Hi Biju, On Mon, Jan 13, 2025 at 11:38 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > Hi Prabhakar, > > > -----Original Message----- > > From: Prabhakar <prabhakar.csengg@xxxxxxxxx> > > Sent: 13 January 2025 11:24 > > Subject: [PATCH v3 0/6] Add support to retrieve the bootstatus from watchdog for RZ/V2H(P) SoC > > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > > > Hi All, > > > > This patch series adds SYSCON support to retrieve boot status information for RZ/V2H(P) SoC. > > Summary of Changes, > > > > Clock: > > Add syscon compatible support to the CPG block in bindings and > > device trees. > > > > Watchdog: > > Document the renesas,r9a09g057-syscon-wdt-errorrst property. > > Update the watchdog driver to fetch and report boot status via > > Error Reset Registers (CPG_ERROR_RSTm). > > > > Device Tree: > > Add the syscon property to CPG and WDT nodes in R9A09G057 and > > R9A09G047 SoC DTSI. > > > > These changes enable the watchdog driver to identify boot sources like Power-on Reset and Watchdog > > Reset, improving system diagnostics. > > This means that, we should assume U-boot/bootloader should not clear the WDT reset status bit. > > If they clear it, there should be a way to propagate it from u-boot/bootloader to linux, > otherwise, we get wrong bootstatus in linux. > But the clearing of watchdog status by one of the cases: > > 1) u-boot identify the boot source and clear the status bit > I agree, if the tf-a/u-boot clears the register, the bootstatus reported by Linux will be in-correct. Alternative solution, would be: Let the TF-A create WDT nodes for us and add a property `renesas,r9a09g057-wdt-bootstatus` and propagate the WDT nodes to Linux. renesas,r9a09g057-wdt-bootstatus = <0/1>; 0 -> Power on reset 1 -> WDT reset Geert/Rob/Krzysztof - Is the proposed approach acceptable or is there any alternative where this can be avoided. Cheers, Prabhakar
