dm: core: Allow parents to have platform data for their children

For buses it is common for parents to need to know the address of the child
on the bus, the bus speed to use for that child, and other information. This
can be provided in platform data attached to each child.

Add driver model support for this, including auto-allocation which can be
requested using a new property to specify the size of the data.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/test/dm/bus.c b/test/dm/bus.c
index abbaccff509..63c8a9f7385 100644
--- a/test/dm/bus.c
+++ b/test/dm/bus.c
@@ -9,11 +9,16 @@
 #include <dm/device-internal.h>
 #include <dm/root.h>
 #include <dm/test.h>
+#include <dm/uclass-internal.h>
 #include <dm/ut.h>
 #include <dm/util.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct dm_test_parent_platdata {
+	int count;
+};
+
 enum {
 	FLAG_CHILD_PROBED	= 10,
 	FLAG_CHILD_REMOVED	= -7,
@@ -62,6 +67,8 @@ U_BOOT_DRIVER(testbus_drv) = {
 	.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),
+	.per_child_platdata_auto_alloc_size =
+			sizeof(struct dm_test_parent_platdata),
 	.child_pre_probe = testbus_child_pre_probe,
 	.child_post_remove = testbus_child_post_remove,
 };
@@ -271,3 +278,77 @@ static int dm_test_bus_parent_ops(struct dm_test_state *dms)
 	return 0;
 }
 DM_TEST(dm_test_bus_parent_ops, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test that the bus can store platform data about each child */
+static int dm_test_bus_parent_platdata(struct dm_test_state *dms)
+{
+	struct dm_test_parent_platdata *plat;
+	struct udevice *bus, *dev;
+	int child_count;
+
+	/* Check that the bus has no children */
+	ut_assertok(uclass_find_device(UCLASS_TEST_BUS, 0, &bus));
+	device_find_first_child(bus, &dev);
+	ut_asserteq_ptr(NULL, dev);
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_BUS, 0, &bus));
+
+	for (device_find_first_child(bus, &dev), child_count = 0;
+	     dev;
+	     device_find_next_child(&dev)) {
+		/* Check that platform data is allocated */
+		plat = dev_get_parent_platdata(dev);
+		ut_assert(plat != NULL);
+
+		/*
+		 * Check that it is not affected by the device being
+		 * probed/removed
+		 */
+		plat->count++;
+		ut_asserteq(1, plat->count);
+		device_probe(dev);
+		device_remove(dev);
+
+		ut_asserteq_ptr(plat, dev_get_parent_platdata(dev));
+		ut_asserteq(1, plat->count);
+		ut_assertok(device_probe(dev));
+		child_count++;
+	}
+	ut_asserteq(3, child_count);
+
+	/* Removing the bus should also have no effect (it is still bound) */
+	device_remove(bus);
+	for (device_find_first_child(bus, &dev), child_count = 0;
+	     dev;
+	     device_find_next_child(&dev)) {
+		/* Check that platform data is allocated */
+		plat = dev_get_parent_platdata(dev);
+		ut_assert(plat != NULL);
+		ut_asserteq(1, plat->count);
+		child_count++;
+	}
+	ut_asserteq(3, child_count);
+
+	/* Unbind all the children */
+	do {
+		device_find_first_child(bus, &dev);
+		if (dev)
+			device_unbind(dev);
+	} while (dev);
+
+	/* Now the child platdata should be removed and re-added */
+	device_probe(bus);
+	for (device_find_first_child(bus, &dev), child_count = 0;
+	     dev;
+	     device_find_next_child(&dev)) {
+		/* Check that platform data is allocated */
+		plat = dev_get_parent_platdata(dev);
+		ut_assert(plat != NULL);
+		ut_asserteq(0, plat->count);
+		child_count++;
+	}
+	ut_asserteq(3, child_count);
+
+	return 0;
+}
+DM_TEST(dm_test_bus_parent_platdata, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);