Hi Biju,
On Wed, Jul 5, 2023 at 3:06 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > Subject: Re: [PATCH] arm64: dts: renesas: r9a07g0{4,5}4: Add support for
> > enabling MTU3
> > On Mon, Jul 3, 2023 at 3:29 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > wrote:
> > > Add support for MTU3 macro to enable MTU3 node on RZ/{G2,V2}L SMARC
> > EVK.
> > >
> > > The MTU3a PWM pins are muxed with spi1 pins and counter external input
> > > phase clock pins are muxed with scif2 pins. Disable these IPs when
> > > MTU3 macro is enabled.
> > >
> > > Apart from this, the counter Z phase clock signal is muxed with the
> > > SDHI1 cd signal. So disable SDHI1 IP, when the counter Z phase signal
> > > is enabled.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > --- a/arch/arm64/boot/dts/renesas/r9a07g044l2-smarc.dts
> > > +++ b/arch/arm64/boot/dts/renesas/r9a07g044l2-smarc.dts
> > > +&mtu3_pins {
> > > + mtu3-zphase-clk {
> > > + pinmux = <RZG2L_PORT_PINMUX(19, 0, 3)>; /* MTIOC1A */
> > > + };
> > > +};
> >
> > With the #defines moved up, mtu3-zphase-clk can be moved to mtu3_pins in
> > rzg2l-smarc-pinfunction.dtsi.
>
> Z-phase support is added only for cascade counter(MTU1 + MTU2)
>
> I thought by making this as optional, SDHI + standalone MTU1 or MTU2
> can still work. That is the reason it is moved here.
>
> If we move "mtu3-zphase-clk" to mtu3_pins in rzg2l-smarc-pinfunction.dtsi
> Either
>
> we need to make MTU3 mutually exclusive with SDHI
>
> Or
>
> Guard "mtu3-zphase-clk" with "MTU3_COUNTER_Z_PHASE_SIGNAL" macro in
> rzg2l-smarc-pinfunction.dtsi.
>
> Which one I need to select??
I'd go for the #ifdef, as you had above.
> > > +
> > > +&sdhi1 {
> > > + status = "disabled";
> > > +};
> > > +#endif /* MTU3_COUNTER_Z_PHASE_SIGNAL */
> >
> > BTW, how does the driver know it can use the counter Z phase clock
> > signal? I understand this can be either an input or output signal?
>
> It is an input signal and is supported only for the cascade(MTU1 + MTU2) operation. When we supply z-phase signal(By inserting SD card or applying a voltage to cd pin on the sd connector), counter value gets cleared.
The documentation for MTIOC1A says:
MTU1 TGRA input capture input/output compare output/PWM output pin
So the output functions are not yet supported by the driver?
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
