Sandbox supports block devices which can access files on the host machine.
At present there is no uclass for this. The devices are attached to the
root devic. The block-device type is therefore set to UCLASS_ROOT which
is confusing.

Block devices should be attached to a 'media' device instead, something
which handles access to the actual media and provides the block driver
for the block device.

Create a new uclass to handle this. It supports two operations, to attach
and detach a file on the host machine.

For now this is not fully plumbed in.

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

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, which is stored on
a dedicated partition. Add the metadata structure, and a driver model
uclass which provides functions to access the metadata. These are
generic API's, and implementations can be added based on parameters
like how the metadata partition is accessed and what type of storage
device houses the metadata.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

When probing a device fails NULL pointer is returned, and following
devices in uclass list cannot be iterated. Skip to next device on error
instead.

With that the only condition under which these simple iteration
functions return error is when the dm is not initialized at uclass_get
time. This is not all that interesting, change return type to void.

Fixes: 6494d708bf ("dm: Add base driver model support")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

device_probe returns early when the device is already activated.
Add a note to the documentation that it can be used on already activated
devices.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>

These functions use device_bind_with_driver_data internally, copy the
return value description.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>

Clarify documentation, fix a few more cases that could be broken by the
change.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>

Introduce UCLASS_MEMORY for future Memory Controller
device drivers.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

Update this function's comment and also the livetree documentation, so it
is clear when to use the function.

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

The _err variant iterators use the simple iterators without suffix as
basis.

However, there is no user that uclass_next_device_err for iteration,
many users of uclass_first_device_err use it to get the first and
(assumed) only device of an uclass, and a couple that use
uclass_next_device_err to get the device following a known device in the
uclass list.

While there are some truly singleton device classes in which more than
one device cannot exist these are quite rare, and most classes can have
multiple devices even if it is not the case on the SoC's EVB.

In a later patch the simple iterators will be updated to not stop on
error and return next device instead. With this in many cases the code
that expects the first device or an error if it fails to probe may get
the next device instead. Use the _check iterators as the basis of _err
iterators to preserve the old behavior.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

The return value is not used for anythig, and in a later patch the
behavior of the _err iterator will change in an incompatible way.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Update pvblock_probe() to avoid using internal var:
Signed-off-by: Simon Glass <sjg@chromium.org>