hwmon: (ltc2992) Avoid division by zero

[ Upstream commit 10b0290 ]

Do not allow setting shunt resistor to 0. This results in a division by
zero when performing current value computations based on input voltages
and connected resistor values.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20231011135754.13508-1-antoniu.miclaus@analog.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/hwmon/ltc2992.c

@@ -875,8 +875,12 @@ static int ltc2992_parse_dt(struct ltc2992_state *st)
 		}
 
 		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
-		if (!ret)
+		if (!ret) {
+			if (!val)
+				return dev_err_probe(&st->client->dev, -EINVAL,
+						     "shunt resistor value cannot be zero\n");
 			st->r_sense_uohm[addr] = val;
+		}
 	}
 
 	return 0;