watchdog: dw_wdt: get reset lines from dt (65a3b693) · Commits · 戴 / test

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: linux-watchdog@vger.kernel.org Reviewed-by:

Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by:

Guenter Roeck <linux@roeck-us.net> Signed-off-by:

Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/dw_wdt.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -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;

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