> On Dec 16, 2015, at 10:13 AM, John Syne <[email protected]> wrote:
> 
> 
> 
>> On Dec 16, 2015, at 7:41 AM, Robert Nelson <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> 
>> 
>> On Wed, Dec 16, 2015 at 9:31 AM, William Hermans <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 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
>>  
>> <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..)
>> 
>> Is it possible to control the SPI hardware through the PRU, and if so, would 
>> that hack still matter Robert ? No idea if spidev is used in such a case or 
>> not . . . 
> Yes, you can control the SPI with the PRU. Take the SPI driver from 
> Starterware and adapt it to work on the PRU and then build with the PRU C 
> compiler. SPIDEV is a Linux feature and has nothing to do with the PRU. 
> Starterware is barebone programming where you manipulate the peripheral, bus 
> and clock registers directly using the CortexA8 ARM processor. The PRU can 
> manipulate these same registers. From what I remember, there is a github 
> project that has already ported some of the Starterware drivers to work on 
> the PRU.
Search github for starterware_PRU

Regards,
John
> 
> Regards,
> John
>> 
>> I didn't investage that side..  It's just when used as an overlay, that's 
>> needed..
>> 
>> If you setup a *.dtb with spi enabled in the dtb-rebuilder you don't need 
>> that workaround..
>> 
>> https://github.com/RobertCNelson/dtb-rebuilder/blob/4.1-ti/src/arm/am335x-boneblack-spi0.dts#L140
>>  
>> <https://github.com/RobertCNelson/dtb-rebuilder/blob/4.1-ti/src/arm/am335x-boneblack-spi0.dts#L140>
>> 
>> Regards,
>> 
>> -- 
>> Robert Nelson
>> https://rcn-ee.com/ <https://rcn-ee.com/>
>> 
>> -- 
>> For more options, visit http://beagleboard.org/discuss 
>> <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] 
>> <mailto:[email protected]>.
>> For more options, visit https://groups.google.com/d/optout 
>> <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