iio: tsl2583: Fix division by a zero lux_val

The lux_val returned from tsl2583_get_lux can potentially be zero,
so check for this to avoid a division by zero and an overflowed
gain_trim_val.

Fixes clang scan-build warning:

drivers/iio/light/tsl2583.c:345:40: warning: Either the
condition 'lux_val<0' is redundant or there is division
by zero at line 345. [zerodivcond]

Fixes: ac4f6eee8fe8 ("staging: iio: TAOS tsl258x: Device driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
index 0f787bf..c9d8f07 100644 (file)
--- a/drivers/iio/light/tsl2583.c
+++ b/drivers/iio/light/tsl2583.c
@@ -341,6 +341,14 @@ static int tsl2583_als_calibrate(struct iio_dev *indio_dev)
                return lux_val;
        }
 
+       /* Avoid division by zero of lux_value later on */
+       if (lux_val == 0) {
+               dev_err(&chip->client->dev,
+                       "%s: lux_val of 0 will produce out of range trim_value\n",
+                       __func__);
+               return -ENODATA;
+       }
+
        gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target)
                        * chip->als_settings.als_gain_trim) / lux_val);
        if ((gain_trim_val < 250) || (gain_trim_val > 4000)) {