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From 01/29/2016 to 02/27/2016

02/01/2016

JC 10:49 AM Software Development: RE: Spidev issues
Fred, I'm not sure what is wrong. Perhaps if you sent us your schematic someone could look it over.
I'm pretty sure the spidev driver works. However you could try implementing a simple kernel driver to access the spi calls directly....
Jonathan Cormier

01/29/2016

FF 03:08 PM Software Development: RE: Spidev issues
A single IOCTL call with len=4 returns 4 bytes of 0 value instead of 2 with no difference in the SPI signals. Fred Frantz
JC 12:04 PM Software Development: RE: Spidev issues
I believe you want a single IOCTL. See the attached source code duplex method.
Example usage
Jonathan Cormier
FF 11:51 AM Software Development: RE: Spidev issues
Correction in above code
fd = open(devname, O_RDWR|O_SYNC);
should be
fd = open(devname, O_RDWR);
Fred Frantz
FF 11:49 AM Software Development: RE: Spidev issues
This is based on spidev_test.c and other examples. There are two devices on the bus that have to be configured to read address input pins before they can be configured. That is working fine since the correct device is responding to the ... Fred Frantz
JC 11:06 AM Software Development: RE: Spidev issues
Fred Frantz wrote:
> Yes, I am looking at all the SPI0 signals on a scope, and they are correct. The transmitted data is configuring the devices correctly, and the received data from the device on d1 is correct, but it is not returned ...
Jonathan Cormier
FF 11:02 AM Software Development: RE: Spidev issues
Yes, I am looking at all the SPI0 signals on a scope, and they are correct. The transmitted data is configuring the devices correctly, and the received data from the device on d1 is correct, but it is not returned from ioctl(). I have v... Fred Frantz
JC 10:44 AM Software Development: RE: Spidev issues
Fred Frantz wrote:
> The data is now being clocked out correctly, and the device is responding with the correct data on the spi0_d1 line.
Does this mean you have a spi analyser attached to the bus?
Jonathan Cormier
JC 10:42 AM Software Development: RE: Spidev issues
Fred Frantz wrote:
> Mike, are you referring to the .d0_is_mosi parameter in the ompa2_mcspi_device_config structure?
Yes. You should have it correct if you are seeing the data output coming on the correct pin.
> ...
Not that I can th...
Jonathan Cormier
FF 10:36 AM Software Development: RE: Spidev issues
Mike, are you referring to the .d0_is_mosi parameter in the ompa2_mcspi_device_config structure? That is set to 1, but all of the SPI_MODE's give a similar result. All the data bytes returned are the same value, which is not what is be... Fred Frantz
 

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