Re: [PATCH] dt-bindings: sifive: describe sifive-blocks versioning

From: Atish Patra
Date: Wed Nov 21 2018 - 20:33:06 EST


On 11/21/18 5:07 PM, Paul Walmsley wrote:

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>.

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
Signed-off-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
---

Hi Rob, please let me know if this document works with your
requirements, or if some changes are needed. - Paul

.../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..b899e5c6e00c
--- /dev/null
+++ b/Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt

It should be be under Documentation/devicetree/bindings/riscv/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/master/src/main/scala/devices/uart/UART.scala#L43
+
+Until these IP blocks (or IP integration) support version
+autodiscovery, the maintainers of these IP blocks intend to increment

/s/autodiscovery/auto discovery

+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";


Just for the sake of completion, should this document also specify what should be the style of any possible closed IP as well?

Regards,
Atish