Zach, your suggestions worked. I changed fragment@1 to:
fragment@1 {
target = <&ocp>;
__overlay__ {
test_pru_iomap: pru_iomap {
compatible = "bone-pinmux-helper";
pinctrl-names = "default";
pinctrl-0 = <&mygpio>;
status = "okay";
};
};
recompiled, and then when I loaded the overlay, and later did ADC.setup(),
I was still able to
control the output pins with the ADC simultaneously working using pru0
commands
SET r30.t14
and
CLR r30.t14
I also added pru0 to:
exclusive-use =
"P8.12", "pru0";
as you suggested. Finally, your explanations about which files are being
affected when overlays are loaded
was very illuminating. I have spent time googling to try and understand
what is going on with device trees, and
read articles such as http://www.devicetree.org/Device_Tree_Usage, but your
few lines of explanation have been
more useful than anything I have found to date. If there is an article or
site you would recommend to read, I would
be very interested. Also, if you happen to know where the source code for
Adafruit_BBIO.ADC can be found,
I would be interested in trying to follow it through. Once again, thank you
for your
help; with my limited knowledge re device trees, this is not something I
would have
been able to solve on my own.
Bit Pusher
On Friday, December 6, 2013 2:50:39 PM UTC-5, Zachary Thorson wrote:
>
> Odd, dmesg has no errors, but there is definitely a conflict between the
> two.
>
> Someone can correct me if I am wrong as this is a guess based on the
> behavior of the system (I'll have to look it up later) but loading a device
> tree will dynamically map a bunch of hardware register to the file system
> in certain locations based on the fragment used. Since the dts file you
> posted specified &ocp as the target, it placed it into
> /sys/devices/ocp.*/[Name].
>
> In this case [Name] is the name that you specified is the one inside of
> that __overlay__ keyword. That would be "helper".
>
> I know for sure that the Adafruit Library looks for
> /sys/devices/ocp.*/helper.* to read from and control the ADC registers, so
> if your overlay is overwriting those values, it will lead to problems. I
> am not sure why it would affect your pru code without seeing how you are
> trying to access the IOs.
>
> Anyway, try changing the line:
> test_helper: helper {
>
>
> to something more unique such as:
> pru_iomap {
>
>
> Recompile, then try loading as before.
>
> Though if you are not using the ocp mapping to write to the IO, you could
> probably drop the section. Some of the sample dts files in
> /lib/firmware/BB-BONE-PRU-01.dts do not even map the ocp.
>
> Also, you may want to add "pru0" to your exclusive use list so another
> cape doesn't try to use it at the same time.
>
> After those changes:
>
>
> 0: 54:PF---
> 1: 55:PF---
> 2: 56:PF---
> 3: 57:PF---
> 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
> 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI
> root@beaglebone:~# echo BB-BONE-PRU > $SLOTS
> root@beaglebone:~# cat $SLOTS
> 0: 54:PF---
> 1: 55:PF---
> 2: 56:PF---
> 3: 57:PF---
> 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
> 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI
> 7: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-BONE-PRU
> root@beaglebone:~# python
> Python 2.7.3 (default, May 29 2013, 21:25:00)
> [GCC 4.7.3 20130205 (prerelease)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import Adafruit_BBIO.ADC as ADC
> >>> ADC.setup()
> >>> ADC.read("P9_40")
> 0.86722224950790405
>
>
>
> Let me know how it goes,
> Zachary Thorson
>
>
>
>
>
>
> On Wednesday, December 4, 2013 8:13:14 PM UTC-6, Bit Pusher wrote:
>>
>> Zach, that would be very good of you; I got if from searching on the net
>> and it is barely changed (if at all) from what I found (but I didn't record
>> who I copied it from so I apologize for not giving credit). The *.dts is
>> below. I might mention that if I load my overlay only, then using >cat
>> $PINS, I can see the expected pin change to 6. If I setup the AD first in
>> python, I do not see any changes in the $PINS, and if I then try to load my
>> overlay and check the pins, they are still the same as just after boot.
