> On Dec 16, 2015, at 7:24 AM, Robert Nelson <[email protected]> wrote:
> 
> On Wed, Dec 16, 2015 at 9:20 AM, William Hermans <[email protected]> wrote:
>>> I use uio_pruss; I am not at all familiar with remoteproc + rpmsg for the
>>> pru (have never even seen any doc on it). I strongly prefer systemd to init.
>>> My largest concern is the device trees overlays (for uio_pruss and pinmux);
>>> if they work, then I think I can get SPIs going. I just got a BBB running on
>>> 8.2 (had a problem with the leds going out rather than all on when flashing
>>> finished). Am able to talk through USB. Can't run scite yet; probably need
>>> to work on x-windows.
>> 
>> 
>> Then, Jessie, or Wheezy will work. Jessie having the newer package repo
>> advantage.
>> 
>> Enabling uio_pruss is really simple:
>> 
>> /dts-v1/;
>> /plugin/;
>> 
>> / {
>>    compatible = "ti,beaglebone", "ti,beaglebone-black";
>> 
>>    /* identification */
>>    part-number = "pruss_enable";
>>    version = "00A0";
>> 
>>     fragment@0 {
>>             target = <&pruss>;
>>           __overlay__ {
>>                      status = "okay";
>> 
>>                   };
>>        };
>> 
>> };
>> 
>> debian@beaglebone:~$ dtc -O dtb -o pru_enable-00A0.dtbo -b 0 -@
>> pru_enable-00A0.dts
>> debian@beaglebone:~$ sudo cp pru_enable-00A0.dtbo /lib/firmware/
>> debian@beaglebone:~$ sudo sh -c "echo 'pru_enable' >
>> /sys/devices/platform/bone_capemgr/slots"
>> debian@beaglebone:~$ dmesg | grep pru
>> [ 3699.525797] bone_capemgr bone_capemgr: part_number 'pru_enable', version
>> 'N/A'
>> [ 3699.545863] bone_capemgr bone_capemgr: slot #4: 'Override Board
>> Name,00A0,Override Manuf,pru_enable'
>> [ 3699.557512] bone_capemgr bone_capemgr: slot #4: dtbo
>> 'pru_enable-00A0.dtbo' loaded; overlay id #0
>> [ 3699.579751] pruss_uio 4a300000.pruss: pins are not configured from the
>> driver
>> 
>> debian@beaglebone:~$ lsmod |grep pru
>> uio_pruss               4143  0
>> uio                     8006  2 uio_pruss,uio_pdrv_genirq
>> 
>> I'd also recommend upgrading to a 4.1.x kernel as well( if you haven't
>> already ). It works great with uio_pruss, but no personal hands on with SPI
>> just yet. I've been considering testing, and blogging on my findings.
>> Problem is, I'm not exactly an EE, and connecting SPI between embedded
>> platforms is not exactly a direct connect situation( LIke UART ). Which is
>> exactly how I'd test. Using an MSP430 Launchpad, or an LM4F120 launchpad as
>> a slave device.
> 
> SPI works great on v4.1.x now, just pay attention this this little
> spi-dma-disable hack:
> 
> https://github.com/beagleboard/bb.org-overlays/blob/master/src/arm/BB-SPIDEV0-00A0.dts#L54
> 
> "ti,pio-mode;"
> 
> Otherwise, the spidev interface will lock up on the 160'th bit...
> 
> (3.8 never used dma on spi, so this isn't a regression in speed..)
I believe the problem is in spidev which probably doesn't allocate DMA-coherent 
memory for the buffer. If you use McSPI and allocate DMA-coherent memory for 
the buffer it works just fine for > 160 bytes. 

Regards,
John
> 
> Regards,
> 
> -- 
> Robert Nelson
> https://rcn-ee.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 [email protected].
> 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 [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to