Re: [PATCH 1/2] dt-bindings: clock: document the fsl-sai driver

From: Michael Walle
Date: Thu Dec 05 2019 - 20:23:35 EST


Am 2019-12-05 16:16, schrieb Rob Herring:
On Sat, Nov 23, 2019 at 12:56:21AM +0100, Michael Walle wrote:
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
.../bindings/clock/fsl,sai-clock.yaml | 48 +++++++++++++++++++
1 file changed, 48 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml

diff --git a/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml b/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml
new file mode 100644
index 000000000000..7116c8bc24d3
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: GPL-2.0

Dual license new bindings please: (GPL-2.0-only OR BSD-2-Clause)

sure.


+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bindings/clock/fsl,sai-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale SAI bitclock-as-a-clock binding
+
+maintainers:
+ - Michael Walle <michael@xxxxxxxx>
+
+description: |
+ It is possible to use the BCLK pin of a SAI module as a generic clock
+ output. Some SoC are very constrained in their pin multiplexer
+ configuration. Eg. pins can only be changed groups. For example, on the
+ LS1028A SoC you can only enable SAIs in pairs. If you use only one SAI,
+ the second pins are wasted. Using this binding it is possible to use the
+ clock of the second SAI as a MCLK clock for an audio codec, for example.
+
+ This is a composite of a gated clock and a divider clock.
+
+properties:
+ compatible:
+ const: fsl,vf610-sai-clock
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 0
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - '#clock-cells'
+

Add:

additionalProperties: false

ok.

+examples:
+ - |
+ mclk: clock-mclk@f130080 {
+ compatible = "fsl,vf610-sai-clock";
+ reg = <0x0 0xf130080 0x0 0x80>;

Examples are built now and this will fail because the default
#address-cells and #size-cells are 1.

Mh, I've run the make dt_binding_check on this. It wasn't flagged,
but I guess thats because its interpreted as two resources.

I haven't found anything how you can change the default. Or do you
mean I should change the example to just use one address cell and
one size cell? But then how would that work for examples (on other
bindings) where there should be size-cells = <0> for example.


+ #clock-cells = <0>;
+ clocks = <&parentclk>;
+ };
--
2.20.1