Hi Biju,
On Mon, Jun 14, 2021 at 3:02 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > Subject: Re: [PATCH 4/5] arm64: dts: renesas: r9a07g044: Add DMAC support
> > On Fri, Jun 11, 2021 at 1:36 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > wrote:
> > > Add DMAC support to RZ/G2L SoC DT.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> >
> > Thanks for your patch!
> >
> > > --- a/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > +++ b/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > @@ -8,6 +8,10 @@
> > > #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > #include <dt-bindings/clock/r9a07g044-cpg.h>
> > >
> > > +#define CH_CFG(reqd, loen, hien, lvl, am, sds, dds, tm) \
> > > + ((((tm) << 22) | ((dds) << 16) | ((sds) << 12) | ((am) << 8) | \
> > > + ((lvl) << 6) | ((hien) << 5) | ((loen) << 4) | ((reqd) << 3))
> > > +& 0x004FF778)
> > > +
> >
> > I assume the above will be removed?
>
> Basically the macro simplifies the channel configuration values in Table 16.4 page 569 of the hardware manual.
>
> Client driver will use MID+RID, and pass (Src address or dest address along with the channel configuration values
> For configuring DMA channel.
>
> For eg:-
>
> ssi0: ssi@10049c00 {
> compatible = "renesas,r9a07g044-ssi",
> "renesas,rz-ssi";
> reg = <0 0x10049c00 0 0x400>;
> interrupts = <GIC_SPI 326 IRQ_TYPE_LEVEL_HIGH>,
> <GIC_SPI 327 IRQ_TYPE_EDGE_RISING>,
> <GIC_SPI 328 IRQ_TYPE_EDGE_RISING>;
> interrupt-names = "int", "rx", "tx";
> clocks = <&cpg CPG_MOD R9A07G044_CLK_SSI0>,
> <&audio_clk1>,
> <&audio_clk2>;
> clock-names = "ssi", "audio_clk1", "audio_clk2";
> resets = <&cpg R9A07G044_CLK_SSI0>;
> 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";
> power-domains = <&cpg>;
> #sound-dai-cells = <0>;
> status = "disabled";
> };
>
> Please let me know your thoughts on this.
How will this work with (existing) drivers?
E.g. drivers/tty/serial/sh-sci.c:sci_request_dma_chan() already knows the
source and destination addresses.
The other CHCFG bits may be new, though.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
