[PATCH V2 2/6] tty: serial: meson: Request the register region in meson_uart_probe()

Yu Tu yu.tu at amlogic.com
Wed Dec 29 05:53:46 PST 2021


This simplifies resetting the UART controller during probe and will make
it easier to integrate the common clock code which will require the
registers at probe time as well.

Signed-off-by: Yu Tu <yu.tu at amlogic.com>
---
 drivers/tty/serial/meson_uart.c | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index c9a37602ffd0..99efe62a1507 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -397,24 +397,11 @@ static int meson_uart_verify_port(struct uart_port *port,
 
 static void meson_uart_release_port(struct uart_port *port)
 {
-	devm_iounmap(port->dev, port->membase);
-	port->membase = NULL;
-	devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
+	/* nothing to do */
 }
 
 static int meson_uart_request_port(struct uart_port *port)
 {
-	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;
-	}
-
-	port->membase = devm_ioremap(port->dev, port->mapbase,
-					     port->mapsize);
-	if (!port->membase)
-		return -ENOMEM;
-
 	return 0;
 }
 
@@ -728,6 +715,10 @@ static int meson_uart_probe(struct platform_device *pdev)
 	if (!port)
 		return -ENOMEM;
 
+	port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+
 	ret = meson_uart_probe_clocks(pdev, port);
 	if (ret)
 		return ret;
@@ -749,10 +740,7 @@ static int meson_uart_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, port);
 
 	/* reset port before registering (and possibly registering console) */
-	if (meson_uart_request_port(port) >= 0) {
-		meson_uart_reset(port);
-		meson_uart_release_port(port);
-	}
+	meson_uart_reset(port);
 
 	ret = uart_add_one_port(&meson_uart_driver, port);
 	if (ret)
-- 
2.33.1




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