On 2021-03-22 15:48, 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.
Add a "color" property to support the different color variants.
[1] https://www.adafruit.com/product/3108
[2] https://www.adafruit.com/product/3130
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
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. Do not use the "color" property, but 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 | 22 ++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git
a/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
index 64ffff460026040f..4380a5177a67d2e2 100644
--- a/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
+++ b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
@@ -14,14 +14,23 @@ allOf:
properties:
compatible:
- const: holtek,ht16k33
+ oneOf:
+ - items:
+ - const: adafruit,3108 # 0.56" 4-Digit 7-Segment
FeatherWing Display (Red)
+ - const: holtek,ht16k33
+
+ - items:
+ - const: 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
The above should be included in patch 16
interrupts:
maxItems: 1
@@ -41,10 +50,17 @@ properties:
default: 16
description: Initial brightness level
+ color: true
+ description:
+ Color of the display. Use one of the LED_COLOR_ID_* prefixed
definitions
+ from the header include/dt-bindings/leds/common.h. The default
is red.
+ minimum: 0
+ maximum: 9
+ default: 1
+
The above should be included in patch 17
required:
- compatible
- reg
- - refresh-rate-hz
'refresh-rate-hz' is still a required property for the dot-matrix /
fbdev setup.
If it can no longer be listed here than maybe its nice to mention that
it's required
somewhere else (in it's description?).
Rob?
Groetjes / Kind regards,
Robin van der Gracht
