1-*- org -*- 2 3It is somehow important to provide consistent interface to the 4userland. LED devices have one problem there, and that is naming of 5directories in /sys/class/leds. It would be nice if userland would 6just know right "name" for given LED function, but situation got more 7complex. 8 9Anyway, if backwards compatibility is not an issue, new code should 10use one of the "good" names from this list, and you should extend the 11list where applicable. 12 13Legacy names are listed, too; in case you are writing application that 14wants to use particular feature, you should probe for good name, first, 15but then try the legacy ones, too. 16 17Notice there's a list of functions in include/dt-bindings/leds/common.h . 18 19* Gamepads and joysticks 20 21Game controllers may feature LEDs to indicate a player number. This is commonly 22used on game consoles in which multiple controllers can be connected to a system. 23The "player LEDs" are then programmed with a pattern to indicate a particular 24player. For example, a game controller with 4 LEDs, may be programmed with "x---" 25to indicate player 1, "-x--" to indicate player 2 etcetera where "x" means on. 26Input drivers can utilize the LED class to expose the individual player LEDs 27of a game controller using the function "player". 28Note: tracking and management of Player IDs is the responsibility of user space, 29though drivers may pick a default value. 30 31Good: "input*:*:player-{1,2,3,4,5} 32 33* Keyboards 34 35Good: "input*:*:capslock" 36Good: "input*:*:scrolllock" 37Good: "input*:*:numlock" 38Legacy: "shift-key-light" (Motorola Droid 4, capslock) 39 40Set of common keyboard LEDs, going back to PC AT or so. 41 42Legacy: "tpacpi::thinklight" (IBM/Lenovo Thinkpads) 43Legacy: "lp5523:kb{1,2,3,4,5,6}" (Nokia N900) 44 45Frontlight/backlight of main keyboard. 46 47Legacy: "button-backlight" (Motorola Droid 4) 48 49Some phones have touch buttons below screen; it is different from main 50keyboard. And this is their backlight. 51 52* Sound subsystem 53 54Good: "platform:*:mute" 55Good: "platform:*:micmute" 56 57LEDs on notebook body, indicating that sound input / output is muted. 58 59* System notification 60 61Good: "rgb:status" 62Legacy: "status-led:{red,green,blue}" (Motorola Droid 4) 63Legacy: "lp5523:{r,g,b}" (Nokia N900) 64 65Phones usually have multi-color status LED. 66 67* Power management 68 69Good: "platform:*:charging" (allwinner sun50i, leds-cht-wcove) 70 71* Screen 72 73Good: ":backlight" (Motorola Droid 4) 74 75* Ethernet LEDs 76 77Currently two types of Network LEDs are support, those controlled by 78the PHY and those by the MAC. In theory both can be present at the 79same time for one Linux netdev, hence the names need to differ between 80MAC and PHY. 81 82Do not use the netdev name, such as eth0, enp1s0. These are not stable 83and are not unique. They also don't differentiate between MAC and PHY. 84 85** MAC LEDs 86 87Good: f1070000.ethernet:white:WAN 88Good: mdio_mux-0.1:00:green:left 89Good: 0000:02:00.0:yellow:top 90 91The first part must uniquely name the MAC controller. Then follows the 92colour. WAN/LAN should be used for a single LED. If there are 93multiple LEDs, use left/right, or top/bottom to indicate their 94position on the RJ45 socket. 95 96** PHY LEDs 97 98Good: f1072004.mdio-mii:00: white:WAN 99Good: !mdio-mux!mdio@2!switch@0!mdio:01:green:right 100Good: r8169-0-200:00:yellow:bottom 101 102The first part must uniquely name the PHY. This often means uniquely 103identifying the MDIO bus controller, and the address on the bus. 104