| Message ID | 20210727140459.3767788-3-geert@linux-m68k.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | auxdisplay: ht16k33: Add character display support | expand |
On Tue, 27 Jul 2021 16:04:42 +0200, Geert Uytterhoeven wrote: > The Holtek HT16K33 LED controller is not only used for driving > dot-matrix displays, but also for driving segment displays. > > Document compatible values for the Adafruit 7-segment[1] and > 14-segment[2] FeatherWing expansion boards with red displays. According > to the schematics, all other Adafruit 7-segment and 14-segment display > backpack and FeatherWing expansion boards (including bare boards and > boards fitted with displays) are compatible with these two boards. > > [1] https://www.adafruit.com/product/3108 > [2] https://www.adafruit.com/product/3130 > > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > --- > v4: > - Combine compatible values for 7/14 segment displays into an enum, > > v3: > - Drop color property, > > v2: > - Fix type of color to uint32, > - "refresh-rate-hz" is still required for dot-matrix displays. > > Alternatives I considered: > 1. Document the attached display type in a child node. > I.e. specify segment type, number of characters, and wiring. > Especially the latter would become really complex, due to the sheer > amount of possible wiring combinations. > Using this method, you also loose the ability to just connect a > display to an i2c bus, and instantiate the device from sysfs, > without using DT: > > echo adafruit,3130 0x70 > /sys/class/i2c/i2c-adapter/.../new_device > > 2. Document all Adafruit 7-segment and 14-segment display backpack and > FeatherWing expansion boards. > This would lead to a myriad of compatible values: > > - items: > - enum: > - adafruit,878 # 0.56" 4-Digit 7-Segment Display Backpack (Red) > - adafruit,879 # 0.56" 4-Digit 7-Segment Display Backpack (Yellow) > - adafruit,880 # 0.56" 4-Digit 7-Segment Display Backpack (Green) > - adafruit,881 # 0.56" 4-Digit 7-Segment Display Backpack (Blue) > - adafruit,1002 # 0.56" 4-Digit 7-Segment Display Backpack (White) > - const: adafruit,877 # 0.56" 4-Digit 7-Segment Backpack > - const: holtek,ht16k33 > > - items: > - enum: > - adafruit,1268 # 1.2" 4-Digit 7-Segment Display Backpack (Green) > - adafruit,1269 # 1.2" 4-Digit 7-Segment Display Backpack (Yellow) > - adafruit,1270 # 1.2" 4-Digit 7-Segment Display Backpack (Red) > - const: adafruit,1271 # 1.2" 4-Digit 7-Segment Backpack > - const: holtek,ht16k33 > > - items: > - enum: > - adafruit,1911 # 0.54" Quad Alphanumeric Display Backpack (Red) > - adafruit,1912 # 0.54" Quad Alphanumeric Display Backpack (Blue) > - adafruit,2157 # 0.54" Quad Alphanumeric Display Backpack (White) > - adafruit,2158 # 0.54" Quad Alphanumeric Display Backpack (Yellow) > - adafruit,2159 # 0.54" Quad Alphanumeric Display Backpack (Yellow-Green) > - adafruit,2160 # 0.54" Quad Alphanumeric Display Backpack (Green) > - const: adafruit,1910 # 0.54" Quad 14-segment Alphanumeric Backpack > - const: holtek,ht16k33 > > - items: > - enum: > - adafruit,3106 # 0.56" 4-Digit 7-Segment FeatherWing Display (Blue) > - adafruit,3107 # 0.56" 4-Digit 7-Segment FeatherWing Display (Green) > - adafruit,3108 # 0.56" 4-Digit 7-Segment FeatherWing Display (Red) > - adafruit,3109 # 0.56" 4-Digit 7-Segment FeatherWing Display (White) > - adafruit,3110 # 0.56" 4-Digit 7-Segment FeatherWing Display (Yellow) > - const: adafruit,3088 # 0.56" 4-Digit 7-Segment FeatherWing > - const: holtek,ht16k33 > > - items: > - enum: > - adafruit,3127 # 0.54" Quad Alphanumeric FeatherWing Display (White) > - adafruit,3128 # 0.54" Quad Alphanumeric FeatherWing Display (Blue) > - adafruit,3129 # 0.54" Quad Alphanumeric FeatherWing Display (Green) > - adafruit,3130 # 0.54" Quad Alphanumeric FeatherWing Display (Red) > - adafruit,3131 # 0.54" Quad Alphanumeric FeatherWing Display (Yellow) > - adafruit,3132 # 0.54" Quad Alphanumeric FeatherWing Display (Yellow-Green) > - const: adafruit,3089 # 0.54" Quad 14-segment Alphanumeric FeatherWing > - const: holtek,ht16k33 > --- > .../bindings/auxdisplay/holtek,ht16k33.yaml | 20 ++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > Reviewed-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml index 64ffff460026040f..6baf1200c9d8488e 100644 --- a/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml +++ b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml @@ -14,14 +14,21 @@ allOf: properties: compatible: - const: holtek,ht16k33 + oneOf: + - items: + - enum: + - adafruit,3108 # 0.56" 4-Digit 7-Segment FeatherWing Display (Red) + - adafruit,3130 # 0.54" Quad Alphanumeric FeatherWing Display (Red) + - const: holtek,ht16k33 + + - const: holtek,ht16k33 # Generic 16*8 LED controller with dot-matrix display reg: maxItems: 1 refresh-rate-hz: maxItems: 1 - description: Display update interval in Hertz + description: Display update interval in Hertz for dot-matrix displays interrupts: maxItems: 1 @@ -44,7 +51,14 @@ properties: required: - compatible - reg - - refresh-rate-hz + +if: + properties: + compatible: + const: holtek,ht16k33 +then: + required: + - refresh-rate-hz additionalProperties: false
The Holtek HT16K33 LED controller is not only used for driving dot-matrix displays, but also for driving segment displays. Document compatible values for the Adafruit 7-segment[1] and 14-segment[2] FeatherWing expansion boards with red displays. According to the schematics, all other Adafruit 7-segment and 14-segment display backpack and FeatherWing expansion boards (including bare boards and boards fitted with displays) are compatible with these two boards. [1] https://www.adafruit.com/product/3108 [2] https://www.adafruit.com/product/3130 Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> --- v4: - Combine compatible values for 7/14 segment displays into an enum, v3: - Drop color property, v2: - Fix type of color to uint32, - "refresh-rate-hz" is still required for dot-matrix displays. Alternatives I considered: 1. Document the attached display type in a child node. I.e. specify segment type, number of characters, and wiring. Especially the latter would become really complex, due to the sheer amount of possible wiring combinations. Using this method, you also loose the ability to just connect a display to an i2c bus, and instantiate the device from sysfs, without using DT: echo adafruit,3130 0x70 > /sys/class/i2c/i2c-adapter/.../new_device 2. Document all Adafruit 7-segment and 14-segment display backpack and FeatherWing expansion boards. This would lead to a myriad of compatible values: - items: - enum: - adafruit,878 # 0.56" 4-Digit 7-Segment Display Backpack (Red) - adafruit,879 # 0.56" 4-Digit 7-Segment Display Backpack (Yellow) - adafruit,880 # 0.56" 4-Digit 7-Segment Display Backpack (Green) - adafruit,881 # 0.56" 4-Digit 7-Segment Display Backpack (Blue) - adafruit,1002 # 0.56" 4-Digit 7-Segment Display Backpack (White) - const: adafruit,877 # 0.56" 4-Digit 7-Segment Backpack - const: holtek,ht16k33 - items: - enum: - adafruit,1268 # 1.2" 4-Digit 7-Segment Display Backpack (Green) - adafruit,1269 # 1.2" 4-Digit 7-Segment Display Backpack (Yellow) - adafruit,1270 # 1.2" 4-Digit 7-Segment Display Backpack (Red) - const: adafruit,1271 # 1.2" 4-Digit 7-Segment Backpack - const: holtek,ht16k33 - items: - enum: - adafruit,1911 # 0.54" Quad Alphanumeric Display Backpack (Red) - adafruit,1912 # 0.54" Quad Alphanumeric Display Backpack (Blue) - adafruit,2157 # 0.54" Quad Alphanumeric Display Backpack (White) - adafruit,2158 # 0.54" Quad Alphanumeric Display Backpack (Yellow) - adafruit,2159 # 0.54" Quad Alphanumeric Display Backpack (Yellow-Green) - adafruit,2160 # 0.54" Quad Alphanumeric Display Backpack (Green) - const: adafruit,1910 # 0.54" Quad 14-segment Alphanumeric Backpack - const: holtek,ht16k33 - items: - enum: - adafruit,3106 # 0.56" 4-Digit 7-Segment FeatherWing Display (Blue) - adafruit,3107 # 0.56" 4-Digit 7-Segment FeatherWing Display (Green) - adafruit,3108 # 0.56" 4-Digit 7-Segment FeatherWing Display (Red) - adafruit,3109 # 0.56" 4-Digit 7-Segment FeatherWing Display (White) - adafruit,3110 # 0.56" 4-Digit 7-Segment FeatherWing Display (Yellow) - const: adafruit,3088 # 0.56" 4-Digit 7-Segment FeatherWing - const: holtek,ht16k33 - items: - enum: - adafruit,3127 # 0.54" Quad Alphanumeric FeatherWing Display (White) - adafruit,3128 # 0.54" Quad Alphanumeric FeatherWing Display (Blue) - adafruit,3129 # 0.54" Quad Alphanumeric FeatherWing Display (Green) - adafruit,3130 # 0.54" Quad Alphanumeric FeatherWing Display (Red) - adafruit,3131 # 0.54" Quad Alphanumeric FeatherWing Display (Yellow) - adafruit,3132 # 0.54" Quad Alphanumeric FeatherWing Display (Yellow-Green) - const: adafruit,3089 # 0.54" Quad 14-segment Alphanumeric FeatherWing - const: holtek,ht16k33 --- .../bindings/auxdisplay/holtek,ht16k33.yaml | 20 ++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)