From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH v2 2/3] watchdog: dw_wdt: get reset lines from dt Date: Wed, 17 May 2017 09:32:59 +0200 Message-ID: <1495006379.3030.9.camel@pengutronix.de> References: <44e4e733055cfa2ed79091542c7bb17aa24afca9.1494595189.git-series.s.trumtrar@pengutronix.de> <4aa9252b45f2334eb429bb195d5d2963b4e61db1.1494595189.git-series.s.trumtrar@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4aa9252b45f2334eb429bb195d5d2963b4e61db1.1494595189.git-series.s.trumtrar-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steffen Trumtrar Cc: linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wim Van Sebroeck , Rob Herring , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, Dinh Nguyen , Guenter Roeck List-Id: devicetree@vger.kernel.org Hi Steffen, On Fri, 2017-05-12 at 15:34 +0200, Steffen Trumtrar wrote: > The dw_wdt has an external reset line, that can keep the device in reset > and therefore rendering it useless and also is the only way of stopping > the watchdog once it was started. > > Get the reset lines for this core from the devicetree. > If resets are not specified just warn but don't fail probing to be compatible > with all users. > > Signed-off-by: Steffen Trumtrar > Cc: Wim Van Sebroeck > Cc: Guenter Roeck > Cc: linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > --- > drivers/watchdog/dw_wdt.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c > index 914da3a4d334..3accddf1f381 100644 > --- a/drivers/watchdog/dw_wdt.c > +++ b/drivers/watchdog/dw_wdt.c > @@ -29,6 +29,7 @@ > #include > #include > #include > +#include > #include > > #define WDOG_CONTROL_REG_OFFSET 0x00 > @@ -54,6 +55,7 @@ struct dw_wdt { > struct clk *clk; > unsigned long rate; > struct watchdog_device wdd; > + struct reset_control *rst; > }; > > #define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd) > @@ -234,6 +236,8 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) > goto out_disable_clk; > } > > + dw_wdt->rst = devm_reset_control_get(&pdev->dev, NULL); > + This should be dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); if (IS_ERR(dw_wdt->rst)) return PTR_ERR(dw_wdt->rst); The optional variants return NULL if the reset is not specified in the DT. > wdd = &dw_wdt->wdd; > wdd->info = &dw_wdt_ident; > wdd->ops = &dw_wdt_ops; > @@ -267,6 +271,9 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) > if (ret) > goto out_disable_clk; > > + if (dw_wdt->rst) > + reset_control_deassert(dw_wdt->rst); > + This can be changed to reset_control_deassert(dw_wdt->rst); > return 0; > > out_disable_clk: Consider adding a call to reset_control_assert() in dw_wdt_drv_remove. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html