diff options
author | Len Brown <len.brown@intel.com> | 2009-09-19 01:55:27 -0400 |
---|---|---|
committer | Len Brown <len.brown@intel.com> | 2009-09-19 01:55:27 -0400 |
commit | b4549a24b6194201077d0295207ec204f785fab1 (patch) | |
tree | d290a7868f12a1b62aba0449f6c693dd0ff91130 /Documentation | |
parent | 3bb29ec14ce5f448ab37a5da16c3d720ae5af9cf (diff) | |
parent | 52cc96bd5b61775db2792780c610979fc02313eb (diff) |
Merge branch 'asus' into release
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/stable/sysfs-class-backlight | 36 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-class-lcd | 23 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-class-led | 28 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-platform-asus-laptop | 52 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-platform-eeepc-laptop | 50 | ||||
-rw-r--r-- | Documentation/laptops/asus-laptop.txt | 258 | ||||
-rw-r--r-- | Documentation/leds-class.txt | 9 |
7 files changed, 452 insertions, 4 deletions
diff --git a/Documentation/ABI/stable/sysfs-class-backlight b/Documentation/ABI/stable/sysfs-class-backlight new file mode 100644 index 000000000000..4d637e1c4ff7 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-class-backlight | |||
@@ -0,0 +1,36 @@ | |||
1 | What: /sys/class/backlight/<backlight>/bl_power | ||
2 | Date: April 2005 | ||
3 | KernelVersion: 2.6.12 | ||
4 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
5 | Description: | ||
6 | Control BACKLIGHT power, values are FB_BLANK_* from fb.h | ||
7 | - FB_BLANK_UNBLANK (0) : power on. | ||
8 | - FB_BLANK_POWERDOWN (4) : power off | ||
9 | Users: HAL | ||
10 | |||
11 | What: /sys/class/backlight/<backlight>/brightness | ||
12 | Date: April 2005 | ||
13 | KernelVersion: 2.6.12 | ||
14 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
15 | Description: | ||
16 | Control the brightness for this <backlight>. Values | ||
17 | are between 0 and max_brightness. This file will also | ||
18 | show the brightness level stored in the driver, which | ||
19 | may not be the actual brightness (see actual_brightness). | ||
20 | Users: HAL | ||
21 | |||
22 | What: /sys/class/backlight/<backlight>/actual_brightness | ||
23 | Date: March 2006 | ||
24 | KernelVersion: 2.6.17 | ||
25 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
26 | Description: | ||
27 | Show the actual brightness by querying the hardware. | ||
28 | Users: HAL | ||
29 | |||
30 | What: /sys/class/backlight/<backlight>/max_brightness | ||
31 | Date: April 2005 | ||
32 | KernelVersion: 2.6.12 | ||
33 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
34 | Description: | ||
35 | Maximum brightness for <backlight>. | ||
36 | Users: HAL | ||
diff --git a/Documentation/ABI/testing/sysfs-class-lcd b/Documentation/ABI/testing/sysfs-class-lcd new file mode 100644 index 000000000000..35906bf7aa70 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-lcd | |||
@@ -0,0 +1,23 @@ | |||
1 | What: /sys/class/lcd/<lcd>/lcd_power | ||
2 | Date: April 2005 | ||
3 | KernelVersion: 2.6.12 | ||
4 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
5 | Description: | ||
6 | Control LCD power, values are FB_BLANK_* from fb.h | ||
7 | - FB_BLANK_UNBLANK (0) : power on. | ||
8 | - FB_BLANK_POWERDOWN (4) : power off | ||
9 | |||
10 | What: /sys/class/lcd/<lcd>/contrast | ||
11 | Date: April 2005 | ||
12 | KernelVersion: 2.6.12 | ||
13 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
14 | Description: | ||
15 | Current contrast of this LCD device. Value is between 0 and | ||
16 | /sys/class/lcd/<lcd>/max_contrast. | ||
17 | |||
18 | What: /sys/class/lcd/<lcd>/max_contrast | ||
