| Message ID | 1444632876-2672-5-git-send-email-wsa@the-dreams.de (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
Hi Wolfram, Thank you for the patch. On Monday 12 October 2015 07:54:35 Wolfram Sang wrote: > From: Wolfram Sang <wsa+renesas@sang-engineering.com> > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > --- > arch/arm/mach-shmobile/setup-rcar-gen2.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c > b/arch/arm/mach-shmobile/setup-rcar-gen2.c index > aa3339258d9c02..39976ae23a3df2 100644 > --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c > +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c > @@ -28,7 +28,18 @@ > #include "common.h" > #include "rcar-gen2.h" > > -#define MODEMR 0xe6160060 > +#define WDTRSTCR 0xe6160054 > +#define MODEMR 0xe6160060 > + > +void __init rcar_gen2_wdt_rst_init(void) > +{ > +#if defined(CONFIG_WATCHDOG) > + void __iomem *p = ioremap_nocache(WDTRSTCR, 4); > + BUG_ON(!p); > + iowrite32(0xa55a0000, p); > + iounmap(p); > +#endif That's a bit of a hack. We should aim at removing code from mach-shmobile, not adding new code :-) Furthermore it will cause issues with virtualization as hypervisors commonly map memory based on DT, the above code will thus generate a write access to an unmapped piece of memory as there's no corresponding DT node. Time for a reset driver it seems ;-) > +} > > u32 rcar_gen2_read_mode_pins(void) > { > @@ -128,6 +139,10 @@ void __init rcar_gen2_timer_init(void) > #endif /* CONFIG_ARM_ARCH_TIMER */ > > rcar_gen2_clocks_init(mode); > + > + /* allow watchdog timers to trigger reset */ > + rcar_gen2_wdt_rst_init(); > + > clocksource_of_init(); > }
> > +#if defined(CONFIG_WATCHDOG) > > + void __iomem *p = ioremap_nocache(WDTRSTCR, 4); > > + BUG_ON(!p); > > + iowrite32(0xa55a0000, p); > > + iounmap(p); > > +#endif > > That's a bit of a hack. We should aim at removing code from mach-shmobile, not > adding new code :-) Furthermore it will cause issues with virtualization as > hypervisors commonly map memory based on DT, the above code will thus generate > a write access to an unmapped piece of memory as there's no corresponding DT > node. I know. As I said in the cover letter (hint! ;)) it only works for me with UP on Lager. These arch patches are only to be able to test the driver. Totally not to be upstreamed. > Time for a reset driver it seems ;-) Can of worms for Gen2... Let's hope it will be easier on Gen3 and we can submit the main driver upstream this way.
Hi Wolfram, On Mon, Oct 12, 2015 at 8:54 AM, Wolfram Sang <wsa@the-dreams.de> wrote: > diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c > index aa3339258d9c02..39976ae23a3df2 100644 > --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c > +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c > @@ -28,7 +28,18 @@ > #include "common.h" > #include "rcar-gen2.h" > > -#define MODEMR 0xe6160060 > +#define WDTRSTCR 0xe6160054 > +#define MODEMR 0xe6160060 > + > +void __init rcar_gen2_wdt_rst_init(void) > +{ > +#if defined(CONFIG_WATCHDOG) > + void __iomem *p = ioremap_nocache(WDTRSTCR, 4); > + BUG_ON(!p); > + iowrite32(0xa55a0000, p); > + iounmap(p); > +#endif I think (most of) my comments from "Re: [RFC 4/5] ARM: shmobile: r8a7790: let rst module allow watchdog resets if desired" are still valid (http://www.spinics.net/lists/linux-sh/msg39799.html): | This is dangerous. If the xWDT was left running, the system will be | restarted soon. | | I think clearing the xWDT reset mask should be handled in the WDT driver | itself, when enabling the watchdog. | | As the wiring between WDT and reset controller differs on the various SoCs | (R-Car Gen2 uses the RST module, R-Mobile APE6 uses the SYSC module), | I was thinking about representing this into DT, e.g. adding a node for the RST: | | rst: reset-controller@e6160000 { | compatible = "renesas,rst-r8a7791", "syscon"; | reg = <0 0xe6160000 0 0x64>; | }; | | and adding a link to the RST to the wdt node: | | syscon = <&rst 0>; /* 0 for RWDT, 1 for SWDT */ | | On APE6 it can become a link to the SYSC instead. | [...] | On older SH-Mobile / R-Mobile, the link can be left out, as the reset is | not configurable on these SoCs, I think. However, the below is no longer true, as syscon no longer interferes with another driver for the same device: | It's slightly more complicated there, as we already have a driver for the | SYSC on R-Mobile (rmobile-reset), and a device node can't be bound | by both the syscon and the rmobile-reset driver. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org 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 -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c index aa3339258d9c02..39976ae23a3df2 100644 --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c @@ -28,7 +28,18 @@ #include "common.h" #include "rcar-gen2.h" -#define MODEMR 0xe6160060 +#define WDTRSTCR 0xe6160054 +#define MODEMR 0xe6160060 + +void __init rcar_gen2_wdt_rst_init(void) +{ +#if defined(CONFIG_WATCHDOG) + void __iomem *p = ioremap_nocache(WDTRSTCR, 4); + BUG_ON(!p); + iowrite32(0xa55a0000, p); + iounmap(p); +#endif +} u32 rcar_gen2_read_mode_pins(void) { @@ -128,6 +139,10 @@ void __init rcar_gen2_timer_init(void) #endif /* CONFIG_ARM_ARCH_TIMER */ rcar_gen2_clocks_init(mode); + + /* allow watchdog timers to trigger reset */ + rcar_gen2_wdt_rst_init(); + clocksource_of_init(); }