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/ 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. 112 113