diff options
Diffstat (limited to 'Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml index 9222b06e93a0..fde07e4b119d 100644 --- a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml +++ b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml @@ -12,7 +12,10 @@ maintainers: description: The Hitachi HD44780 Character LCD Controller is commonly used on character LCDs that can display one or more lines of text. It exposes an M6800 bus - interface, which can be used in either 4-bit or 8-bit mode. + interface, which can be used in either 4-bit or 8-bit mode. By using a + GPIO expander it is possible to use the driver with one of the popular I2C + expander boards based on the PCF8574 available for these displays. For + an example see below. properties: compatible: @@ -94,3 +97,29 @@ examples: display-height-chars = <2>; display-width-chars = <16>; }; + - | + #include <dt-bindings/gpio/gpio.h> + i2c { + #address-cells = <1>; + #size-cells = <0>; + + pcf8574: pcf8574@27 { + compatible = "nxp,pcf8574"; + reg = <0x27>; + gpio-controller; + #gpio-cells = <2>; + }; + }; + hd44780 { + compatible = "hit,hd44780"; + display-height-chars = <2>; + display-width-chars = <16>; + data-gpios = <&pcf8574 4 0>, + <&pcf8574 5 0>, + <&pcf8574 6 0>, + <&pcf8574 7 0>; + enable-gpios = <&pcf8574 2 0>; + rs-gpios = <&pcf8574 0 0>; + rw-gpios = <&pcf8574 1 0>; + backlight-gpios = <&pcf8574 3 0>; + }; |