mfd: cros_ec_dev: Register shutdown function for debugfs

Reboot or shutdown during delayed works could corrupt communication with
EC and certain I2C controller may not be able to recover from the error
state.

This patch registers a shutdown callback used to cancel the debugfs log
worker thread.
Signed-off-by: Daniel Hung-yu Wu <hywu@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/cros_ec_dev.c

@@ -472,6 +472,14 @@ static int ec_device_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void ec_device_shutdown(struct platform_device *pdev)
+{
+	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
+
+	/* Be sure to clear up debugfs delayed works */
+	cros_ec_debugfs_remove(ec);
+}
+
 static const struct platform_device_id cros_ec_id[] = {
 	{ DRV_NAME, 0 },
 	{ /* sentinel */ },
@@ -514,6 +522,7 @@ static struct platform_driver cros_ec_dev_driver = {
 	},
 	.probe = ec_device_probe,
 	.remove = ec_device_remove,
+	.shutdown = ec_device_shutdown,
 };
 
 static int __init cros_ec_dev_init(void)