Hi Biju,
On Mon, 14 Apr 2025 at 18:04, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > On Thu, 20 Mar 2025 at 17:41, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > > Enable TCAN1046V-Q1 CAN Transceiver populated on RZ/G3E SMARC EVK by
> > > modelling it as two instances of tcan1042.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > ---
> > > v1->v2:
> > > * Replaced GPIO hog with CAN Transceiver.
> >
> > > --- a/arch/arm64/boot/dts/renesas/r9a09g047e57-smarc.dts
> > > +++ b/arch/arm64/boot/dts/renesas/r9a09g047e57-smarc.dts
> > > @@ -8,6 +8,8 @@
> > > /dts-v1/;
> > >
> > > /* Switch selection settings */
> > > +#define SW_GPIO8_CAN0_STB 0
> > > +#define SW_GPIO9_CAN1_STB 0
> > > #define SW_LCD_EN 0
> > > #define SW_PDM_EN 0
> > > #define SW_SD0_DEV_SEL 0
> > > @@ -42,16 +44,36 @@ &canfd {
> > > #if (!SW_PDM_EN)
> > > channel1 {
> > > status = "okay";
> > > +#if (!SW_LCD_EN) && (SW_GPIO9_CAN1_STB)
> > > + phys = <&can_transceiver1>; #endif
> > > };
> > > #endif
> >
> > Do you need these two levels of #ifdefs? If CAN-FD doesn't work without the transceivers, wouldn't
> > you just need a single #ifdef with the logical AND of all conditions above around the channel1
> > subnode?
>
> By default, the switch is set to GPIO8_PMOD, so, CAN_STB pulled low and the transceiver driver
> is not used.
>
> If any system(for eg: low power design) want to make use of STB, then change the SW
> and macro and then make use of transceiver driver.
[...]
> > Related, doesn't this need !SW_PDM_EN, too?
>
> SW_PDM_EN is only used for MUX between CAN1 Rx/Tx and PDM. It is not related
> to CAN0 Rx/Tx.
Thanks,
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
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
