On Thu, Mar 01, 2018 at 11:41:01AM -0800, Guenter Roeck wrote:
> On Thu, Mar 01, 2018 at 06:17:21PM +0000, Fabrizio Castro wrote:
> > On R-Car Gen2 and RZ/G1 the watchdog IP clock needs to be always ON,
> > on R-Car Gen3 we power the IP down during suspend.
> >
> > This commit adds suspend/resume support, so that the watchdog counting
> > "pauses" during suspend on all of the SoCs compatible with this driver
> > and on those we are now adding support for (R-Car Gen2 and RZ/G1).
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro@xxxxxxxxxxxxxx>
> > Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@xxxxxxxxxxxxxx>
>
> Usually, on resume, we just restart the watchdog, with the expectation in mind
> that there may be some delay in userspace before it gets to send the next ping.
> Presumably that is not a concern here, so
I didn't know that. Actually, I'd prefer that. Even less complexity. And
if it is even more consistent with the rest of the drivers...
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> > ---
> > v6->v7:
> > * backup and restore register RWTCNT instead of using rwdt_get_timeleft and
> > rwdt_set_timeleft
> >
> > drivers/watchdog/renesas_wdt.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
> > index 831ef83..024d54e 100644
> > --- a/drivers/watchdog/renesas_wdt.c
> > +++ b/drivers/watchdog/renesas_wdt.c
> > @@ -49,6 +49,7 @@ struct rwdt_priv {
> > void __iomem *base;
> > struct watchdog_device wdev;
> > unsigned long clk_rate;
> > + u16 time_left;
> > u8 cks;
> > };
> >
> > @@ -203,6 +204,30 @@ static int rwdt_remove(struct platform_device *pdev)
> > return 0;
> > }
> >
> > +static int __maybe_unused rwdt_suspend(struct device *dev)
> > +{
> > + struct rwdt_priv *priv = dev_get_drvdata(dev);
> > +
> > + if (watchdog_active(&priv->wdev)) {
> > + priv->time_left = readw(priv->base + RWTCNT);
> > + rwdt_stop(&priv->wdev);
> > + }
> > + return 0;
> > +}
> > +
> > +static int __maybe_unused rwdt_resume(struct device *dev)
> > +{
> > + struct rwdt_priv *priv = dev_get_drvdata(dev);
> > +
> > + if (watchdog_active(&priv->wdev)) {
> > + rwdt_start(&priv->wdev);
> > + rwdt_write(priv, priv->time_left, RWTCNT);
> > + }
> > + return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume);
> > +
> > /*
> > * This driver does also fit for R-Car Gen2 (r8a779[0-4]) WDT. However, for SMP
> > * to work there, one also needs a RESET (RST) driver which does not exist yet
> > @@ -218,6 +243,7 @@ static struct platform_driver rwdt_driver = {
> > .driver = {
> > .name = "renesas_wdt",
> > .of_match_table = rwdt_ids,
> > + .pm = &rwdt_pm_ops,
> > },
> > .probe = rwdt_probe,
> > .remove = rwdt_remove,
> > --
> > 2.7.4
> >
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