SuperIO SSTD generator¶
This page describes the common SSDT ACPI generator for SuperIO chips that can be found in coreboot.
In order to automatically generate ACPI functions you need to add
chip superio/common and
device pnp xx.0 on to your devicetree.
The xx denotes the hexadecimal address of the SuperIO.
Place the regular LDN pnp devices behind those two entries.
The code will automatically guess the function based on the decoded I/O range and ISA IRQ number.
This example is based on AST2400.
# Add a "container" for proper ACPI code generation
device pnp 2e.0 on # just for the base device, not for the LDNs
device pnp 2e.0 off end
device pnp 2e.2 on # SUART1
io 0x60 = 0x3f8
irq 0x70 = 4
device pnp 2e.3 on # SUART2
io 0x60 = 0x2f8
irq 0x70 = 3
device pnp 2e.4 on # SWC
io 0x60 = 0xa00
io 0x62 = 0xa10
io 0x64 = 0xa20
io 0x66 = 0xa30
irq 0x70 = 0
Automatically generated methods¶
The following methods are generated for each SuperIO:
Acquire the global mutex and enter config mode. It’s called this at the beginning of an atomic operation to make sure no other ACPI code messes with the config space while working on it.
Exit config mode and release the global mutex. It’s called at the end of an atomic operation.
Selects the (virtual) LDN given as Arg0. This method isn’t guarded with the global mutex.
Disables the (virtual) LDN given as Arg0. This method acquires the global mutex.
Queries the state of the (virtual) LDN given as Arg0. This method quires the global mutex.
- Add ACPI HIDs to every SuperIO driver
- Generate support methods that allow
- Setting resource settings at runtime
- Getting resource settings at runtime