Add DT bindings for an Hitachi HD44780 Character LCD Controller where its M6800 bus interface is connected to GPIOs.
Memory-mapped configurations are not yet supported. Signed-off-by: Geert Uytterhoeven <[email protected]> Cc: Rob Herring <[email protected]> Cc: Mark Rutland <[email protected]> Cc: [email protected] --- .../devicetree/bindings/auxdisplay/hit,hd44780.txt | 44 ++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt diff --git a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt new file mode 100644 index 0000000000000000..ee4054da458d412f --- /dev/null +++ b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt @@ -0,0 +1,44 @@ +DT bindings for the Hitachi HD44780 Character LCD Controller + +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. + +Required properties: + - compatible: Must contain "hit,hd44780", + - data-gpios: Must contain an array of either 4 or 8 GPIO specifiers, + referring to the GPIO pins connected to the data signal lines DB0-DB7 + (8-bit mode) or DB4-DB7 (4-bit mode) of the LCD Controller's bus interface, + - enable-gpios: Must contain a GPIO specifier, referring to the GPIO pin + connected to the "E" (Enable) signal line of the LCD Controller's bus + interface, + - rs-gpios: Must contain a GPIO specifier, referring to the GPIO pin + connected to the "RS" (Register Select) signal line of the LCD Controller's + bus interface, + - display-height: Height of the display, in character cells, + - display-width: Width of the display, in character cells. + +Optional properties: + - rw-gpios: Must contain a GPIO specifier, referring to the GPIO pin + connected to the "RW" (Read/Write) signal line of the LCD Controller's bus + interface, + - backlight-gpios: Must contain a GPIO specifier, referring to the GPIO pin + used for enabling the LCD's backlight, + - internal-buffer-width: Internal buffer width (default is 40 for displays + with 1 or 2 lines, and display-width for displays with more than 2 lines). + +Example: + + auxdisplay { + compatible = "hit,hd44780"; + + data-gpios = <&hc595 0 GPIO_ACTIVE_HIGH>, + <&hc595 1 GPIO_ACTIVE_HIGH>, + <&hc595 2 GPIO_ACTIVE_HIGH>, + <&hc595 3 GPIO_ACTIVE_HIGH>; + enable-gpios = <&hc595 4 GPIO_ACTIVE_HIGH>; + rs-gpios = <&hc595 5 GPIO_ACTIVE_HIGH>; + + display-height = <2>; + display-width = <16>; + }; -- 1.9.1
