Hi Geert, Thanks for the feedback. > -----Original Message----- > Subject: Re: [PATCH 1/5] dt-bindings: dma: Document RZ/G2L bindings > > Hi Biju, > > On Fri, Jun 11, 2021 at 1:36 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > wrote: > > Document RZ/G2L DMAC bindings. > > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > Thanks for your patch! > > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/dma/renesas,rz-dmac.yaml > > @@ -0,0 +1,132 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2 > > +--- > > +$id: > > +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi > > +cetree.org%2Fschemas%2Fdma%2Frenesas%2Crz-dmac.yaml%23&data=04%7C > > +01%7Cbiju.das.jz%40bp.renesas.com%7C4b547e10cbe64b6f4d8508d92f2da0c0% > > +7C53d82571da1947e49cb4625a166a4a2a%7C0%7C0%7C637592695286846809%7CUnk > > +nown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haW > > +wiLCJXVCI6Mn0%3D%7C1000&sdata=5Jh%2FxPaia5ZOY0CrViQCcrNtzuDejp8wo > > +Nrx9iO0ht8%3D&reserved=0 > > +$schema: > > +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi > > +cetree.org%2Fmeta-schemas%2Fcore.yaml%23&data=04%7C01%7Cbiju.das. > > +jz%40bp.renesas.com%7C4b547e10cbe64b6f4d8508d92f2da0c0%7C53d82571da19 > > +47e49cb4625a166a4a2a%7C0%7C0%7C637592695286846809%7CUnknown%7CTWFpbGZ > > +sb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0% > > +3D%7C1000&sdata=5qQ1PljM3e4Bn4%2FjdldYUHRBQL3jArJgRIAdLnhJraw%3D& > > +amp;reserved=0 > > + > > +title: Renesas RZ/G2L DMA Controller > > + > > +maintainers: > > + - Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > + > > +allOf: > > + - $ref: "dma-controller.yaml#" > > + > > +properties: > > + compatible: > > + items: > > + - enum: > > + - renesas,dmac-r9a07g044 # RZ/G2{L,LC} > > Please use "renesas,r9a07g044-dmac". OK. Will change. > > + - const: renesas,rz-dmac > > Does this need many changes for RZ/A1H and RZ/A2M? It will work on both RZ/A1H and RZ/A2M. I have n't tested since I don't have the board. There is some difference in MID bit size. Other wise both identical. > > + renesas,rz-dmac-slavecfg: > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > + description: | > > + DMA configuration for a slave channel. Each channel must have an > array of > > + 3 items as below. > > + first item in the array is MID+RID > > Already in dmas. > > > + second item in the array is slave src or dst address > > As pointed out by Rob, already known by the slave driver. > > > + third item in the array is channel configuration value. > > What exactly is this? > Does the R-Car DMAC have this too? If yes, how does its driver handle it? On R-CAR DMAC, we have only MID + RID values. Where as here we have channel configuration value With different set of parameter as mentioned in Table 16.4. Please see Page 569, Table 16.4 On-Chip Module requests section. For eg:- as per Rob's suggestion, I have modelled the driver with the below entries in ALSA driver for playback/record use case. dmas = <&dmac 0x255 0x10049c18 CH_CFG(0x1,0x0,0x1,0x0,0x2,0x1,0x1,0x0)>, <&dmac 0x256 0x10049c1c CH_CFG(0x0,0x0,0x1,0x0,0x2,0x1,0x1,0x0)>; dma-names = "tx", "rx"; Using first parameter, it gets dmac channel. using second and third parameter it configures the channel. Regards, Biju > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux- > m68k.org > > In personal conversations with technical people, I call myself a hacker. > But when I'm talking to journalists I just say "programmer" or something > like that. > -- Linus Torvalds
