serial: qcom-geni: Remove alias dependency from qcom serial driver

The absence of an alias in the device tree results in an invalid line
number, causing the driver probe to fail for GENI serial.

To prevent probe failures, dynamically assign line numbers if an alias is
not present in the device tree for non-console ports.

Signed-off-by: Viken Dadhaniya <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/qcom_geni_serial.c

···
 
 #define DMA_RX_BUF_SIZE		2048
 
+static DEFINE_IDA(port_ida);
+
 struct qcom_geni_device_data {
 	bool console;
 	enum geni_se_xfer_mode mode;
···
 	struct qcom_geni_serial_port *port;
 	int nr_ports = console ? GENI_UART_CONS_PORTS : GENI_UART_PORTS;
 
-	if (line < 0 || line >= nr_ports)
-		return ERR_PTR(-ENXIO);
+	if (console) {
+		if (line < 0 || line >= nr_ports)
+			return ERR_PTR(-ENXIO);
 
-	port = console ? &qcom_geni_console_port : &qcom_geni_uart_ports[line];
+		port = &qcom_geni_console_port;
+	} else {
+		int max_alias_num = of_alias_get_highest_id("serial");
+
+		if (line < 0 || line >= nr_ports)
+			line = ida_alloc_range(&port_ida, max_alias_num + 1, nr_ports, GFP_KERNEL);
+		else
+			line = ida_alloc_range(&port_ida, line, nr_ports, GFP_KERNEL);
+
+		if (line < 0)
+			return ERR_PTR(-ENXIO);
+
+		port = &qcom_geni_uart_ports[line];
+	}
 	return port;
 }
 
···
 						port->wakeup_irq);
 		if (ret) {
 			device_init_wakeup(&pdev->dev, false);
+			ida_free(&port_ida, uport->line);
 			uart_remove_one_port(drv, uport);
 			return ret;
 		}
···
 static void qcom_geni_serial_remove(struct platform_device *pdev)
 {
 	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
+	struct uart_port *uport = &port->uport;
 	struct uart_driver *drv = port->private_data.drv;
 
 	dev_pm_clear_wake_irq(&pdev->dev);
 	device_init_wakeup(&pdev->dev, false);
+	ida_free(&port_ida, uport->line);
 	uart_remove_one_port(drv, &port->uport);
 }