Re: [PATCH] OMAP3: RX51: support sleep indicator LEDs

[Roger Quadros <ext-roger.quadros@nokia.com>]

ext Kevin Hilman wrote:
> Jonathan McDowell <noodles@earth.li> writes:
> 
>> On Fri, Oct 02, 2009 at 08:35:55AM -0700, Kevin Hilman wrote:
>>> The sleep indicator LEDs can be enabled/disabled by toggling GPIO162.
>>> Request this GPIO in RX51 board init, disable by default and expose
>>> GPIO162 to userspace so LEDs can be toggled from userspace:
>> Wouldn't this be better done using the LED class subsystem?
> 
> No, these are HW controlled LEDs which blink based on whether the OMAP
> is hitting retention or OFF mode etc.  The software has no control
> over the blinking of LEDs themselves.  The GPIO simply enables them.
> 
> Kevin
> 

Actually, i think it would make sense to use LED class subsystem, even if the 
GPIO does not directly control LEDs because

1) it does indirectly control a group of LEDs. enable/disable

2) it solves our GPIO numbering problem. user-space does not need to care about 
or track which GPIO to set/reset

3) Makes better sense from architecture point of view

	User-space will write to /sys/class/leds/debug_leds/brightness

-roger

> 
>>> To enable:
>>>
>>>   # echo 1 > /sys/class/gpio/gpio162/value
>>>
>>> To disable:
>>>
>>>   # echo 0 > /sys/class/gpio/gpio162/value
>>>
>>> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
>>> ---
>> J.
>>
>> -- 
>> 101 things you can't have too much of : 16 - Time.
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