Re: [PATCH v1 0/2] rsnd: dts: change to use extended audio dmac register

From: jiada
Date: Thu Feb 21 2019 - 22:49:27 EST


Hi Geert


On 2019/02/20 17:10, Kuninori Morimoto wrote:

Hi Geert

According to user reference manual for R-CAR H3 and M3-W SoCs,
in order to access busif4 ~ busif7, extended audio dmac registers
(PDMASAREn, PDMADAREn, PDMACHCREn)
need to be used, rather than basic audio dmac registers
(PDMASARn, PDMADARn, PDMACHCRn)

This patch set updates H3 (= r8a7795) and M3-W (= r8a7796)
to use extended audio dmac registers

The same change should be applied for M3-N and RZ/G2M, right?

Currently only H3 and M3-W support to use busif other than busif0,
I feel currently it's only necessary to use extended audio dmac register for these SoCs

R-Car E3 and RZ/G2E already use the extended register set, as they do not
have the basic set.

For SoCs having both, this feels a bit like describing software policy, instead
of hardware, to me. Would it make sense to extend the audio bindings, and
allow describing both the basic and extended register sets, and let the driver
make the decision which one to use?

I don't think we need to use basic register.
This means extended register only is very enough.
I'm not sure why datasheet is indicating basic...

Extended audio dmac registers covers all function of basic ones,
so there is no need to use basic registers

Thanks,
Jiada

Best regards
---
Kuninori Morimoto