Re: [beagleboard] ADC generic_buffer.c issues || Accessing ADC from own kernel module
Nuno I Tried the file generic_buffer ( found it on the kernel 4.0 :
http://lxr.free-electrons.com/source/drivers/staging/iio/Documentation/generic_buffer.c?v=4.0
)
But I got :
root@beaglebone:/# ./generic_buffer -n TI-am335x-adc -t sysfstrig1 -l 128
iio device number being used is 0
*Failed to find the trigger sysfstrig1*
Maybe I'm not using it correctly
cat /dev/iio\:device0
give a lot of data ^^
Le jeudi 13 août 2015 03:46:58 UTC+2, Nuno a écrit :
>
> On 08/12/2015 06:51 PM, Maro wrote:
> > So the goal is almost identical to the generic_buffer.c application
> > referenced on this wiki [
> > http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide]
> >
>
> It shouldn't matter, but if you are willing to upgrade the kernel (ubuntu
> 14.04, Linux kernel 4.1.4-ti-r9),
> you could follow the updated version instead:
>
> http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User's_Guide
>
> I just used Robert Nelson kernel (linux-image-4.1.4-ti-r9) and
> updated/added the required entry
> to the device tree:
>
> tscadc@44e0d000 {
> compatible = "ti,am3359-tscadc";
> reg = <0x44e0d000 0x1000>;
> interrupt-parent = <0x1>;
> interrupts = <0x10>;
> ti,hwmods = "adc_tsc";
> status = "okay";
> linux,phandle = <0xc5>;
> phandle = <0xc5>;
>
> tsc {
> compatible = "ti,am3359-tsc";
> };
>
> adc {
> #io-channel-cells = <0x1>;
> compatible = "ti,am3359-adc";
> linux,phandle = <0xc6>;
> phandle = <0xc6>;
> ti,adc-channels = <0 1 2 3 4 5 6 7>;
> };
> };
>
>
>
> I didn't try with the .c application with this version yet, but I can read
> the raw values directly:
>
> (AN4 connected to the board analog ground)
>
> ~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
> 12
>
> (AN4 connected to the board 1.8V )
>
> ~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
> 4083
>
>
> cheers,
> Nuno
>
> --
>
--
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Re: [beagleboard] ADC generic_buffer.c issues || Accessing ADC from own kernel module
For the linux-image-4.1.4-ti-r9 RN kernel image- Did you just compile from
source from https://github.com/beagleboard/linux/tree/4.1
-
I can read the values manually too but thats where it starts to fall apart:
root@beaglebone:~# cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw
3885
root@beaglebone:~# cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw
3885
Do you see the buffer dir on the 4.14 kernel- as shown in the ti wiki?
root@arago-armv7:~# ls -al /sys/bus/iio/devices/iio\:device0/buffer/
drwxr-xr-x2 root root0 Jan 1 00:00 .
drwxr-xr-x5 root root0 Jan 1 00:00 ..
-rw-r--r--1 root root 4096 Jan 1 00:01 bytes_per_datum
-rw-r--r--1 root root 4096 Jan 1 00:01 enable
-rw-r--r--1 root root 4096 Jan 1 00:01 length
---
Do you have any problems dropping the adc into continuous mode?
