel Alder Lake (PCH) 47 * Intel Alder Lake (PCH)
48 * Intel Raptor Lake (PCH) 48 * Intel Raptor Lake (PCH)
49 * Intel Meteor Lake (SOC and PCH) 49 * Intel Meteor Lake (SOC and PCH)
50 * Intel Birch Stream (SOC) 50 * Intel Birch Stream (SOC)
51 * Intel Arrow Lake (SOC) 51 * Intel Arrow Lake (SOC)
52 52
53 Datasheets: Publicly available at the Intel 53 Datasheets: Publicly available at the Intel website
54 54
55 On Intel Patsburg and later chipsets, both the 55 On Intel Patsburg and later chipsets, both the normal host SMBus controller
56 and the additional 'Integrated Device Function 56 and the additional 'Integrated Device Function' controllers are supported.
57 57
58 Authors: 58 Authors:
59 - Mark Studebaker <mdsxyz123@yahoo.com> 59 - Mark Studebaker <mdsxyz123@yahoo.com>
60 - Jean Delvare <jdelvare@suse.de> 60 - Jean Delvare <jdelvare@suse.de>
61 61
62 62
63 Module Parameters 63 Module Parameters
64 ----------------- 64 -----------------
65 65
66 * disable_features (bit vector) 66 * disable_features (bit vector)
67 67
68 Disable selected features normally supported b 68 Disable selected features normally supported by the device. This makes it
69 possible to work around possible driver or har 69 possible to work around possible driver or hardware bugs if the feature in
70 question doesn't work as intended for whatever 70 question doesn't work as intended for whatever reason. Bit values:
71 71
72 ==== ======================================= 72 ==== =========================================
73 0x01 disable SMBus PEC 73 0x01 disable SMBus PEC
74 0x02 disable the block buffer 74 0x02 disable the block buffer
75 0x08 disable the I2C block read functionalit 75 0x08 disable the I2C block read functionality
76 0x10 don't use interrupts 76 0x10 don't use interrupts
77 0x20 disable SMBus Host Notify 77 0x20 disable SMBus Host Notify
78 ==== ======================================= 78 ==== =========================================
79 79
80 80
81 Description 81 Description
82 ----------- 82 -----------
83 83
84 The ICH (properly known as the 82801AA), ICH0 84 The ICH (properly known as the 82801AA), ICH0 (82801AB), ICH2 (82801BA),
85 ICH3 (82801CA/CAM) and later devices (PCH) are 85 ICH3 (82801CA/CAM) and later devices (PCH) are Intel chips that are a part of
86 Intel's '810' chipset for Celeron-based PCs, ' 86 Intel's '810' chipset for Celeron-based PCs, '810E' chipset for
87 Pentium-based PCs, '815E' chipset, and others. 87 Pentium-based PCs, '815E' chipset, and others.
88 88
89 The ICH chips contain at least SEVEN separate 89 The ICH chips contain at least SEVEN separate PCI functions in TWO logical
90 PCI devices. An output of lspci will show some 90 PCI devices. An output of lspci will show something similar to the
91 following:: 91 following::
92 92
93 00:1e.0 PCI bridge: Intel Corporation: Unkno 93 00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01)
94 00:1f.0 ISA bridge: Intel Corporation: Unkno 94 00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01)
95 00:1f.1 IDE interface: Intel Corporation: Un 95 00:1f.1 IDE interface: Intel Corporation: Unknown device 2411 (rev 01)
96 00:1f.2 USB Controller: Intel Corporation: U 96 00:1f.2 USB Controller: Intel Corporation: Unknown device 2412 (rev 01)
97 00:1f.3 Unknown class [0c05]: Intel Corporat 97 00:1f.3 Unknown class [0c05]: Intel Corporation: Unknown device 2413 (rev 01)
98 98
99 The SMBus controller is function 3 in device 1 99 The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial
100 Controller. 100 Controller.
101 101
102 The ICH chips are quite similar to Intel's PII 102 The ICH chips are quite similar to Intel's PIIX4 chip, at least in the
103 SMBus controller. 103 SMBus controller.
104 104
105 105
106 Process Call Support 106 Process Call Support
107 -------------------- 107 --------------------
108 108
109 Block process call is supported on the 82801EB 109 Block process call is supported on the 82801EB (ICH5) and later chips.
110 110
111 111
112 I2C Block Read Support 112 I2C Block Read Support
113 ---------------------- 113 ----------------------
114 114
115 I2C block read is supported on the 82801EB (IC 115 I2C block read is supported on the 82801EB (ICH5) and later chips.
116 116
117 117
118 SMBus 2.0 Support 118 SMBus 2.0 Support
119 ----------------- 119 -----------------
120 120
121 The 82801DB (ICH4) and later chips support sev 121 The 82801DB (ICH4) and later chips support several SMBus 2.0 features.
122 122
123 123
124 Interrupt Support 124 Interrupt Support
125 ----------------- 125 -----------------
126 126
127 PCI interrupt support is supported on the 8280 127 PCI interrupt support is supported on the 82801EB (ICH5) and later chips.
