Re: [beagleboard] /sys/class/gpio vs. DTB

2016-04-03 Thread Rick Mann 
Yeah, as I was saying, I actually do remember how to do that, and successfully 
did. I still end up having to do the export and then other sysfs stuff to set 
the values.

Which, as I think about it, setting the values in the DTB is not so useful.* I 
do need to turn things on and off only under software control. But it'd be nice 
to get rid of the export step.

*There are a couple of GPIOs that turn regulators on and enable some of my 
audio circuitry. In theory, I can build the device tree including those, and 
then the audio APIs turn them on automatically when audio is enabled. But I've 
had limited success with getting that right.

> On Apr 3, 2016, at 17:26 , William Hermans  wrote:
> 
> Here Rick, maybe this will refresh you on the subject. 
> http://stackoverflow.com/questions/16872763/configuring-pins-mode-beaglebone 
> second answer I think talks about device tree files, while the first one 
> talks about some crazy script method . . .
> 
> But essentially, and I'm no expert here, and from the second answer . . .
> 
> pinctrl-single,pins = <
> 0x070 0x2f /* P9_11 30 INPUT MODE7 none */
> 0x074 0x2f /* P9_13 31 INPUT MODE7 none */
> 0x040 0x2f /* P9_15 48 INPUT MODE7 none */
> 0x15c 0x2f /* P9_17 05 INPUT MODE7 none */
> >;
> 
> This in it's self does a lot of explaining here. Check out the comments for 
> each pin, and mode. 
> 
> On Sun, Apr 3, 2016 at 5:18 PM, Rick Mann  wrote:
> 
> > On Apr 3, 2016, at 17:07 , William Hermans  wrote:
> >
> > Yes, it can be done. I thought you had all this down before ? You can 
> > configure what mode the pin is actually used for - The several different 
> > peripheral types per pin, or GPIO + pull up/down or neither, and pin 
> > direction.
> 
> Sorry, I haven't been able to touch this since last summer, and I don't 
> always remember what I figured out. I do recall that I can set up the pin, 
> but I've never figured out for sure how to set the output state.
> 
> Also, I've never succeeded in getting a full DTB working (one that sets up my 
> pins, ADC, PRU, and audio). I'm hoping enough progress has been made in the 
> kernels that I can finally get there. And I'm getting closer, just not quite 
> there yet.
> 
> --
> Rick Mann
> rm...@latencyzero.com
> 
> 
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google Groups 
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
> 
> 
> -- 
> For more options, visit http://beagleboard.org/discuss
> --- 
> You received this message because you are subscribed to the Google Groups 
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.


-- 
Rick Mann
rm...@latencyzero.com


-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [beagleboard] /sys/class/gpio vs. DTB

2016-04-03 Thread William Hermans 
Here Rick, maybe this will refresh you on the subject.
http://stackoverflow.com/questions/16872763/configuring-pins-mode-beaglebone
second answer I think talks about device tree files, while the first one
talks about some crazy script method . . .

But essentially, and I'm no expert here, and from the second answer . . .

pinctrl-single,pins = <
0x070 0x2f /* P9_11 30 INPUT MODE7 none */
0x074 0x2f /* P9_13 31 INPUT MODE7 none */
0x040 0x2f /* P9_15 48 INPUT MODE7 none */
0x15c 0x2f /* P9_17 05 INPUT MODE7 none */
>;

This in it's self does a lot of explaining here. Check out the comments for
each pin, and mode.

On Sun, Apr 3, 2016 at 5:18 PM, Rick Mann  wrote:

>
> > On Apr 3, 2016, at 17:07 , William Hermans  wrote:
> >
> > Yes, it can be done. I thought you had all this down before ? You can
> configure what mode the pin is actually used for - The several different
> peripheral types per pin, or GPIO + pull up/down or neither, and pin
> direction.
>
> Sorry, I haven't been able to touch this since last summer, and I don't
> always remember what I figured out. I do recall that I can set up the pin,
> but I've never figured out for sure how to set the output state.
>
> Also, I've never succeeded in getting a full DTB working (one that sets up
> my pins, ADC, PRU, and audio). I'm hoping enough progress has been made in
> the kernels that I can finally get there. And I'm getting closer, just not
> quite there yet.
>
> --
> Rick Mann
> rm...@latencyzero.com
>
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google Groups
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [beagleboard] /sys/class/gpio vs. DTB

2016-04-03 Thread Rick Mann 

> On Apr 3, 2016, at 17:07 , William Hermans  wrote:
> 
> Yes, it can be done. I thought you had all this down before ? You can 
> configure what mode the pin is actually used for - The several different 
> peripheral types per pin, or GPIO + pull up/down or neither, and pin 
> direction.