root@arago-armv7:~# echo 1 >
/sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage0_en
root@arago-armv7:~# echo 1 >
/sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage5_en
root@arago-armv7:~# echo 1 >
/sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage7_en
root@arago-armv7:~# echo 100 > /sys/bus/iio/devices/iio\:device0/buffer/length
root@arago-armv7:~# echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable
root@arago-armv7:~# echo 0 > /sys/bus/iio/devices/iio\:device0/buffer/enable
On Wednesday, August 12, 2015 at 7:46:58 PM UTC-6, Nuno wrote:
>
> On 08/12/2015 06:51 PM, Maro wrote:
> > So the goal is almost identical to the generic_buffer.c application
> > referenced on this wiki [
> > http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide]
> >
>
> It shouldn't matter, but if you are willing to upgrade the kernel (ubuntu
> 14.04, Linux kernel 4.1.4-ti-r9),
> you could follow the updated version instead:
>
> http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User's_Guide
>
> I just used Robert Nelson kernel (linux-image-4.1.4-ti-r9) and
> updated/added the required entry
> to the device tree:
>
> tscadc@44e0d000 {
> compatible = "ti,am3359-tscadc";
> reg = <0x44e0d000 0x1000>;
> interrupt-parent = <0x1>;
> interrupts = <0x10>;
> ti,hwmods = "adc_tsc";
> status = "okay";
> linux,phandle = <0xc5>;
> phandle = <0xc5>;
>
> tsc {
> compatible = "ti,am3359-tsc";
> };
>
> adc {
> #io-channel-cells = <0x1>;
> compatible = "ti,am3359-adc";
> linux,phandle = <0xc6>;
> phandle = <0xc6>;
> ti,adc-channels = <0 1 2 3 4 5 6 7>;
> };
> };
>
>
>
> I didn't try with the .c application with this version yet, but I can read
> the raw values directly:
>
> (AN4 connected to the board analog ground)
>
> ~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
> 12
>
> (AN4 connected to the board 1.8V )
>
> ~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
> 4083
>
>
> cheers,
> Nuno
>
> --
>
--
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Re: [beagleboard] ADC generic_buffer.c issues || Accessing ADC from own kernel module
On 08/12/2015 06:51 PM, Maro wrote:
> So the goal is almost identical to the generic_buffer.c application
> referenced on this wiki [
> http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide]
>
It shouldn't matter, but if you are willing to upgrade the kernel (ubuntu
14.04, Linux kernel 4.1.4-ti-r9),
you could follow the updated version instead:
http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User's_Guide
I just used Robert Nelson kernel (linux-image-4.1.4-ti-r9) and updated/added
the required entry
to the device tree:
tscadc@44e0d000 {
compatible = "ti,am3359-tscadc";
reg = <0x44e0d000 0x1000>;
interrupt-parent = <0x1>;
interrupts = <0x10>;
ti,hwmods = "adc_tsc";
status = "okay";
linux,phandle = <0xc5>;
phandle = <0xc5>;
tsc {
compatible = "ti,am3359-tsc";
};
adc {
#io-channel-cells = <0x1>;
compatible = "ti,am3359-adc";
linux,phandle = <0xc6>;
phandle = <0xc6>;
ti,adc-channels = <0 1 2 3 4 5 6 7>;
};
};
I didn't try with the .c application with this version yet, but I can read the
raw values directly:
(AN4 connected to the board analog ground)
~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
12
(AN4 connected to the board 1.8V )
~$ cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
4083
cheers,
Nuno
--
--
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[beagleboard] ADC generic_buffer.c issues || Accessing ADC from own kernel module
Hoping you guys can help me out on this: Goal: High sample rate of one ADC line via a kernel module and a corresponding user space app Now I know the PRU would be great for this- and I plan on also writing a pru version to bench mark the diff but I'm currently trying to get it done with a kernel module and its turned into one of those annoying obsessions that should work and damn it-- I am going to make it work So the goal is almost identical to the generic_buffer.c application referenced on this wiki [ http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide] but I've been fight it for awhile with no results. Current version: Linux beaglebone 3.8.13-bone70 1: pulled there git repo 2: applied the patch to get rid of the trigger stuff found here 3: compiled: gcc --static generic_buffer.c -o generic_buffer 4: Issues happen now because sysfs seem to be so different, I'm not sure contionous mode can be turned on? ./generic_buffer -n tiadc -l 256 -c 1 iio device number being used is 0 Problem reading scan element information diag /sys/bus/iio/devices/iio:device0 5: This error leads down the rabbit hole to this semi unhelpful blog post: https://e2e.ti.com/support/arm/sitara_arm/f/791/t/365886 yielding an errata about `Continuous capture mode is not supported in the 3.12 kernel`; great we are still rocking a 3.8.13 kernel thus should be fine? -- Couple questions: 1: Is there bbb kernel version that plays nice with the iio driver that will allow this generic_buffer.c to work? if so details please 2: if not has anyone modified this demo app to make things work? I've seen a couple posts about it here 2: Is there any information to say screw it and read the adc values directly in my own ko? I've seen instructions on gpio but not the adc lines. -- 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.
