Thank for that You just made my day.
On Friday, March 11, 2016 at 9:50:09 AM UTC+11, Maxime Ripard wrote:
>
> Hi Yassin,
>
> On Wed, Mar 09, 2016 at 05:27:52PM -0800, Yassin Jaffer wrote:
> >
> > Hi everyone
> >
> > I'm working on the CSI driver.
>
> Great, it was on my TODO-list :)
>
> > I failed to understand ( lack of documentation) which DMA is used to
> > transfer from the CSI. I can only find a reference in the bsp
> > driver for the DRAM
> >
> > CPU_DRAM_PADDR_ORG = 0x40000000
> > HW_DMA_OFFSET= 0x00000000
> >
> > dma_addr_t addr_org = videobuf_to_dma_contig(vb_buf) -
> > CPU_DRAM_PADDR_ORG + HW_DMA_OFFSET;
> >
> > And in the current sunxi 3.4
> >
> > addr_org = videobuf_to_dma_contig((struct videobuf_buffer *)buf);
> > if( (addr_org&0x40000000)!=0 )
> > {
> > addr_org-=0x40000000;
> > csi_dbg(3,"csi recal mem_addr=%p\n",addr_org);
> > }
> >
> >
> > There is also a reference to the DMA in os_mem_alloc which is used by
> the
> > ISP front end.
> > mem_man->dma_addr = mem_man->phy_addr + HW_DMA_OFFSET-
> > CPU_DRAM_PADDR_ORG;
>
> It has its own DMA controller. You just have to feed it with a
> DMA-capable buffer's physical address in the FIFO Buffer registers,
> and it should just work.
>
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
>
--
You received this message because you are subscribed to the Google Groups
"linux-sunxi" 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.
