1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 3322023e38aa..05c15ec7bd21 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -52,6 +52,8 @@
 #include <linux/scatterlist.h>
 #include <linux/delay.h>
 #include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/sizes.h>
 
@@ -1862,6 +1864,38 @@ static struct uart_driver amba_reg = {
         .cons                   = AMBA_CONSOLE,
 };
 
+static int pl011_probe_dt_alias(int index, struct device *dev)
+{
+        struct device_node *np;
+        static bool seen_dev_with_alias = false;
+        static bool seen_dev_without_alias = false;
+        int ret = index;
+
+        if (!IS_ENABLED(CONFIG_OF))
+                return ret;
+
+        np = dev->of_node;
+        if (!np)
+                return ret;
+
+        ret = of_alias_get_id(np, "serial");
+        if (IS_ERR_VALUE(ret)) {
+                seen_dev_without_alias = true;
+                ret = index;
+        } else {
+                seen_dev_with_alias = true;
+                if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) {
+                        dev_warn(dev, "requested serial port %d  not available.\n", ret);
+                        ret = index;
+                }
+        }
+
+        if (seen_dev_with_alias && seen_dev_without_alias)
+                dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n");
+
+        return ret;
+}
+
 static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 {
         struct uart_amba_port *uap;
@@ -1884,6 +1918,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
                 goto out;
         }
 
+        i = pl011_probe_dt_alias(i, &dev->dev);
+
         base = ioremap(dev->res.start, resource_size(&dev->res));
         if (!base) {
                 ret = -ENOMEM;