[PATCH] serial: altera_uart: Scan for a free port if platform device id is -1
From: Tobias Klauser
Date: Mon Mar 28 2011 - 07:57:20 EST
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@xxxxxxxxx>
Cc: Anton Vorontsov <cbouatmailru@xxxxxxxxx>
Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx>
---
drivers/tty/serial/altera_uart.c | 26 +++++++++++++++-----------
1 files changed, 15 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 6a1ebd9..3a9cffa 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -517,11 +517,14 @@ 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;
@@ -564,6 +567,8 @@ 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;
@@ -571,14 +576,13 @@ 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;
}
--
1.7.0.4
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