dm: core: Allow parents to pass data to children during probe
Buses sometimes want to pass data to their children when they are probed.
For example, a SPI bus may want to tell the slave device about the chip
select it is connected to.
Add a new function to permit the parent data to be supplied to the child.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/include/dm/device.h b/include/dm/device.h
index 160cd58..56862d3 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -139,6 +139,10 @@
* @per_child_auto_alloc_size: Each device can hold private data owned by
* its parent. If required this will be automatically allocated if this
* value is non-zero.
+ * TODO(sjg@chromium.org): I'm considering dropping this, and just having
+ * device_probe_child() pass it in. So far the use case for allocating it
+ * is SPI, but I found that unsatisfactory. Since it is here I will leave it
+ * until things are clearer.
* @ops: Driver-specific operations. This is typically a list of function
* pointers defined by the driver, to implement driver functions required by
* the uclass.