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authorSimon Glass <sjg@chromium.org>2017-05-27 11:37:17 -0600
committerJaehoon Chung <jh80.chung@samsung.com>2017-06-09 20:25:16 +0900
commit9f103b9cb5f8de4f196b5ef8f6ddb4749cd732ba (patch)
treea4f8dd89d5ec45049c7bc0c389ce59835e1bcb23 /drivers/block
parentfc69d472621b5c7513bcb8b4e1fe58ca8f5e035a (diff)
downloadu-boot-9f103b9cb5f8de4f196b5ef8f6ddb4749cd732ba.tar.gz
dm: blk: Add a way to obtain a block device from its parent
Many devices support a child block device (e.g. MMC, USB). Add a convenient way to get this device given the parent device. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/blk-uclass.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 6145675271..23f131b7ad 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -453,6 +453,32 @@ int blk_prepare_device(struct udevice *dev)
return 0;
}
+int blk_get_from_parent(struct udevice *parent, struct udevice **devp)
+{
+ struct udevice *dev;
+ enum uclass_id id;
+ int ret;
+
+ device_find_first_child(parent, &dev);
+ if (!dev) {
+ debug("%s: No block device found for parent '%s'\n", __func__,
+ parent->name);
+ return -ENODEV;
+ }
+ id = device_get_uclass_id(dev);
+ if (id != UCLASS_BLK) {
+ debug("%s: Incorrect uclass %s for block device '%s'\n",
+ __func__, uclass_get_name(id), dev->name);
+ return -ENOTBLK;
+ }
+ ret = device_probe(dev);
+ if (ret)
+ return ret;
+ *devp = dev;
+
+ return 0;
+}
+
int blk_find_max_devnum(enum if_type if_type)
{
struct udevice *dev;