| Message ID | 20170216193053.5546-3-alexandre.belloni@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/16/2017 11:30 AM, Alexandre Belloni wrote: > When resuming for the deepest state on sama5d2, it is necessary to restore > MR as the registers are lost. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > --- > Changes in v2: > - cache mr beofre suspending > > drivers/watchdog/sama5d4_wdt.c | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c > index 2a60251806d2..5ddeb4803dc3 100644 > --- a/drivers/watchdog/sama5d4_wdt.c > +++ b/drivers/watchdog/sama5d4_wdt.c > @@ -28,6 +28,7 @@ > struct sama5d4_wdt { > struct watchdog_device wdd; > void __iomem *reg_base; > + u32 mr; Makes me wonder if we shouldn't just retain the original 'config' (and maybe rename it to 'mr). After all, it _is_ used now. > }; > > static int wdt_timeout = WDT_DEFAULT_TIMEOUT; > @@ -248,11 +249,42 @@ static const struct of_device_id sama5d4_wdt_of_match[] = { > }; > MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match); > > +#ifdef CONFIG_PM_SLEEP > +static int sama5d4_wdt_suspend(struct device *dev) > +{ > + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); > + > + wdt->mr = wdt_read(wdt, AT91_WDT_MR); > + Wouldn't you want to stop the watchdog here if it is running, ie set AT91_WDT_WDDIS ? > + return 0; > +} > + > +static int sama5d4_wdt_resume(struct device *dev) > +{ > + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); > + u32 reg; > + > + reg = wdt_read(wdt, AT91_WDT_MR); > + if (reg & AT91_WDT_WDDIS) > + wdt_write(wdt, AT91_WDT_MR, reg & ~AT91_WDT_WDDIS); > + > + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); Is that necessary ? Why not just write wdt->mr unconditionally ? > + if (wdt->mr & AT91_WDT_WDDIS) > + wdt_write(wdt, AT91_WDT_MR, wdt->mr); > + > + return 0; > +} > +#endif > + > +static SIMPLE_DEV_PM_OPS(sama5d4_wdt_pm_ops, sama5d4_wdt_suspend, > + sama5d4_wdt_resume); > + > static struct platform_driver sama5d4_wdt_driver = { > .probe = sama5d4_wdt_probe, > .remove = sama5d4_wdt_remove, > .driver = { > .name = "sama5d4_wdt", > + .pm = &sama5d4_wdt_pm_ops, > .of_match_table = sama5d4_wdt_of_match, > } > }; >
On 17/02/2017 at 06:47:03 -0800, Guenter Roeck wrote: > On 02/16/2017 11:30 AM, Alexandre Belloni wrote: > > When resuming for the deepest state on sama5d2, it is necessary to restore > > MR as the registers are lost. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > > --- > > Changes in v2: > > - cache mr beofre suspending > > > > drivers/watchdog/sama5d4_wdt.c | 32 ++++++++++++++++++++++++++++++++ > > 1 file changed, 32 insertions(+) > > > > diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c > > index 2a60251806d2..5ddeb4803dc3 100644 > > --- a/drivers/watchdog/sama5d4_wdt.c > > +++ b/drivers/watchdog/sama5d4_wdt.c > > @@ -28,6 +28,7 @@ > > struct sama5d4_wdt { > > struct watchdog_device wdd; > > void __iomem *reg_base; > > + u32 mr; > > Makes me wonder if we shouldn't just retain the original 'config' > (and maybe rename it to 'mr). After all, it _is_ used now. > > > }; > > > > static int wdt_timeout = WDT_DEFAULT_TIMEOUT; > > @@ -248,11 +249,42 @@ static const struct of_device_id sama5d4_wdt_of_match[] = { > > }; > > MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match); > > > > +#ifdef CONFIG_PM_SLEEP > > +static int sama5d4_wdt_suspend(struct device *dev) > > +{ > > + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); > > + > > + wdt->mr = wdt_read(wdt, AT91_WDT_MR); > > + > > Wouldn't you want to stop the watchdog here if it is running, > ie set AT91_WDT_WDDIS ? > Some existing customers want the watchdog to continue to run while the system is suspended. > > + return 0; > > +} > > + > > +static int sama5d4_wdt_resume(struct device *dev) > > +{ > > + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); > > + u32 reg; > > + > > + reg = wdt_read(wdt, AT91_WDT_MR); > > + if (reg & AT91_WDT_WDDIS) > > + wdt_write(wdt, AT91_WDT_MR, reg & ~AT91_WDT_WDDIS); > > + > > + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); > > Is that necessary ? Why not just write wdt->mr unconditionally ? > Because you can change WDV and WDD *OR* WDDIS but not both at the same time.
