On Mon, 10 Jan 2022 18:25:35 +0530, Rajeev Nandan wrote:
In most cases, the default values of DSI PHY tuning registers should be sufficient as they are fully optimized. However, in some cases where extreme board parasitics cause the eye shape to degrade, the override bits can be used to improve the signal quality.
The general guidelines for DSI PHY tuning include:
- High and moderate data rates may benefit from the drive strength and drive level tuning.
- Drive strength tuning will affect the output impedance and may be used for matching optimization.
- Drive level tuning will affect the output levels without affecting the impedance.
The clock and data lanes have a calibration circuitry feature. The drive strength tuning can be done by adjusting rescode offset for hstop/hsbot, and the drive level tuning can be done by adjusting the LDO output level for the HSTX drive.
Signed-off-by: Rajeev Nandan quic_rajeevny@quicinc.com
Changes in v2:
- More details in the commit text (Stephen Boyd)
- Use human understandable values (Stephen Boyd, Dmitry Baryshkov)
- Do not take values that are going to be unused (Dmitry Baryshkov)
.../bindings/display/msm/dsi-phy-10nm.yaml | 33 ++++++++++++++++++++++ 1 file changed, 33 insertions(+)
My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check' on your patch (DT_CHECKER_FLAGS is new in v5.13):
yamllint warnings/errors: ./Documentation/devicetree/bindings/display/msm/dsi-phy-10nm.yaml:63:54: [error] syntax error: mapping values are not allowed here (syntax)
dtschema/dtc warnings/errors: ./Documentation/devicetree/bindings/display/msm/dsi-phy-10nm.yaml: mapping values are not allowed in this context in "<unicode string>", line 63, column 54 make[1]: *** Deleting file 'Documentation/devicetree/bindings/display/msm/dsi-phy-10nm.example.dts' Traceback (most recent call last): File "/usr/local/bin/dt-extract-example", line 46, in <module> binding = yaml.load(open(args.yamlfile, encoding='utf-8').read()) File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/main.py", line 434, in load return constructor.get_single_data() File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/constructor.py", line 119, in get_single_data node = self.composer.get_single_node() File "_ruamel_yaml.pyx", line 706, in _ruamel_yaml.CParser.get_single_node File "_ruamel_yaml.pyx", line 724, in _ruamel_yaml.CParser._compose_document File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node File "_ruamel_yaml.pyx", line 891, in _ruamel_yaml.CParser._compose_mapping_node File "_ruamel_yaml.pyx", line 904, in _ruamel_yaml.CParser._parse_next_event ruamel.yaml.scanner.ScannerError: mapping values are not allowed in this context in "<unicode string>", line 63, column 54 make[1]: *** [Documentation/devicetree/bindings/Makefile:25: Documentation/devicetree/bindings/display/msm/dsi-phy-10nm.example.dts] Error 1 make[1]: *** Waiting for unfinished jobs.... /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/display/msm/dsi-phy-10nm.yaml: ignoring, error parsing file make: *** [Makefile:1413: dt_binding_check] Error 2
doc reference errors (make refcheckdocs):
See https://patchwork.ozlabs.org/patch/1577891
This check can fail if there are any dependencies. The base for a patch series is generally the most recent rc1.
If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date:
pip3 install dtschema --upgrade
Please check and re-submit.