On Mon, Mar 20, 2017 at 10:27 AM, Geert Uytterhoeven <[email protected]> wrote: > Hi Rob, Greg, > > On Mon, Mar 20, 2017 at 4:15 PM, Rob Herring <[email protected]> wrote: >> On Fri, Mar 10, 2017 at 03:15:20PM +0100, Geert Uytterhoeven wrote: >>> 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]> > >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt > >>> +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. >> >> display-{width,height}-chars > > Makes sense. > > Greg: As this is already in char-misc-next, shall I send an update for > the bindings > and the driver? > >>> +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, >> >> Active state? > > That's typically handled via the last cell of the GPIO specifier, cfr. > GPIO_ACTIVE_HIGH / GPIO_ACTIVE_LOW in <dt-bindings/gpio/gpio.h>.
Yes, I know. I want to be able to read the binding and validate the dts file, so I need to know what is the correct flag. Rob
