Subject: [PATCH v4 32/47] serial: ucc_uart: use of_property_read_u32() in ucc_uart_probe()

From: Rasmus Villemoes <[email-masked]>
Date: Fri, 8 Nov 2019 14:01:08 +0100

For this to work correctly on little-endian hosts, don't access the
device-tree properties directly in native endianness, but use the
of_property_read_u32() helper.

Signed-off-by: Rasmus Villemoes <[email-masked]>
---
 drivers/tty/serial/ucc_uart.c | 41 +++++++++++++++--------------------
 1 file changed, 17 insertions(+), 24 deletions(-)

diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 313697842e24..f5ea84928a3b 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -1256,10 +1256,10 @@ static int soft_uart_init(struct platform_device *ofdev)
 static int ucc_uart_probe(struct platform_device *ofdev)
 {
 	struct device_node *np = ofdev->dev.of_node;
-	const unsigned int *iprop;      /* Integer OF properties */
 	const char *sprop;      /* String OF properties */
 	struct uart_qe_port *qe_port = NULL;
 	struct resource res;
+	u32 val;
 	int ret;
 
 	/*
@@ -1290,23 +1290,19 @@ static int ucc_uart_probe(struct platform_device *ofdev)
 
 	/* Get the UCC number (device ID) */
 	/* UCCs are numbered 1-7 */
-	iprop = of_get_property(np, "cell-index", NULL);
-	if (!iprop) {
-		iprop = of_get_property(np, "device-id", NULL);
-		if (!iprop) {
-			dev_err(&ofdev->dev, "UCC is unspecified in "
-				"device tree\n");
-			ret = -EINVAL;
-			goto out_free;
-		}
+	if (of_property_read_u32(np, "cell-index", &val) &&
+	    of_property_read_u32(np, "device-id", &val)) {
+		dev_err(&ofdev->dev, "UCC is unspecified in device tree\n");
+		ret = -EINVAL;
+		goto out_free;
 	}
 
-	if ((*iprop < 1) || (*iprop > UCC_MAX_NUM)) {
-		dev_err(&ofdev->dev, "no support for UCC%u\n", *iprop);
+	if (val < 1 || val > UCC_MAX_NUM) {
+		dev_err(&ofdev->dev, "no support for UCC%u\n", val);
 		ret = -ENODEV;
 		goto out_free;
 	}
-	qe_port->ucc_num = *iprop - 1;
+	qe_port->ucc_num = val - 1;
 
 	/*
 	 * In the future, we should not require the BRG to be specified in the
@@ -1350,13 +1346,12 @@ static int ucc_uart_probe(struct platform_device *ofdev)
 	}
 
 	/* Get the port number, numbered 0-3 */
-	iprop = of_get_property(np, "port-number", NULL);
-	if (!iprop) {
+	if (of_property_read_u32(np, "port-number", &val)) {
 		dev_err(&ofdev->dev, "missing port-number in device tree\n");
 		ret = -EINVAL;
 		goto out_free;
 	}
-	qe_port->port.line = *iprop;
+	qe_port->port.line = val;
 	if (qe_port->port.line >= UCC_MAX_UART) {
 		dev_err(&ofdev->dev, "port-number must be 0-%u\n",
 			UCC_MAX_UART - 1);
@@ -1386,31 +1381,29 @@ static int ucc_uart_probe(struct platform_device *ofdev)
 		}
 	}
 
-	iprop = of_get_property(np, "brg-frequency", NULL);
-	if (!iprop) {
+	if (of_property_read_u32(np, "brg-frequency", &val)) {
 		dev_err(&ofdev->dev,
 		       "missing brg-frequency in device tree\n");
 		ret = -EINVAL;
 		goto out_np;
 	}
 
-	if (*iprop)
-		qe_port->port.uartclk = *iprop;
+	if (val)
+		qe_port->port.uartclk = val;
 	else {
 		/*
 		 * Older versions of U-Boot do not initialize the brg-frequency
 		 * property, so in this case we assume the BRG frequency is
 		 * half the QE bus frequency.
 		 */
-		iprop = of_get_property(np, "bus-frequency", NULL);
-		if (!iprop) {
+		if (of_property_read_u32(np, "bus-frequency", &val)) {
 			dev_err(&ofdev->dev,
 				"missing QE bus-frequency in device tree\n");
 			ret = -EINVAL;
 			goto out_np;
 		}
-		if (*iprop)
-			qe_port->port.uartclk = *iprop / 2;
+		if (val)
+			qe_port->port.uartclk = val / 2;
 		else {
 			dev_err(&ofdev->dev,
 				"invalid QE bus-frequency in device tree\n");
-- 
2.23.0

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