On Tue, Nov 17, 2015 at 9:53 AM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > On 11/17/2015 08:39 AM, Ran Shalit wrote: >> Hello, >> >> I intend to use cobalt driver as a refence for new pci v4l2 driver, >> which is required to use several input simultaneously. for this cobalt >> seems like a best starting point. >> read/write streaming will probably be suffecient (at least for the >> dirst debugging). >> The configuration in my cast is i7 core <-- pci ---> fpga. >> I see that the dma implementation is quite complex, and would like to >> ask for some tips regarding the following points related to dma issue: >> >> 1. Is it possible to do the read/write without dma (for debug as start) ? > > No. All video capture/output devices all use DMA since it would be prohibitively > expensive for the CPU to do otherwise. So just dig in and implement it. > Hi, Is the cobalt or other pci v4l device have the chip datasheet available so that we can do a reverse engineering and gain more understanding about the register read/write for the dma transactions ? I made a search but it seems that the PCIe chip datasheet for these devices is not available anywhere. Best Regards, Ran -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
