1.. SPDX-License-Identifier: GPL-2.0+
2
3
4LG Gram laptop extra features
5=============================
6
7By Matan Ziv-Av <matan@svgalib.org>
8
9
10Hotkeys
11-------
12
13The following FN keys are ignored by the kernel without this driver:
14
15- FN-F1 (LG control panel)   - Generates F15
16- FN-F5 (Touchpad toggle)    - Generates F21
17- FN-F6 (Airplane mode)      - Generates RFKILL
18- FN-F9 (Reader mode)        - Generates F14
19
20The rest of the FN keys work without a need for a special driver.
21
22
23Reader mode
24-----------
25
26Writing 0/1 to /sys/devices/platform/lg-laptop/reader_mode disables/enables
27reader mode. In this mode the screen colors change (blue color reduced),
28and the reader mode indicator LED (on F9 key) turns on.
29
30
31FN Lock
32-------
33
34Writing 0/1 to /sys/devices/platform/lg-laptop/fn_lock disables/enables
35FN lock.
36
37
38Battery care limit
39------------------
40
41Writing 80/100 to /sys/class/power_supply/CMB0/charge_control_end_threshold
42sets the maximum capacity to charge the battery. Limiting the charge
43reduces battery capacity loss over time.
44
45This value is reset to 100 when the kernel boots.
46
47
48Fan mode
49--------
50
51Writing 1/0 to /sys/devices/platform/lg-laptop/fan_mode disables/enables
52the fan silent mode.
53
54
55USB charge
56----------
57
58Writing 0/1 to /sys/devices/platform/lg-laptop/usb_charge disables/enables
59charging another device from the USB port while the device is turned off.
60
61This value is reset to 0 when the kernel boots.
62
63
64LEDs
65~~~~
66
67The are two LED devices supported by the driver:
68
69Keyboard backlight
70------------------
71
72A led device named kbd_led controls the keyboard backlight. There are three
73lighting level: off (0), low (127) and high (255).
74
75The keyboard backlight is also controlled by the key combination FN-F8
76which cycles through those levels.
77
78
79Touchpad indicator LED
80----------------------
81
82On the F5 key. Controlled by led device names tpad_led.
83