From: Siddarth Sharma <[email protected]> Reply-To: "[email protected]" <[email protected]> Date: Tuesday, August 19, 2014 at 9:02 AM To: "[email protected]" <[email protected]> Subject: [beagleboard] Re: SPI with DMA
> I'm using BeagleBone with AM3517 and Linux kernel version: 2.6.37 BeagleBone use AM3359 or AM3358 processors. When using the mcspi driver, DMA is automatically invoked when the size of your transfer exceeds a defined threshold which you will find in the mcspi driver. If you want to see how this is done, look at examples of SPI drivers in the /drivers/iio or /drivers/staging/iio folder. BTW, you don¹t invoke the mcspi driver functions directly. Instead you use the generic linux SPI functions which in turn call the mcspi functions. Read the /Documentation/spi docs. Regards, John > > > On Tuesday, August 19, 2014 5:00:24 PM UTC+1, Siddarth Sharma wrote: >> Hi Folks, >> >> I have recently decided to learn embedded linux development and I am >> currently working on a project to use the SPI on Beagle Bone to transfer >> 64+bytes of data as one block in one write cycle to an Atmel SAM 32 bit uC. I >> would like to use DMA with the SPI and I have read online that this is not >> possible from user space with spidev. I came across omap2_mcspi.c driver and >> I noticed that this has dma functions in it. I would like to enable two DMA >> channels(tx and rx) to provide and receive data from the respective registers >> on the SPI. Could someone guide as to how I am to go about using omap2_mcspi? >> Would i need to make a module? >> >> Thanks! > -- > 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.
