[PATCH 08/25] ARM: shmobile: r8a7790: sound enables Audio DMAC peri peri entry on DTSI

[Kuninori Morimoto]

Hi Arnd

> >                                 "mem_src6",     "src6_mem",
> >                                 "mem_src7",     "src7_mem",
> >                                 "mem_src8",     "src8_mem",
> > -                               "mem_src9",     "src9_mem";
> > +                               "mem_src9",     "src9_mem",
> > +
> > +                               "src0_ssiu0",           "src1_ssiu0",           "src2_ssiu0",           "src3_ssiu0",           "src4_ssiu0",
> > +                               "src0_ssiu1",           "src1_ssiu1",           "src2_ssiu1",           "src3_ssiu1",           "src4_ssiu1",
> > +                               "src0_ssiu2",           "src1_ssiu2",           "src2_ssiu2",           "src3_ssiu2",           "src4_ssiu2",
> > 
> 
> I have to note that this looks rather weird and that none of the names
> are documented in the binding.
> 
> Can you explain why this device uses over 100 DMA channels and put the
> exact naming rules into the binding?
> Do you expect all channels to be in use simultaneously?

This device has 10 sound channels, and using 3 kind of IPs.
Then, data input/output needs DMA channel which needs specific ID to using.
Above name has ID pair for it, so there is much combination. 
These specific ID is based on SoC, not board.
Sound driver / DMAEngine can get specific ID from above.

Indeed binding itself was not documented yet.
I will add it ASAP.