Re: [patch 2/5] Staging: vme: add VME userspace driver

From: Martyn Welch
Date: Wed Aug 12 2009 - 05:56:32 EST


Emilio G. Cota wrote:
Martyn Welch wrote:
Also, it seems that your API doesn't currently support Location
Monitors. These are specified in the VME spec, I'd be interested in
how
you plan to support this feature in a consistent manner with your
current API

What I intend to provide is a sane environment to work with VME
devices. The first step is to cover the needs of most use cases:

- 1 master Single Board Computer (SBC) running Linux
- All the other slots have slave devices in them. These devices
are controlled by kernel drivers on the SBC.
- The SBC does DMA, direct I/O access (mapping) to/from the
slaves, and handles interrupts from the devices.

Once that's settled we could discuss about further parts of the
spec. But really today getting the above right is _much_ more
important than location monitors support.
Right - this is a specific case that you see as important. Depending on the number of slots in the rack and the diversity of the cards used, the VME core and driver I have suggested already covers this.

However, I also need to consider other cases, such as communications between multiple SBCs and potentially a few slave devices. I have a need for this *now*, not in the future. To me, slave support and to a lesser degree location monitor support is important now, hence why it's supported in my driver and core. Hence why I am asking, how do you propose to support these features?

Martyn
E.


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