[alsa-devel] [PATCH 1/3] new ad1836 codec driver based on asoc

Barry Song 21cnbao at gmail.com
Thu Aug 13 11:37:09 CEST 2009

On Thu, Aug 13, 2009 at 5:08 PM, Mark
Brown<broonie at opensource.wolfsonmicro.com> wrote:
> On Thu, Aug 13, 2009 at 11:41:13AM +0800, Barry Song wrote:
>> On Wed, Aug 12, 2009 at 9:46 PM, Mark
>> Brown<broonie at opensource.wolfsonmicro.com> wrote:
>> > Just "ad1836" - the fact that it's controlled via SPI is clear from the
>> > fact that this is a struct spi_driver.
>> I agree the spi structure implies the meaning of spi.  But files in
>> arch/blackfin/mach... are using names like "xxx-spi" for almost all
>> spi devices. How about keeping the coherence?
> Oh dear.  Looks like you've essentially got a choice between being
> consistent with the rest of the world and being consistent with what the
> blackfin stuff is doing.
Looks like the rest world really doesn't define a spi device with
modalias "xxx-spi" but just "xxx" in arch. So I agree we can change
blackfin stuff as Mike.

>> > The power control will be handled by DAPM but your driver still needs to
>> > restore things like the volume settings - when the driver is powered off
>> > the register settings will be forgotten.
>> My test shows registers setting doesn't lose after dac/adc shutdown :-)
> Probably your board is maintaining power to the chip even during
> suspend.
If so, all codec drivers need to save setting then restore them when
resume. The physical shutdown depends on boards great. If we get an
individual programmable PMU/LDO to control the voltage input to this
chip, I can shutdown power-input to codec physically and save the
registers when suspend,  then restore them when resume. If no this
unit, should every codec driver handle this case?

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