blk: add a helper function, blk_probe_or_unbind()

This function will be commonly used in block device drivers
in the succeeding patches.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 4ae8af6..a055387 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -672,6 +672,19 @@
 	return 0;
 }
 
+int blk_probe_or_unbind(struct udevice *dev)
+{
+	int ret;
+
+	ret = device_probe(dev);
+	if (ret) {
+		log_debug("probing %s failed\n", dev->name);
+		device_unbind(dev);
+	}
+
+	return ret;
+}
+
 int blk_unbind_all(int if_type)
 {
 	struct uclass *uc;
diff --git a/include/blk.h b/include/blk.h
index dde2173..133204a 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -371,6 +371,18 @@
 		       lbaint_t lba, struct udevice **devp);
 
 /**
+ * blk_probe_or_unbind() - Try to probe
+ *
+ * Try to probe the device, primarily for enumerating partitions.
+ * If it fails, the device itself is unbound since it means that it won't
+ * work any more.
+ *
+ * @dev:	The device to probe
+ * Return:	0 if OK, -ve on error
+ */
+int blk_probe_or_unbind(struct udevice *dev);
+
+/**
  * blk_unbind_all() - Unbind all device of the given interface type
  *
  * The devices are removed and then unbound.