On Oct 11, 2011, at 5:26 PM, Simon Glass wrote:
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
Changes in v2:
- Add example proposed decode helper library
Changes in v3:
- Simplify decode library to remove provide only primitive functions
- Remove i2c decode function
- Rename fdt_decode to fdtdec, since it will be used a lot
- Moved fdt_decode.c to /lib
- Export almost all functions from fdtdec, to allow widespread use
- Remove use of FDT_ERR_MISSING which is not strictly needed now
include/fdtdec.h | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++ lib/Makefile | 1 + lib/fdtdec.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 254 insertions(+), 0 deletions(-) create mode 100644 include/fdtdec.h create mode 100644 lib/fdtdec.c
I think this is the wrong approach. If we intend to go down the path of embedded a device tree we should look at produce a live tree structure that can be used like Linux has.
There are a lot of places we are manipulate device tree blobs that would be more efficient if we had a live tree structure in place.
I think that will only get worse with the addition of embedding a tree.
- k