On 09/10/2020 14.15, Vinod Koul wrote: >>> If for any any reason subsequent txn is for different direction, I would >>> expect that parameters are set again before prep_ calls >> >> But in DEV_TO_DEV? > > Do we support that :D > >> If we have two peripherals, both needs config: >> p1_config and p2_config >> >> What and how would one use the single peripheral_config? > > Since the config is implementation specific, I do not think it limits. > You may create > > struct peter_config { > struct p1_config; > struct p2_config; > }; The use case is: MEM -DMA-> P1 -DMA-> P2 or P2 -DMA-> P1 -DMA-> MEM or MEM -DMA-> P2 or P2 -DMA-> MEM or MEM -DMA-> P1 -DMA-> MEM How would the DMA guess what it should do? How would the independent P1 and P2 would know how to set up the config? >> >> If only one of them needs config, then sure, the driver can pin-point >> which one the single config might apply to. >> >> Or you chain the same type of peripheral and you would need different >> config for tx and rx? >> >> - Péter >> >> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. >> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki