Otherwise, the gpiolib autorequest feature will produce a WARN_ON():
WARNING: at drivers/gpio/gpiolib.c:101 0x8020ec6c()
autorequest GPIO-215
[...]
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@kernel.org>
        int ret;
 
        mtx1_wdt_device.gpio = pdev->resource[0].start;
+       ret = gpio_request_one(mtx1_wdt_device.gpio,
+                               GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
+       if (ret < 0) {
+               dev_err(&pdev->dev, "failed to request gpio");
+               return ret;
+       }
 
        spin_lock_init(&mtx1_wdt_device.lock);
        init_completion(&mtx1_wdt_device.stop);
                mtx1_wdt_device.queue = 0;
                wait_for_completion(&mtx1_wdt_device.stop);
        }
+
+       gpio_free(mtx1_wdt_device.gpio);
        misc_deregister(&mtx1_wdt_misc);
        return 0;
 }