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Documentation / i2c / busses / i2c-ali15x3


Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.

1	Kernel driver i2c-ali15x3
2	
3	Supported adapters:
4	  * Acer Labs, Inc. ALI 1533 and 1543C (south bridge)
5	    Datasheet: Now under NDA
6		http://www.ali.com.tw/
7	
8	Authors:
9		Frodo Looijaard <frodol@dds.nl>,
10		Philip Edelbrock <phil@netroedge.com>,
11		Mark D. Studebaker <mdsxyz123@yahoo.com>
12	
13	Module Parameters
14	-----------------
15	
16	* force_addr: int
17	  Initialize the base address of the i2c controller
18	
19	
20	Notes
21	-----
22	
23	The force_addr parameter is useful for boards that don't set the address in
24	the BIOS. Does not do a PCI force; the device must still be present in
25	lspci. Don't use this unless the driver complains that the base address is
26	not set.
27	
28	Example: 'modprobe i2c-ali15x3 force_addr=0xe800'
29	
30	SMBus periodically hangs on ASUS P5A motherboards and can only be cleared
31	by a power cycle. Cause unknown (see Issues below).
32	
33	
34	Description
35	-----------
36	
37	This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
38	M1541 and M1543C South Bridges.
39	
40	The M1543C is a South bridge for desktop systems.
41	The M1541 is a South bridge for portable systems.
42	They 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	
62	For an overview of these chips see http://www.acerlabs.com. At this time the
63	full data sheets on the web site are password protected, however if you
64	contact the ALI office in San Jose they may give you the password.
65	
66	The M1533/M1543C devices appear as FOUR separate devices on the PCI bus. An
67	output 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	
83	The SMB controller is part of the M7101 device, which is an ACPI-compliant
84	Power Management Unit (PMU).
85	
86	The whole M7101 device has to be enabled for the SMB to work. You can't
87	just enable the SMB alone. The SMB and the ACPI have separate I/O spaces.
88	We make sure that the SMB is enabled. We leave the ACPI alone.
89	
90	Features
91	--------
92	
93	This driver controls the SMB Host only. The SMB Slave
94	controller on the M15X3 is not enabled. This driver does not use
95	interrupts.
96	
97	
98	Issues
99	------
100	
101	This driver requests the I/O space for only the SMB
102	registers. It doesn't use the ACPI region.
103	
104	On the ASUS P5A motherboard, there are several reports that
105	the SMBus will hang and this can only be resolved by
106	powering off the computer. It appears to be worse when the board
107	gets hot, for example under heavy CPU load, or in the summer.
108	There may be electrical problems on this board.
109	On the P5A, the W83781D sensor chip is on both the ISA and
110	SMBus. Therefore the SMBus hangs can generally be avoided
111	by accessing the W83781D on the ISA bus only.
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