dm: core: Add functions for iterating through device children
Buses need to iterate through their children in some situations. Add a few
functions to make this easy.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt
index f9b68be..c435cdc 100644
--- a/doc/driver-model/README.txt
+++ b/doc/driver-model/README.txt
@@ -95,7 +95,7 @@
You should see something like this:
<...U-Boot banner...>
- Running 21 driver model tests
+ Running 22 driver model tests
Test: dm_test_autobind
Test: dm_test_autoprobe
Test: dm_test_bus_children
@@ -103,6 +103,7 @@
Device 'c-test@0': seq 0 is in use by 'a-test'
Device 'c-test@1': seq 1 is in use by 'd-test'
Test: dm_test_bus_children_funcs
+ Test: dm_test_bus_children_iterators
Test: dm_test_bus_parent_data
Test: dm_test_bus_parent_ops
Test: dm_test_children
diff --git a/drivers/core/device.c b/drivers/core/device.c
index 32e80e8..9538874 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -514,3 +514,30 @@
ret = device_find_child_by_of_offset(parent, seq, &dev);
return device_get_device_tail(dev, ret, devp);
}
+
+int device_find_first_child(struct udevice *parent, struct udevice **devp)
+{
+ if (list_empty(&parent->child_head)) {
+ *devp = NULL;
+ } else {
+ *devp = list_first_entry(&parent->child_head, struct udevice,
+ sibling_node);
+ }
+
+ return 0;
+}
+
+int device_find_next_child(struct udevice **devp)
+{
+ struct udevice *dev = *devp;
+ struct udevice *parent = dev->parent;
+
+ if (list_is_last(&dev->sibling_node, &parent->child_head)) {
+ *devp = NULL;
+ } else {
+ *devp = list_entry(dev->sibling_node.next, struct udevice,
+ sibling_node);
+ }
+
+ return 0;
+}
diff --git a/include/dm/device.h b/include/dm/device.h
index e08d496..160cd58 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -280,4 +280,22 @@
int device_get_child_by_of_offset(struct udevice *parent, int seq,
struct udevice **devp);
+/**
+ * device_find_first_child() - Find the first child of a device
+ *
+ * @parent: Parent device to search
+ * @devp: Returns first child device, or NULL if none
+ * @return 0
+ */
+int device_find_first_child(struct udevice *parent, struct udevice **devp);
+
+/**
+ * device_find_first_child() - Find the first child of a device
+ *
+ * @devp: Pointer to previous child device on entry. Returns pointer to next
+ * child device, or NULL if none
+ * @return 0
+ */
+int device_find_next_child(struct udevice **devp);
+
#endif
diff --git a/test/dm/bus.c b/test/dm/bus.c
index 873d64e42..abbaccf 100644
--- a/test/dm/bus.c
+++ b/test/dm/bus.c
@@ -140,6 +140,37 @@
}
DM_TEST(dm_test_bus_children_funcs, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+/* Test that we can iterate through children */
+static int dm_test_bus_children_iterators(struct dm_test_state *dms)
+{
+ struct udevice *bus, *dev, *child;
+
+ /* Walk through the children one by one */
+ ut_assertok(uclass_get_device(UCLASS_TEST_BUS, 0, &bus));
+ ut_assertok(device_find_first_child(bus, &dev));
+ ut_asserteq_str("c-test@5", dev->name);
+ ut_assertok(device_find_next_child(&dev));
+ ut_asserteq_str("c-test@0", dev->name);
+ ut_assertok(device_find_next_child(&dev));
+ ut_asserteq_str("c-test@1", dev->name);
+ ut_assertok(device_find_next_child(&dev));
+ ut_asserteq_ptr(dev, NULL);
+
+ /* Move to the next child without using device_find_first_child() */
+ ut_assertok(device_find_child_by_seq(bus, 5, true, &dev));
+ ut_asserteq_str("c-test@5", dev->name);
+ ut_assertok(device_find_next_child(&dev));
+ ut_asserteq_str("c-test@0", dev->name);
+
+ /* Try a device with no children */
+ ut_assertok(device_find_first_child(dev, &child));
+ ut_asserteq_ptr(child, NULL);
+
+ return 0;
+}
+DM_TEST(dm_test_bus_children_iterators,
+ DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
/* Test that the bus can store data about each child */
static int dm_test_bus_parent_data(struct dm_test_state *dms)
{