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Commit bd8766b1 authored by Sjoerd Simons's avatar Sjoerd Simons Committed by Greg Kroah-Hartman
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serial: pl010: Move uart_register_driver call to device probe 



uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically
happen during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with overlapping major/minor numbers are
included.

Signed-off-by: default avatarSjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1cf4a7ef

drivers/tty/serial/amba-pl010.c

+21 −10
Original line number Diff line number Diff line
@@ -697,6 +697,7 @@ static struct console amba_console = { 
#define AMBA_CONSOLE	NULL

#endif



static DEFINE_MUTEX(amba_reg_lock);

static struct uart_driver amba_reg = {

	.owner			= THIS_MODULE,

	.driver_name		= "ttyAM",
@@ -749,6 +750,19 @@ static int pl010_probe(struct amba_device *dev, const struct amba_id *id) 
	amba_ports[i] = uap;



	amba_set_drvdata(dev, uap);



	mutex_lock(&amba_reg_lock);

	if (!amba_reg.state) {

		ret = uart_register_driver(&amba_reg);

		if (ret < 0) {

			mutex_unlock(&amba_reg_lock);

			dev_err(uap->port.dev,

				"Failed to register AMBA-PL010 driver\n");

			return ret;

		}

	}

	mutex_unlock(&amba_reg_lock);



	ret = uart_add_one_port(&amba_reg, &uap->port);

	if (ret)

		amba_ports[i] = NULL;
@@ -760,12 +774,18 @@ static int pl010_remove(struct amba_device *dev) 
{

	struct uart_amba_port *uap = amba_get_drvdata(dev);

	int i;

	bool busy = false;



	uart_remove_one_port(&amba_reg, &uap->port);



	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)

		if (amba_ports[i] == uap)

			amba_ports[i] = NULL;

		else if (amba_ports[i])

			busy = true;



	if (!busy)

		uart_unregister_driver(&amba_reg);



	return 0;

}
@@ -816,23 +836,14 @@ static struct amba_driver pl010_driver = { 


static int __init pl010_init(void)

{

	int ret;



	printk(KERN_INFO "Serial: AMBA driver\n");



	ret = uart_register_driver(&amba_reg);

	if (ret == 0) {

		ret = amba_driver_register(&pl010_driver);

		if (ret)

			uart_unregister_driver(&amba_reg);

	}

	return ret;

	return  amba_driver_register(&pl010_driver);

}



static void __exit pl010_exit(void)

{

	amba_driver_unregister(&pl010_driver);

	uart_unregister_driver(&amba_reg);

}



module_init(pl010_init);