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dt-bindings: auxdisplay: Add bindings for Hitachi HD44780
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 <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
authored by
Geert Uytterhoeven
and committed by
Greg Kroah-Hartman
dd9502a9
1d3b2af2
+44
+44
Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt
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Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt
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DT bindings for the Hitachi HD44780 Character LCD Controller
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The Hitachi HD44780 Character LCD Controller is commonly used on character LCDs
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that can display one or more lines of text. It exposes an M6800 bus interface,
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which can be used in either 4-bit or 8-bit mode.
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Required properties:
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- compatible: Must contain "hit,hd44780",
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- data-gpios: Must contain an array of either 4 or 8 GPIO specifiers,
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referring to the GPIO pins connected to the data signal lines DB0-DB7
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(8-bit mode) or DB4-DB7 (4-bit mode) of the LCD Controller's bus interface,
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- enable-gpios: Must contain a GPIO specifier, referring to the GPIO pin
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connected to the "E" (Enable) signal line of the LCD Controller's bus
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interface,
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- rs-gpios: Must contain a GPIO specifier, referring to the GPIO pin
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connected to the "RS" (Register Select) signal line of the LCD Controller's
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bus interface,
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- display-height: Height of the display, in character cells,
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- display-width: Width of the display, in character cells.
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Optional properties:
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- rw-gpios: Must contain a GPIO specifier, referring to the GPIO pin
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connected to the "RW" (Read/Write) signal line of the LCD Controller's bus
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interface,
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- backlight-gpios: Must contain a GPIO specifier, referring to the GPIO pin
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used for enabling the LCD's backlight,
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- internal-buffer-width: Internal buffer width (default is 40 for displays
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with 1 or 2 lines, and display-width for displays with more than 2 lines).
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Example:
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auxdisplay {
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compatible = "hit,hd44780";
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data-gpios = <&hc595 0 GPIO_ACTIVE_HIGH>,
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<&hc595 1 GPIO_ACTIVE_HIGH>,
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<&hc595 2 GPIO_ACTIVE_HIGH>,
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<&hc595 3 GPIO_ACTIVE_HIGH>;
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enable-gpios = <&hc595 4 GPIO_ACTIVE_HIGH>;
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rs-gpios = <&hc595 5 GPIO_ACTIVE_HIGH>;
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display-height = <2>;
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display-width = <16>;
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};