On Fri, Jul 15, 2011 at 08:11:41PM +0200, Arnd Bergmann wrote: > On Friday 15 July 2011 18:45:38 Tabi Timur-B04825 wrote: > > > > On Fri, Jul 15, 2011 at 11:32 AM, Shawn Guo <[email protected]> wrote: > > > > > First of all, using powerpc dma-channel binding on such dma event > > > seems not reflecting the hardware facts. Secondly, the binding in > > > this case (below) looks silly. Thirdly, device driver need to make > > > code change for simply getting a dma event number. > > > > Take a look at p1022ds.dts or mpc8610hpcd.dts. We create separate DMA > > channel nodes on Freescale PowerPC parts because the channels really > > are independent. On these two boards, some of the DMA channels are > > used by the async DMA driver, and two of the channels are used by the > > audio driver. > > I think this is much better than using IORESOURCE_DMA fields, which > basically are only well-defined for PC-style i8237 DMA controllers > used in stuff like floppy drives and ISA sound cards. > > However, we should find a way to standardize finding the dma_chan > for an platform_device based on a phandle. Maybe a little helper > that will scan a well-known property (dma-channels?) for phandles > to a device_node that is backing a struct dma_chan.
That sounds appropriate. g. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
