* Hardware blink and brightness @ 2016-05-19 15:57 Tony Makkiel 2016-05-20 7:25 ` Jacek Anaszewski 0 siblings, 1 reply; 3+ messages in thread From: Tony Makkiel @ 2016-05-19 15:57 UTC (permalink / raw) To: linux-leds Hi, Is there any particular reason to stipulate, (hardware) blink should be turned off, when brightness is set to 0? Following is copied from "Documentation/leds/leds-class.txt" "Setting the brightness to zero with brightness_set() callback function should completely turn off the LED and cancel the previously programmed hardware blinking function, if any." The chip driver could also use other methods for the same, keeping brightness independent of blink. For example, delay_on/off delay_off=0 ==> blink off, led on. delay_on=0 ==> blink off, led off. Or am I overlooking something? Many Thanks, Tony ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Hardware blink and brightness 2016-05-19 15:57 Hardware blink and brightness Tony Makkiel @ 2016-05-20 7:25 ` Jacek Anaszewski 2016-05-26 14:48 ` Tony Makkiel 0 siblings, 1 reply; 3+ messages in thread From: Jacek Anaszewski @ 2016-05-20 7:25 UTC (permalink / raw) To: Tony Makkiel; +Cc: linux-leds Hi Tony, On 05/19/2016 05:57 PM, Tony Makkiel wrote: > Hi, > Is there any particular reason to stipulate, (hardware) blink should be turned off, when brightness is set to 0? Following is copied from "Documentation/leds/leds-class.txt" > > "Setting the brightness to zero with brightness_set() callback function > should completely turn off the LED and cancel the previously programmed > hardware blinking function, if any." > > The chip driver could also use other methods for the same, keeping brightness independent of blink. > > For example, delay_on/off > delay_off=0 ==> blink off, led on. > delay_on=0 ==> blink off, led off. > > Or am I overlooking something? Setting brightness to zero not only disables blinking but also any other active trigger. Besides, would it make sense to have blinking enabled with brightness set to 0? Anyway, we have to keep this interface as-is so as not to break existing users of the LED API. -- Best regards, Jacek Anaszewski ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Hardware blink and brightness 2016-05-20 7:25 ` Jacek Anaszewski @ 2016-05-26 14:48 ` Tony Makkiel 0 siblings, 0 replies; 3+ messages in thread From: Tony Makkiel @ 2016-05-26 14:48 UTC (permalink / raw) To: linux-leds; +Cc: Tony Makkiel On 20/05/16 08:25, Jacek Anaszewski wrote: > Hi Tony, > > On 05/19/2016 05:57 PM, Tony Makkiel wrote: >> Hi, >> Is there any particular reason to stipulate, (hardware) blink should be turned off, when brightness is set to 0? Following is copied from "Documentation/leds/leds-class.txt" >> >> "Setting the brightness to zero with brightness_set() callback function >> should completely turn off the LED and cancel the previously programmed >> hardware blinking function, if any." >> >> The chip driver could also use other methods for the same, keeping brightness independent of blink. >> >> For example, delay_on/off >> delay_off=0 ==> blink off, led on. >> delay_on=0 ==> blink off, led off. >> >> Or am I overlooking something? > > Setting brightness to zero not only disables blinking but also > any other active trigger. Besides, would it make sense to have > blinking enabled with brightness set to 0? I agree brightness set to 0, should turn off led. I was thinking of case when user turns led back ON with a brightness value. Ideally led comes back on blinking as was configured previously(making, brightness and blink independent). At present, once the brightness is set, blink also needs to be reconfigured. > > Anyway, we have to keep this interface as-is so as not to break > existing users of the LED API. I see your point now, Thank you. I was under the wrong impression, this could be achieved without code change. Initially, I thought of using delay_on/delay_off, to turn off blink. But with this approach, even if it will save a step initially (no need to reconfigure blink), will add additional step (re-enable trigger) to disable blink. > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-05-26 14:48 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-05-19 15:57 Hardware blink and brightness Tony Makkiel 2016-05-20 7:25 ` Jacek Anaszewski 2016-05-26 14:48 ` Tony Makkiel
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.