serial: altera_uart: Scan for a free port if platform device id is -1

Devices extracted from device tree all seem to have pdev->id set to -1.
Up until now we mapped all devices with id -1 to the first device.  This
behaviour could lead to problems when using more than one Altera UART in
a system.

This patch changes the behaviour of the driver to scan for the next free
id in case the id is -1.

Because we cannot refer back to the assigned id in altera_uart_remove,
the port instance needs to be stored in device drvdata.

Reported-by: David Smoot <davidsmoot@gmail.com>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Tobias Klauser 2011-03-28 13:57:11 +02:00 committed by Greg Kroah-Hartman
parent 0259894c73
commit a664ec9675
1 changed files with 15 additions and 11 deletions

View File

@ -540,11 +540,14 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
int i = pdev->id;
int ret;
/* -1 emphasizes that the platform must have one port, no .N suffix */
if (i == -1)
i = 0;
/* if id is -1 scan for a free id and use that one */
if (i == -1) {
for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
if (altera_uart_ports[i].port.mapbase == 0)
break;
}
if (i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
return -EINVAL;
port = &altera_uart_ports[i].port;
@ -587,6 +590,8 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
port->ops = &altera_uart_ops;
port->flags = UPF_BOOT_AUTOCONF;
dev_set_drvdata(&pdev->dev, port);
uart_add_one_port(&altera_uart_driver, port);
return 0;
@ -594,14 +599,13 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
static int __devexit altera_uart_remove(struct platform_device *pdev)
{
struct uart_port *port;
int i = pdev->id;
struct uart_port *port = dev_get_drvdata(&pdev->dev);
if (i == -1)
i = 0;
port = &altera_uart_ports[i].port;
uart_remove_one_port(&altera_uart_driver, port);
if (port) {
uart_remove_one_port(&altera_uart_driver, port);
dev_set_drvdata(&pdev->dev, NULL);
port->mapbase = 0;
}
return 0;
}