Messages in this thread | | | Date | Sat, 26 Jan 2008 19:46:02 -0600 | From | Robert Hancock <> | Subject | Re: Custom PCIe Device Driver |
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Sanka Piyaratna wrote: > Hi Everyone, > > I am currently developing a custom PCIe device and the Linux kernel > driver for this. I am able to use the device as a character device with > PIO and now I am working on getting the DMA to work. I have implemented > 2 BARs (BAR0 - mem and BAR5 - mem) in the PCIe device. I have > implemented the DMA in my custom device firmware to transfer a block of > memory via the PCIe bus and now trying to get this to work with the > device driver. > > As I understand it, I can get hold of the PCI bus to become the bus > master and then initiate the DMA transfer from my device. However, I > don't understand how I can specify within my kernel driver how to > specify which BAR to use. > > Does this mean when I initiate a transfer from the hardware, the memory > get transferred into the location allocated by by pci_map_single() > function regardless of which BAR the memory comes from? or do I need to > specify the BAR using a mask? > > Would some one be able to point me to an example code please? > > Thanks and Regards, > > Sanka
Your question doesn't seem to make much sense. DMA transfers have nothing to do with BARs at all, they don't come "from" or "to" one.
-- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/
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