[U-Boot] [PATCH v4 3/6] block: Add a function to find block device descriptor

[tien.fong.chee at intel.com]

From: Tien Fong Chee <tien.fong.chee at intel.com>

Add a function to find the block device descriptor of the parent
device.

Signed-off-by: Tien Fong Chee <tien.fong.chee at intel.com>
---
 drivers/block/blk-uclass.c | 23 +++++++++++++++++++++++
 include/blk.h              |  9 +++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 9e0c823..facf527 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -132,6 +132,29 @@ struct blk_desc *blk_get_devnum_by_typename(const char *if_typename, int devnum)
 }
 
 /**
+ * blk_get_by_device() - Get the block device descriptor for the given device
+ * @dev:	Instance of a storage device
+ *
+ * Return: With block device descriptor on success , NULL if there is no such
+ *	   block device.
+ */
+struct blk_desc *blk_get_by_device(struct udevice *dev)
+{
+	struct udevice *child_dev, *next;
+
+	device_foreach_child_safe(child_dev, next, dev) {
+		if (device_get_uclass_id(child_dev) != UCLASS_BLK)
+			continue;
+
+		return dev_get_uclass_platdata(child_dev);
+	}
+
+	debug("%s: No block device found\n", __func__);
+
+	return NULL;
+}
+
+/**
  * get_desc() - Get the block device descriptor for the given device number
  *
  * @if_type:	Interface type
diff --git a/include/blk.h b/include/blk.h
index 86f6d50..8ba9ab9 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -541,6 +541,15 @@ struct blk_desc *blk_get_devnum_by_typename(const char *if_typename,
 					    int devnum);
 
 /**
+ * blk_get_by_device() - Get the block device descriptor for the given device
+ * @dev:	Instance of a storage device
+ *
+ * Return: With block device descriptor on success , NULL if there is no such
+ *	   block device.
+ */
+struct blk_desc *blk_get_by_device(struct udevice *dev);
+
+/**
  * blk_dselect_hwpart() - select a hardware partition
  *
  * This selects a hardware partition (such as is supported by MMC). The block
-- 
2.2.0