Re: Is there a binding for IORESOURCE_DMA population?
From: Shawn Guo <hidden>
Date: 2011-07-17 07:30:52
On Sat, Jul 16, 2011 at 02:16:40PM -0500, Rob Herring wrote:
On 07/16/2011 09:40 AM, Shawn Guo wrote:quoted
On Sat, Jul 16, 2011 at 08:55:41PM +0800, Tabi Timur-B04825 wrote:quoted
Arnd Bergmann wrote:quoted
Right, this is what I had in mind. I think this is reasonable. If you need so many channels, the device tree will be huge already, so this doesn't add that much bloat either.I'm not sure I agree. It seems that specifying nodes for each DMA channel (virtual or physical) is meaningless because the only property in the node is the "reg", which is really just a cell-index in disguise.Yes, that's exactly why I do not appreciate the solution.quoted
My vote is to have a node only for the DMA engine, and let the DMA handle the virtual and physical channels internally.It's not about virtual or physical channel. I'm asking suggestion on how we bind the channel number for each dma client device in device tree and how they will get the number from device tree when they get probed.In this case, it is the event (or request line) that is important not the channel assignment.
Exactly.
This is how the hardware is wired up and the main variation between chips with SDMA. Since DT describes the h/w, this needs to be described.
We absolutely need to describe the events. The topic here is how. -- Regards, Shawn