Hi Geert,
> Subject: Re: [PATCH v2 1/3] clk: renesas: rzg2l: Add support for watchdog
> reset selection
>
> Hi Biju,
>
> On Thu, Nov 18, 2021 at 5:01 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> wrote:
> > > Subject: Re: [PATCH v2 1/3] clk: renesas: rzg2l: Add support for
> > > watchdog reset selection On Wed, Nov 17, 2021 at 9:21 AM Biju Das
> > > <biju.das.jz@xxxxxxxxxxxxxx>
> > > wrote:
> > > > On the, next version I am planning to introduce the below code for
> > > > Reset selection based on device availability, instead of selecting
> > > > all the channels. Is it the right way to do ? please let me know.
> > > >
> > > > node = of_find_node_by_name (NULL, NULL, "watchdog@12800800"); if
> > > > (node && of_device_is_available(node) {
> > > > // set reset selection for that channel
> > > > of_node_put(node);
> > > > }
> > > >
> > > > node = of_find_node_by_name (NULL, NULL, "watchdog@12800c00"); if
> > > > (node && of_device_is_available(node) {
> > > > // set reset selection for that channel
> > > > of_node_put(node);
> > > > }
> > > >
> > > > node = of_find_node_by_name (NULL, NULL, "watchdog@12800400"); if
> > > > (node && of_device_is_available(node) {
> > > > // set reset selection for that channel
> > > > of_node_put(node);
> > > > }
> > >
> > > Matching on node names is very fragile.
> >
> > Agreed.
> >
> > And what if the watchdog node is
> > > enabled in DT, but the watchdog driver is not available?
> > We will just configure, but since there is no watch driver available.
> > I guess nothing will happen.
> >
> > > Moreover, this looks like it should not be controlled from the clock
> > > driver, but from the watchdog driver instead.
> >
> > I have referred configure option from reset driver for R-Car, where
> > WDT is configured in reset block as similar register is located in reset
> block rather the watchdog driver.
> >
> > May be I should not use Matching on node names, rather use bitmask of
> bits as you suggested.
> >
> > Please share your views.
>
> On R-Car Gen2 and RZ/G1 SoCs, this is indeed configured by the rcar-rst
> driver, because the support was added later. Initial R-Car
> Gen2 revisions had hardware quirks preventing proper operation.
> On R-Car Gen3 and other RZ/G2 SoCs, this is configured by the boot loader,
> and it would be great if new SoCs (R-Car V3U, R-Car S4-8, and RZ/G2L)
> would handle this the same way.
Agreed, will move to bootloader. On R-Car it is done in TF-A(bl2_plat_setup).
Will do the same for RZ/G2L as well.
Regards,
Biju
