hwmon: (f75375s) Disable setting DC fan control mode for F75373

F75373 does not support DC (linear voltage) fan control mode, so don't let
the user set it.

Cc: Riku Voipio <riku.voipio@iki.fi>
Reviewed-by: Bjoern Gerhart <oss@extracloud.de>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
index 9c3f078..35b570e 100644
--- a/drivers/hwmon/f75375s.c
+++ b/drivers/hwmon/f75375s.c
@@ -372,6 +372,10 @@
 	if (!(val == 0 || val == 1))
 		return -EINVAL;
 
+	/* F75373 does not support DC (linear voltage) fan control mode */
+	if (data->kind == f75373 && val == 0)
+		return -EINVAL;
+
 	mutex_lock(&data->update_lock);
 	conf = f75375_read8(client, F75375_REG_CONFIG1);
 	conf &= ~(1 << FAN_CTRL_LINEAR(nr));