dm: blk: Rename get_desc() and make it externally visible

get_desc() can be useful outside blk-uclass.c. Let's change it to
an API and make it externally visible.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 8855138..c9f7d46 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -178,17 +178,7 @@
 	return NULL;
 }
 
-/**
- * get_desc() - Get the block device descriptor for the given device number
- *
- * @uclass_id:	Interface type
- * @devnum:	Device number (0 = first)
- * @descp:	Returns block device descriptor on success
- * Return: 0 on success, -ENODEV if there is no such device and no device
- * with a higher device number, -ENOENT if there is no such device but there
- * is one with a higher number, or other -ve on other error.
- */
-static int get_desc(enum uclass_id uclass_id, int devnum, struct blk_desc **descp)
+int blk_get_desc(enum uclass_id uclass_id, int devnum, struct blk_desc **descp)
 {
 	bool found_more = false;
 	struct udevice *dev;
@@ -240,7 +230,7 @@
 	int ret;
 
 	for (ok = 0, devnum = 0;; ++devnum) {
-		ret = get_desc(uclass_id, devnum, &desc);
+		ret = blk_get_desc(uclass_id, devnum, &desc);
 		if (ret == -ENODEV)
 			break;
 		else if (ret)
@@ -263,7 +253,7 @@
 	struct blk_desc *desc;
 	int ret;
 
-	ret = get_desc(uclass_id, devnum, &desc);
+	ret = blk_get_desc(uclass_id, devnum, &desc);
 	if (ret)
 		return ret;
 	if (desc->type == DEV_TYPE_UNKNOWN)
@@ -280,7 +270,7 @@
 	int i;
 
 	for (i = 0;; ++i) {
-		ret = get_desc(uclass_id, i, &desc);
+		ret = blk_get_desc(uclass_id, i, &desc);
 		if (ret == -ENODEV)
 			break;
 		else if (ret)
@@ -297,7 +287,7 @@
 	struct blk_desc *desc;
 	int ret;
 
-	ret = get_desc(uclass_id, devnum, &desc);
+	ret = blk_get_desc(uclass_id, devnum, &desc);
 	if (ret)
 		return ret;
 	printf("\nIDE device %d: ", devnum);
@@ -312,7 +302,7 @@
 	int ret;
 
 	printf("\nDevice %d: ", devnum);
-	ret = get_desc(uclass_id, devnum, &desc);
+	ret = blk_get_desc(uclass_id, devnum, &desc);
 	if (ret == -ENODEV || ret == -ENOENT) {
 		printf("unknown device\n");
 		return -ENODEV;
@@ -334,7 +324,7 @@
 	ulong n;
 	int ret;
 
-	ret = get_desc(uclass_id, devnum, &desc);
+	ret = blk_get_desc(uclass_id, devnum, &desc);
 	if (ret)
 		return ret;
 	n = blk_dread(desc, start, blkcnt, buffer);
@@ -350,7 +340,7 @@
 	struct blk_desc *desc;
 	int ret;
 
-	ret = get_desc(uclass_id, devnum, &desc);
+	ret = blk_get_desc(uclass_id, devnum, &desc);
 	if (ret)
 		return ret;
 	return blk_dwrite(desc, start, blkcnt, buffer);
diff --git a/include/blk.h b/include/blk.h
index bbff057..b453b5a 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -515,6 +515,18 @@
  */
 struct blk_desc *blk_get_by_device(struct udevice *dev);
 
+/**
+ * blk_get_desc() - Get the block device descriptor for the given device number
+ *
+ * @uclass_id:	Interface type
+ * @devnum:	Device number (0 = first)
+ * @descp:	Returns block device descriptor on success
+ * Return: 0 on success, -ENODEV if there is no such device and no device
+ * with a higher device number, -ENOENT if there is no such device but there
+ * is one with a higher number, or other -ve on other error.
+ */
+int blk_get_desc(enum uclass_id uclass_id, int devnum, struct blk_desc **descp);
+
 #else
 #include <errno.h>
 /*