Re: Naming of peripheral bus on SoC's

[Simon Burge <simonb%NetBSD.org@localhost>]

Masao Uebayashi wrote:

> All those SoC's name their peripheral buses for their own, like aubus
> of Alchemy and siobio of SiByte, etc.  I don't think there's much
> point of doing this.  I think having a common name helps read code.
> 
> My idea is, ocio(4) (on-chip I/O) for on-chip peripherals, and obio(4)
> (on-board I/O) , which is already widely used, for on-board devices
> mapped in physical memory space.

Some SoC's have multiple busses that are all on-chip.  The SiByte SoC's
are one example of this, as are the PowerPC 405 SoC's.

The line between "ocio" and "obio" can be blurred a bit too.  The SiByte
boards for example use "obio" for some on-chip devices and another
"scscd" for others, while the on-board devices (flash, LEDs) don't have
drivers (we ignore flash, and LEDs are controlled by talking directly to
external memory mapped address and not through a normal device driver).
So there's "on chip internal" devices, "on chip external" devices and
"on board external" devices.

I'm not really strongly against renaming all the busses, but I'm not
sure I can see a simple generic solution with ocio and obio that can
cover all situations.

Cheers,
Simon.