For IP blocks that are generated from the public, open-source sifive-blocks repository, describe the version numbering policy that its maintainers intend to use, upon request from Rob Herring <robh@xxxxxxxxxx>. Signed-off-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx> Signed-off-by: Paul Walmsley <paul@xxxxxxxxx> Reviewed-by: Palmer Dabbelt <palmer@xxxxxxxxxx> Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: Palmer Dabbelt <palmer@xxxxxxxxxx> Cc: Megan Wachs <megan@xxxxxxxxxx> Cc: Wesley Terpstra <wesley@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- This second version updates the example URL, requested by Rob Herring <robh+dt@xxxxxxxxxx>. .../sifive/sifive-blocks-ip-versioning.txt | 38 +++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt diff --git a/Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt b/Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt new file mode 100644 index 000000000000..beaa3b64084e --- /dev/null +++ b/Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt @@ -0,0 +1,38 @@ +DT compatible string versioning for SiFive open-source IP blocks + +This document describes the version specification for DT "compatible" +strings for open-source SiFive IP blocks. HDL for these IP blocks +can be found in this public repository: + +https://github.com/sifive/sifive-blocks + +IP block-specific DT compatible strings are contained within the HDL, +in the form "sifive,<ip-block-name><integer version number>". + +An example is "sifive,uart0" from: + +https://github.com/sifive/sifive-blocks/blob/v1.0/src/main/scala/devices/uart/UART.scala#L43 + +Until these IP blocks (or IP integration) support version +auto-discovery, the maintainers of these IP blocks intend to increment +the suffixed number in the compatible string whenever the software +interface to these IP blocks changes, or when the functionality of the +underlying IP blocks changes in a way that software should be aware of. + +Driver developers can use compatible string "match" values such as +"sifive,uart0" to indicate that their driver is compatible with the +register interface and functionality associated with the relevant +upstream sifive-blocks commits. It is expected that most drivers will +match on these IP block-specific compatible strings. + +DT data authors, when writing data for a particular SoC, should +continue to specify an SoC-specific compatible string value, such as +"sifive,fu540-c000-uart". This way, if SoC-specific +integration-specific bug fixes or workarounds are needed, the kernel +or other system software can match on this string to apply them. The +IP block-specific compatible string (such as "sifive,uart0") should +then be specified as a subsequent value. + +An example of this style: + + compatible = "sifive,fu540-c000-uart", "sifive,uart0"; -- 2.20.1
