We should guide people more strongly towards device tree to avoid the
proliferation of platform data structures. Add documentation to the driver
model README, and also the platform data header file.

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

The U_BOOT_DEVICE macro allows the declaration of a single U-Boot device.
Add an equivalent macro to declare an array of devices, for convenience.

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

The header files include/dm/platdata.h and include/dm/uclass.h
use ll_entry_declare(); therefore they depend on
include/linker_lists.h.

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

The struct udevice stands for a device, not a driver.
The driver_info.name is a driver's name, which is referenced
to bind devices.

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

Fix up the style of a few comments and add/clarify a few others.

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

Add driver model functionality for generic board.

This includes data structures and base code for registering devices and
uclasses (groups of devices with the same purpose, e.g. all I2C ports will
be in the same uclass).

The feature is enabled with CONFIG_DM.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: Viktor Křivák <viktor.krivak@gmail.com>
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>