diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/leds/common.txt | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt index 24b656014089..1d4afe9644b6 100644 --- a/Documentation/devicetree/bindings/leds/common.txt +++ b/Documentation/devicetree/bindings/leds/common.txt @@ -1,4 +1,4 @@ -Common leds properties. +* Common leds properties. LED and flash LED devices provide the same basic functionality as current regulators, but extended with LED and flash LED specific features like @@ -49,6 +49,22 @@ Optional properties for child nodes: - panic-indicator : This property specifies that the LED should be used, if at all possible, as a panic indicator. +- trigger-sources : List of devices which should be used as a source triggering + this LED activity. Some LEDs can be related to a specific + device and should somehow indicate its state. E.g. USB 2.0 + LED may react to device(s) in a USB 2.0 port(s). + Another common example is switch or router with multiple + Ethernet ports each of them having its own LED assigned + (assuming they are not hardwired). In such cases this + property should contain phandle(s) of related source + device(s). + In many cases LED can be related to more than one device + (e.g. one USB LED vs. multiple USB ports). Each source + should be represented by a node in the device tree and be + referenced by a phandle and a set of phandle arguments. A + length of arguments should be specified by the + #trigger-source-cells property in the source node. + Required properties for flash LED child nodes: - flash-max-microamp : Maximum flash LED supply current in microamperes. - flash-max-timeout-us : Maximum timeout in microseconds after which the flash @@ -59,7 +75,17 @@ property can be omitted. For controllers that have no configurable timeout the flash-max-timeout-us property can be omitted. -Examples: +* Trigger source providers + +Each trigger source should be represented by a device tree node. It may be e.g. +a USB port or an Ethernet device. + +Required properties for trigger source: +- #trigger-source-cells : Number of cells in a source trigger. Typically 0 for + nodes of simple trigger sources (e.g. a specific USB + port). + +* Examples gpio-leds { compatible = "gpio-leds"; @@ -69,6 +95,11 @@ gpio-leds { linux,default-trigger = "heartbeat"; gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>; }; + + usb { + gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>; + trigger-sources = <&ohci_port1>, <&ehci_port1>; + }; }; max77693-led { |