On Fri, Jun 26, 2020 at 10:25 AM Andrei Ziureaev <andrei.ziureaev@xxxxxxx> wrote: > > Currently, in yaml output, negative values are indistinguishable from > positive ones. Some bindings (for example > Documentation/devicetree/bindings/iio/accel/lis302.txt) mention negative > values. If those binding are converted to yaml, dt-schema validation > wouldn't work with them. > > The first patch is a mechanical change and shouldn't affect dtc's > behaviour. > > The second one is the functional change. When applied, dts to dts and > dts to yaml conversions preserve the '-' sign in front of integers. > > For now, in dts parsing, only the unary '-' operator creates negative > values (the other operators just set the 'is_negative' flag to false), > but it should be easy to add support for other operators if needed. > > One issue is that there are two ways to format an array of bytes in dts: > '/bits/ 8 <...>' and '[...]'. Only the former supports negative > integers. But, in dts output, only the latter is used. Therefore, I > didn't include support for negative 8-bit values in dts output (I did > add support for them in yaml output). Some possible alternatives are: > > - switch to the '/bits/ 8 <>' format in dts output IMO, we should do this which effectively deprecates the [] syntax. > > - only switch to the '/bits/ 8 <>' format if the array contains negative > values > > - add another marker to differentiate between the two formats > > Thanks, > Andrei. > > Andrei Ziureaev (3): > dtc: Turn 'uint64_t integer' into a struct > dtc: Preserve negative integers in yaml and dts output > dtc: Add sign preservation tests > > dtc-lexer.l | 10 +- > dtc-parser.y | 132 +++++++++++++++++++------- > dtc.h | 14 +++ > tests/run_tests.sh | 4 +- > tests/sign-preservation-bytes.dt.yaml | 5 + > tests/sign-preservation-bytes.dts | 7 ++ > tests/sign-preservation.dt.yaml | 20 ++++ > tests/sign-preservation.dts | 28 ++++++ > treesource.c | 35 +++++-- > yamltree.c | 32 ++++--- > 10 files changed, 225 insertions(+), 62 deletions(-) > create mode 100644 tests/sign-preservation-bytes.dt.yaml > create mode 100644 tests/sign-preservation-bytes.dts > create mode 100644 tests/sign-preservation.dt.yaml > create mode 100644 tests/sign-preservation.dts > > -- > 2.17.1 >
