Hi Terrence. Yes i am writing a kernel module and interfacing with it from user space.
As i went through the same period like you do now i'll be glad to help you. The first step is to allocate the buffers that the edma will use source and destination buffers as well . as edma needs special buffers. The second step is to allocate the channels you want. Then comes the configuration of the transfer of each channel. As you can understand i cant describe the hole process in detail as edma and its applications are quite complicated. if you can be more specific ill be glad to give you more specific information. On Fri, Dec 13, 2013 at 3:31 AM, Terrence McGuckin <[email protected]> wrote: > I am working on EDMA ATM as well. I was curious if you could write a > little bit about how you are initializing the channels and setting up the > transfers. Are you writing a kernel module for this and interfacing to it > in user-space? > > Appreciate any insight, having a hard time digging up info on using EDMA > on the Beaglebone > > On Thursday, November 7, 2013 10:06:53 AM UTC-5, [email protected]: >> >> Greeting again everyone!. >> >> I am using beaglebone with angstrom. >> >> I am trying( by writing a kernel module ) to loop two dma channels >> together but i cant figure out how.... >> >> Here is what i want. i want the completion of the 1st channel to trigger >> the final interrupt(callback1) and also channel 2. >> and at the completion of channel 2 to trigger the final interrupt >> (callback2) and also channel 1. etc... creating a loop between ch1 and ch2. >> >> By linking the channels it seems that i cant link channel 2 back to >> channel 1. ( >> >> edma_link(ch1, ch2); >> edma_link(ch2, ch1); system fail. >> >> i can only link ch2 on its self >> >> edma_link(ch1, ch2); >> edma_link(ch2, ch2); >> >> but i dont want that. >> >> By chaining the final interrupt is not going off. so i dont want that >> either. >> >> I tried to link edma_link(ch1, ch2) then chain ch2 with a ch3 and >> have edma_link(ch3, ch1); >> >> but then ch1 callback1 returns DMA_CC_ERROR with its paramset being NULL >> (so the error is from that). >> >> Any suggestions ? >> > -- 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/groups/opt_out.
