On 21.03.2022 09:34, Krzysztof Kozlowski wrote: > On 18/03/2022 21:50, Robin Murphy wrote: >> 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. > > I think intermediate nodes - leds, keys - are more appropriate, because > it is self-describing. Additional address space number would require > decoding this "0" or "1" into LED/key. For complex devices - like PMICs > with regulators, RTC and clocks - we already have such patterns. > Then it's just the question who can implement such an intermediate node based on what has been done so far. > Best regards, > Best regards, > Krzysztof
