From: Wolfram Sang <wsa@the-dreams.de>
Date: Sun, 3 Apr 2016 21:32:00 +0000 (+0200)
Subject: i2c: jz4780: really prevent potential division by zero
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=caf280800aaf73f0796d1bb3fa0f6576c8222258;p=openwrt%2Fstaging%2Fblogic.git

i2c: jz4780: really prevent potential division by zero

Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Axel Lin <axel.lin@ingics.com>
---

diff --git a/drivers/i2c/busses/i2c-jz4780.c b/drivers/i2c/busses/i2c-jz4780.c
index f325663c27c5..ba14a863b451 100644
--- a/drivers/i2c/busses/i2c-jz4780.c
+++ b/drivers/i2c/busses/i2c-jz4780.c
@@ -771,11 +771,16 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 				   &clk_freq);
 	if (ret) {
-		dev_err(&pdev->dev, "clock-frequency not specified in DT");
+		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
 		goto err;
 	}
 
 	i2c->speed = clk_freq / 1000;
+	if (i2c->speed == 0) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
+		goto err;
+	}
 	jz4780_i2c_set_speed(i2c);
 
 	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);