19 | Date: April 2005 | ||
20 | KernelVersion: 2.6.12 | ||
21 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
22 | Description: | ||
23 | Maximum contrast for this LCD device. | ||
diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led new file mode 100644 index 000000000000..9e4541d71cb6 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led | |||
@@ -0,0 +1,28 @@ | |||
1 | What: /sys/class/leds/<led>/brightness | ||
2 | Date: March 2006 | ||
3 | KernelVersion: 2.6.17 | ||
4 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
5 | Description: | ||
6 | Set the brightness of the LED. Most LEDs don't | ||
7 | have hardware brightness support so will just be turned on for | ||
8 | non-zero brightness settings. The value is between 0 and | ||
9 | /sys/class/leds/<led>/max_brightness. | ||
10 | |||
11 | What: /sys/class/leds/<led>/max_brightness | ||
12 | Date: March 2006 | ||
13 | KernelVersion: 2.6.17 | ||
14 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
15 | Description: | ||
16 | Maximum brightness level for this led, default is 255 (LED_FULL). | ||
17 | |||
18 | What: /sys/class/leds/<led>/trigger | ||
19 | Date: March 2006 | ||
20 | KernelVersion: 2.6.17 | ||
21 | Contact: Richard Purdie <rpurdie@rpsys.net> | ||
22 | Description: | ||
23 | Set the trigger for this LED. A trigger is a kernel based source | ||
24 | of led events. | ||
25 | You can change triggers in a similar manner to the way an IO | ||
26 | scheduler is chosen. Trigger specific parameters can appear in | ||
27 | /sys/class/leds/<led> once a given trigger is selected. | ||
28 | |||
diff --git a/Documentation/ABI/testing/sysfs-platform-asus-laptop b/Documentation/ABI/testing/sysfs-platform-asus-laptop new file mode 100644 index 000000000000..a1cb660c50cf --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-asus-laptop | |||
@@ -0,0 +1,52 @@ | |||
1 | What: /sys/devices/platform/asus-laptop/display | ||
2 | Date: January 2007 | ||
3 | KernelVersion: 2.6.20 | ||
4 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
5 | Description: | ||
6 | This file allows display switching. The value | ||
7 | is composed by 4 bits and defined as follow: | ||
8 | 4321 | ||
9 | |||`- LCD | ||
10 | ||`-- CRT | ||
11 | |`--- TV | ||
12 | `---- DVI | ||
13 | Ex: - 0 (0000b) means no display | ||
14 | - 3 (0011b) CRT+LCD. | ||
15 | |||
16 | What: /sys/devices/platform/asus-laptop/gps | ||
17 | Date: January 2007 | ||
18 | KernelVersion: 2.6.20 | ||
19 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
20 | Description: | ||
21 | Control the gps device. 1 means on, 0 means off. | ||
22 | Users: Lapsus | ||
23 | |||
24 | What: /sys/devices/platform/asus-laptop/ledd | ||
25 | Date: January 2007 | ||
26 | KernelVersion: 2.6.20 | ||
27 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
28 | Description: | ||
29 | Some models like the W1N have a LED display that can be | ||
30 | used to display several informations. | ||
31 | To control the LED display, use the following : | ||
32 | echo 0x0T000DDD > /sys/devices/platform/asus-laptop/ | ||
33 | where T control the 3 letters display, and DDD the 3 digits display. | ||
34 | The DDD table can be found in Documentation/laptops/asus-laptop.txt | ||
35 | |||
36 | What: /sys/devices/platform/asus-laptop/bluetooth | ||
37 | Date: January 2007 | ||
38 | KernelVersion: 2.6.20 | ||
39 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
40 | Description: | ||
41 | Control the bluetooth device. 1 means on, 0 means off. | ||
42 | This may control the led, the device or both. | ||
43 | Users: Lapsus | ||
44 | |||
45 | What: /sys/devices/platform/asus-laptop/wlan | ||
46 | Date: January 2007 | ||
