diff options
Diffstat (limited to 'Documentation/i2c/busses/i2c-ali15x3.rst')
| -rw-r--r-- | Documentation/i2c/busses/i2c-ali15x3.rst | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/Documentation/i2c/busses/i2c-ali15x3.rst b/Documentation/i2c/busses/i2c-ali15x3.rst new file mode 100644 index 000000000000..d4c1a2a419cb --- /dev/null +++ b/Documentation/i2c/busses/i2c-ali15x3.rst @@ -0,0 +1,122 @@ +========================= +Kernel driver i2c-ali15x3 +========================= + +Supported adapters: + * Acer Labs, Inc. ALI 1533 and 1543C (south bridge) + + Datasheet: Now under NDA + http://www.ali.com.tw/ + +Authors: + - Frodo Looijaard <frodol@dds.nl>, + - Philip Edelbrock <phil@netroedge.com>, + - Mark D. Studebaker <mdsxyz123@yahoo.com> + +Module Parameters +----------------- + +* force_addr: int + Initialize the base address of the i2c controller + + +Notes +----- + +The force_addr parameter is useful for boards that don't set the address in +the BIOS. Does not do a PCI force; the device must still be present in +lspci. Don't use this unless the driver complains that the base address is +not set. + +Example:: + + modprobe i2c-ali15x3 force_addr=0xe800 + +SMBus periodically hangs on ASUS P5A motherboards and can only be cleared +by a power cycle. Cause unknown (see Issues below). + + +Description +----------- + +This is the driver for the SMB Host controller on Acer Labs Inc. (ALI) +M1541 and M1543C South Bridges. + +The M1543C is a South bridge for desktop systems. + +The M1541 is a South bridge for portable systems. + +They are part of the following ALI chipsets: + + * "Aladdin Pro 2" includes the M1621 Slot 1 North bridge with AGP and + 100MHz CPU Front Side bus + * "Aladdin V" includes the M1541 Socket 7 North bridge with AGP and 100MHz + CPU Front Side bus + + Some Aladdin V motherboards: + - Asus P5A + - Atrend ATC-5220 + - BCM/GVC VP1541 + - Biostar M5ALA + - Gigabyte GA-5AX (Generally doesn't work because the BIOS doesn't + enable the 7101 device!) + - Iwill XA100 Plus + - Micronics C200 + - Microstar (MSI) MS-5169 + + * "Aladdin IV" includes the M1541 Socket 7 North bridge + with host bus up to 83.3 MHz. + +For an overview of these chips see http://www.acerlabs.com. At this time the +full data sheets on the web site are password protected, however if you +contact the ALI office in San Jose they may give you the password. + +The M1533/M1543C devices appear as FOUR separate devices on the PCI bus. An +output of lspci will show something similar to the following:: + + 00:02.0 USB Controller: Acer Laboratories Inc. M5237 (rev 03) + 00:03.0 Bridge: Acer Laboratories Inc. M7101 <= THIS IS THE ONE WE NEED + 00:07.0 ISA bridge: Acer Laboratories Inc. M1533 (rev c3) + 00:0f.0 IDE interface: Acer Laboratories Inc. M5229 (rev c1) + +.. important:: + + If you have a M1533 or M1543C on the board and you get + "ali15x3: Error: Can't detect ali15x3!" + then run lspci. + + If you see the 1533 and 5229 devices but NOT the 7101 device, + then you must enable ACPI, the PMU, SMB, or something similar + in the BIOS. + + The driver won't work if it can't find the M7101 device. + +The SMB controller is part of the M7101 device, which is an ACPI-compliant +Power Management Unit (PMU). + +The whole M7101 device has to be enabled for the SMB to work. You can't +just enable the SMB alone. The SMB and the ACPI have separate I/O spaces. +We make sure that the SMB is enabled. We leave the ACPI alone. + +Features +-------- + +This driver controls the SMB Host only. The SMB Slave +controller on the M15X3 is not enabled. This driver does not use +interrupts. + + +Issues +------ + +This driver requests the I/O space for only the SMB +registers. It doesn't use the ACPI region. + +On the ASUS P5A motherboard, there are several reports that +the SMBus will hang and this can only be resolved by +powering off the computer. It appears to be worse when the board +gets hot, for example under heavy CPU load, or in the summer. +There may be electrical problems on this board. +On the P5A, the W83781D sensor chip is on both the ISA and +SMBus. Therefore the SMBus hangs can generally be avoided +by accessing the W83781D on the ISA bus only. |