On Sat, Jul 16, 2011 at 02:16:40PM -0500, Rob Herring wrote: > On 07/16/2011 09:40 AM, Shawn Guo wrote: > > On Sat, Jul 16, 2011 at 08:55:41PM +0800, Tabi Timur-B04825 wrote: > >> Arnd Bergmann wrote: > >>> 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. > > > >> 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 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