47 | KernelVersion: 2.6.20 | ||
48 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
49 | Description: | ||
50 | Control the bluetooth device. 1 means on, 0 means off. | ||
51 | This may control the led, the device or both. | ||
52 | Users: Lapsus | ||
diff --git a/Documentation/ABI/testing/sysfs-platform-eeepc-laptop b/Documentation/ABI/testing/sysfs-platform-eeepc-laptop new file mode 100644 index 000000000000..7445dfb321b5 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-eeepc-laptop | |||
@@ -0,0 +1,50 @@ | |||
1 | What: /sys/devices/platform/eeepc-laptop/disp | ||
2 | Date: May 2008 | ||
3 | KernelVersion: 2.6.26 | ||
4 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
5 | Description: | ||
6 | This file allows display switching. | ||
7 | - 1 = LCD | ||
8 | - 2 = CRT | ||
9 | - 3 = LCD+CRT | ||
10 | If you run X11, you should use xrandr instead. | ||
11 | |||
12 | What: /sys/devices/platform/eeepc-laptop/camera | ||
13 | Date: May 2008 | ||
14 | KernelVersion: 2.6.26 | ||
15 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
16 | Description: | ||
17 | Control the camera. 1 means on, 0 means off. | ||
18 | |||
19 | What: /sys/devices/platform/eeepc-laptop/cardr | ||
20 | Date: May 2008 | ||
21 | KernelVersion: 2.6.26 | ||
22 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
23 | Description: | ||
24 | Control the card reader. 1 means on, 0 means off. | ||
25 | |||
26 | What: /sys/devices/platform/eeepc-laptop/cpufv | ||
27 | Date: Jun 2009 | ||
28 | KernelVersion: 2.6.31 | ||
29 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
30 | Description: | ||
31 | Change CPU clock configuration. | ||
32 | On the Eee PC 1000H there are three available clock configuration: | ||
33 | * 0 -> Super Performance Mode | ||
34 | * 1 -> High Performance Mode | ||
35 | * 2 -> Power Saving Mode | ||
36 | On Eee PC 701 there is only 2 available clock configurations. | ||
37 | Available configuration are listed in available_cpufv file. | ||
38 | Reading this file will show the raw hexadecimal value which | ||
39 | is defined as follow: | ||
40 | | 8 bit | 8 bit | | ||
41 | | `---- Current mode | ||
42 | `------------ Availables modes | ||
43 | For example, 0x301 means: mode 1 selected, 3 available modes. | ||
44 | |||
45 | What: /sys/devices/platform/eeepc-laptop/available_cpufv | ||
46 | Date: Jun 2009 | ||
47 | KernelVersion: 2.6.31 | ||
48 | Contact: "Corentin Chary" <corentincj@iksaif.net> | ||
49 | Description: | ||
50 | List available cpufv modes. | ||
diff --git a/Documentation/laptops/asus-laptop.txt b/Documentation/laptops/asus-laptop.txt new file mode 100644 index 000000000000..c1c5be84e4b1 --- /dev/null +++ b/Documentation/laptops/asus-laptop.txt | |||
@@ -0,0 +1,258 @@ | |||
1 | Asus Laptop Extras | ||
2 | |||
3 | Version 0.1 | ||
4 | August 6, 2009 | ||
5 | |||
6 | Corentin Chary <corentincj@iksaif.net> | ||
7 | http://acpi4asus.sf.net/ | ||
8 | |||
9 | This driver provides support for extra features of ACPI-compatible ASUS laptops. | ||
10 | It may also support some MEDION, JVC or VICTOR laptops (such as MEDION 9675 or | ||
11 | VICTOR XP7210 for example). It makes all the extra buttons generate standard | ||
12 | ACPI events that go through /proc/acpi/events and input events (like keyboards). | ||
13 | On some models adds support for changing the display brightness and output, | ||
14 | switching the LCD backlight on and off, and most importantly, allows you to | ||
15 | blink those fancy LEDs intended for reporting mail and wireless status. | ||
16 | |||
17 | This driver supercedes the old asus_acpi driver. | ||
18 | |||
19 | Requirements | ||
