--- zzzz-none-000/linux-4.4.271/Documentation/devicetree/bindings/gpio/gpio.txt 2021-06-03 06:22:09.000000000 +0000 +++ hawkeye-5590-750/linux-4.4.271/Documentation/devicetree/bindings/gpio/gpio.txt 2023-04-19 10:22:27.000000000 +0000 @@ -145,6 +145,21 @@ and which are dummies. The bindings for this case has not yet been specified, but should be specified if/when such hardware appears. +Optionally, a GPIO controller may have a "gpio-line-names" property. This is +an array of strings defining the names of the GPIO lines going out of the +GPIO controller. This name should be the most meaningful producer name +for the system, such as a rail name indicating the usage. Package names +such as pin name are discouraged: such lines have opaque names (since they +are by definition generic purpose) and such names are usually not very +helpful. For example "MMC-CD", "Red LED Vdd" and "ethernet reset" are +reasonable line names as they describe what the line is used for. "GPIO0" +is not a good name to give to a GPIO line. Placeholders are discouraged: +rather use the "" (blank string) if the use of the GPIO line is undefined +in your design. The names are assigned starting from line offset 0 from +left to right from the passed array. An incomplete array (where the number +of passed named are less than ngpios) will still be used up until the last +provided valid line index. + Example: gpio-controller@00000000 { @@ -153,6 +168,10 @@ gpio-controller; #gpio-cells = <2>; ngpios = <18>; + gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R", + "LED G", "LED B", "Col A", "Col B", "Col C", "Col D", + "Row A", "Row B", "Row C", "Row D", "NMI button", + "poweroff", "reset"; } The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism