[PATCH 3/3] watchdog: rzv2h: Avoid division by zero

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

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

Fixes: f6febd0a30b6 ("watchdog: Add Watchdog Timer driver for RZ/V2H(P)")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
 drivers/watchdog/rzv2h_wdt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/rzv2h_wdt.c b/drivers/watchdog/rzv2h_wdt.c
index 3b6abb66a1da..83540dd9a37b 100644
--- a/drivers/watchdog/rzv2h_wdt.c
+++ b/drivers/watchdog/rzv2h_wdt.c
@@ -278,6 +278,7 @@ static int rzv2h_wdt_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct rzv2h_wdt_priv *priv;
 	struct clk *count_clk;
+	unsigned long rate;
 	int ret;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -314,8 +315,12 @@ static int rzv2h_wdt_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, -EINVAL, "Invalid count source\n");
 	}
 
+	rate = clk_get_rate(count_clk);
+	if (!rate)
+		return dev_err_probe(dev, -EINVAL, "Invalid clock rate\n");
+
 	priv->wdev.max_hw_heartbeat_ms = (MILLI * priv->of_data->timeout_cycles *
-					  priv->of_data->cks_div) / clk_get_rate(count_clk);
+					  priv->of_data->cks_div) / rate;
 	dev_dbg(dev, "max hw timeout of %dms\n", priv->wdev.max_hw_heartbeat_ms);
 
 	ret = devm_pm_runtime_enable(dev);
-- 
2.53.0