Message ID | 20200218143126.11361-1-peter.ujfalusi@ti.com (mailing list archive) |
---|---|
Headers | show |
Series | dmaengine: ti: k3-udma: Support for per channel atype | expand |
On 18-02-20, 16:31, Peter Ujfalusi wrote: > Hi, > > The series is on top of the 5.6 update patches: > https://lore.kernel.org/lkml/20200214091441.27535-1-peter.ujfalusi@ti.com/ > > UDMA channels have ATYPE property which tells UDMA on how to treat the pointers > within descriptors (and TRs). > The ATYPE defined for j721e are: > 0: pointers are physical addresses (no translation) > 1: pointers are intermediate addresses (PVU) > 2: pointers are virtual addresses (SMMU) > > When Linux is booting within a virtualized environment channels must have the > ATYPE configured correctly to be able to access memory (ATYPE == 0 is not > allowed). > The ATYPE can be different for channels and their ATYPE depends on which > endpoint they are servicing, but it is not hardwired. > > In order to be able to tell the driver the ATYPE for the channel we need to > extend the dma-cells in case the device is going to be used in virtualized > setup. > > Non virtualized setups can still use dma-cells == 1. > > If dma-cells == 2, then the UDMA node must have ti,udma-atype property which > is used for non slave channels (where no DT binding is exist for a channel). Applied, thanks