Commit graph

152 commits

Author SHA1 Message Date
Simon Glass
a53f4a29ac fdt: Add fdtdec_find_aliases() to deal with alias nodes
Stephen Warren pointed out that we should use nodes whether or not they
have an alias in the /aliases section. The aliases section specifies the
order so far as it can, but is not essential. Operating without alisses
is useful when the enumerated order of nodes does not matter (admittedly
rare in U-Boot).

This is considerably more complex, and it is important to keep this
complexity out of driver code. This patch creates a function
fdtdec_find_aliases() which returns an ordered list of node offsets
for a particular compatible ID, taking account of alias nodes.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2012-03-29 08:12:47 +02:00
Simon Glass
b5220bc6ed fdt: add decode helper library
This library provides useful functions to drivers which want to use
the fdt to control their operation. Functions are provided to:

- look up and enumerate a device type (for example assigning i2c bus 0,
     i2c bus 1, etc.)
- decode basic types from the fdt, like addresses and integers

While this library is not strictly necessary, it helps to minimise the
changes to a driver, in order to make it work under fdt control. Less
code is required, and so the barrier to switch drivers over is lower.

Additional functions to read arrays and GPIOs could be made available
here also.

Signed-off-by: Simon Glass <sjg@chromium.org>
2011-10-26 21:39:40 +02:00