[PATCH v2 2/9] watchdog: msc313e: Avoid division by zero

[Tzung-Bi Shih <tzungbi@kernel.org>]

clk_get_rate() could return 0.  Avoid a division by zero panic.

Fixes: e9800b799464 ("watchdog: Add Mstar MSC313e WDT driver")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Simply browsed code under drivers/watchdog/, the following drivers also
use clk_get_rate() as a denominator directly:
- drivers/watchdog/digicolor_wdt.c
- drivers/watchdog/rtd119x_wdt.c
- drivers/watchdog/rzv2h_wdt.c

Let me know if you think we should fix them as well.
---
v2:
- New to the series.
---
 drivers/watchdog/msc313e_wdt.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c
index f69d66971c41..c3018b970164 100644
--- a/drivers/watchdog/msc313e_wdt.c
+++ b/drivers/watchdog/msc313e_wdt.c
@@ -97,6 +97,7 @@ static int msc313e_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct msc313e_wdt_priv *priv;
+	unsigned long rate;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -116,7 +117,10 @@ static int msc313e_wdt_probe(struct platform_device *pdev)
 	priv->wdev.ops = &msc313e_wdt_ops,
 	priv->wdev.parent = dev;
 	priv->wdev.min_timeout = MSC313E_WDT_MIN_TIMEOUT;
-	priv->wdev.max_timeout = U32_MAX / clk_get_rate(priv->clk);
+	rate = clk_get_rate(priv->clk);
+	if (!rate)
+		return -EINVAL;
+	priv->wdev.max_timeout = U32_MAX / rate;
 	priv->wdev.timeout = MSC313E_WDT_DEFAULT_TIMEOUT;
 
 	/* If the period is non-zero the WDT is running */
-- 
2.53.0