AMD Elan SC520 System Controller with watchdog timer
elansc* at pci?
gpio* at elansc?
driver supports the system
controller of the AMD Elan SC520 microcontroller. The SC520 consists of an AMD
Am5x86 processor core, integrated PCI host controller, and several standard
on-chip devices, such as NS16550-compatible UARTs, real-time clock, and
The Elan SC520 also provides several special on-chip devices. The following are
supported by the
- Watchdog timer. The watchdog timer may be configured for a 1 second, 2
second, 4 second, 8 second, 16 second, or 32 second expiration
- Programmable Input/Output. The SC520 microcontroller supports 32
programmable I/O signals (PIOs) that can be used on the system board to
monitor signals or control devices that are not handled by the other
functions in the SC520 microcontroller. These signals can be programmed to
be inputs or to be driven out “high” or “low”
as outputs. Pins can be accessed through the
program allows easy manipulation of pins from userland.
Support for the
was added in
. PIO function support appeared in
driver was written by
Jason R. Thorpe
provided the work-around for
a hardware bug related to the watchdog timer in some steppings of the SC520
CPU. Alexander Yurchenko
added support for the PIO function.