iio: adc: ti-ads1298: prevent divide by zero in ads1298_set_samp_freq()

The "val" variable comes from the user so we need to ensure that it's not
zero.  In fact, all negative values are invalid as well.  Add a check for
that.

Fixes: 00ef7708fa60 ("iio: adc: ti-ads1298: Add driver")
Acked-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/c32c9087-86de-423b-8101-67b4a7f9d728@moroto.mountain
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.c
index 67637f1abdc745ca5256ab4146ce098f390d052a..1d1eaba3d6d129476ffe637240e64adb8929087e 100644 (file)
--- a/drivers/iio/adc/ti-ads1298.c
+++ b/drivers/iio/adc/ti-ads1298.c
@@ -258,6 +258,8 @@ static int ads1298_set_samp_freq(struct ads1298_private *priv, int val)
                rate = ADS1298_CLK_RATE_HZ;
        if (!rate)
                return -EINVAL;
+       if (val <= 0)
+               return -EINVAL;
 
        factor = (rate >> ADS1298_SHIFT_DR_HR) / val;
        if (factor >= BIT(ADS1298_SHIFT_DR_LP))