void gserial_free_line(unsigned char port_num)
{
struct gs_port *port;
mutex_lock(&ports[port_num].lock);
if (WARN_ON(!ports[port_num].port)) {
mutex_unlock(&ports[port_num].lock);
return;
}
port = ports[port_num].port;
ports[port_num].port = NULL;
mutex_unlock(&ports[port_num].lock);
gserial_free_port(port);
tty_unregister_device(gs_tty_driver, port_num);
}
int gserial_alloc_line(unsigned char *line_num)
{
struct usb_cdc_line_coding coding;
struct device *tty_dev;
int ret;
int port_num;
coding.dwDTERate = cpu_to_le32(9600);
coding.bCharFormat = 8;
coding.bParityType = USB_CDC_NO_PARITY;
coding.bDataBits = USB_CDC_1_STOP_BITS;
for (port_num = 0; port_num < MAX_U_SERIAL_PORTS; port_num++) {
ret = gs_port_alloc(port_num, &coding);
if (ret == -EBUSY)
continue;
if (ret)
return ret;
break;
}
if (ret)
return ret;
/* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */
tty_dev = tty_port_register_device(&ports[port_num].port->port,
gs_tty_driver, port_num, NULL);
if (IS_ERR(tty_dev)) {
struct gs_port *port;
pr_err("%s: failed to register tty for port %d, err %ld\n",
__func__, port_num, PTR_ERR(tty_dev));
ret = PTR_ERR(tty_dev);
port = ports[port_num].port;
ports[port_num].port = NULL;
gserial_free_port(port);
goto err;
}
*line_num = port_num;
err:
return ret;
}
