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>
This commit is contained in:
Simon Glass 2014-10-13 23:41:50 -06:00
parent a8981d4f80
commit accd4b19b3
3 changed files with 25 additions and 1 deletions

View File

@ -232,7 +232,7 @@ static void device_free(struct udevice *dev)
}
}
int device_probe(struct udevice *dev)
int device_probe_child(struct udevice *dev, void *parent_priv)
{
struct driver *drv;
int size = 0;
@ -282,6 +282,8 @@ int device_probe(struct udevice *dev)
ret = -ENOMEM;
goto fail;
}
if (parent_priv)
memcpy(dev->parent_priv, parent_priv, size);
}
ret = device_probe(dev->parent);
@ -335,6 +337,11 @@ fail:
return ret;
}
int device_probe(struct udevice *dev)
{
return device_probe_child(dev, NULL);
}
int device_remove(struct udevice *dev)
{
struct driver *drv;

View File

@ -65,6 +65,19 @@ int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
*/
int device_probe(struct udevice *dev);
/**
* device_probe() - Probe a child device, activating it
*
* Activate a device so that it is ready for use. All its parents are probed
* first. The child is provided with parent data if parent_priv is not NULL.
*
* @dev: Pointer to device to probe
* @parent_priv: Pointer to parent data. If non-NULL then this is provided to
* the child.
* @return 0 if OK, -ve on error
*/
int device_probe_child(struct udevice *dev, void *parent_priv);
/**
* device_remove() - Remove a device, de-activating it
*

View File

@ -139,6 +139,10 @@ struct udevice_id {
* @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.