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Diffstat (limited to 'Documentation/devicetree/bindings/leds/common.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/leds/common.txt | 77 |
1 files changed, 64 insertions, 13 deletions
diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt index 68419843e32f..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 @@ -19,6 +19,13 @@ Optional properties for child nodes: a device, i.e. no other LED class device can be assigned the same label. +- default-state : The initial state of the LED. Valid values are "on", "off", + and "keep". If the LED is already on or off and the default-state property is + set the to same value, then no glitch should be produced where the LED + momentarily turns off (or on). The "keep" setting will keep the LED at + whatever its current state is, without producing a glitch. The default is + off if this property is not present. + - linux,default-trigger : This parameter, if present, is a string defining the trigger assigned to the LED. Current triggers are: "backlight" - LED will act as a back-light, controlled by the framebuffer @@ -26,7 +33,9 @@ Optional properties for child nodes: "default-on" - LED will turn on (but for leds-gpio see "default-state" property in Documentation/devicetree/bindings/gpio/led.txt) "heartbeat" - LED "double" flashes at a load average based rate - "ide-disk" - LED indicates disk activity + "disk-activity" - LED indicates disk activity + "ide-disk" - LED indicates IDE disk activity (deprecated), + in new implementations use "disk-activity" "timer" - LED flashes at a fixed, configurable rate - led-max-microamp : Maximum LED supply current in microamperes. This property @@ -37,6 +46,25 @@ Optional properties for child nodes: property is mandatory for the LEDs in the non-flash modes (e.g. torch or indicator). +- 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 @@ -47,18 +75,41 @@ 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). -system-status { - label = "Status"; - linux,default-trigger = "heartbeat"; - ... +* Examples + +gpio-leds { + compatible = "gpio-leds"; + + system-status { + label = "Status"; + linux,default-trigger = "heartbeat"; + gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>; + }; + + usb { + gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>; + trigger-sources = <&ohci_port1>, <&ehci_port1>; + }; }; -camera-flash { - label = "Flash"; - led-sources = <0>, <1>; - led-max-microamp = <50000>; - flash-max-microamp = <320000>; - flash-max-timeout-us = <500000>; +max77693-led { + compatible = "maxim,max77693-led"; + + camera-flash { + label = "Flash"; + led-sources = <0>, <1>; + led-max-microamp = <50000>; + flash-max-microamp = <320000>; + flash-max-timeout-us = <500000>; + }; }; |