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>
        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));