On Tue, Sep 12, 2023 at 02:03:45PM +0300, Tony Lindgren wrote:
> Let's allow the userspace to find out the ttyS style name for a serial
> core port device if a tty exists. This can be done with:
>
> $ grep DEVNAME /sys/bus/serial-base/devices/*/tty/uevent
> /sys/bus/serial-base/devices/00:04:0.0/tty/uevent:DEVNAME=ttyS0
> /sys/bus/serial-base/devices/serial8250:0.1/tty/uevent:DEVNAME=ttyS1
> /sys/bus/serial-base/devices/serial8250:0.2/tty/uevent:DEVNAME=ttyS2
> /sys/bus/serial-base/devices/serial8250:0.3/tty/uevent:DEVNAME=ttyS3
>
> With this change, we can add /dev/serial/by-id symlinks for the serial
> core port device instances. This allows using hardware based port
> addressing in addition to the legacy ttyS style naming.
>
> The serial core port naming is DEVNAME:0.0, such as the 00:04:0.0 above.
> The 0.0 above are serial core controller id and port id. The port id and
> controller id are typically both zero unless the serial port hardware
> controller has multiple controllers or ports.
...
> + struct uart_match match = {port, drv};
A nit:
struct uart_match match = { .port = port, .driver = drv };
...
> + tty_dev = device_find_child(port->dev, &match, serial_match_port);
> + if (tty_dev) {
> + ret = sysfs_create_link(&port->port_dev->dev.kobj, &tty_dev->kobj,
> + "tty");
I would do it on a single line (you already over 80 anyway).
> + put_device(tty_dev);
> + if (ret)
> + goto err_remove_port;
> + }
...
> + struct uart_match match = {port, drv};
As per above.
...
> + tty_dev = device_find_child(port->dev, &match, serial_match_port);
Can be written as
tty_dev = device_find_child(phys_dev, &match, serial_match_port);
?
> + if (tty_dev) {
> + sysfs_remove_link(&port->port_dev->dev.kobj, "tty");
Can be written as
sysfs_remove_link(&port_dev->dev.kobj, "tty");
can't be?
> + put_device(tty_dev);
> + }
--
With Best Regards,
Andy Shevchenko