20 | ------------ | ||
21 | |||
22 | Kernel 2.6.X sources, configured for your computer, with ACPI support. | ||
23 | You also need CONFIG_INPUT and CONFIG_ACPI. | ||
24 | |||
25 | Status | ||
26 | ------ | ||
27 | |||
28 | The features currently supported are the following (see below for | ||
29 | detailed description): | ||
30 | |||
31 | - Fn key combinations | ||
32 | - Bluetooth enable and disable | ||
33 | - Wlan enable and disable | ||
34 | - GPS enable and disable | ||
35 | - Video output switching | ||
36 | - Ambient Light Sensor on and off | ||
37 | - LED control | ||
38 | - LED Display control | ||
39 | - LCD brightness control | ||
40 | - LCD on and off | ||
41 | |||
42 | A compatibility table by model and feature is maintained on the web | ||
43 | site, http://acpi4asus.sf.net/. | ||
44 | |||
45 | Usage | ||
46 | ----- | ||
47 | |||
48 | Try "modprobe asus_acpi". Check your dmesg (simply type dmesg). You should | ||
49 | see some lines like this : | ||
50 | |||
51 | Asus Laptop Extras version 0.42 | ||
52 | L2D model detected. | ||
53 | |||
54 | If it is not the output you have on your laptop, send it (and the laptop's | ||
55 | DSDT) to me. | ||
56 | |||
57 | That's all, now, all the events generated by the hotkeys of your laptop | ||
58 | should be reported in your /proc/acpi/event entry. You can check with | ||
59 | "acpi_listen". | ||
60 | |||
61 | Hotkeys are also reported as input keys (like keyboards) you can check | ||
62 | which key are supported using "xev" under X11. | ||
63 | |||
64 | You can get informations on the version of your DSDT table by reading the | ||
65 | /sys/devices/platform/asus-laptop/infos entry. If you have a question or a | ||
66 | bug report to do, please include the output of this entry. | ||
67 | |||
68 | LEDs | ||
69 | ---- | ||
70 | |||
71 | You can modify LEDs be echoing values to /sys/class/leds/asus::*/brightness : | ||
72 | echo 1 > /sys/class/leds/asus::mail/brightness | ||
73 | will switch the mail LED on. | ||
74 | You can also know if they are on/off by reading their content and use | ||
75 | kernel triggers like ide-disk or heartbeat. | ||
76 | |||
77 | Backlight | ||
78 | --------- | ||
79 | |||
80 | You can control lcd backlight power and brightness with | ||
81 | /sys/class/backlight/asus-laptop/. Brightness Values are between 0 and 15. | ||
82 | |||
83 | Wireless devices | ||
84 | --------------- | ||
85 | |||
86 | You can turn the internal Bluetooth adapter on/off with the bluetooth entry | ||
87 | (only on models with Bluetooth). This usually controls the associated LED. | ||
88 | Same for Wlan adapter. | ||
89 | |||
90 | Display switching | ||
91 | ----------------- | ||
92 | |||
93 | Note: the display switching code is currently considered EXPERIMENTAL. | ||
94 | |||
95 | Switching works for the following models: | ||
96 | L3800C | ||
97 | A2500H | ||
98 | L5800C | ||
99 | M5200N | ||
100 | W1000N (albeit with some glitches) | ||
101 | M6700R | ||
102 | A6JC | ||
103 | F3J | ||
104 | |||
105 | Switching doesn't work for the following: | ||
106 | M3700N | ||
107 | L2X00D (locks the laptop under certain conditions) | ||
108 | |||
109 | To switch the displays, echo values from 0 to 15 to | ||
110 | /sys/devices/platform/asus-laptop/display. The significance of those values | ||
111 | is as follows: | ||
112 | |||
113 | +-------+-----+-----+-----+-----+-----+ | ||
114 | | Bin | Val | DVI | TV | CRT | LCD | | ||
115 | +-------+-----+-----+-----+-----+-----+ | ||
116 | + 0000 + 0 + + + + + | ||
117 | +-------+-----+-----+-----+-----+-----+ | ||
118 | + 0001 + 1 + + + + X + | ||
119 | +-------+-----+-----+-----+-----+-----+ | ||
