Hi John,
On Tue, 5 Aug 2025 at 10:27, John Madieu <john.madieu.xa@xxxxxxxxxxxxxx> wrote:
> > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > On Thu, 22 May 2025 at 20:23, John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> > wrote:
> > > The RZ/G3E SoC integrates a Temperature Sensor Unit (TSU) block
> > > designed to monitor the chip's junction temperature. This sensor is
> > > connected to channel 1 of the APB port clock/reset and provides
> > temperature measurements.
> > >
> > > It also requires calibration values stored in the system controller
> > > registers for accurate temperature measurement. Add a driver for the
> > Renesas RZ/G3E TSU.
> > >
> > > Signed-off-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> >
> > Thanks for your patch!
> >
> > The TSUs in RZ/V2H and RZ/V2N seem to be identical to the one in RZ/G3E.
> > However, RZ/V2H and RZ/V2N have two instances, while RZ/G3 has only one.
>
> This is true.
>
> > > --- /dev/null
> > > +++ b/drivers/thermal/renesas/rzg3e_thermal.c
> > > @@ -0,0 +1,443 @@
> >
> > > +/* SYS Trimming register offsets macro */ #define SYS_TSU_TRMVAL(x)
> > > +(0x330 + (x) * 4)
> >
> > RZ/V2H and RZ/V2N have a second set of trim values for the second TSU
> > instance. So I guess you want to specify the offset in DT instead.
>
> What do you think of 'renesas,tsu-channel' property or alike
> Property to specify the channel being used ?
While I agree instance IDs canbe useful (sometimes), the DT maintainers
do not like them very much, cfr. commit 6a57cf210711c068 ("docs: dt:
writing-bindings: Document discouraged instance IDs"), which prefers
cell/phandle arguments.
For this particular case:
1. The instance ID for the single TSU on RZ/G3E would be one, not zero
(oh, the SYS_LSI_OTPTSU1TRMVAL[01] register names do contain "TSU1"),
2. It will break the moment a new SoC is released that stores trim
values at different offsets in the SYSC block.
Hence a property containing a SYSC phandle and register offset sounds
better to me.
Thoughts?
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
