i2c: sun6i-p2wi: Prevent potential division by zero

Make sure we don't OOPS in case clock-frequency is set to 0 in a DT. The
variable set here is later used as a divisor.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Author: AxelLin

drivers/i2c/busses/i2c-sun6i-p2wi.c

@@ -201,6 +201,11 @@ static int p2wi_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	if (clk_freq == 0) {
+		dev_err(dev, "clock-frequency is set to 0 in DT\n");
+		return -EINVAL;
+	}
+
 	if (of_get_child_count(np) > 1) {
 		dev_err(dev, "P2WI only supports one slave device\n");
 		return -EINVAL;