serial: meson: make use of uart_port member mapsize

Member mapsize of struct uart_port is meant to store the resource size.
By using it we can get rid of meson_uart_res_size().
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/meson_uart.c

@@ -402,26 +402,11 @@ static int meson_uart_verify_port(struct uart_port *port,
 	return ret;
 }
 
-static int meson_uart_res_size(struct uart_port *port)
-{
-	struct platform_device *pdev = to_platform_device(port->dev);
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(port->dev, "cannot obtain I/O memory region");
-		return -ENODEV;
-	}
-
-	return resource_size(res);
-}
-
 static void meson_uart_release_port(struct uart_port *port)
 {
-	int size = meson_uart_res_size(port);
-
 	if (port->flags & UPF_IOREMAP) {
-		devm_release_mem_region(port->dev, port->mapbase, size);
+		devm_release_mem_region(port->dev, port->mapbase,
+					port->mapsize);
 		devm_iounmap(port->dev, port->membase);
 		port->membase = NULL;
 	}
@@ -429,12 +414,7 @@ static void meson_uart_release_port(struct uart_port *port)
 
 static int meson_uart_request_port(struct uart_port *port)
 {
-	int size = meson_uart_res_size(port);
-
-	if (size < 0)
-		return size;
-
-	if (!devm_request_mem_region(port->dev, port->mapbase, size,
+	if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
 				     dev_name(port->dev))) {
 		dev_err(port->dev, "Memory region busy\n");
 		return -EBUSY;
@@ -443,7 +423,7 @@ static int meson_uart_request_port(struct uart_port *port)
 	if (port->flags & UPF_IOREMAP) {
 		port->membase = devm_ioremap_nocache(port->dev,
 						     port->mapbase,
-						     size);
+						     port->mapsize);
 		if (port->membase == NULL)
 			return -ENOMEM;
 	}
@@ -641,6 +621,7 @@ static int meson_uart_probe(struct platform_device *pdev)
 	port->uartclk = clk_get_rate(clk);
 	port->iotype = UPIO_MEM;
 	port->mapbase = res_mem->start;
+	port->mapsize = resource_size(res_mem);
 	port->irq = res_irq->start;
 	port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
 	port->dev = &pdev->dev;