On 02/17/2017 07:22 AM, Alexandre Belloni wrote: > On 17/02/2017 at 06:47:03 -0800, Guenter Roeck wrote: >> On 02/16/2017 11:30 AM, Alexandre Belloni wrote: >>> When resuming for the deepest state on sama5d2, it is necessary to restore >>> MR as the registers are lost. >>> >>> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> >>> --- >>> Changes in v2: >>> - cache mr beofre suspending >>> >>> drivers/watchdog/sama5d4_wdt.c | 32 ++++++++++++++++++++++++++++++++ >>> 1 file changed, 32 insertions(+) >>> >>> diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c >>> index 2a60251806d2..5ddeb4803dc3 100644 >>> --- a/drivers/watchdog/sama5d4_wdt.c >>> +++ b/drivers/watchdog/sama5d4_wdt.c >>> @@ -28,6 +28,7 @@ >>> struct sama5d4_wdt { >>> struct watchdog_device wdd; >>> void __iomem *reg_base; >>> + u32 mr; >> >> Makes me wonder if we shouldn't just retain the original 'config' >> (and maybe rename it to 'mr). After all, it _is_ used now. >> >>> }; >>> >>> static int wdt_timeout = WDT_DEFAULT_TIMEOUT; >>> @@ -248,11 +249,42 @@ static const struct of_device_id sama5d4_wdt_of_match[] = { >>> }; >>> MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match); >>> >>> +#ifdef CONFIG_PM_SLEEP >>> +static int sama5d4_wdt_suspend(struct device *dev) >>> +{ >>> + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); >>> + >>> + wdt->mr = wdt_read(wdt, AT91_WDT_MR); >>> + >> >> Wouldn't you want to stop the watchdog here if it is running, >> ie set AT91_WDT_WDDIS ? >> > > Some existing customers want the watchdog to continue to run while the > system is suspended. > >>> + return 0; >>> +} >>> + >>> +static int sama5d4_wdt_resume(struct device *dev) >>> +{ >>> + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); >>> + u32 reg; >>> + >>> + reg = wdt_read(wdt, AT91_WDT_MR); >>> + if (reg & AT91_WDT_WDDIS) >>> + wdt_write(wdt, AT91_WDT_MR, reg & ~AT91_WDT_WDDIS); >>> + >>> + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); >> >> Is that necessary ? Why not just write wdt->mr unconditionally ? >> > > Because you can change WDV and WDD *OR* WDDIS but not both at the same > time. > Odd hardware ;-). Please add a comment explaining why the watchdog isn't stopped on suspend, and why the AT91_WDT_MR has to be reprogrammed on resume. Thanks, Guenter
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c index 2a60251806d2..5ddeb4803dc3 100644 --- a/drivers/watchdog/sama5d4_wdt.c +++ b/drivers/watchdog/sama5d4_wdt.c @@ -28,6 +28,7 @@ struct sama5d4_wdt { struct watchdog_device wdd; void __iomem *reg_base; + u32 mr; }; static int wdt_timeout = WDT_DEFAULT_TIMEOUT; @@ -248,11 +249,42 @@ static const struct of_device_id sama5d4_wdt_of_match[] = { }; MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match); +#ifdef CONFIG_PM_SLEEP +static int sama5d4_wdt_suspend(struct device *dev) +{ + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); + + wdt->mr = wdt_read(wdt, AT91_WDT_MR); + + return 0; +} + +static int sama5d4_wdt_resume(struct device *dev) +{ + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); + u32 reg; + + reg = wdt_read(wdt, AT91_WDT_MR); + if (reg & AT91_WDT_WDDIS) + wdt_write(wdt, AT91_WDT_MR, reg & ~AT91_WDT_WDDIS); + + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); + if (wdt->mr & AT91_WDT_WDDIS) + wdt_write(wdt, AT91_WDT_MR, wdt->mr); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(sama5d4_wdt_pm_ops, sama5d4_wdt_suspend, + sama5d4_wdt_resume); + static struct platform_driver sama5d4_wdt_driver = { .probe = sama5d4_wdt_probe, .remove = sama5d4_wdt_remove, .driver = { .name = "sama5d4_wdt", + .pm = &sama5d4_wdt_pm_ops, .of_match_table = sama5d4_wdt_of_match, } };
When resuming for the deepest state on sama5d2, it is necessary to restore MR as the registers are lost. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> --- Changes in v2: - cache mr beofre suspending drivers/watchdog/sama5d4_wdt.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)