elansc - AMD Elan SC520 System Controller driver
elansc* at pci? dev ? function ?
gpio* at elansc?
The 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 timers.
The Elan SC520 also provides several special on-chip devices. The following
are supported by the elansc driver:
+o Watchdog timer. The watchdog timer may be configured
for a 1 second,
2 second, 4 second, 8 second, 16 second, or 32 second
expiration period.
+o 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 gpio(4)
framework. The
gpioctl(8) program allows easy manipulation of pins from
userland.
geodesc(4), gpio(4), intro(4), gpioctl(8), sysctl(8)
Support for the elansc was added in OpenBSD 3.3. PIO function support
appeared in OpenBSD 3.6.
The elansc driver was written by Jason R. Thorpe <thor[email protected]>.
Jasper Wallace provided the work-around for a hardware bug
related to the
watchdog timer in some steppings of the SC520 CPU.
Alexander Yurchenko <[email protected]> added support for
the PIO function.
OpenBSD 3.6 August 11, 2002
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