Hi Biju, On Sun, Dec 15, 2024 at 9:15 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > Hi Prabhakar, > > > -----Original Message----- > > From: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx> > > Sent: 14 December 2024 21:36 > > Subject: Re: [RFC PATCH] watchdog: rzv2h_wdt: Add support to retrieve the bootstatus information > > > > Hi Biju, > > > > On Sat, Dec 14, 2024 at 11:32 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > > > > > Hi Lad, Prabhakar, > > > > > <snip> > > > > > That is a change in behavior. Up to now the syscon phandle did not > > > > > have to exist for the driver to work. Is it guaranteed to not > > > > > result in regressions on systems where it doesn't ? Also, is this > > > > > documented ? I don't seem to be able to > > > > find it. > > > > > > > > > Agreed. I will add a fallback mechanism to handle cases where the > > > > syscon property is not present in the WDT node. This will ensure no > > > > regressions occur, and the bootstatus will simply be set to 0 in > > > > such scenarios. As mentioned in the patch comments, I have not yet > > > > submitted the DT binding changes because I wanted feedback on the syscon approach. The new RZ SoCs > > have registers scattered across various locations, and I was exploring if there might be a better way > > to handle this. > > > > > > See, syscon compatible not needed with [1] > > > > > > [1] > > > https://lore.kernel.org/all/20241211-syscon-fixes-v1-3-b5ac8c219e96@ke > > > rnel.org/ > > > > > As per my understanding, `syscon` compatible is required in this case because the CPG driver does not > > register a regmap. With the patch [1] (linked above), this applies to drivers that register a syscon > > regmap, where the corresponding DT node does not necessarily need a `syscon` compatible. > > I guess you can use "syscon_node_to_regmap" for that as of_syscon_register_regmap() is for externally > created regmaps?? > No, it doesn't work either; the CPG node block needs to have `syscon` compatible when you are using syscon_node_to_regmap/syscon_regmap_lookup_by_phandle. See patch [0] in `device_node_get_regmap()` the `of_syscon_register()` is only called when it has a `syscon` compatible or else `-EINVAL` is returned. [0] https://lore.kernel.org/all/20241211-syscon-fixes-v1-3-b5ac8c219e96@xxxxxxxxxx/ Cheers, Prabhakar
