[PATCH] pinctrl: single: check function mask to be non-zero

[Dario Binacchi]

Otherwise it can generate a division by zero, which has an undefined
behavior.

Signed-off-by: Dario Binacchi <dario...@libero.it>
---

 drivers/pinctrl/pinctrl-single.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index 7e1c5bb0a5..ebb7602dde 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -335,6 +335,10 @@ static int single_configure_bits(struct udevice *dev,
        phys_addr_t reg;
        u32 offset, val, mask, bit_pos, val_pos, mask_pos, submask;
 
+       /* If function mask is null, needn't enable it. */
+       if (!pdata->mask)
+               return 0;
+
        npins_in_reg = pdata->width / priv->bits_per_pin;
        func = single_allocate_function(dev, count * npins_in_reg);
        if (IS_ERR(func))
@@ -469,6 +473,11 @@ static int single_probe(struct udevice *dev)
 
        priv->npins = size / (pdata->width / BITS_PER_BYTE);
        if (pdata->bits_per_mux) {
+               if (!pdata->mask) {
+                       dev_err(dev, "function mask needs to be non-zero\n");
+                       return -EINVAL;
+               }
+
                priv->bits_per_pin = fls(pdata->mask);
                priv->npins *= (pdata->width / priv->bits_per_pin);
        }
-- 
2.17.1