1 -*- org -*- 1 -*- org -*-
2 2
3 It is somehow important to provide consistent 3 It is somehow important to provide consistent interface to the
4 userland. LED devices have one problem there, 4 userland. LED devices have one problem there, and that is naming of
5 directories in /sys/class/leds. It would be ni 5 directories in /sys/class/leds. It would be nice if userland would
6 just know right "name" for given LED function, 6 just know right "name" for given LED function, but situation got more
7 complex. 7 complex.
8 8
9 Anyway, if backwards compatibility is not an i 9 Anyway, if backwards compatibility is not an issue, new code should
10 use one of the "good" names from this list, an 10 use one of the "good" names from this list, and you should extend the
11 list where applicable. 11 list where applicable.
12 12
13 Legacy names are listed, too; in case you are 13 Legacy names are listed, too; in case you are writing application that
14 wants to use particular feature, you should pr 14 wants to use particular feature, you should probe for good name, first,
15 but then try the legacy ones, too. 15 but then try the legacy ones, too.
16 16
17 Notice there's a list of functions in include/ 17 Notice there's a list of functions in include/dt-bindings/leds/common.h .
18 18
19 * Gamepads and joysticks 19 * Gamepads and joysticks
20 20
21 Game controllers may feature LEDs to indicate 21 Game controllers may feature LEDs to indicate a player number. This is commonly
22 used on game consoles in which multiple contro 22 used on game consoles in which multiple controllers can be connected to a system.
23 The "player LEDs" are then programmed with a p 23 The "player LEDs" are then programmed with a pattern to indicate a particular
24 player. For example, a game controller with 4 24 player. For example, a game controller with 4 LEDs, may be programmed with "x---"
25 to indicate player 1, "-x--" to indicate playe 25 to indicate player 1, "-x--" to indicate player 2 etcetera where "x" means on.
26 Input drivers can utilize the LED class to exp 26 Input drivers can utilize the LED class to expose the individual player LEDs
27 of a game controller using the function "playe 27 of a game controller using the function "player".
28 Note: tracking and management of Player IDs is 28 Note: tracking and management of Player IDs is the responsibility of user space,
29 though drivers may pick a default value. 29 though drivers may pick a default value.
30 30
31 Good: "input*:*:player-{1,2,3,4,5} 31 Good: "input*:*:player-{1,2,3,4,5}
32 32
33 * Keyboards 33 * Keyboards
34 34
35 Good: "input*:*:capslock" 35 Good: "input*:*:capslock"
36 Good: "input*:*:scrolllock" 36 Good: "input*:*:scrolllock"
37 Good: "input*:*:numlock" 37 Good: "input*:*:numlock"
38 Legacy: "shift-key-light" (Motorola Droid 4, c 38 Legacy: "shift-key-light" (Motorola Droid 4, capslock)
39 39
40 Set of common keyboard LEDs, going back to PC 40 Set of common keyboard LEDs, going back to PC AT or so.
41 41
42 Legacy: "tpacpi::thinklight" (IBM/Lenovo Think 42 Legacy: "tpacpi::thinklight" (IBM/Lenovo Thinkpads)
43 Legacy: "lp5523:kb{1,2,3,4,5,6}" (Nokia N900) 43 Legacy: "lp5523:kb{1,2,3,4,5,6}" (Nokia N900)
44 44
45 Frontlight/backlight of main keyboard. 45 Frontlight/backlight of main keyboard.
46 46
47 Legacy: "button-backlight" (Motorola Droid 4) 47 Legacy: "button-backlight" (Motorola Droid 4)
48 48
49 Some phones have touch buttons below screen; i 49 Some phones have touch buttons below screen; it is different from main
50 keyboard. And this is their backlight. 50 keyboard. And this is their backlight.
51 51
52 * Sound subsystem 52 * Sound subsystem
53 53
54 Good: "platform:*:mute" 54 Good: "platform:*:mute"
55 Good: "platform:*:micmute" 55 Good: "platform:*:micmute"
56 56
57 LEDs on notebook body, indicating that sound i 57 LEDs on notebook body, indicating that sound input / output is muted.
58 58
59 * System notification 59 * System notification
60 60
61 Good: "rgb:status" 61 Good: "rgb:status"
62 Legacy: "status-led:{red,green,blue}" (Motorol 62 Legacy: "status-led:{red,green,blue}" (Motorola Droid 4)
63 Legacy: "lp5523:{r,g,b}" (Nokia N900) 63 Legacy: "lp5523:{r,g,b}" (Nokia N900)
64 64
65 Phones usually have multi-color status LED. 65 Phones usually have multi-color status LED.
66 66
67 * Power management 67 * Power management
68 68
69 Good: "platform:*:charging" (allwinner sun50i, 69 Good: "platform:*:charging" (allwinner sun50i, leds-cht-wcove)
70 70
71 * Screen 71 * Screen
72 72
73 Good: ":backlight" (Motorola Droid 4) 73 Good: ":backlight" (Motorola Droid 4)
74 74
75 * Indicators <<
76 <<
77 Good: ":indicator" (Blinkm) <<
78 <<
79 * RGB <<
80 <<
81 Good: ":rgb" (Blinkm) <<
82 <<
83 * Ethernet LEDs 75 * Ethernet LEDs
84 76
85 Currently two types of Network LEDs are suppor 77 Currently two types of Network LEDs are support, those controlled by
86 the PHY and those by the MAC. In theory both c 78 the PHY and those by the MAC. In theory both can be present at the
87 same time for one Linux netdev, hence the name 79 same time for one Linux netdev, hence the names need to differ between
88 MAC and PHY. 80 MAC and PHY.
89 81
90 Do not use the netdev name, such as eth0, enp1 82 Do not use the netdev name, such as eth0, enp1s0. These are not stable
91 and are not unique. They also don't differenti 83 and are not unique. They also don't differentiate between MAC and PHY.
92 84
93 ** MAC LEDs 85 ** MAC LEDs
94 86
95 Good: f1070000.ethernet:white:WAN 87 Good: f1070000.ethernet:white:WAN
96 Good: mdio_mux-0.1:00:green:left 88 Good: mdio_mux-0.1:00:green:left
97 Good: 0000:02:00.0:yellow:top 89 Good: 0000:02:00.0:yellow:top
98 90
99 The first part must uniquely name the MAC cont 91 The first part must uniquely name the MAC controller. Then follows the
100 colour. WAN/LAN should be used for a single L 92 colour. WAN/LAN should be used for a single LED. If there are
101 multiple LEDs, use left/right, or top/bottom t 93 multiple LEDs, use left/right, or top/bottom to indicate their
102 position on the RJ45 socket. 94 position on the RJ45 socket.
103 95
104 ** PHY LEDs 96 ** PHY LEDs
105 97
106 Good: f1072004.mdio-mii:00: white:WAN 98 Good: f1072004.mdio-mii:00: white:WAN
107 Good: !mdio-mux!mdio@2!switch@0!mdio:01:green: 99 Good: !mdio-mux!mdio@2!switch@0!mdio:01:green:right
108 Good: r8169-0-200:00:yellow:bottom 100 Good: r8169-0-200:00:yellow:bottom
109 101
110 The first part must uniquely name the PHY. Thi 102 The first part must uniquely name the PHY. This often means uniquely
111 identifying the MDIO bus controller, and the a 103 identifying the MDIO bus controller, and the address on the bus.
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