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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/i2c/busses/i2c-ali15x3
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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1Kernel driver i2c-ali15x3
2
3Supported adapters:
4 * Acer Labs, Inc. ALI 1533 and 1543C (south bridge)
5 Datasheet: Now under NDA
6 http://www.ali.com.tw/eng/support/datasheet_request.php
7
8Authors:
9 Frodo Looijaard <frodol@dds.nl>,
10 Philip Edelbrock <phil@netroedge.com>,
11 Mark D. Studebaker <mdsxyz123@yahoo.com>
12
13Module Parameters
14-----------------
15
16* force_addr: int
17 Initialize the base address of the i2c controller
18
19
20Notes
21-----
22
23The force_addr parameter is useful for boards that don't set the address in
24the BIOS. Does not do a PCI force; the device must still be present in
25lspci. Don't use this unless the driver complains that the base address is
26not set.
27
28Example: 'modprobe i2c-ali15x3 force_addr=0xe800'
29
30SMBus periodically hangs on ASUS P5A motherboards and can only be cleared
31by a power cycle. Cause unknown (see Issues below).
32
33
34Description
35-----------
36
37This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
38M1541 and M1543C South Bridges.
39
40The M1543C is a South bridge for desktop systems.
41The M1541 is a South bridge for portable systems.
42They are part of the following ALI chipsets:
43
44 * "Aladdin Pro 2" includes the M1621 Slot 1 North bridge with AGP and
45 100MHz CPU Front Side bus
46 * "Aladdin V" includes the M1541 Socket 7 North bridge with AGP and 100MHz
47 CPU Front Side bus
48 Some Aladdin V motherboards:
49 Asus P5A
50 Atrend ATC-5220
51 BCM/GVC VP1541
52 Biostar M5ALA
53 Gigabyte GA-5AX (** Generally doesn't work because the BIOS doesn't
54 enable the 7101 device! **)
55 Iwill XA100 Plus
56 Micronics C200
57 Microstar (MSI) MS-5169
58
59 * "Aladdin IV" includes the M1541 Socket 7 North bridge
60 with host bus up to 83.3 MHz.
61
62For an overview of these chips see http://www.acerlabs.com. At this time the
63full data sheets on the web site are password protected, however if you
64contact the ALI office in San Jose they may give you the password.
65
66The M1533/M1543C devices appear as FOUR separate devices on the PCI bus. An
67output of lspci will show something similar to the following:
68
69 00:02.0 USB Controller: Acer Laboratories Inc. M5237 (rev 03)
70 00:03.0 Bridge: Acer Laboratories Inc. M7101 <= THIS IS THE ONE WE NEED
71 00:07.0 ISA bridge: Acer Laboratories Inc. M1533 (rev c3)
72 00:0f.0 IDE interface: Acer Laboratories Inc. M5229 (rev c1)
73
74** IMPORTANT **
75** If you have a M1533 or M1543C on the board and you get
76** "ali15x3: Error: Can't detect ali15x3!"
77** then run lspci.
78** If you see the 1533 and 5229 devices but NOT the 7101 device,
79** then you must enable ACPI, the PMU, SMB, or something similar
80** in the BIOS.
81** The driver won't work if it can't find the M7101 device.
82
83The SMB controller is part of the M7101 device, which is an ACPI-compliant
84Power Management Unit (PMU).
85
86The whole M7101 device has to be enabled for the SMB to work. You can't
87just enable the SMB alone. The SMB and the ACPI have separate I/O spaces.
88We make sure that the SMB is enabled. We leave the ACPI alone.
89
90Features
91--------
92
93This driver controls the SMB Host only. The SMB Slave
94controller on the M15X3 is not enabled. This driver does not use
95interrupts.
96
97
98Issues
99------
100
101This driver requests the I/O space for only the SMB
102registers. It doesn't use the ACPI region.
103
104On the ASUS P5A motherboard, there are several reports that
105the SMBus will hang and this can only be resolved by
106powering off the computer. It appears to be worse when the board
107gets hot, for example under heavy CPU load, or in the summer.
108There may be electrical problems on this board.
109On the P5A, the W83781D sensor chip is on both the ISA and
110SMBus. Therefore the SMBus hangs can generally be avoided
111by accessing the W83781D on the ISA bus only.
112