| Message ID | 17fdba7aa0c8f356cfdc28792d228817030b152e.1495443015.git-series.s.trumtrar@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/22/2017 01:51 AM, 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. As these lines are > optional, use devm_reset_control_get_optional_shared. If the reset line > is not specified in the devicetree, the reset framework will just skip > deasserting and continue. > This way all users of the driver will continue to function without > any harm, even if the reset line is not specified in the devicetree. > > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> > Cc: Wim Van Sebroeck <wim@iguana.be> > Cc: Guenter Roeck <linux@roeck-us.net> > Cc: linux-watchdog@vger.kernel.org > Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/dw_wdt.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c > index 914da3a4d334..36be987ff9ef 100644 > --- a/drivers/watchdog/dw_wdt.c > +++ b/drivers/watchdog/dw_wdt.c > @@ -29,6 +29,7 @@ > #include <linux/of.h> > #include <linux/pm.h> > #include <linux/platform_device.h> > +#include <linux/reset.h> > #include <linux/watchdog.h> > > #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 +236,14 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) > goto out_disable_clk; > } > > + dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); > + if (IS_ERR(dw_wdt->rst)) { > + ret = PTR_ERR(dw_wdt->rst); > + goto out_disable_clk; > + } > + > + reset_control_deassert(dw_wdt->rst); > + > wdd = &dw_wdt->wdd; > wdd->info = &dw_wdt_ident; > wdd->ops = &dw_wdt_ops; > @@ -279,6 +289,7 @@ static int dw_wdt_drv_remove(struct platform_device *pdev) > struct dw_wdt *dw_wdt = platform_get_drvdata(pdev); > > watchdog_unregister_device(&dw_wdt->wdd); > + reset_control_assert(dw_wdt->rst); > clk_disable_unprepare(dw_wdt->clk); > > return 0; >
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 914da3a4d334..36be987ff9ef 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -29,6 +29,7 @@ #include <linux/of.h> #include <linux/pm.h> #include <linux/platform_device.h> +#include <linux/reset.h> #include <linux/watchdog.h> #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 +236,14 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) goto out_disable_clk; } + dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); + if (IS_ERR(dw_wdt->rst)) { + ret = PTR_ERR(dw_wdt->rst); + goto out_disable_clk; + } + + reset_control_deassert(dw_wdt->rst); + wdd = &dw_wdt->wdd; wdd->info = &dw_wdt_ident; wdd->ops = &dw_wdt_ops; @@ -279,6 +289,7 @@ static int dw_wdt_drv_remove(struct platform_device *pdev) struct dw_wdt *dw_wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&dw_wdt->wdd); + reset_control_assert(dw_wdt->rst); clk_disable_unprepare(dw_wdt->clk); return 0;