128 128
129 129
130 Hidden ICH SMBus 130 Hidden ICH SMBus
131 ---------------- 131 ----------------
132 132
133 If your system has an Intel ICH south bridge, 133 If your system has an Intel ICH south bridge, but you do NOT see the
134 SMBus device at 00:1f.3 in lspci, and you can' 134 SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the
135 BIOS to enable it, it means it has been hidden 135 BIOS to enable it, it means it has been hidden by the BIOS code. Asus is
136 well known for first doing this on their P4B m 136 well known for first doing this on their P4B motherboard, and many other
137 boards after that. Some vendor machines are af 137 boards after that. Some vendor machines are affected as well.
138 138
139 The first thing to try is the "i2c-scmi" ACPI 139 The first thing to try is the "i2c-scmi" ACPI driver. It could be that the
140 SMBus was hidden on purpose because it'll be d 140 SMBus was hidden on purpose because it'll be driven by ACPI. If the
141 i2c-scmi driver works for you, just forget abo 141 i2c-scmi driver works for you, just forget about the i2c-i801 driver and
142 don't try to unhide the ICH SMBus. Even if i2c 142 don't try to unhide the ICH SMBus. Even if i2c-scmi doesn't work, you
143 better make sure that the SMBus isn't used by 143 better make sure that the SMBus isn't used by the ACPI code. Try loading
144 the "fan" and "thermal" drivers, and check in 144 the "fan" and "thermal" drivers, and check in /sys/class/thermal. If you
145 find a thermal zone with type "acpitz", it's l 145 find a thermal zone with type "acpitz", it's likely that the ACPI is
146 accessing the SMBus and it's safer not to unhi 146 accessing the SMBus and it's safer not to unhide it. Only once you are
147 certain that ACPI isn't using the SMBus, you c 147 certain that ACPI isn't using the SMBus, you can attempt to unhide it.
148 148
149 In order to unhide the SMBus, we need to chang 149 In order to unhide the SMBus, we need to change the value of a PCI
150 register before the kernel enumerates the PCI 150 register before the kernel enumerates the PCI devices. This is done in
151 drivers/pci/quirks.c, where all affected board 151 drivers/pci/quirks.c, where all affected boards must be listed (see
152 function asus_hides_smbus_hostbridge.) If the 152 function asus_hides_smbus_hostbridge.) If the SMBus device is missing,
153 and you think there's something interesting on 153 and you think there's something interesting on the SMBus (e.g. a
154 hardware monitoring chip), you need to add you 154 hardware monitoring chip), you need to add your board to the list.
155 155
156 The motherboard is identified using the subven 156 The motherboard is identified using the subvendor and subdevice IDs of the
157 host bridge PCI device. Get yours with ``lspci 157 host bridge PCI device. Get yours with ``lspci -n -v -s 00:00.0``::
158 158
159 00:00.0 Class 0600: 8086:2570 (rev 02) 159 00:00.0 Class 0600: 8086:2570 (rev 02)
160 Subsystem: 1043:80f2 160 Subsystem: 1043:80f2
161 Flags: bus master, fast devsel, late 161 Flags: bus master, fast devsel, latency 0
162 Memory at fc000000 (32-bit, prefetch 162 Memory at fc000000 (32-bit, prefetchable) [size=32M]
163 Capabilities: [e4] #09 [2106] 163 Capabilities: [e4] #09 [2106]
164 Capabilities: [a0] AGP version 3.0 164 Capabilities: [a0] AGP version 3.0
165 165
166 Here the host bridge ID is 2570 (82865G/PE/P), 166 Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043
167 (Asus) and the subdevice ID is 80f2 (P4P800-X) 167 (Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic
168 names for the bridge ID and the subvendor ID i 168 names for the bridge ID and the subvendor ID in include/linux/pci_ids.h,
169 and then add a case for your subdevice ID at t 169 and then add a case for your subdevice ID at the right place in
170 drivers/pci/quirks.c. Then please give it very 170 drivers/pci/quirks.c. Then please give it very good testing, to make sure
171 that the unhidden SMBus doesn't conflict with 171 that the unhidden SMBus doesn't conflict with e.g. ACPI.
172 172
173 If it works, proves useful (i.e. there are usa 173 If it works, proves useful (i.e. there are usable chips on the SMBus)
174 and seems safe, please submit a patch for incl 174 and seems safe, please submit a patch for inclusion into the kernel.
175 175
176 Note: There's a useful script in lm_sensors 2. 176 Note: There's a useful script in lm_sensors 2.10.2 and later, named
177 unhide_ICH_SMBus (in prog/hotplug), which uses 177 unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to
178 temporarily unhide the SMBus without having to 178 temporarily unhide the SMBus without having to patch and recompile your
179 kernel. It's very convenient if you just want 179 kernel. It's very convenient if you just want to check if there's
180 anything interesting on your hidden ICH SMBus. 180 anything interesting on your hidden ICH SMBus.
181 181
182 182
183 ---------------------------------------------- 183 ----------------------------------------------------------------------------
184 184
185 The lm_sensors project gratefully acknowledges 185 The lm_sensors project gratefully acknowledges the support of Texas
186 Instruments in the initial development of this 186 Instruments in the initial development of this driver.
187 187
188 The lm_sensors project gratefully acknowledges 188 The lm_sensors project gratefully acknowledges the support of Intel in the
189 development of SMBus 2.0 / ICH4 features of th 189 development of SMBus 2.0 / ICH4 features of this driver.
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