lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 16 Mar 2012 11:24:47 -0400 From: simon@...gewell.org To: linux-input@...r.kernel.org Cc: linux-kernel@...r.kernel.org Subject: Building BarGraph with LED subsystem Hi all, I have a couple of questions about the (user-land) use of the LED subsystem. I recently offered a patch for controlling the LEDs of the G27 gaming wheel, on which the LEDs are arranged in a bar-graph of 5 to show simulation RPM. The suggestion was to use the LED subsystem, which this patch implements. http://www.spinics.net/lists/linux-input/msg19747.html Thinking further about how to about how to control this I was wondering whether a 'threshold' trigger would be useful. This would allow the use of value (uint?) to be compare against a threshold and the LED turned on/off automatically. The main benefit of doing this as a 'trigger' is that we could 'link' (or 'sync') multiple LEDs to use the same value input, thus making the user-land stuff trivial. Concept - ledtrig-thres would provide the controls: threshold - value to compare against. value - incoming value, if >= threshold LED is lit, if < threshold LED is dark. link - 'none' (standalone comparison), or the path to the value of another LED's value to use (ie '/sys/leds/my_device::2/value') Comments? Is this all too complex? Also I have a question about the default permissions on the LED controls; Is it possible to register LEDs so that users have write permission? At present the controls are only accessible as root. Many thanks, Simon. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists