Lines Matching +full:charge +full:- +full:led
2 LED handling under Linux
5 In its simplest form, the LED class just allows control of LEDs from
7 LED is defined in max_brightness file. The brightness file will set the brightness
8 of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware
9 brightness support so will just be turned on for non-zero brightness settings.
11 The class also introduces the optional concept of an LED trigger. A trigger
12 is a kernel based source of led events. Triggers can either be simple or
14 existing subsystems with minimal additional code. Examples are the disk-activity,
15 nand-disk and sharpsl-charge triggers. With led triggers disabled, the code
18 Complex triggers while available to all LEDs have LED specific
19 parameters and work on a per LED basis. The timer trigger is an example.
20 The timer trigger will periodically change the LED brightness between
23 You can change the brightness value of a LED independently of the timer
41 LED Device Naming
48 - devicename:
57 - color:
59 include/dt-bindings/leds/common.h.
61 - function:
63 include/dt-bindings/leds/common.h.
66 to linux-leds@vger.kernel.org.
68 It is possible that more than one LED with the same color and function will
71 name with required "-N" suffix in the driver. fwnode based drivers can use
72 function-enumerator property for that and then the concatenation will be handled
73 automatically by the LED core upon LED class device registration.
75 LED subsystem has also a protection against name clash, that may occur
76 when LED class device is created by a driver of hot-pluggable device and
78 suffix (e.g. "_1", "_2", "_3" etc.) is added to the requested LED class
81 There might be still LED class drivers around using vendor or product name
86 Examples of proper LED names:
88 - "red:disk"
89 - "white:flash"
90 - "red:indicator"
91 - "phy1:green:wlan"
92 - "phy3::wlan"
93 - ":kbd_backlight"
94 - "input5::kbd_backlight"
95 - "input3::numlock"
96 - "input3::scrolllock"
97 - "input3::capslock"
98 - "mmc1::status"
99 - "white:status"
101 get_led_device_info.sh script can be used for verifying if the LED name
102 meets the requirements pointed out here. It performs validation of the LED class
107 - input devices
108 - ieee80211 compliant USB devices
112 There have been calls for LED properties such as color to be exported as
113 individual led class attributes. As a solution which doesn't incur as much
122 LED subsystem core exposes following API for setting brightness:
124 - led_set_brightness:
128 - led_set_brightness_sync:
129 for use cases when immediate effect is desired -
132 blinking, returns -EBUSY if software blink fallback is enabled.
135 LED registration API
138 A driver wanting to register a LED classdev for use by other drivers /
142 free-ing the led_classdev struct.
154 support this feature, a LED driver can optionally implement the
155 blink_set() function (see <linux/leds.h>). To set an LED to blinking,
169 should completely turn off the LED and cancel the previously programmed
176 The LED Trigger core cannot be a module as the simple trigger functions
179 rest of the LED subsystem can be modular.
185 At the moment, a trigger can't be created specifically for a single LED.
187 particular LED (ACPI?). The addition of triggers provided by the LED driver