120 | + 0010 + 2 + + + X + + | ||
121 | +-------+-----+-----+-----+-----+-----+ | ||
122 | + 0011 + 3 + + + X + X + | ||
123 | +-------+-----+-----+-----+-----+-----+ | ||
124 | + 0100 + 4 + + X + + + | ||
125 | +-------+-----+-----+-----+-----+-----+ | ||
126 | + 0101 + 5 + + X + + X + | ||
127 | +-------+-----+-----+-----+-----+-----+ | ||
128 | + 0110 + 6 + + X + X + + | ||
129 | +-------+-----+-----+-----+-----+-----+ | ||
130 | + 0111 + 7 + + X + X + X + | ||
131 | +-------+-----+-----+-----+-----+-----+ | ||
132 | + 1000 + 8 + X + + + + | ||
133 | +-------+-----+-----+-----+-----+-----+ | ||
134 | + 1001 + 9 + X + + + X + | ||
135 | +-------+-----+-----+-----+-----+-----+ | ||
136 | + 1010 + 10 + X + + X + + | ||
137 | +-------+-----+-----+-----+-----+-----+ | ||
138 | + 1011 + 11 + X + + X + X + | ||
139 | +-------+-----+-----+-----+-----+-----+ | ||
140 | + 1100 + 12 + X + X + + + | ||
141 | +-------+-----+-----+-----+-----+-----+ | ||
142 | + 1101 + 13 + X + X + + X + | ||
143 | +-------+-----+-----+-----+-----+-----+ | ||
144 | + 1110 + 14 + X + X + X + + | ||
145 | +-------+-----+-----+-----+-----+-----+ | ||
146 | + 1111 + 15 + X + X + X + X + | ||
147 | +-------+-----+-----+-----+-----+-----+ | ||
148 | |||
149 | In most cases, the appropriate displays must be plugged in for the above | ||
150 | combinations to work. TV-Out may need to be initialized at boot time. | ||
151 | |||
152 | Debugging: | ||
153 | 1) Check whether the Fn+F8 key: | ||
154 | a) does not lock the laptop (try disabling CONFIG_X86_UP_APIC or boot with | ||
155 | noapic / nolapic if it does) | ||
156 | b) generates events (0x6n, where n is the value corresponding to the | ||
157 | configuration above) | ||
158 | c) actually works | ||
159 | Record the disp value at every configuration. | ||
160 | 2) Echo values from 0 to 15 to /sys/devices/platform/asus-laptop/display. | ||
161 | Record its value, note any change. If nothing changes, try a broader range, | ||
162 | up to 65535. | ||
163 | 3) Send ANY output (both positive and negative reports are needed, unless your | ||
164 | machine is already listed above) to the acpi4asus-user mailing list. | ||
165 | |||
166 | Note: on some machines (e.g. L3C), after the module has been loaded, only 0x6n | ||
167 | events are generated and no actual switching occurs. In such a case, a line | ||
168 | like: | ||
169 | |||
170 | echo $((10#$arg-60)) > /sys/devices/platform/asus-laptop/display | ||
171 | |||
172 | will usually do the trick ($arg is the 0000006n-like event passed to acpid). | ||
173 | |||
174 | Note: there is currently no reliable way to read display status on xxN | ||
175 | (Centrino) models. | ||
176 | |||
177 | LED display | ||
178 | ----------- | ||
179 | |||
180 | Some models like the W1N have a LED display that can be used to display | ||
181 | several informations. | ||
182 | |||
183 | LED display works for the following models: | ||
184 | W1000N | ||
185 | W1J | ||
186 | |||
187 | To control the LED display, use the following : | ||
188 | |||
189 | echo 0x0T000DDD > /sys/devices/platform/asus-laptop/ | ||
190 | |||
191 | where T control the 3 letters display, and DDD the 3 digits display, | ||
192 | according to the tables below. | ||
193 | |||
194 | DDD (digits) | ||
195 | 000 to 999 = display digits | ||
196 | AAA = --- | ||
197 | BBB to FFF = turn-off | ||
198 | |||
199 | T (type) | ||
200 | 0 = off | ||
201 | 1 = dvd | ||
202 | 2 = vcd | ||
203 | 3 = mp3 | ||
204 | 4 = cd | ||
205 | 5 = tv | ||
206 | 6 = cpu | ||
207 | 7 = vol | ||
208 | |||
209 | For example "echo 0x01000001 >/sys/devices/platform/asus-laptop/ledd" | ||