>> Bit Pusher
>>
>> /lib/firmware\> cat BB-BONE-PRU-00A0.dts
>> /*
>> * pru dts file BB-BONE-PRU-00A0.dts
>> */
>> /dts-v1/;
>> /plugin/;
>>
>> / {
>> compatible = "ti,beaglebone", "ti,beaglebone-black";
>>
>> /* identification */
>> part-number = "BB-BONE-PRU";
>> version = "00A0";
>>
>> exclusive-use =
>> "P8.12";
>>
>> fragment@0 {
>> target = <&am33xx_pinmux>;
>> __overlay__ {
>> mygpio: pinmux_mygpio{
>> pinctrl-single,pins = <
>> 0x30 0x06
>> >;
>> };
>> };
>> };
>>
>> fragment@1 {
>> target = <&ocp>;
>> __overlay__ {
>> test_helper: helper {
>> compatible = "bone-pinmux-helper";
>> pinctrl-names = "default";
>> pinctrl-0 = <&mygpio>;
>> status = "okay";
>> };
>> };
>> };
>>
>> fragment@2{
>> target = <&pruss>;
>> __overlay__ {
>> status = "okay";
>> };
>> };
>> };
>>
>>
>> On Wednesday, December 4, 2013 8:17:47 AM UTC-5, Zachary Thorson wrote:
>>>
>>> Could you post or send me your overlay? I can load it on one of my BBBs
>>> and take a look for you.
>>>
>>> Zach
>>>
>>> On Tuesday, December 3, 2013 8:39:35 PM UTC-6, Bit Pusher wrote:
>>> > If I load my device tree overlay to use the high-speed GPIO pins
>>> first, and then try to read the ADC using Adafruit_BBIO, it kicks me out of
>>> python:
>>> >
>>> >
>>> >
>>> > ~/pru\> sudo python
>>> > Python 2.7.5+ (default, Sep 19 2013, 14:17:30)
>>> > [GCC 4.8.1] on linux2
>>> > Type "help", "copyright", "credits" or "license" for more information.
>>> > >>> import Adafruit_BBIO.ADC as ADC
>>> > >>> ADC.setup()
>>> > >>> ADC.read("P9_40")
>>> > ~/pru\>
>>> >
>>> >
>>> > notice no value returned and no python prompt. I suspect this
>>> indicates a problem.
>>> > I then rebooted (reset switch), waited until the network started
>>> working again (it takes 5 minutes each time for the network to work,
>>> something needs to timeout)
>>> > and then did the same, but this time did not load the device overlay
>>> to change one pru gpio to a high-speed output and got as expected
>>> >
>>> >
>>> >
>>> > ~/pru\> sudo python
>>> > Python 2.7.5+ (default, Sep 19 2013, 14:17:30)
>>> > [GCC 4.8.1] on linux2
>>> > Type "help", "copyright", "credits" or "license" for more information.
>>> > >>> import Adafruit_BBIO.ADC as ADC
>>> > >>> ADC.setup()
>>> > >>> ADC.read("P9_40")
>>> > 0.8072222471237183
>>> > >>>
>>> >
>>> >
>>> > I should mention that when I load both overlays, with my overlay
>>> first, >cat $SLOTS shows them both there, just the ADC overlay load does
>>> not
>>> > work correctly. If I run the ADC.setup() first, and then run
>>> > ~/pru\>>sudo sh -c "echo BB-BONE-PRU > $SLOTS" to load my overlay,
>>> then
>>> >
>>> >
>>> >
>>> >
>>> > /lib/firmware\> cat $SLOTS
>>> > 0: 54:PF---
>>> > 1: 55:PF---
>>> > 2: 56:PF---
>>> > 3: 57:PF---
>>> > 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
>>> > 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI
>>> > 7: ff:P-O-L Override Board Name,00A0,Override Manuf,cape-bone-iio
>>> > 9: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-BONE-PRU
>>> > /lib/firmware\>
>>> >
>>> >
>>> > and both overlays are shown but the high
>>> > speed pin does not work.
>>> > Loading just my overlay only, works as expected as far as I can tell
>>> (i.e. the led turns on and off).
>>> > I'm guessing things are not quite as expected.
>>> > Also, could someone point me to the file in kernel source that loads
>>> overlays?
>>> > Thanks.
>>> > Bit Pusher
>>> >
>>> >
>>> > On Tuesday, December 3, 2013 12:16:34 PM UTC-5, Zachary Thorson wrote:
>>> > Correct me if I am wrong, but it appears that you simply want to use
>>> ADC and PRU pins whose pins DO NOT physically overlap on the board? The
>>> cape-bone-iio device tree only grabs the ADC0-ADC7 pins plus analog power
>>> and ground, so it should not interfere with the PRU pins.
>>> >
>>> >
>>> > What issue are you getting when you try to load the PRU overlay after
>>> loading the ADC overlay?
>>> >
>>> >
>>> >
>>> > Note: The adafruit library has a cleanup function in code, but it is
>>> commented out due to the lockup on load that you are describing.
>>> >
>>> > Zach
>>>
>>>
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