atmel_serial.c

		clk_put(atmel_port->clk);
		atmel_port->clk = NULL;
	}
err_clear_bit:
	clear_bit(atmel_port->uart.line, atmel_ports_in_use);
err:
	return ret;
}

/*
 * Even if the driver is not modular, it makes sense to be able to
 * unbind a device: there can be many bound devices, and there are
 * situations where dynamic binding and unbinding can be useful.
 *
 * For example, a connected device can require a specific firmware update
 * protocol that needs bitbanging on IO lines, but use the regular serial
 * port in the normal case.
 */
static int atmel_serial_remove(struct platform_device *pdev)
{
	struct uart_port *port = platform_get_drvdata(pdev);
	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
	int ret = 0;

	tasklet_kill(&atmel_port->tasklet_rx);
	tasklet_kill(&atmel_port->tasklet_tx);

	device_init_wakeup(&pdev->dev, 0);

	ret = uart_remove_one_port(&atmel_uart, port);

	kfree(atmel_port->rx_ring.buf);

	/* "port" is allocated statically, so we shouldn't free it */

	clear_bit(port->line, atmel_ports_in_use);

	clk_put(atmel_port->clk);
	atmel_port->clk = NULL;
	pdev->dev.of_node = NULL;

	return ret;
}

static struct platform_driver atmel_serial_driver = {
	.probe		= atmel_serial_probe,
	.remove		= atmel_serial_remove,
	.suspend	= atmel_serial_suspend,
	.resume		= atmel_serial_resume,
	.driver		= {
		.name			= "atmel_usart_serial",
		.of_match_table		= of_match_ptr(atmel_serial_dt_ids),
	},
};

static int __init atmel_serial_init(void)
{
	int ret;

	ret = uart_register_driver(&atmel_uart);
	if (ret)
		return ret;

	ret = platform_driver_register(&atmel_serial_driver);
	if (ret)
		uart_unregister_driver(&atmel_uart);

	return ret;
}
device_initcall(atmel_serial_init);