diff options
Diffstat (limited to 'Documentation/devicetree/bindings/gpio')
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index c88d2cc..68d28f6 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -152,6 +152,21 @@ additional bitmask is needed to specify which GPIOs are actually in use, 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 { @@ -160,6 +175,10 @@ gpio-controller@00000000 { 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 |