Sorry, I haven't been able to touch this since last summer, and I don't always 
remember what I figured out. I do recall that I can set up the pin, but I've 
never figured out for sure how to set the output state.

Also, I've never succeeded in getting a full DTB working (one that sets up my 
pins, ADC, PRU, and audio). I'm hoping enough progress has been made in the 
kernels that I can finally get there. And I'm getting closer, just not quite 
there yet.

-- 
Rick Mann
rm...@latencyzero.com


-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [beagleboard] /sys/class/gpio vs. DTB

2016-04-03 Thread William Hermans 
>
> *configure a few GPIOs for my application. Is this something that can be
> accomplished entirely via DTB?*
>
> * # cd /sys/class/gpio*
>
> * # echo 50 > export*
> * # echo 115 > export*
> * # echo out > gpio50/direction*
> * # echo out > gpio115/direction*
>
> * # echo 1 > gpio50/value*
> * # echo 1 > gpio115/value*
>
> * # echo 0 > gpio50/value*
> * # echo 0 > gpio115/value*
>
> * That is, setting which GPIOs are enabled, setting their direction, and
> setting their output state?*
>
> * Thanks,*
>

Yes, it can be done. I thought you had all this down before ? You can
configure what mode the pin is actually used for - The several different
peripheral types per pin, or GPIO + pull up/down or neither, and pin
direction.

On Sun, Apr 3, 2016 at 4:52 PM, John Syne  wrote:

> Why not do it in your applications?
>
> http://derekmolloy.ie/kernel-gpio-programming-buttons-and-leds/
>
> Regards,
> John
>
>
>
>
> > On Apr 3, 2016, at 4:14 PM, Rick Mann  wrote:
> >
> > I configure a few GPIOs for my application. Is this something that can
> be accomplished entirely via DTB?
> >
> >   # cd /sys/class/gpio
> >
> >   # echo 50 > export
> >   # echo 115 > export
> >   # echo out > gpio50/direction
> >   # echo out > gpio115/direction
> >
> >   # echo 1 > gpio50/value
> >   # echo 1 > gpio115/value
> >
> >   # echo 0 > gpio50/value
> >   # echo 0 > gpio115/value
> >
> > That is, setting which GPIOs are enabled, setting their direction, and
> setting their output state?
> >
> > Thanks,
> >
> > --
> > Rick Mann
> > rm...@latencyzero.com
> >
> >
> > --
> > For more options, visit http://beagleboard.org/discuss
> > ---
> > You received this message because you are subscribed to the Google
> Groups "BeagleBoard" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to beagleboard+unsubscr...@googlegroups.com.
> > For more options, visit https://groups.google.com/d/optout.
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google Groups
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [beagleboard] /sys/class/gpio vs. DTB

2016-04-03 Thread John Syne 
Why not do it in your applications?

http://derekmolloy.ie/kernel-gpio-programming-buttons-and-leds/

Regards,
John




> On Apr 3, 2016, at 4:14 PM, Rick Mann  wrote:
> 
> I configure a few GPIOs for my application. Is this something that can be 
> accomplished entirely via DTB?
> 
>   # cd /sys/class/gpio
>   
>   # echo 50 > export
>   # echo 115 > export
>   # echo out > gpio50/direction
>   # echo out > gpio115/direction
> 
>   # echo 1 > gpio50/value
>   # echo 1 > gpio115/value
>   
>   # echo 0 > gpio50/value
>   # echo 0 > gpio115/value
> 
> That is, setting which GPIOs are enabled, setting their direction, and 
> setting their output state?
> 
> Thanks,
> 
> -- 
> Rick Mann
> rm...@latencyzero.com
> 
> 
> -- 
> For more options, visit http://beagleboard.org/discuss
> --- 
> You received this message because you are subscribed to the Google Groups 
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.