of: Add __of_device_is_status() and makes more generic status check

Linux Kernel has __of_device_is_available() / __of_device_is_fail(),
these are checking if the status was "okay" / "ok" / "fail" / "fail-".

Add more generic __of_device_is_status() function for these.

Signed-off-by: Kuninori Morimoto <[email protected]>
Tested-by: Yusuke Goda <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Geert Uytterhoeven <[email protected]>

Author: morimoto

drivers/of/base.c

@@ -415,15 +415,8 @@ int of_machine_is_compatible(const char *compat)
 }
 EXPORT_SYMBOL(of_machine_is_compatible);
 
-/**
- *  __of_device_is_available - check if a device is available for use
- *
- *  @device: Node to check for availability, with locks already held
- *
- *  Return: True if the status property is absent or set to "okay" or "ok",
- *  false otherwise
- */
-static bool __of_device_is_available(const struct device_node *device)
+static bool __of_device_is_status(const struct device_node *device,
+				  const char * const*strings)
 {
 	const char *status;
 	int statlen;
@@ -433,16 +426,45 @@ static bool __of_device_is_available(const struct device_node *device)
 
 	status = __of_get_property(device, "status", &statlen);
 	if (status == NULL)
-		return true;
+		return false;
 
 	if (statlen > 0) {
-		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
-			return true;
+		while (*strings) {
+			unsigned int len = strlen(*strings);
+
+			if ((*strings)[len - 1] == '-') {
+				if (!strncmp(status, *strings, len))
+					return true;
+			} else {
+				if (!strcmp(status, *strings))
+					return true;
+			}
+			strings++;
+		}
 	}
 
 	return false;
 }
 
+/**
+ *  __of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Return: True if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool __of_device_is_available(const struct device_node *device)
+{
+	static const char * const ok[] = {"okay", "ok", NULL};
+
+	if (!device)
+		return false;
+
+	return !__of_get_property(device, "status", NULL) ||
+		__of_device_is_status(device, ok);
+}
+
 /**
  *  of_device_is_available - check if a device is available for use
  *
@@ -474,16 +496,9 @@ EXPORT_SYMBOL(of_device_is_available);
  */
 static bool __of_device_is_fail(const struct device_node *device)
 {
-	const char *status;
-
-	if (!device)
-		return false;
-
-	status = __of_get_property(device, "status", NULL);
-	if (status == NULL)
-		return false;
+	static const char * const fail[] = {"fail", "fail-", NULL};
 
-	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
+	return __of_device_is_status(device, fail);
 }
 
 /**