Some devices have children and want to press an existing inactive child
into service when needed. Add a function to help with this.
Signed-off-by: Simon Glass <s...@chromium.org>
---
drivers/core/device.c | 18 ++++++++++++++++++
include/dm/device.h | 15 +++++++++++++++
test/dm/core.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 64 insertions(+)
diff --git a/drivers/core/device.c b/drivers/core/device.c
index a9e5906e7cd..5176aa3f866 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -681,6 +681,24 @@ int device_find_next_child(struct udevice **devp)
return 0;
}
+int device_find_first_inactive_child(struct udevice *parent,
+ enum uclass_id uclass_id,
+ struct udevice **devp)
+{
+ struct udevice *dev;
+
+ *devp = NULL;
+ list_for_each_entry(dev, &parent->child_head, sibling_node) {
+ if (!device_active(dev) &&
+ device_get_uclass_id(dev) == uclass_id) {
+ *devp = dev;
+ return 0;
+ }
+ }
+
+ return -ENODEV;
+}
+
struct udevice *dev_get_parent(const struct udevice *child)
{
return child->parent;
diff --git a/include/dm/device.h b/include/dm/device.h
index f873fc66e12..847934425bb 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -519,6 +519,21 @@ int device_find_first_child(struct udevice *parent, struct
udevice **devp);
*/
int device_find_next_child(struct udevice **devp);
+/**
+ * device_find_first_inactive_child() - Find the first inactive child
+ *
+ * This is used to locate an existing child of a device which is of a given
+ * uclass.
+ *
+ * @parent: Parent device to search
+ * @uclass_id: Uclass to look for
+ * @devp: Returns device found, if any
+ * @return 0 if found, else -ENODEV
+ */
+int device_find_first_inactive_child(struct udevice *parent,
+ enum uclass_id uclass_id,
+ struct udevice **devp);
+
/**
* device_has_children() - check if a device has any children
*
diff --git a/test/dm/core.c b/test/dm/core.c
index c15a8406c09..260f6494a2e 100644
--- a/test/dm/core.c
+++ b/test/dm/core.c
@@ -870,3 +870,34 @@ static int dm_test_uclass_names(struct unit_test_state
*uts)
return 0;
}
DM_TEST(dm_test_uclass_names, DM_TESTF_SCAN_PDATA);
+
+static int dm_test_inactive_child(struct unit_test_state *uts)
+{
+ struct dm_test_state *dms = uts->priv;
+ struct udevice *parent, *dev1, *dev2;
+
+ /* Skip the behaviour in test_post_probe() */
+ dms->skip_post_probe = 1;
+
+ ut_assertok(uclass_first_device_err(UCLASS_TEST, &parent));
+
+ /*
+ * Create a child but do not activate it. Calling the function again
+ * should return the same child.
+ */
+ ut_asserteq(-ENODEV, device_find_first_inactive_child(parent,
+ UCLASS_TEST, &dev1));
+ ut_assertok(device_bind_ofnode(parent, DM_GET_DRIVER(test_drv),
+ "test_child", 0, ofnode_null(), &dev1));
+
+ ut_assertok(device_find_first_inactive_child(parent, UCLASS_TEST,
+ &dev2));
+ ut_asserteq_ptr(dev1, dev2);
+
+ ut_assertok(device_probe(dev1));
+ ut_asserteq(-ENODEV, device_find_first_inactive_child(parent,
+ UCLASS_TEST, &dev2));
+
+ return 0;
+}
+DM_TEST(dm_test_inactive_child, DM_TESTF_SCAN_PDATA);
--
2.19.0.605.g01d371f741-goog
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