dm: Introduce per-child data for devices

Some device types can have child devices and want to store information
about them. For example a USB flash stick attached to a USB host
controller would likely use this space. The controller can hold
information about the USB state of each of its children.

The data is stored attached to the child device in the 'parent_priv'
member. It can be auto-allocated by dm when the child is probed. To
do this, add a per_child_auto_alloc_size value to the parent driver.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/test/dm/bus.c b/test/dm/bus.c
index 08a4725648e..df8edcb37dd 100644
--- a/test/dm/bus.c
+++ b/test/dm/bus.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/device-internal.h>
 #include <dm/root.h>
 #include <dm/test.h>
 #include <dm/ut.h>
@@ -32,6 +33,7 @@ U_BOOT_DRIVER(testbus_drv) = {
 	.probe	= testbus_drv_probe,
 	.priv_auto_alloc_size = sizeof(struct dm_test_priv),
 	.platdata_auto_alloc_size = sizeof(struct dm_test_pdata),
+	.per_child_auto_alloc_size = sizeof(struct dm_test_parent_data),
 };
 
 UCLASS_DRIVER(testbus) = {
@@ -107,3 +109,66 @@ static int dm_test_bus_children_funcs(struct dm_test_state *dms)
 	return 0;
 }
 DM_TEST(dm_test_bus_children_funcs, 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)
+{
+	struct dm_test_parent_data *parent_data;
+	struct udevice *bus, *dev;
+	struct uclass *uc;
+	int value;
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_BUS, 0, &bus));
+
+	/* Check that parent data is allocated */
+	ut_assertok(device_find_child_by_seq(bus, 0, true, &dev));
+	ut_asserteq_ptr(NULL, dev_get_parentdata(dev));
+	ut_assertok(device_get_child_by_seq(bus, 0, &dev));
+	parent_data = dev_get_parentdata(dev);
+	ut_assert(NULL != parent_data);
+
+	/* Check that it starts at 0 and goes away when device is removed */
+	parent_data->sum += 5;
+	ut_asserteq(5, parent_data->sum);
+	device_remove(dev);
+	ut_asserteq_ptr(NULL, dev_get_parentdata(dev));
+
+	/* Check that we can do this twice */
+	ut_assertok(device_get_child_by_seq(bus, 0, &dev));
+	parent_data = dev_get_parentdata(dev);
+	ut_assert(NULL != parent_data);
+	parent_data->sum += 5;
+	ut_asserteq(5, parent_data->sum);
+
+	/* Add parent data to all children */
+	ut_assertok(uclass_get(UCLASS_TEST_FDT, &uc));
+	value = 5;
+	uclass_foreach_dev(dev, uc) {
+		/* Ignore these if they are not on this bus */
+		if (dev->parent != bus) {
+			ut_asserteq_ptr(NULL, dev_get_parentdata(dev));
+			continue;
+		}
+		ut_assertok(device_probe(dev));
+		parent_data = dev_get_parentdata(dev);
+
+		parent_data->sum = value;
+		value += 5;
+	}
+
+	/* Check it is still there */
+	value = 5;
+	uclass_foreach_dev(dev, uc) {
+		/* Ignore these if they are not on this bus */
+		if (dev->parent != bus)
+			continue;
+		parent_data = dev_get_parentdata(dev);
+
+		ut_asserteq(value, parent_data->sum);
+		value += 5;
+	}
+
+	return 0;
+}
+
+DM_TEST(dm_test_bus_parent_data, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);