On 2022-02-25 21:13, Heiner Kallweit wrote:
Add a YAML schema binding for TM1628 auxdisplay
(7/11-segment LED) controller.
This patch is partially based on previous work from
Andreas Färber <afaerber@xxxxxxx>.
Co-developed-by: Andreas Färber <afaerber@xxxxxxx>
Signed-off-by: Andreas Färber <afaerber@xxxxxxx>
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
v5:
- add vendor prefix to driver-specific properties
---
.../bindings/auxdisplay/titanmec,tm1628.yaml | 92 +++++++++++++++++++
1 file changed, 92 insertions(+)
create mode 100644 Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
diff --git a/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
new file mode 100644
index 000000000..2a1ef692c
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/titanmec,tm1628.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Titan Micro Electronics TM1628 LED controller
+
+maintainers:
+ - Andreas Färber <afaerber@xxxxxxx>
+ - Heiner Kallweit <hkallweit1@xxxxxxxxx>
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+ compatible:
+ const: titanmec,tm1628
+
+ reg:
+ maxItems: 1
+
+ titanmec,grid:
+ description:
+ Mapping of display digit position to grid number.
+ This implicitly defines the display size.
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+ minItems: 1
+ maxItems: 7
+
+ titanmec,segment-mapping:
+ description:
+ Mapping of 7 segment display segments A-G to bit numbers 1-12.
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+ minItems: 7
+ maxItems: 7
+
+ "#address-cells":
+ const: 2
+
+ "#size-cells":
+ const: 0
+
+required:
+ - compatible
+ - reg
Would it be fair to say that "spi-lsb-first" and "spi-3wire" are also
required? The chips aren't configurable so won't exactly be usable any
other way. Furthermore I believe the transmission format actually works
out equivalent to SPI mode 3, so should warrant "spi-cpha" and
"spi-cpol" as well.
+
+patternProperties:
+ "^.*@[1-7],([1-9]|1[0-6])$":
+ type: object
+ $ref: /schemas/leds/common.yaml#
+ unevaluatedProperties: false
+ description: |
+ Properties for a single LED.
+
+ properties:
+ reg:
+ description: |
+ 1-based grid number, followed by 1-based segment bit number.
+ maxItems: 1
+
+ required:
+ - reg
I'm concerned that this leaves us no room to support the additional
keypad functionality in future. Having now double-checked a datasheet,
the inputs are also a two-dimensional mux (sharing the segment lines),
so the device effectively has two distinct but numerically-overlapping
child address spaces - one addressed by (grid,segment) and the other by
(segment,key).
Rob, Krysztof, any thoughts on the best DT idiom to leave accommodation
for that? I'm thinking either require an intermediate node to contain
each notional address space, or perhaps add another leading address cell
to select between them? I don't believe any of these things have further
functionality beyond that.
Thanks,
Robin.
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/leds/common.h>
+
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ led-controller@0 {
+ compatible = "titanmec,tm1628";
+ reg = <0>;
+ spi-3-wire;
+ spi-lsb-first;
+ spi-max-frequency = <500000>;
+ titanmec,grid = /bits/ 8 <4 3 2 1>;
+ titanmec,segment-mapping = /bits/ 8 <4 5 6 1 2 3 7>;
+ #address-cells = <2>;
+ #size-cells = <0>;
+
+ alarm@5,4 {
+ reg = <5 4>;
+ function = LED_FUNCTION_ALARM;
+ };
+ };
+ };
+...