210 | would display "DVD001". | ||
211 | |||
212 | Driver options: | ||
213 | --------------- | ||
214 | |||
215 | Options can be passed to the asus-laptop driver using the standard | ||
216 | module argument syntax (<param>=<value> when passing the option to the | ||
217 | module or asus-laptop.<param>=<value> on the kernel boot line when | ||
218 | asus-laptop is statically linked into the kernel). | ||
219 | |||
220 | wapf: WAPF defines the behavior of the Fn+Fx wlan key | ||
221 | The significance of values is yet to be found, but | ||
222 | most of the time: | ||
223 | - 0x0 should do nothing | ||
224 | - 0x1 should allow to control the device with Fn+Fx key. | ||
225 | - 0x4 should send an ACPI event (0x88) while pressing the Fn+Fx key | ||
226 | - 0x5 like 0x1 or 0x4 | ||
227 | |||
228 | The default value is 0x1. | ||
229 | |||
230 | Unsupported models | ||
231 | ------------------ | ||
232 | |||
233 | These models will never be supported by this module, as they use a completely | ||
234 | different mechanism to handle LEDs and extra stuff (meaning we have no clue | ||
235 | how it works): | ||
236 | |||
237 | - ASUS A1300 (A1B), A1370D | ||
238 | - ASUS L7300G | ||
239 | - ASUS L8400 | ||
240 | |||
241 | Patches, Errors, Questions: | ||
242 | -------------------------- | ||
243 | |||
244 | I appreciate any success or failure | ||
245 | reports, especially if they add to or correct the compatibility table. | ||
246 | Please include the following information in your report: | ||
247 | |||
248 | - Asus model name | ||
249 | - a copy of your ACPI tables, using the "acpidump" utility | ||
250 | - a copy of /sys/devices/platform/asus-laptop/infos | ||
251 | - which driver features work and which don't | ||
252 | - the observed behavior of non-working features | ||
253 | |||
254 | Any other comments or patches are also more than welcome. | ||
255 | |||
256 | acpi4asus-user@lists.sourceforge.net | ||
257 | http://sourceforge.net/projects/acpi4asus | ||
258 | |||
diff --git a/Documentation/leds-class.txt b/Documentation/leds-class.txt index 6399557cdab3..8fd5ca2ae32d 100644 --- a/Documentation/leds-class.txt +++ b/Documentation/leds-class.txt | |||
@@ -1,3 +1,4 @@ | |||
1 | |||
1 | LED handling under Linux | 2 | LED handling under Linux |
2 | ======================== | 3 | ======================== |
3 | 4 | ||
@@ -5,10 +6,10 @@ If you're reading this and thinking about keyboard leds, these are | |||
5 | handled by the input subsystem and the led class is *not* needed. | 6 | handled by the input subsystem and the led class is *not* needed. |
6 | 7 | ||
7 | In its simplest form, the LED class just allows control of LEDs from | 8 | In its simplest form, the LED class just allows control of LEDs from |
8 | userspace. LEDs appear in /sys/class/leds/. The brightness file will | 9 | userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the |
9 | set the brightness of the LED (taking a value 0-255). Most LEDs don't | 10 | LED is defined in max_brightness file. The brightness file will set the brightness |
10 | have hardware brightness support so will just be turned on for non-zero | 11 | of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware |
11 | brightness settings. | 12 | brightness support so will just be turned on for non-zero brightness settings. |
12 | 13 | ||
13 | The class also introduces the optional concept of an LED trigger. A trigger | 14 | The class also introduces the optional concept of an LED trigger. A trigger |
14 | is a kernel based source of led events. Triggers can either be simple or | 15 | is a kernel based source of led events. Triggers can either be simple or |