serial: altera_uart: Use of_property_read_u32 instead of open-coding it

Use of_property_read_u32 instead of of_get_property with return value
checks and endianness conversion. Also remove the !CONFIG_OF
implementation of altera_uart_get_of_uartclk as of_property_read_u32
will return a non-zero value for !CONFIG_OF.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/altera_uart.c

@@ -508,29 +508,6 @@ static struct uart_driver altera_uart_driver = {
 	.cons		= ALTERA_UART_CONSOLE,
 };
 
-#ifdef CONFIG_OF
-static int altera_uart_get_of_uartclk(struct platform_device *pdev,
-				      struct uart_port *port)
-{
-	int len;
-	const __be32 *clk;
-
-	clk = of_get_property(pdev->dev.of_node, "clock-frequency", &len);
-	if (!clk || len < sizeof(__be32))
-		return -ENODEV;
-
-	port->uartclk = be32_to_cpup(clk);
-
-	return 0;
-}
-#else
-static int altera_uart_get_of_uartclk(struct platform_device *pdev,
-				      struct uart_port *port)
-{
-	return -ENODEV;
-}
-#endif /* CONFIG_OF */
-
 static int altera_uart_probe(struct platform_device *pdev)
 {
 	struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
@@ -570,7 +547,8 @@ static int altera_uart_probe(struct platform_device *pdev)
 	if (platp)
 		port->uartclk = platp->uartclk;
 	else {
-		ret = altera_uart_get_of_uartclk(pdev, port);
+		ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+					   &port->uartclk);
 		if (ret)
 			return ret;
 	}