watchdog: at91sam9: get and use slow clock
Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.
Get and use the slow clock as it is necessary for the at91sam9 watchdog.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index e4698f7..7e6acaf 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -17,6 +17,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -90,6 +91,7 @@
unsigned long heartbeat; /* WDT heartbeat in jiffies */
bool nowayout;
unsigned int irq;
+ struct clk *sclk;
};
/* ......................................................................... */
@@ -352,15 +354,25 @@
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);
+ wdt->sclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(wdt->sclk))
+ return PTR_ERR(wdt->sclk);
+
+ err = clk_prepare_enable(wdt->sclk);
+ if (err) {
+ dev_err(&pdev->dev, "Could not enable slow clock\n");
+ return err;
+ }
+
if (pdev->dev.of_node) {
err = of_at91wdt_init(pdev->dev.of_node, wdt);
if (err)
- return err;
+ goto err_clk;
}
err = at91_wdt_init(pdev, wdt);
if (err)
- return err;
+ goto err_clk;
platform_set_drvdata(pdev, wdt);
@@ -368,6 +380,11 @@
wdt->wdd.timeout, wdt->nowayout);
return 0;
+
+err_clk:
+ clk_disable_unprepare(wdt->sclk);
+
+ return err;
}
static int __exit at91wdt_remove(struct platform_device *pdev)
@@ -377,6 +394,7 @@
pr_warn("I quit now, hardware will probably reboot!\n");
del_timer(&wdt->timer);
+ clk_disable_unprepare(wdt->sclk);
return 0;
}