Hello Conor, Andrew,
On 3/1/2025 12:22 AM, Conor Dooley wrote:
On Thu, Feb 27, 2025 at 03:26:31PM -0600, Andrew Davis wrote:
On 2/27/25 2:22 PM, Chintan Vankar wrote:
DT-binding of reg-mux is defined in such a way that one need to provide
register offset and mask in a "mux-reg-masks" property and corresponding
register value in "idle-states" property. This constraint forces to define
these values in such a way that "mux-reg-masks" and "idle-states" must be
in sync with each other. This implementation would be more complex if
specific register or set of registers need to be configured which has
large memory space. Introduce a new property "mux-reg-masks-state" which
allow to specify offset, mask and value as a tuple in a single property.
Signed-off-by: Chintan Vankar <c-vankar@xxxxxx>
---
.../devicetree/bindings/mux/reg-mux.yaml | 29 +++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/mux/reg-mux.yaml b/Documentation/devicetree/bindings/mux/reg-mux.yaml
index dc4be092fc2f..a73c5efcf860 100644
--- a/Documentation/devicetree/bindings/mux/reg-mux.yaml
+++ b/Documentation/devicetree/bindings/mux/reg-mux.yaml
@@ -32,11 +32,36 @@ properties:
- description: pre-shifted bitfield mask
description: Each entry pair describes a single mux control.
- idle-states: true
+ idle-states:
+ description: Each entry describes mux register state.
+
+ mux-reg-masks-state:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ items:
+ items:
+ - description: register offset
+ - description: pre-shifted bitfield mask
+ - description: register value to be set
+ description: This property is an extension of mux-reg-masks which
+ allows specifying register offset, mask and register
+ value to be set in a single property.
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - reg-mux
+ - mmio-mux
These are the only two possible compatibles, is this "if" check needed?
Aye.
+ then:
+ properties:
+ mux-reg-masks: true
+ mux-reg-masks-state: true
You need one, but cannot have both, right? There should be some
way to describe that.
Also an example added below would be good.
From the example schema:
# if/then schema can be used to handle conditions on a property affecting
# another property. A typical case is a specific 'compatible' value changes the
# constraints on other properties.
#
# For multiple 'if' schema, group them under an 'allOf'.
#
# If the conditionals become too unweldy, then it may be better to just split
# the binding into separate schema documents.
allOf:
- if:
properties:
compatible:
contains:
const: vendor,soc2-ip
then:
required:
- foo-supply
else:
# If otherwise the property is not allowed:
properties:
foo-supply: false
What's missing from here is making one of the properties required,
so
oneOf:
- required:
- masks
- required:
- masks-state
Andrew
Thanks for reviewing this patch.
For the use-case we have following three rules to be followed:
1. "mux-reg-masks" and "mux-reg-masks-state" should be mutually
exclusive.
2. "mux-reg-masks-state" and "idle-states" should also be mutually
exclusive.
3. If "mux-reg-masks" is present then "idle-states" might or might not
be there.
For the above conditions I have tried to write a binding as:
allOf:
- not:
required: [mux-reg-masks, mux-reg-masks-state]
- if:
required: [mux-reg-masks-state]
then:
not:
required: [idle-states]
- if:
required: [mux-reg-masks]
then:
properties:
idle-states:
description: It can be present with mux-reg-masks, but not
required
It is passing dt_binding_check and dtbs_check against correct and
incorrect properties provided in device tree node.
Let me know if you find this correct.
Regards,
Chintan.
+ maxItems: 1
required:
- compatible
- - mux-reg-masks
- '#mux-control-cells'
additionalProperties: false
