dm: core: Allow uclasses to specify platdata for a device's children

In many cases the child platform data for a device's children is defined by
the uclass rather than the individual devices. For example, a SPI bus needs
to know the chip select and speed for each of its children. It makes sense
to allow this information to be defined the SPI uclass rather than each
individual driver.

If the device provides a size value for its child platdata, then use it.
Failng that, fall back to that provided by the uclass.

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

1 files changed, 30 insertions, 2 deletions

diff --git a/test/dm/bus.c b/test/dm/bus.c
index 63c8a9f..26b8293 100644
--- a/test/dm/bus.c
+++ b/test/dm/bus.c
@@ -279,8 +279,7 @@ static int dm_test_bus_parent_ops(struct dm_test_state *dms)
 }
 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)
+static int test_bus_parent_platdata(struct dm_test_state *dms)
 {
 	struct dm_test_parent_platdata *plat;
 	struct udevice *bus, *dev;
@@ -351,4 +350,33 @@ static int dm_test_bus_parent_platdata(struct dm_test_state *dms)
 
 	return 0;
 }
+
+/* Test that the bus can store platform data about each child */
+static int dm_test_bus_parent_platdata(struct dm_test_state *dms)
+{
+	return test_bus_parent_platdata(dms);
+}
 DM_TEST(dm_test_bus_parent_platdata, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* As above but the size is controlled by the uclass */
+static int dm_test_bus_parent_platdata_uclass(struct dm_test_state *dms)
+{
+	struct udevice *bus;
+	int size;
+	int ret;
+
+	/* Set the driver size to 0 so that the uclass size is used */
+	ut_assertok(uclass_find_device(UCLASS_TEST_BUS, 0, &bus));
+	size = bus->driver->per_child_platdata_auto_alloc_size;
+	bus->uclass->uc_drv->per_child_platdata_auto_alloc_size = size;
+	bus->driver->per_child_platdata_auto_alloc_size = 0;
+	ret = test_bus_parent_platdata(dms);
+	if (ret)
+		return ret;
+	bus->uclass->uc_drv->per_child_platdata_auto_alloc_size = 0;
+	bus->driver->per_child_platdata_auto_alloc_size = size;
+
+	return 0;
+}
+DM_TEST(dm_test_bus_parent_platdata_uclass,
+	DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);