diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c index 6145675..23f131b 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; diff --git a/include/blk.h b/include/blk.h index a128ee4..4d60987 100644 --- a/include/blk.h +++ b/include/blk.h @@ -616,4 +616,11 @@ ulong blk_write_devnum(enum if_type if_type, int devnum, lbaint_t start, */ int blk_select_hwpart_devnum(enum if_type if_type, int devnum, int hwpart); +/** + * blk_get_from_parent() - obtain a block device by looking up its parent + * + * All devices with + */ +int blk_get_from_parent(struct udevice *parent, struct udevice **devp); + #endif diff --git a/test/dm/blk.c b/test/dm/blk.c index 5c5eb82..923e8d9 100644 --- a/test/dm/blk.c +++ b/test/dm/blk.c @@ -150,3 +150,21 @@ static int dm_test_blk_devnum(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_blk_devnum, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT); + +/* Test that we can get a block from its parent */ +static int dm_test_blk_get_from_parent(struct unit_test_state *uts) +{ + struct udevice *dev, *blk; + + ut_assertok(uclass_get_device(UCLASS_MMC, 0, &dev)); + ut_assertok(blk_get_from_parent(dev, &blk)); + + ut_assertok(uclass_get_device(UCLASS_I2C, 0, &dev)); + ut_asserteq(-ENOTBLK, blk_get_from_parent(dev, &blk)); + + ut_assertok(uclass_get_device(UCLASS_GPIO, 0, &dev)); + ut_asserteq(-ENODEV, blk_get_from_parent(dev, &blk)); + + return 0; +} +DM_TEST(dm_test_blk_get_from_parent, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);