This document specifies the application of Open Firmware to the PowerPC Common Hardware Reference Platform (CHRP) ISA base audio controller, including device-specific requirements and practices for initialization, properties, and methods. This device shall be a child of an ISA or EISA Bus Node.

2. Revision History

Revision 1.0 Unapproved DRAFT , Initial revision. Jordan Brown, Sunsoft and John Kingman, IBM editors

3. References

This Open Firmware System binding standard shall be used in conjunction with the following publications. When the following standards are superseded by an approved revision, the revision shall apply.

[1]: IEEE Std 1275-1994 Standard for Boot (Initialization, Configuration) Firmware, Core Practices and Requirements.
[2]: Core Errata, IEEE P1275.7/D4.
[3]: ISA/EISA/ISA-PnP binding to: IEEE Std 1275-1994, Standard for Boot (Initialization, Configuration) Firmware.
[4]: Device Support Extensions to: IEEE Std 1275-1994, Standard for Boot (Initialization, Configuration) Firmware.
[5]: PowerPC Microprocessor Common Hardware Reference Platform: I/O Device Reference. This document describes the PowerPC Common Hardware Reference Platform (CHRP) System Standard I/O Devices; hardware registers, register locations, and hardware attributes.
[6]: Open Firmware Recommended Practice: Generic Names.
[7]: Open Firmware Recommended Practice: Interrupt Mapping.
[8]: PowerPC Microprocessor Common Hardware Reference Platform binding to: IEEE Std 1275-1994, Standard for Boot (Initialization, Configuration) Firmware.

4. Definition of Terms

EISA: Extended Industry Standard Architecture

ISA: Industry Standard Architecture

5. Device Characteristics (Informative)

The CHRP audio device supplies basic, mature function for the recording, playback, and mixing of sound, as specified in [5].

6. Device-specific Configuration Variables

None.

7. Device Nodes

7.1. Properties

As specified in [1], [3] and [8], with the following additions or modifications.

7.1.1. Open Firmware-defined Properties for Device Nodes

"name" S

Standard property name, specifies the generic name of the device.

The meaning of this property is as defined in Open Firmware core document [1], as modified by the Generic Names Recommended Practice[6]. The value for nodes described by this specification shall be "sound."

"device_type" S

Standard property name to define the device's implemented interface.

The meaning of this property is as defined in the Open Firmware core document [1]. The value for nodes described by this specification shall be "sound."

"compatible" S

Standard property name, specifies device names with which this device is compatible.

The meaning of this property is as defined in Open Firmware, as modified by the Generic Names Recommended Practice[6]. As described in those documents, the entries are a list of device names with which this device is compatible, starting with the name of the device itself and progressing through successively less precise and possibly less functional compatible devices.

The value of this property shall include "pnpPNP,b007."

Additional entries may be supplied, at their appropriate position in the list, to describe devices with which this device is compatible.

"reg" S

Standard property name to define the package's registers.

The meaning of this property is as defined in the Open Firmware core document [1]. It describes the device's register set. The values which shall be assigned to this property are explained in the ISA/EISA/ISA-PnP binding[3]. The values provided shall provide compatibility with the Microsoft Windows Sound System.

"interrupts" S

Standard property name to define the package's interrupts.

The meaning of this property is as defined in the Interrupt Mapping Recommended Practice [7]. The values assigned to this property are explained in the ISA/EISA/ISA-PnP binding[3]. The value of this property shall reflect the interrupts used by the device.

"dma" S

Standard property name to define a package's DMA channels.

The values assigned to this property are explained in the ISA/EISA/ISA-PnP binding[3]. The value of this property shall be the numbers of the DMA channels assigned to this device. This device shall have two DMA channels assigned to it. The first component of the array shall be the DMA channel for recording; the second component shall be the DMA channel assigned for playback.

CHRP(TM) ISA Audio Device Binding to IEEE 1275-1994 Standard for Boot (Initialization, Configuration) Firmware