Thanks for the review.
On 2/5/23 23:41, Krzysztof Kozlowski wrote:
On 06/02/2023 00:02, Lars-Peter Clausen wrote:
The depth of the FIFO of the Cadence I2C controller IP is a synthesis
configuration parameter. Different instances of the IP can have different
values. For correct operation software needs to be aware of the size of the
FIFO.
Cannot this be inferred from compatible?
The compatible string currently encodes the version of the IP core. The
FIFO depth is an orthogonal setting. You could of course encode both the
version and FIFO depth as part of the compatible string. But you'd end
up with a combinatorial explosion of compatible strings. Like
cdns,i2c-r1p10-fifo-depth-2, ... cdns,i2c-r1p10-fifo-depth-16, ...,
cdns,i2c-r1p10-fifo-depth-256, cdns,i2c-r1p14-fifo-depth-2, ...
cdns,i2c-r1p14-fifo-depth-16, ..., cdns,i2c-r1p14-fifo-depth-256,
Add the documentation for the devicetree property that describes the FIFO
depth of the IP core.
The default value of 16 is for backwards compatibility reasons with
existing hardware descriptions where this property is not specified and
software has assumed that the FIFO depth is 16.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
index 2e95cda7262a..3daa2fa73257 100644
--- a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
+++ b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
@@ -38,6 +38,12 @@ properties:
description: |
Input clock name.
+ cdns,fifo-depth:
+ description:
+ Size of the data FIFO in words.
+ $ref: "/schemas/types.yaml#/definitions/uint32"
Drop quotes.
+ default: 16
maximum
minimum?
Will add a enum, since it has to be a power of two.
